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Sample records for aldosterone-sensitive distal nephron

  1. Electroneutral absorption of NaCl by the aldosterone-sensitive distal nephron: implication for normal electrolytes homeostasis and blood pressure regulation.

    PubMed

    Eladari, Dominique; Chambrey, Régine; Picard, Nicolas; Hadchouel, Juliette

    2014-08-01

    Sodium absorption by the distal part of the nephron, i.e., the distal convoluted tubule, the connecting tubule, and the collecting duct, plays a major role in the control of homeostasis by the kidney. In this part of the nephron, sodium transport can either be electroneutral or electrogenic. The study of electrogenic Na(+) absorption, which is mediated by the epithelial sodium channel (ENaC), has been the focus of considerable interest because of its implication in sodium, potassium, and acid-base homeostasis. However, recent studies have highlighted the crucial role played by electroneutral NaCl absorption in the regulation of the body content of sodium chloride, which in turn controls extracellular fluid volume and blood pressure. Here, we review the identification and characterization of the NaCl cotransporter (NCC), the molecule accounting for the main part of electroneutral NaCl absorption in the distal nephron, and its regulators. We also discuss recent work describing the identification of a novel "NCC-like" transport system mediated by pendrin and the sodium-driven chloride/bicarbonate exchanger (NDCBE) in the β-intercalated cells of the collecting system.

  2. An unexpected journey: conceptual evolution of mechanoregulated potassium transport in the distal nephron.

    PubMed

    Carrisoza-Gaytan, Rolando; Carattino, Marcelo D; Kleyman, Thomas R; Satlin, Lisa M

    2016-02-15

    Flow-induced K secretion (FIKS) in the aldosterone-sensitive distal nephron (ASDN) is mediated by large-conductance, Ca(2+)/stretch-activated BK channels composed of pore-forming α-subunits (BKα) and accessory β-subunits. This channel also plays a critical role in the renal adaptation to dietary K loading. Within the ASDN, the cortical collecting duct (CCD) is a major site for the final renal regulation of K homeostasis. Principal cells in the ASDN possess a single apical cilium whereas the surfaces of adjacent intercalated cells, devoid of cilia, are decorated with abundant microvilli and microplicae. Increases in tubular (urinary) flow rate, induced by volume expansion, diuretics, or a high K diet, subject CCD cells to hydrodynamic forces (fluid shear stress, circumferential stretch, and drag/torque on apical cilia and presumably microvilli/microplicae) that are transduced into increases in principal (PC) and intercalated (IC) cell cytoplasmic Ca(2+) concentration that activate apical voltage-, stretch- and Ca(2+)-activated BK channels, which mediate FIKS. This review summarizes studies by ourselves and others that have led to the evolving picture that the BK channel is localized in a macromolecular complex at the apical membrane, composed of mechanosensitive apical Ca(2+) channels and a variety of kinases/phosphatases as well as other signaling molecules anchored to the cytoskeleton, and that an increase in tubular fluid flow rate leads to IC- and PC-specific responses determined, in large part, by the cell-specific composition of the BK channels.

  3. An unexpected journey: conceptual evolution of mechanoregulated potassium transport in the distal nephron

    PubMed Central

    Carrisoza-Gaytan, Rolando; Carattino, Marcelo D.; Kleyman, Thomas R.

    2016-01-01

    Flow-induced K secretion (FIKS) in the aldosterone-sensitive distal nephron (ASDN) is mediated by large-conductance, Ca2+/stretch-activated BK channels composed of pore-forming α-subunits (BKα) and accessory β-subunits. This channel also plays a critical role in the renal adaptation to dietary K loading. Within the ASDN, the cortical collecting duct (CCD) is a major site for the final renal regulation of K homeostasis. Principal cells in the ASDN possess a single apical cilium whereas the surfaces of adjacent intercalated cells, devoid of cilia, are decorated with abundant microvilli and microplicae. Increases in tubular (urinary) flow rate, induced by volume expansion, diuretics, or a high K diet, subject CCD cells to hydrodynamic forces (fluid shear stress, circumferential stretch, and drag/torque on apical cilia and presumably microvilli/microplicae) that are transduced into increases in principal (PC) and intercalated (IC) cell cytoplasmic Ca2+ concentration that activate apical voltage-, stretch- and Ca2+-activated BK channels, which mediate FIKS. This review summarizes studies by ourselves and others that have led to the evolving picture that the BK channel is localized in a macromolecular complex at the apical membrane, composed of mechanosensitive apical Ca2+ channels and a variety of kinases/phosphatases as well as other signaling molecules anchored to the cytoskeleton, and that an increase in tubular fluid flow rate leads to IC- and PC-specific responses determined, in large part, by the cell-specific composition of the BK channels. PMID:26632600

  4. The ClC-K2 Chloride Channel Is Critical for Salt Handling in the Distal Nephron.

    PubMed

    Hennings, J Christopher; Andrini, Olga; Picard, Nicolas; Paulais, Marc; Huebner, Antje K; Cayuqueo, Irma Karen Lopez; Bignon, Yohan; Keck, Mathilde; Cornière, Nicolas; Böhm, David; Jentsch, Thomas J; Chambrey, Régine; Teulon, Jacques; Hübner, Christian A; Eladari, Dominique

    2017-01-01

    Chloride transport by the renal tubule is critical for blood pressure (BP), acid-base, and potassium homeostasis. Chloride uptake from the urinary fluid is mediated by various apical transporters, whereas basolateral chloride exit is thought to be mediated by ClC-Ka/K1 and ClC-Kb/K2, two chloride channels from the ClC family, or by KCl cotransporters from the SLC12 gene family. Nevertheless, the localization and role of ClC-K channels is not fully resolved. Because inactivating mutations in ClC-Kb/K2 cause Bartter syndrome, a disease that mimics the effects of the loop diuretic furosemide, ClC-Kb/K2 is assumed to have a critical role in salt handling by the thick ascending limb. To dissect the role of this channel in detail, we generated a mouse model with a targeted disruption of the murine ortholog ClC-K2. Mutant mice developed a Bartter syndrome phenotype, characterized by renal salt loss, marked hypokalemia, and metabolic alkalosis. Patch-clamp analysis of tubules isolated from knockout (KO) mice suggested that ClC-K2 is the main basolateral chloride channel in the thick ascending limb and in the aldosterone-sensitive distal nephron. Accordingly, ClC-K2 KO mice did not exhibit the natriuretic response to furosemide and exhibited a severely blunted response to thiazide. We conclude that ClC-Kb/K2 is critical for salt absorption not only by the thick ascending limb, but also by the distal convoluted tubule.

  5. Differential regulation of ROMK (Kir1.1) in distal nephron segments by dietary potassium.

    PubMed

    Wade, James B; Fang, Liang; Coleman, Richard A; Liu, Jie; Grimm, P Richard; Wang, Tong; Welling, Paul A

    2011-06-01

    ROMK channels are well-known to play a central role in renal K secretion, but the absence of highly specific and avid-ROMK antibodies has presented significant roadblocks toward mapping the extent of expression along the entire distal nephron and determining whether surface density of these channels is regulated in response to physiological stimuli. Here, we prepared new ROMK antibodies verified to be highly specific, using ROMK knockout mice as a control. Characterization with segmental markers revealed a more extensive pattern of ROMK expression along the entire distal nephron than previously thought, localizing to distal convoluted tubule regions, DCT1 and DCT2; the connecting tubule (CNT); and cortical collecting duct (CD). ROMK was diffusely distributed in intracellular compartments and at the apical membrane of each tubular region. Apical labeling was significantly increased by high-K diet in DCT2, CNT1, CNT2, and CD (P < 0.05) but not in DCT1. Consistent with the large increase in apical ROMK, dramatically increased mature glycosylation was observed following dietary potassium augmentation. We conclude 1) our new antibody provides a unique tool to characterize ROMK channel localization and expression and 2) high-K diet causes a large increase in apical expression of ROMK in DCT2, CNT, and CD but not in DCT1, indicating that different regulatory mechanisms are involved in K diet-regulated ROMK channel functions in the distal nephron.

  6. Localization of connexin 30 in the luminal membrane of cells in the distal nephron.

    PubMed

    McCulloch, Fiona; Chambrey, Régine; Eladari, Dominique; Peti-Peterdi, János

    2005-12-01

    Several isoforms of the gap junction protein connexin (Cx) have been identified in a variety of tissues that communicate intercellular signals between adjacent cells. In the kidney, Cx37, Cx40, and Cx43 are localized in the vasculature, glomerulus, and tubular segments in a punctuate pattern, typical of classic gap junction channels. We performed immunohistochemistry in the mouse, rat, and rabbit kidney to study the localization of Cx30 protein, a new member of the Cx family. The vasculature, glomerulus, and proximal nephron segments were devoid of staining in all three species. Unexpectedly, Cx30 was found throughout the luminal membrane of select cells in the distal nephron. Expression of Cx30 was highest in the rat, which also showed some diffuse cytosolic labeling, continuous from the medullary thick ascending limb to the collecting duct system, and with the highest level in the distal convoluted tubule. Labeling in the mouse and rabbit was much less, limited to intercalated cells in the connecting segment and cortical collecting duct, where the apical signal was particularly strong. A high-salt-containing diet and culture medium upregulated Cx30 expression in the rat inner medulla and in M1 cells, respectively. The distinct, continuous labeling of the luminal plasma membrane and upregulation by high salt suggest that Cx30 may function as a hemichannel involved in the regulation of salt reabsorption in the distal nephron.

  7. Enhanced Distal Nephron Sodium Reabsorption in Chronic Angiotensin II Infused Mice

    PubMed Central

    Zhao, Di; Seth, Dale M.; Navar, L. Gabriel

    2009-01-01

    Chronic angiotensin II (Ang II) infusions enhance urinary excretion of angiotensinogen suggesting augmentation of distal nephron sodium reabsorption. To assess if chronic Ang II infusions (15 ng/min for 2 weeks) enhance distal nephron sodium reabsorption, we compared sodium excretion before and following blockade of the two main distal nephron sodium transporters by iv amiloride (5 mg/kg body weight) plus bendroflumethiazide (12 mg/kg body weight) in male C57/BL6 anesthetized control mice (n=10) and in chronic Ang II-infused mice (n=8). Chronic Ang II infusions increased systolic blood pressure to 141±6 mm Hg compared to 106±4 mm Hg in control mice. After anesthesia, mean arterial pressure averaged 97±4 mm Hg in chronic Ang II-infused mice compared with 94±3 mm Hg in control mice allowing comparison of renal function at similar arterial pressures. Ang II-infused mice had lower urinary sodium excretion (0.16±0.04 versus 0.30±0.05 μEq/min, P<0.05), higher distal sodium reabsorption (1.74±0.18 versus 1.12±0.18 μEq/min, P<0.05) and higher fractional reabsorption of distal sodium delivery (91.1±1.8% versus 77.9±4.3 %, P<0.05) than control mice. Urinary Ang II concentrations, measured during distal blockade, were greater in Ang II infused mice (1235.0±277.2 versus 468.9±146.9 fmol/ml, P<0.05). In chronic Ang II-infused mice treated with spironolactone (n=5), fractional reabsorption of distal sodium delivery was similarly augmented as in chronic Ang II infused mice (94.6±1.7%, P<0.01). These data provide in vivo evidence that there is enhanced distal sodium reabsorption dependent on sodium channel and Na+-Cl− cotransporter activity and increased urinary Ang II concentrations in mice infused chronically with Ang II. PMID:19487583

  8. Unique chloride-sensing properties of WNK4 permit the distal nephron to modulate potassium homeostasis.

    PubMed

    Terker, Andrew S; Zhang, Chong; Erspamer, Kayla J; Gamba, Gerardo; Yang, Chao-Ling; Ellison, David H

    2016-01-01

    Dietary potassium deficiency activates thiazide-sensitive sodium chloride cotransport along the distal nephron. This may explain, in part, the hypertension and cardiovascular mortality observed in individuals who consume a low-potassium diet. Recent data suggest that plasma potassium affects the distal nephron directly by influencing intracellular chloride, an inhibitor of the with-no-lysine kinase (WNK)-Ste20p-related proline- and alanine-rich kinase (SPAK) pathway. As previous studies used extreme dietary manipulations, we sought to determine whether the relationship between potassium and NaCl cotransporter (NCC) is physiologically relevant and clarify the mechanisms involved. We report that modest changes in both dietary and plasma potassium affect NCC in vivo. Kinase assay studies showed that chloride inhibits WNK4 kinase activity at lower concentrations than it inhibits activity of WNK1 or WNK3. Also, chloride inhibited WNK4 within the range of distal cell chloride concentration. Mutation of a previously identified WNK chloride-binding motif converted WNK4 effects on SPAK from inhibitory to stimulatory in mammalian cells. Disruption of this motif in WNKs 1, 3, and 4 had different effects on NCC, consistent with the three WNKs having different chloride sensitivities. Thus, potassium effects on NCC are graded within the physiological range, which explains how unique chloride-sensing properties of WNK4 enable it to mediate effects of potassium on NCC in vivo.

  9. Insulin activates single amiloride-blockable Na channels in a distal nephron cell line (A6).

    PubMed

    Marunaka, Y; Hagiwara, N; Tohda, H

    1992-09-01

    Using the patch-clamp technique, we studied the effect of insulin on an amiloride-blockable Na channel in the apical membrane of a distal nephron cell line (A6) cultured on permeable collagen films for 10-14 days. NPo (N, number of channels per patch membrane; Po, average value of open probability of individual channels in the patch) under baseline conditions was 0.88 +/- 0.12 (SE)(n = 17). After making cell-attached patches on the apical membrane which contained Na channels, insulin (1 mU/ml) was applied to the serosal bath. While maintaining the cell-attached patch, NPo significantly increased to 1.48 +/- 0.19 (n = 17; P less than 0.001) after 5-10 min of insulin application. The open probability of Na channels was 0.39 +/- 0.01 (n = 38) under baseline condition, and increased to 0.66 +/- 0.03 (n = 38, P less than 0.001) after addition of insulin. The baseline single-channel conductance was 4pS, and neither the single-channel conductance nor the current-voltage relationship was significantly changed by insulin. These results indicate that insulin increases Na absorption in the distal nephron by increasing the open probability of the amiloride-blockable Na channel.

  10. Sex differences in proximal and distal nephron function contribute to the mechanism of idiopathic hypercalcuria in calcium stone formers.

    PubMed

    Ko, Benjamin; Bergsland, Kristin; Gillen, Daniel L; Evan, Andrew P; Clark, Daniel L; Baylock, Jaime; Coe, Fredric L; Worcester, Elaine M

    2015-07-01

    Idiopathic hypercalciuria (IH) is a common familial trait among patients with calcium nephrolithiasis. Previously, we have demonstrated that hypercalciuria is primarily due to reduced renal proximal and distal tubule calcium reabsorption. Here, using measurements of the clearances of sodium, calcium, and endogenous lithium taken from the General Clinical Research Center, we test the hypothesis that patterns of segmental nephron tubule calcium reabsorption differ between the sexes in IH and normal subjects. When the sexes are compared, we reconfirm the reduced proximal and distal calcium reabsorption. In IH women, distal nephron calcium reabsorption is decreased compared to normal women. In IH men, proximal tubule calcium reabsorption falls significantly, with a more modest reduction in distal calcium reabsorption compared to normal men. Additionally, we demonstrate that male IH patients have lower systolic blood pressures than normal males. We conclude that women and men differ in the way they produce the hypercalciuria of IH, with females reducing distal reabsorption and males primarily reducing proximal tubule function.

  11. Augmented bicarbonate reabsorption by both the proximal and distal nephron maintains chloride-deplete metabolic alkalosis in rats.

    PubMed Central

    Wesson, D E

    1989-01-01

    Whether augmented bicarbonate reabsorption by renal tubular epithelium contributes to the maintenance of chloride-deplete metabolic alkalosis is not clear. This study used free-flow micropuncture to investigate bicarbonate reabsorption by surface nephron segments in a rat model of diuretic-induced alkalosis compared to control. The proximal and distal nephron of the alkalotic animals had higher values for both delivered load to and absolute reabsorption from these segments. The proximal tubules of alkalotic and control animals had similar values for the slopes of the linear regression of delivered load vs. reabsorption and for the bicarbonate tubular fluid to plasma (TF/P) ratio at the late proximal tubule. By contrast, the corresponding analysis for the distal segment of alkalotic animals revealed a greater slope (0.98 vs. 0.81, P less than 0.003) and a smaller bicarbonate TF/P ratio at the late distal tubule (0.10 vs. 0.16, P less than 0.006). The data indicate that augmented bicarbonate reabsorption by both the proximal and distal nephron contributes to maintaining the alkalosis of this model. The data suggest primary stimulation of bicarbonate reabsorption in the distal nephron and load-dependent reabsorption in the proximal tubule. PMID:2808701

  12. Effects of aldosterone and potassium-sparing diuretics on electrical potential differences across the distal nephron.

    PubMed Central

    Gross, J B; Kokko, J P

    1977-01-01

    We have previously shown that the transtubular potential of the rabbit cortical collecting tubule varies in concert with changes in plasma mineralocorticoid levels, while the potential of the distal convoluted tubule is invariant with such changes. In the present studies we have examined the effects of in vitro addition of d-aldosterone to isolated tubules, as well as the effects of triamterene and spirolactone. d-Aldosterone (0.2 mum added to the perfusate or 1 muM added to the bathing medium) resulted in a marked stimulation of the transtubular potential difference (lumen-negative) after a short latent period. d-Aldosterone had no effect on the potential difference of distal convoluted tubules of intact or adrenalectomized rabbits. Both the magnitude of the response and the length of the latent period in the cortical collecting tubule after aldosterone were markedly temperature-dependent. Triamterene caused a gradual but reversible inhibition of the potential difference in the cortical collecting tubule but had no effect in the distal tubule. Spirolactone, when added before aldosterone, blocked the electrical response to the hormone in the cortical collecting tubule, and produced a gradual inhibition of the potential difference in mineralocorticoid-stimulated tubules. Spirolactone had no effect on the potential difference of the distal tubule. We conclude that (a) the influence of aldosterone on the potential across the distal nephron is restricted to the distal convoluted tubule, (b) the electrical response to aldosterone and the latent period are temperature-dependent, (c) the response to aldosterone is blocked by spirolactone, and (d) triamterene inhibits the potential difference only in the cortical collecting tubule. PMID:830667

  13. Vasopressin regulation of sodium transport in the distal nephron and collecting duct.

    PubMed

    Kortenoeven, M L A; Pedersen, N B; Rosenbaek, L L; Fenton, R A

    2015-08-15

    Arginine vasopressin (AVP) is released from the posterior pituitary gland during states of hyperosmolality or hypovolemia. AVP is a peptide hormone, with antidiuretic and antinatriuretic properties. It allows the kidneys to increase body water retention predominantly by increasing the cell surface expression of aquaporin water channels in the collecting duct alongside increasing the osmotic driving forces for water reabsorption. The antinatriuretic effects of AVP are mediated by the regulation of sodium transport throughout the distal nephron, from the thick ascending limb through to the collecting duct, which in turn partially facilitates osmotic movement of water. In this review, we will discuss the regulatory role of AVP in sodium transport and summarize the effects of AVP on various molecular targets, including the sodium-potassium-chloride cotransporter NKCC2, the thiazide-sensitive sodium-chloride cotransporter NCC, and the epithelial sodium channel ENaC.

  14. Discrete control of TRPV4 channel function in the distal nephron by protein kinases A and C.

    PubMed

    Mamenko, Mykola; Zaika, Oleg L; Boukelmoune, Nabila; Berrout, Jonathan; O'Neil, Roger G; Pochynyuk, Oleh

    2013-07-12

    We have recently documented that the Ca(2+)-permeable TRPV4 channel, which is abundantly expressed in distal nephron cells, mediates cellular Ca(2+) responses to elevated luminal flow. In this study, we combined Fura-2-based [Ca(2+)]i imaging with immunofluorescence microscopy in isolated split-opened distal nephrons of C57BL/6 mice to probe the molecular determinants of TRPV4 activity and subcellular distribution. We found that activation of the PKC pathway with phorbol 12-myristate 13-acetate significantly increased [Ca(2+)]i responses to flow without affecting the subcellular distribution of TRPV4. Inhibition of PKC with bisindolylmaleimide I diminished cellular responses to elevated flow. In contrast, activation of the PKA pathway with forskolin did not affect TRPV4-mediated [Ca(2+)]i responses to flow but markedly shifted the subcellular distribution of the channel toward the apical membrane. These actions were blocked with the specific PKA inhibitor H-89. Concomitant activation of the PKA and PKC cascades additively enhanced the amplitude of flow-induced [Ca(2+)]i responses and greatly increased basal [Ca(2+)]i levels, indicating constitutive TRPV4 activation. This effect was precluded by the selective TRPV4 antagonist HC-067047. Therefore, the functional status of the TRPV4 channel in the distal nephron is regulated by two distinct signaling pathways. Although the PKA-dependent cascade promotes TRPV4 trafficking and translocation to the apical membrane, the PKC-dependent pathway increases the activity of the channel on the plasma membrane.

  15. Bicarbonate promotes BK-α/β4-mediated K excretion in the renal distal nephron.

    PubMed

    Cornelius, Ryan J; Wen, Donghai; Hatcher, Lori I; Sansom, Steven C

    2012-12-01

    Ca-activated K channels (BK), which are stimulated by high distal nephron flow, are utilized during high-K conditions to remove excess K. Because BK predominantly reside with BK-β4 in acid/base-transporting intercalated cells (IC), we determined whether BK-β4 knockout mice (β4KO) exhibit deficient K excretion when consuming a high-K alkaline diet (HK-alk) vs. high-K chloride diet (HK-Cl). When wild type (WT) were placed on HK-alk, but not HK-Cl, renal BK-β4 expression increased (Western blot). When WT and β4KO were placed on HK-Cl, plasma K concentration ([K]) was elevated compared with control K diets; however, K excretion was not different between WT and β4KO. When HK-alk was consumed, the plasma [K] was lower and K clearance was greater in WT compared with β4KO. The urine was alkaline in mice on HK-alk; however, urinary pH was not different between WT and β4KO. Immunohistochemical analysis of pendrin and V-ATPase revealed the same increases in β-IC, comparing WT and β4KO on HK-alk. We found an amiloride-sensitive reduction in Na excretion in β4KO, compared with WT, on HK-alk, indicating enhanced Na reabsorption as a compensatory mechanism to secrete K. Treating mice with an alkaline, Na-deficient, high-K diet (LNaHK) to minimize Na reabsorption exaggerated the defective K handling of β4KO. When WT on LNaHK were given NH(4)Cl in the drinking water, K excretion was reduced to the magnitude of β4KO on LNaHK. These results show that WT, but not β4KO, efficiently excretes K on HK-alk but not on HK-Cl and suggest that BK-α/β4-mediated K secretion is promoted by bicarbonaturia.

  16. Proximal Nephron

    PubMed Central

    Zhuo, Jia L.; Li, Xiao C.

    2013-01-01

    The kidney plays a fundamental role in maintaining body salt and fluid balance and blood pressure homeostasis through the actions of its proximal and distal tubular segments of nephrons. However, proximal tubules are well recognized to exert a more prominent role than distal counterparts. Proximal tubules are responsible for reabsorbing approximately 65% of filtered load and most, if not all, of filtered amino acids, glucose, solutes, and low molecular weight proteins. Proximal tubules also play a key role in regulating acid-base balance by reabsorbing approximately 80% of filtered bicarbonate. The purpose of this review article is to provide a comprehensive overview of new insights and perspectives into current understanding of proximal tubules of nephrons, with an emphasis on the ultrastructure, molecular biology, cellular and integrative physiology, and the underlying signaling transduction mechanisms. The review is divided into three closely related sections. The first section focuses on the classification of nephrons and recent perspectives on the potential role of nephron numbers in human health and diseases. The second section reviews recent research on the structural and biochemical basis of proximal tubular function. The final section provides a comprehensive overview of new insights and perspectives in the physiological regulation of proximal tubular transport by vasoactive hormones. In the latter section, attention is particularly paid to new insights and perspectives learnt from recent cloning of transporters, development of transgenic animals with knockout or knockin of a particular gene of interest, and mapping of signaling pathways using microarrays and/or physiological proteomic approaches. PMID:23897681

  17. Acute saline expansion increases nephron filtration and distal flow rate but maintains tubuloglomerular feedback responsiveness: role of adenosine A1 receptors

    PubMed Central

    Singh, Prabhleen; Deng, Aihua; Thomson, Scott C.; Vallon, Volker

    2012-01-01

    Temporal adaptation of tubuloglomerular feedback (TGF) permits readjustment of the relationship of nephron filtration rate [single nephron glomerular filtration rate (SNGFR)] and early distal tubular flow rate (VED) while maintaining TGF responsiveness. We used closed-loop assessment of TGF in hydropenia and after acute saline volume expansion (SE; 10% body wt over 1 h) to determine whether 1) temporal adaptation of TGF occurs, 2) adenosine A1 receptors (A1R) mediate TGF responsiveness, and 3) inhibition of TGF affects SNGFR, VED, or urinary excretion under these conditions. SNGFR was evaluated in Fromter-Wistar rats by micropuncture in 1) early distal tubules (ambient flow at macula densa), 2) recollected from early distal tubules while 12 nl/min isotonic fluid was added to late proximal tubule (increased flow to macula densa), and 3) from proximal tubules of same nephrons (zero flow to macula densa). SE increased both ambient SNGFR and VED compared with hydropenia, whereas TGF responsiveness (proximal-distal difference in SNGFR, distal SNGFR response to adding fluid to proximal tubule) was maintained, demonstrating TGF adaptation. A1R blockade completely inhibited TGF responsiveness during SE and made VED more susceptible to perturbation in proximal tubular flow, but did not alter ambient SNGFR or VED. Greater urinary excretion of fluid and Na+ with A1R blockade may reflect additional effects on the distal nephron in hydropenia and SE. In conclusion, A1R-independent mechanisms adjust SNGFR and VED to higher values after SE, which facilitates fluid and Na+ excretion. Concurrently, TGF adapts and stabilizes early distal delivery at the new setpoint in an A1R-dependent mechanism. PMID:22622464

  18. Localization of the succinate receptor in the distal nephron and its signaling in polarized MDCK cells.

    PubMed

    Robben, Joris H; Fenton, Robert A; Vargas, Sarah L; Schweer, Horst; Peti-Peterdi, Janos; Deen, Peter M T; Milligan, Graeme

    2009-12-01

    When the succinate receptor (SUCNR1) is activated in the afferent arterioles of the glomerulus it increases renin release and induces hypertension. To study its location in other nephron segments and its role in kidney function, we performed immunohistochemical analysis and found that SUCNR1 is located in the luminal membrane of macula densa cells of the juxtaglomerular apparatus in close proximity to renin-producing granular cells, the cortical thick ascending limb, and cortical and inner medullary collecting duct cells. In order to study its signaling, SUCNR1 was stably expressed in Madin-Darby Canine Kidney (MDCK) cells, where it localized to the apical membrane. Activation of the cells by succinate caused Gq and Gi-mediated intracellular calcium mobilization, transient phosphorylation of extracellular regulated kinase (ERK)1/2 and the release of arachidonic acid along with prostaglandins E2 and I2. Signaling was desensitized without receptor internalization but rapidly resensitized upon succinate removal. Immunohistochemical evidence of phosphorylated ERK1/2 was found in cortical collecting duct cells of wild type but not SUCNR1 knockout streptozotocin-induced diabetic mice, indicating in vivo relevance. Since urinary succinate concentrations in health and disease are in the activation range of the SUCNR1, this receptor can sense succinate in the luminal fluid. Our study suggests that changes in the luminal succinate concentration may regulate several aspects of renal function.

  19. NHA2 is expressed in distal nephron and regulated by dietary sodium.

    PubMed

    Kondapalli, Kalyan C; Todd Alexander, R; Pluznick, Jennifer L; Rao, Rajini

    2016-12-01

    Increased renal reabsorption of sodium is a significant risk factor in hypertension. An established clinical marker for essential hypertension is elevated sodium lithium countertransport (SLC) activity. NHA2 is a newly identified Na(+)(Li(+))/H(+) antiporter with potential genetic links to hypertension, which has been shown to mediate SLC activity and H(+)-coupled Na(+)(Li(+)) efflux in kidney-derived MDCK cells. To evaluate a putative role in sodium homeostasis, we determined the effect of dietary salt on NHA2. In murine kidney sections, NHA2 localized apically to distal convoluted (both DCT1 and 2) and connecting tubules, partially overlapping in distribution with V-ATPase, AQP2, and NCC1 transporters. Mice fed a diet high in sodium chloride showed elevated transcripts and expression of NHA2 protein. We propose a model in which NHA2 plays a dual role in salt reabsorption or secretion, depending on the coupling ion (sodium or protons). The identified novel regulation of Na(+)/H(+) antiporter in the kidney suggests new roles in salt homeostasis and disease.

  20. Prostaglandin-E2 Mediated Increase in Calcium and Phosphate Excretion in a Mouse Model of Distal Nephron Salt Wasting

    PubMed Central

    Soleimani, Manoocher; Barone, Sharon; Xu, Jie; Alshahrani, Saeed; Brooks, Marybeth; McCormack, Francis X.; Smith, Roger D.; Zahedi, Kamyar

    2016-01-01

    Contribution of salt wasting and volume depletion to the pathogenesis of hypercalciuria and hyperphosphaturia is poorly understood. Pendrin/NCC double KO (pendrin/NCC-dKO) mice display severe salt wasting under basal conditions and develop profound volume depletion, prerenal renal failure, and metabolic alkalosis and are growth retarded. Microscopic examination of the kidneys of pendrin/NCC-dKO mice revealed the presence of calcium phosphate deposits in the medullary collecting ducts, along with increased urinary calcium and phosphate excretion. Confirmatory studies revealed decreases in the expression levels of sodium phosphate transporter-2 isoforms a and c, increases in the expression of cytochrome p450 family 4a isotypes 12 a and b, as well as prostaglandin E synthase 1, and cyclooxygenases 1 and 2. Pendrin/NCC-dKO animals also had a significant increase in urinary prostaglandin E2 (PGE-2) and renal content of 20-hydroxyeicosatetraenoic acid (20-HETE) levels. Pendrin/NCC-dKO animals exhibit reduced expression levels of the sodium/potassium/2chloride co-transporter 2 (NKCC2) in their medullary thick ascending limb. Further assessment of the renal expression of NKCC2 isoforms by quantitative real time PCR (qRT-PCR) reveled that compared to WT mice, the expression of NKCC2 isotype F was significantly reduced in pendrin/NCC-dKO mice. Provision of a high salt diet to rectify volume depletion or inhibition of PGE-2 synthesis by indomethacin, but not inhibition of 20-HETE generation by HET0016, significantly improved hypercalciuria and salt wasting in pendrin/NCC dKO mice. Both high salt diet and indomethacin treatment also corrected the alterations in NKCC2 isotype expression in pendrin/NCC-dKO mice. We propose that severe salt wasting and volume depletion, irrespective of the primary originating nephron segment, can secondarily impair the reabsorption of salt and calcium in the thick ascending limb of Henle and/or proximal tubule, and reabsorption of sodium and

  1. Prostaglandin-E2 Mediated Increase in Calcium and Phosphate Excretion in a Mouse Model of Distal Nephron Salt Wasting.

    PubMed

    Soleimani, Manoocher; Barone, Sharon; Xu, Jie; Alshahrani, Saeed; Brooks, Marybeth; McCormack, Francis X; Smith, Roger D; Zahedi, Kamyar

    2016-01-01

    Contribution of salt wasting and volume depletion to the pathogenesis of hypercalciuria and hyperphosphaturia is poorly understood. Pendrin/NCC double KO (pendrin/NCC-dKO) mice display severe salt wasting under basal conditions and develop profound volume depletion, prerenal renal failure, and metabolic alkalosis and are growth retarded. Microscopic examination of the kidneys of pendrin/NCC-dKO mice revealed the presence of calcium phosphate deposits in the medullary collecting ducts, along with increased urinary calcium and phosphate excretion. Confirmatory studies revealed decreases in the expression levels of sodium phosphate transporter-2 isoforms a and c, increases in the expression of cytochrome p450 family 4a isotypes 12 a and b, as well as prostaglandin E synthase 1, and cyclooxygenases 1 and 2. Pendrin/NCC-dKO animals also had a significant increase in urinary prostaglandin E2 (PGE-2) and renal content of 20-hydroxyeicosatetraenoic acid (20-HETE) levels. Pendrin/NCC-dKO animals exhibit reduced expression levels of the sodium/potassium/2chloride co-transporter 2 (NKCC2) in their medullary thick ascending limb. Further assessment of the renal expression of NKCC2 isoforms by quantitative real time PCR (qRT-PCR) reveled that compared to WT mice, the expression of NKCC2 isotype F was significantly reduced in pendrin/NCC-dKO mice. Provision of a high salt diet to rectify volume depletion or inhibition of PGE-2 synthesis by indomethacin, but not inhibition of 20-HETE generation by HET0016, significantly improved hypercalciuria and salt wasting in pendrin/NCC dKO mice. Both high salt diet and indomethacin treatment also corrected the alterations in NKCC2 isotype expression in pendrin/NCC-dKO mice. We propose that severe salt wasting and volume depletion, irrespective of the primary originating nephron segment, can secondarily impair the reabsorption of salt and calcium in the thick ascending limb of Henle and/or proximal tubule, and reabsorption of sodium and

  2. ABCC1 Is Related to the Protection of the Distal Nephron against Hyperosmolality and High Sodium Environment: Possible Implications for Cancer Chemotherapy

    PubMed Central

    Fonseca, Leonardo M.; Alvarez, Adriana B.; Rodrigues, Rachel C.; Santos, Diego H. F.; Lopes, Anibal G.; Capella, Marcia A. M.

    2013-01-01

    Aims Glutathione (GSH) plays an important role in protecting cells against oxidative damage. ABCC1 protein transports GSH. Although this protein is largely studied in cancer, due to multidrug resistance phenotype, its role in the tubular cells of the kidney is unknown. The goal of this study was to find out whether ABCC1 has a role in protecting cells from the distal nephron against the stress caused by high medullar osmolality. Main Methods MA104 cells were treated with high concentrations of sodium chloride, urea, or both to raise the osmolality of the culture medium. Cell viability was accessed by MTT and trypan blue assays. ABCC1 expression and extrusion of carboxi-fluorescein (CF), a fluorescent ABCC1 substrate, were measured by flow cytometry. Key Findings Incubation of MA104 cells in a high sodium concentration medium resulted in changes in cell granularity and altered expression and activity of ABCC1. Urea did not alter ABCC1 expression or activity, but reversed the observed NaCl effects. High sodium concentrations also had a negative effect on cell viability and urea also protected cells against this effect. Significance Our findings demonstrate that ABCC1 plays a significant role in the protection of kidney epithelial cells against the stress caused by high sodium environment present in renal medulla. PMID:23840808

  3. Dual regulation of the native ClC-K2 chloride channel in the distal nephron by voltage and pH

    PubMed Central

    Pinelli, Laurent; Nissant, Antoine; Edwards, Aurélie; Paulais, Marc

    2016-01-01

    ClC-K2, a member of the ClC family of Cl− channels and transporters, forms the major basolateral Cl− conductance in distal nephron epithelial cells and therefore plays a central role in renal Cl− absorption. However, its regulation remains largely unknown because of the fact that recombinant ClC-K2 has not yet been studied at the single-channel level. In the present study, we investigate the effects of voltage, pH, Cl−, and Ca2+ on native ClC-K2 in the basolateral membrane of intercalated cells from the mouse connecting tubule. The ∼10-pS channel shows a steep voltage dependence such that channel activity increases with membrane depolarization. Intracellular pH (pHi) and extracellular pH (pHo) differentially modulate the voltage dependence curve: alkaline pHi flattens the curve by causing an increase in activity at negative voltages, whereas alkaline pHo shifts the curve toward negative voltages. In addition, pHi, pHo, and extracellular Ca2+ strongly increase activity, mainly because of an increase in the number of active channels with a comparatively minor effect on channel open probability. Furthermore, voltage alters both the number of active channels and their open probability, whereas intracellular Cl− has little influence. We propose that changes in the number of active channels correspond to them entering or leaving an inactivated state, whereas modulation of open probability corresponds to common gating by these channels. We suggest that pH, through the combined effects of pHi and pHo on ClC-K2, might be a key regulator of NaCl absorption and Cl−/HCO3− exchange in type B intercalated cells. PMID:27574292

  4. Dual regulation of the native ClC-K2 chloride channel in the distal nephron by voltage and pH.

    PubMed

    Pinelli, Laurent; Nissant, Antoine; Edwards, Aurélie; Lourdel, Stéphane; Teulon, Jacques; Paulais, Marc

    2016-09-01

    ClC-K2, a member of the ClC family of Cl(-) channels and transporters, forms the major basolateral Cl(-) conductance in distal nephron epithelial cells and therefore plays a central role in renal Cl(-) absorption. However, its regulation remains largely unknown because of the fact that recombinant ClC-K2 has not yet been studied at the single-channel level. In the present study, we investigate the effects of voltage, pH, Cl(-), and Ca(2+) on native ClC-K2 in the basolateral membrane of intercalated cells from the mouse connecting tubule. The ∼10-pS channel shows a steep voltage dependence such that channel activity increases with membrane depolarization. Intracellular pH (pHi) and extracellular pH (pHo) differentially modulate the voltage dependence curve: alkaline pHi flattens the curve by causing an increase in activity at negative voltages, whereas alkaline pHo shifts the curve toward negative voltages. In addition, pHi, pHo, and extracellular Ca(2+) strongly increase activity, mainly because of an increase in the number of active channels with a comparatively minor effect on channel open probability. Furthermore, voltage alters both the number of active channels and their open probability, whereas intracellular Cl(-) has little influence. We propose that changes in the number of active channels correspond to them entering or leaving an inactivated state, whereas modulation of open probability corresponds to common gating by these channels. We suggest that pH, through the combined effects of pHi and pHo on ClC-K2, might be a key regulator of NaCl absorption and Cl(-)/HCO3 (-) exchange in type B intercalated cells.

  5. Synchronization phenomena in nephron-nephron interaction

    NASA Astrophysics Data System (ADS)

    Holstein-Rathlou, Niels-Henrik; Yip, Kay-Pong; Sosnovtseva, Olga V.; Mosekilde, Erik

    2001-06-01

    Experimental data for tubular pressure oscillations in rat kidneys are analyzed in order to examine the different types of synchronization that can arise between neighboring functional units. For rats with normal blood pressure, the individual unit (the nephron) typically exhibits regular oscillations in its tubular pressure and flow variations. For such rats, both in-phase and antiphase synchronization can be demonstrated in the experimental data. For spontaneously hypertensive rats, where the pressure variations in the individual nephrons are highly irregular, signs of chaotic phase and frequency synchronization can be observed. Accounting for a hemodynamic as well as for a vascular coupling between nephrons that share a common interlobular artery, we develop a mathematical model of the pressure and flow regulation in a pair of adjacent nephrons. We show that this model, for appropriate values of the parameters, can reproduce the different types of experimentally observed synchronization.

  6. Osmotic stress regulates mineralocorticoid receptor expression in a novel aldosterone-sensitive cortical collecting duct cell line.

    PubMed

    Viengchareun, Say; Kamenicky, Peter; Teixeira, Marie; Butlen, Daniel; Meduri, Geri; Blanchard-Gutton, Nicolas; Kurschat, Christine; Lanel, Aurélie; Martinerie, Laetitia; Sztal-Mazer, Shoshana; Blot-Chabaud, Marcel; Ferrary, Evelyne; Cherradi, Nadia; Lombès, Marc

    2009-12-01

    Aldosterone effects are mediated by the mineralocorticoid receptor (MR), a transcription factor highly expressed in the distal nephron. Given that MR expression level constitutes a key element controlling hormone responsiveness, there is much interest in elucidating the molecular mechanisms governing MR expression. To investigate whether hyper- or hypotonicity could affect MR abundance, we established by targeted oncogenesis a novel immortalized cortical collecting duct (CCD) cell line and examined the impact of osmotic stress on MR expression. KC3AC1 cells form domes, exhibit a high transepithelial resistance, express 11beta-hydroxysteroid dehydrogenase 2 and functional endogenous MR, which mediates aldosterone-stimulated Na(+) reabsorption through the epithelial sodium channel activation. MR expression is tightly regulated by osmotic stress. Hypertonic conditions induce expression of tonicity-responsive enhancer binding protein, an osmoregulatory transcription factor capable of binding tonicity-responsive enhancer response elements located in MR regulatory sequences. Surprisingly, hypertonicity leads to a severe reduction in MR transcript and protein levels. This is accompanied by a concomitant tonicity-induced expression of Tis11b, a mRNA-destabilizing protein that, by binding to the AU-rich sequences of the 3'-untranslated region of MR mRNA, may favor hypertonicity-dependent degradation of labile MR transcripts. In sharp contrast, hypotonicity causes a strong increase in MR transcript and protein levels. Collectively, we demonstrate for the first time that optimal adaptation of CCD cells to changes in extracellular fluid composition is accompanied by drastic modification in MR abundance via transcriptional and posttranscriptional mechanisms. Osmotic stress-regulated MR expression may represent an important molecular determinant for cell-specific MR action, most notably in renal failure, hypertension, or mineralocorticoid resistance.

  7. The nephron (pro)renin receptor: function and significance.

    PubMed

    Ramkumar, Nirupama; Kohan, Donald E

    2016-12-01

    The (pro)renin receptor (PRR) is a multifunctional protein that is part of the renin-angiotensin system and is an important accessory molecule for the vacuolar H(+)-ATPase. The PRR is widely expressed in the kidney with relatively high abundance in the distal nephron. Determining the physiological relevance of the PRR has been challenging due to early lethality in whole animal and cell-specific PRR knockout models. Recently, viable renal cell-specific PRR knockout mice have been developed; these studies suggest that PRR in the nephron can modulate renal function via angiotensin II (ANG II)-dependent and -independent cell signaling pathways. In this mini-review, we highlight new developments in nephron PRR function in health and in pathophysiological conditions.

  8. Simulating calcium salt precipitation in the nephron using chemical speciation.

    PubMed

    Rodgers, Allen L; Allie-Hamdulay, Shameez; Jackson, Graham; Tiselius, Hans-Göran

    2011-08-01

    Theoretical modeling of urinary crystallization processes affords opportunities to create and investigate scenarios which would be extremely difficult or impossible to achieve in in vivo experiments. Researchers have previously hypothesized that calcium renal stone formation commences in the nephron. In the present study, concentrations of urinary components and pH ranges in different regions of the nephron were estimated from concentrations in blood combined with a knowledge of the renal handling of individual ions. These were used in the chemical speciation program JESS to determine the nature of the solution complexes in the different regions of the nephron and the saturation index (SI) of the stone-forming salts calcium oxalate (CaOx), brushite (Bru), hydroxyapatite (HAP) and octacalcium phosphate (OCP). The effect of independent precipitation of each of the latter on the SI values of other salts was also investigated. HAP was the only salt which was supersaturated throughout the nephron. All of the other salts were supersaturated only in the middle and distal regions of the collecting duct. Supersaturations were pH sensitive. When precipitation of CaOx, Bru and OCP was simulated in the distal part of the collecting duct, little or no effect on the SI values of the other stone forming salts was observed. However, simulation of HAP precipitation caused all other salts to become unsaturated. This suggests that if HAP precipitates, a pure stone comprising this component will ensue while if any of the other salts precipitates, a mixed CaOx/CaP stone will be formed. Application of Ostwald's Rule of Stages predicts that the mixed stone is likely to be CaOx and Bru. Our modelling demonstrates that precipitation of stone-forming salts in the nephron is highly dependent on the delicate nature of the chemical equilibria which prevail and which are themselves highly dependent on pH and component concentrations.

  9. Insulin binding sites in various segments of the rabbit nephron

    SciTech Connect

    Nakamura, R.; Emmanouel, D.S.; Katz, A.I.

    1983-07-01

    Insulin binds specifically to basolateral renal cortical membranes and modifies tubular electrolyte transport, but the target sites of this hormone in the nephron have not been identified. Using a microassay that permits measurement of hormone binding in discrete tubule segments we have determined the binding sites of /sup 125/I-insulin along the rabbit nephron. Assays were performed under conditions that minimize insulin degradation, and specific binding was measured as the difference between /sup 125/I-insulin bound in the presence or absence of excess (10(-5) M) unlabeled hormone. Insulin monoiodinated in position A14 was used in all assays. Specific insulin binding (attomol . cm-1 +/- SE) was highest in the distal convoluted tubule (180.5 +/- 15.0) and medullary thick ascending limb of Henle's loop (132.9 +/- 14.6), followed by the proximal convoluted and straight tubule. When expressed per milligram protein, insulin binding capacity was highest along the entire thick ascending limb (medullary and cortical portions) and the distal convoluted tubule, i.e., the ''diluting segment'' (congruent to 10(-13) mol . mg protein-1), and was lower (congruent to 4 X 10(-14) mol . mg protein-1), and remarkably similar, in all other nephron segments. Binding specificity was verified in competition studies with unlabeled insulin, insulin analogues (proinsulin and desoctapeptide insulin), and unrelated hormones (glucagon, 1-34 parathyroid hormone, prolactin, follicle-stimulating hormone). In addition, serum containing antiinsulin receptor antibody from two patients with type B insulin resistance syndrome markedly inhibited insulin binding to isolated tubules. Whether calculated per unit tubule length or protein content, insulin binding is highest in the thick ascending limb and the distal convoluted tubule, the same nephron sites where a regulatory role in sodium transport has been postulated for this hormone.

  10. Caudal migration and proliferation of renal progenitors regulates early nephron segment size in zebrafish

    PubMed Central

    Naylor, Richard W.; Dodd, Rachel C.; Davidson, Alan J.

    2016-01-01

    The nephron is the functional unit of the kidney and is divided into distinct proximal and distal segments. The factors determining nephron segment size are not fully understood. In zebrafish, the embryonic kidney has long been thought to differentiate in situ into two proximal tubule segments and two distal tubule segments (distal early; DE, and distal late; DL) with little involvement of cell movement. Here, we overturn this notion by performing lineage-labelling experiments that reveal extensive caudal movement of the proximal and DE segments and a concomitant compaction of the DL segment as it fuses with the cloaca. Laser-mediated severing of the tubule, such that the DE and DL are disconnected or that the DL and cloaca do not fuse, results in a reduction in tubule cell proliferation and significantly shortens the DE segment while the caudal movement of the DL is unaffected. These results suggest that the DL mechanically pulls the more proximal segments, thereby driving both their caudal extension and their proliferation. Together, these data provide new insights into early nephron morphogenesis and demonstrate the importance of cell movement and proliferation in determining initial nephron segment size. PMID:27759103

  11. Morphology and histochemistry of juvenile American alligator (Alligator mississippiensis) nephrons.

    PubMed

    Moore, Brandon C; Hyndman, Kelly A; Cox, Ashley; Lawler, Ashley; Mathavan, Ketan; Guillette, Louis J

    2009-10-01

    Here we present a detailed morphological description of the alligator (Alligator mississippiensis) kidney and nephron. We present a series of histological, histochemical, and immunohistochemical markers that clearly define the seven regions of the alligator nephron. The alligator kidney is composed of many paired (mirrored) lobules on each kidney (lobe). Single nephrons span the width of lobules three times. The fine structure of glomeruli, lying in rows spanning the height of the lobule, is resolved by periodic acid methionine silver (PAMS) and periodic acid Schiff's (PAS) histochemistry. Glomeruli are connected to the proximal tubule (PT) via a neck segment. The PT is alcian blue-negative, making it distinct from the distal tubule (DT), connecting segment (CS), and collecting duct (CD). The PT is clearly identifiable by a PAS-positive brush border membrane. The PT is connected to the DT via an intermediate segment (IS) that makes a 180 degrees turn to connect these tubules. PAMS-positive material is found in the lumens of the PT, IS, and DT. Also, PAMS-positive granules are found in the DT, CS, and CD. Immunolocalization of the Na(+), K(+)-ATPase to the basolateral membrane of the DT, CS, and CD suggests a role of this enzyme in driving primary and secondary transport processes in these segments, including bicarbonate transport into the lumen of the DT (leading to an alkaline urine). Through the techniques described here, we have identified a series of distinct markers to be used by pathologists, veterinarians, and researchers to easily identify alligator nephron segments. Anat Rec, 2009. (c) 2009 Wiley-Liss, Inc.

  12. Electrotonic vascular signal conduction and nephron synchronization.

    PubMed

    Marsh, Donald J; Toma, Ildiko; Sosnovtseva, Olga V; Peti-Peterdi, Janos; Holstein-Rathlou, Niels-Henrik

    2009-04-01

    Tubuloglomerular feedback (TGF) and the myogenic mechanism control afferent arteriolar diameter in each nephron and regulate blood flow. Both mechanisms generate self-sustained oscillations, the oscillations interact, TGF modulates the frequency and amplitude of the myogenic oscillation, and the oscillations synchronize; a 5:1 frequency ratio is the most frequent. TGF oscillations synchronize in nephron pairs supplied from a common cortical radial artery, as do myogenic oscillations. We propose that electrotonic vascular signal propagation from one juxtaglomerular apparatus interacts with similar signals from other nephrons to produce synchronization. We tested this idea in tubular-vascular preparations from mice. Vascular smooth muscle cells were loaded with a fluorescent voltage-sensitive dye; fluorescence intensity was measured with confocal microscopy. Perfusion of the thick ascending limb activated TGF and depolarized afferent arteriolar smooth muscle cells. The depolarization spread to the cortical radial artery and other afferent arterioles and declined with distance from the perfused juxtaglomerular apparatus, consistent with electrotonic vascular signal propagation. With a mathematical model of two coupled nephrons, we estimated the conductance of nephron coupling by fitting simulated vessel diameters to experimental data. With this value, we simulated nephron pairs to test for synchronization. In single-nephron simulations, the frequency of the TGF oscillation varied with nephron length. Coupling nephrons of different lengths forced TGF frequencies of both pair members to converge to a common value. The myogenic oscillations also synchronized, and the synchronization between the TGF and the myogenic oscillations showed an increased stability against parameter perturbations. Electronic vascular signal propagation is a plausible mechanism for nephron synchronization. Coupling increased the stability of the various oscillations.

  13. Prorenin receptor is critical for nephron progenitors.

    PubMed

    Song, Renfang; Preston, Graeme; Kidd, Laura; Bushnell, Daniel; Sims-Lucas, Sunder; Bates, Carlton M; Yosypiv, Ihor V

    2016-01-15

    Deficient nephrogenesis is the major factor contributing to renal hypoplasia defined as abnormally small kidneys. Nephron induction during kidney development is driven by reciprocal interactions between progenitor cells of the cap mesenchyme (CM) and the ureteric bud (UB). The prorenin receptor (PRR) is a receptor for renin and prorenin, and an accessory subunit of the vacuolar proton pump H(+)-ATPase. Global loss of PRR is lethal in mice and PRR mutations are associated with a high blood pressure, left ventricular hypertrophy and X-linked mental retardation in humans. To circumvent lethality of the ubiquitous PRR mutation in mice and to determine the potential role of the PRR in nephrogenesis, we generated a mouse model with a conditional deletion of the PRR in Six2(+) nephron progenitors and their epithelial derivatives (Six2(PRR-/-)). Targeted ablation of PRR in Six2(+) nephron progenitors caused a marked decrease in the number of developing nephrons, small cystic kidneys and podocyte foot process effacement at birth, and early postnatal death. Reduced congenital nephron endowment resulted from premature depletion of nephron progenitor cell population due to impaired progenitor cell proliferation and loss of normal molecular inductive response to canonical Wnt/β-catenin signaling within the metanephric mesenchyme. At 2 months of age, heterozygous Six2(PRR+/-) mice exhibited focal glomerulosclerosis, decreased kidney function and massive proteinuria. Collectively, these findings demonstrate a cell-autonomous requirement for the PRR within nephron progenitors for progenitor maintenance, progression of nephrogenesis, normal kidney development and function.

  14. Hepcidin regulates intrarenal iron handling at the distal nephron.

    PubMed

    Moulouel, Boualem; Houamel, Dounia; Delaby, Constance; Tchernitchko, Dimitri; Vaulont, Sophie; Letteron, Philippe; Thibaudeau, Olivier; Puy, Hervé; Gouya, Laurent; Beaumont, Carole; Karim, Zoubida

    2013-10-01

    Hepcidin, the key regulatory hormone of iron homeostasis, and iron carriers such as transferrin receptor1 (TFR1), divalent metal transporter1 (DMT1), and ferroportin (FPN) are expressed in kidney. Whether hepcidin plays an intrinsic role in the regulation of renal iron transport is unknown. Here, we analyzed the renal handling of iron in hemochromatosis Hepc(-/-) and Hjv(-/-) mouse models, as well as in phenylhydrazine (PHZ)-treated mice. We found a marked medullary iron deposition in the kidneys of Hepc(-/-) mice, and iron leak in the urine. The kidneys of Hepc(-/-) mice exhibited a concomitant decrease in TFR1 and increase in ferritin and FPN expression. Increased FPN abundance was restricted to the thick ascending limb (TAL). DMT1 protein remained unaffected despite a significant decrease of its mRNA level, suggesting that DMT1 protein is stabilized in the absence of hepcidin. Treatment of kidney sections from Hepc(-/-) mice with hepcidin decreased DMT1 protein, an effect confirmed in renal cell lines where hepcidin markedly decreased (55)Fe transport. In the kidneys of Hjv(-/-) mice exhibiting low hepcidin expression, the iron overload was similar to that in the kidneys of Hepc(-/-) mice. However, in PHZ mice, iron accumulation resulting from hemoglobin leak was detected in the proximal tubule. Thus, kidneys exhibit a tissue-specific handling of iron that depends on the extra iron source. Hepcidin may control the expression of iron transporters to prevent renal iron overload.

  15. A molecular map of G protein alpha chains in microdissected rat nephron segments.

    PubMed Central

    Senkfor, S I; Johnson, G L; Berl, T

    1993-01-01

    Membrane-associated guanine nucleotide binding proteins regulate many receptor-mediated signals. Heterogeneity of biochemical and functional properties in nephron segments could be due to differences in G protein expression. To ascertain whether such heterogeneity of G proteins is present in various nephron segments, this study examines the distribution and relative abundance of G protein alpha chains in microdissected medullary thick ascending limb, cortical collecting tubules, outer medullary collecting tubules, proximal inner medullary tubules, and distal inner medullary tubules. Reverse transcription and polymerase chain reactions were employed using oligonucleotides encoding highly conserved regions of all known alpha chains. The cDNA was sequenced for alpha chain identification. The alpha i2 versus alpha s distribution was different in the outer medullary collecting tubules, when compared with the medullary thick ascending limb (P < 0.001) or the cortical collecting tubule, the proximal inner medullary tubules, and the distal inner medullary tubules (P < 0.05). These latter four segments did not significantly differ from each other. A similar analysis was applied to the frequently used line of kidney cells, LLC-PK1, whose exact cellular origin remains unclear. Interestingly, we detected both alpha i2 and alpha i3, while only alpha i2 was detected in the rat distal nephron. No alpha o or alpha z reverse transcription PCR products were detected. In contrast alpha 11 and alpha 14 members of the more recently described alpha q family were detected in the outer medullary collecting tubules and the proximal inner medullary tubules, respectively. We conclude that the majority of nephron segments have a relatively constant distribution of G protein alpha chains. Images PMID:8349818

  16. Prostaglandin signaling regulates nephron segment patterning of renal progenitors during zebrafish kidney development

    PubMed Central

    Poureetezadi, Shahram Jevin; Cheng, Christina N; Chambers, Joseph M; Drummond, Bridgette E; Wingert, Rebecca A

    2016-01-01

    Kidney formation involves patterning events that induce renal progenitors to form nephrons with an intricate composition of multiple segments. Here, we performed a chemical genetic screen using zebrafish and discovered that prostaglandins, lipid mediators involved in many physiological functions, influenced pronephros segmentation. Modulating levels of prostaglandin E2 (PGE2) or PGB2 restricted distal segment formation and expanded a proximal segment lineage. Perturbation of prostaglandin synthesis by manipulating Cox1 or Cox2 activity altered distal segment formation and was rescued by exogenous PGE2. Disruption of the PGE2 receptors Ptger2a and Ptger4a similarly affected the distal segments. Further, changes in Cox activity or PGE2 levels affected expression of the transcription factors irx3b and sim1a that mitigate pronephros segment patterning. These findings show for the first time that PGE2 is a regulator of nephron formation in the zebrafish embryonic kidney, thus revealing that prostaglandin signaling may have implications for renal birth defects and other diseases. DOI: http://dx.doi.org/10.7554/eLife.17551.001 PMID:27996936

  17. Nephron induction revisited: from caps to condensates.

    PubMed

    Sariola, Hannu

    2002-01-01

    Conversion of mesenchyme to epithelium in the metanephric kidney is clearly a multimolecular, multistep and partly redundant process. The present short review focuses on a neglected morphological aspect of kidney differentiation: the development of two transitory mesenchymal condensations that precede epithelial differentiation of nephrons. The first appearing condensate covers the tips of the collecting ducts and is termed a cap condensate. In the early kidney rudiment this structure has been referred to as a primary or early condensate. A few cells of the cap condensate (maybe only four to six cells), situated at the lateral edge of the cap, start proliferating rapidly and form a pretubular aggregate (or pretubular condensate), which converts to secretory nephron epithelia and finally segregates to different tubule segments. Throughout nephrogenesis, the cap condensates and pretubular aggregates are clearly distinguishable structures that show only partly overlapping gene expression profiles. Apart from being the source for the pretubular aggregates, the role of the cap condensate is unknown. It is now proposed that the cap regulates ureteric branching morphogenesis.

  18. Repair after nephron ablation reveals limitations of neonatal neonephrogenesis

    PubMed Central

    Tögel, Florian; Freedman, Benjamin S.; Iatrino, Rossella; Grinstein, Mor; Bonventre, Joseph V.

    2017-01-01

    The neonatal mouse kidney retains nephron progenitor cells in a nephrogenic zone for 3 days after birth. We evaluated whether de novo nephrogenesis can be induced postnatally beyond 3 days. Given the long-term implications of nephron number for kidney health, it would be useful to enhance nephrogenesis in the neonate. We induced nephron reduction by cryoinjury with or without contralateral nephrectomy during the neonatal period or after 1 week of age. There was no detectable compensatory de novo nephrogenesis, as determined by glomerular counting and lineage tracing. Contralateral nephrectomy resulted in additional adaptive healing, with little or no fibrosis, but did not also stimulate de novo nephrogenesis. In contrast, injury initiated at 1 week of age led to healing with fibrosis. Thus, despite the presence of progenitor cells and ongoing nephron maturation in the newborn mouse kidney, de novo nephrogenesis is not inducible by acute nephron reduction. This indicates that additional nephron progenitors cannot be recruited after birth despite partial renal ablation providing a reparative stimulus and suggests that nephron number in the mouse is predetermined at birth. PMID:28138555

  19. DISTAL MYOPATHIES

    PubMed Central

    Dimachkie, Mazen M.; Barohn, Richard J.

    2014-01-01

    Over a century ago, Gowers described two young patients in whom distal muscles weakness involved the hand, foot, sternocleidomastoid, and facial muscles in the other case the shoulder and distal leg musculature. Soon after, , similar distal myopathy cases were reported whereby the absence of sensory symptoms and of pathologic changes in the peripheral nerves and spinal cord at postmortem examination allowed differentiation from Charcot-Marie-Tooth disease. In 1951, Welander described autosomal dominant (AD) distal arm myopathy in a large Scandanavian cohort. Since then the number of well-characterized distal myopathies has continued to grow such that the distal myopathies have formed a clinically and genetically heterogeneous group of disorders. Affected kindred commonly manifest weakness that is limited to foot and toe muscles even in advanced stages of the disease, with variable mild proximal leg, distal arm, neck and laryngeal muscle involvement in selected individuals. An interesting consequence of the molecular characterization of the distal myopathies has been the recognition that mutation in a single gene can lead to more than one clinical disorder. For example, Myoshi myopathy (MM) and limb girdle muscular dystrophy (LGMD) type 2B are allelic disorders due to defects in the gene that encodes dysferlin. The six well described distal myopathy syndromes are shown in Table 1. Table 2 lists advances in our understanding of the myofibrillar myopathy group and Table 3 includes more recently delineated and less common distal myopathies. In the same manner, the first section of this review pertains to the more traditional six distal myopathies followed by discussion of the myofibrillar myopathies. In the third section, we review other clinically and genetically distinctive distal myopathy syndromes usually based upon single or smaller family cohorts. The fourth section considers other neuromuscular disorders that are important to recognize as they display prominent

  20. A nephron-based model of the kidneys for macro-to-micro α-particle dosimetry.

    PubMed

    Hobbs, Robert F; Song, Hong; Huso, David L; Sundel, Margaret H; Sgouros, George

    2012-07-07

    Targeted α-particle therapy is a promising treatment modality for cancer. Due to the short path-length of α-particles, the potential efficacy and toxicity of these agents is best evaluated by microscale dosimetry calculations instead of whole-organ, absorbed fraction-based dosimetry. Yet time-integrated activity (TIA), the necessary input for dosimetry, can still only be quantified reliably at the organ or macroscopic level. We describe a nephron- and cellular-based kidney dosimetry model for α-particle radiopharmaceutical therapy, more suited to the short range and high linear energy transfer of α-particle emitters, which takes as input kidney or cortex TIA and through a macro to micro model-based methodology assigns TIA to micro-level kidney substructures. We apply a geometrical model to provide nephron-level S-values for a range of isotopes allowing for pre-clinical and clinical applications according to the medical internal radiation dosimetry (MIRD) schema. We assume that the relationship between whole-organ TIA and TIA apportioned to microscale substructures as measured in an appropriate pre-clinical mammalian model also applies to the human. In both, the pre-clinical and the human model, microscale substructures are described as a collection of simple geometrical shapes akin to those used in the Cristy-Eckerman phantoms for normal organs. Anatomical parameters are taken from the literature for a human model, while murine parameters are measured ex vivo. The murine histological slides also provide the data for volume of occupancy of the different compartments of the nephron in the kidney: glomerulus versus proximal tubule versus distal tubule. Monte Carlo simulations are run with activity placed in the different nephron compartments for several α-particle emitters currently under investigation in radiopharmaceutical therapy. The S-values were calculated for the α-emitters and their descendants between the different nephron compartments for both the

  1. A nephron-based model of the kidneys for macro-to-micro α-particle dosimetry

    PubMed Central

    Hobbs, Robert F; Song, Hong; Huso, David L; Sundel, Margaret; Sgouros, George

    2013-01-01

    Objective Targeted α-particle therapy is a promising treatment modality for cancer. Due to the short path-length of α-particles, the potential efficacy and toxicity of these agents is best evaluated by microscale dosimetry calculations instead of whole-organ, absorbed fraction –based dosimetry. Yet time-integrated activity (TIA), the necessary input for dosimetry, can still only be quantified reliably at the organ or macroscopic level. We describe a nephron- and cellular-based kidney dosimetry model for α-particle radiopharmaceutical therapy, more suited to the short range and high linear energy transfer of α-particle emitters, which takes as input kidney or cortex TIA and through a macro to micro model-based methodology assigns TIA to micro-level kidney substructures. We apply the model to provide nephron-level S-values for a range of isotopes allowing for pre-clinical and clinical applications according to the medical internal radiation dosimetry (MIRD) schema. Methods We assume that the relationship between whole-organ TIA and TIA apportioned to microscale substructures as measured in an appropriate pre-clinical mammalian model also applies to the human. In both, the pre-clinical and the human model, microscale substructures are described as a collection of simple geometrical shapes akin go those used in the Cristy-Eckermann phantoms for normal organs. Anatomical parameters are taken from the literature for a human model, while murine parameters are measured, ex vivo. The murine histological slides also provide the data for volume of occupancy of the different compartments of the nephron in the kidney: glomerulus vs. proximal tubule vs. distal tubule. Monte Carlo simulations are run with activity placed in the different nephron compartments for several α-particle emitters currently under investigation in radiopharmaceutical therapy. Results The S-values were calculated for the α-emitters and their descendants between the different nephron compartments

  2. A nephron-based model of the kidneys for macro-to-micro α-particle dosimetry

    NASA Astrophysics Data System (ADS)

    Hobbs, Robert F.; Song, Hong; Huso, David L.; Sundel, Margaret H.; Sgouros, George

    2012-07-01

    Targeted α-particle therapy is a promising treatment modality for cancer. Due to the short path-length of α-particles, the potential efficacy and toxicity of these agents is best evaluated by microscale dosimetry calculations instead of whole-organ, absorbed fraction-based dosimetry. Yet time-integrated activity (TIA), the necessary input for dosimetry, can still only be quantified reliably at the organ or macroscopic level. We describe a nephron- and cellular-based kidney dosimetry model for α-particle radiopharmaceutical therapy, more suited to the short range and high linear energy transfer of α-particle emitters, which takes as input kidney or cortex TIA and through a macro to micro model-based methodology assigns TIA to micro-level kidney substructures. We apply a geometrical model to provide nephron-level S-values for a range of isotopes allowing for pre-clinical and clinical applications according to the medical internal radiation dosimetry (MIRD) schema. We assume that the relationship between whole-organ TIA and TIA apportioned to microscale substructures as measured in an appropriate pre-clinical mammalian model also applies to the human. In both, the pre-clinical and the human model, microscale substructures are described as a collection of simple geometrical shapes akin to those used in the Cristy-Eckerman phantoms for normal organs. Anatomical parameters are taken from the literature for a human model, while murine parameters are measured ex vivo. The murine histological slides also provide the data for volume of occupancy of the different compartments of the nephron in the kidney: glomerulus versus proximal tubule versus distal tubule. Monte Carlo simulations are run with activity placed in the different nephron compartments for several α-particle emitters currently under investigation in radiopharmaceutical therapy. The S-values were calculated for the α-emitters and their descendants between the different nephron compartments for both the

  3. The Fate of Nephrons in Congenital Obstructive Nephropathy: Adult Recovery is Limited by Nephron Number Despite Early Release of Obstruction

    PubMed Central

    Sergio, Maria; Galarreta, Carolina I.; Thornhill, Barbara A.; Forbes, Michael S.; Chevalier, Robert L.

    2015-01-01

    Purpose Urinary tract obstruction and reduced nephron number often occur together as a result of maldevelopment of kidneys and urinary tract. We wished to determine the role of nephron number on the adaptation of remaining nephrons of mice subjected to neonatal partial unilateral ureteral obstruction (UUO) and followed through adulthood. Materials and Methods Wild-type (WT) and Os/+ mice (with 50% fewer nephrons) were subjected to sham operation or partial UUO in the first 2 days of life. Additional mice underwent release of UUO at 7 days. All kidneys were harvested at 3 weeks (weaning) or 6 weeks (adulthood). Glomerular number and area, glomerulotubular junction integrity, proximal tubular volume fraction, and interstitial fibrosis were measured by histomorphometry. Results In the obstructed kidney, UUO caused additional nephron loss in Os/+ but not WT mice. Glomerular growth from 3 to 6 weeks was impaired by ipsilateral UUO and was not preserved by release in WT or Os/+. Proximal tubular growth was impaired and interstitial collagen was increased by ipsilateral UUO in all mice. These were attenuated by release of UUO in WT mice, but were not restored in Os/+ mice. UUO increased interstitial collagen in the contralateral kidney; release of UUO enhanced tubular growth and reduced interstitial collagen. Conclusions We conclude that UUO in early postnatal development impairs adaptation to reduced nephron number and induces additional nephron loss despite release of obstruction. Premature and low birth weight infants with congenital obstructive nephropathy are likely at increased risk for progression of chronic kidney disease. PMID:25912494

  4. Three-dimensional reconstruction of the rat nephron.

    PubMed

    Christensen, Erik I; Grann, Birgitte; Kristoffersen, Inger B; Skriver, Elisabeth; Thomsen, Jesper S; Andreasen, Arne

    2014-03-15

    This study gives a three-dimensional (3D) structural analysis of rat nephrons and their connections to collecting ducts. Approximately 4,500 2.5-μm-thick serial sections from the renal surface to the papillary tip were obtained from each of 3 kidneys of Wistar rats. Digital images were recorded and aligned into three image stacks and traced from image to image. Short-loop nephrons (SLNs), long-loop nephrons (LLNs), and collecting ducts (CDs) were reconstructed in 3D. We identified a well-defined boundary between the outer stripe and the inner stripe of the outer medulla corresponding to the transition of descending thick limbs to descending thin limbs and between the inner stripe and the inner medulla, i.e., the transition of ascending thin limbs into ascending thick limbs of LLNs. In all nephrons, a mosaic pattern of proximal tubule (PT) cells and descending thin limb (DTL) cells was observed at the transition between the PT and the DTL. The course of the LLNs revealed tortuous proximal "straight" tubules and winding of the DTLs within the outer half of the inner stripe. The localization of loop bends of SLNs in the inner stripe of the outer medulla and the bends of LLNs in the inner medulla reflected the localization of their glomeruli; i.e., the deeper the glomerulus, the deeper the bend. Each CD drained approximately three to six nephrons with a different pattern than previously established in mice. This information will provide a basis for evaluation of structural changes within nephrons as a result of physiological or pharmaceutical intervention.

  5. Maternal Fat Feeding Augments Offspring Nephron Endowment in Mice

    PubMed Central

    Hokke, Stacey; Puelles, Victor G.; Armitage, James A.; Fong, Karen; Bertram, John F.; Cullen-McEwen, Luise A.

    2016-01-01

    Increasing consumption of a high fat 'Western' diet has led to a growing number of pregnancies complicated by maternal obesity. Maternal overnutrition and obesity have health implications for offspring, yet little is known about their effects on offspring kidney development and renal function. Female C57Bl6 mice were fed a high fat diet (HFD, 21% fat) or matched normal fat diet (NFD, 6% fat) for 6 weeks prior to pregnancy and throughout gestation and lactation. HFD dams were overweight and glucose intolerant prior to mating but not in late gestation. Offspring of NFD and HFD dams had similar body weights at embryonic day (E)15.5, E18.5 and at postnatal day (PN)21. HFD offspring had normal ureteric tree development and nephron number at E15.5. However, using unbiased stereology, kidneys of HFD offspring were found to have 20–25% more nephrons than offspring of NFD dams at E18.5 and PN21. Offspring of HFD dams with body weight and glucose profiles similar to NFD dams prior to pregnancy also had an elevated nephron endowment. At 9 months of age, adult offspring of HFD dams displayed mild fasting hyperglycaemia but similar body weights to NFD offspring. Renal function and morphology, measured by transcutaneous clearance of FITC-sinistrin and stereology respectively, were normal. This study demonstrates that maternal fat feeding augments offspring nephron endowment with no long-term consequences for offspring renal health. Future studies assessing the effects of a chronic stressor on adult mice with augmented nephron number are warranted, as are studies investigating the molecular mechanisms that result in high nephron endowment. PMID:27547968

  6. Tubuloglomerular Feedback and Single Nephron Function after Converting Enzyme Inhibition in the Rat

    PubMed Central

    Ploth, David W.; Rudulph, James; Lagrange, Ronald; Navar, L. Gabriel

    1979-01-01

    Experiments were done in normal rats to assess kidney, single nephron, and tubuloglomerular feedback responses during renin-angiotensin blockade with the converting enzyme inhibitor (CEI) SQ 20881 (E. R. Squibb & Sons, Princeton, N. Y.) (3 mg/kg, per h). Converting enzyme inhibition was documented by complete blockade of vascular responses to infusions of angiotensin I (600 ng/kg). Control plasma renin activity was 12.5±2.7 ng angiotensin I/ml per h (mean±SEM) and increased sevenfold with CEI (n = 7). There were parallel increases in glomerular filtration rate from 1.08±0.05 to 1.26±0.05 ml/min and renal blood flow from 6.7±0.4 to 7.5±0.5 ml/min. During CEI infusion absolute and fractional sodium excretion were increased 10-fold. Proximal tubule and peritubular capillary pressures were unchanged. Single nephron glomerular filtration rate (SNGFR) was measured from both proximal and distal tubule collections; SNGFR based only on distal collections was significantly increased by CEI. A significant difference was observed between SNGFR values measured from proximal and distal tubule sites (6.0±1.6 nl/min) and this difference remained unchanged after CEI administration. Slight decreases in fractional absorption were suggested at micropuncture sites beyond the late proximal tubule, whereas early distal tubule flow rate was augmented by CEI. Tubuloglomerular feedback activity was assessed by measuring changes in proximal tubule stop-flow pressure (SFP) or SNGFR in response to alterations in orthograde microperfusion rate from late proximal tubule sites. During control periods, SFP was decreased 11.2±0.4 mm Hg when the perfusion rate was increased to 40 nl/min; during infusion of CEI, the same increase in perfusion rate resulted in a SFP decrement of 6.7±0.5 mm Hg (P<.001). When late proximal tubule perfusion rate was increased from 0 to 30 nl/min, SNGFR was decreased by 15.0±1.2 nl/min during control conditions, and by 11.3±1.3 nl/min during CEI infusion

  7. The postobstructive kidney. Observations on nephron function after the relief of 24 hr of ureteral ligation in the dog

    PubMed Central

    Bercovitch, D. Danny; Kasen, Leonard; Blann, Laurence; Levitt, Marvin F.

    1971-01-01

    After the relief of 24 hr of complete unilateral ureteral obstruction in the dog, the experimental kidney is characterized by a decrease in filtration rate and an increase in fractional and often absolute excretion of sodium before and after the administration of mannitol. In the hydrated state, the failure to conserve sodium is associated with increases in fractional free water clearance and fractional sodium supply to water-freeing sites signifying that the augmented sodium excretion is derived from a proximal source. In the hydropenic state there is decreased fractional free water reabsorption, and sometimes free water excretion, in the postobstructive kidney. An early plateau in free water reabsorption is associated with an increased fractional excretion of sodium. These findings are attributed to the early development of distal nephron impermeability to water as a result of enhanced distal tubular supply and transport of sodium. There is a decrease in maximal tubular reabsorptive capacity (Tm) of glucose in the post-obstructive kidney which is, however, less marked than the decrease in filtration rate. The fall in filtration rate is to some extent likely due to a dropping out of nephrons from the circulation while the remaining nephrons are hypoperfused. The magnitude of the sodium reabsorptive defect is markedly exaggerated as the concentration of nonreabsorbable solute (mannitol) in the glomerular perfusate is increased. It is concluded that the postobstructive increase in sodium excretion during mannitol administration is in part due to a limit in the capacity to reabsorb sodium against a concentration gradient in the proximal tubule. PMID:5552413

  8. Contribution of individual superficial nephron segments to ammonium handling in chronic metabolic acidosis in the rat. Evidence for ammonia disequilibrium in the renal cortex.

    PubMed Central

    Simon, E; Martin, D; Buerkert, J

    1985-01-01

    Ammonia entry along surface nephron segments of rats was studied with micropuncture techniques under control and chronic metabolic acidosis conditions. Tubule fluid was collected successively from sites at the end and beginning of the distal tubule and at the end of the proximal tubule of the same nephron. During chronic metabolic acidosis, ammonium excretion doubled. As anticipated, the ammonium concentration (TFNH+4) was significantly higher in proximal tubule fluid during acidosis, and ammonium delivery to end proximal sites increased from 19.4 +/- 2.3 to 34.0 +/- 3.2 pmol/min (P less than 0.001). Although chronic acidosis did not affect TFNH+4 at the beginning of the distal tubule, ammonium delivery to the end of the distal tubule increased from 5.72 +/- 0.97 to 9.88 +/- 0.97 pmol/min. In both control and acidotic groups ammonium delivery was lower (P less than 0.001) to end distal sites than to end proximal sites, indicating net loss in the intervening segment. This loss was greater during chronic metabolic acidosis (23.9 +/- 3.3 vs. 13.6 +/- 2.0 pmol/min in controls, P less than 0.025). In both groups net entry of ammonia, in similar amounts, occurred along the distal tubule (P less than 0.05). In situ pH averaged 6.80 +/- 0.05 at end proximal tubule sites and fell to 6.54 +/- 0.08 at the beginning of the distal tubule (P less than 0.005). Chronic metabolic acidosis did not affect these measurements. The calculated free ammonia at the end of the proximal tubule rose from 9.3 +/- 2.2 to 21 +/- 9 microM (P less than 0.005) during chronic metabolic acidosis, and was also higher at beginning distal sites during acidosis (8.8 +/- 2.4 vs. 2.7 +/- 0.7 microM in controls, P less than 0.05). In both groups ammonia values for the beginning distal tubule fluid were lower than for end proximal tubule fluid. Thus, loss of ammonium in the loop segment is enhanced by chronic metabolic acidosis. Distal entry of ammonia is markedly less than along the proximal tubule and does

  9. Differential expression of claudin tight junction proteins in the human cortical nephron

    PubMed Central

    Kirk, Adam; Campbell, Sara; Bass, Paul; Mason, Juan; Collins, Jane

    2010-01-01

    Background. In renal tubules, paracellular permeability is tightly controlled to facilitate solute absorption and urinary concentration and is regulated by tight junctions, which incorporate claudin proteins. There is very limited information confirming the localization of these proteins in the human renal cortex. Most data is inferred from mouse, bovine and rabbit studies and differences exist between mouse and other species. Methods. A survey of claudin staining was performed on human kidney cortex embedded in glycolmethacrylate resin to enhance tissue morphology and facilitate the cutting of 2 µm serial sections. Results. Claudin-2, -10 and -11 antibodies labelled renal tubular epithelial cells, correlating with Lotus tetragonolobus and N-cadherin positive proximal tubules. Claudin-3, -10, -11 and -16 antibodies strongly stained a population of tubules that were positive for Tamm Horsfall protein on adjacent sections, confirming expression in the thick ascending limb of the Loop of Henle. Claudin-3, -4 and -8 antibodies reacted with tubules that correlated with the distal nephron markers, E-cadherin, epithelial membrane antigen and Dolichos biflorus and claudin-3, -4, -7 and -8 with the distal tubule marker, calbindin, and the collecting duct marker, aquaporin-2. Claudin-14 was localized in distal convoluted tubules, correlating positively with calbindin but negatively with aquaporin-2, whereas claudin-1 staining was identified in the parietal epithelium of Bowman's capsule, distal convoluted tubule and collecting duct. Cellular and tight junction localization of claudin staining in renal tubules was heterogeneous and is discussed. Conclusions. Complex variation in the expression of human claudins likely determines paracellular permeability in the kidney. Altered claudin expression may influence pathologies involving abnormalities of absorption. PMID:20124215

  10. Development of a Manipulative for Nephron Physiology Education

    ERIC Educational Resources Information Center

    Giffen, Zane C.; Carvalho, Helena

    2015-01-01

    Some physiological concepts, such as physiology of filtration and absorption in the different nephron segments, are so detailed that they can be a challenge to be memorized. This article describes an exercise that solidifies learning as students manipulate, using paper models, "transporters" and "electrolytes" in the…

  11. A Shunt Model of the Inner Medullary Nephron with Pre-Bend Transitions

    NASA Astrophysics Data System (ADS)

    Gonzalez, M. T.; Hegarty, A. F.; Thomas, S. R.

    2009-09-01

    Mathematical models of the renal medulla face the problem of representing water and solute transfer among tens of thousands of nephrons and blood vessels of various lengths, arranged in countercurrent fashion. Published models fall into two broad categories with respect to this issue: multi-nephron models, which explicitly represent a large number of individual nephrons, or lumped models with virtual shunts that represent the turning back of nephrons and vessels at varying depths. Shunt models have the advantage of a compact description and relatively rapid execution time but are ill-suited to faithfully represent features such as prebend transitions of epithelial permeabilities in nephrons of different lengths. A new shunt model approach that can accommodate pre-bend transitions of nephrons at all medullary depths is presented in this work together with the results of simulation of predicted flows and concentrations.

  12. Modifications of the genital kidney proximal and distal tubules for sperm transport in Notophthalmus viridescens (Amphibia, Urodela, Salamandridae).

    PubMed

    Nicholson, Abbigail E; Siegel, Dustin S

    2014-08-01

    Male salamanders use nephrons from the genital kidney to transport sperm from the testicular lobules to the Wolffian duct. The microstructure of the epithelia of the genital kidney proximal tubule and distal tubule was studied over 1 year in a population of Notophthalmus viridescens from Crawford and Pike counties in central Missouri. Through ultrastructural analysis, we were able to support the hypothesis that the genital kidney nephrons are modified to aid in the transportation of sperm. A lack of folding of the basal plasma membrane, in both the genital kidney proximal and distal tubules when compared to the pelvic kidney proximal and distal tubules, reduces the surface area and thus likely decreases the efficiency of reabsorption in these nephron regions of the genital kidney. Ciliated epithelial cells are also present along the entire length of the genital kidney proximal tubule, but are lacking in the epithelium of the pelvic kidney proximal tubule. The exact function of these cilia remains unknown, but they may aid in mixing of seminal fluids or the transportation of immature sperm through the genital kidney nephrons. Ultrastructural analysis of proximal and distal tubules of the genital kidney revealed no seasonal variation in cellular activity and no mass production of seminal fluids throughout the reproductive cycle. Thus, we failed to support the hypothesis that the cellular activity of the epithelia lining the genital kidney nephrons is correlated to specific events in the reproductive cycle. The cytoplasmic contents and overall structure of the genital and pelvic kidney epithelial cells were similar to recent observations in Ambystoma maculatum, with the absence of abundant dense bodies apically in the epithelial cells lining the genital kidney distal tubule.

  13. Distal splenorenal shunt

    MedlinePlus

    ... shunt; Cirrhosis - distal splenorenal; Liver failure - distal splenorenal; Portal vein pressure - distal splenorenal shunt ... vein from your spleen is removed from the portal vein. The vein is then attached to the ...

  14. NEW NEPHRON DEVELOPMENT IN FISH FROM POLLUTED WATERS: A POSSIBLE BIOMARKER

    EPA Science Inventory

    Recent evidence has shown that fish have the ability to develop new nephrons following renal injury. This study evaluated the usefulness of quantifying developing nephrons in mature fish as an ecotoxicological assessment tool. Histological sections of kidney were prepared from At...

  15. Nephron Number, Hypertension, and CKD: Physiological and Genetic Insight from Humans and Animal Models.

    PubMed

    Wang, Xuexiang; Garrett, Michael R

    2017-01-27

    The kidneys play a vital role in the excretion of waste products and the regulation of electrolytes, maintenance of acid-base balance, regulation of blood pressure, and production of several hormones. Any alteration in the structure of the nephron (basic functional unit of the kidney) can have a major impact on the kidney's ability to work efficiently. Progressive decline in kidney function can lead to serious illness and ultimately death if not treated by dialysis or transplantation. While there have been numerous studies that implicate lower nephron numbers as being an important factor in influencing susceptibility to develop hypertension and chronic kidney disease, a direct association has been difficult to establish because of three main limitations: (1) the large variation in nephron number observed in the human population; (2) no established reliable non-invasive methods to determine nephron complement; and (3) to-date, nephron measurements have been done after death which doesn't adequately account for potential loss of nephrons with age or disease. In this review, we will provide an overview of kidney structure/function, discuss the current literature for both humans and other species linking nephron deficiency and cardio-renal complications, as well as, describe the major molecular signaling factors involved in nephrogenesis that modulate variation in nephron number. As more detailed knowledge about the molecular determinants of nephron development and the role of nephron endowment in the cardio-renal system is obtained, it will hopefully provide clinicians the ability to accurately identify people at risk to develop CKD/hypertension and lead to a shift in patient care from disease treatment to prevention.

  16. Towards Automated Three-Dimensional Tracking of Nephrons through Stacked Histological Image Sets

    PubMed Central

    Bhikha, Charita; Andreasen, Arne; Christensen, Erik I.; Letts, Robyn F. R.; Pantanowitz, Adam; Rubin, David M.; Thomsen, Jesper S.; Zhai, Xiao-Yue

    2015-01-01

    An automated approach for tracking individual nephrons through three-dimensional histological image sets of mouse and rat kidneys is presented. In a previous study, the available images were tracked manually through the image sets in order to explore renal microarchitecture. The purpose of the current research is to reduce the time and effort required to manually trace nephrons by creating an automated, intelligent system as a standard tool for such datasets. The algorithm is robust enough to isolate closely packed nephrons and track their convoluted paths despite a number of nonideal, interfering conditions such as local image distortions, artefacts, and interstitial tissue interference. The system comprises image preprocessing, feature extraction, and a custom graph-based tracking algorithm, which is validated by a rule base and a machine learning algorithm. A study of a selection of automatically tracked nephrons, when compared with manual tracking, yields a 95% tracking accuracy for structures in the cortex, while those in the medulla have lower accuracy due to narrower diameter and higher density. Limited manual intervention is introduced to improve tracking, enabling full nephron paths to be obtained with an average of 17 manual corrections per mouse nephron and 58 manual corrections per rat nephron. PMID:26170896

  17. Differential regulation of mouse and human nephron progenitors by the Six family of transcriptional regulators

    PubMed Central

    O'Brien, Lori L.; Guo, Qiuyu; Lee, YoungJin; Tran, Tracy; Benazet, Jean-Denis; Whitney, Peter H.; Valouev, Anton; McMahon, Andrew P.

    2016-01-01

    Nephron endowment is determined by the self-renewal and induction of a nephron progenitor pool established at the onset of kidney development. In the mouse, the related transcriptional regulators Six1 and Six2 play non-overlapping roles in nephron progenitors. Transient Six1 activity prefigures, and is essential for, active nephrogenesis. By contrast, Six2 maintains later progenitor self-renewal from the onset of nephrogenesis. We compared the regulatory actions of Six2 in mouse and human nephron progenitors by chromatin immunoprecipitation followed by DNA sequencing (ChIP-seq). Surprisingly, SIX1 was identified as a SIX2 target unique to the human nephron progenitors. Furthermore, RNA-seq and immunostaining revealed overlapping SIX1 and SIX2 activity in 16 week human fetal nephron progenitors. Comparative bioinformatic analysis of human SIX1 and SIX2 ChIP-seq showed each factor targeted a similar set of cis-regulatory modules binding an identical target recognition motif. In contrast to the mouse where Six2 binds its own enhancers but does not interact with DNA around Six1, both human SIX1 and SIX2 bind homologous SIX2 enhancers and putative enhancers positioned around SIX1. Transgenic analysis of a putative human SIX1 enhancer in the mouse revealed a transient, mouse-like, pre-nephrogenic, Six1 regulatory pattern. Together, these data demonstrate a divergence in SIX-factor regulation between mouse and human nephron progenitors. In the human, an auto/cross-regulatory loop drives continued SIX1 and SIX2 expression during active nephrogenesis. By contrast, the mouse establishes only an auto-regulatory Six2 loop. These data suggest differential SIX-factor regulation might have contributed to species differences in nephron progenitor programs such as the duration of nephrogenesis and the final nephron count. PMID:26884396

  18. Improved laparoscopic nephron-sparing surgery for renal cell carcinoma based on the precise anatomy of the nephron

    PubMed Central

    Guo, Gang; Cai, Wei; Zhang, Xu

    2016-01-01

    The aim of the present study was to investigate a method of laparoscopic nephron-sparing surgery (LNSS) for renal cell carcinoma (RCC) based on the precise anatomy of the nephron, and to decrease the incidence of hemorrhage and urinary leakage. Between January 2012 and December 2013, 31 patients who presented to the General Hospital of the People's Liberation Army (Beijing, China) were treated for RCC. The mean tumor size was 3.4±0.7 cm in diameter (range, 1.2–6.0 cm). During surgery, the renal artery was blocked, and subsequently, an incision in the renal capsule and renal cortex was performed, at 3–5 mm from the tumor edge. Subsequent to the incision of the renal parenchyma, scissors with blunt and sharp edge were used to separate the base of the tumor from the normal renal medulla, in the direction of the ray medullary in the renal pyramids. The basal blood vessels were incised following the hemostasis of the region using bipolar coagulation. The minor renal calyces were stripped carefully and the wound was closed with an absorbable sutures. The arterial occlusion time, duration of surgery, intraoperative bleeding volume, post-operative drainage volume, pathological results and complications were recorded. The surgery was successful for all patients. The estimated average intraoperative bleeding volume was 55.7 ml, the average surgical duration was 95.5 min, the average arterial occlusion time was 21.2 min, the average post-operative drainage volume was 92.3 ml and the average post-operative length of hospital stay was 6.1 days. No hemorrhage or urinary leakage was observed in the patients following the surgery. LNSS for RCC based on the precise anatomy of the nephron was concluded to be effective and feasible. The surgery is useful for the complete removal of tumors and guarantees a negative margin, which may also decrease the incidence of hemorrhage and urinary leakage following surgery. PMID:27895733

  19. Lengths of nephron tubule segments and collecting ducts in the CD-1 mouse kidney: an ontogeny study.

    PubMed

    Walton, Sarah L; Moritz, Karen M; Bertram, John F; Singh, Reetu R

    2016-11-01

    The kidney continues to mature postnatally, with significant elongation of nephron tubules and collecting ducts to maintain fluid/electrolyte homeostasis. The aim of this project was to develop methodology to estimate lengths of specific segments of nephron tubules and collecting ducts in the CD-1 mouse kidney using a combination of immunohistochemistry and design-based stereology (vertical uniform random sections with cycloid arc test system). Lengths of tubules were determined at postnatal day 21 (P21) and 2 and 12 mo of age and also in mice fed a high-salt diet throughout adulthood. Immunohistochemistry was performed to identify individual tubule segments [aquaporin-1, proximal tubules (PT) and thin descending limbs of Henle (TDLH); uromodulin, distal tubules (DT); aquaporin-2, collecting ducts (CD)]. All tubular segments increased significantly in length between P21 and 2 mo of age (PT, 602% increase; DT, 200% increase; TDLH, 35% increase; CD, 53% increase). However, between 2 and 12 mo, a significant increase in length was only observed for PT (76% increase in length). At 12 mo of age, kidneys of mice on a high-salt diet demonstrated a 27% greater length of the TDLH, but no significant change in length was detected for PT, DT, and CD compared with the normal-salt group. Our study demonstrates an efficient method of estimating lengths of specific segments of the renal tubular system. This technique can be applied to examine structure of the renal tubules in combination with the number of glomeruli in the kidney in models of altered renal phenotype.

  20. Analysis of Nephron Composition and Function in the Adult Zebrafish Kidney

    PubMed Central

    McCampbell, Kristen K.; Springer, Kristin N.; Wingert, Rebecca A.

    2014-01-01

    The zebrafish model has emerged as a relevant system to study kidney development, regeneration and disease. Both the embryonic and adult zebrafish kidneys are composed of functional units known as nephrons, which are highly conserved with other vertebrates, including mammals. Research in zebrafish has recently demonstrated that two distinctive phenomena transpire after adult nephrons incur damage: first, there is robust regeneration within existing nephrons that replaces the destroyed tubule epithelial cells; second, entirely new nephrons are produced from renal progenitors in a process known as neonephrogenesis. In contrast, humans and other mammals seem to have only a limited ability for nephron epithelial regeneration. To date, the mechanisms responsible for these kidney regeneration phenomena remain poorly understood. Since adult zebrafish kidneys undergo both nephron epithelial regeneration and neonephrogenesis, they provide an outstanding experimental paradigm to study these events. Further, there is a wide range of genetic and pharmacological tools available in the zebrafish model that can be used to delineate the cellular and molecular mechanisms that regulate renal regeneration. One essential aspect of such research is the evaluation of nephron structure and function. This protocol describes a set of labeling techniques that can be used to gauge renal composition and test nephron functionality in the adult zebrafish kidney. Thus, these methods are widely applicable to the future phenotypic characterization of adult zebrafish kidney injury paradigms, which include but are not limited to, nephrotoxicant exposure regimes or genetic methods of targeted cell death such as the nitroreductase mediated cell ablation technique. Further, these methods could be used to study genetic perturbations in adult kidney formation and could also be applied to assess renal status during chronic disease modeling. PMID:25145398

  1. Direct Isolation and Characterization of Human Nephron Progenitors.

    PubMed

    Da Sacco, Stefano; Thornton, Matthew E; Petrosyan, Astgik; Lavarreda-Pearce, Maria; Sedrakyan, Sargis; Grubbs, Brendan H; De Filippo, Roger E; Perin, Laura

    2016-09-09

    : Mature nephrons originate from a small population of uninduced nephrogenic progenitor cells (NPs) within the cap mesenchyme. These cells are characterized by the coexpression of SIX2 and CITED1. Many studies on mouse models as well as on human pluripotent stem cells have advanced our knowledge of NPs, but very little is known about this population in humans, since it is exhausted before birth and strategies for its direct isolation are still limited. Here we report an efficient protocol for direct isolation of human NPs without genetic manipulation or stepwise induction procedures. With the use of RNA-labeling probes, we isolated SIX2(+)CITED1(+) cells from human fetal kidney for the first time. We confirmed their nephrogenic state by gene profiling and evaluated their nephrogenic capabilities in giving rise to mature renal cells. We also evaluated the ability to culture these cells without complete loss of SIX2 and CITED1 expression over time. In addition to defining the gene profile of human NPs, this in vitro system facilitates studies of human renal development and provides a novel tool for renal regeneration and bioengineering purposes.

  2. Fibroblast growth factor receptor-Frs2α signaling is critical for nephron progenitors.

    PubMed

    Di Giovanni, Valeria; Walker, Kenneth A; Bushnell, Daniel; Schaefer, Caitlin; Sims-Lucas, Sunder; Puri, Pawan; Bates, Carlton M

    2015-04-01

    Previous studies using transgenic Pax3cre mice have revealed roles for fibroblast growth factor receptors (Fgfrs) and Fgfr substrate 2α (Frs2α) signaling in early metanephric mesenchyme patterning and in ureteric morphogenesis. The role of Fgfr/Frs2α signaling in nephron progenitors is unknown. Thus, we generated mouse models using BAC transgenic Six2EGFPcre (Six2cre) mediated deletion of Fgfrs and/or Frs2α in nephron progenitors. Six2cre mediated deletion of Fgfr1 or Fgfr2 alone led to no obvious kidney defects. Six2creFgfr1(flox/flox)Fgfr2(flox/flox) (Fgfr1/2(NP-/-)) mice generate a discernable kidney; however, they develop nephron progenitor depletion starting at embryonic day 12.5 (E12.5) and later demonstrate severe cystic dysplasia. To determine the role of Frs2α signaling downstream of Fgfr2 in Fgfr1/2(NP-/-) mice, we generated Six2cre(,)Fgfr1(flox/flox)Fgfr2(LR/LR) (Fgfr1(NP-/-)Fgfr2(LR/LR)) mice that have point mutations in the Frs2α binding site of Fgfr2. Like Fgfr1/2(NP-/-) mice, Fgfr1(NP-/-)Fgfr2(LR/LR) develop nephron progenitor depletion, but it does not start until E14.5 and older mice have less severe cystic dysplasia than Fgfr1/2(NP-/-) To determine the role of Frs2α alone in nephron progenitors, we generated Six2creFrs2'A(flox/flox) (Frs2a(NP-/-)) mice. Frs2a(NP-/-)mice also develop nephron progenitor depletion and renal cysts, although these occurred later and were less severe than in the other Six2cre mutant mice. The nephron progenitor loss in all Six2cre mutant lines was associated with decreased Cited1 expression and increased apoptosis versus controls. FAC-sorted nephron progenitors in Six2cre Frs2'A(flox/flox) mice demonstrated evidence of increased Notch activity versus controls, which likely drives the progenitor defects. Thus, Fgfr1 and Fgfr2 have synergistic roles in maintaining nephron progenitors; furthermore, Fgfr signaling in nephron progenitors appears to be mediated predominantly by Frs2α.

  3. Nephron-specific deletion of the prorenin receptor causes a urine concentration defect.

    PubMed

    Ramkumar, Nirupama; Stuart, Deborah; Calquin, Matias; Quadri, Syed; Wang, Shuping; Van Hoek, Alfred N; Siragy, Helmy M; Ichihara, Atsuhiro; Kohan, Donald E

    2015-07-01

    The prorenin receptor (PRR), a recently discovered component of the renin-angiotensin system, is expressed in the nephron in general and the collecting duct in particular. However, the physiological significance of nephron PRR remains unclear, partly due to developmental abnormalities associated with global or renal-specific PRR gene knockout (KO). Therefore, we developed mice with inducible nephron-wide PRR deletion using Pax8-reverse tetracycline transactivator and LC-1 transgenes and loxP flanked PRR alleles such that ablation of PRR occurs in adulthood, after induction with doxycycline. Nephron-specific PRR KO mice have normal survival to ∼1 yr of age and no renal histological defects. Compared with control mice, PRR KO mice had 65% lower medullary PRR mRNA and protein levels and markedly diminished renal PRR immunofluorescence. During both normal water intake and mild water restriction, PRR KO mice had significantly lower urine osmolality, higher water intake, and higher urine volume compared with control mice. No differences were seen in urine vasopressin excretion, urine Na(+) and K(+) excretion, plasma Na(+), or plasma osmolality between the two groups. However, PRR KO mice had reduced medullary aquaporin-2 levels and arginine vasopressin-stimulated cAMP accumulation in the isolated renal medulla compared with control mice. Taken together, these results suggest nephron PRR can potentially modulate renal water excretion.

  4. Distal Biceps Tendon Rupture

    DTIC Science & Technology

    2010-06-01

    distal tendon. Although these findings overlap with those seen in tendinopathy , the presence of bone marrow edema at the radial tuberosity and fluid in...the bicipitoradial bursa suggests a partial tear rather than tendinopathy .3 When the distal biceps tendon tear is complete, MR imaging shows

  5. A New Look at Electrolyte Transport in the Distal Tubule

    PubMed Central

    Eladari, Dominique; Chambrey, Régine; Peti-Peterdi, Janos

    2015-01-01

    The distal nephron plays a critical role in the renal control of homeostasis. Until very recently most studies focused on the control of Na+, K+, and water balance by principal cells of the collecting duct and the regulation of solute and water by hormones from the renin-angiotensin-aldosterone system and by antidiuretic hormone. However, recent studies have revealed the unexpected importance of renal intercalated cells, a subtype of cells present in the connecting tubule and collecting ducts. Such cells were thought initially to be involved exclusively in acid-base regulation. However, it is clear now that intercalated cells absorb NaCl and K+ and hence may participate in the regulation of blood pressure and potassium balance. The second paradigm-challenging concept we highlight is the emerging importance of local paracrine factors that play a critical role in the renal control of water and electrolyte balance. PMID:21888509

  6. A new look at electrolyte transport in the distal tubule.

    PubMed

    Eladari, Dominique; Chambrey, Régine; Peti-Peterdi, Janos

    2012-01-01

    The distal nephron plays a critical role in the renal control of homeostasis. Until very recently most studies focused on the control of Na(+), K(+), and water balance by principal cells of the collecting duct and the regulation of solute and water by hormones from the renin-angiotensin-aldosterone system and by antidiuretic hormone. However, recent studies have revealed the unexpected importance of renal intercalated cells, a subtype of cells present in the connecting tubule and collecting ducts. Such cells were thought initially to be involved exclusively in acid-base regulation. However, it is clear now that intercalated cells absorb NaCl and K(+) and hence may participate in the regulation of blood pressure and potassium balance. The second paradigm-challenging concept we highlight is the emerging importance of local paracrine factors that play a critical role in the renal control of water and electrolyte balance.

  7. Nephron-sparing surgery in renal cell carcinoma: current perspectives on technical issues.

    PubMed

    González, Javier; Cózar, José Manuel; Gómez, Antonio; Fernández-Pérez, Cristina; Esteban, Manuel

    2015-02-01

    Surgical resection remains the standard treatment for renal cell carcinoma. Although historically the concept of wide excision of the affected kidney dictated surgical thinking for more than half a century, a better understanding of the biology of this tumor, standardized staging, and changing patterns of presentation permit today a refined management approach with nephron-sparing surgery, thus limiting potential long-term morbidity by maximizing the preservation of functional renal parenchyma. This paper aims to review the current status of nephron-sparing surgery for solid renal masses with an emphasis on indications, preoperative assessment, and operative technical issues, summarizing the most recent existing data on the subject.

  8. Distal ulnar growth arrest.

    PubMed

    Nelson, O A; Buchanan, J R; Harrison, C S

    1984-03-01

    Four cases of arrest of distal ulnar physeal growth occurring in children ages 7 to 13 years had follow-up for 2 to 10 years. Each patient developed bowing of the radial diaphysis, ulnar translation of the distal radial epiphysis, and increased ulnar angulation of the distal radiocarpal joint surface. Growth discrepancies were documented in both the ulna (range 2.2 to 3.9 cm) and to a lesser extent the radius (range 0.2 to 1.6 cm) when compared to the opposite forearm in each patient. The progression of deformity appeared to be greatest during adolescence. Radial deviation and pronation were limited to varying degrees in each case. No patient had significant pain or functional impairment, but the cosmetic appearance was always displeasing. Indications for surgical treatment include increasing ulnar angulation of the distal radial articular surface, progressive loss of motion, and displeasing cosmetic appearance.

  9. Transphyseal Distal Humerus Fracture.

    PubMed

    Abzug, Joshua; Ho, Christine Ann; Ritzman, Todd F; Brighton, Brian

    2016-01-01

    Transphyseal distal humerus fractures typically occur in children younger than 3 years secondary to birth trauma, nonaccidental trauma, or a fall from a small height. Prompt and accurate diagnosis of a transphyseal distal humerus fracture is crucial for a successful outcome. Recognizing that the forearm is not aligned with the humerus on plain radiographs may aid in the diagnosis of a transphyseal distal humerus fracture. Surgical management is most commonly performed with the aid of an arthrogram. Closed reduction and percutaneous pinning techniques similar to those used for supracondylar humerus fractures are employed. Cubitus varus caused by a malunion, osteonecrosis of the medial condyle, or growth arrest is the most common complication encountered in the treatment of transphyseal distal humerus fractures. A corrective lateral closing wedge osteotomy can be performed to restore a nearly normal carrying angle.

  10. Distal renal tubular acidosis

    MedlinePlus

    ... get better with treatment. When to Contact a Medical Professional Call your health care provider if you have symptoms of distal renal tubular acidosis. Get medical help right away if you develop emergency symptoms ...

  11. Postembryonic Nephrogenesis and Persistence of Six2-Expressing Nephron Progenitor Cells in the Reptilian Kidney

    PubMed Central

    Camarata, Troy; Howard, Alexis; Elsey, Ruth M.; Raza, Sarah; O’Connor, Alice; Beatty, Brian; Conrad, Jack; Solounias, Nikos; Chow, Priscilla; Mukta, Saima; Vasilyev, Aleksandr

    2016-01-01

    New nephron formation (nephrogenesis) ceases in mammals around birth and is completely absent in adults. In contrast, postembryonic nephrogenesis is well documented in the mesonephric kidneys of fishes and amphibians. The transient mesonephros in reptiles (including birds) and mammals is replaced by the metanephros during embryogenesis. Thus, one may speculate that postembryonic nephrogenesis is restricted to the mesonephric kidney. Previous reports have suggested the metanephros of non-avian reptiles (hereafter reptiles) may continually form nephrons throughout life. We investigated the presence of adult nephrogenesis in reptiles by examining adult kidneys from several species including Trachemys scripta, Chrysemys picta, Boa constrictor, Tupinambis tegu, Anolis carolinensis, and Alligator mississipiensis among others. We found that all major reptilian groups (Testudines, Crocodylia, and Squamates) showed the presence of adult nephrogenesis. The total amount of nephrogenesis varied greatly between species with turtles displaying the highest density of nephrogenesis. In contrast, we were unable to detect adult nephrogenesis in monotremes, and in the iguanid A. carolinensis. Nephron progenitor cells express the transcription factor Six2, which in mammals, becomes downregulated as the progenitor cell population is exhausted and nephrogenesis ends. Using the alligator as a model, we were able to detect Six2-positive cap mesenchyme cells in the adult kidney, which spatially correlated with areas of nephrogenesis. These results suggest that the metanephric kidney of reptiles has maintained the ability to continually grow new nephrons during postembryonic life, a process lost early in mammalian evolution, likely due to the persistence of a Six2-expressing progenitor cell population. PMID:27144443

  12. An Active Learning Exercise to Facilitate Understanding of Nephron Function: Anatomy and Physiology of Renal Transporters

    ERIC Educational Resources Information Center

    Dirks-Naylor, Amie J.

    2016-01-01

    Renal transport is a central mechanism underlying electrolyte homeostasis, acid base balance and other essential functions of the kidneys in human physiology. Thus, knowledge of the anatomy and physiology of the nephron is essential for the understanding of kidney function in health and disease. However, students find this content difficult to…

  13. Postembryonic Nephrogenesis and Persistence of Six2-Expressing Nephron Progenitor Cells in the Reptilian Kidney.

    PubMed

    Camarata, Troy; Howard, Alexis; Elsey, Ruth M; Raza, Sarah; O'Connor, Alice; Beatty, Brian; Conrad, Jack; Solounias, Nikos; Chow, Priscilla; Mukta, Saima; Vasilyev, Aleksandr

    2016-01-01

    New nephron formation (nephrogenesis) ceases in mammals around birth and is completely absent in adults. In contrast, postembryonic nephrogenesis is well documented in the mesonephric kidneys of fishes and amphibians. The transient mesonephros in reptiles (including birds) and mammals is replaced by the metanephros during embryogenesis. Thus, one may speculate that postembryonic nephrogenesis is restricted to the mesonephric kidney. Previous reports have suggested the metanephros of non-avian reptiles (hereafter reptiles) may continually form nephrons throughout life. We investigated the presence of adult nephrogenesis in reptiles by examining adult kidneys from several species including Trachemys scripta, Chrysemys picta, Boa constrictor, Tupinambis tegu, Anolis carolinensis, and Alligator mississipiensis among others. We found that all major reptilian groups (Testudines, Crocodylia, and Squamates) showed the presence of adult nephrogenesis. The total amount of nephrogenesis varied greatly between species with turtles displaying the highest density of nephrogenesis. In contrast, we were unable to detect adult nephrogenesis in monotremes, and in the iguanid A. carolinensis. Nephron progenitor cells express the transcription factor Six2, which in mammals, becomes downregulated as the progenitor cell population is exhausted and nephrogenesis ends. Using the alligator as a model, we were able to detect Six2-positive cap mesenchyme cells in the adult kidney, which spatially correlated with areas of nephrogenesis. These results suggest that the metanephric kidney of reptiles has maintained the ability to continually grow new nephrons during postembryonic life, a process lost early in mammalian evolution, likely due to the persistence of a Six2-expressing progenitor cell population.

  14. FGF/EGF signaling regulates the renewal of early nephron progenitors during embryonic development.

    PubMed

    Brown, Aaron C; Adams, Derek; de Caestecker, Mark; Yang, Xuehui; Friesel, Robert; Oxburgh, Leif

    2011-12-01

    Recent studies indicate that nephron progenitor cells of the embryonic kidney are arranged in a series of compartments of an increasing state of differentiation. The earliest progenitor compartment, distinguished by expression of CITED1, possesses greater capacity for renewal and differentiation than later compartments. Signaling events governing progression of nephron progenitor cells through stages of increasing differentiation are poorly understood, and their elucidation will provide key insights into normal and dysregulated nephrogenesis, as well as into regenerative processes that follow kidney injury. In this study, we found that the mouse CITED1(+) progenitor compartment is maintained in response to receptor tyrosine kinase (RTK) ligands that activate both FGF and EGF receptors. This RTK signaling function is dependent on RAS and PI3K signaling but not ERK. In vivo, RAS inactivation by expression of sprouty 1 (Spry1) in CITED1(+) nephron progenitors results in loss of characteristic molecular marker expression and in increased death of progenitor cells. Lineage tracing shows that surviving Spry1-expressing progenitor cells are impaired in their subsequent epithelial differentiation, infrequently contributing to epithelial structures. These findings demonstrate that the survival and developmental potential of cells in the earliest embryonic nephron progenitor cell compartment are dependent on FGF/EGF signaling through RAS.

  15. Reduced nephron endowment due to fetal uninephrectomy impairs renal sodium handling in male sheep.

    PubMed

    Singh, Reetu R; Denton, Kate M; Bertram, John F; Jefferies, Andrew J; Moritz, Karen M

    2010-03-09

    Reduced nephron endowment is associated with development of renal and cardiovascular disease. We hypothesized this may be attributable to impaired sodium homoeostasis by the remaining nephrons. The present study investigated whether a nephron deficit, induced by fetal uninephrectomy at 100 days gestation (term=150 days), resulted in (i) altered renal sodium handling both under basal conditions and in response to an acute 0.9% saline load (50 ml.kg-1 of body weight.30 min-1); (ii) hypertension and (iii) altered expression of renal channels/transporters in male sheep at 6 months of age. Uninephrectomized animals had significantly elevated arterial pressure (90.1+/-1.6 compared with 77.8+/-2.9 mmHg; P<0.001), while glomerular filtration rate and renal blood flow (per g of kidney weight) were 30% lower than that of the sham animals. Total kidney weight was similar between the groups. Renal gene expression of apical NHE3 (type 3 Na+/H+ exchanger), ENaC (epithelium Na+ channel) beta and gamma subunits and basolateral Na+/K+ ATPase beta and gamma subunits were significantly elevated in uninephrectomized animals, while ENaC alpha subunit expression was reduced. Urine flow rate and sodium excretion increased in both groups in response to salt loading, but this increase in sodium excretion was delayed by approximately 90 min in the uninephrectomized animals, while total sodium output was 12% in excess of the infused load (P<0.05). In conclusion, the present study shows that animals with a congenital nephron deficit have alterations in tubular sodium channels/transporters and cannot rapidly correct for variations in sodium intake probably contributing to the development of hypertension. This suggests that people born with a nephron deficit should be monitored for early signs of renal and cardiovascular disease.

  16. Lats1/2 Regulate Yap/Taz to Control Nephron Progenitor Epithelialization and Inhibit Myofibroblast Formation.

    PubMed

    McNeill, Helen; Reginensi, Antoine

    2017-03-01

    In the kidney, formation of the functional filtration units, the nephrons, is essential for postnatal life. During development, mesenchymal progenitors tightly regulate the balance between self-renewal and differentiation to give rise to all nephron epithelia. Here, we investigated the functions of the Hippo pathway serine/threonine-protein kinases Lats1 and Lats2, which phosphorylate and inhibit the transcriptional coactivators Yap and Taz, in nephron progenitor cells. Genetic deletion of Lats1 and Lats2 in nephron progenitors of mice led to disruption of nephrogenesis, with an accumulation of spindle-shaped cells in both cortical and medullary regions of the kidney. Lineage-tracing experiments revealed that the cells that accumulated in the interstitium derived from nephron progenitor cells and expressed E-cadherin as well as vimentin, a myofibroblastic marker not usually detected after mesenchymal-to-epithelial transition. The accumulation of these interstitial cells associated with collagen deposition and ectopic expression of the myofibroblastic markers vimentin and α-smooth-muscle actin in developing kidneys. Although these myofibroblastic cells had high Yap and Taz accumulation in the nucleus concomitant with a loss of phosphorylated Yap, reduction of Yap and/or Taz expression levels completely rescued the Lats1/2 phenotype. Taken together, our results demonstrate that Lats1/2 kinases restrict Yap/Taz activities to promote nephron progenitor cell differentiation in the mammalian kidney. Notably, our data also show that myofibroblastic cells can differentiate from nephron progenitors.

  17. Laparoscopic Distal Pancreatectomy

    PubMed Central

    Melotti, Gianluigi; Butturini, Giovanni; Piccoli, Micaela; Casetti, Luca; Bassi, Claudio; Mullineris, Barbara; Lazzaretti, Maria Grazia; Pederzoli, Paolo

    2007-01-01

    Objective: To describe the clinical characteristics, indications, technical procedures, and outcome of a consecutive series of laparoscopic distal pancreatic resections performed by the same surgical team. Summary Background Data: Laparoscopic distal pancreatic resection has increasingly been described as a feasible and safe procedure, although accompanied by a high rate of conversion and morbidity. Methods: A consecutive series of patients affected by solid and cystic tumors were selected prospectively to undergo laparoscopic distal pancreatectomy performed by the same surgical team. Clinical characteristics as well as diagnostic preoperative assessment and intra- and postoperative data were prospectively recorded. A follow-up of at least 3 months was available for all patients. Results: Fifty-eight patients underwent laparoscopic resection between May 1999 and November 2005. All procedures were successfully performed laparoscopically, and no patient required intraoperative blood transfusion. Splenic vessel preservation was possible in 84.4% of spleen-preserving procedures. There were no mortalities. The overall median hospital stay was 9 days, while it was 10.5 days for patients with postoperative pancreatic fistulae (27.5% of all cases). Follow-up was available for all patients. Conclusions: Our experience in 58 consecutive patients was characterized by the lack of conversions and by acceptable rates of postoperative pancreatic fistulae and morbidity. Laparoscopy proved especially beneficial in patients with postoperative complications as they had a relatively short hospital stay. Solid and cystic tumors of the distal pancreas represent a good indication for laparoscopic resection whenever possible. PMID:17592294

  18. Standardized reporting of resection technique during nephron-sparing surgery: the surface-intermediate-base margin score.

    PubMed

    Minervini, Andrea; Carini, Marco; Uzzo, Robert G; Campi, Riccardo; Smaldone, Marc C; Kutikov, Alexander

    2014-11-01

    A standardized reporting system of nephron-sparing surgery resection techniques is lacking. The surface-intermediate-base scoring system represents a formal reporting instrument to assist in interpretation of reported data and to facilitate comparisons in the urologic literature.

  19. Concept and computational design for a bioartificial nephron-on-a-chip.

    PubMed

    Weinberg, E; Kaazempur-Mofrad, M; Borenstein, J

    2008-06-01

    A MEMS-based, (Micro Electro Mechanical System) bioartificial device is proposed for replicating the function of a single nephron. Consistent with the anatomy and physiology of humans, our device has 3 distinct sections, replicating the function of the glomerulus, the proximal tubule, and the loop of Henle. Construction of a bioartificial loop of Henle in particular requires control of diffusion-scale features. The proposed device can be built using existing microfabrication technologies and populated with various renal cell types. A computational model is also developed to analyze the coupled, multiphase mass transport in this system. Using the model, a design is generated with flow and solute transport properties matching those of the human nephron.

  20. High glucose promotes nascent nephron apoptosis via NF-kappaB and p53 pathways.

    PubMed

    Chen, Yun-Wen; Chenier, Isabelle; Chang, Shiao-Ying; Tran, Stella; Ingelfinger, Julie R; Zhang, Shao-Ling

    2011-01-01

    A hyperglycemic environment in utero reduces kidney size and nephron number due to nascent nephron apoptosis. However, the underlying mechanisms are incompletely understood. The present study investigated whether the nascent nephron apoptosis promoted by high glucose is mediated via the transcription factor NF-κB and p53 signaling pathways. Neonatal mouse kidneys from the offspring of nondiabetic, diabetic, and insulin-treated diabetic dams were used for in vivo studies, and MK4 cells, an embryonic metanephric mesenchymal (MM) cell line, were used for in vitro studies. Neonatal kidneys of the offspring of diabetic mothers exhibited an increased number of apoptotic cells and reactive oxygen species (ROS) generation, enhanced NF-κB activation, and nuclear translocation of its subunits (p50 and p65 subunits) as well as phosphorylation (Ser 15) of p53 compared with kidneys of offspring of nondiabetic mothers. Insulin treatment of diabetic dams normalized these parameters in the offspring. In vitro, high-glucose (25 mM) induced ROS generation and significantly increased MK4 cell apoptosis and caspase-3 activity via activation of NF-κB pathway, with p53 phosphorylation and nuclear translocation compared with normal glucose (5 mM). These changes in a high-glucose milieu were prevented by transient transfection of small interfering RNAs for dominant negative IκBα or IKK or p53. Our data demonstrate that high glucose-induced nascent nephron apoptosis is mediated, at least in part, via ROS generation and the activation of NF-κB and p53 pathways.

  1. Coupled CFD-PBE Predictions of Renal Stone Size Distributions in the Nephron in Microgravity

    NASA Technical Reports Server (NTRS)

    Kassemi, Mohammad; Griffin, Elise; Thompson, David

    2017-01-01

    In this paper, a deterministic model is developed to assess the risk of critical renal stone formation for astronauts during space travel. A Population Balance Equation (PBE) model is used to compute the size distribution of a population of nucleating, growing and agglomerating renal calculi as they are transported through different sections of the nephron. The PBE model is coupled to a Computational Fluid Dynamics (CFD) model that solves for steady state flow of urine and transport of renal calculi along with the concentrations of ionic species, calcium and oxalate, in the nephron using an Eulerian two-phase mathematical framework. Parametric simulation are performed to study stone size enhancement and steady state volume fraction distributions in the four main sections of the nephron under weightlessness conditions. Contribution of agglomeration to the stone size distribution and effect of wall friction on the stone volume fraction distributions are carefully examined. Case studies using measured astronaut urinary calcium and oxalate concentrations in microgravity as input indicate that under nominal conditions the largest stone sizes developed in Space will be still considerably below the critical range for problematic stone development. However, results also indicate that the highest stone volume fraction occurs next to the tubule and duct walls. This suggests that there is an increased potential for wall adhesion with the possibility of evolution towards critical stone sizes.

  2. Progression of renal fibrosis in congenital CKD model rats with reduced number of nephrons.

    PubMed

    Yasuda, Hidenori; Tochigi, Yuki; Katayama, Kentaro; Suzuki, Hiroetsu

    2017-02-06

    A congenital reduction in the number of nephrons is a critical risk factor for both onset of chronic kidney disease (CKD) and its progression to end-stage kidney disease (ESKD). Hypoplastic kidney (HPK) rats have only about 20% of the normal number of nephrons and show progressive CKD. This study used an immunohistological method to assess glomerular and interstitial pathogenesis in male HPK rats aged 35-210days. CD68 positive-macrophages were found to infiltrate into glomeruli in HPK rats aged 35 and 70days and to infiltrate into interstitial tissue in rats aged 140 and 210days. HPK rats aged 35 and 70days showed glomerular hypertrophy, loss of normal linear immunostaining of podocine, and increased expression of PDGFr-β, TGF-β, collagens, and fibronectin, with all of these alterations gradually deteriorating with age. α-SMA-positive myofibroblasts were rarely detected in glomerular tufts, whereas α-SMA-positive glomerular parietal epithelium (GPE) cells were frequently observed along Bowman's capsular walls. The numbers of PDGFr-β-positive fibroblasts in interstitial tissue were increased in rats aged 35days and older, whereas interstitial fibrosis, characterized by the increased expression of tubular PDGF-BB, the appearance of myofibroblasts doubly positive for PDGFr-β and α-SMA, and increased expression of collagens and fibronectin, were observed in rats aged 70 and older. These results clearly indicate that congenital CKD with only 20% of nephrons cause renal fibrosis in rats.

  3. Distal Radioulnar Joint Instability

    PubMed Central

    Mirghasemi, Ali R.; Lee, Daniel J.; Rahimi, Narges; Rashidinia, Shervin

    2015-01-01

    Distal radioulnar joint (DRUJ) instability is a common clinical condition but a frequently missed diagnosis. Both surgical and nonsurgical treatments are possible for chronic cases of DRUJ instability. Nonsurgical treatment can be considered as the primary therapy in less active patients, while surgery should be considered to recover bone and ligament injuries if nonsurgical treatment fails to restore forearm stability and function. The appropriate choice of treatment depends on the individual patient and specific derangement of the DRUJ PMID:26328241

  4. Distal radioulnar joint injuries

    PubMed Central

    Thomas, Binu P; Sreekanth, Raveendran

    2012-01-01

    Distal radioulnar joint is a trochoid joint relatively new in evolution. Along with proximal radioulnar joint, forearm bones and interosseous membrane, it allows pronosupination and load transmission across the wrist. Injuries around distal radioulnar joint are not uncommon, and are usually associated with distal radius fractures,fractures of the ulnar styloid and with the eponymous Galeazzi or Essex_Lopresti fractures. The injury can be purely involving the soft tissue especially the triangular fibrocartilage or the radioulnar ligaments. The patients usually present with ulnar sided wrist pain, features of instability, or restriction of rotation. Difficulty in carrying loads in the hand is a major constraint for these patients. Thorough clinical examination to localize point of tenderness and appropriate provocative tests help in diagnosis. Radiology and MRI are extremely useful, while arthroscopy is the gold standard for evaluation. The treatment protocols are continuously evolving and range from conservative, arthroscopic to open surgical methods. Isolated dislocation are uncommon. Basal fractures of the ulnar styloid tend to make the joint unstable and may require operative intervention. Chronic instability requires reconstruction of the stabilizing ligaments to avoid onset of arthritis. Prosthetic replacement in arthritis is gaining acceptance in the management of arthritis. PMID:23162140

  5. Distal tibiofibular radiological overlap

    PubMed Central

    Sowman, B.; Radic, R.; Kuster, M.; Yates, P.; Breidiel, B.; Karamfilef, S.

    2012-01-01

    Objectives Overlap between the distal tibia and fibula has always been quoted to be positive. If the value is not positive then an injury to the syndesmosis is thought to exist. Our null hypothesis is that it is a normal variant in the adult population. Methods We looked at axial CT scans of the ankle in 325 patients for the presence of overlap between the distal tibia and fibula. Where we thought this was possible we reconstructed the images to represent a plain film radiograph which we were able to rotate and view in multiple planes to confirm the assessment. Results The scans were taken for reasons other than pathology of the ankle. We found there was no overlap in four patients. These patients were then questioned about previous injury, trauma, surgery or pain, in order to exclude underlying pathology. Conclusion We concluded that no overlap between the tibia and fibula may exist in the population, albeit in a very small proportion. PMID:23610666

  6. Identification of human nephron progenitors capable of generation of kidney structures and functional repair of chronic renal disease

    PubMed Central

    Harari-Steinberg, Orit; Metsuyanim, Sally; Omer, Dorit; Gnatek, Yehudit; Gershon, Rotem; Pri-Chen, Sara; Ozdemir, Derya D; Lerenthal, Yaniv; Noiman, Tzahi; Ben-Hur, Herzel; Vaknin, Zvi; Schneider, David F; Aronow, Bruce J; Goldstein, Ronald S; Hohenstein, Peter; Dekel, Benjamin

    2013-01-01

    Identification of tissue-specific renal stem/progenitor cells with nephrogenic potential is a critical step in developing cell-based therapies for renal disease. In the human kidney, stem/progenitor cells are induced into the nephrogenic pathway to form nephrons until the 34 week of gestation, and no equivalent cell types can be traced in the adult kidney. Human nephron progenitor cells (hNPCs) have yet to be isolated. Here we show that growth of human foetal kidneys in serum-free defined conditions and prospective isolation of NCAM1+ cells selects for nephron lineage that includes the SIX2-positive cap mesenchyme cells identifying a mitotically active population with in vitro clonogenic and stem/progenitor properties. After transplantation in the chick embryo, these cells—but not differentiated counterparts—efficiently formed various nephron tubule types. hNPCs engrafted and integrated in diseased murine kidneys and treatment of renal failure in the 5/6 nephrectomy kidney injury model had beneficial effects on renal function halting disease progression. These findings constitute the first definition of an intrinsic nephron precursor population, with major potential for cell-based therapeutic strategies and modelling of kidney disease. PMID:23996934

  7. Role of intra-operative contrast-enhanced ultrasound (CEUS) in robotic-assisted nephron-sparing surgery.

    PubMed

    Alenezi, Ahmad N; Karim, Omer

    2015-03-01

    This review examines studies of intra-operative contrast-enhanced ultrasound (CEUS) and its emerging role and advantages in robotic-assisted nephron-sparing surgery. Contrast-enhanced ultrasound is a technology that combines the use of second-generation contrast agents consisting of microbubbles with existent ultrasound techniques. Until now, this novel technology has aided surgeons with procedures involving the liver. However, with recent advances in the CEUS technique and the introduction of robotics in nephron-sparing surgery, CEUS has proven to be efficacious in answering several clinical questions with respect to the kidneys. In addition, the introduction of the microbubble-based contrast agents has increased the image quality and signal uptake by the ultrasound probe. This has led to better, enhanced scanning of the macro and microvasculature of the kidneys, making CEUS a powerful diagnostic modality. This imaging method is capable of further lowering the learning curve and warm ischemia time (WIT) during robotic-assisted nephron-sparing surgery, with its increased level of capillary perfusion and imaging. CEUS has the potential to increase the sensitivity and specificity of intra-operative images, and can significantly improve the outcome of robotic-assisted nephron-sparing surgery by increasing the precision and diagnostic insight of the surgeon. The purpose of this article is to review the practical and potential uses of CEUS as an intra-operative imaging technique during robotic-assisted nephron-sparing surgery.

  8. Stromal Fat4 acts non-autonomously with Dchs1/2 to restrict the nephron progenitor pool.

    PubMed

    Bagherie-Lachidan, Mazdak; Reginensi, Antoine; Pan, Qun; Zaveri, Hitisha P; Scott, Daryl A; Blencowe, Benjamin J; Helmbacher, Françoise; McNeill, Helen

    2015-08-01

    Regulation of the balance between progenitor self-renewal and differentiation is crucial to development. In the mammalian kidney, reciprocal signalling between three lineages (stromal, mesenchymal and ureteric) ensures correct nephron progenitor self-renewal and differentiation. Loss of either the atypical cadherin FAT4 or its ligand Dachsous 1 (DCHS1) results in expansion of the mesenchymal nephron progenitor pool, called the condensing mesenchyme (CM). This has been proposed to be due to misregulation of the Hippo kinase pathway transcriptional co-activator YAP. Here, we use tissue-specific deletions to prove that FAT4 acts non-autonomously in the renal stroma to control nephron progenitors. We show that loss of Yap from the CM in Fat4-null mice does not reduce the expanded CM, indicating that FAT4 regulates the CM independently of YAP. Analysis of Six2(-/-);Fat4(-/-) double mutants demonstrates that excess progenitors in Fat4 mutants are dependent on Six2, a crucial regulator of nephron progenitor self-renewal. Electron microscopy reveals that cell organisation is disrupted in Fat4 mutants. Gene expression analysis demonstrates that the expression of Notch and FGF pathway components are altered in Fat4 mutants. Finally, we show that Dchs1, and its paralogue Dchs2, function in a partially redundant fashion to regulate the number of nephron progenitors. Our data support a model in which FAT4 in the stroma binds to DCHS1/2 in the mouse CM to restrict progenitor self-renewal.

  9. Adaptation of the distal convoluted tubule of the rat. Structural and functional effects of dietary salt intake and chronic diuretic infusion.

    PubMed Central

    Ellison, D H; Velázquez, H; Wright, F S

    1989-01-01

    We studied the effects of dietary NaCl intake on the renal distal tubule by feeding rats high or low NaCl chow or by chronically infusing furosemide. Furosemide-treated animals were offered saline as drinking fluid to replace urinary losses. Effects of naCl intake were evaluated using free-flow micropuncture, in vivo microperfusion, and morphometric techniques. Dietary NaCl restriction did not affect NaCl delivery to the early distal tubule but markedly increased the capacity of the distal convoluted tubule to transport Na and Cl. Chronic furosemide infusion increased NaCl delivery to the early distal tubule and also increased the rates of Na and Cl transport above the rates observed in low NaCl diet rats. When compared with high NaCl intake alone, chronic furosemide infusion with saline ingestion increased the fractional volume of distal convoluted tubule cells by nearly 100%, whereas dietary NaCl restriction had no effect. The results are consistent with the hypotheses that (a) chronic NaCl restriction increases the transport ability of the distal convoluted tubule independent of changes in tubule structure, (b) high rates of ion delivery to the distal nephron cause tubule hypertrophy, and (c) tubule hypertrophy is associated with increases in ion transport capacity. They indicate that the distal tubule adapts functionally and structurally to perturbations in dietary Na and Cl intake. Images PMID:2910903

  10. Measurement of Na-K-ATPase-mediated rubidium influx in single segments of rat nephron

    SciTech Connect

    Cheval, L.; Doucet, A. )

    1990-07-01

    To determine the functioning rate of Na-K-ATPase in the rat nephron, a micromethod was developed to measure the rate of rubidium uptake in single nephron segments microdissected from collagenase-treated kidneys. Because the hydrolytic activity of Na-K-ATPase displayed the same apparent affinity for K and Rb ions, whereas the Vmax elicited by K was higher than that in the presence of Rb, experiments were performed in the presence of cold Rb plus 86Rb. Before the assay, tubules were preincubated for 10 min at 37 degrees C to restore the normal transmembrane cation gradients. 86Rb uptake was measured after washing out extracellular cations by rinsing the tubules in ice-cold choline chloride solution containing Ba2+. Rb uptake increased quasi-linearly as a function of incubation time up to 30 s in the thick ascending limb, 1 min in the proximal convoluted tubule, and 5 min in the collecting tubule, and reached an equilibrium after 5-30 min. The initial rates of Rb uptake increased in a saturable fashion as Rb concentration in the medium rose from 0.25 to 5 mM. In medullary thick ascending limb, the initial rate of Rb uptake was inhibited by greater than 90% by 2.5 mM ouabain and by 10(-5) M of the metabolic inhibitor carbonyl cyanide trifluoromethoxyphenylhydrazone. Correlation of Na-K-ATPase hydrolytic activity at Vmax and initial rates of ouabain-sensitive Rb uptake in the successive segments of nephron indicates that in intact cells the pump works at approximately 20-30% of its Vmax. Increasing intracellular Na concentration by tubule preincubation in a Rb- and K-free medium increased the initial rates of Rb intake up to the Vmax of the hydrolytic activity of the pump.

  11. Repeated ethanol exposure during late gestation decreases nephron endowment in fetal sheep.

    PubMed

    Gray, Stephen P; Kenna, Kelly; Bertram, John F; Hoy, Wendy E; Yan, Edwin B; Bocking, Alan D; Brien, James F; Walker, David W; Harding, Richard; Moritz, Karen M

    2008-08-01

    Maternal alcohol consumption during pregnancy can affect fetal development, but little is known about the effects on the developing kidney. Our objectives were to determine the effects of repeated ethanol exposure during the latter half of gestation on glomerular (nephron) number and expression of key genes involved in renal development or function in the ovine fetal kidney. Pregnant ewes received daily intravenous infusion of ethanol (0.75 g/kg, n=5) or saline (control, n=5) over 1 h from 95 to 133 days of gestational age (DGA; term is approximately 147 DGA). Maternal and fetal arterial blood samples were taken before and after the start of the daily ethanol infusions for determination of blood ethanol concentration (BEC). Necropsy was performed at 134 DGA, and fetal kidneys were collected for determination of total glomerular number using the physical disector/fractionator technique; at this gestational age nephrogenesis is completed in sheep. Maximal maternal and fetal BECs of 0.12+/-0.01 g/dl (mean+/-SE) and 0.11+/-0.01 g/dl, respectively, were reached 1 h after starting maternal ethanol infusions. Ethanol exposure had no effect on fetal body weight, kidney weight, or the gene expression of members of the renin-angiotensin system, insulin-like growth factors, and sodium channels. However, fetal glomerular number was lower after ethanol exposure (377,585+/-8,325) than in controls (423,177+/-17,178, P<0.001). The data demonstrate that our regimen of fetal ethanol exposure during the latter half of gestation results in an 11% reduction in nephron endowment without affecting the overall growth of the kidney or fetus or the expression of key genes involved in renal development or function. A reduced nephron endowment of this magnitude could have important implications for the cardiovascular health of offspring during postnatal life.

  12. Nephron Deficiency and Predisposition to Renal Injury in a Novel One-Kidney Genetic Model.

    PubMed

    Wang, Xuexiang; Johnson, Ashley C; Williams, Jan M; White, Tiffani; Chade, Alejandro R; Zhang, Jie; Liu, Ruisheng; Roman, Richard J; Lee, Jonathan W; Kyle, Patrick B; Solberg-Woods, Leah; Garrett, Michael R

    2015-07-01

    Some studies have reported up to 40% of patients born with a single kidney develop hypertension, proteinuria, and in some cases renal failure. The increased susceptibility to renal injury may be due, in part, to reduced nephron numbers. Notably, children who undergo nephrectomy or adults who serve as kidney donors exhibit little difference in renal function compared with persons who have two kidneys. However, the difference in risk between being born with a single kidney versus being born with two kidneys and then undergoing nephrectomy are unclear. Animal models used previously to investigate this question are not ideal because they require invasive methods to model congenital solitary kidney. In this study, we describe a new genetic animal model, the heterogeneous stock-derived model of unilateral renal agenesis (HSRA) rat, which demonstrates 50%-75% spontaneous incidence of a single kidney. The HSRA model is characterized by reduced nephron number (more than would be expected by loss of one kidney), early kidney/glomerular hypertrophy, and progressive renal injury, which culminates in reduced renal function. Long-term studies of temporal relationships among BP, renal hemodynamics, and renal function demonstrate that spontaneous single-kidney HSRA rats are more likely than uninephrectomized normal littermates to exhibit renal impairment because of the combination of reduced nephron numbers and prolonged exposure to renal compensatory mechanisms (i.e., hyperfiltration). Future studies with this novel animal model may provide additional insight into the genetic contributions to kidney development and agenesis and the factors influencing susceptibility to renal injury in individuals with congenital solitary kidney.

  13. [Laparoscopic nephron-sparing surgery for Wilms tumor: description of two cases].

    PubMed

    López, L; Copete, M; Villamizar, P

    2016-01-25

    Surgical resection is the mainstay of treatment for Wilms tumor. The research progress of the large study groups worldwide has reduced mortality. However, searching to minimize morbidity, the minimally invasive approach has been applied in selected patients. This article describes two cases of Wilms tumor managed with laparoscopic nephron sparing surgery. The case 1 with Beckwith-Wiedemann syndrome and bilateral disease, and the case 2 non-syndromic unilateral. The approach was intraperitoneally, without intraoperative complications. The follow-up to 18 months (case 1) and six months (case 2) did not have recurrence or metastatic disease.

  14. Distal arthrogryposis syndrome

    PubMed Central

    Kulkarni, K. P.; Panigrahi, I.; Ray, M.; Marwaha, R. K.

    2008-01-01

    A 5-month-old male infant presented with weak cry, decreased body movements, tightness of whole body since birth, and one episode of generalized seizure on day 4 of life. He was born at term by elective caesarian section performed for breech presentation. The child had failure to thrive, contractures at elbow and knee joints, hypertonia, microcephaly, small mouth, retrognathia, and camptodactyly. There was global developmental delay. Abdominal examination revealed umbilical and bilateral inguinal hernia. Visual evoked response and brainstem evoked response audiometry were abnormal. Nerve conduction velocity was normal. Magnetic resonance imaging of brain revealed paucity of white matter in bilateral cerebral hemispheres with cerebellar and brain stem atrophy. The differential diagnoses considered in the index patient were distal arthrogryposis (DA) syndrome, cerebroculofacioskeletal syndrome, and Pena Shokier syndrome. The index patient most likely represents a variant of DA: Sheldon Hall syndrome. PMID:20300297

  15. Cellular interactions via conditioned media induce in vivo nephron generation from tubular epithelial cells or mesenchymal stem cells

    SciTech Connect

    Machiguchi, Toshihiko Nakamura, Tatsuo

    2013-06-07

    Highlights: •We have attempted in vivo nephron generation using conditioned media. •Vascular and tubular cells do cross-talks on cell proliferation and tubular changes. •Tubular cells suppress these changes in mesenchymal stem cells. •Tubular cells differentiate mesenchymal stem cells into tubular cells. •Nephrons can be created from implanted tubular cells or mesenchymal stem cells. -- Abstract: There are some successful reports of kidney generation by utilizing the natural course of kidney development, namely, the use of an artificially treated metanephros, blastocyst or ureteric bud. Under a novel concept of cellular interactions via conditioned media (CMs), we have attempted in vivo nephron generation from tubular epithelial cells (TECs) or mesenchymal stem cells (MSCs). Here we used 10× CMs of vascular endothelial cells (VECs) and TECs, which is the first to introduce a CM into the field of organ regeneration. We first present stimulative cross-talks induced by these CMs between VECs and TECs on cell proliferation and morphological changes. In MSCs, TEC-CM suppressed these changes, however, induced cytokeratin expression, indicating the differentiation of MSCs into TECs. As a result, glomerular and tubular structures were created following the implantation of TECs or MSCs with both CMs. Our findings suggest that the cellular interactions via CMs might induce in vivo nephron generation from TECs or MSCs. As a promoting factor, CMs could also be applied to the regeneration of other organs and tissues.

  16. Solute transport and oxygen consumption along the nephrons: effects of Na+ transport inhibitors.

    PubMed

    Layton, Anita T; Laghmani, Kamel; Vallon, Volker; Edwards, Aurélie

    2016-12-01

    Sodium and its associated anions are the major determinant of extracellular fluid volume, and the reabsorption of Na(+) by the kidney plays a crucial role in long-term blood pressure control. The goal of this study was to investigate the extent to which inhibitors of transepithelial Na(+) transport (TNa) along the nephron alter urinary solute excretion and TNa efficiency and how those effects may vary along different nephron segments. To accomplish that goal, we used the multinephron model developed in the companion study (28). That model represents detailed transcellular and paracellular transport processes along the nephrons of a rat kidney. We simulated the inhibition of the Na(+)/H(+) exchanger (NHE3), the bumetanide-sensitive Na(+)-K(+)-2Cl(-) transporter (NKCC2), the Na(+)-Cl(-) cotransporter (NCC), and the amiloride-sensitive Na(+) channel (ENaC). Under baseline conditions, NHE3, NKCC2, NCC, and ENaC reabsorb 36, 22, 4, and 7%, respectively, of filtered Na(+) The model predicted that inhibition of NHE3 substantially reduced proximal tubule TNa and oxygen consumption (QO2 ). Whole-kidney TNa efficiency, as reflected by the number of moles of Na(+) reabsorbed per moles of O2 consumed (denoted by the ratio TNa/QO2 ), decreased by ∼20% with 80% inhibition of NHE3. NKCC2 inhibition simulations predicted a substantial reduction in thick ascending limb TNa and QO2 ; however, the effect on whole-kidney TNa/QO2 was minor. Tubular K(+) transport was also substantially impaired, resulting in elevated urinary K(+) excretion. The most notable effect of NCC inhibition was to increase the excretion of Na(+), K(+), and Cl(-); its impact on whole-kidney TNa and its efficiency was minor. Inhibition of ENaC was predicted to have opposite effects on the excretion of Na(+) (increased) and K(+) (decreased) and to have only a minor impact on whole-kidney TNa and TNa/QO2 Overall, model predictions agree well with measured changes in Na(+) and K(+) excretion in response to

  17. Tubuloglomerular and connecting tubuloglomerular feedback during inhibition of various Na transporters in the nephron.

    PubMed

    Wang, Hong; D'Ambrosio, Martin A; Ren, YiLin; Monu, Sumit R; Leung, Pablo; Kutskill, Kristopher; Garvin, Jeffrey L; Janic, Branislava; Peterson, Edward L; Carretero, Oscar A

    2015-05-01

    Afferent (Af-Art) and efferent arterioles resistance regulate glomerular capillary pressure. The nephron regulates Af-Art resistance via: 1) vasoconstrictor tubuloglomerular feedback (TGF), initiated in the macula densa via Na-K-2Cl cotransporters (NKCC2) and 2) vasodilator connecting tubuloglomerular feedback (CTGF), initiated in connecting tubules via epithelial Na channels (ENaC). Furosemide inhibits NKCC2 and TGF. Benzamil inhibits ENaC and CTGF. In vitro, CTGF dilates preconstricted Af-Arts. In vivo, benzamil decreases stop-flow pressure (PSF), suggesting that CTGF antagonizes TGF; however, even when TGF is blocked, CTGF does not increase PSF, suggesting there is another mechanism antagonizing CTGF. We hypothesize that in addition to NKCC2, activation of Na/H exchanger (NHE) antagonizes CTGF, and when both are blocked CTGF dilates Af-Arts and this effect is blocked by a CTGF inhibitor benzamil. Using micropuncture, we studied the effects of transport inhibitors on TGF responses by measuring PSF while increasing nephron perfusion from 0 to 40 nl/min. Control TGF response (-7.9 ± 0.2 mmHg) was blocked by furosemide (-0.4 ± 0.2 mmHg; P < 0.001). Benzamil restored TGF in the presence of furosemide (furosemide: -0.2 ± 0.1 vs. furosemide+benzamil: -4.3 ± 0.3 mmHg; P < 0.001). With furosemide and NHE inhibitor, dimethylamiloride (DMA), increase in tubular flow increased PSF (furosemide+DMA: 2.7 ± 0.5 mmHg, n = 6), and benzamil blocked this (furosemide+DMA+benzamil: -1.1 ± 0.2 mmHg; P < 0.01, n = 6). We conclude that NHE in the nephron decreases PSF (Af-Art constriction) when NKCC2 and ENaC are inhibited, suggesting that in the absence of NKCC2, NHE causes a TGF response and that CTGF dilates the Af-Art when TGF is blocked with NKCC2 and NHE inhibitors.

  18. An in vivo microperfusion study of distal tubule bicarbonate reabsorption in normal and ammonium chloride rats.

    PubMed Central

    Levine, D Z

    1985-01-01

    For many years it has been thought that distal nephron hydrogen ion secretion can be importantly modulated by factors such as sodium delivery, sodium avidity, and potassium stores. Free flow micropuncture studies have also indicated that the rate of bicarbonate delivery may also alter the rate of bicarbonate reabsorption. The present studies were undertaken to examine possible luminal influences on total CO2 reabsorption in microperfused distal tubules in the rat in vivo. Tubules from normal and acidotic rats were perfused with five solutions in a manner that induced changes in bicarbonate load, sodium and potassium fluxes (JNa, JK), and luminal sulfate concentration. in each collected perfusate, simultaneous analyses were undertaken to determine water reabsorption, Na, and K concentrations using graphite furnace atomic absorption spectroscopy and total CO2 by microcalorimetry. Using factorial analysis of covariance to account for confounding effects on total CO2 flux (JtCO2) such as water reabsorption, distal tubules of acidotic rats reabsorbed CO2 in the range of 50-112 pmol X min-1 X mm-1 X These JtCO2 values were not significantly correlated with HCO3 load, JNa, or JK despite changes in the latter from net reabsorption to net secretion. Distal tubules of rats with normal acid-base status had JtCO2 values which were neither significantly different from zero nor correlated with changes in JK and JNa. Further, doubling the load from 250-500 pmol/min (by doubling the perfusion rate of 25-mM HCO3 solutions) did not stimulate JtCO2 in these normal animals. Accordingly, these acute in vivo microperfusion studies indicate for the first time that neither load nor potassium or sodium fluxes are important modulators of distal tubule bicarbonate reabsorption. PMID:2982915

  19. Homeostasis, the Milieu Intérieur, and the Wisdom of the Nephron

    PubMed Central

    Zeidel, Mark L.

    2014-01-01

    The concept of homeostasis has been inextricably linked to the function of the kidneys for more than a century when it was recognized that the kidneys had the ability to maintain the “internal milieu” and allow organisms the “physiologic freedom” to move into varying environments and take in varying diets and fluids. Early ingenious, albeit rudimentary, experiments unlocked a wealth of secrets on the mechanisms involved in the formation of urine and renal handling of the gamut of electrolytes, as well as that of water, acid, and protein. Recent scientific advances have confirmed these prescient postulates such that the modern clinician is the beneficiary of a rich understanding of the nephron and the kidney’s critical role in homeostasis down to the molecular level. This review summarizes those early achievements and provides a framework and introduction for the new CJASN series on renal physiology. PMID:24789550

  20. Nephron-sparing surgery in bilateral Wilms’ tumor: A report of two cases

    PubMed Central

    Arora, Sohrab; Kudchadkar, Sharmad; Yadav, Priyank; Ansari, M. S.

    2016-01-01

    Nephron-sparing surgery (NSS) has been proposed by many as an alternative to bilateral nephrectomies and renal replacement therapy in bilateral Wilms’ tumor (BWT). NSS is not without significant recurrence, morbidity, and mortality. Long-term follow-up, especially with regard to the renal function, remains lacking. Preoperative computed tomography angiogram can help prepare a roadmap for NSS but can underestimate the salvageable parenchyma due to compression of normal adjacent parenchyma. Intraoperative ultrasound can delineate the boundary of surgical margin and help achieve negative margins. We present two cases of BWT, aged 7 and 13 months, managed with neoadjuvant chemotherapy followed by bilateral NSS and adjuvant chemotherapy and report the follow-up of the same. We also explore the role of preoperative imaging and intraoperative ultrasound in the management. Both patients are alive without recurrence at a follow-up of 12 and 8 months. PMID:28057999

  1. Immunolocalization of hyperpolarization-activated cationic HCN1 and HCN3 channels in the rat nephron: regulation of HCN3 by potassium diets.

    PubMed

    López-González, Zinaeli; Ayala-Aguilera, Cosete; Martinez-Morales, Flavio; Galicia-Cruz, Othir; Salvador-Hernández, Carolina; Pedraza-Chaverri, José; Medeiros, Mara; Hernández, Ana Maria; Escobar, Laura I

    2016-01-01

    Hyperpolarization-activated cationic and cyclic nucleotide-gated channels (HCN) comprise four homologous subunits (HCN1-HCN4). HCN channels are found in excitable and non-excitable tissues in mammals. We have previously shown that HCN2 may transport ammonium (NH4 (+)), besides sodium (Na(+)), in the rat distal nephron. In the present work, we identified HCN1 and HCN3 in the proximal tubule (PT) and HCN3 in the thick ascending limb of Henle (TALH) of the rat kidney. Immunoblot assays detected HCN1 (130 kDa) and HCN3 (90 KDa) and their truncated proteins C-terminal HCN1 (93 KDa) and N-terminal HCN3 (65 KDa) in enriched plasma membranes from cortex (CX) and outer medulla (OM), as well as in brush-border membrane vesicles. Immunofluorescence assays confirmed apical localization of HCN1 and HCN3 in the PT. HCN3 was also found at the basolateral membrane of TALH. We evaluated chronic changes in mineral dietary on HCN3 protein abundance. Animals were fed with three different diets: sodium-deficient (SD) diet, potassium-deficient (KD) diet, and high-potassium (HK) diet. Up-regulation of HCN3 was observed in OM by KD and in CX and OM by HK; the opposite effect occurred with the N-terminal truncated HCN3 in CX (KD) and OM (HK). SD diet did not produce any change. Since HCN channels activate with membrane hyperpolarization, our results suggest that HCN channels may play a role in the Na(+)-K(+)-ATPase activity, contributing to Na(+), K(+), and acid-base homeostasis in the rat kidney.

  2. Distal gastrectomy versus total gastrectomy for distal gastric cancer

    PubMed Central

    Liu, Zhen; Feng, Fan; Guo, Man; Liu, Shushang; Zheng, Gaozan; Xu, Guanghui; Lian, Xiao; Fan, Daiming; Zhang, Hongwei

    2017-01-01

    Abstract Even though more than a century later, after the first case of gastrectomy has been successfully performed, the best surgical treatment for distal gastric cancer still remains controversial. Thus, the present study was designed to compare the survival impact of distal (DG) or total gastrectomy (TG) for distal gastric cancer. A total of 1262 distal gastric cancer patients were enrolled in current study including 1157 patients who underwent DG and 157 patients who underwent TG. The postoperative complications and 5-year overall survival were compared between the 2 groups. TG group presented a longer surgical time, a higher volume of intraoperative bleeding, and a larger number of excised lymph nodes (all P < 0.05) compared with the DG group. The postoperative complications were comparable (all P >0.05). The 5-year overall survival rate of DG group was significantly higher than that of TG group (67.6% vs 44.3%, P < 0.001). However, multivariate analysis showed that type of resection was not an independent prognostic factor for distal gastric cancer (P > 0.05). The factor-stratified multivariate analysis showed that only in the subgroup of Tumor-node-metastasis staging system (TNM) stage III (P = 0.049), TG was the independent prognostic factor for poor survival. In conclusion, DG was as feasible as TG; however, TG did not increase the survival rate. DG brought better long-term survival than TG in patients with TNM stage III tumor. We recommended that DG should be the optimal surgical procedure for distal gastric cancer under the premise of negative resection margin. PMID:28151896

  3. Traumatic Distal Ulnar Artery Thrombosis

    PubMed Central

    Karaarslan, Ahmet A.; Karakaşlı, Ahmet; Mayda, Aslan; Karcı, Tolga; Aycan, Hakan; Kobak, Şenol

    2014-01-01

    This paper is about a posttraumatic distal ulnar artery thrombosis case that has occurred after a single blunt trauma. The ulnar artery thrombosis because of chronic trauma is a frequent condition (hypothenar hammer syndrome) but an ulnar artery thrombosis because of a single direct blunt trauma is rare. Our patient who has been affected by a single blunt trauma to his hand and developed ulnar artery thrombosis has been treated by resection of the thrombosed ulnar artery segment. This report shows that a single blunt trauma can cause distal ulnar artery thrombosis in the hand and it can be treated merely by thrombosed segment resection in suitable cases. PMID:25276455

  4. Acute inhibition of NCC does not activate distal electrogenic Na+ reabsorption or kaliuresis

    PubMed Central

    Craigie, Eilidh; Homer, Natalie Z. M.; Mullins, John J.; Bailey, Matthew A.

    2014-01-01

    Na+ reabsorption from the distal renal tubule involves electroneutral and electrogenic pathways, with the latter promoting K+ excretion. The relative activities of these two pathways are tightly controlled, participating in the minute-to-minute regulation of systemic K+ balance. The pathways are interdependent: the activity of the NaCl cotransporter (NCC) in the distal convoluted tubule influences the activity of the epithelial Na+ channel (ENaC) downstream. This effect might be mediated by changes in distal Na+ delivery per se or by molecular and structural adaptations in the connecting tubule and collecting ducts. We hypothesized that acute inhibition of NCC activity would cause an immediate increase in Na+ flux through ENaC, with a concomitant increase in renal K+ excretion. We tested this using renal clearance methodology in anesthetized mice, by the administration of hydrochlorothiazide (HCTZ) and/or benzamil (BZM) to exert specific blockade of NCC and ENaC, respectively. Bolus HCTZ elicited a natriuresis that was sustained for up to 110 min; urinary K+ excretion was not affected. Furthermore, the magnitude of the natriuresis was no greater during concomitant BZM administration. This suggests that ENaC-mediated Na+ reabsorption was not normally limited by Na+ delivery, accounting for the absence of thiazide-induced kaliuresis. After dietary Na+ restriction, HCTZ elicited a kaliuresis, but the natiuretic effect of HCTZ was not enhanced by BZM. Our findings support a model in which inhibition of NCC activity does not increase Na+ reabsorption through ENaC solely by increasing distal Na+ delivery but rather by inducing a molecular and structural adaptation in downstream nephron segments. PMID:24402096

  5. Dissecting Stages of Human Kidney Development and Tumorigenesis with Surface Markers Affords Simple Prospective Purification of Nephron Stem Cells

    PubMed Central

    Pode-Shakked, Naomi; Pleniceanu, Oren; Gershon, Rotem; Shukrun, Rachel; Kanter, Itamar; Bucris, Efrat; Pode-Shakked, Ben; Tam, Gal; Tam, Hadar; Caspi, Revital; Pri-Chen, Sara; Vax, Einav; Katz, Guy; Omer, Dorit; Harari-Steinberg, Orit; Kalisky, Tomer; Dekel, Benjamin

    2016-01-01

    When assembling a nephron during development a multipotent stem cell pool becomes restricted as differentiation ensues. A faulty differentiation arrest in this process leads to transformation and initiation of a Wilms’ tumor. Mapping these transitions with respective surface markers affords accessibility to specific cell subpopulations. NCAM1 and CD133 have been previously suggested to mark human renal progenitor populations. Herein, using cell sorting, RNA sequencing, in vitro studies with serum-free media and in vivo xenotransplantation we demonstrate a sequential map that links human kidney development and tumorigenesis; In nephrogenesis, NCAM1+CD133− marks SIX2+ multipotent renal stem cells transiting to NCAM1+CD133+ differentiating segment-specific SIX2− epithelial progenitors and NCAM1−CD133+ differentiated nephron cells. In tumorigenesis, NCAM1+CD133− marks SIX2+ blastema that includes the ALDH1+ WT cancer stem/initiating cells, while NCAM1+CD133+ and NCAM1−CD133+ specifying early and late epithelial differentiation, are severely restricted in tumor initiation capacity and tumor self-renewal. Thus, negative selection for CD133 is required for defining NCAM1+ nephron stem cells in normal and malignant nephrogenesis. PMID:27020553

  6. [Fractures of the distal radius].

    PubMed

    Rueger, J M; Hartel, M J; Ruecker, A H; Hoffmann, M

    2014-11-01

    The most prevalent fractures managed by trauma surgeons are those involving the distal radius. The injury occurs in two peaks of prevalence: the first peak around the age of 10 years and the second peak around the age of 60 years. Distal radius fracture management requires sensitive diagnostics and classification. The objectives of treatment are the reconstruction of a pain-free unlimited durable functioning of the wrist and avoidance of typical fracture complications. Non-operative conservative management is generally employed for stable non-displaced fractures of the distal radius with the expectation of a good functional outcome. Unstable comminuted fractures with intra-articular and extra-articular fragment zones are initially set in a closed operation and finally by osteosynthesis. An armament of surgical implants is available for instable fractures requiring fixation. Palmar locked plate osteosynthesis has been established in recent years as the gold standard for operative management of distal radius fractures. Complex Working Group on Osteosynthesis (AO) classification type 3 fractures require extensive preoperative diagnostics to identify and treat typical associated injuries around the wrist.

  7. Oxalate mediated nephronal impairment and its inhibition by c-phycocyanin: a study on urolithic rats.

    PubMed

    Farooq, Shukkur Muhammed; Ebrahim, Abdul Shukkur; Subramhanya, Karthik Harve; Sakthivel, Ramasamy; Rajesh, Nachiappa Ganesh; Varalakshmi, Palaninathan

    2006-03-01

    The assumption of oxidative stress as a mechanism in oxalate induced renal damage suggests that antioxidants might play a beneficial role against oxalate toxicity. An in vivo model was used to investigate the effect of C-phycocyanin (from aquatic micro algae; Spirulina spp.), a known antioxidant, against calcium oxalate urolithiasis. Hyperoxaluria was induced in two of the 4 groups of Wistar albino rats (n = 6 in each) by intraperitoneally injecting sodium oxalate (70 mg/kg body weight). A pretreatment of phycocyanin (100 mg/kg body weight) as a single oral dosage was given, one hour prior to oxalate challenge. An untreated control and drug control (phycocyanin alone) were employed. Phycocyanin administration resulted in a significant improvement (p < 0.001) in the thiol content of renal tissue and RBC lysate via increasing glutathione and reducing malondialdehyde levels in the plasma of oxalate induced rats (p < 0.001), indicating phycocyanin's antioxidant effect on oxalate mediated oxidative stress. Administering phycocyanin after oxalate treatment significantly increased catalase and glucose-6-phosphate dehydrogenase activity (p < 0.001) in RBC lysate suggesting phycocyanin as a free radical quencher. Assessing calcium oxalate crystal retention in renal tissue using polarization microscopy and renal ultrastructure by electron microscopy reveals normal features in phycocyanin-- pretreated groups. Thus the study presents positive pharmacological implications of phycocyanin against oxalate mediated nephronal impairment and warrants further work to tap this potential aquatic resource for its medicinal application.

  8. [Distal radius fractures in children].

    PubMed

    Otayek, S; Ramanoudjame, M; Fitoussi, F

    2016-12-01

    Metaphyseal and physeal fractures of the distal radius are common in children. Most cases are best treated with closed reduction and cast immobilization. Long-term outcomes of these injuries are excellent when specific treatment principles of reduction and casting are followed. Surgical indications are limited and include open fractures, intra-articular fractures, non-reducible fractures, unstable fractures, and the presence of associated nerve injury. Closed reduction and percutaneous pin fixation is the most commonly used surgical option. The clinician should be aware of delayed complications such as growth disturbance of the distal radius, and understand how to manage these problems to ensure successful long-term outcomes. Epiphysiodesis is uncommon but growth plate injuries need to be followed for one year.

  9. Distal clavicle fractures in children☆

    PubMed Central

    Labronici, Pedro José; da Silva, Ricardo Rodrigues; Franco, Marcos Vinícius Viana; Labronici, Gustavo José; Pires, Robinson Esteves Santos; Franco, José Sergio

    2015-01-01

    Objective To analyze fractures of the distal clavicle region in pediatric patients. Methods Ten patients between the ages of five to eleven years (mean of 7.3 years) were observed. Nine patients were treated conservatively and one surgically. All the fractures were classified using the Nenopoulos classification system. Results All the fractures consolidated without complications. Conservative treatment was used for nine patients, of whom three were in group IIIB, three IIb, two IIa and one IV. The only patient who was treated surgically was a female patient of eleven years of age with a group IV fracture. Conclusion The treatment indication for distal fractures of the clavicle in children should be based on the patient's age and the displacement of the fragments. PMID:26962489

  10. Distal esophageal spasm: an update.

    PubMed

    Achem, Sami R; Gerson, Lauren B

    2013-09-01

    Distal esophageal spasm (DES) is an esophageal motility disorder that presents clinically with chest pain and/or dysphagia and is defined manometrically as simultaneous contractions in the distal (smooth muscle) esophagus in ≥20% of wet swallows (and amplitude contraction of ≥30 mmHg) alternating with normal peristalsis. With the introduction of high resolution esophageal pressure topography (EPT) in 2000, the definition of DES was modified. The Chicago classification proposed that the defining criteria for DES using EPT should be the presence of at least two premature contractions (distal latency<4.5 s) in a context of normal EGJ relaxation. The etiology of DES remains insufficiently understood, but evidence links nitric oxide (NO) deficiency as a culprit resulting in a disordered neural inhibition. GERD frequently coexists in DES, and its role in the pathogenesis of symptoms needs further evaluation. There is some evidence from small series that DES can progress to achalasia. Treatment remains challenging due in part to lack of randomized placebo-controlled trials. Current treatment agents include nitrates (both short and long acting), calcium-channel blockers, anticholinergic agents, 5-phosphodiesterase inhibitors, visceral analgesics (tricyclic agents or SSRI), and esophageal dilation. Acid suppression therapy is frequently used, but clinical outcome trials to support this approach are not available. Injection of botulinum toxin in the distal esophagus may be effective, but further data regarding the development of post-injection gastroesophageal reflux need to be assessed. Heller myotomy combined with fundoplication remains an alternative for the rare refractory patient. Preliminary studies suggest that the newly developed endoscopic technique of per oral endoscopic myotomy (POEM) may also be an alternative treatment modality.

  11. Endoscopic Distal Tibiofibular Syndesmosis Arthrodesis.

    PubMed

    Lui, Tun Hing

    2016-04-01

    Chronic distal tibiofibular syndesmosis disruption can be managed by endoscopic arthrodesis of the syndesmosis. This is performed through the proximal anterolateral and posterolateral portals. The scar tissue and bone block are resected to facilitate the subsequent reduction of the syndesmosis. The reduction of the syndesmosis can be guided either arthroscopically or endoscopically. The tibial and fibular surfaces of the tibiofibular overlap can be microfractured to facilitate subsequent fusion.

  12. Zero ischaemia laparoscopic nephron-sparing surgery by re-suturing

    PubMed Central

    Lu, Jinshan; Zu, Qiang; Du, Qingshan; Xu, Yong; Zhang, Xu

    2014-01-01

    Aim of the study To report a pre-suture technique in laparoscopic nephron-sparing surgery (LNSS), which could help reduce and even avoid ischaemia for the treatment of renal cell carcinoma. Material and methods Between January and June 2013 we treated 14 patients presenting with renal tumours. The mean age was 46 years and average tumour size was 2.4 cm in diameter determined by computed tomography (CT). All the patients were treated with LNSS by pre-suturing the resection. Results In 13 out of the 14 cases, no clamping was needed during the whole surgery processes, i.e. zero ischaemia was achieved. In the other case, the renal artery was clamped for only 150 seconds due to suture avulsion. The mean operating time was 75 minutes (range 50 to 110 minutes) and mean blood loss was 60 ml (range 30 to 200 ml). After removal of the drain 2–3 days after surgery, the average postoperative hospital stay time was four days. The surgery had only a minor effect on the renal function. No case of urinary leakage or postoperative bleeding occurred. Postoperative pathological reports showed that the tumours were resected completely with negative surgical margins for all cases. There were no signs of recurrence on follow-up CT performed 1–6 months after surgery. Conclusions The pre-suture technique in LNSS reported here required zero or minimal ischaemia time and hence avoided renal ischaemia-reperfusion injury. This surgical technique could be a feasible surgical option for treatment of small, exophytic and peripheral renal tutors. PMID:25477760

  13. Laparoscopic Retroperitoneal Nephron-Sparing Surgery Without Renal Artery Clamping with Preoperative Selective Arterial Embolization for Management of Right Renal Angiomyolipoma of Diameter 10 cm: A Case Report

    PubMed Central

    Hoshii, Tatsuhiko; Morita, Shinichi; Ikeda, Yohei; Hasegawa, Go

    2017-01-01

    Abstract A 38-year-old female without the tuberous sclerosis complex was diagnosed with right renal angiomyolipoma of 10 cm in diameter. She underwent laparoscopic retroperitoneal nephron-sparing surgery without renal artery clamping with preoperative selective arterial embolization to avoid a significant risk of hemorrhage and the damage of the renal function during nephron-sparing surgery. The tumor was resected completely. The time taken to complete the procedure was 4 hours 11 minutes and blood loss was 780 mL. She was transfused 400 mL of autologous blood. PMID:28265590

  14. Phenotyping by magnetic resonance imaging nondestructively measures glomerular number and volume distribution in mice with and without nephron reduction

    PubMed Central

    Baldelomar, Edwin J.; Charlton, Jennifer R.; Beeman, Scott C.; Hann, Bradley D.; Cullen-McEwen, Luise; Pearl, Valeria M.; Bertram, John F.; Wu, Teresa; Zhang, Min; Bennett, Kevin M.

    2015-01-01

    Reduced nephron mass is strongly linked to susceptibility to chronic renal and cardiovascular diseases. There are currently no tools to identify nephropenia in clinical or preclinical diagnostics. Such new methods could uncover novel mechanisms and therapies for chronic kidney disease (CKD) and reveal how variation among traits can affect renal function and morphology. Here we used cationized ferritin (CF) enhanced-MRI (CFE-MRI) to investigate the relationship between glomerular number (Nglom) and volume (Vglom) in kidneys of healthy wild type mice and mice with oligosyndactylism (Os/+), a model of congenital nephron reduction. Mice were injected with cationic ferritin and perfused and the resected kidneys imaged with 7T MRI to detect CF-labeled glomeruli. CFE-MRI was used to measure the intrarenal distribution of individual glomerular volumes and revealed two major populations of glomeruli distinguished by size. Spatial mapping revealed that the largest glomeruli were located in the juxtamedullary region in both wild type and Os/+ mice and the smallest population located in the cortex. Os/+ mice had about a 50% reduction and 35% increase of Nglom and Vglom, respectively, in both glomerular populations compared to wild type, consistent with glomerular hypertrophy in the Os/+ mice. Thus, we provide a foundation for whole-kidney, MRI-based phenotyping of mouse renal glomerular morphology and provide new potential for quantitative human renal diagnostics. PMID:26535998

  15. Microcyst formation and HIV-1 gene expression occur in multiple nephron segments in HIV-associated nephropathy.

    PubMed

    Ross, M J; Bruggeman, L A; Wilson, P D; Klotman, P E

    2001-12-01

    Tubular microcyst formation is a prominent histopathologic feature of HIV-associated nephropathy (HIVAN), but its pathogenesis is unknown. HIV-1 has recently been shown to infect renal tubular epithelial cells in patients with HIVAN. In addition, HIV-1 gene expression in renal epithelial cells has been shown to cause a renal disease that is identical to HIVAN in HIV-1 transgenic mice. In these studies, immunohistochemistry for tubular segment-specific markers and mRNA in situ hybridization for HIV-1 was used to determine which tubular segments develop microcysts and which segments express HIV-1 in the kidneys of transgenic mice and patients with HIVAN. It was found that microcysts involve multiple nephron segments in both patients with HIVAN and HIV-1 transgenic mice. Furthermore, HIV-1 infection in HIVAN and HIV-1 transgene expression also occurs in multiple segments of the nephron. These data support a direct role for HIV-1 infection of renal epithelial cells in the pathogenesis of microcyst formation in patients with HIVAN.

  16. Cellular interactions via conditioned media induce in vivo nephron generation from tubular epithelial cells or mesenchymal stem cells.

    PubMed

    Machiguchi, Toshihiko; Nakamura, Tatsuo

    2013-06-07

    There are some successful reports of kidney generation by utilizing the natural course of kidney development, namely, the use of an artificially treated metanephros, blastocyst or ureteric bud. Under a novel concept of cellular interactions via conditioned media (CMs), we have attempted in vivo nephron generation from tubular epithelial cells (TECs) or mesenchymal stem cells (MSCs). Here we used 10× CMs of vascular endothelial cells (VECs) and TECs, which is the first to introduce a CM into the field of organ regeneration. We first present stimulative cross-talks induced by these CMs between VECs and TECs on cell proliferation and morphological changes. In MSCs, TEC-CM suppressed these changes, however, induced cytokeratin expression, indicating the differentiation of MSCs into TECs. As a result, glomerular and tubular structures were created following the implantation of TECs or MSCs with both CMs. Our findings suggest that the cellular interactions via CMs might induce in vivo nephron generation from TECs or MSCs. As a promoting factor, CMs could also be applied to the regeneration of other organs and tissues.

  17. Distal realignment (tibial tuberosity transfer).

    PubMed

    Feller, Julian Ashley

    2012-09-01

    Although tibial tuberosity (TT) transfer has for many years been the basis of many protocols for the management of patellar instability, the role of pure medial transfer in particular appears to be declining. In contrast, the greater recognition of the importance of patella alta as a predisposing factor to recurrent patellar dislocation has resulted in a resurgence in the popularity of distal TT transfer. When TT transfer is performed, the direction and amount of transfer is based on the patellar height and the lateralization of the TT relative to the trochlear groove. Patellar height is best assessed on a lateral radiograph with the knee in flexion using a ratio that uses the articular surface of the patella in relation to the height above the tibia. Assessment of lateralization of the TT relative to the trochlear groove can be made using either computed tomography or magnetic resonance imaging scans.

  18. Regulation of renal potassium secretion: molecular mechanisms.

    PubMed

    Welling, Paul A

    2013-05-01

    A new understanding of renal potassium balance has emerged as the molecular underpinnings of potassium secretion have become illuminated, highlighting the key roles of apical potassium channels, renal outer medullary potassium channel (ROMK) and Big Potassium (BK), in the aldosterone-sensitive distal nephron and collecting duct. These channels act as the final-regulated components of the renal potassium secretory machinery. Their activity, number, and driving forces are precisely modulated to ensure potassium excretion matches dietary potassium intake. Recent identification of the underlying regulatory mechanisms at the molecular level provides a new appreciation of the physiology and reveals a molecular insight to explain the paradoxic actions of aldosterone on potassium secretion. Here, we review the current state of knowledge in the field.

  19. Direct Activation of ENaC by Angiotensin II: Recent Advances and New Insights

    PubMed Central

    Zaika, Oleg; Mamenko, Mykola; Staruschenko, Alexander

    2012-01-01

    Angiotensin II (Ang II) is the principal effector of the renin-angiotensin-aldosterone system (RAAS). It initiates myriad processes in multiple organs integrated to increase circulating volume and elevate systemic blood pressure. In the kidney, Ang II stimulates renal tubular water and salt reabsorption causing antinatriuresis and antidiuresis. Activation of RAAS is known to enhance activity of the epithelial Na+ channel (ENaC) in the aldosterone-sensitive distal nephron. In addition to its well described stimulatory actions on aldosterone secretion, Ang II is also capable to directly increase ENaC activity. In this brief review, we discuss recent findings about non-classical Ang II actions on ENaC and speculate about its relevance for renal sodium handling. PMID:23180052

  20. New molecular players facilitating Mg(2+) reabsorption in the distal convoluted tubule.

    PubMed

    Glaudemans, Bob; Knoers, Nine V A M; Hoenderop, Joost G J; Bindels, René J M

    2010-01-01

    The renal distal convoluted tubule (DCT) has an essential role in maintaining systemic magnesium (Mg(2+)) concentration. The DCT is the final determinant of plasma Mg(2+) levels, as the more distal nephron segments are largely impermeable to Mg(2+). In the past decade, positional candidate strategies in families with inherited forms of hypomagnesemia have led to the identification of genes involved in Mg(2+) handling. A large fraction of this resides in the DCT, namely, (i) the transient receptor potential channel melastatin subtype 6 (TRPM6), a divalent cation-permeable channel located at the luminal membrane of the DCT, facilitates Mg(2+) entry from the pro-urine into the cell; (ii) the epidermal growth factor is a novel hormone regulating active Mg(2+) transport through TRPM6; (iii) the voltage-gated K(+) channel, Kv1.1, establishes a favorable luminal membrane potential for TRPM6-mediated Mg(2+) transport; (iv) the Na(+)/K(+)-ATPase gamma-subunit (gamma-Na(+)/K(+)-ATPase) was identified as mutated protein in a family with isolated dominant hypomagnesemia. The molecular mechanism by which gamma-Na(+)/K(+)-ATPase is involved in DCT Mg(2+) handling remains unknown; (v) a high percentage of patients with mutations in the renal transcription factor HNF1B (hepatocyte nuclear factor 1 homeobox B) gene develop hypomagnesemia; and (vi) Gitelman and EAST/SeSAME syndrome patients suffer from a similar tubulopathy due to mutations in NCC (NaCl cotransporter) and Kir4.1, respectively. In these patients, decreased expression of TRPM6 is proposed to cause hypomagnesemia. Insights into the molecular mechanisms of the identified genes, as well as the identification of novel genes, will further improve our knowledge about renal Mg(2+) handling.

  1. Preferential Propagation of Competent SIX2+ Nephronic Progenitors by LIF/ROCKi Treatment of the Metanephric Mesenchyme.

    PubMed

    Tanigawa, Shunsuke; Sharma, Nirmala; Hall, Michael D; Nishinakamura, Ryuichi; Perantoni, Alan O

    2015-09-08

    Understanding the mechanisms responsible for nephrogenic stem cell preservation and commitment is fundamental to harnessing the potential of the metanephric mesenchyme (MM) for nephron regeneration. Accordingly, we established a culture model that preferentially expands the MM SIX2+ progenitor pool using leukemia inhibitory factor (LIF), a Rho kinase inhibitor (ROCKi), and extracellular matrix. Passaged MM cells express the key stem cell regulators Six2 and Pax2 and remain competent to respond to WNT4 induction and form mature tubular epithelia and glomeruli. Mechanistically, LIF activates STAT, which binds to a Stat consensus sequence in the Six2 proximal promoter and sustains SIX2 levels. ROCKi, on the other hand, attenuates the LIF-induced differentiation activity of JNK. Concomitantly, the combination of LIF/ROCKi upregulates Slug expression and activates YAP, which maintains SIX2, PAX2, and SALL1. Using this novel model, our study underscores the pivotal roles of SIX2 and YAP in MM stem cell stability.

  2. Nephron sparing endoscopic treatment for primary carcinoma of the renal calyx: A case report and literature review

    PubMed Central

    WANG, QI; OU, TONG-WEN; XU, JIA-WEI; LI, JIN; BORAZJANI, ALI; JIA, CHUN-SONG; WANG, XU; YAN, HAO

    2016-01-01

    Primary carcinoma of the renal calyx is extremely rare. The present study reported nephron sparing endoscopic treatment for primary carcinoma of the renal calyx. An 81-year-old female presented with a 1-year history of intermittent painless gross hematuria. Computed tomography and X-ray of the urinary tract were unable to definitively identify any lesion. Flexible ureteroscopic examination revealed a tumor with epicenter in the lower calyx of the right kidney, with additional involvement around the calyx. Biopsies were obtained and pathology revealed low-grade urothelial carcinoma. Considering additional co-morbidities, the patient elected to undergo endoscopic management with thulium laser. The present report described the feasibility of flexible ureteroscopic thulium laser resection for the treatment of renal calyx carcinoma. PMID:27330785

  3. Six2 and Wnt regulate self-renewal and commitment of nephron progenitors through shared gene regulatory networks

    PubMed Central

    Park, Joo-Seop; Ma, Wenxiu; O’Brien, Lori L.; Chung, Eunah; Guo, Jin-Jin; Cheng, Jr-Gang; Valerius, M. Todd; McMahon, Jill A.; Wong, Wing Hung; McMahon, Andrew P.

    2014-01-01

    SUMMARY A balance between Six2-dependent self-renewal and canonical Wnt signaling-directed commitment regulates mammalian nephrogenesis. Intersectional studies using chromatin immunoprecipitation and transcriptional profiling identified direct target genes shared by each pathway within nephron progenitors. Wnt4 and Fgf8 are essential for progenitor commitment; cis-regulatory modules flanking each gene are co-bound by Six2 and β-catenin, and dependent on conserved Lef/Tcf binding sites for activity. In vitro and in vivo analyses suggest that Six2 and Lef/Tcf factors form a regulatory complex that promotes progenitor maintenance while entry of β-catenin into this complex promotes nephrogenesis. Alternative transcriptional responses associated with Six2 and β-catenin co-binding events occur through non-Lef/Tcf DNA binding mechanisms highlighting the regulatory complexity downstream of Wnt signaling in the developing mammalian kidney. PMID:22902740

  4. Cell-specific regulation of L-WNK1 by dietary K+

    PubMed Central

    Webb, Tennille N.; Carrisoza-Gaytan, Rolando; Montalbetti, Nicolas; Rued, Anna; Roy, Ankita; Socovich, Alexandra M.; Subramanya, Arohan R.; Satlin, Lisa M.; Carattino, Marcelo D.

    2015-01-01

    Flow-induced K+ secretion in the aldosterone-sensitive distal nephron is mediated by high-conductance Ca2+-activated K+ (BK) channels. Familial hyperkalemic hypertension (pseudohypoaldosteronism type II) is an inherited form of hypertension with decreased K+ secretion and increased Na+ reabsorption. This disorder is linked to mutations in genes encoding with-no-lysine kinase 1 (WNK1), WNK4, and Kelch-like 3/Cullin 3, two components of an E3 ubiquitin ligase complex that degrades WNKs. We examined whether the full-length (or “long”) form of WNK1 (L-WNK1) affected the expression of BK α-subunits in HEK cells. Overexpression of L-WNK1 promoted a significant increase in BK α-subunit whole cell abundance and functional channel expression. BK α-subunit abundance also increased with coexpression of a kinase dead L-WNK1 mutant (K233M) and with kidney-specific WNK1 (KS-WNK1), suggesting that the catalytic activity of L-WNK1 was not required to increase BK expression. We examined whether dietary K+ intake affected L-WNK1 expression in the aldosterone-sensitive distal nephron. We found a paucity of L-WNK1 labeling in cortical collecting ducts (CCDs) from rabbits on a low-K+ diet but observed robust staining for L-WNK1 primarily in intercalated cells when rabbits were fed a high-K+ diet. Our results and previous findings suggest that L-WNK1 exerts different effects on renal K+ secretory channels, inhibiting renal outer medullary K+ channels and activating BK channels. A high-K+ diet induced an increase in L-WNK1 expression selectively in intercalated cells and may contribute to enhanced BK channel expression and K+ secretion in CCDs. PMID:26662201

  5. Genetics Home Reference: distal hereditary motor neuropathy, type II

    MedlinePlus

    ... distal hereditary motor neuropathy, type II distal hereditary motor neuropathy, type II Enable Javascript to view the ... PDF Open All Close All Description Distal hereditary motor neuropathy, type II is a progressive disorder that ...

  6. Elbow dislocation with ipsilateral distal radius fracture

    PubMed Central

    Meena, Sanjay; Trikha, Vivek; Kumar, Rakesh; Saini, Pramod; Sambharia, Abhishek Kumar

    2013-01-01

    Elbow dislocation associated with ipsilateral distal radius fracture is a rare pattern of injury, although it is common for elbow dislocation and forearm fractures to occur separately. We report a rare case of a 20-year-old male who had a posterior elbow dislocation and ipsilateral distal radius fracture. Elbow dislocation was first reduced in extension and distal radius fracture was then reduced in flexion. Both the injuries were conservatively managed. At 6 months follow-up, the patient had no pain in his elbow and minimal pain in his wrist on heavy lifting and had resumed his work as a laborer. PMID:24082758

  7. Elbow dislocation with ipsilateral distal radius fracture.

    PubMed

    Meena, Sanjay; Trikha, Vivek; Kumar, Rakesh; Saini, Pramod; Sambharia, Abhishek Kumar

    2013-07-01

    Elbow dislocation associated with ipsilateral distal radius fracture is a rare pattern of injury, although it is common for elbow dislocation and forearm fractures to occur separately. We report a rare case of a 20-year-old male who had a posterior elbow dislocation and ipsilateral distal radius fracture. Elbow dislocation was first reduced in extension and distal radius fracture was then reduced in flexion. Both the injuries were conservatively managed. At 6 months follow-up, the patient had no pain in his elbow and minimal pain in his wrist on heavy lifting and had resumed his work as a laborer.

  8. Management of Complications of Distal Radius Fractures

    PubMed Central

    Chung, Kevin C.; Mathews, Alexandra L.

    2015-01-01

    Synopsis Treating a fracture of the distal radius may require the surgeon to make a difficult decision between surgical treatment and nonsurgical management. The use of surgical fixation has recently increased owing to complications associated with conservative treatment. However, conservative action may be necessary depending on certain patient factors. The treating surgeon must be aware of the possible complications associated with distal radius fracture treatments to prevent their occurrence. Prevention can be achieved with a proper understanding of the mechanism of these complications. This article discusses the most recent evidence on how to manage and prevent complications following a fracture of the distal radius. PMID:25934197

  9. Semiconstrained Distal Radioulnar Joint Prosthesis

    PubMed Central

    Savvidou, Christiana; Murphy, Erin; Mailhot, Emilie; Jacob, Shushan; Scheker, Luis R.

    2013-01-01

    Distal radioulnar joint (DRUJ) problems can occur as a result of joint instability, abutment, or incongruity. The DRUJ is a weight-bearing joint; the ulnar head is frequently excised either totally or partially, and in some cases it is fused, because of degenerative, rheumatoid, or posttraumatic arthritis. Articles about these procedures report the ability to pronate and supinate, but they rarely discuss grip strength, and even less do they address lifting capacity. We report the long term results of the first 35 patients who underwent total DRUJ arthroplasty with the Aptis DRUJ prosthesis after 5 years follow-up. Surgical indications were all causes of dysfunctional DRUJ (degenerative, posttraumatic, autoimmune, congenital). We recorded data for patient demographics, range of motion (ROM), strength, and lifting capacity of the operated and of the nonoperated extremity. Pain and functional assessments were also recorded. The Aptis DRUJ prosthesis, a bipolar self-stabilizing DRUJ endoprosthesis that restores forearm function, consists of a semiconstained and modular implant designed to replace the function of the ulnar head, the sigmoid notch of the radius, and the triangular fibrocartilage ligaments. The surgical technique is presented in detail. The majority of the patients regained adequate ROM and improved their strength and lifting capacity to the operated side. Pain and activities of daily living were improved. Twelve patients experienced complications, most commonly being extensor carpi ulnaris (ECU) tendinitis, ectopic bone formation, bone resorption with stem loosening, low-grade infection, and need for ball replacement. The Aptis total DRUJ replacement prosthesis is an alternative to salvage procedures that enables a full range of motion as well as the ability to grip and lift weights encountered in daily living activities. PMID:24436788

  10. Villous adenoma of the distal appendix.

    PubMed

    Taylor, J V; Thomas, M G; Kelly, S; Sutton, R

    1997-04-01

    Villous adenoma confined to the distal appendix has not been previously reported in conjunction with acute apendicitis. The presence of an adenoma indicates a need for further investigation due to an association with neoplasia elsewhere.

  11. Genetics Home Reference: Laing distal myopathy

    MedlinePlus

    ... Laing distal myopathy is a condition that affects skeletal muscles, which are muscles that the body uses for ... in heart (cardiac) muscle and in type I skeletal muscle fibers. Type I fibers, which are also known ...

  12. Distinct distribution of specific members of protein 4.1 genefamily in the mouse nephron

    SciTech Connect

    Ramez, Mohamed; Blot-Chabaud, Marcel; Cluzeaud, Francoise; Chanan, Sumita; Patterson, Michael; Walensky, Loren D.; Marfatia, Shirin; Baines, Anthony J.; Chasis, Joel A.; Conboy, John G.; Mohandas, Narla; Gascard, Philippe

    2002-12-11

    Background: Protein 4.1 is an adapter protein which linksthe actin cytoskeleton to various transmembrane proteins. 4.1 proteinsare encoded by four homologous genes, 4.1R, 4.1G, 4.1N, and 4.1B, whichundergo complex alternative splicing. Here we performed a detailedcharacterization of the expression of specific 4.1 proteins in the mousenephron. Methods: Distribution of renal 4.1 proteins was investigated bystaining of paraformaldehyde fixed mouse kidney sections with antibodieshighly specific for each 4.1 protein. Major 4.1 splice forms, amplifiedfrom mouse kidney marathon cDNA, were expressed in transfected COS-7cells in order to assign species of known exon composition to proteinsdetected in kidney. Results: A 105kDa4.1R splice form, initiating atATG-2 translation initiation site and lacking exon 16, but including exon17B, was restricted to thick ascending limb of Henle's loop. A 95kDa 4.1Nspliceform,lacking exons 15 and 17D, was expressed in either descendingor ascending thin limb of Henle'sloop, distal convoluted tubule and allregions of the collecting duct system. A major 108kDa 4.1B spliceform,initiating at a newly characterized ATG translation initiation site, andlacking exons 15, 17B, and 21, was present only in Bowman's capsule andproximal convoluted tubule (PCT). There was no expression of 4.1G inkidney. Conclusion: Distinct distribution of 4.1 proteins along thenephron suggests their involvement in targeting of selected transmembraneproteins in kidney epithelium andtherefore in regulation of specifickidney functions.

  13. Sodium-pump gene-expression, protein abundance and enzyme activity in isolated nephron segments of the aging rat kidney

    PubMed Central

    Scherzer, Pnina; Gal-Moscovici, Anca; Sheikh-Hamad, David; Popovtzer, Mordecai M

    2015-01-01

    Aging is associated with alteration in renal tubular functions, including sodium handling and concentrating ability. Na-K-ATPase plays a key role in driving tubular transport, and we hypothesized that decreased concentrating ability of the aging kidney is due in part to downregulation of Na-K-ATPase. In this study, we evaluated Na and K balance, aldosterone levels, and Na-K-ATPase gene expression, protein abundance, and activity in aging rat kidney. Na-K-ATPase activity (assayed microfluorometrically), mRNA (RT-PCR), and protein abundance (immunoblotting) were quantitated in the following isolated nephron segments: PCT, PST, MTAL, DCT, and CCD from 2, 8, 15, and 24 month-old-rats. In the course of aging, creatinine clearance decreased from 0.48 ± 0.02 mL/min/100 g BW to 0.28 ± 0.06 (P < 0.001) and aldosterone decreased from 23.6 ± 0.8 ng/dL to 13.2 ± 0.6 (P < 0.001). Serum Na+ and K+ increased by 4.0% and 22.5%, respectively. Na-K-ATPase activity, mRNA, and protein abundance of the α1 subunit displayed similar trends in all assayed segments; increasing in PCT and PST; decreasing in MTAL and DCT; increasing in CCD: in PCT they increased by 40%, 75%, and 250%, respectively; while in PST they increased by 80%, 50%, and 100%, respectively (P < 0.001). In MTAL they declined by 36%, 24%, and 34%, respectively, and in DCT by 38%, 59%, and 60%, respectively (P < 0.001). They were higher in CCD by 110%, 115%, and 246%, respectively (P < 0.001). Rats maintained Na/K balance; however with a steady state elevated serum K+. These results reveal quantitative changes in axial distribution of Na-K-ATPase at the level of gene expression, protein abundance, and activity in the nephrons of aging animals and may explain, in part, the pathophysiology of the senescent kidney. PMID:26056060

  14. Sextant of Sapphires for Molar Distalization

    PubMed Central

    Palla, Yudistar Venkata; Ganugapanta, Vivek Reddy

    2016-01-01

    Introduction Space analysis quantifies the amount of crowding within the arches estimating the severity of space discrepancy. The space gaining procedures include extraction and non-extraction procedures like expansion, proximal stripping and molar distalization. Aim To identify features seen in molar distalization cases. Materials and Methods The sample size comprised 20 patients in whom molar distalization was decided as the treatment plan. The study models and lateral cephalograms of all the patients were taken. Occlusograms were obtained. Model analysis and cephalometric analysis were performed. Descriptive statistical analysis like mean, standard deviation, standard error and mode were done. Results The parameters in Question gave following results. The Bolton analysis showed anterior mandibular excess with mean value of 1.56mm±1.07. The first order discrepancy between maxillary central and lateral incisors was 5±1.95. The premolar rotation showed mean value of 16.58±5.12. The molar rotation showed the value of 7.66±2.26. The nasolabial angle showed the mean of 101.25±8.7 IMPA of 101.4±5.74. Conclusion The six features studied in molar distalization cases [First order discrepancy between upper central and lateral incisors; Rotation of premolars and molars; Bolton’s discrepancy in anterior dentition; Average to horizontal growth pattern; Proclined lower incisors and Obtuse nasolabial angle] can be taken as patterns seen in molar distalization cases and considered as a valid treatment plan. PMID:27656572

  15. Topographic matching of distal radius and proximal fibula articular surface for distal radius osteoarticular reconstruction.

    PubMed

    Zhang, H; Chen, S; Wang, Z; Guo, Y; Liu, B; Tong, D

    2016-07-01

    During osteoarticular reconstruction of the distal radius with the proximal fibula, congruity between the two articular surfaces is an important factor in determining the quality of the outcome. In this study, a three-dimensional model and a coordinate transformation algorithm were developed on computed tomography scanning. Articular surface matching was performed and parameters for the optimal position were determined quantitatively. The mean radii of best-fit spheres of the articular surfaces of the distal radius and proximal fibula were compared quantitatively. The radial inclination and volar tilt following reconstruction by an ipsilateral fibula graft, rather than the contralateral, best resembles the values of the native distal radius. Additionally, the ipsilateral fibula graft reconstructed a larger proportion of the distal radius articular surface than did the contralateral. The ipsilateral proximal fibula graft provides a better match for the reconstruction of the distal radius articular surface than the contralateral, and the optimal position for graft placement is quantitatively determined.

  16. Polymerase chain reaction localization of constitutive nitric oxide synthase and soluble guanylate cyclase messenger RNAs in microdissected rat nephron segments.

    PubMed Central

    Terada, Y; Tomita, K; Nonoguchi, H; Marumo, F

    1992-01-01

    Stimulation of the release of nitric oxide (NO) in the kidney has been shown to result in renal hemodynamic changes and natriuresis. NO is a potent stimulator of soluble guanylate cyclase, leading to an increase of cyclic GMP. The precise localization of NO synthase and soluble guanylate cyclase in the renal structure is not known. In this study, the microlocalization of mRNAs coding for constitutive NO synthase and soluble guanylate cyclase was carried out in the rat kidney, using an assay of reverse transcription and polymerase chain reaction in individual microdissected renal tubule segments along the nephron, glomeruli, vasa recta bundle, and arcuate arteries. A large signal for constitutive NO synthase was detected in inner medullary collecting duct. Small signals were detected in inner medullary thin limb, cortical collecting duct, outer medullary collecting duct, glomerulus, vasa recta, and arcuate artery. Soluble guanylate cyclase mRNA is expressed largely in glomerulus, proximal convoluted tubule, proximal straight tubule, and cortical collecting duct, and in small amounts in medullary thick ascending limb, inner medullary thin limb, outer medullary collecting duct, inner medullary collecting duct, and the vascular system. Our data demonstrate that NO can be produced locally in the kidney, and that soluble guanylate cyclase is widely distributed in glomerulus, renal tubules, and the vascular system. Images PMID:1379616

  17. Preferential Propagation of Competent SIX2+ Nephronic Progenitors by LIF/ROCKi Treatment of the Metanephric Mesenchyme

    PubMed Central

    Tanigawa, Shunsuke; Sharma, Nirmala; Hall, Michael D.; Nishinakamura, Ryuichi; Perantoni, Alan O.

    2015-01-01

    Summary Understanding the mechanisms responsible for nephrogenic stem cell preservation and commitment is fundamental to harnessing the potential of the metanephric mesenchyme (MM) for nephron regeneration. Accordingly, we established a culture model that preferentially expands the MM SIX2+ progenitor pool using leukemia inhibitory factor (LIF), a Rho kinase inhibitor (ROCKi), and extracellular matrix. Passaged MM cells express the key stem cell regulators Six2 and Pax2 and remain competent to respond to WNT4 induction and form mature tubular epithelia and glomeruli. Mechanistically, LIF activates STAT, which binds to a Stat consensus sequence in the Six2 proximal promoter and sustains SIX2 levels. ROCKi, on the other hand, attenuates the LIF-induced differentiation activity of JNK. Concomitantly, the combination of LIF/ROCKi upregulates Slug expression and activates YAP, which maintains SIX2, PAX2, and SALL1. Using this novel model, our study underscores the pivotal roles of SIX2 and YAP in MM stem cell stability. PMID:26321142

  18. Fabrication and Evaluation of a Noncompliant Molar Distalizing Appliance: Bonded Molar Distalizer

    PubMed Central

    Sodagar, A.; Ahmad Akhoundi, M. S.; Rafighii, A.; Arab, S.

    2011-01-01

    Objective Attempts to treat class II malocclusions without extraction in non-compliant patients have led to utilization of intraoral molar distalizing appliances. The purpose of this study was to investigate dental and skeletal effects of Bonded Molar Distalizer (BMD) which is a simple molar distalizing appliance. Materials and Methods Sixteen patients (12 girls, four boys) with bilateral half-cusp class II molar relationship, erupted permanent second molars and normal or vertical growth pattern were selected for bilateral distalization of maxillary molars via BMD. The screws were activated every other day, alternately. Lateral cephalograms and study models were obtained before treatment and after 11 weeks activation of the appliance. Results Significant amounts of molar distalization, molar distal tipping and anchorage loss were observed. The mean maxillary first molar distal movement was 1.22±0.936 mm with a distal tipping of 2.97±3.74 degrees in 11 weeks. The rate of distal movement was 0.48 mm per month. Reciprocal mesial movement of the first premolars was 2.26±1.12 mm with a mesial tipping of 4.25±3.12 degrees. Maxillary incisors moved 3.55±1.46 mm and tipped 9.87±5.03 degrees mesially. Lower anterior face height (LAFH) decreased 1.28±1.36 mm. Conclusion BMD is appropriate for distalizing maxillary molars, especially in patients with critical LAFH, although significant amounts of anchorage loss occur using this appliance. PMID:22457837

  19. Osteochondritis of the Distal Tibial Epiphysis

    PubMed Central

    EL Hajj, Firass; Sebaaly, Amer; Kharrat, Khalil; Ghanem, Ismat

    2012-01-01

    Osteochondritis of the distal tibial epiphysis is a very rare entity. 9 cases have been described in 7 articles and 8 other cases have been mentioned in textbooks. This paper describes the 10th case of osteochondritis of the distal tibial epiphysis and summarizes the clinical and radiological presentations of the 9 other cases. The etiology of this entity is well debated in the literature. We believe that it results from a vascular abnormality in the distal tibial epiphysis associated with a mechanical stress (trauma, excessive overload, etc.). Since it is a self-limited disease, the prognosis is good and the younger the patient is the better the prognosis will be. In general, this entity responds well to conservative treatment. PMID:23193412

  20. Operative treatment of distal radius fractures.

    PubMed

    Vasenius, J

    2008-01-01

    The incidence of distal radius fractures is increasing together with the average age of population. Intra-articular incongruity is the most probable cause of unsatisfactory outcome of distal radius fractures in younger and more active patients. Thus, the main goal in the treatment of distal radius fractures should be restoration of articular congruence. A computed tomography (CT) is recommended to help surgeon in preoperative planning in the treatment of comminuted intra-articular fractures. New implants have been designed to provide stable enough fixation for early mobilisation after surgery and to lower rather high complication rates related to conventional fixation methods such as external fixation and dorsal plating. The most common complications related to volar fixed angle plating such as flexor and extensor tendon problems, median nerve neuropathy, and screw diplacement into the radiocarpal joint are surgeon related and are avoidable with proper education. More randomized prospective studies are needed to prove superiority of any fixation method to another.

  1. Physeal arrest of the distal radius.

    PubMed

    Abzug, Joshua M; Little, Kevin; Kozin, Scott H

    2014-06-01

    Fractures of the distal radius are among the most common pediatric fractures. Although most of these fractures heal without complication, some result in partial or complete physeal arrest. The risk of physeal arrest can be reduced by avoiding known risk factors during fracture management, including multiple attempts at fracture reduction. Athletes may place substantial compressive and shear forces across the distal radial physes, making them prone to growth arrest. Timely recognition of physeal arrest can allow for more predictable procedures to be performed, such as distal ulnar epiphysiodesis. In cases of partial arrest, physeal bar excision with interposition grafting can be performed. Once ulnar abutment is present, more invasive procedures may be required, including ulnar shortening osteotomy or radial lengthening.

  2. Management of hyperkalaemia.

    PubMed

    Maxwell, A P; Linden, K; O'Donnell, S; Hamilton, P K; McVeigh, G E

    2013-01-01

    Hyperkalaemia, an elevated extracellular fluid potassium concentration, is a common electrolyte disorder and is present in 1-10% of hospitalised patients. Elevated serum potassium concentrations are usually asymptomatic but may be associated with electrocardiogram (ECG) changes. Hyperkalaemia occasionally leads to life-threatening cardiac arrhythmias. Prompt recognition of this disorder, patient risk management and administration of appropriate treatment can prevent serious cardiac complications of hyperkalaemia. Further assessment of the underlying basis for hyperkalaemia usually reveals a problem with renal potassium excretion (rather than transcellular shift of potassium or excess potassium intake). Reduced potassium excretion is typically associated with decreased potassium secretion in the aldosterone-sensitive distal nephron of the kidney. Common causes for hyperkalaemia include kidney failure, limited delivery of sodium and water to the distal nephron and drugs that inhibit the renin-angiotensin-aldosterone system. Treatment of life-threatening hyperkalaemia (particularly those patients with ECG changes) involves administration of intravenous calcium salts to stabilise the resting cardiac membrane potential. The potassium concentration can be lowered by administration of intravenous insulin combined with an infusion of glucose to stimulate intracellular uptake of potassium. Nebulised β-2 adrenoceptor agonists can augment the effects of intravenous insulin and glucose pending more definitive management of the recurrent hyperkalaemia risk. Additional management steps include stopping further potassium intake and careful review of prescribed drugs that may be adversely affecting potassium homeostasis. Changes to prescribing systems and an agreed institutional protocol for management of hyperkalaemia can improve patient safety for this frequently encountered electrolyte disorder.

  3. Torsion of wandering spleen and distal pancreas

    SciTech Connect

    Sheflin, J.R.; Lee, C.M.; Kretchmar, K.A.

    1984-01-01

    Wandering spleen is the term applied to the condition in which a long pedicle allows the spleen to lie in an abnormal location. Torsion of a wandering spleen is an unusual cause of an acute abdomen and is rarely diagnosed preoperatively. Associated torsion of the distal pancreas is even more uncommon. The authors describe a patient with torsion of a wandering spleen and distal pancreas, who was correctly diagnosed, and define the merits of the imaging methods used. The initial examination should be /sup 99//sup m/Tc-sulfur colloid liner-spleen scanning.

  4. Contemporary Management of Primary Distal Urethral Cancer.

    PubMed

    Traboulsi, Samer L; Witjes, Johannes Alfred; Kassouf, Wassim

    2016-11-01

    Primary urethral cancer is one of the rare urologic tumors. Distal urethral tumors are usually less advanced at diagnosis compared with proximal tumors and have a good prognosis if treated appropriately. Low-stage distal tumors can be managed successfully with a surgical approach in men or radiation therapy in women. There are no clear-cut indications for the choice of the most appropriate treatment modality. Organ-preserving modalities have shown effective and should be used whenever they do not compromise the oncological safety to decrease the physical and psychological trauma of dismemberment or loss of sexual/urinary function.

  5. Distal Femur Locking Plate: The Answer to All Distal Femoral Fractures

    PubMed Central

    Garg, Sudhir Kumar; Gupta, Parmanand; Jangira, Vivek; Singh, Jagdeep; Rana, Sudhir

    2016-01-01

    Introduction Good results have been published by researchers with distal femur nail, dynamic condylar screw and even addition of a medial plate to a distal femur locking plate for treating distal femur fractures. By this study, we explore the capability of a distal femur locking plate to counter distal femur fractures of extra- articular, partial or intra- articular nature. Positive results have been published by various groups from all over the world. Aim To study the functional and radiological outcome of distal femoral fractures in skeletally mature patients treated by open reduction and internal fixation with distal femur locking plate. Materials and Methods This was a prospective study conducted from January 2012 to March 2014 at the Government Medical College and Hospital (GMCH) with a 2 year follow-up. Twenty five skeletally mature patients with post-traumatic distal femur fractures were included. Patients with open grade 3B and 3C distal femur fractures, according to the Gustilo- Anderson classification and pathological distal femur fractures were excluded from the study. Patients with any fracture other than the distal femur in the ipsilateral limb were excluded from the study. Follow-up at 3 months, 6 months, 1 year and 2 years was carried out and evaluation was done according to the Neer scoring system. The statistical data analysis was carried out using SPSS version 20 (IBM, Chicago, USA). The p-value <0.05 was considered significant. Results Following all principles of fracture reduction, union was achieved in all patients with mean time to radiological union being 19 weeks. The mean Range of Motion (ROM) was 109 degrees with 20 patients having a Neer score graded as excellent to satisfactory. Our study had nine cases which required additional surgeries. Out of these, all nine cases required bone grafting, three also required antibiotic cement bead insertion initially. Three patients developed complications in the form of infection (two cases) and mal

  6. Reconstruction of the Distal Oblique Bundle of the Interosseous Membrane: A Technique to Restore Distal Radioulnar Joint Stability.

    PubMed

    Riggenbach, Michael D; Wright, Thomas W; Dell, Paul C

    2015-11-01

    The distal radioulnar ligament reconstruction is a technique that may be used for distal radioulnar joint instability without arthritis and failed nonsurgical management; clinical results demonstrate resolved or improved stability. Recent literature has focused on the distal oblique bundle of the interosseous membrane and its contributions to stability. This article describes a technically simple surgical technique to reconstruct the distal oblique bundle and restore distal radioulnar joint stability.

  7. Comparative evaluation of molar distalization therapy using pendulum and distal screw appliances

    PubMed Central

    Cafagna, Alessandra; Fontana, Mattia; Cozzani, Mauro

    2015-01-01

    Objective To compare dentoalveolar and skeletal changes produced by the pendulum appliance (PA) and the distal screw appliance (DS) in Class II patients. Methods Forty-three patients (19 men, 24 women) with Class II malocclusion were retrospectively selected for the study. Twenty-four patients (mean age, 12.2 ± 1.5 years) were treated with the PA, and 19 patients (mean age, 11.3 ± 1.9 years) were treated with the DS. The mean distalization time was 7 months for the PA group and 9 months for the DS group. Lateral cephalograms were obtained at T1, before treatment, and at T2, the end of distalization. A Mann-Whitney U test was used for statistical comparisons of the two groups between T1 and T2. Results PA and DS were equally effective in distalizing maxillary molars (4.7 mm and 4.2 mm, respectively) between T1 and T2; however, the maxillary first molars showed less distal tipping in the DS group than in the PA group (3.2° vs. 9.0°, respectively). Moreover, significant premolar anchorage loss (2.7 mm) and incisor proclination (5.0°) were noted in the PA group, whereas premolar distal movement (1.9 mm) and no significant changes at the incisor (0.1°) were observed in the DS group. No significant sagittal or vertical skeletal changes were detected between the two groups during the distalization phase. Conclusions PA and DS seem to be equally effective in distalizing maxillary molars; however, greater distal molar tipping and premolar anchorage loss can be expected using PA. PMID:26258063

  8. Distally based dorsalis pedis island flap for a distal lateral electric burn of the big toe.

    PubMed

    Governa, M; Barisoni, D

    1996-12-01

    Reconstruction of the small defects in the distal portion of the foot has always represented a difficult problem. A case of a young man with a deep electric burn of the distal lateral side of the big toe successfully treated with a distally based dorsalis pedis island flap based on the first dorsal metatarsal artery (FDMA) is presented. The donor site area of the dorsum of the foot was grafted, and deambulation was reassumed 3 weeks later. Advantages; limits and anatomical consideration regarding the viability of the flap are also discussed.

  9. A New Distal Radioulnar Joint Prosthesis

    PubMed Central

    Schuurman, Arnold H.

    2013-01-01

    Pain and instability of the distal radioulnar joint (DRUJ) are common sequelae following a fracture of the distal radius. Many soft tissue procedures have been described, not all of which are successful. Ulnar head replacement prostheses are available but do not always provide stability. We designed a two-part, easy to implant, distal radioulnar prosthesis and implanted it in 19 patients. The first prototype was inserted in 2002 and is still in place. During the study, the design was changed twice, resulting in three groups with four patients in group A, five in group B, and ten in group C. Unfortunately all five prostheses in group B had to be removed because of loosening, while only two prostheses in group C had to be removed, for nonprosthetic reasons. For the 12 patients who retained their prosthesis, forearm function increased while grip strength increased significantly. Pain scores decreased and the Disabilities of the Arm, Shoulder, and Hand (DASH) score improved but remained high. We conclude that the prosthesis offers a new treatment option for ulnar instability following distal ulnar resection. PMID:24436843

  10. Anaesthetic management in thoracoscopic distal tracheal resection.

    PubMed

    Acosta Martínez, J; Beato López, J; Domínguez Blanco, A; López Romero, J L; López Villalobos, J L

    2017-03-01

    Surgical resection of tracheal tumours, especially distal tracheal tumours, is a challenge for the anaesthesiologists involved, mainly due to difficulties in ensuring adequate control of the airway and ventilation. We report the case of a patient undergoing tracheal resection and anastomosis by VATS, emphasizing the anaesthetic management.

  11. Arthroscopic Arthrodesis of the Distal Tibiofibular Syndesmosis.

    PubMed

    Lui, Tun Hing

    2015-01-01

    Chronic syndesmosis disruption can occur if an acute lesion is missed or inadequately managed. This can result in significant functional deficit and development of post-traumatic ankle arthritis. Anatomic reduction of the syndesmosis and maintenance of the reduction by syndesmotic screw fixation alone, ligamentous reconstruction, or fusion of the syndesmosis are recommended. A technique of arthroscopic distal tibiofibular syndesmosis arthrodesis is described.

  12. A mouse model for distal renal tubular acidosis reveals a previously unrecognized role of the V-ATPase a4 subunit in the proximal tubule

    PubMed Central

    Hennings, J Christopher; Picard, Nicolas; Huebner, Antje K; Stauber, Tobias; Maier, Hannes; Brown, Dennis; Jentsch, Thomas J; Vargas-Poussou, Rosa; Eladari, Dominique; Hübner, Christian A

    2012-01-01

    The V-ATPase is a multisubunit complex that transports protons across membranes. Mutations of its B1 or a4 subunit are associated with distal renal tubular acidosis and deafness. In the kidney, the a4 subunit is expressed in intercalated cells of the distal nephron, where the V-ATPase controls acid/base secretion, and in proximal tubule cells, where its role is less clear. Here, we report that a4 KO mice suffer not only from severe acidosis but also from proximal tubule dysfunction with defective endocytic trafficking, proteinuria, phosphaturia and accumulation of lysosomal material and we provide evidence that these findings may be also relevant in patients. In the inner ear, the a4 subunit co-localized with pendrin at the apical side of epithelial cells lining the endolymphatic sac. As a4 KO mice were profoundly deaf and displayed enlarged endolymphatic fluid compartments mirroring the alterations in pendrin KO mice, we propose that pendrin and the proton pump co-operate in endolymph homeostasis. Thus, our mouse model gives new insights into the divergent functions of the V-ATPase and the pathophysiology of a4-related symptoms. PMID:22933323

  13. Functional and oncologic outcomes after nephron-sparing surgery in a solitary kidney: 10 years of experience

    PubMed Central

    Costabel, José Ignacio; Marchiñena, Patricio García; Tirapegui, Federico; Dantur, Augusto; Jurado, Alberto; Gueglio, Guillermo

    2016-01-01

    ABSTRACT Objectives: To evaluate functional and oncologic outcomes of partial nephrectomy (PN) in patients with a solitary kidney. Materials and Methods: A retrospective analysis of patients with a solitary kidney undergoing nephron-sparing surgery between March 2003 and March 2013 was performed. GFR was recorded before the procedure and 3 months after surgery, thus establishing a change (cGFR). Several variables that may influence cGFR were analyzed. Complications are herein described, namely bleeding, fistula, acute renal failure and end-stage renal disease (ESRD). Local recurrence and margin status are also described. Survival rates were calculated using the Kaplan Meier method (2 patients with metastasis at the time of surgery were excluded from the analysis). Results: Forty-five patients were available for analysis. Median follow-up was 27.56 months (r 3-96). Mean cGFR was-7.12mL/min (SD 2.1). Variables significantly related with lower GFR after surgery were loss of renal mass (p=0.01)) and male gender (p=0.03). Four patients (8.8%) experienced hemorrhage. Nine patients (20%) developed a urinary fistula. Only one patient with bleeding required open surgery. Two patients (4.4%) needed transient dialysis. Three patients (6.6%) developed ESRD. Four patients (8.8%) had positive surgical margins (PSMs) and four patients (88%) had local recurrence (2 of these had PSMs). Five patients (11.1%) died during follow-up. Four patients (8.8%) died because of renal cancer. Estimated 2-year overall survival, disease-free survival and cancer specific survival rates were 88.4% (CI 95% 70.5-96); 87.7% (CI 95% 68.1-96) and 92.4% (CI 95% 75-98), respectively. Conclusion: Loss of renal mass and male gender were associated with lower postoperative GFR. Our outcomes were comparable with those in the World literature. PMID:27256179

  14. Long-term Follow-up of Kidney Transplant Recipients in the Spare-the-Nephron-Trial.

    PubMed

    Weir, Matthew R; Pearson, Thomas C; Patel, Anita; Peddi, V Ram; Kalil, Roberto; Scandling, John; Chan, Lawrence; Baliga, Prabhakar; Melton, Larry; Mulgaonkar, Shamkant; Waid, Thomas; Schaefer, Heidi; Youssef, Nasser; Anandagoda, Lali; McCollum, David; Lawson, Sibylle; Gordon, Robert

    2017-01-01

    In the Spare-the-Nephron (STN) Study, kidney transplant recipients randomized about 115 days posttransplant to convert from CNI (calcineurin inhibitor)/MMF to sirolimus (SRL)/MMF had a significantly greater improvement in measured GFR (mGFR) at 12 months compared with those kept on CNI/MMF. The difference at 24 months was not statistically significant. From 14 top enrolling centers, 128 of 175 patients identified with a functioning graft at 2 years consented to enroll in an observational, noninterventional extension study to collect retrospectively and prospectively annual follow-up data for the interval since baseline (completion of the parent STN study at 24 months posttransplant). Overall, 11 patients died, including 5 (7.6%) in the SRL/MMF group and 6 (9.7%) in the CNI/MMF group. Twenty-two grafts have been lost including 10 (15.2%) in the SRL/MMF arm and 12 (19.4%) in the CNI/MMF arm. Death and chronic rejection were the most common causes of graft loss in both arms. There were modestly more cardiovascular events in the MMF/SRL group. Estimated creatinine clearance (Cockcroft-Gault) from baseline out to 6 additional years (8 years posttransplant, ITT analysis, SRL/MMF, n = 34; CNI/MMF, n = 26) was 63.2 ± 28.5 mL/min/1.73 m in the SRL/MMF group and 59.2 ± 27.2 mL/min/1.73 m in the CNI/MMF group and was not statistically significant, but there is a clinically meaningful trend for improved long-term renal function in the SRL/MMF group compared with the CNI/MMF group. The long-term decision for immunosuppression needs to be carefully individualized.

  15. INDICATIONS FOR DISTAL RADIOULNAR ARTHROPLASTY: REPORT ON THREE CLINICAL CASES

    PubMed Central

    Santos, Cláudia; Pereira, Alexandre; Sousa, Marco; Trigeuiros, Miguel; Silva, César

    2015-01-01

    Distal radioulnar arthroplasty is an attractive solution for treating various pathological conditions of the distal radioulnar joint because it allows restoration of stability, load transmission and function. The main indications are: radioulnar impingement after partial or complete resection of the distal ulna; and degenerative, inflammatory or post-traumatic arthritis of the distal radioulnar joint. The authors present three clinical cases of distal radioulnar pathological conditions: two patients with post-traumatic sequelae and one case of distal radioulnar impingement after a Sauvé-Kapandji operation. The three cases were treated surgically with a metallic prosthesis to replace the distal ulna (First Choice - Ascension®). The first two were treated with a resurfacing prosthesis and the last one with a modular prosthesis. All of the patients had achieved pain relief and increased movement of the distal radioulnar joint after one year of postoperative follow-up. PMID:27047827

  16. HEREDITARY DISTAL FORELEG CURVATURE IN THE RABBIT

    PubMed Central

    Pearce, Louise

    1960-01-01

    An inwardly directed curvature of the distal segment of both forelegs of the rabbit has been described. The condition was detected at 2 to 3 weeks of age, developed rapidly, and reached its final and permanent stage at 2 to 3 months of age. Only the distal epiphysis of the ulna was primarily affected and this in the form of a massive chondrodystrophic lesion accompanied by a progressive curvature of the shaft. The curvature of the growing radius was a secondary effect due to the firm, immovable, anatomical connection of the ulna and radius. The positional changes of the wrist and paw were likewise effects secondary to the changed form of the ulna and radius. The bowing abnormality occurred only in certain families of pure bred Beveren, Belgian, French Silver, and Dutch rabbits and was found to be inherited. The mode of inheritance was on the basis of a single recessive unit factor (5). PMID:13733755

  17. Diagnostic and Therapeutic Advances: Distal Symmetric Polyneuropathy

    PubMed Central

    Callaghan, Brian C.; Price, Raymond S.; Feldman, Eva L.

    2016-01-01

    Importance Peripheral neuropathy is a highly prevalent and morbid condition affecting 2–7% of the population. Patients frequently suffer from pain and are at risk of falls, ulcerations, and amputations. We aimed to review recent diagnostic and therapeutic advances in peripheral neuropathy in distal symmetric polyneuropathy, the most common subtype of peripheral neuropathy. Observations and Advances Current evidence supports limited routine laboratory testing in patients with distal symmetric polyneuropathy. Patients without a known cause should have a complete blood count, comprehensive metabolic panel, B12, serum protein electrophoresis with immunofixation, fasting glucose, and a glucose tolerance test. The presence of atypical features such as asymmetry, non-length-dependence, motor predominance, acute or subacute onset, and/or prominent autonomic involvement should prompt a consultation with a neurologist or neuromuscular specialist. Electrodiagnostic tests and magnetic resonance imaging of the neuroaxis are the main drivers of the cost of the diagnostic evaluation, but evidence supporting their use is lacking. Strong evidence supports the use of tricyclic antidepressants, serotonin and norepinephrine reuptake inhibitors, and voltage-gated calcium channel ligands in the treatment of neuropathic pain. More intensive glucose control substantially reduces the incidence of distal symmetric polyneuropathy in patients with type 1 diabetes, but does not in type 2 diabetes. Conclusions and Relevance The opportunity exists to improve guideline concordant testing in distal symmetric polyneuropathy patients. Moreover, the role of electrodiagnostic tests needs to be further defined, and interventions to reduce magnetic resonance imaging use in this population are needed. Even though several efficacious medications exist for neuropathic pain treatment, pain is still under-recognized and undertreated. New disease modifying medications are needed to prevent and treat

  18. [Laparoscopic distal resection of the pancreas].

    PubMed

    Gürlich, R; Sixta, B; Oliverius, M; Kment, M; Rusina, R; Spicák, J; Sváb, J

    2005-09-01

    During the last two years, reports on laparoscopic procedures of the pancreas have been on increase. Laparoscopic resection of the pancreatic cauda is indicated, primarily, for benign cystic lesions of the cauda of the pancreas and for neuroendocrine tumors of the pancreas (mainly insulinomas). We have not recorded any report on the above procedure in the Czech literature. Therefore, in our case review, we have described laparoscopic distal resection of the pancreas with splenectomy for a pseudopapillary tumor of the pancreas.

  19. Distal renal tubular acidosis with hereditary spherocytosis.

    PubMed

    Sinha, Rajiv; Agarwal, Indira; Bawazir, Waleed M; Bruce, Lesley J

    2013-07-01

    Hereditary spherocytosis (HS) and distal renal tubular acidosis (dRTA), although distinct entities, share the same protein i.e. the anion exchanger1 (AE1) protein. Despite this, their coexistence has been rarely reported. We hereby describe the largest family to date with co-existence of dRTA and HS and discuss the molecular basis for the co-inheritance of these conditions.

  20. Distal biceps tendon injuries: diagnosis and management.

    PubMed

    Ramsey, M L

    1999-01-01

    Rupture of the distal biceps tendon occurs most commonly in the dominant extremity of men between 40 and 60 years of age when an unexpected extension force is applied to the flexed arm. Although previously thought to be an uncommon injury, distal biceps tendon ruptures are being reported with increasing frequency. The rupture typically occurs at the tendon insertion into the radial tuberosity in an area of preexisting tendon degeneration. The diagnosis is made on the basis of a history of a painful, tearing sensation in the antecubital region. Physical examination demonstrates a palpable and visible deformity of the distal biceps muscle belly with weakness in flexion and supination. The ability to palpate the tendon in the antecubital fossa may indicate partial tearing of the biceps tendon. Plain radiographs may show hypertrophic bone formation at the radial tuberosity. Magnetic resonance imaging is generally not required to diagnose a complete rupture but may be useful in the case of a partial rupture. Early surgical reattachment to the radial tuberosity is recommended for optimal results. A modified two-incision technique is the most widely used method of repair, but anterior single-incision techniques may be equally effective provided the radial nerve is protected. The patient with a chronic rupture may benefit from surgical reattachment, but proximal retraction and scarring of the muscle belly can make tendon mobilization difficult, and inadequate length of the distal biceps tendon may necessitate tendon augmentation. Postoperative rehabilitation must emphasize protected return of motion for the first 8 weeks after repair. Formal strengthening may begin as early as 8 weeks, with a return to unrestricted activities, including lifting, by 5 months.

  1. Fractures of Distal Radius: An Overview

    PubMed Central

    Meena, Sanjay; Sharma, Pankaj; Sambharia, Abhishek Kumar; Dawar, Ashok

    2014-01-01

    Fractures of distal radius account for up to 20% of all fractures treated in emergency department. Initial assessment includes a history of mechanism of injury, associated injury and appropriate radiological evaluation. Treatment options include conservative management, internal fixation with pins, bridging and non-bridging external fixation, dorsal or volar plating with/without arthroscopy assistance. However, many questions regarding these fractures remain unanswered and good prospective randomized trials are needed. PMID:25657938

  2. Distal Embolic Protection for Renal Arterial Interventions

    SciTech Connect

    Dubel, Gregory J. Murphy, Timothy P.

    2008-01-15

    Distal or embolic protection has intuitive appeal for its potential to prevent embolization of materials generated during interventional procedures. Distal protection devices (DPDs) have been most widely used in the coronary and carotid vascular beds, where they have demonstrated the ability to trap embolic materials and, in some cases, to reduce complications. Given the frequency of chronic kidney disease in patients with renal artery stenosis undergoing stent placement, it is reasonable to propose that these devices may play an important role in limiting distal embolization in the renal vasculature. Careful review of the literature reveals that atheroembolization does occur during renal arterial interventions, although it often goes undetected. Early experience with DPDs in the renal arteries in patients with suitable anatomy suggests retrieval of embolic materials in approximately 71% of cases and renal functional improvement/stabilization in 98% of cases. The combination of platelet inhibition and a DPD may provide even greater benefit. Given the critical importance of renal functional preservation, it follows that everything that can be done to prevent atheroembolism should be undertaken including the use of DPDs when anatomically feasible. The data available at this time support a beneficial role for these devices.

  3. Triplane fracture of the distal radius.

    PubMed

    García-Mata, Serafín; Hidalgo-Ovejero, Angel

    2006-07-01

    A case of triplane fracture of the distal radius is reported in a 13-year-old boy. This exceptional fracture showed displacement, and was healed by closed reduction and 6 weeks of external immobilization. Eighteen months later, the patient showed complete physeal arrest of the distal radius, with radio-ulnar length discrepancy but without any repercussion on wrist mobility. The patient was declared asymptomatic 3 years after the injury. Prompt, physiological physeal arrest reduces the potential of growth deformity. These fractures must be treated conservatively by closed reduction (if displacement exists) and external immobilization, just like a normal one-plane fracture. We may suppose that final radio-ulnar discrepancy could lead to a painful and symptomatic ulno-carpal conflict in adult life. The following characteristics can be associated with this rare fracture: (1) occurrence close to the end of the growth period, as in other types of triplane fractures; (2) evolution towards partial or complete growth arrest of the physis, not requiring treatment and (3) stability of the fracture after closed reduction. In the present case, as in the other reported cases, it may also be added that orthopaedic treatment has been the rule, in contrast with triplane fractures occurring in the distal tibia, in which surgical treatment is indicated.

  4. Novel topical therapies for distal colitis.

    PubMed

    Lawrance, Ian Craig

    2010-10-06

    Distal colitis (DC) can be effectively treated with topical 5ASA agents. Suppositories target the rectum while enemas can reliably reach the splenic flexure. Used in combination with oral 5ASAs, the control of the inflammation is even more effective. Unfortunately, resistant DC does occur and can be extremely challenging to manage. In these patients, the use of steroids, immunosuppressants and the anti-tumor necrosis factor α agents are often required. These, however, can be associated with systemic side effects and are not always effective. The investigation of new topical therapeutic agents is thus required as they are rarely associated with significant blood drug levels and side effects are infrequent. Some of the agents that have been proposed for use in resistant distal colitis include butyrate, cyclosporine and nicotine enemas as well as tacrolimus suppositories and tacrolimus, ecabet sodium, arsenic, lidocaine, rebamipide and Ridogrel(®) enemas. Some of these agents have demonstrated impressive results but the majority of the agents have only been assessed in small open-labelled patient cohorts. Further work is thus required with the investigation of promising agents in the context of randomized double-blinded placebo controlled trials. This review aims to highlight those potentially effective therapies in the management of resistant distal colitis and to promote interest in furthering their investigation.

  5. Distal symmetrical polyneuropathy: definition for clinical research.

    PubMed

    England, J D; Gronseth, G S; Franklin, G; Miller, R G; Asbury, A K; Carter, G T; Cohen, J A; Fisher, M A; Howard, J F; Kinsella, L J; Latov, N; Lewis, R A; Low, P A; Sumner, A J

    2005-01-01

    The objective of this report was to develop a case definition of "distal symmetrical polyneuropathy" to standardize and facilitate clinical research and epidemiological studies. A formalized consensus process was employed to reach agreement after a systematic review and classification of evidence from the literature. The literature indicates that symptoms alone have relatively poor diagnostic accuracy in predicting the presence of polyneuropathy; signs are better predictors of polyneuropathy than symptoms; and single abnormalities on examination are less sensitive than multiple abnormalities in predicting the presence of polyneuropathy. The combination of neuropathic symptoms, signs, and electrodiagnostic findings provides the most accurate diagnosis of distal symmetrical polyneuropathy. A set of case definitions was rank ordered by likelihood of disease. The highest likelihood of polyneuropathy (useful for clinical trials) occurs with a combination of multiple symptoms, multiple signs, and abnormal electrodiagnostic studies. A modest likelihood of polyneuropathy (useful for field or epidemiological studies) occurs with a combination of multiple symptoms and multiple signs when the results of electrodiagnostic studies are not available. A lower likelihood of polyneuropathy occurs when electrodiagnostic studies and signs are discordant. For research purposes, the best approach for defining distal symmetrical polyneuropathy is a set of case definitions rank ordered by estimated likelihood of disease. The inclusion of this formalized case definition in clinical and epidemiological research studies will ensure greater consistency of case selection.

  6. Evaluation of the Hepato and Nephron-Protective Effect of a Polyherbal Mixture using Wistar Albino Rats

    PubMed Central

    Adebesin, Olumide Adedapo; Okpuzor, Joy

    2014-01-01

    Aim: A polyherbal formulation prepared from a mixture of leaves of Gongronema latifolia, Ocimum gratissimum and Vernonia amygdalina (GOV) was evaluated for hepato-nephro protective properties against acetaminophen-induced toxicity in Wistar albino rats. Materials and Methods: Normal Wistar albino rats were orally treated with different doses of GOV extract (2, 4 and 8 g/kg b. wt), distilled water and some standard hepatoprotective drugs such as Liv 52 and silymarin for 14 days. However, a day prior to the 14th day, 3 g/kg body weight dose of Acetaminophen (APAP) was administered p.o. 1h before GOV and the standard drugs to induce hepatic and renal damage. The normal control was setup which received only distilled water. The serum levels of liver marker enzymes, biochemical analytes, antioxidant enzymes and hematological parameters were monitored. Results: The results showed that pretreatment of experimental animals with a different doses of the polyherbal formulation dose dependently caused a significant (p≤0.05) increase in the levels of most of the measured hematological parameters but significantly (p≤0.05) reduced the levels of MCV and monocytes when compared to the APAP induced toxin control group. Rats pretreated with GOV exhibited significant (p < 0.05) increase in serum levels of ALP, ALT, AST, GGT, LDH, Cholesterol, Triglycerides, Urea and a subsequent decrease in Albumin, Creatine and Total protein when compared to the normal rats. This trend in enzyme and biochemical analytes levels were significantly (p < 0.05) reversed when compared to toxin control group. GOV significantly (p < 0.05) and dose dependently increased the serum, kidney and hepatic CAT, GPx, GSH, GST, SOD and total protein activity in APAP induced damage in rats compared to the toxin control groups. Conclusion: The data from this study suggest that the polyherbal formulation possess hepato and nephron-protective potential against acetaminophen induced hepatotoxicity in rats, thus

  7. Distal clavicle osteolysis unrelated to trauma, overuse, or metabolic disease.

    PubMed

    Hawkins, B J; Covey, D C; Thiel, B G

    2000-01-01

    Osteolysis of the distal clavicle has been reported to occur from traumatic, atraumatic (overuse), or systemic causes. Three patients with bilateral osteolysis of the distal clavicles whose osteolysis did not fit these etiologic categories were evaluated. Clinical, imaging, and laboratory evaluations were nonspecific, and histologic sections of the distal clavicle showed evidence of chronic inflammation with reactive change of the articular surface. Patients either had complete resolution or marked improvement of their symptoms after bilateral distal clavicle resection at mean followup of 5 years 3 months. These cases of osteolysis of the distal clavicle represent a category of this disorder not previously described.

  8. Complications of Distal Biceps Tendon Repair

    PubMed Central

    Amin, Nirav H.; Volpi, Alex; Lynch, T. Sean; Patel, Ronak M.; Cerynik, Douglas L.; Schickendantz, Mark S.; Jones, Morgan H.

    2016-01-01

    Background: Anatomic reinsertion of the distal biceps is critical for restoring flexion and supination strength. Single- and double-incision surgical techniques have been reported, analyzing complications and outcomes measures. Which technique results in superior clinical outcomes and the lowest associated complications remains unclear. Hypothesis: We hypothesized that rerupture rates would be similar between the 2 techniques, while nerve complications would be higher for the single-incision technique and heterotopic ossification would be more frequent with the double-incision technique. Study Design: Systematic review and meta-analysis; Level of evidence, 4. Methods: A systematic review was conducted using the PubMed, MEDLINE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), SPORTSDiscus, and the Cochrane Central Register of Controlled Trials databases to identify articles reporting distal biceps ruptures up to August 2013. We included English-language articles on adult patients with a minimum of 3 cases reporting single- and double-incision techniques. Frequencies of each complication as a percentage of total cases were calculated. Fisher exact tests were used to test the association between frequencies for each repair method, with P < .05 considered statistically significant. Odds ratios with 95% CIs were also computed. Results: A total of 87 articles met the inclusion criteria. Lateral antebrachial cutaneous nerve neurapraxia was the most common complication in the single-incision group, occurring in 77 of 785 cases (9.8%). Heterotopic ossification was the most common complication in the double-incision group, occurring in 36 of 498 cases (7.2%). Conclusion: The overall frequency of reported complications is higher for single-incision distal biceps repair than for double-incision repair. The frequencies of rerupture and nerve complications are both higher for single-incision repairs while the frequency of heterotopic ossification is higher for

  9. Hyperammonaemia with distal renal tubular acidosis.

    PubMed

    Miller, S G; Schwartz, G J

    1997-11-01

    The case is reported of an infant with hyperammonaemia secondary to severe distal renal tubular acidosis. A clinical association between increased concentrations of ammonia in serum and renal tubular acidosis has not previously been described. In response to acidosis the infant's kidneys presumably increased ammonia synthesis but did not excrete ammonia, resulting in hyperammonaemia. The patient showed poor feeding, frequent vomiting, and failure to thrive, but did not have an inborn error of metabolism. This case report should alert doctors to consider renal tubular acidosis in the differential diagnosis of severely ill infants with metabolic acidosis and hyperammonaemia.

  10. Total Elbow Arthroplasty for Distal Humerus Fractures.

    PubMed

    Harmer, Luke S; Sanchez-Sotelo, Joaquin

    2015-11-01

    Total elbow arthroplasty is a good treatment alternative for selected patients with distal humerus fractures. Its attractiveness is related to several factors, including the possibility of performing the procedure; leaving the extensor mechanism intact; faster, easier rehabilitation compared with internal fixation; and overall good outcomes reported in terms of both pain relief and function. Implant failure leading to revision surgery does happen, and patients must comply with certain limitations to extend the longevity of their implant. Development of high-performance implants may allow expanding the indications of elbow arthroplasty for fractures.

  11. Creation of distal canine limb lymphedema

    SciTech Connect

    Chen, H.C.; Pribaz, J.J.; O'Brien, B.M.; Knight, K.R.; Morrison, W.A.

    1989-06-01

    A canine model of distal limb lymphedema was established in order to study the treatment of this condition by lymph node transfer. This model was more difficult to establish than whole-limb lymphedema. Significant edema was achieved by a combination of preoperative irradiation and circumferential removal of skin from the irradiated areas followed by removal of the contents of the popliteal fossa. Despite these measures, it was not possible to produce lymphedema in every case, possibly because of the presence of lymphaticovenous shunts and panvascular compensation mechanisms.

  12. [Vascularized iliac crest and distal radius reconstruction].

    PubMed

    Pic Gomis, L; Gomis, R

    2010-12-01

    The authors relate their experience concerning the vascularized iliac crest flap. In the first chapter, they detail the anatomic vascularized osteocutaneous iliac crest. Blood supply arises from the deep and superficial circonflexe iliac artery. Many anastomoses connect the two systems. In the second chapter, they detail the operative technique of free and pedicule hone iliac crest flap. Composite cutaneous bone flaps are also detailed. In the third chapter, they detail informations about treatment of distal radius bone defects with associated skeen flap if necessary.

  13. Distal Renal Tubular Acidosis and Calcium Nephrolithiasis

    NASA Astrophysics Data System (ADS)

    Moe, Orson W.; Fuster, Daniel G.; Xie, Xiao-Song

    2008-09-01

    Calcium stones are commonly encountered in patients with congenital distal renal tubular acidosis, a disease of renal acidification caused by mutations in either the vacuolar H+-ATPase (B1 or a4 subunit), anion exchanger-1, or carbonic anhydrase II. Based on the existing database, we present two hypotheses. First, heterozygotes with mutations in B1 subunit of H+-ATPase are not normal but may harbor biochemical abnormalities such as renal acidification defects, hypercalciuria, and hypocitraturia which can predispose them to kidney stone formation. Second, we propose at least two mechanisms by which mutant B1 subunit can impair H+-ATPase: defective pump assembly and defective pump activity.

  14. Distal oblique osteotomy for tailor's bunion.

    PubMed

    Zvijac, J E; Janecki, C J; Freeling, R M

    1991-12-01

    Thirty-six patients with a total of 50 symptomatic tailor's bunions were evaluated clinically, radiographically, and subjectively, both before and after a distal oblique osteotomy procedure was performed. Thirty-four of 36 patients were satisfied with pain relief. Radiographic measurements derived from this study were consistent with those of other studies. Avascular necrosis, nonunions, or neuroma formation were not encountered in this study. The significant advantages of this procedure are its simplicity, safety, and predictability. The procedure does not require internal fixation or postoperative immobilization.

  15. Acute experimental distal colitis alters colonic transit in rats.

    PubMed

    Myers, B S; Dempsey, D T; Yasar, S; Martin, J S; Parkman, H P; Ryan, J P

    1997-04-01

    Data from humans with active distal colitis suggest that the proximal colon exhibits increased contractile activity and delayed transit, whereas the distal colon shows decreased contractile activity and rapid transit. The present study used the acetic acid rat model of experimental colitis to determine the effect of distal colitis on total and regional colonic transit in vivo and on the in vitro contractility of circular smooth muscle from the proximal and distal colon. Distal colitis was induced in rats by intracolonic administration of 4% acetic acid; sham control rats received saline enemas. Control and colitic rats were studied 2 days postenemas. Total colon transit was determined by calculating the geometric center of distribution of a radiolabeled marker (51Cr) instilled into the proximal colon. Regional transit was assessed by expressing the radioactivity in the cecum, proximal and distal colon, and excreted stool as a percent of total radioactivity. Muscle strips from the proximal and distal colon were stimulated with 100 microM acetylcholine (ACh) and 60 mM KCl and the tension was expressed as kilograms per square centimeter. Distal colitis was characterized by decreased total colon transit, increased retention of marker in the cecum and proximal colon, and decreased retention of marker in the distal colon. In vitro contractility studies revealed that distal colitis increased proximal colon circular smooth muscle contractility and decreased distal colon circular smooth muscle contractility to both ACh and potassium. Distal colitis is associated with regional differences in colonic circular smooth muscle contractility, which may contribute to delayed transit in the proximal colon and rapid transit in the distal colon.

  16. Aqueous outflow: Segmental and distal flow

    PubMed Central

    Swaminathan, Swarup S.; Oh, Dong-Jin; Kang, Min Hyung; Rhee, Douglas J.

    2014-01-01

    A prominent risk factor of primary open-angle glaucoma is ocular hypertension, a pathologic state caused by impaired outflow of aqueous humor through the trabecular meshwork within the iridocorneal angle. The juxtacanalicular region of the trabecular meshwork and the inner wall of Schlemm canal have been identified as the main contributors to aqueous outflow resistance, and both extracellular matrix within the trabecular meshwork and trabecular meshwork cell shape have been shown to affect outflow. Overexpression of multiple ECM proteins in perfused cadaveric human eyes has led to increased outflow resistance and elevated IOP. Pharmacologic agents targeting trabecular meshwork cytoskeletal arrangements have been developed after multiple studies demonstrated the importance of cell shape on outflow. Several groups have shown that aqueous outflow occurs only at certain segments of the trabecular meshwork circumferentially, a concept known as segmental flow. This is based on the theory that aqueous outflow is dependent on the presence of discrete pores within the Schlemm canal. Segmental flow has been described in the eyes of multiple species, including primate, bovine, mouse, and human samples. While the trabecular meshwork appears to be the major source of resistance, trabecular meshwork bypass procedures have been unable to achieve the degree of IOP reduction observed with trabeculectomy, reflecting the potential impact of distal flow, or flow through Schlemm canal and collector channels, on outflow. Multiple studies have demonstrated that outflow occurs preferentially near collector channels, suggesting that these distal structures may be more important to aqueous outflow than previously believed. PMID:25088623

  17. Maxillary molar distalization with first class appliance

    PubMed Central

    Ramesh, Namitha; Palukunnu, Biswas; Ravindran, Nidhi; Nair, Preeti P

    2014-01-01

    Non-extraction treatment has gained popularity for corrections of mild-to-moderate class II malocclusion over the past few decades. The distalization of maxillary molars is of significant value for treatment of cases with minimal arch discrepancy and mild class II molar relation associated with a normal mandibular arch and acceptable profile. This paper describes our experience with a 16-year-old female patient who reported with irregularly placed upper front teeth and unpleasant smile. The patient was diagnosed to have angles class II malocclusion with moderate maxillary anterior crowding, deep bite of 4 mm on a skeletal class II base with an orthognathic maxilla and retrognathic mandible and normal growth pattern. She presented an ideal profile and so molar distalization was planned with the first-class appliance. Molars were distalised by 8 mm on the right and left quadrants and class I molar relation achieved within 4 months. The space gained was utilised effectively to align the arch and establish a class I molar and canine relation. PMID:24577171

  18. Distal radius fracture after proximal row carpectomy

    PubMed Central

    Igeta, Yuka; Naito, Kiyohito; Sugiyama, Yoichi; Obata, Hiroyuki; Aritomi, Kentaro; Kaneko, Kazuo; Obayashi, Osamu

    2015-01-01

    Introduction We encountered a patient with distal radius fracture (DRF) after proximal row carpectomy (PRC). The mechanism of the DRF after PRC is discussed in this report. Presentation of case The patient was a 73-year-old female who had undergone PRC due to Kienböck disease before. The wrist range of motion was: 45° on dorsiflexion and 20° on flexion. DRF has occurred at 3 years after PRC. The fracture type was extra-articular fracture. Osteosynthesis was performed using a volar locking plate. No postoperative complication developed, the Mayo score was excellent at 6 months after surgery, and the daily living activity level recovered to that before injury. Discussion Since the wrist range of motion decreased and the lunate fitted into the joint surface after PRC, making the forearm join with the hand like a single structure, pressure may have been loaded on the weak distal end of the radius from the dorsal side, causing volar displacement and fracture. Conclusion The pressure distribution and range of motion of the radiocarpal joint after PRC are different from those of a normal joint, and the mechanism of fracture also changes due to PRC. PMID:25623755

  19. Role of dopamine in distal retina.

    PubMed

    Popova, E

    2014-05-01

    Dopamine is the most abundant catecholamine in the vertebrate retina. Despite the description of retinal dopaminergic cells three decades ago, many aspects of their function in the retina remain unclear. There is no consensus among the authors about the stimulus conditions for dopamine release (darkness, steady or flickering light) as well as about its action upon the various types of retinal cells. Many contradictory results exist concerning the dopamine effect on the gross electrical activity of the retina [reflected in electroretinogram (ERG)] and the receptors involved in its action. This review summarized current knowledge about the types of the dopaminergic neurons and receptors in the retina as well as the effects of dopamine receptor agonists and antagonists on the light responses of photoreceptors, horizontal and bipolar cells in both nonmammalian and mammalian retina. Special focus of interest concerns their effects upon the diffuse ERG as a useful tool for assessment of the overall function of the distal retina. An attempt is made to reveal some differences between the dopamine actions upon the activity of the ON versus OFF channel in the distal retina. The author has included her own results demonstrating such differences.

  20. Atypical Miyoshi distal myopathy: A case report

    PubMed Central

    Wang, Meiling; Guo, Yujie; Fu, Yong; Jia, Rui; Chen, Gang

    2016-01-01

    Five distinct predominant distal myopathies have been identified with discrete clinical and genetic patterns. Miyoshi myopathy (MM; early adult-onset, type 2) is a subtype of dysferlinopathy. Furthermore, MM is the most common form of autosomal recessive distal myopathy. MM is typically characterized by muscular weakness, initially affecting the gastrocnemius or soleus muscle from the late teens or early adulthood. The present study reports a case of MM that was confirmed by pathological and immunohistochemical methods, in addition to a review of the relevant literature. A 37-year-old male patient presented with muscular weakness in the left foot. This clinical manifestation was not typical of MM, and the patient was initially diagnosed with inflammatory myopathy. He was treated with dexamethasone at a dose of 10 mg for 5 days followed by gradual tapering, following which the symptoms were alleviated; however, the pathology, immunohistochemistry and electromyography eventually confirmed the diagnosis of MM. The treatment was then terminated and the patient was discharged. The present study further supports the underlying heterogeneity in atypical MM-like phenotypes. Dysferlin protein deficiency can be identified by pathological examination. The pathology of dysferlinopathy is characterized by changes of muscular dystrophy. Inflammatory cellular infiltration is a relatively common finding in the muscle biopsies from numerous patients with dysferlinopathy. Therefore, the detection of dysferlin deficiency or marked reduction on the sarcolemma using immunohistochemical staining is important for the diagnosis of dysferlinopathy. PMID:27882118

  1. Biotin absorption by distal rat intestine

    SciTech Connect

    Bowman, B.B.; Rosenberg, I.H.

    1987-12-01

    We used the in vivo intestinal loop approach, with short (10-min) and long (3-h) incubations, to examine biotin absorption in proximal jejunum, distal ileum, cecum and proximal colon. In short-term studies, luminal biotin disappearance from rat ileum was about half that observed in the jejunum, whereas absorption by proximal colon was about 12% of that in the jejunum. In 3-h closed-loop studies, the absorption of 1.0 microM biotin varied regionally. Biotin absorption was nearly complete in the small intestine after 3 h; however, only about 15% of the dose had been absorbed in the cecum and 27% in the proximal colon after 3 h. Independent of site of administration, the major fraction of absorbed biotin was recovered in the liver; measurable amounts of radioactive biotin were also present in kidney and plasma. The results support the potential nutritional significance for the rat of biotin synthesized by bacteria in the distal intestine, by demonstrating directly an absorptive capability of mammalian large bowel for this vitamin.

  2. Ruptures of the distal biceps tendon.

    PubMed

    Ward, James P; Shreve, Mark C; Youm, Thomas; Strauss, Eric J

    2014-01-01

    Distal biceps ruptures occur most commonly in middle-aged males and result from eccentric contraction of the biceps tendon. The injury typically presents with pain and a tearing sensation in the antecubital fossa with resultant weakness in flexion and supination strength. Physical exam maneuvers and diagnostic imaging aid in determining the diagnosis. Nonoperative management is reserved for elderly, low demand patients, while operative intervention is generally pursued for younger patients and can consist of nonanatomic repair to the brachialis or anatomic repair to the radial tuberosity. Anatomic repair through a one-incision or two-incision approach is commonplace, while the nonanatomic repairs are rarely performed. No clear advantage exists in operative management with a one-incision versus two-incision techniques. Chronic ruptures present a more difficult situation, and allograft augmentation is often necessary. Common complications after repair include transient nerve palsy, which often resolves, and heterotopic ossification. Despite these possible complications, most studies suggest that better patient outcomes are obtained with operative, anatomic reattachment of the distal biceps tendon.

  3. Distal metatarsal coalition: A rare case report

    PubMed Central

    Vun, Shen Hwa; Drampalos, Efstathios; Shareef, Sajan; Sinha, Satyajit; Bramley, Diane

    2015-01-01

    Introduction Metatarsal coalition is an extremely rare condition. We report the second documented case of 4th and 5th distal metatarsal coalition in the literature. Presentation of case An eight-year-old girl was referred to an orthopaedic clinic with a four-month history of forefoot pain and swelling on the plantar aspect of the right little toe. Radiograph and clinical examination confirmed distal metatarsal coalition between the 4th and 5th metatarsals. Following a period of conservative treatment, excision was eventually performed due to worsening symptoms. Patient re-attended two years later with a recurrence of the coalition confirmed by computed tomography (CT) scan. The case was discussed at a tertiary paediatric orthopaedic insititution. Decision was made to manage patient conservatively with insole and physiotherapy until skeletal maturity. A year later, patient’s symptoms did not worsen, and her foot displayed no evidence of change in the arch and shape. Discussion The timing of ossification of coalition varies from one anatomical site to another. Surgery when performed before ossification is complete runs the risk of recurrence. Conclusion Our case report illustrates the importance of restoring normal weight bearing dynamics and pain relief when managing metatarsal coalition, or synostosis in skeletally immature patients. We recommend persevering with conservative treatment, with operative treatment reserved only as a later option, and ideally, until skeletal maturity is achieved. PMID:25670408

  4. Growth disturbances after distal tibial physeal fractures.

    PubMed

    Berson, L; Davidson, R S; Dormans, J P; Drummond, D S; Gregg, J R

    2000-01-01

    Twenty-four patients with distal tibial growth disturbance were reviewed. Disturbances were classified as physeal bar (prior to deformity), angular, linear or combined deformities. Treatment consisted of osteotomy in fourteen, epiphyseodesis in seven, excision of bony bar in two, and observation in one patient. Follow up was an average 36.6 months (range 4-129 months) after treatment of growth disturbance. The age at time of injury was 10.4 years of age average (range 3-15 years). There were 12 SH2, 2 SH3, 7 SH4, and 3 SH5 distal tibial physeal fractures. Thirteen of 15 fractures considered high energy and only 1 of 9 fractures considered low energy resulted in angular deformity. Angular and linear deformities presented an average 46 months (range 12-120 months) and physeal bars at an average 14 months (range 6-25 months) after injury. Patients with a delay in presentation of growth disturbance greater than 24 months had angular deformities in 92% compared with 33% in children presenting less than or at 24 months. Treatment based on type of deformity, age at time of injury, and growth remaining was considered successful in 83%. Patients with angular or linear deformities were more likely to present late, have high energy injuries, be male patients and have Salter-Harris types IV and V. Early diagnosis and treatment of growth disturbance can prevent severe deformity.

  5. Biomechanical Comparison of Osteoporotic Distal Radius Fractures Fixed by Distal Locking Screws with Different Length

    PubMed Central

    Liu, Xiong; Wu, Wei-dong; Fang, Ya-feng; Zhang, Mei-chao; Huang, Wen-hua

    2014-01-01

    Objectives To evaluate the postoperative stability of osteoporotic distal radius fractures fixed with distal locking screws with different length. Methods A comminuted extra-articular dorsally unstable distal radius fracture, treated with volar locking plate system, was created. The 18 specimens were randomized into 3 groups based on distal locked screws with different length: Group A had unicortical screws with 50% length to the dorsal cortex. Group B had unicortical screws with 75% length to the dorsal cortex. Group C had bicortical screws. Axial compression and bending loads were imposed on the models before and after cycling testing as well as load to clinical and catastrophic failure. Results Minimum change in stiffness was observed before and after fatigue for all groups. The final stiffness to bending forces was statistically similar in all groups, but stiffness to axial compression was statistically significant different: Group A approached significance with respect to groups B and C (P = 0.017, 0.009), whereas stiffness in group B and C was statistically similar (P = 0.93). Load to clinical failure was significantly less for group A (456.54±78.59 N) compared with groups B (580.24±73.85 N) and C (591.07±38.40 N). Load to catastrophic failure was statistically similar between groups, but mean values for Group A were 18% less than means for Group C. Conclusions The volar locking plate system fixed with unicortical locking screws with at least 75% length not only produced early stability for osteoporotic distal radius fractures, but also avoided extensor tendon complications due to dorsal screw protrusion. PMID:25080094

  6. Distal Communication by Chimpanzees (Pan troglodytes): Evidence for Common Ground?

    PubMed Central

    Leavens, David A.; Reamer, Lisa A.; Mareno, Mary Catherine; Russell, Jamie L.; Wilson, Daniel; Schapiro, Steven J.; Hopkins, William D.

    2015-01-01

    van der Goot et al. (2014) proposed that distal, deictic communication indexed the appreciation of the psychological state of a common ground between a signaler and a receiver. In their study, great apes did not signal distally, which they construed as evidence for the human uniqueness of a sense of common ground. This study exposed 166 chimpanzees to food and an experimenter, at an angular displacement, to ask, “Do chimpanzees display distal communication?” Apes were categorized as (a) proximal or (b) distal signalers on each of four trials. The number of chimpanzees who communicated proximally did not statistically differ from the number who signaled distally. Therefore, contrary to the claim by van der Goot et al., apes do communicate distally. PMID:26292996

  7. Robotic-assisted transperitoneal nephron-sparing surgery for small renal masses with associated surgical procedures: surgical technique and preliminary experience.

    PubMed

    Ceccarelli, Graziano; Codacci-Pisanelli, Massimo; Patriti, Alberto; Ceribelli, Cecilia; Biancafarina, Alessia; Casciola, Luciano

    2013-09-01

    Small renal masses (T1a) are commonly diagnosed incidentally and can be treated with nephron-sparing surgery, preserving renal function and obtaining the same oncological results as radical surgery. Bigger lesions (T1b) may be treated in particular situations with a conservative approach too. We present our surgical technique based on robotic assistance for nephron-sparing surgery. We retrospectively analysed our series of 32 consecutive patients (two with 2 tumours and one with 4 bilateral tumours), for a total of 37 robotic nephron-sparing surgery (RNSS) performed between June 2008 and July 2012 by a single surgeon (G.C.). The technique differs depending on tumour site and size. The mean tumour size was 3.6 cm; according to the R.E.N.A.L. Nephrometry Score 9 procedures were considered of low, 14 of moderate and 9 of hight complexity with no conversion in open surgery. Vascular clamping was performed in 22 cases with a mean warm ischemia time of 21.5 min and the mean total procedure time was 149.2 min. Mean estimated blood loss was 187.1 ml. Mean hospital stay was 4.4 days. Histopathological evaluation confirmed 19 cases of clear cell carcinoma (all the multiple tumours were of this nature), 3 chromophobe tumours, 1 collecting duct carcinoma, 5 oncocytomas, 1 leiomyoma, 1 cavernous haemangioma and 2 benign cysts. Associated surgical procedures were performed in 10 cases (4 cholecystectomies, 3 important lyses of peritoneal adhesions, 1 adnexectomy, 1 right hemicolectomy, 1 hepatic resection). The mean follow-up time was 28.1 months ± 12.3 (range 6-54). Intraoperative complications were 3 cases of important bleeding not requiring conversion to open or transfusions. Regarding post-operative complications, there were a bowel occlusion, 1 pleural effusion, 2 pararenal hematoma, 3 asymptomatic DVT (deep vein thrombosis) and 1 transient increase in creatinine level. There was no evidence of tumour recurrence in the follow-up. RNSS is a safe and feasible technique

  8. New concepts in the treatment of distal radius fractures.

    PubMed

    Taras, John S; Ladd, Amy L; Kalainov, David M; Ruch, David S; Ring, David C

    2010-01-01

    Fracture of the distal radius is the type of fracture most commonly seen in emergency departments. The understanding of nonsurgical and surgical care of distal radius fractures is evolving with recently developed methods of fixation. It is worthwhile to review some new methods of treatment, the role of bone grafting and synthetic substitutes, the principles of complex fracture management, and the treatment of common complications of distal radius fractures.

  9. Pitfalls in the application of distal femur plates for fractures.

    PubMed

    Collinge, Cory A; Gardner, Michael J; Crist, Brett D

    2011-11-01

    Despite design features intended to aid the surgeon in restoring proper alignment, malunion and implant-related problems are relatively common after a distal femur fracture treated with plate fixation. This article presents case examples of these problems followed by a discussion of the relevant distal femoral anatomy, design features of modern locked distal femur plating systems, and technical points necessary to avoid malunion and implant-related problems when using these devices.

  10. Ultrasound-Assisted Distal Radius Fracture Reduction

    PubMed Central

    Socransky, Steve; Skinner, Andrew; Bromley, Mark; Smith, Andrew; Anawati, Alexandre; Middaugh, Jeff; Ross, Peter

    2016-01-01

    Introduction Closed reduction of distal radius fractures (CRDRF) is a commonly performed emergency department (ED) procedure. The use of point-of-care ultrasound (PoCUS) to diagnose fractures and guide reduction has previously been described. The primary objective of this study was to determine if the addition of PoCUS to CRDRF changed the perception of successful initial reduction. This was measured by the rate of further reduction attempts based on PoCUS following the initial clinical determination of achievement of best possible reduction. Methods  We performed a multicenter prospective cohort study, using a convenience sample of adult ED patients presenting with a distal radius fracture to five Canadian EDs. All study physicians underwent standardized PoCUS training for fractures. Standard clinically-guided best possible fracture reduction was initially performed. PoCUS was then used to assess the reduction adequacy. Repeat reduction was performed if deemed indicated. A post-reduction radiograph was then performed. Clinician impression of reduction adequacy was scored on a 5 point Likert scale following the initial clinically-guided reduction and following each PoCUS scan and the post-reduction radiograph. Results  There were 131 patients with 132 distal radius fractures. Twelve cases were excluded prior to analysis. There was no significant difference in the assessment of the initial reduction status by PoCUS as compared to the clinical exam (mean score: 3.8 vs. 3.9; p = 0.370; OR 0.89; 95% CI 0.46 to 1.72; p = 0.87). Significantly fewer cases fell into the uncertain category with PoCUS than with clinical assessment (2 vs 12; p = 0.008). Repeat reduction was performed in 49 patients (41.2%). Repeat reduction led to a significant improvement (p < 0.001) in the PoCUS determined adequacy of reduction (mean score: 4.3 vs 3.1; p < 0.001). In this group, the odds ratio for adequate vs. uncertain or inadequate reduction assessment using PoCUS was 12.5 (95% CI 3

  11. SPAK isoforms and OSR1 regulate sodium-chloride co-transporters in a nephron-specific manner.

    PubMed

    Grimm, P Richard; Taneja, Tarvinder K; Liu, Jie; Coleman, Richard; Chen, Yang-Yi; Delpire, Eric; Wade, James B; Welling, Paul A

    2012-11-02

    STE20/SPS-1-related proline-alanine-rich protein kinase (SPAK) and oxidative stress-related kinase (OSR1) activate the potassium-dependent sodium-chloride co-transporter, NKCC2, and thiazide-sensitive sodium-chloride cotransporter, NCC, in vitro, and both co-localize with a kinase regulatory molecule, Cab39/MO25α, at the apical membrane of the thick ascending limb (TAL) and distal convoluted tubule (DCT). Yet genetic ablation of SPAK in mice causes a selective loss of NCC function, whereas NKCC2 becomes hyperphosphorylated. Here, we explore the underlying mechanisms in wild-type and SPAK-null mice. Unlike in the DCT, OSR1 remains at the TAL apical membrane of KO mice where it is accompanied by an increase in the active, phosphorylated form of AMP-activated kinase. We found an alterative SPAK isoform (putative SPAK2 form), which modestly inhibits co-transporter activity in vitro, is more abundant in the medulla than the cortex. Thus, enhanced NKCC2 phosphorylation in the SPAK knock-out may be explained by removal of inhibitory SPAK2, sustained activity of OSR1, and activation of other kinases. By contrast, the OSR1/SPAK/M025α signaling apparatus is disrupted in the DCT. OSR1 becomes largely inactive and displaced from M025α and NCC at the apical membrane, and redistributes to dense punctate structures, containing WNK1, within the cytoplasm. These changes are paralleled by a decrease in NCC phosphorylation and a decrease in the mass of the distal convoluted tubule, exclusive to DCT1. As a result of the dependent nature of OSR1 on SPAK in the DCT, NCC is unable to be activated. Consequently, SPAK(-/-) mice are highly sensitive to dietary salt restriction, displaying prolonged negative sodium balance and hypotension.

  12. [Post-transplant distal limb syndrome].

    PubMed

    Borghi Torzillo, María Florencia; Bavcar, Paula; Lutfi, Rubén; Díaz, Alberto C

    2017-01-01

    The post-transplant distal limb syndrome is a not well known entity, with a prevalence of 5% in patients with renal transplant. Its diagnosis is based on clinical symptoms, bone scintigraphy and MRI, it has a benign course and the patient recovers without sequel. We present the case of a 37-year-old male, with medical history of hypertension, Berger's disease in 1999 that required dialysis three times a week for four years (2009-2013) and renal transplant in 2013. The patient consults on January 2014 referring severe pain in both feet, with sudden onset; he remembers the exact date of the beginning of the pain and denies trauma, pain prevents ambulation. The bone scintigraphy shows pathological uptake in both feet with no difference between the two. Although there is no treatment for this disease, it has a benign course.

  13. Severe Salt-Losing Syndrome and Hyperkalemia Induced by Adult Nephron-Specific Knockout of the Epithelial Sodium Channel α-Subunit.

    PubMed

    Perrier, Romain; Boscardin, Emilie; Malsure, Sumedha; Sergi, Chloé; Maillard, Marc P; Loffing, Johannes; Loffing-Cueni, Dominique; Sørensen, Mads Vaarby; Koesters, Robert; Rossier, Bernard C; Frateschi, Simona; Hummler, Edith

    2016-08-01

    Systemic pseudohypoaldosteronism type 1 (PHA-1) is a severe salt-losing syndrome caused by loss-of-function mutations of the amiloride-sensitive epithelial sodium channel (ENaC) and characterized by neonatal life-threatening hypovolemia and hyperkalemia. The very high plasma aldosterone levels detected under hypovolemic or hyperkalemic challenge can lead to increased or decreased sodium reabsorption, respectively, through the Na(+)/Cl(-) cotransporter (NCC). However, the role of ENaC deficiency remains incompletely defined, because constitutive inactivation of individual ENaC subunits is neonatally lethal in mice. We generated adult inducible nephron-specific αENaC-knockout mice (Scnn1a(Pax8/LC1)) that exhibit hyperkalemia and body weight loss when kept on a regular-salt diet, thus mimicking PHA-1. Compared with control mice fed a regular-salt diet, knockout mice fed a regular-salt diet exhibited downregulated expression and phosphorylation of NCC protein, despite high plasma aldosterone levels. In knockout mice fed a high-sodium and reduced-potassium diet (rescue diet), although plasma aldosterone levels remained significantly increased, NCC expression returned to control levels, and body weight, plasma and urinary electrolyte concentrations, and excretion normalized. Finally, shift to a regular diet after the rescue diet reinstated the symptoms of severe PHA-1 syndrome and significantly reduced NCC phosphorylation. In conclusion, lack of ENaC-mediated sodium transport along the nephron cannot be compensated for by other sodium channels and/or transporters, only by a high-sodium and reduced-potassium diet. We further conclude that hyperkalemia becomes the determining factor in regulating NCC activity, regardless of sodium loss, in the ENaC-mediated salt-losing PHA-1 phenotype.

  14. Three-dimensional in vivo kinematics of the distal radioulnar joint in malunited distal radius fractures.

    PubMed

    Moore, Douglas C; Hogan, Kathleen A; Crisco, Joseph J; Akelman, Edward; Dasilva, Manuel F; Weiss, Arnold-Peter C

    2002-03-01

    How malunion of the distal radius affects the kinematics of the distal radioulnar joint in vivo was evaluated. A novel computed tomography image-based technique was used to quantify radioulnar motion in both wrists of 9 patients who had unilateral malunited distal radius fractures. In the injured wrists dorsal angulation averaged 21 degrees +/- 6 degrees, radial inclination averaged 18 degrees +/- 5 degrees, and radial shortening averaged 21 +/- 3 mm. Clinically, the average range of motion of the injured wrists was 75 degrees +/- 25 degrees pronation and 73 degrees +/- 23 degrees supination. Kinematics of the radius during pronation and supination in the malunited forearms was indistinguishable from that in the uninjured forearms. In both the axis of rotation of the radius passed through the center of the ulnar head, although it shifted slightly ulnar and volar in supination and radial and dorsal during pronation. In contrast to previous in vitro biomechanical findings, there was no dorsovolar radial translation at the extremes of pronation or supination and no translation of the radius along the rotation axis. Soft tissues may play a larger role in limiting function than previously appreciated, and treatment may require correction of altered soft tissue structures as well as any abnormal bone anatomy.

  15. Incidence of distal femoral and distal tibial deformities in infantile and adolescent blount disease.

    PubMed

    Myers, Thomas G; Fishman, Michael K; McCarthy, James J; Davidson, Richard S; Gaughan, John

    2005-01-01

    The purpose of this study was to assess distal femoral and tibial deformity in patients with infantile and adolescent Blount disease. This was a retrospective review of patients at the authors' institution diagnosed with Blount disease. Thirty-eight patients (21 in the infantile group and 17 in the adolescent group) met the study criteria. Measurements of the anatomic lateral distal femoral angle (aLDFA), anatomic lateral distal tibial angle (aLDTA), and tibiofemoral angle (TFA) were made from long-leg radiographs. The results of the infantile and adolescent measurements were compared with each other and to a normal database. Intraobserver and interobserver error was determined. The adolescent aLDFA measurements were significantly greater (more varus) than for the infantile group and normal database. The aLDTA (ankle) measurements were not statistically different between the two groups, or from the normal database. Analysis of both intraobserver and interobserver error for the aLDFA and aLDTA showed good reliability.

  16. An intrinsic timer specifies distal structures of the vertebrate limb.

    PubMed

    Saiz-Lopez, Patricia; Chinnaiya, Kavitha; Campa, Victor M; Delgado, Irene; Ros, Maria A; Towers, Matthew

    2015-09-18

    How the positional values along the proximo-distal axis (stylopod-zeugopod-autopod) of the limb are specified is intensely debated. Early work suggested that cells intrinsically change their proximo-distal positional values by measuring time. Recently, however, it is suggested that instructive extrinsic signals from the trunk and apical ectodermal ridge specify the stylopod and zeugopod/autopod, respectively. Here, we show that the zeugopod and autopod are specified by an intrinsic timing mechanism. By grafting green fluorescent protein-expressing cells from early to late chick wing buds, we demonstrate that distal mesenchyme cells intrinsically time Hoxa13 expression, cell cycle parameters and the duration of the overlying apical ectodermal ridge. In addition, we reveal that cell affinities intrinsically change in the distal mesenchyme, which we suggest results in a gradient of positional values along the proximo-distal axis. We propose a complete model in which a switch from extrinsic signalling to intrinsic timing patterns the vertebrate limb.

  17. Surgical management of pancreatic cancer--distal pancreatectomy.

    PubMed

    Parikh, Purvi Y; Lillemoe, Keith D

    2015-02-01

    Distal pancreatectomy is the standard procedure for tumors located in the body and tail of the pancreas. In the last three decades, significant progress has been made with regard to technical aspects as well as perioperative care so that excellent mortality and morbidity rates can be achieved. Recently, there is growing evidence that distal pancreatectomy may be performed laparoscopically in selected patients, offering the advantages of minimally invasive surgery. Unfortunately, the oncologic outcomes for pancreatic adenocarcinoma remain poor, in part due to the late stage of presentation in most patients. We review the history of distal pancreatectomy, discuss current indications for performing this procedure, compare operative techniques in performing distal pancreatectomy, and review both the early complications seen in patients who have undergone a distal pancreatectomy and the long-term metabolic and oncologic outcomes of these patients.

  18. Localization of a Gene for Autosomal Recessive Distal Renal Tubular Acidosis with Normal Hearing (rdRTA2) to 7q33-34

    PubMed Central

    Karet, Fiona E.; Finberg, Karin E.; Nayir, Ahmet; Bakkaloglu, Aysin; Ozen, Seza; Hulton, Sally A.; Sanjad, Sami A.; Al-Sabban, Essam A.; Medina, Juan F.; Lifton, Richard P.

    1999-01-01

    Summary Failure of distal nephrons to excrete excess acid results in the “distal renal tubular acidoses” (dRTA). Early childhood features of autosomal recessive dRTA include severe metabolic acidosis with inappropriately alkaline urine, poor growth, rickets, and renal calcification. Progressive bilateral sensorineural hearing loss (SNHL) is evident in approximately one-third of patients. We have recently identified mutations in ATP6B1, encoding the B-subunit of the collecting-duct apical proton pump, as a cause of recessive dRTA with SNHL. We now report the results of genetic analysis of 13 kindreds with recessive dRTA and normal hearing. Analysis of linkage and molecular examination of ATP6B1 indicated that mutation in ATP6B1 rarely, if ever, accounts for this phenotype, prompting a genomewide linkage search for loci underlying this trait. The results strongly supported linkage with locus heterogeneity to a segment of 7q33-34, yielding a maximum multipoint LOD score of 8.84 with 68% of kindreds linked. The LOD-3 support interval defines a 14-cM region flanked by D7S500 and D7S688. That 4 of these 13 kindreds do not support linkage to rdRTA2 and ATP6B1 implies the existence of at least one additional dRTA locus. These findings establish that genes causing recessive dRTA with normal and impaired hearing are different, and they identify, at 7q33-34, a new locus, rdRTA2, for recessive dRTA with normal hearing. PMID:10577919

  19. P2Y2 receptor activation inhibits the expression of the sodium-chloride cotransporter NCC in distal convoluted tubule cells.

    PubMed

    Gailly, P; Szutkowska, M; Olinger, E; Debaix, H; Seghers, F; Janas, S; Vallon, V; Devuyst, O

    2014-11-01

    Luminal nucleotide stimulation is known to reduce Na(+) transport in the distal nephron. Previous studies suggest that this mechanism may involve the thiazide-sensitive Na(+)-Cl(-) cotransporter (NCC), which plays an essential role in NaCl reabsorption in the cells lining the distal convoluted tubule (DCT). Here we show that stimulation of mouse DCT (mDCT) cells with ATP or UTP promoted Ca(2+) transients and decreased the expression of NCC at both mRNA and protein levels. Specific siRNA-mediated silencing of P2Y2 receptors almost completely abolished ATP/UTP-induced Ca(2+) transients and significantly reduced ATP/UTP-induced decrease of NCC expression. To test whether local variations in the intracellular Ca(2+) concentration ([Ca(2+)]i) may control NCC transcription, we overexpressed the Ca(2+)-binding protein parvalbumin selectively in the cytosol or in the nucleus of mDCT cells. The decrease in NCC mRNA upon nucleotide stimulation was abolished in cells overexpressing cytosolic PV but not in cells overexpressing either a nuclear-targeted PV or a mutated PV unable to bind Ca(2+). Using a firefly luciferase reporter gene strategy, we observed that the activity of NCC promoter region from -1 to -2,200 bp was not regulated by changes in [Ca(2+)]i. In contrast, high cytosolic calcium level induced instability of NCC mRNA. We conclude that in mDCT cells: (1) P2Y2 receptor is essential for the intracellular Ca(2+) signaling induced by ATP/UTP stimulation; (2) P2Y2-mediated increase of cytoplasmic Ca(2+) concentration down-regulates the expression of NCC; (3) the decrease of NCC expression occurs, at least in part, via destabilization of its mRNA.

  20. Distal Expression of knotted1 in Maize Leaves Leads to Reestablishment of Proximal/Distal Patterning and Leaf Dissection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maize (Zea mays) leaves provide a useful system to study how proximal/distal patterning is established because of the distinct tissues found in the distal blade and the proximal sheath. Several mutants disrupt this pattern, including the dominant knotted1-like homeobox (knox) mutants. knox genes enc...

  1. Review article: problematic proctitis and distal colitis.

    PubMed

    Gionchetti, P; Rizzello, F; Morselli, C; Campieri, M

    2004-10-01

    About two-thirds of patients with ulcerative colitis have an inflammatory involvement distal to the splenic flexure, and therefore may be effectively treated with topical treatment, allowing the delivery of the active drug directly to the site of inflammation and limiting systemic absorption and potential side-effects. Topical aminosalicylate therapy is the most effective approach, and most patients will benefit hugely, provided that the formulation reaches the upper extent of the disease. Therefore, the choice of topical preparation should be based on the proximal extent of the disease and on patient preference. Oral aminosalicylates are less effective than topical therapies; however, a combination of oral and topical aminosalicylates can be successful in refractory patients. Alternatives to aminosalicylates are the new glucocorticoids, budesonide and beclometasone dipropionate, either as enemas or oral formulations (only beclometasone dipropionate). A combination of oral or rectal new glucocorticoids with rectal aminosalicylates should be considered in patients refractory to either approach. When these measures fail, treatment with oral glucocorticoids is necessary. An intensive intravenous steroid regimen is also helpful for patients refractory to oral steroids. Alternative treatments include short-chain fatty acid enemas, nicotine enemas and patches, acetarsol suppositories, ciclosporin enemas and epidermal growth factor enemas. Several factors potentially having a negative impact on therapeutic response include concurrent enteric pathogens, coexistent irritable bowel syndrome, patient nonadherence to therapy, inadequate dosing and duration of therapy, and proximal progression of the disease. Surgical colectomy may be required in those rare patients refractory or intolerant to pharmacotherapy.

  2. Distal interstitial epididymitis in young rats.

    PubMed

    Hoffmann, Guenther; Belote, Duane A; Suttie, Andrew W; Buetow, Bernard S; Muhumuza, Luke

    2015-04-01

    A sporadic, diffuse, interstitial mixed cell epididymitis of unknown etiology was noted in the epididymal cauda and distal corpus of young control Sprague-Dawley (SD) rats. Rats from 2 different suppliers were examined as part of routine toxicology studies. The incidence of this finding was 5/5 (study 1), 2/7 (study 2), and 2/7 (study 3). Although 2 of these studies partially overlapped temporally, none of the affected animals from any study was maintained concurrently with affected animals from any of the other 2 studies, and infectious causes, control article toxicity, or autoimmune processes were considered unlikely etiologies. Inflammation similar to that noted in the epididymides of these young rats was not present in other tissues and was not noted in study cohorts sacrificed at ages older than approximately 11 weeks or in rats of similar age from other concurrent studies. Similar findings were noted sporadically in historical control data, and consequently an age-related finding of unknown etiology and occurring in sporadic clusters is reported in SD rats ≤11 weeks old.

  3. Resection Interposition Arthroplasty for Failed Distal Ulna Resections

    PubMed Central

    Papatheodorou, Loukia K.; Rubright, James H.; Kokkalis, Zinon T.; Sotereanos, Dean G.

    2013-01-01

    The major complications of distal ulna resection, the Darrach procedure, are radioulnar impingement and instability. High failure rates have been reported despite published modifications of the Darrach procedure. Several surgical techniques have been developed to treat this difficult problem and to mitigate the symptoms associated with painful convergence and impingement. No technique has demonstrated clinical superiority. Recently, implant arthroplasty of the distal ulna has been endorsed as an option for the management of the symptomatic patient with a failed distal ulna resection. However, there are concerns for implant longevity, especially in young, active adults. Resection interposition arthroplasty relies on interposition of an Achilles tendon allograft between the distal radius and the resected distal ulna. Although this technique does not restore normal mechanics of the distal radioulnar joint, it can prevent painful convergence of the radius on the ulna. Achilles allograft interposition arthroplasty is a safe and highly effective alternative for failed distal ulna resections, especially for young, active patients, in whom an implant or alternative procedure may not be appropriate. PMID:24436784

  4. Proximal and distal muscle fatigue differentially affect movement coordination

    PubMed Central

    Cowley, Jeffrey C.

    2017-01-01

    Muscle fatigue can cause people to change their movement patterns and these changes could contribute to acute or overuse injuries. However, these effects depend on which muscles are fatigued. The purpose of this study was to determine the differential effects of proximal and distal upper extremity muscle fatigue on repetitive movements. Fourteen subjects completed a repetitive ratcheting task before and after a fatigue protocol on separate days. The fatigue protocol either fatigued the proximal (shoulder flexor) or distal (finger flexor) muscles. Pre/Post changes in trunk, shoulder, elbow, and wrist kinematics were compared to determine how proximal and distal fatigue affected multi-joint movement patterns and variability. Proximal fatigue caused a significant increase (7°, p < 0.005) in trunk lean and velocity, reduced humeral elevation (11°, p < 0.005), and increased elbow flexion (4°, p < 0.01). In contrast, distal fatigue caused small but significant changes in trunk angles (2°, p < 0.05), increased velocity of wrench movement relative to the hand (17°/s, p < 0.001), and earlier wrist extension (4%, p < 0.005). Movement variability increased at proximal joints but not distal joints after both fatigue protocols (p < 0.05). Varying movements at proximal joints may help people adapt to fatigue at either proximal or distal joints. The identified differences between proximal and distal muscle fatigue adaptations could facilitate risk assessment of occupational tasks. PMID:28235005

  5. Unilateral maxillary molar distalization with zygoma-gear appliance.

    PubMed

    Kilkis, Dogan; Bayram, Mehmet; Celikoglu, Mevlut; Nur, Metin

    2012-08-01

    The aim of this study was to present the orthodontic treatment of a 15-year-old boy with a unilateral maxillary molar distalization system, called the zygoma-gear appliance. It consisted of a zygomatic anchorage miniplate, an inner bow, and a Sentalloy closed coil spring (GAC International, Bohemia, NY). A distalizing force of 350 g was used during the distalization period. The unilateral Class II malocclusion was corrected in 5 months with the zygoma-gear appliance. The maxillary left first molar showed distalization of 4 mm with an inclination of 3°. The maxillary premolars moved distally with the help of the transseptal fibers. In addition, there were slight decreases in overjet (-0.5 mm) and maxillary incisor inclination (-1°), indicating no anchorage loss from the zygoma-gear appliance. Preadjusted fixed appliances (0.022 × 0.028-in, MBT system; 3M Unitek, Monrovia, Calif) were placed in both arches to achieve leveling and alignment. After 14 months of unilateral distalization with the zygoma-gear appliance and fixed appliances, Class I molar and canine relationships were established with satisfactory interdigitation of the posterior teeth. Acceptable overjet and overbite were also achieved. This article shows that this new system, the zygoma-gear appliance, can be used for unilateral maxillary molar distalization without anchorage loss.

  6. Distal Insertions of the Biceps Femoris

    PubMed Central

    Branch, Eric A.; Anz, Adam W.

    2015-01-01

    Background: Avulsion of the biceps femoris from the fibula and proximal tibia is encountered in clinical practice. While the anatomy of the primary posterolateral corner structures has been qualitatively and quantitatively described, a quantitative analysis regarding the insertions of the biceps femoris on the fibula and proximal tibia is lacking. Purpose: To quantitatively assess the insertions of the biceps femoris, fibular collateral ligament (FCL), and anterolateral ligament (ALL) on the fibula and proximal tibia as well as establish relationships among these structures and to pertinent surgical anatomy. Study Design: Descriptive laboratory study. Methods: Dissections were performed on 12 nonpaired, fresh-frozen cadaveric specimens identifying the biceps femoris, FCL, and ALL, and their insertions on the proximal tibia and fibula. The footprint areas, orientations, and distances from relevant osseous landmarks were measured using a 3-dimensional coordinate measurement device. Results: Dissection produced 6 easily identifiable and reproducible anatomic footprints. Tibial footprints included the insertion of the ALL and an insertion of the biceps femoris (TBF). Fibular footprints included the insertion of the FCL, a distal insertion of the biceps femoris (DBF), a medial footprint of the biceps femoris (MBF), and a proximal footprint of the biceps femoris (PBF). The mean area of these footprints (95% CI) was as follows: ALL, 53.0 mm2 (38.4-67.6); TBF, 93.9 mm2 (72.0-115.8); FCL, 86.8 mm2 (72.3-101.2); DBF, 119 mm2 (91.1-146.9); MBF, 46.8 mm2 (29.0-64.5); and PBF, 215 mm2 (192.4-237.5). The mean distance (95% CI) from the Gerdy tubercle to the center of the ALL footprint was 24.3 mm (21.6-27.0) and to the center of the TBF was 22.5 mm (21.0-24.0). The center of the DBF was 8.68 mm (7.0-10.3) from the anterior border of the fibula, the center of the FCL was 14.6 mm (12.5-16.7) from the anterior border of the fibula and 20.7 mm (19.0-22.4) from the tip of the fibular

  7. An Asian Perspective on the Management of Distal Radius Fractures

    PubMed Central

    Sebastin, Sandeep J.; Chung, Kevin C.

    2012-01-01

    Synopsis There is little data with regards to the epidemiology, pathology, or management of distal radius fractures from centers in Asia. Asia includes five advanced economies, namely Hong Kong SAR, Japan, Korea, Singapore, and Taiwan and a number of emerging economies prominent among which are China, India, Malaysia, Philippines, and Thailand. This article examines the available epidemiological data from Asia, and compares the management of distal radius fractures in the advanced and emerging Asian economies and how they match up to the current management in the west. It concludes by offering solutions for improving outcomes of distal radius fractures in both the advanced and emerging economies of Asia. PMID:22554658

  8. Hyperammonaemia in a child with distal renal tubular acidosis.

    PubMed

    Seracini, D; Poggi, G M; Pela, I

    2005-11-01

    A 5-month-old girl with distal renal tubular acidosis (RTA) and hyperammonaemia that had lasted for 12 days, despite metabolic acidosis correction, is presented in this report. The patient showed failure to thrive, poor feeding, hypotonia and vomiting crisis in absence of inborn errors of metabolism. Probably, hyperammonaemia was the result of an imbalance between the increased ammonia synthesis, in response to metabolic acidosis, and the impaired ammonia excretion, typical of distal RTA. Our case confirms that hyperammonaemia may be observed in distal RTA, mimicking an inborn error of metabolism, and it underlines that hyperammonaemia may persist several days after metabolic acidosis correction.

  9. Two-wave propagation in in vitro swine distal ulna

    NASA Astrophysics Data System (ADS)

    Mano, Isao; Horii, Kaoru; Matsukawa, Mami; Otani, Takahiko

    2015-07-01

    Ultrasonic transmitted waves were obtained in an in vitro swine distal ulna specimen, which mimics a human distal radius, that consists of interconnected cortical bone and cancellous bone. The transmitted waveforms appeared similar to the fast waves, slow waves, and overlapping fast and slow waves measured in the specimen after removing the surface cortical bone (only cancellous bone). In addition, the circumferential waves in the cortical bone and water did not affect the fast and slow waves. This suggests that the fast-and-slow-wave phenomenon can be observed in an in vivo human distal radius.

  10. Computational Modeling of Distal Protection Filters

    PubMed Central

    Siewiorek, Gail M.; Finol, Ender A.

    2010-01-01

    Purpose: To quantify the relationship between velocity and pressure gradient in a distal protection filter (DPF) and to determine the feasibility of modeling a DPF as a permeable surface using computational fluid dynamics (CFD). Methods: Four DPFs (Spider RX, FilterWire EZ, RX Accunet, and Emboshield) were deployed in a single tube representing the internal carotid artery (ICA) in an in vitro flow apparatus. Steady flow of a blood-like solution was circulated with a peristaltic pump and compliance chamber. The flow rate through each DPF was measured at physiological pressure gradients, and permeability was calculated using Darcy's equation. Two computational models representing the RX Accunet were created: an actual representation of the filter geometry and a circular permeable surface. The permeability of RX Accunet was assigned to the surface, and CFD simulations were conducted with both models using experimentally derived boundary conditions. Results: Spider RX had the largest permeability while RX Accunet was the least permeable filter. CFD modeling of RX Accunet and the permeable surface resulted in excellent agreement with the experimental measurements of velocity and pressure gradient. However, the permeable surface model did not accurately reproduce local flow patterns near the DPF deployment site. Conclusion: CFD can be used to model DPFs, yielding global flow parameters measured with bench-top experiments. CFD models of the detailed DPF geometry could be used for “virtual testing” of device designs under simulated flow conditions, which would have potential benefits in decreasing the number of design iterations leading up to in vivo testing. PMID:21142490

  11. Epithelial cell fate in the nephron tubule is mediated by the ETS transcription factors etv5a and etv4 during zebrafish kidney development.

    PubMed

    Marra, Amanda N; Wingert, Rebecca A

    2016-03-15

    Kidney development requires the differentiation and organization of discrete nephron epithelial lineages, yet the genetic and molecular pathways involved in these events remain poorly understood. The embryonic zebrafish kidney, or pronephros, provides a simple and useful model to study nephrogenesis. The pronephros is primarily comprised of two types of epithelial cells: transportive and multiciliated cells (MCCs). Transportive cells occupy distinct tubule segments and are characterized by the expression of various solute transporters, while MCCs function in fluid propulsion and are dispersed in a "salt-and-pepper" fashion within the tubule. Epithelial cell identity is reliant on interplay between the Notch signaling pathway and retinoic acid (RA) signaling, where RA promotes MCC fate by inhibiting Notch activity in renal progenitors, while Notch acts downstream to trigger transportive cell formation and block adoption of an MCC identity. Previous research has shown that the transcription factor ets variant 5a (etv5a), and its closely related ETS family members, are required for ciliogenesis in other zebrafish tissues. Here, we mapped etv5a expression to renal progenitors that occupy domains where MCCs later emerge. Thus, we hypothesized that etv5a is required for normal development of MCCs in the nephron. etv5a loss of function caused a decline of MCC number as indicated by the reduced frequency of cells that expressed the MCC-specific markers outer dense fiber of sperm tails 3b (odf3b) and centrin 4 (cetn4), where rescue experiments partially restored MCC incidence. Interestingly, deficiency of ets variant 4 (etv4), a related gene that is broadly expressed in the posterior mesoderm during somitogenesis stages, also led to reduced MCC numbers, which were further reduced by dual etv5a/4 deficiency, suggesting that both of these ETS factors are essential for MCC formation and that they also might have redundant activities. In epistatic studies, exogenous RA

  12. Epithelial cell fate in the nephron tubule is mediated by the ETS transcription factors etv5a and etv4 during zebrafish kidney development

    PubMed Central

    Marra, Amanda N.; Wingert, Rebecca A.

    2016-01-01

    Kidney development requires the differentiation and organization of discrete nephron epithelial lineages, yet the genetic and molecular pathways involved in these events remain poorly understood. The embryonic zebrafish kidney, or pronephros, provides a simple and useful model to study nephrogenesis. The pronephros is primarily comprised of two types of epithelial cells: transportive and multiciliated cells (MCCs). Transportive cells occupy distinct tubule segments and are characterized by the expression of various solute transporters, while MCCs function in fluid propulsion and are dispersed in a “salt-and-pepper” fashion within the tubule. Epithelial cell identity is reliant on interplay between the Notch signaling pathway and retinoic acid (RA) signaling, where RA promotes MCC fate by inhibiting Notch activity in renal progenitors, while Notch acts downstream to trigger transportive cell formation and block adoption of an MCC identity. Previous research has shown that the transcription factor ets variant 5a (etv5a), and its closely related ETS family members, are required for ciliogenesis in other zebrafish tissues. Here, we mapped etv5a expression to renal progenitors that occupy domains where MCCs later emerge. Thus, we hypothesized that etv5a is required for normal development of MCCs in the nephron. etv5a loss of function caused a decline of MCC number as indicated by the reduced frequency of cells that expressed the MCC-specific markers outer dense fiber of sperm tails 3b (odf3b) and centrin 4 (cetn4), where rescue experiments partially restored MCC incidence. Interestingly, deficiency of ets variant 4 (etv4), a related gene that is broadly expressed in the posterior mesoderm during somitogenesis stages, also led to reduced MCC numbers, which were further reduced by dual etv5a/4 deficiency, suggesting that both of these ETS factors are essential for MCC formation and that they also might have redundant activities. In epistatic studies, exogenous RA

  13. Missense Mutation of POU Domain Class 3 Transcription Factor 3 in Pou3f3L423P Mice Causes Reduced Nephron Number and Impaired Development of the Thick Ascending Limb of the Loop of Henle.

    PubMed

    Rieger, Alexandra; Kemter, Elisabeth; Kumar, Sudhir; Popper, Bastian; Aigner, Bernhard; Wolf, Eckhard; Wanke, Rüdiger; Blutke, Andreas

    2016-01-01

    During nephrogenesis, POU domain class 3 transcription factor 3 (POU3F3 aka BRN1) is critically involved in development of distinct nephron segments, including the thick ascending limb of the loop of Henle (TAL). Deficiency of POU3F3 in knock-out mice leads to underdevelopment of the TAL, lack of differentiation of TAL cells, and perinatal death due to renal failure. Pou3f3L423P mutant mice, which were established in the Munich ENU Mouse Mutagenesis Project, carry a recessive point mutation in the homeobox domain of POU3F3. Homozygous Pou3f3L423P mutants are viable and fertile. The present study used functional, as well as qualitative and quantitative morphological analyses to characterize the renal phenotype of juvenile (12 days) and aged (60 weeks) homo- and heterozygous Pou3f3L423P mutant mice and age-matched wild-type controls. In both age groups, homozygous mutants vs. control mice displayed significantly smaller kidney volumes, decreased nephron numbers and mean glomerular volumes, smaller TAL volumes, as well as lower volume densities of the TAL in the kidney. No histological or ultrastructural lesions of TAL cells or glomerular cells were observed in homozygous mutant mice. Aged homozygous mutants displayed increased serum urea concentrations and reduced specific urine gravity, but no evidence of glomerular dysfunction. These results confirm the role of POU3F3 in development and function of the TAL and provide new evidence for its involvement in regulation of the nephron number in the kidney. Therefore, Pou3f3L423P mutant mice represent a valuable research model for further analyses of POU3F3 functions, or for nephrological studies examining the role of congenital low nephron numbers.

  14. Combined open proximal and stent-graft distal repair for distal arch aneurysms: an alternative to total debranching.

    PubMed

    Zierer, Andreas; Sanchez, Luis A; Moon, Marc R

    2009-07-01

    We present herein a novel, combined, simultaneous open proximal and stent-graft distal repair for complex distal aortic arch aneurysms involving the descending aorta. In the first surgical step, the transverse arch is opened during selective antegrade cerebral perfusion, and a Dacron graft (DuPont, Wilmington, DE) is positioned down the descending aorta in an elephant trunk-like fashion with its proximal free margin sutured circumferentially to the aorta just distal to the left subclavian or left common carotid artery. With the graft serving as the new proximal landing zone, subsequent endovascular repair is performed antegrade during rewarming through the ascending aorta.

  15. Distal Renal Tubular Acidosis in Infancy: A Bicarbonate Wasting State

    ERIC Educational Resources Information Center

    Rodriguez-Soriano, J.; And Others

    1975-01-01

    Studied were three unrelated infants with distal renal tubular acidosis (a condition characterized by an inability to acidify the urine to minimal pH levels resulting in the loss of bicarbonates). (DB)

  16. Distal femoral osteotomy using a novel deformity reduction device.

    PubMed

    Panichi, Enrico; Cappellari, Fulvio; Olimpo, Matteo; Piras, Lisa A; Radasch, Robert; Ferretti, Antonio; Peirone, Bruno

    2016-09-20

    Distal femoral osteotomy is a surgical procedure used to correct patellar luxation, secondary to a femoral deformity. A distal femoral osteotomy using the tibial plateau levelling osteotomy-jig to temporarily provide stability of the distal femoral osteotomy, maintaining limb alignment in the frontal and axial planes prior to internal plate fixation of the osteotomy, has been described. This report describes a novel jig named Deformity Reduction Device (DRD). This device was developed with the specific aim of increasing precision and predictability during corrective osteotomy execution in order to be consistent with the preoperative planning. The distal femoral osteotomy DRD-assisted procedure is described in detail, discussing the theoretical and practical principles of the application.

  17. Differential permeability of the proximal and distal rabbit small bowel

    PubMed Central

    Ross, Allan; Rubin, Allen W.; Deren, Julius J.

    1972-01-01

    The permeability of the proximal and distal rabbit intestine for two to six carbon polyhydric alcohols was compared. Intestinal segments were mounted in chambers that permitted the measurement of the unidirectional flux across the brush border membrane. For both proximal and distal intestine, the permeability for a series of polyhydric alcohols decreased with increasing size. The proximal intestine was more permeable for four, five, and six carbon polyhydric alcohols than distal intestine. This regional permeability difference can be attributed to variations in the permeability characteristics of the brush border specifically. The uptake of alcohols was nonsaturable and was not inhibited by phlorizine or n-ethylmaleimide. The results are compatible with the concept that the brush border membrane has properties similar to artificial porous membranes and that the equivalent radius of the pores of the proximal intestine exceeds that of the distal gut. PMID:4639025

  18. Endovascular Treatment of Basilar Artery Aneurysms Associated with Distal Fenestration

    PubMed Central

    Juszkat, R.; Nowak, S.; Moskal, J.; Kociemba, W.; Zarzecka, A.

    2009-01-01

    Summary Segmental non-fusion of the basilar artery results from failed fusion of the neural arteries and from regression of the bridging arteries that connect the longitudinal arteries. This condition is associated with aneurysm formation in 7% of cases. Distally unfused arteries with associated aneurysms are very rare. We report on a case of successful endovascular treatment of an aneurysm of the distally unfused basilar trunk. PMID:20465939

  19. Comparison of Chevron and Distal Oblique Osteotomy for Bunion Correction.

    PubMed

    Scharer, Brandon M; DeVries, J George

    2016-01-01

    The chevron osteotomy is a standard procedure by which bunions are corrected. One of us routinely performs a distal oblique osteotomy, which, to the best of our knowledge, has not been described for the correction of bunion deformities. The purpose of the present study was to compare the short- and medium-term results of the distal oblique and chevron osteotomies for bunion correction. We performed a retrospective clinical and radiographic comparison of patients who had undergone a distal oblique or chevron osteotomy for the correction of bunion deformity. In addition, a prospective patient satisfaction survey was undertaken. A total of 55 patients were included in the present study and were treated from January 2012 to November 2014. Of the 55 patients, 27 (49.2%) were in the chevron group and 28 (50.8%) in the distal oblique group. Radiographically, no statistically significant difference was found between the 2 groups with respect to postoperative first intermetatarsal angle (p < .0001) and hallux valgus angle (p < .0001), but a greater change was found in the intermetatarsal angle in the distal oblique group (p = .467). Prospective patient satisfaction scores were available for 33 patients (60%), 16 (29%) in the chevron group and 17 (31%) in the distal oblique group. When converting the satisfaction score to a numerical score, the chevron group scored 3.3 ± 1.1 and the distal oblique group scored 3.2 ± 0.8 (p = .812). We found that the distal oblique osteotomy used in the present study is simple and reliable and showed radiographic correction and patient satisfaction equivalent to those in the chevron osteotomy.

  20. Transient Distal Renal Tubular Acidosis in Organophosphate Poisoning

    PubMed Central

    Narayan, Ram; Abdulla, Mansoor C.; Alungal, Jemshad

    2017-01-01

    Renal complications due to organophosphate poisoning are very rare. We are presenting a unique case of transient distal renal tubular acidosis due to organophosphate poisoning, which to the best of our knowledge is the first of its kind. An elderly female after deliberate self-harm with ingestion of chlorpyrifos had multiple ventricular arrhythmias due to hypokalemia secondary to distal renal tubular acidosis which improved completely after treatment.

  1. Split cord malformation type I distal to segmental myelomeningocele

    PubMed Central

    Addas, Bassam M.

    2014-01-01

    The coexistence of myelomeningocele (MMC) and split cord malformation (SCM) is a well-known phenomenon. The SCM is usually above or at the level of the MMC. Split cord malformation distal to the MMC is considered to be the rarest form of such a combination. We report a case of SCM (type I) distal to the MMC diagnosed pre-operatively. Repair of the MMC and the SCM were carried out in the same setting. PMID:25551117

  2. Distal airway dysfunction identifies pulmonary inflammation in asymptomatic smokers

    PubMed Central

    Berger, Kenneth I.; Pradhan, Deepak R.; Goldring, Roberta M.; Oppenheimer, Beno W.; Rom, William N.

    2016-01-01

    Smoking induced inflammation leads to distal airway destruction. However, the relationship between distal airway dysfunction and inflammation remains unclear, particularly in smokers prior to the development of airway obstruction. Seven normal controls and 16 smokers without chronic obstructive pulmonary disease (COPD) were studied. Respiratory function was assessed using the forced oscillation technique (FOT). Abnormal FOT was defined as elevated resistance at 5 Hz (R5). Parameters reflecting distal lung function included frequency dependence of resistance (R5–20) and dynamic elastance (X5). Inflammation was quantified in concentrated bronchoalveolar lavage utilising cell count differential and cytokines expressed as concentration per mL epithelial lining fluid. All control subjects and seven smokers had normal R5. Nine smokers had elevated R5 with abnormal R5–20 and X5, indicating distal lung dysfunction. The presence of abnormal FOT was associated with two-fold higher lymphocyte and neutrophil counts (p<0.025) and with higher interleukin (IL)-8, eotaxin and fractalkine levels (p<0.01). Reactivity of R5–20 and X5 correlated with levels of IL-8, eotaxin, fractalkine, IL-12p70 and transforming growth factor-α (r>0.47, p<0.01). Distal airway dysfunction in smokers without COPD identifies the presence of distal lung inflammation that parallel reported observations in established COPD. These findings were not evident on routine pulmonary function testing and may allow the identification of smokers at risk of progression to COPD. PMID:27995132

  3. Distal attribution and distance perception in sensory substitution

    PubMed Central

    Siegle, Joshua H.; Warren, William H.

    2013-01-01

    In sensory substitution, the user may be directly aware of distal objects, as in everyday perception, or make explicit cognitive inferences based on an awareness of the proximal stimulation. Anecdotal evidence supports the experience of distal attribution, but so far there have been few rigorous experimental tests of the claim. In this study, blindfolded participants observed a target light using a device consisting of a finger-mounted photodiode that drives tactile vibration on the back. With the blindfold off and the target removed, participants moved a reference object to match the perceived egocentric distance of the target. Participants who were instructed to attend to the distal target improved significantly during two hours of practice, whereas those instructed to attend to proximal variables showed no improvement. Unsigned error increased with ratings of proximal attention but decreased with ratings of target object solidity, consistent with distal attribution. Performance transferred to the non-dominant arm and to a rotated body orientation, demonstrating that learning did not depend on a joint-specific sensorimotor relationship between target distance and arm configuration. The results experimentally confirm that distal attribution can occur in sensory substitution, based on a perceptual strategy rather than an explicit cognitive strategy. Moreover, they suggest that the informational basis for distal attribution is not a joint-specific sensorimotor relation, but a more abstract spatial invariant. PMID:20402243

  4. Distal airway dysfunction identifies pulmonary inflammation in asymptomatic smokers.

    PubMed

    Berger, Kenneth I; Pradhan, Deepak R; Goldring, Roberta M; Oppenheimer, Beno W; Rom, William N; Segal, Leopoldo N

    2016-10-01

    Smoking induced inflammation leads to distal airway destruction. However, the relationship between distal airway dysfunction and inflammation remains unclear, particularly in smokers prior to the development of airway obstruction. Seven normal controls and 16 smokers without chronic obstructive pulmonary disease (COPD) were studied. Respiratory function was assessed using the forced oscillation technique (FOT). Abnormal FOT was defined as elevated resistance at 5 Hz (R5). Parameters reflecting distal lung function included frequency dependence of resistance (R5-20) and dynamic elastance (X5). Inflammation was quantified in concentrated bronchoalveolar lavage utilising cell count differential and cytokines expressed as concentration per mL epithelial lining fluid. All control subjects and seven smokers had normal R5. Nine smokers had elevated R5 with abnormal R5-20 and X5, indicating distal lung dysfunction. The presence of abnormal FOT was associated with two-fold higher lymphocyte and neutrophil counts (p<0.025) and with higher interleukin (IL)-8, eotaxin and fractalkine levels (p<0.01). Reactivity of R5-20 and X5 correlated with levels of IL-8, eotaxin, fractalkine, IL-12p70 and transforming growth factor-α (r>0.47, p<0.01). Distal airway dysfunction in smokers without COPD identifies the presence of distal lung inflammation that parallel reported observations in established COPD. These findings were not evident on routine pulmonary function testing and may allow the identification of smokers at risk of progression to COPD.

  5. A 2D model of axial symmetry for proximal tubule of an average human nephron: indicative results of diffusion, convection and absorption processes

    NASA Astrophysics Data System (ADS)

    Insfrán, J. F.; Ubal, S.; Di Paolo, y. J.

    2016-04-01

    A simplified model of a proximal convoluted tubule of an average human nephron is presented. The model considers the 2D axisymmetric flow of the luminal solution exchanging matter with the tubule walls and the peritubular fluid by means of 0D models for the epithelial cells. The tubule radius is considered to vary along the conduit due to the trans-epithelial pressure difference. The fate of more than ten typical solutes is tracked down by the model. The Navier-Stokes and Reaction-Diffusion-Advection equations (considering the electro-neutrality principle) are solved in the lumen, giving a detailed picture of the velocity, pressure and concentration fields, along with trans-membrane fluxes and tubule deformation, via coupling with the 0D model for the tubule wall. The calculations are carried out numerically by means of the finite element method. The results obtained show good agreement with those published by other authors using models that ignore the diffusive transport and disregard a detailed calculation of velocity, pressure and concentrations. This work should be seen as a first approach towards the development of a more comprehensive model of the filtration process taking place in the kidneys, which ultimately helps in devising a device that can mimic/complement the renal function.

  6. Degree and Predictors of Functional Loss of the Operated Kidney following Nephron-Sparing Surgery: Assessment by Quantitative SPECT of 99m Tc-Dimercaptosuccinic Acid Scintigraphy

    PubMed Central

    Nativ, Ofer; Levi, Amos; Farfara, Roy; Halachmi, Sarel; Moskovitz, Boaz

    2011-01-01

    Purpose. To determine the degree and predictors of renal function loss of the operated kidney following nephron-sparing surgery (NSS). Material and methods. The study group included 113 patients with renal mass who underwent NSS at our institution. QDMSA before and 3–6 months after surgery was used for evaluation differences in renal function of each kidney. Mean change of percent uptake by the kidney was correlated with various clinical and pathological variables. Results. The overall average decrease of renal function of the operated kidney as measured by QDMSA was 10.5% ± 2.6 SER. Among the studied variables, the most important predictors of postoperative ipsilateral residual kidney function were estimated blood loss (EBL), P = 0.0003, duration of warm ischemia, P = 0.008, patient's age at surgery, P = 0.024, method used for tumor bed closure, P = 0.06, and location of the lesion, P = 0.08. Conclusions. Carful hemostasis, minimal duration of arterial clamping, and use of tissue adhesives to seal tumor bed are associated with maximal preservation of postoperative residual renal function after NSS. These variables should be considered by the operative team when planning the surgical procedure . PMID:21845188

  7. Arthroplasty of the distal ulna distal in managing patients with post-traumatic disorders of the distal radioulnar joint: measurement of quality of life☆

    PubMed Central

    Aita, Marcio Aurélio; Ibanez, Daniel Schneider; Saheb, Gabriel Cunha Barbosa; Alves, Rafael Saleme

    2015-01-01

    Objective To measure the quality of life and clinical–functional results from patients diagnosed with osteoarthrosis of the distal radioulnar joint who underwent surgical treatment using the technique of total arthroplasty of the ulna, with a total or partial Ascension® prosthesis of the distal ulna. Methods Ten patients were evaluated after 12 months of follow-up subsequent to total or partial arthroplasty of the distal ulna. All of them presented post-traumatic osteoarthrosis and/or chronic symptomatic instability of the distal radioulnar joint. The study was prospective. Seven patients had previously undergone wrist procedures (two cases with Darrach, three with Sauvé–Kapandji and two with ligament reconstruction of the fibrocartilage complex) and three presented fractures of the distal ulna that evolved with pain, instability and osteoarthrosis of the distal radioulnar joint. The following were assessed: quality of life (DASH scale); percentage degree of palm grip strength (kgf) and pronosupination range of motion in relation to the unaffected side; pain (VAS); return to work; subjective evaluation of radiography; and complications. Results The patients presented a mean range of motion of 174.5° (normal side: 180°). Quality of life was analyzed by applying the DASH questionnaire and the mean value found was 5.9. The mean pain score using the VAS was 2.3. The mean degree of palm grip strength (kgf) was 50.7, which represented 90.7% of the strength on the unaffected side. The complication rate was 10%: this patient presented slight dorsal instability of the ulna and persistent pain, and did not return to work. This patient is still being followed up in the outpatient clinic and occupational therapy sector, with little improvement. He does not wish to undergo a new procedure. The mean length of follow-up was 16.8 months, with a minimum of 10 and maximum of 36 months. Conclusion This concept is subject to the test of time. Implantation of a prosthesis is a

  8. The distal classification and management of choledochal cyst in adults

    PubMed Central

    Liu, Yanfeng; Sun, Jingxian; Guo, Sen; Liu, Zengli; Zhu, Min; Zhang, Zong-li

    2017-01-01

    Abstract Todani classification is extensively used to guide the surgical strategy of choledochal cysts, but no systematic investigations on the distal management of intrapancreatic choledochal cysts have been conducted. This study reports the distal classification and management of choledochal cysts in adults based on the relation between the cyst and pancreatic duct. Patients with choledochal cyst who underwent operation, including distal management, in our department from January 2009 to December 2014 were retrospectively reviewed. Patients presenting symptoms, coexisting diseases, surgical treatment, perioperative complications, and long-term follow-up according to the distal classification of choledochal cyst were analyzed. A total of 54 patients with choledochal cyst were included in the present retrospective study. Based on the distal classification of choledochal cyst, 39 patients (72.22%) were type 1, 13 patients (24.07%) were type 2, and 2 patients (3.70%) were type 3. Thirty-nine type 1 patients and 10 type 2 patients underwent excision of intrapancreatic choledochal cyst or bile duct. Three type 2 patients received excision of distal cylindrical cyst and papilla, followed by pancreatic duct plasty with duodenum mucosa. One type 3 patient underwent endoscopic sphincteroplasty, and another type 3 patient underwent transduodenal sphincteroplasty. After the operation, 11 patients (20.37%, 11/54) had short-term perioperative complications. The long-term follow-up results showed that the satisfactory rate (excellent and good outcomes) was 95.83%. Current distal classification of choledochal cysts could provide a more targeted strategy for complete excision to eliminate potential dead space within the pancreas, protect the pancreatic duct, and prevent reoperation. PMID:28328818

  9. Distal gap junctions and active dendrites can tune network dynamics.

    PubMed

    Saraga, Fernanda; Ng, Leo; Skinner, Frances K

    2006-03-01

    Gap junctions allow direct electrical communication between CNS neurons. From theoretical and modeling studies, it is well known that although gap junctions can act to synchronize network output, they can also give rise to many other dynamic patterns including antiphase and other phase-locked states. The particular network pattern that arises depends on cellular, intrinsic properties that affect firing frequencies as well as the strength and location of the gap junctions. Interneurons or GABAergic neurons in hippocampus are diverse in their cellular characteristics and have been shown to have active dendrites. Furthermore, parvalbumin-positive GABAergic neurons, also known as basket cells, can contact one another via gap junctions on their distal dendrites. Using two-cell network models, we explore how distal electrical connections affect network output. We build multi-compartment models of hippocampal basket cells using NEURON and endow them with varying amounts of active dendrites. Two-cell networks of these model cells as well as reduced versions are explored. The relationship between intrinsic frequency and the level of active dendrites allows us to define three regions based on what sort of network dynamics occur with distal gap junction coupling. Weak coupling theory is used to predict the delineation of these regions as well as examination of phase response curves and distal dendritic polarization levels. We find that a nonmonotonic dependence of network dynamic characteristics (phase lags) on gap junction conductance occurs. This suggests that distal electrical coupling and active dendrite levels can control how sensitive network dynamics are to gap junction modulation. With the extended geometry, gap junctions located at more distal locations must have larger conductances for pure synchrony to occur. Furthermore, based on simulations with heterogeneous networks, it may be that one requires active dendrites if phase-locking is to occur in networks formed

  10. The role of pendrin in blood pressure regulation

    PubMed Central

    2015-01-01

    Pendrin is a Na+-independent Cl−/HCO3− exchanger found in the apical regions of type B and non-A, non-B intercalated cells within the aldosterone-sensitive region of the nephron, i.e., the distal convoluted tubule (DCT), the connecting tubule (CNT), and the cortical collecting duct (CCD). Type B intercalated cells mediate Cl− absorption and HCO3− secretion primarily through pendrin-mediated Cl−/HCO3− exchange. This exchanger is upregulated with angiotensin II administration and in models of metabolic alkalosis, such as following administration of aldosterone or NaHCO3. In the absence of pendrin-mediated HCO3− secretion, an enhanced alkalosis is observed following aldosterone or NaHCO3 administration. However, probably of more significance is the role of pendrin in the pressor response to aldosterone. Pendrin mediates Cl− absorption and modulates aldosterone-induced Na+ absorption mediated by the epithelial Na channel (ENaC). Pendrin changes ENaC activity by changing both channel open probability (Po) and surface density (N), at least partly by altering luminal HCO3− and ATP concentration. Thus aldosterone and angiotensin II stimulate pendrin expression and function, which stimulates ENaC activity, thereby contributing to the pressor response of these hormones. However, pendrin may modulate blood pressure partly through its extrarenal effects. For example, pendrin is expressed in the adrenal medulla, where it modulates catecholamine release. The increase in catecholamine release observed with pendrin gene ablation likely contributes to the increment in vascular contractile force observed in the pendrin null mouse. This review summarizes the signaling mechanisms that regulate pendrin abundance and function as well as the contribution of pendrin to distal nephron function. PMID:26538443

  11. Ejecta emplacement: from distal to proximal

    NASA Astrophysics Data System (ADS)

    Artemieva, N.

    2008-09-01

    Introduction Most part of impact ejecta is deposited ballistically at some distance from a crater, defined by ejection velocity V and ejection angle α: d=v2sinα/g. In case of giant impacts, planetary curvature should be taken into account [1]. Combined with ejecta scaling [2], these relations allow to define ejecta thickness as a function of distance. Ejecta from large craters are deposited at velocity high enough to mobilize substrate material and to thicken ejecta deposits [3]. Ballistic approximation is valid for airless bodies (if impact vaporization is not vast) or for proximal ejecta of large impact craters, where ejecta mass per unit area is substantially greater than the mass of involved vapor/atmosphere (M-ratio). Deposition of distal ejecta, in which ejecta mass is negligible compared to the atmosphere, may be also treated in a simplified manner, i.e. as 1) passive motion of ejected particles within an impact plume and 2) later, as sedimentation of particles in undisturbed atmosphere (equilibrium between gravity and drag). In all intermediate M-ratio values, impact ejecta move like a surge, i.e. dilute suspension current in which particles are carried in turbulent flows under the influence of gravity. Surges are well-known for near-surface explosive tests, described in detail for volcanic explosions (Plinian column collapse, phreato-magmatic eruption, lateral blast), and found in ejecta from the Chicxulub [4] and the Ries [5]. Important aspects of surge transport include its ability to deposit ejecta over a larger area than that typical of continuous ballistic ejecta and to create multiple ejecta layers. Numerical model Two-phase hydrodynamics. Surges should be modeled in the frame of two-phase hydrodynamics, i.e. interaction between solid/molten particles and atmospheric gas/impact vapor should be taken into account. There are two techniques of solving equations for dust particle motion in a gas flow. The first one describes solid/molten particles as a

  12. A New Orthodontic Appliance with a Mini Screw for Upper Molar Distalization

    PubMed Central

    2016-01-01

    The aim of this study is to present a new upper molar distalization appliance called Cise distalizer designed as intraoral device supported with orthodontic mini screw for upper permanent molar distalization. The new appliance consists of eight main components. In order to understand the optimum force level, the appliance under static loading is tested by using strain gage measurement techniques. Results show that one of the open coils produces approximately 300 gr distalization force. Cise distalizer can provide totally 600 gr distalization force. This range of force level is enough for distalization of upper first and second molar teeth. PMID:27528796

  13. An intrinsic timer specifies distal structures of the vertebrate limb

    PubMed Central

    Saiz-Lopez, Patricia; Chinnaiya, Kavitha; Campa, Victor M.; Delgado, Irene; Ros, Maria A.; Towers, Matthew

    2015-01-01

    How the positional values along the proximo-distal axis (stylopod-zeugopod-autopod) of the limb are specified is intensely debated. Early work suggested that cells intrinsically change their proximo-distal positional values by measuring time. Recently, however, it is suggested that instructive extrinsic signals from the trunk and apical ectodermal ridge specify the stylopod and zeugopod/autopod, respectively. Here, we show that the zeugopod and autopod are specified by an intrinsic timing mechanism. By grafting green fluorescent protein-expressing cells from early to late chick wing buds, we demonstrate that distal mesenchyme cells intrinsically time Hoxa13 expression, cell cycle parameters and the duration of the overlying apical ectodermal ridge. In addition, we reveal that cell affinities intrinsically change in the distal mesenchyme, which we suggest results in a gradient of positional values along the proximo-distal axis. We propose a complete model in which a switch from extrinsic signalling to intrinsic timing patterns the vertebrate limb. PMID:26381580

  14. Complications of Minimally Invasive Percutaneous Plating for Distal Tibial Fractures

    PubMed Central

    Muzaffar, Nasir; Bhat, Rafiq; Yasin, Mohammad

    2016-01-01

    Background The management of distal tibia fractures continues to remain a source of controversy and debate. Objectives The aim of this study was to evaluate the various complications of minimally invasive percutaneous plate osteosynthesis (MIPPO) using a locking plate for closed fractures of distal tibia in a retrospective study. Patients and Methods Twenty-five patients with distal tibial fractures, treated by minimally invasive percutaneous plate osteosynthesis, were evaluated in a retrospective study. We studied the rate, probable etiological factors and preventive and corrective measures of various complications associated with minimally invasive plating of distal tibia. Results Mean age of the patients was 41.16 years (range 22 - 65). There were 13 male and 12 female patients. All fractures united at an average duration of 16.8 weeks. There were two cases of superficial and two cases of deep infection, and deep infections required removal of hardware for cure. There were four cases of ankle stiffness, most of them occurring in intra-articular fractures, three cases of palpable implant, three cases of malunion, one case of loss of reduction and one patient required reoperation. The average AO foot and ankle score was 83.6. Conclusions We found MIPPO using locking plate to be a safe and effective method for the treatment of distal tibial fractures in properly selected patients yet can result in a variety of complications if proper precautions before, during and after surgery are not taken care of. PMID:28182170

  15. Distal Radius Radiographic Indices and Perilunate Fracture Dislocation

    PubMed Central

    Bagherifard, Abolfazl; Jafari, Davod; Keihan Shokouh, Hassan; Motavallian, Ebrahim; Najd Mazhar, Farid

    2016-01-01

    Background Distal radius radiographic indices may play a role as risk factors in pathogenesis of Kienbock’s disease, scaphoid fracture and nonunion. Perilunate fracture dislocations are devastating wrist injuries, and their relationship and distal radius indices have not been addressed in the literature. Objectives The aim of this study was to evaluate the possible role of distal radius radiographic indices including radial height, radial inclination, ulnar variance and volar tilt as risk factors in the perilunate fracture dislocation injury of the wrist. Patients and Methods We studied distal radius radiographic indices including radial height, radial inclination, ulnar variance and volar tilt in 43 patients with perilunate fracture dislocations and compared them with 44 wrists in the control group. Results The mean values of the radial height, radial inclination, ulnar variance and volar tilt were 12.74 (5 - 18), 24.20 (7 - 35), -0.73 (-5 - 4) and 12.28 (2 - 20) in the patient group. These values were 12.68 (9 - 22), 23.22 (17 - 30), -0.11 (-4 - 3) and 11.05 (-3 - 20), respectively in the control group. There was no statistically significant difference between the two groups. Conclusions This study did not show that distal radius anatomical indices including the radial height, radial inclination, ulnar variance and volar tilt influence perilunate fracture dislocation as risk factors. PMID:27626004

  16. Far cortical locking screws in distal femur fractures.

    PubMed

    Adams, John D; Tanner, Stephanie L; Jeray, Kyle J

    2015-03-01

    Distal femur fractures routinely heal by secondary bone healing, which relies on interfragmentary motion. Periarticular locking plates are commonly used for fixation in distal femur fractures but are associated with a high nonunion rate, likely due to the stiffness of the constructs. Far cortical locking (FCL) screws are designed to allow micromotion at the near cortex while maintaining purchase in only the far cortex. Although clinical data are limited, these screws have been shown in biomechanical studies to provide excellent interfragmentary motion, and animal models have shown increased callus formation compared with traditional locking screws. The purpose of this study was to examine the clinical effects that FCL screws have on healing in distal femur fractures treated with locked constructs. In this retrospective case series, 15 patients with a distal femur fracture treated with MotionLoc screws (Zimmer, Warsaw, Indiana) were analyzed. Serial radiographs were evaluated for callus presence and time to union. All fractures were either 33-A3 or 33-C2 according to the AO classification system, and 5 (33%) were open. Bone loss was recorded in 2 patients. There were no nonunions, and average time to union was 24 weeks. There were no implant failures, and all 5 open fractures, including the 2 with bone loss, healed without intervention. There was 1 reoperation due to painful hardware. Although this is a small case series, these results are promising. Far cortical locking screws may provide the answer to the high nonunion rate associated with distal femur fractures treated with traditional locked constructs.

  17. Accuracy of distal radius positioning using an anatomical plate.

    PubMed

    Vroemen, Joy C; Dobbe, Johannes G G; Sierevelt, Inger N; Strackee, Simon D; Streekstra, Geert J

    2013-04-01

    Over the past decade, several anatomical plates have been introduced to improve the result of open reduction and internal fixation of the distal radius. Using 3-dimensional imaging techniques, the authors studied the accuracy and reproducibility of distal radius positioning using anatomical plates.Distal radius fractures and the correction of these fractures were simulated with plastic bone models of radii. The authors simulated a defect by removing an arbitrary wedge shape from the artificial radii. Two surgeons corrected these fractures by placing 2 anatomical plate types according to the plate manufacturers' instructions. The residual positioning errors of the distal segment in relation to the unaffected radii were determined using 3-dimensional imaging and were compared with naturally occurring bilateral radius differences in healthy individuals. In many cases, positioning does not agree with differences based on bilateral asymmetry in healthy patients.This study indicated the accuracy of anatomical plates. Positioning an anatomical plate may lead to considerable residual errors in individual patients. Volar distal radius plate shapes differ among plate manufacturers. Therefore, one plate may perform better than another in an individual.

  18. Clinicopathological features of carcinoma of the distal penile urethra.

    PubMed

    Corbishley, Catherine M; Rajab, Ramzi M; Watkin, Nicholas A

    2015-05-01

    Distal urethral carcinomas are very rare and are similar in their pathology and behaviour to tumours of the glans penis and foreskin. Similarly they are associated with penile intraepithelial neoplasia (PeIN) of both differentiated and undifferentiated types. Current management is mainly surgical, but increasingly involves specialist penile-preserving techniques. Handling and dissection of the specimens is broadly the same as other primary penile tumours. The prognosis of distal urethral lesions is believed to be worse than penile tumours and better than prostatic urethral tumours, but the evidence is sparse. The staging system for urethral tumours does not distinguish between proximal and distal, apart from prostatic urethra, and has led to much confusion in the literature. Although the subtypes of tumours seen in the distal urethra are the same as those on the glans and foreskin, there is an increased proportion of basaloid squamous carcinoma and malignant melanoma whereas the majority of tumours seen in the proximal and prostatic urethra are of urothelial origin. In future, distal urethral tumours should be separately designated with site-specific staging/TNM and reporting system and pathologically classified in the same way as penile and foreskin tumours. Ultimately, this will improve the quality of data and produce evidence to inform management.

  19. Implant Size Availability Affects Reproduction of Distal Femoral Anatomy.

    PubMed

    Morris, William Z; Gebhart, Jeremy J; Goldberg, Victor M; Wera, Glenn D

    2016-07-01

    A total knee arthroplasty system offers more distal femoral implant anterior-posterior (AP) sizes than its predecessor. The purpose of this study is to investigate the impact of increased size availability on an implant system's ability to reproduce the AP dimension of the native distal femur. We measured 200 cadaveric femora with the AP-sizing guides of Zimmer (Warsaw, IN) NexGen (8 sizes) and Zimmer Persona (12 sizes) total knee arthroplasty systems. We defined "size deviation" as the difference in the AP dimension between the anatomic size of the native femur and the closest implant size. We defined satisfactory reproduction of distal femoral dimensions as < 1 mm difference between the implant and native femur size. The NexGen system was associated with a mean 0.46 mm greater implant size deviation than Persona (p < 0.001). When using a 1 mm size deviation as a cutoff for satisfactory replication of the native distal femoral anatomy, 85/200 specimens (42.5%) were a poor fit by NexGen, but a satisfactory fit by Persona. Only 1/200 specimens (0.5%) was a poor fit by Persona, but a satisfactory fit by NexGen (p < 0.001). The novel knee system with 12 versus 8 sizes reproduces the AP dimension of the native distal femur more closely than its predecessor. Further study is needed to determine the clinical impact of these differences.

  20. Segmental high amplitude peristaltic contractions in the distal esophagus.

    PubMed

    Freidin, N; Mittal, R K; Traube, M; McCallum, R W

    1989-06-01

    High amplitude peristaltic contractions in the distal esophagus ("nutcracker esophagus") is the most common manometric disorder seen in patients with noncardiac chest pain. Although this abnormality is found in the distal esophagus, the definition regarding its precise level in the esophagus is unclear. A careful analysis of 99 consecutive manometric tracings performed during a 1-yr period revealed that in patients with noncardiac chest pain and/or dysphagia, the location of the abnormal esophageal contractions varied: 1) in 11 patients the esophageal contractions were abnormal at 2 cm, as well as 7 cm, above the lower esophageal sphincter (LES); 2) the abnormality was limited to the 2-cm location above the LES in six patients; and 3) was confined to the 7-cm location above the LES in five patients. If the conventional criteria of averaging the distal esophageal contraction amplitudes at 2 and 7 cm above the LES were adopted, six of the 11 patients with segmental esophageal contraction abnormality would not have been identified. We suggest that, by inspection of each location of the distal esophagus separately, localized high amplitude contractions can be identified, and the distal 2 cm segment of the esophagus should be routinely included in the manometric evaluation.

  1. [Diagnostic of group A streptococcal blistering distal dactylitis].

    PubMed

    Cohen, R; Levy, C; Cohen, J; Corrard, F; Deberdt, P; Béchet, S; Bonacorsi, S; Bidet, Ph

    2014-11-01

    Blistering distal dactylitis is a distinct clinical entity, generally due to S. pyogenes, unfrequently reported. Characteristically, blistering distal dactylitis is described as a localized infection involving the distal phalanx of the digits, and it usually presents as a fluid-filled blister. Between October 2009 and June 2014, 69 children (median age: 60 months, extremes: 0,6-176) were enrolled. The sensitivity of GAS rapid antigen detection test was 97 % (CI 95 %: 83-100 %), the specificity was 76 % (CI 95 %: 60-89 %), the negative predictive value was 97 % (CI 95 %: 83-100 %), and the positive predictive value 76 % (CI 95 %: 60-89 %). All patients with a positive GAS rapid antigen test were treated with antibiotics (amoxicillin essentially) and cured without surgery.

  2. Whole Exome Sequencing Identifies Atypical Welander Distal Myopathy in Patient

    PubMed Central

    Blackburn, Patrick; Jackson, Jessica; Harris, Kimberly; Selcen, Duygu; Dimberg, Elliot; Atwal, Paldeep

    2017-01-01

    Abstract Welander distal myopathy is a rare autosomal dominant disorder characterized by muscle weakness in the hands and feet. Exome sequencing of affected families discovered a segregating p.Glu384Lys pathogenic variant in TIA-1 as the main genetic cause of Welander distal myopathy. TIA-1 encodes an RNA-binding protein which serves as a key component of stress granules. This protein also regulates splicing and translation of mRNA. Our patient developed progressive weakness in his hands and feet during his late 40s that was misdiagnosed as a neuropathy that caused muscle atrophy. Follow-up genetic testing revealed a p.Glu384Lys pathogenic variant in TIA-1, and he was then diagnosed with Welander distal myopathy. Our case report underlines the importance of electrodiagnostic and genetic testing of patients. PMID:28221306

  3. Molar distalization with the assistance of Temporary Anchorage Devices.

    PubMed

    Palencar, Adrian J

    2015-01-01

    This article describes efficient techniques for distalization of maxillary and mandibular molars with the assistance of Temporary Anchorage Devices (TADs). There are numerous occasions where the distalization of molars is required in lieu of the odontectomy of bicuspids. In the past, extra-oral force has been used, (i.e. Cervical or Combination Head Gear, or intra-oral force, i.e. Posterior Sagittal Appliance, Modified Greenfield Appliance, Williams DMJ 20001, CD Distalizer, Magill Sagittal, Pendulum Appliance, etc.). All the intra-oral appliances have a common denominator the orthodontic clinician has to deal with, the undesirable expression of the Third Law of Newton. The utilization of TADs allows us to circumvent this shortcoming, establishing an absolute anchorage, and thus completely negate the expression of the Third Law of Newton.

  4. [Proximal and distal rupture of the m. biceps brachii].

    PubMed

    Lorbach, O; Kieb, M; Grim, C; Engelhardt, M

    2010-12-01

    Ruptures of the biceps tendon account for a high percentage of tendon ruptures. The aetiology of proximal ruptures of the long head of the biceps tendon is often degenerative and they are frequently associated with lesions of the rotator cuff. The clinical findings are often not specific and long lasting. Distal ruptures of the biceps tendon mostly occur during eccentric contraction of the biceps muscle.Clinical tests, the associated haematoma and a distalisation or proximalisation of the muscle belly in combination with ultrasound or MRI to rule out combined diseases lead to the diagnosis. The possible options include conservative and operative treatment. Tenotomy and tenodesis lead to comparable results in the literature. Therefore, conservative treatment is mostly recommended in proximal ruptures. Operative treatment is preferred in distal ruptures of the biceps tendon in order to achieve an anatomical reconstruction of the muscle function. Chronic ruptures of the distal biceps tendon can be successfully treated with free autografts or allografts.

  5. Intramedullary Tibial Nail Fixation of Simple Intraarticular Distal Tibia Fractures.

    PubMed

    Scolaro, John A; Broghammer, Francis H; Donegan, Derek J

    2016-11-01

    The optimal treatment strategy for distal tibia fractures, especially those with intraarticular extension, remains controversial. Although open reduction and internal fixation with a plate and screw device is commonly performed for these injuries, the risk of soft tissue complications using this approach is significant. Staged treatment protocols and alternative means of fixation have been proposed to address these undesired events. Although potentially more technically demanding than fixation of diaphyseal or extraarticular tibial fractures, intramedullary nail (IMN) fixation of simple intraarticular distal tibia fractures is a viable treatment alternative with unique advantages. This article presents a review of the literature and rationale for intramedullary tibial nail fixation of simple intraarticular distal tibia fractures and a surgical approach commonly utilized for successful implementation.

  6. Two-stitch technique for distal shaft hypospadias repair.

    PubMed

    Herman, Oscar; Heller, Lior; Dorenbaum, Arye; Westreich, Melvyn

    2002-02-01

    The authors present a new technique for distal shaft hypospadias repair using a flip flap fashioned with only two stitches. In raising the flap, the tissues lateral and proximal to the flap are undermined but there is no undermining beneath the flap. The flap is sutured up to the glans with two 4-0 Vicryl sutures. No sutures are placed at the lateral edges of the flap to create the "tube" of the neo-urethra, and no postoperative urinary drainage is used. Thirty-three children with distal shaft hypospadias underwent the "two-stitch" flip flap operation. The complications were one fistula and one case of urinary retention. The technique is an easy method for reconstructing distal penile hypospadias with a very low rate of complications and is suitable for an outpatient surgical setting.

  7. Special Morphological Features at the Interface of the Renal Stem/Progenitor Cell Niche Force to Reinvestigate Transport of Morphogens During Nephron Induction

    PubMed Central

    Minuth, Will W.; Denk, Lucia

    2016-01-01

    Abstract Formation of a nephron depends on reciprocal signaling of different morphogens between epithelial and mesenchymal cells within the renal stem/progenitor cell niche. Previously, it has been surmised that a close proximity exists between both involved cell types and that morphogens are transported between them by diffusion. However, actual morphological data illustrate that mesenchymal and epithelial stem/progenitor cell bodies are separated by a striking interface. Special fixation of specimens by glutaraldehyde (GA) solution including cupromeronic blue, ruthenium red, or tannic acid for electron microscopy depicts that the interface is not void but filled in extended areas by textured extracellular matrix. Surprisingly, projections of mesenchymal cells cross the interface to contact epithelial cells. At those sites the plasma membranes of a mesenchymal and an epithelial cell are connected via tunneling nanotubes. Regarding detected morphological features in combination with involved morphogens, their transport cannot longer be explained solely by diffusion. Instead, it has to be sorted according to biophysical properties of morphogens and to detected environment. Thus, the new working hypothesis is that morphogens with good solubility such as glial cell line-derived neurotrophic factor (GDNF) or fibroblast growth factors (FGFs) are transported by diffusion. Morphogens with minor solubility such as bone morphogenetic proteins (BMPs) are secreted and stored for delivery on demand in illustrated extracellular matrix. In contrast, morphogens with poor solubility such as Wnts are transported in mesenchymal cell projections along the plasma membrane or via illustrated tunneling nanotubes. However, the presence of an intercellular route between mesenchymal and epithelial stem/progenitor cells by tunneling nanotubes also makes it possible that all morphogens are transported this way. PMID:26862472

  8. Reverse telescoping in distal skarns at Campiglia Marittima (Italy)

    NASA Astrophysics Data System (ADS)

    Vezzoni, Simone; Dini, Andrea; Rocchi, Sergio

    2014-05-01

    Skarn deposits commonly results from the metasomatic alteration of a rock, usually carbonate-rich, by infiltration of hydrothermal fluids. Most carbonate-hosted skarn deposits show a direct spatial relationship with magmatic intrusions and an intimate relationship with porphyry copper deposits. Their primary mineralogical and geochemical features indicate metasomatism by high-temperature magmatic fluids. Conversely, many distal Pb-Zn-Ag skarns pose an important challenge because there is no apparent association with magmatic intrusions and external, meteoric and/or basinal fluids should become increasingly dominant with increasing distance from the igneous source. Nevertheless recent investigation of distal skarn deposits indicates that ore-forming fluids match the composition of proximal magmatic fluids in granitoid-related mineral deposits. Besides that metal producer (Pb, Zn, Ag, Cu, Fe, W, Sn), skarn deposits can be key to understanding fluid dynamics at the periphery of magmatic-hydrothermal systems, unraveling pathways to hidden ore deposits (e.g porphyry copper). In this scenario, research on distal skarns opens new perspectives for deep mineral exploration and/or modeling of intrusion centered geothermal systems, because they should represent the outer limit of the hydrothermal system dominated by magmatic aqueous fluids. Here we present exceptional evidences from a distal Pb-Zn-Ag skarn deposit in Campiglia Marittima, Italy, where the magma, after having released the metasomatic fluids, fled up chasing its own fluid stream and invading large pockets of the newly formed skarn bodies at shallower level. Detailed underground mapping and petrologic data indicate that, after the formation of a typical distal Pb-Zn-Ag skarn, the intrusion of the parent magma produced prograde reactions in the skarn silicates, mobilization of the Pb-Zn-Ag sulfides and precipitation of a new Cu-Fe sulfide assemblage. This is a very unusual case of reverse telescoping during which

  9. A practical guide to the management of distal ulcerative colitis.

    PubMed

    Ardizzone, S; Bianchi Porro, G

    1998-04-01

    This article reviews the role of corticosteroids, sulfasalazine and mesalazine (5-aminosalicylic acid, mesalamine), immunosuppressive agents and alternative novel drugs for the treatment of distal ulcerative colitis. Short cycles of traditional, rectally administered corticosteroids (methylprednisolone, betamethasone, hydrocortisone) are effective for the treatment of mild to moderately active distal ulcerative colitis. In this context, their systemic administration is limited to patients who are refractory to either oral 5-amino-salicylates, topical mesalazine or topical corticosteroids. Of no value in maintaining remission, the long term use of either or topical corticosteroids may be hazardous. A new class of topically acting corticosteroids [budesonide, fluticasone, beclomethasone dipropionate, prednisolone-21-methasulphobenzoate, tixocortol (tixocortol pivalate)] represents a valid alternative for the treatment of active ulcerative colitis, and may be useful in the treatment of refractory distal ulcerative colitis. Although there is controversy concerning dosage or duration of therapy, oral and topical mesalazine is effective in the treatment of mild to moderately active distal ulcerative colitis. Sulfasalazine and mesalazine remain the first-choice drugs for the maintenance therapy of distal ulcerative colitis. Evidence exists showing a trend to a higher remission rate with higher doses of oral mesalazine. Topical mesalazine (suppositories or enemas) also is effective in maintenance treatment. For patients with chronically active or corticosteroid-dependent disease, azathioprine and mercaptopurine are effective in reducing either the need for corticosteroids or clinical relapses. Moreover, they are effective for long term maintenance remission. Cyclosporin may be useful in inducing remission in patients with acutely severe disease who do not achieve remission with an intensive intravenous regimen. Existing data suggest that azathioprine and mercaptopurine may

  10. Unstable Distal Radius Fractures Treated by Volar Locking Anatomical Plates

    PubMed Central

    Jose, Anto; Deniese, Pascal Noel; Babu, Abey Thomas; Rengasamy, Kanagasabai; Najimudeen, Syed

    2017-01-01

    Introduction Fracture of the distal end of radius represents the most common fracture of the upper extremity accounting for 16-20% of all fractures. Plating is now emerging as the gold standard for management of distal radius fractures due to increased rate of complications such as malunion, subluxation/dislocation of distal radio-ulnar joint or late collapse of fracture. Procedures such as closed reduction and cast immobilization, ligamentotaxis with external fixator and percutaneous pin fixation are no longer acceptable. Aim The purpose of the study was to evaluate the functional and radiological outcome of unstable distal radius fractures treated with the volar locking plate. Materials and Methods We reviewed 53 patients from January 2011 to December 2015, treated for unstable distal radius fractures using a volar locking compression plate. Standard radiographic and clinical assessment after 12 months (range 12-16 months) were measured and final functional and radiological outcome were assessed using the Modified Mayo wrist scoring system and Sarmiento’s modification of Lindstorm criteria respectively. Results There were 42 males and 11 females with an average age of 39.12±31.78 years (18-71 years). At the end of 12 months, 36 patients had an excellent radiological outcome and 10 patients had good radiological outcome as per Sarmiento’s modification of Lindstorm criteria. Eleven patients had an excellent functional outcome and 26 patients had a good functional outcome as per modified Mayo wrist scoring system. There was one case of superficial wound infection which subsided with intravenous antibiotics. Conclusion The volar locking plate fixation helps in early mobilization of the wrist, restores anatomy, allows early return to function, prevents secondary loss of reduction and hence is an effective treatment for unstable fractures of the distal radius. PMID:28274009

  11. Traumatic ulnar physeal arrest after distal forearm fractures in children.

    PubMed

    Ray, T D; Tessler, R H; Dell, P C

    1996-01-01

    A review of the orthopaedic literature suggests that traumatic ulnar physeal arrest associated with radial fracture is a rare occurrence. Twenty-three cases of traumatic ulnar physeal arrest have been reported in patients with distal radius fractures, and we report five additional cases. A classification system for the distal ulnar growth deformities is proposed, and the compensatory radial changes are reviewed. Surgical indications for treatment include cosmetic deformity, progressive carpal subluxation, and decreased range of motion. Surgical options for treatment are discussed and include epiphysiodesis, ulnar lengthening, radial osteotomy, and the Suave-Kapandji procedure.

  12. Nontraumatic osteonecrosis of the distal pole of the scaphoid

    PubMed Central

    Garg, Bhavuk; Gupta, Himanshu; Kotwal, Prakash P

    2011-01-01

    Post traumatic osteonecrosis of distal pole of scaphoid is very rare. We present a case of 34 years old male, drill operator by occupation with nontraumatic osteonecrosis of distal pole of the scaphoid. The patient was managed conservatively and was kept under regular follow-up every three months. The patient was also asked to change his profession. Two years later, the patient had no pain and had mild restriction of wrist movements (less than 15 degrees in either direction). The radiographs revealed normal density of the scaphoid suggesting revascularization. PMID:21430877

  13. Supramalleolar Osteotomies for Posttraumatic Malalignment of the Distal Tibia.

    PubMed

    Krause, Fabian; Veljkovic, Andrea; Schmid, Timo

    2016-03-01

    Supramalleolar osteotomies of the tibia (SMOT) for posttraumatic distal tibial malalignment has shown to reduce pain, improve function and radiographic signs of osteoarthritis, and delay ankle arthrodesis or total joint replacement. The procedure also protects the articular cartilage from further degenerative processes by shifting and redistributing loads in the ankle joint. It is technically demanding and requires extensive preoperative planning. The type of osteotomy (opening vs closing wedge) does not influence the final outcome. However, based on the limited evidence, a grade I treatment recommendation has been given for supramalleolar osteotomies of the tibia to treat mild to moderate ankle arthritis in the presence of distal tibial malalignment.

  14. A Unified Approach to Outcomes Assessment for Distal Radius Fractures.

    PubMed

    Waljee, Jennifer F; Ladd, Amy; MacDermid, Joy C; Rozental, Tamara D; Wolfe, Scott W

    2016-04-01

    Distal radius fractures are one of the most common upper extremity injuries. Currently, outcome assessment after treatment of these injuries varies widely with respect to the measures that are used, timing of assessment, and the end points that are considered. A more consistent approach to outcomes assessment would provide a standard by which to assess treatment options and best practices. In this summary, we review the consensus regarding outcomes assessment after distal radius fractures and propose a systematic approach that integrates performance, patient-reported outcomes, pain, complications, and radiographs.

  15. Future treatment and research directions in distal radius fracture.

    PubMed

    Jupiter, Jesse

    2012-05-01

    Whether or not they will have their lives dramatically extended in the next few decades, it is clear that people are living longer, healthier, and more active lives. The two peak incidences of distal radius fractures will remain within the pediatric and geriatric age groups, with the latter experiencing a substantial increase in the coming years. This article attempts to project future developments with regard to epidemiology, risk and prevention, fracture assessment, and treatment of distal radius fractures, and the ever increasing concern for the economic impact of this prevalent injury.

  16. Tool use and the distalization of the end-effector

    PubMed Central

    Bonaiuto, James B.; Jacobs, Stéphane; Frey, Scott H.

    2009-01-01

    We review recent neurophysiological data from macaques and humans suggesting that the use of tools extends the internal representation of the actor’s hand, and relate it to our modeling of the visual control of grasping. We introduce the idea that, in addition to extending the body schema to incorporate the tool, tool use involves distalization of the end-effector from hand to tool. Different tools extend the body schema in different ways, with a displaced visual target and a novel, task-specific processing of haptic feedback to the hand. This distalization is critical in order to exploit the unique functional capacities engendered by complex tools. PMID:19347356

  17. Optimal Positioning for Volar Plate Fixation of a Distal Radius Fracture: Determining the Distal Dorsal Cortical Distance.

    PubMed

    Vosbikian, Michael M; Ketonis, Constantinos; Huang, Ronald; Ilyas, Asif M

    2016-01-01

    Distal radius fractures are currently among the most common fractures of the musculoskeletal system. With a population that is living longer, being more active, and the increasing incidence of osteoporosis, these injuries will continue to become increasingly prevalent. When operative fixation is indicated, the volar locking plate has recently become the treatment of choice. However, despite its success, suboptimal position of the volar locking plate can still result in radiographic loss of reduction. The distal dorsal cortical distance is being introduced as an intraoperative radiographic tool to help optimize plate position and minimize late loss of fracture reduction.

  18. Divergent elbow dislocation with radial shaft fracture, distal ulnar deformation, and distal radioulnar joint instability: an unclassifiable Monteggia variant.

    PubMed

    Laratta, Joseph L; Yoon, Richard S; Frank, Matthew A; Koury, Kenneth; Donegan, Derek J; Liporace, Frank A

    2014-03-01

    Originally described by Monteggia and later classified by Bado, elbow dislocations with concurrent radial and ulnar shaft fractures with distal radioulnar joint (DRUJ) disruption are considered operative cases with high-energy injurious etiologies. Here, we present an unclassifiable Monteggia variant fracture suffered through a high axial load mechanism in a 47-year-old female. The fracture pattern initially exhibited included a divergent elbow dislocation, a radial shaft fracture, plastic deformation of the distal ulna, and DRUJ instability. Here we describe the pattern in detail, along with definitive treatment and clinical outcome at 1 year follow-up.

  19. Distal Prosodic Context Affects Word Segmentation and Lexical Processing

    ERIC Educational Resources Information Center

    Dilley, Laura C.; McAuley, J. Devin

    2008-01-01

    Three experiments investigated the role of distal (i.e., nonlocal) prosody in word segmentation and lexical processing. In Experiment 1, prosodic characteristics of the initial five syllables of eight-syllable sequences were manipulated; the final portions of these sequences were lexically ambiguous (e.g., "note bookworm", "notebook worm"). Distal…

  20. Fibrous Dysplasia in the Epiphysis of the Distal Femur

    PubMed Central

    Noh, Jung Ho; Lee, Jae Woo

    2017-01-01

    Fibrous dysplasia is a common benign skeletal lesion that may involve a single bone or multiple bones. Although fibrous dysplasia can affect any bone, monostotic fibrous dysplasia of the long bone typically occurs in the diaphysis or metaphysis. We report a very rare case of monostotic fibrous dysplasia involving the epiphysis of the distal femur in a young man. PMID:28231652

  1. Distal forearm fractures in children. Complications and surgical indications.

    PubMed

    Dicke, T E; Nunley, J A

    1993-04-01

    Appropriate indications for operative management of pediatric distal forearm fractures include: 1. Compartment syndrome for fasciotomy. 2. Open fractures for irrigation and debridement. 3. Soft tissue/nerve entrapment. 4. Displaced intra-articular physeal fractures. 5. Displaced or angulated fractures when the patient is close to skeletal maturity. 6. Correction of physeal arrest with malalignment or malrotation. 7. Gross displacement with cosmetic deformity.

  2. The effectiveness of distal soft tissue procedures in hallux valgus

    PubMed Central

    Ozturk, Hasan; Agus, Haluk; Altay, Taskin; Hancerli, Ozgur

    2008-01-01

    Background Hallux valgus is a common disorder affecting mostly women population. Distal soft tissue procedure in the treatment of hallux valgus is one of the main operative techniques described. The aim of this study is to evaluate the outcomes of McBride’s distal soft tissue procedure in hallux valgus cases. Materials and methods This study includes 30 patients (27 women) having 31 hallux valgus, who were treated between 1999 and 2004. Modified McBride’s distal soft tissue procedure was carried out in all cases. Pain status of the cases was recorded by using VAS, clinical assessment described by Bonney and Macnab, and American Orthopaedic Foot and Ankle Society’s (AOFAS) score at the last follow up. Results The mean hallux valgus and intermetatarsal angles decreased from 31.4° and 13.8° to 13.5° and 10.5°, respectively, with an average follow-up period of 54.4 months. AOFAS’s score displayed significant improvement from 57 to 87. The mean VAS showed a significant decrease from 8.75 preoperatively to 2.1 at the last follow-up. According to Bonney and Macnab criteria, only one case was accepted as poor result due to 5° hallux varus. Conclusions McBride’s distal soft tissue procedure yields high rate of satisfaction for mild to moderate hallux valgus with no bony complications related to osteotomy. PMID:19384606

  3. Familial distal trisomy 8(q24.13----qter).

    PubMed Central

    Romain, D R; Bloxham, R A; Columbano-Green, L M; Chapman, C J; Parfitt, R G; Smythe, R H; Cairney, H

    1989-01-01

    Trisomy for the distal part of the long arm of chromosome 8(q24.13----qter) is described in three sibs. The anomaly arose as an adjacent 1 meiotic segregation from a balanced reciprocal translocation t(1;8)(q44; q24.13)mat. Images PMID:2918543

  4. Corrective Osteotomy for Ipsilateral Distal Clavicular and Coracoid Malunions.

    PubMed

    Yoshida, Atsushi

    2015-08-01

    Malunion after double disruption injuries of the superior shoulder suspensory complex accompanied by shoulder pain and dysfunction has been reported infrequently. A 37-year-old man had a double disruption injury (fractures of the distal clavicle and the base of the coracoid process). Conservative treatment resulted in malunion. Twelve months after the injury, pain continued in the coracoclavicular interval, and there was only 125° forward shoulder elevation. Radiographs showed 50° inferior angulation of the distal clavicle and elongated base of the coracoid process. Corrective osteotomy was required; however, the concomitant malunion of the coracoid prevented correction of the deformity with osteotomy of the distal clavicle alone. Therefore, osteotomy of the coracoid was performed. Twelve months postoperatively, successful bone union resulted in loss of pain. Forward elevation had recovered to 160°. Distal clavicular fractures with concomitant coracoid fractures are often significantly displaced, which disrupts physiologic coupling of clavicular and scapular motion and limits forward elevation. In the case of such malunions, excessive movement at the clavicle-scapula junction during mobilization causes pain in the coracoclavicular interval. Correction of this deformity requires osteotomy of both the clavicular and coracoid malunions.

  5. Ultrasound-Guided Reduction of Distal Radius Fractures

    PubMed Central

    Sabzghabaei, Anita; Shojaee, Majid; Arhami Dolatabadi, Ali; Manouchehrifar, Mohammad; Asadi, Mahdi

    2016-01-01

    Introduction: Distal radius fractures are a common traumatic injury, particularly in the elderly population. In the present study we examined the effectiveness of ultrasound guidance in the reduction of distal radius fractures in adult patients presenting to emergency department (ED). Methods: In this prospective case control study, eligible patients were adults older than 18 years who presented to the ED with distal radius fractures. 130 consecutive patient consisted of two group of Sixty-Five patients were prospectively enrolled for around 1 years. The first group underwent ultrasound-guided reduction and the second (control group) underwent blind reduction. All procedures were performed by two trained emergency residents under supervision of senior emergency physicians. Results: Baseline characteristics between two groups were similar. The rate of repeat reduction was reduced in the ultrasound group (9.2% vs 24.6%; P = .019). The post reduction radiographic indices were similar between the two groups, although the ultrasound group had improved volar tilt (mean, 7.6° vs 3.7°; P = .000). The operative rate was reduced in the ultrasound groups (10.8% vs 27.7%; P = .014). Conclusion: Ultrasound guidance is effective and recommended for routine use in the reduction of distal radius fractures. PMID:27299141

  6. Non-reducible palmar dislocation of the distal radioulnar joint

    PubMed Central

    Zannou, Rupestre S.; Rezzouk, Joel; Ruijs, Aleid C.J.

    2015-01-01

    Abstract A rare case of an isolated traumatic palmar dislocation of the distal radioulnar joint is presented. Clinically, there is a loss of pronation and supination. The dislocation was treated using an open reduction, reinsertion of the capsule-ligamentous complex and temporary stabilization using K-wires. PMID:26158121

  7. Proximal versus Distal Validity Coefficients for Teacher Observational Instruments

    ERIC Educational Resources Information Center

    Marzano, Robert J.

    2014-01-01

    This study examined the use of measures of student learning computed using end-of-year assessments (distal measures) versus measures of student learning associated with a single lesson (proximal measures) as criterion scores for the validity of observations of teachers' pedagogical skills. The validity coefficients computed using distal…

  8. [Epiphyseal fractures of the distal tibia. Treatment and results].

    PubMed

    Wicky, B; Stauffer, U G

    1982-11-01

    Epiphyseal fractures of the distal end of the tibia generally require operative treatment. A conservative treatment can be recommended only in minimally displaced fractures with undisturbed ankle joint congruity. Among 48 patients treated (40 operatively, 8 conservatively) 6 developed angular deformities, 3 of which required a corrective osteotomy. After the initial treatment follow-up is necessary until bone growth is complete.

  9. Local repair of distal thoracal aortic dissections (Locus minoris resistencia).

    PubMed

    Belov, Iu V; Komarov, R N; Stepanenko, A B; Gens, A P; Charchian, E R

    2007-01-01

    The paper presents the method of local repair of distal aortic dissections. Local aortic grafting for surgical correction of type B dissecting aortic aneurysms helped to decrease hospital mortality up to 15.4%, the rate of paraparesis and multiorgan failure - up to 11.5%.

  10. Non-compliance Appliances for Upper Molar Distalization: An Overview.

    PubMed

    Noorollahian, Saeed; Alavi, Shiva; Shirban, Farinaz

    2015-01-01

    Tooth Size Arch-length Discrepancy (TSALD) is a common problem in orthodontics. Its clinical signs are tooth crowding, impaction and incisor proclination. The treatment options are dental arch expansion or tooth mass reduction (stripping or extraction). The "extraction versus non-extraction" controversy has been widely debated in the orthodontic literature. Distalization is a kind of arch expansion in anetro-posterior dimension. Several studies have evaluated both the therapeutic effectiveness and the side effects of the appliances for this method of space gaining. In some cases molar distalization is preferred, e.g., a patient with acceptable profile and skeletal pattern and half cusp Class II molar malocclusion or even less. In some cases molar distalization is the only way, e.g., the patient with previous upper premolar extraction and excessive overijet, or a skeletal Class III patient with previous upper premolar extraction needed upper anterior teeth retraction to create reverse overjet aspre surgical orthodontic decompensation. In this review article, we described non-compliance upper molar distalizing appliances.

  11. Haptic Distal Spatial Perception Mediated by Strings: Haptic "Looming"

    ERIC Educational Resources Information Center

    Cabe, Patrick A.

    2011-01-01

    Five experiments tested a haptic analog of optical looming, demonstrating string-mediated haptic distal spatial perception. Horizontally collinear hooks supported a weighted string held taut by a blindfolded participant's finger midway between the hooks. At the finger, the angle between string segments increased as the finger approached…

  12. Distal extension mandibular removable partial denture with implant support

    PubMed Central

    Bural, Canan; Buzbas, Begum; Ozatik, Sebnem; Bayraktar, Gulsen; Emes, Yusuf

    2016-01-01

    This case report describes the fabrication of a distal extension removable partial denture (RPD) of a 65-year-old man with implant support. Loss of fibroelasticity of the peripheral tissues and reduced mandibular vestibular sulcular depth due to a previous surgical resection and radiotherapy at the right side were the main clinical factors that created difficulty for denture retention and stability. The fabrication of a mandibular RPD supported by anterior teeth and two bilaterally placed implants in the molar area to convert from Kennedy Class 1 design to Kennedy Class 3 implant-bounded RPD is reported. Retention and stability of the denture were improved with implant support on the distal extension site of the RPD. The common clinical problems about distally extended RPDs are lack of retention and stability due to the movement around the rotational axis. Dental implant placement to the distal edentulous site minimizes the potential dislodgement of the RPD is popular. Implant-supported RPD can be suggested as an advantageous and cost-effective treatment option for the partially edentulous patients. PMID:28042277

  13. Prediction of distal residue participation in enzyme catalysis.

    PubMed

    Brodkin, Heather R; DeLateur, Nicholas A; Somarowthu, Srinivas; Mills, Caitlyn L; Novak, Walter R; Beuning, Penny J; Ringe, Dagmar; Ondrechen, Mary Jo

    2015-05-01

    A scoring method for the prediction of catalytically important residues in enzyme structures is presented and used to examine the participation of distal residues in enzyme catalysis. Scores are based on the Partial Order Optimum Likelihood (POOL) machine learning method, using computed electrostatic properties, surface geometric features, and information obtained from the phylogenetic tree as input features. Predictions of distal residue participation in catalysis are compared with experimental kinetics data from the literature on variants of the featured enzymes; some additional kinetics measurements are reported for variants of Pseudomonas putida nitrile hydratase (ppNH) and for Escherichia coli alkaline phosphatase (AP). The multilayer active sites of P. putida nitrile hydratase and of human phosphoglucose isomerase are predicted by the POOL log ZP scores, as is the single-layer active site of P. putida ketosteroid isomerase. The log ZP score cutoff utilized here results in over-prediction of distal residue involvement in E. coli alkaline phosphatase. While fewer experimental data points are available for P. putida mandelate racemase and for human carbonic anhydrase II, the POOL log ZP scores properly predict the previously reported participation of distal residues.

  14. Intrafocal pinning for distal radius metaphyseal fractures in children.

    PubMed

    Parikh, Shital N; Jain, Viral V; Youngquist, Jeffrey

    2013-06-01

    The purpose of this retrospective case control study was to evaluate the results of intrafocal pinning for distal radius metaphyseal fractures in children and to compare these results with conventional pinning. Data were collected from medical records and radiographs from patients who underwent closed reduction and percutaneous pinning for distal radius fracture in a Level I trauma center at the authors' institution between 2008 and 2010. Inclusion criteria included a dorsally angulated metaphyseal fracture without physeal involvement, an open distal radius physis, and a follow-up to radiographic union. A total of 10 patients with intrafocal pinning were compared to 26 patients with conventional pinning. Preoperatively, angulation was greater in patients who received intrafocal pinning than conventional pinning based on anteroposterior radiographs. Postoperatively, the 2 groups did not differ in angulation on either anteroposterior or lateral radiographs. One malunion and 2 pin-related complications occurred in the conventional pinning group, and 1 pin-related complication occurred in the intrafocal pinning group. The 2 groups did not differ by age, sex, side of injury, days to surgery, or initial shortening. This study affirms that the intrafocal pinning technique is an alternative to the conventional pinning technique for the stabilization of displaced metaphyseal distal radius fractures in children. Intrafocal pinning can also be used as a reduction tool for fractures that cannot be reduced by closed manipulation. The complications are comparable between the 2 techniques.

  15. Simultaneous bilateral distal biceps tendon repair: case report.

    PubMed

    Storti, Thiago Medeiros; Paniago, Alexandre Firmino; Faria, Rafael Salomon Silva

    2017-01-01

    Simultaneous bilateral rupture of the distal biceps tendon is a rare clinical entity, seldom reported in the literature and with unclear therapeutic setting. The authors report the case of a 39-year-old white man who suffered a simultaneous bilateral rupture while working out. When weightlifting with elbows at 90° of flexion, he suddenly felt pain on the anterior aspect of the arms, coming for evaluation after two days. He presented bulging contour of the biceps muscle belly and ecchymosis in the antecubital fossa, extending distally to the medial aspect of the forearm, as well as a marked decrease of supination strength and pain in active elbow flexion. MRI confirmed the rupture with retraction of the distal biceps bilaterally. The authors opted for performing the tendon repairs simultaneously through the double incision technique and fixation to the bicipital tuberosity with anchors. The patient progressed quite well, with full return to labor and sports activities, being satisfied with the result after two years of surgery. In the literature search, few reports of simultaneous bilateral rupture of the distal biceps were retrieved, with only one treated in the acute phase of injury. Therefore, the authors consider this procedure to be a good option to solve this complex condition.

  16. Predicting the failure load of the distal radius.

    PubMed

    Muller, Monique E; Webber, Colin E; Bouxsein, Mary L

    2003-06-01

    The distal radius is an important site for the early detection of patients at risk for fracture. Since measuring bone strength in vivo is not possible, we evaluated which bone assessment method of the forearm would best predict failure load of the distal radius and computed a factor of risk for wrist fracture (Phi wrist). Thirty-eight cadaveric forearm specimens were measured by five different techniques to assess bone density, bone mineral content, geometry and trabecular structure at the distal forearm. The bone assessment techniques included dual-energy X-ray absorptiometry (DXA) of the radius, peripheral quantitative computed tomography (pQCT) of the 4% and 20% distal sites of the radius, DXA of the phalanges, digital X-ray radiogrammetry of the forearm (DXR-BMD), and quantitative ultrasound of the radius. The failure load of each excised radius was determined by simulating a fall on an outstretched hand. The pQCT measurements of polar stress-strain index and cortical content explained the greatest portion of variance in failure load (r2=0.82-0.85). Bone mineral content measures were generally better predictors of failure load (r2=0.53-0.85) than the corresponding volumetric or areal bone mineral density values (r2=0.22-0.69) measured by either pQCT or DXA. Multiple regression analysis showed that the addition of a bone geometry measure improved the ability of a bone density measure alone to predict failure load. There was high variability in the ability of different techniques and different variables within a given technique to predict failure load. Estimates of the factor of risk for wrist fracture (Phi wrist) revealed that the women in this study would have been likely to fracture their distal radius upon falling from a standing height (Phi wrist= 1.04), whereas the men would have likely withstood the impact without fracturing their wrist (Phi wrist= 0.79).

  17. Regulation of the epithelial Na+ channel by the mTORC2/SGK1 pathway.

    PubMed

    Lang, Florian; Pearce, David

    2016-02-01

    The epithelial Na(+) channel (ENaC) is decisive for sodium reabsorption by the aldosterone-sensitive distal nephron (ASDN) of the kidney. ENaC is regulated by the serum- and glucocorticoid-inducible kinase 1 (SGK1), a kinase genomically upregulated by several hormones including glucocorticoids and mineralocorticoids. SGK1 is activated by the serine/threonine kinase mammalian target of rapamycin (mTOR) isoform mTORC2. SGK1 knockout (sgk1(-/-) mice) impairs renal Na(+) retention during salt depletion. The mTOR catalytic site inhibitor, PP242, but not mTORC1 inhibitor rapamycin, inhibits ENaC, decreases Na(+) flux in isolated perfused tubules and induces natriuresis in wild-type mice. PP242 does not lead to further impairment of Na(+) reabsorption in sgk1(-/-) mice. The mTORC2/SGK1 sensitive renal Na(+) retention leads to extracellular volume expansion with increase of blood pressure. A SGK1 gene variant (prevalence ∼ 3-5% in Caucasians, ∼ 10% in Africans) predisposes to hypertension, stroke, obesity and type 2 diabetes. Future studies will be required to define the role of mTORC2 in the regulation of further SGK1 sensitive transport proteins, such as further ion channels, carriers and the Na(+)/K(+)-ATPase. Moreover, studies are required disclosing the impact of mTORC2 on SGK1 sensitive disorders, such as hypertension, obesity, diabetes, thrombosis, stroke, inflammation, autoimmune disease, fibrosis and tumour growth.

  18. Norepinephrine stimulates the epithelial Na+ channel in cortical collecting duct cells via α2-adrenoceptors.

    PubMed

    Mansley, Morag K; Neuhuber, Winfried; Korbmacher, Christoph; Bertog, Marko

    2015-03-01

    There is good evidence for a causal link between excessive sympathetic drive to the kidney and hypertension. We hypothesized that sympathetic regulation of tubular Na(+) absorption may occur in the aldosterone-sensitive distal nephron, where the fine tuning of renal Na(+) excretion takes place. Here, the appropriate regulation of transepithelial Na(+) transport, mediated by the amiloride-sensitive epithelial Na(+) channel (ENaC), is critical for blood pressure control. To explore a possible effect of the sympathetic transmitter norepinephrine on ENaC-mediated Na(+) transport, we performed short-circuit current (Isc) measurements on confluent mCCDcl1 murine cortical collecting duct cells. Norepinephrine caused a complex Isc response with a sustained increase of amiloride-sensitive Isc by ∼44%. This effect was concentration dependent and mediated via basolateral α2-adrenoceptors. In cells pretreated with aldosterone, the stimulatory effect of norepinephrine was reduced. Finally, we demonstrated that noradrenergic nerve fibers are present in close proximity to ENaC-expressing cells in murine kidney slices. We conclude that the sustained stimulatory effect of locally elevated norepinephrine on ENaC-mediated Na(+) absorption may contribute to the hypertensive effect of increased renal sympathetic activity.

  19. Purinergic inhibition of ENaC produces aldosterone escape.

    PubMed

    Stockand, James D; Mironova, Elena; Bugaj, Vladislav; Rieg, Timo; Insel, Paul A; Vallon, Volker; Peti-Peterdi, Janos; Pochynyuk, Oleh

    2010-11-01

    The mechanisms underlying "aldosterone escape," which refers to the excretion of sodium (Na(+)) during high Na(+) intake despite inappropriately increased levels of mineralocorticoids, are incompletely understood. Because local purinergic tone in the aldosterone-sensitive distal nephron downregulates epithelial Na(+) channel (ENaC) activity, we tested whether this mechanism mediates aldosterone escape. Here, urinary ATP concentration increased with dietary Na(+) intake in mice. Physiologic concentrations of ATP decreased ENaC activity in a dosage-dependent manner. P2Y(2)(-/-) mice, which lack the purinergic receptor, had significantly less increased Na(+) excretion than wild-type mice in response to high-Na(+) intake. Exogenous deoxycorticosterone acetate and deletion of the P2Y(2) receptor each modestly increased the resistance of ENaC to changes in Na(+) intake; together, they markedly increased resistance. Under the latter condition, ENaC could not respond to changes in Na(+) intake. In contrast, as a result of aldosterone escape, wild-type mice had increased Na(+) excretion in response to high-Na(+) intake regardless of the presence of high deoxycorticosterone acetate. These data suggest that control of ENaC by purinergic signaling is necessary for aldosterone escape.

  20. Purinergic Inhibition of ENaC Produces Aldosterone Escape

    PubMed Central

    Mironova, Elena; Bugaj, Vladislav; Rieg, Timo; Insel, Paul A.; Vallon, Volker; Peti-Peterdi, Janos

    2010-01-01

    The mechanisms underlying “aldosterone escape,” which refers to the excretion of sodium (Na+) during high Na+ intake despite inappropriately increased levels of mineralocorticoids, are incompletely understood. Because local purinergic tone in the aldosterone-sensitive distal nephron downregulates epithelial Na+ channel (ENaC) activity, we tested whether this mechanism mediates aldosterone escape. Here, urinary ATP concentration increased with dietary Na+ intake in mice. Physiologic concentrations of ATP decreased ENaC activity in a dosage-dependent manner. P2Y2−/− mice, which lack the purinergic receptor, had significantly less increased Na+ excretion than wild-type mice in response to high-Na+ intake. Exogenous deoxycorticosterone acetate and deletion of the P2Y2 receptor each modestly increased the resistance of ENaC to changes in Na+ intake; together, they markedly increased resistance. Under the latter condition, ENaC could not respond to changes in Na+ intake. In contrast, as a result of aldosterone escape, wild-type mice had increased Na+ excretion in response to high-Na+ intake regardless of the presence of high deoxycorticosterone acetate. These data suggest that control of ENaC by purinergic signaling is necessary for aldosterone escape. PMID:20813869

  1. Rapid palatal expander: an anchor unit for second molar distalization in Angle Class II treatment.

    PubMed

    Kolokitha, Olga-Elpis; Papadopoulou, Alexandra K

    2010-01-01

    Distal movement of maxillary molars is a common approach for nonextraction treatment of Angle Class II patients. Because of known difficulties involving moving the maxillary first molars distally in the presence of second molars, this article describes how the distally directed force is applied immediately to the second molars. A rapid palatal expander can be used as a reliable unit to facilitate the distal movement of the second maxillary molars.

  2. Distal thoracic oesophageal perforation secondary to blunt trauma: Case report

    PubMed Central

    Strauss, Dirk C; Tandon, Ruchi; Mason, Robert C

    2007-01-01

    Background Traumatic perforation of the distal oesophagus due to blunt trauma is a very rare condition and is still associated with a significant morbidity and mortality. This is further exacerbated by delayed diagnosis and management as symptoms and signs are often masked by or ascribed to more common blunt thoracic injuries. Case report We present a case of a distal oesophageal perforation, secondary to a fall from a third storey window, which was masked by concomitant thoracic injuries and missed on both computed tomography imaging and laparotomy. The delay in his diagnosis significantly worsened the patient's recovery by allowing the development of an overwhelming chest sepsis that contributed to his death. Conclusion Early identification of an intrathoracic oesophageal perforation requires deliberate consideration and is essential to ensure a favorable outcome. Treatment should be individualised taking into account the nature of the oesophageal defect, time elapsed from injury and the patient's general condition. PMID:17374175

  3. Osteomyelitis Caused by Candida glabrata in the Distal Phalanx

    PubMed Central

    Hibino, Naohito; Sairyo, Koichi; Yoshioka, Shinji; Yamano, Masahiro; Henmi, Tatsuhiko

    2014-01-01

    Osteomyelitis caused by Candida glabrata is rare and its optimal treatment is unknown. Here we report a case of osteomyelitis caused by C. glabrata in the distal phalanx in a 54-year-old woman. Despite partial resection of the nail and administering a 1-month course of antibiotics for paronychia, the local swelling remained and an osteolytic lesion was found. C. glabrata osteomyelitis of the distal phalanx was later diagnosed after curettage. Thereafter, the patient was treated with antifungal agents for 3 months. The infection eventually resolved, and radiological healing of the osteolytic lesion was achieved. Antifungal susceptibility testing should be performed in the case of osteomyelitis caused by nonalbicans Candida species, due to their resistance to fluconazole. PMID:25215255

  4. Single absorbable polydioxanone pin fixation for distal chevron bunion osteotomies.

    PubMed

    Deorio, J K; Ware, A W

    2001-10-01

    The distal chevron osteotomy is a well-established technique for correction of symptomatic mild to moderate metatarsus primus varus with hallux valgus deformity. Fixation of the osteotomy ranges from none to bone pegs, Kirschner wires, screws, or absorbable pins. We evaluated one surgeon's (J.K.D.) results of distal chevron osteotomy fixation with a single, nonpredrilled, 1.3-mm poly-p-dioxanone pin and analyzed any differences in patients with unilateral or bilateral symptomatic metatarsus primus varus with hallux valgus deformities. All osteotomies healed without evidence of infection, osteolysis, nonunion, or necrosis. Equal correction was achieved in unilateral and bilateral procedures. The technique is quick and easy, and adequate fixation is achieved.

  5. [Therapy principles of distal fractures of the forearm in childhood].

    PubMed

    Laurer, H; Sander, A; Wutzler, S; Walcher, F; Marzi, I

    2009-11-01

    Fractures of the forearm in children represent one of the most frequent injuries. Most are monotraumatic occurring during sport or leisure activities. Diagnosis can be made by conventional X-ray examination in 2 planes. Distal forearm fractures are classified into epiphyseolysis and epiphyseal fractures, metaphyseal greenstick and buckle fractures, complete distal radius and forearm fractures as well as Galeazzi lesions. The vast majority of cases without relevant dislocation can be treated with immobilization employing a cast. The remaining fractures have to be repositioned and restored depending on age and degree of dislocation.The state of the art in surgical therapy is the Kirschner wire osteosynthesis after closed reduction. Especially meta-diaphyseal fractures can alternatively be stabilized with plate osteosynthesis or external fixation. Following these therapeutic principles, prognosis is excellent and most of the injuries heal without any functional impairment.

  6. Preventing pancreatic fistula after distal pancreatectomy: An invagination method

    PubMed Central

    Katsura, Nagato; Kawai, Yasuhiro; Gomi, Takashi; Okumura, Kenji; Hoashi, Takahiko; Fukuda, Seijun; Takebayashi, Katsushi; Shimizu, Kenji; Satoh, Masugi

    2017-01-01

    Following an increase in the use of the GIA stapler for treating a pancreatic stump, more techniques to prevent postoperative pancreatic juice leakage have been required. We describe one successful case using our new technique of invaginating the cut end of the pancreas into the stomach to prevent a pancreatic fistula (PF) from occurring. A 50-year-old woman with pancreatic cancer in the tail of the pancreas underwent distal pancreatectomy, causing a grade A PF. We resected the distal pancreas without additional reinforcement to invaginate the stump into the gastric posterior wall with single layer anastomosis using a 3-0 absorbable suture. The drain tubes were removed on the third postoperative day. Although a grade A PF was noted, the patient was discharged on foot on the eleventh postoperative day. Our technique may be a suitable method for patients with a pancreatic body and tail tumor. PMID:28293098

  7. A New Distal Arthrogryposis Syndrome Characterized by Plantar Flexion Contractures

    PubMed Central

    Stevenson, D.A.; Swoboda, K.J.; Sanders, R.K.; Bamshad, M.

    2011-01-01

    The distal arthrogryposis (DA) syndromes are a distinct group of disorders characterized by contractures of two or more different body areas. More than a decade ago, we revised the classification of DAs and distinguished several new syndromes. This revision has facilitated the identification of five genes (i.e., TNNI2, TNNT3, MYH3, MYH8, and TPM2) that encode components of the contractile apparatus of fast-twitch myofibers and cause DA syndromes. We now report the phenotypic features of a novel DA disorder characterized primarily by plantar flexion contractures in a large five-generation Utah family. Contractures of hips, elbows, wrists, and fingers were much milder though they varied in severity among affected individuals. All affected individuals had normal neurological examinations; electromyography and creatinine kinase levels were normal on selected individuals. We have tentatively labeled this condition distal arthrogryposis type 10 (DA10). PMID:17103435

  8. [Distal radius fractures: new concepts as basis for surgical treatment].

    PubMed

    Rikli, D A; Babst, R; Jupiter, J B

    2007-02-01

    New advances in the biomechanics and pathomechanics of distal radius fractures as well as new generations of plates and improved surgical approaches now make possible the stable management and early functional rehabilitation not only of simple but also of complicated distal radius fractures according to the principles for articular and juxta-articular fractures. Especially for complex articular fractures, the fracture patterns are so heterogeneous that an individual surgical treatment strategy must be developed for each case. The preoperative clarification of articular fractures with computed tomography is particularly useful for planning surgery. Mental exposition with the three-column model and pathomechanics is an important prerequisite for understanding this type of injury and the appropriate choice of operative technique. A decisive factor for success is the subtle surgical procedure in approaching and handling the fine plates.

  9. Role of distal reabsorption and peritubular environment in glomerulotubular balance.

    NASA Technical Reports Server (NTRS)

    Schrier, R. W.; Humphreys, M. H.

    1972-01-01

    Total kidney glomerulotubular balance was examined during aortic constriction and release in saline-loaded dogs and in dogs undergoing water diuresis. Aortic constriction lowered the glomerular filtration rate by 45% in both groups, and glomerulotubular balance, as judged by changes in absolute sodium reabsorption, was also comparable. During water diuresis, a linear relationship was observed between free water clearance and urine flow during all maneuvers, suggesting that distal sodium reabsorption is related primarily to distal delivery. The results suggest that if alterations in the peritubular environment are responsible for the changes in tubular sodium reabsorption during aortic constriction in the saline- or water-loaded dog, then a change in renal plasma flow, and presumably delivery rate of oncotic force, may be the most likely mediator.

  10. Pendulum Therapy of Molar Distalization in Mixed Dentition

    PubMed Central

    Prakash, Amit; Agarwal, Anshu

    2016-01-01

    ABSTRACT Early and timely pedo-orthodontic treatment is aimed at eliminating the disturbances of skeletal or dentoalveolar development, to harmonize the stomatognathic system before the full eruption of all permanent teeth. The advantages of pendulum appliance are its minimal dependence on patient’s compliance (child cooperation), ease of fabrication, onetime activation and adjustment of the springs if necessary to correct minor transverse and vertical molar positions. This article reports a successful treatment method of class II malocclusion with pendulum appliance in mixed dentition phase. Distalization of maxillary molar was done, followed by guidance of canine impaction orthodontically and other dental correction using 0.022 MBT appliances. Posttreatment results were stable and remarkable. How to cite this article: Patil RU, Prakash A, Agarwal A. Pendulum Therapy of Molar Distalization in Mixed Dentition. Int J Clin Pediatr Dent 2016;9(1):67-73. PMID:27274159

  11. Pendulum Therapy of Molar Distalization in Mixed Dentition.

    PubMed

    Patil, Raju Umaji; Prakash, Amit; Agarwal, Anshu

    2016-01-01

    Early and timely pedo-orthodontic treatment is aimed at eliminating the disturbances of skeletal or dentoalveolar development, to harmonize the stomatognathic system before the full eruption of all permanent teeth. The advantages of pendulum appliance are its minimal dependence on patient's compliance (child cooperation), ease of fabrication, onetime activation and adjustment of the springs if necessary to correct minor transverse and vertical molar positions. This article reports a successful treatment method of class II malocclusion with pendulum appliance in mixed dentition phase. Distalization of maxillary molar was done, followed by guidance of canine impaction orthodontically and other dental correction using 0.022 MBT appliances. Posttreatment results were stable and remarkable. How to cite this article: Patil RU, Prakash A, Agarwal A. Pendulum Therapy of Molar Distalization in Mixed Dentition. Int J Clin Pediatr Dent 2016;9(1):67-73.

  12. Distally Based Abductor Hallucis Adipomuscular Flap for Forefoot Plantar Reconstruction.

    PubMed

    Lee, Sanglim; Kim, Min Bom; Lee, Young Ho; Baek, Jeong Kook; Baek, Goo Hyun

    2015-09-01

    Soft tissue and bone defects of the lower leg, ankle, and heel region often require coverage by local or distant flaps. The authors successfully used the distally based adipomuscular abductor hallucis flap for the treatment of 7 patients with soft tissue defect on the plantar forefoot after diabetic ulcer (n = 2), excision of melanoma at the medial forefoot (n = 3), and posttraumatic defects of the plantar forefoot (n = 2). The size of the defects ranged from 6 to 36 cm. All defects were covered successfully without major complications. The distally based adipomuscular flap from the abductor hallucis muscle provides a reliable coverage for small and moderate defects of the plantar and medial forefoot. This flap is often preferable to the use of free flaps because the surgery is rapidly performed and does not require microsurgical expertise.

  13. Biomechanics and biology of plate fixation of distal radius fractures.

    PubMed

    Freeland, Alan E; Luber, Kurre T

    2005-08-01

    The fracture management principles of anatomic or near anatomic reduction, fracture stabilization, minimal operative trauma, and early joint motion are paramount in man-aging unstable distal radial fractures. The operative approach and plate selection should correlate with the fracture configuration. Plates have the advantages of providing secure fixation throughout the entire healing process without protruding wires or pins and allowing early and intensive forearm, wrist, and digital exercises. Disadvantages include additional operative trauma, including fragment devascularization; some additional risk of wrist stiffness; occasional tendon rupture; and at times, the need for plate removal. New developments in plate and screw design and operative strategies, fragment specific fixation, and plate strength have improved results with plate fixation. Fixed angle blades and locking screws and pegs enhance overall plate stability, support the articular surface of the distal radius, and are effective in fractures occurring in osteopenic bone.

  14. Implications and Cost of Pancreatic Leak Following Distal Pancreatic Resection

    PubMed Central

    Rodríguez, J. Rubén; Germes, Santos Soto; Pandharipande, Pari V.; Gazelle, G. Scott; Thayer, Sarah P.; Warshaw, Andrew L.; Fernández-del Castillo, Carlos

    2014-01-01

    Objectives Pancreatic stump leak (PL) after elective distal pancreatic resection significantly impacts cost and increases subsequent health care resource utilization. We sought to provide an economic framework for potential interventions aimed at reducing its occurrence. Design Retrospective case series and economic evaluation. Setting University-affiliated, tertiary care referral center. Patients Sixty-six patients undergoing elective distal, pancreatectomy. Main Outcome Measures Postoperative complications; hospital and professional costs. Results Overall postoperative morbidity occurred in 34 patients (52%) with no deaths. The total number of patients with complications directly related to PL was 22 (33%). The mean ± SD number of total hospital days for the no-PL group was 5.2 ± 1.7 days (range, 3–12 days) vs 16.6 ± 14.6 days (range, 4–49 days) for the PL group (P = .001). The average patient with PL-related problems incurred a total cost that was 2.01 times greater than the average patient in the no-PL group. A decision analytic model developed to evaluate threshold costs showed that a hypothetical intervention designed to reduce the complication rate of distal pancreatectomy by one third would be financially justifiable up to a cost of $1418 per patient. Conclusions Complications derived from PL following distal pancreatectomy double the cost and dramatically increase health care resource utilization. There is an urgent need to develop strategies that reduce the incidence of this common complication. Interventions aimed at decreasing the incidence of PL should take into account this cost differential. We provide an economic model to serve as a guide for developing these technologies. PMID:16618893

  15. Medical management of fragility fractures of the distal radius.

    PubMed

    Morgan, Emily N; Crawford, David A; Scully, William F; Noce, Nicholas J

    2014-12-01

    Fragility fractures of the distal radius represent an opportunity to diagnose and treat osteoporosis before further fractures occur. The goal of this study was to determine the prevalence of prescriptions for calcium/vitamin D supplementation and the prevalence of dual-energy x-ray absorptiometry (DEXA) scans in patients who sustained fragility fractures of the distal radius. A further goal was to determine the prevalence of patients who received prescriptions for the treatment of osteoporosis after DEXA scans. The authors performed a retrospective review of all patients 50 years and older who sustained a fragility fracture of the distal radius and were treated by the orthopedic surgery service at the authors' institution from 2004 to 2010. After a fragility fracture of the distal radius, fewer than 25% of previously unidentified at-risk patients received a prescription for vitamin supplementation and underwent a DEXA scan. Women were 7 times more likely than men to receive calcium/vitamin D supplementation, 14 times more likely to undergo a DEXA scan for the evaluation of osteoporosis, and 25 times more likely to receive a prescription for bisphosphonates. Patients who underwent a DEXA scan were 9 times more likely to receive pharmacologic treatment than those who did not undergo this scan. More than half of patients did not receive a prescription for calcium/vitamin D supplementation and did not undergo DEXA scanning as recommended by current National Osteoporosis Foundation guidelines. Most patients who received prescriptions or underwent DEXA scans did so before rather than after fracture, indicating poor compliance with National Osteoporosis Foundation guidelines.

  16. Sibs lacking characteristic features of duplication of distal 17q.

    PubMed Central

    Ohdo, S; Madokoro, H; Sonoda, T; Ohba, K

    1989-01-01

    Two brothers with karyotype 46,XY,-16,+der(16),t(16;17)(q24.3;q25.1)pat are presented. It is commonly thought that duplication of distal 17q results in a clinically recognisable syndrome. Although our cases had several features often seen in patients with autosomal chromosome aberrations, they did not have any of the specific features found in other patients with this duplication. Images PMID:2664178

  17. Physical and Comparative Mapping of Distal Mouse Chromosome 16

    PubMed Central

    Cabin, Deborah E.; McKee-Johnson, Jennifer W.; Matesic, Lydia E.; Wiltshire, Tim; Rue, Elizabeth E.; Mjaatvedt, Anne E.; Huo, Yong Kang; Korenberg, Julie R.; Reeves, Roger H.

    1998-01-01

    Distal mouse Chromosome 16 (Chr. 16) includes a region of conserved linkage with human Chromosome 21 (Chr. 21). Mouse models of Down syndrome based on trisomy of distal Chr. 16 have several phenotypes similar to those seen in human patients and have proven useful for correlating dosage imbalance of specific genes with specific developmental anomalies. The degree to which such findings can be related to Down syndrome depends on how well the conserved synteny is maintained. Twenty-four genes have been mapped in both species and there are no discordancies, but the region could carry hundreds of genes. Comparative sequence represents the ultimate comparative map and will aid in identification of genes and their regulatory sequences. A physical map of the distal 4.5 Mb of Chr. 16 has been assembled as an essential step toward a map of sequence-ready templates. The map consists of 51 YACs and 15 BACs and includes 18 transcripts, 9 of which are mapped for the first time in mouse, and 3 of which are, for the first time, described in either species. YAC fragmentation was used to precisely localize the 49 markers on the map. Comparison of this physical map with that of the corresponding region on Chr. 21 shows conservation not only of gene order but of size in the 3 Mb from Cbr1 to Ets2; distal to Ets2, the human map is expanded. [The sequence data described in this paper have been submitted to GenBank. See Tables 1 and 2 for accession nos.] PMID:9750193

  18. Defining the distal margin of rectal cancer for surgical planning

    PubMed Central

    Kato, Takashi; Tanaka, Jun-Ichi

    2017-01-01

    Accurate measurement of the distal rectal tumor margin is essential in selecting the appropriate surgical procedure. However, there is no standard measurement method. The National Cancer Institute consensus group recommends use of the anal verge (AV) as a landmark, and the European Society of Gastrointestinal and Abdominal Radiology recommends use of the anorectal ring (ARR). In addition, whether measurements should be made on double contrast barium enema (BE) radiographs or magnetic resonance (MR) images remains controversial. We measured the distal tumor margin on both BE and MR images obtained preoperatively from 52 patients who underwent sphincter-saving resection for rectal cancer. The distances from the distal end of the tumor to the AV and the ARR were measured on both types of images, and the variability was investigated by Bland-Altman analysis. The mean distance from the tumor to the AV was 8.9 cm on the BE radiographs and 7.7 cm on the MR images (P=0.013). The mean distances to the ARR were 6.8 and 5.6 cm, respectively (P=0.070). Significant proportional bias was shown as the measured distances increased, the difference between the BE- and magnetic resonance imaging (MRI)-based measurements increased. Use of one or the other landmark did not affect selection of the appropriate surgical procedure. We conclude that an approximate 1-cm underestimation should be taken into account when MRI-based measurement of the distal rectal tumor margin is used to choose between sphincter-saving resection and abdominoperineal resection. PMID:28280625

  19. Dorsal Capsuloplasty for Dorsal Instability of the Distal Ulna

    PubMed Central

    Kouwenhoven, S.T.P.; de Jong, T.; Koch, A.R.

    2013-01-01

    Background Dorsal instability of the distal ulna can lead to chronic wrist pain and loss of function. Structural changes to the dorsal radioulnar ligaments (DRUL) of the triangular fibrocartilage complex (TFCC) and the dorsal capsule around the ulnar head with or without foveal detachment can lead to volar subluxation of the distal radius e.g., dorsal instability of the distal ulna. Purpose Is to evaluate the post-operative results of reinstituting distal radioulnar joint (DRUJ) stability through reefing of the dorsal capsule and dorsal radioulnar ligaments, with and without a foveal reattachment of the TFCC. Methods A total of 37 patients were included in this retrospective study. Diagnosis and treatment was based strictly on dry wrist arthroscopy. In 17 patients isolated reefing of the DRUL and their collateral tissue extension was performed. In 20 patients an additional foveal reinsertion was performed. Postoperative results were evaluated with the DASH questionnaire, VAS scores, grip strength and range of motion. These findings were extrapolated in the Mayo wrist score. The two subgroups were compared. Results Mayo wrist scores of the whole population had a mean of 73. There was no difference between the group that was treated with reefing of the DRUL only and the group that was treated with a combined foveal reinsertion. Conclusion This relatively simple 'dorsal reefing' procedure, with foveal reinsertion when indicated, is a reliable method to restore volar-dorsal DRUJ stability with a significant decrease in pain sensation, good DASH scores and restoration of functional grip strength and ROM. Type of Study/Level of Evidence Therapeutic, Level IV. PMID:24436811

  20. FUNCTIONAL OUTCOMES AFTER DISTAL BICEPS BRACHII REPAIR: A CASE SERIES

    PubMed Central

    Morris, Tim; Otto, Charissa; Zerella, Tanisha; Semmler, John G; Human, Taaibos; Phadnis, Joideep; Bain, Gregory I

    2016-01-01

    Objectives To investigate outcomes after surgical repair of distal biceps tendon rupture and the influence of arm dominance on isokinetic flexion and supination results. Background/Purpose While relatively uncommon, rupture of the distal biceps tendon can result in significant strength deficits, for which surgical repair is recommended. The purpose of this study was to assess patient reported functional outcomes and muscle performance following surgery. Methods A sample of 23 participants (22 males, 1 female), who had previously undergone surgical repair of the distal biceps tendon, were re-examined at a minimum of one year after surgery. Biodex isokinetic elbow flexion and supination testing was performed to assess strength (as measured by peak torque) and endurance (as measured by total work and work fatigue). The Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) and Mayo Elbow Performance Scale (MEPS) were used to assess participants' subjectively reported functional recovery. Results At a mean of 7.6 years after surgical repair, there were no differences between the repaired and uninvolved elbows in peak torque (p = 0.47) or total work (p = 0.60) for flexion or supination. There was also no difference in elbow flexion work fatigue (p = 0.22). However, there was significantly less work fatigue in supination, which was likely influenced by arm dominance, as most repairs were to the dominant arm, F(1,22)=5.67, p = 0.03. Conclusion The long-term strength of the repaired elbow was similar to the uninvolved elbow after surgery to the distal biceps tendon. Endurance of the repaired elbow was similar in flexion but greater in supination, probably influenced by arm dominance. Study design Retrospective case series Level of Evidence Level 4 PMID:27904798

  1. [Distal tibia peri-implant fracture with an intramedullary nail: a case report].

    PubMed

    Reyes-Cabrera, J M; González-Alconada, R; García-Mota, M D

    2013-01-01

    Peri-implant fractures of the distal tibia after intramedullary nailing are rare. We present a case of a fracture of the distal tibia at the site of the distal interlocking screw. We found two cases reported in the world literature. There are no cases reported in the Spanish literature.

  2. Post-traumatic osteonecrosis of the lunate after fracture of the distal radius.

    PubMed

    Nakanishi, Akito; Yajima, Hiroshi; Kisanuki, Osamu

    2014-12-01

    We present a case of post-traumatic osteonecrosis of the lunate after fracture of the distal radius. Post-traumatic osteonecrosis of the carpal lunate after a fracture of the distal radius has, to our knowledge, not been reported previously. We treated the patient with vascularised bone graft from the distal radius, with a satisfactory result.

  3. Slipped Distal Femoral Epiphysis in Congenital Insensitivity to Pain

    PubMed Central

    Shaikh, M Javed; Rex, C; Vignesh, R; Chavan, Madhav

    2016-01-01

    Introduction: Congenital insensitivity to pain (CIP) is a rare disorder, and often presents to an orthopaedic surgeon as recurrent fractures, dislocations, pseudoarthrosis, osteomyelitis etc. Here, we report a case of congenital insensitivity to pain presenting with distal femoral physeal separation in a child. Case Report: A 12-year-old girl child came with complaints of limp while walking and swelling in the left knee for past 5 weeks. Mother gave a history that the girl is a known case of congenital insensitivity to pain with clear history of no pain on intramuscular injection since birth. She was born of consanguineous marriage and had no significant trauma, fever, other joint involvement or any features of rheumatism. On local examination, she had no bony tenderness, mild warmth, and moderate knee effusion with restricted range of movement. Plain radiograph showed epiphysiolysis of distal femur with widening of physis. Examination under anaesthesia demonstrated gross movement indicating lower femoral physeal separation. This unstable distal femoral epiphysis was treated under general anaesthesia with closed reduction, percutaneous cross pinning and above knee plaster cast. Conclusion: Congenital insensitivity to pain (CIP) is a rare disorder to diagnose. Emphasis is given on early diagnosis of orthopaedic problems and prompt treatment, educating parents and prevention of accidents. Physeal separation without significant trauma must prompt an orthopaedic surgeon to think about congenital insensitivity to pain as a differential diagnosis. PMID:27703943

  4. Complications of pediatric distal radius and forearm fractures.

    PubMed

    Chia, Benjamin; Kozin, Scott H; Herman, Martin J; Safier, Shannon; Abzug, Joshua M

    2015-01-01

    Distal radius and forearm fractures represent a large percentage of pediatric fractures. The most common mechanism of injury is a fall onto an outstretched arm, which can lead to substantial rotational displacement. If this rotational displacement is not adequately addressed, there will be resultant loss of forearm motion and subsequent limitations in performing the activities of daily living. Good initial reductions and proper casting techniques are necessary when treating distal radius and forearm fractures nonsurgically; however, maintaining an acceptable reduction is not always possible. Atraumatic reduction of a displaced physeal fracture should occur within 7 days of the injury. If an impending malunion presents at 2 weeks or later after injury, observation is warranted because of concerns about physeal arrest with repeated attempts at manipulation, and it should be followed by a later assessment of functional limitations. Pediatric patients and their parents have higher expectations for recovery, which has contributed to an increase in the surgical management of pediatric distal radius and forearm fractures. In addition, surgical interventions, such as intramedullary nailing, have their own associated complications.

  5. A novel, new robotic platform for natural orifice distal pancreatectomy.

    PubMed

    Thakkar, Shyam; Awad, Michael; Gurram, Krishna C; Tully, Steven; Wright, Cornell; Sanan, Siddharth; Choset, Howie

    2015-06-01

    Laparoendoscopic technology has revolutionized the practice of surgery; however, surgeons have not widely accepted laparoscopic techniques for pancreatic surgeries due to the complexity of the operation. Natural orifice transluminal endoscopic surgery (NOTES) offers a great new potential for pancreatic procedures, with early data showing benefits of reduced visible scarring and the potential for decreased wound infections, hernias, pain, and postoperative complications. However, there are significant limitations to the currently used flexible endoscopy tools, including a diminished visual field, spatial orientation and tissue manipulation issues, and 2-dimensional visual feedback. We have adopted a novel snake-like robot, the minimally invasive cardiac surgery (MICS) robot, which addresses these issues. In the current pilot study, the MICS robot was evaluated for transrectal distal pancreas exploration and resection in 2 nonsurvival porcine models. Abdominal navigation and accessing the pancreas was investigated in the first pig, and based on its success, pancreas resection was studied in pig 2. The MICS robot was successful in accessing and visualizing the right upper, left upper, and left lower quadrants of the abdomen in pig 1 and was able to perform a successful complex NOTES procedure with distal pancreas resection in pig 2, with only minimal laparoscopic retraction assistance. In conclusion, preliminary results showing the MICS robot in natural orifice distal pancreatectomy are positive. Enhancements to optics and instrumentation will help further increase the usability in pancreatic interventions. Future indications may include transgastric NOTES approaches, endoluminal procedures, and single-port applications.

  6. Corrective Osteotomy for Intra-Articular Distal Humerus Malunion

    PubMed Central

    Kinaci, Ahmet; Buijze, Geert A.; Leeuwen, Diederik H.van; Jupiter, Jesse B.; Marti, Rene K.; Kloen, Peter

    2016-01-01

    Background: An intra-articular distal humerus malunion can be disabling. To improve function, reduce pain and/or prevent further secondary osteoarthritis an intra-articular corrective osteotomy can be considered. Herein we present the indications, practical guidelines for pre- operative planning and surgical technique. Subsequently, we provide long-term results in a small series. Methods: We included six consecutive patients operated for intra-articular distal humerus malunion. Mean follow-up was 88 months. At lastest follow up elbow function was assessed according to standardized questionnaires and classification systems. Results: All six patients healed their osteotomies. Three patients had a postoperative complication which were treated succesfully. Range of motion improved significantly and all patients were satisfied with the outcome. The elbow performance scores were good to excellent in all. Correlation analyses showed that age and level of osteoarthritis are very strong predictors for the long-term elbow function and quality of life. Conclusion: An intra-articular corrective osteotomy for a malunited distal humerus fracture is a worthwhile procedure. Based on our results it should particularly be considered in young patients with minimal osteoarthritis and moderate to severe functional disability and/or pain. PMID:27200396

  7. Distal histidine conformational flexibility in dehaloperoxidase from Amphitrite ornata

    SciTech Connect

    Chen, Zuxu; de Serrano, Vesna; Betts, Laurie; Franzen, Stefan

    2009-01-28

    The enzyme dehaloperoxidase (DHP) from the terebellid polychaete Amphitrite ornata is a heme protein which has a globin fold but can function as both a hemoglobin and a peroxidase. As a peroxidase, DHP is capable of converting 2,4,6-trihalophenols to the corresponding 2,6-dihaloquinones in the presence of hydrogen peroxide. As a hemoglobin, DHP cycles between the oxy and deoxy states as it reversibly binds oxygen for storage. Here, it is reported that the distal histidine, His55, exhibits conformational flexibility in the deoxy form and is consequently observed in two solvent-exposed conformations more than 9.5 {angstrom} away from the heme. These conformations are analogous to the open conformation of sperm whale myoglobin. The heme iron in deoxy ferrous DHP is five-coordinate and has an out-of-plane displacement of 0.25 {angstrom} from the heme plane. The observation of five-coordinate heme iron with His55 in a remote solvent-exposed conformation is consistent with the hypothesis that His55 interacts with heme iron ligands through hydrogen bonding in the closed conformation. Since His55 is also displaced by the binding of 4-iodophenol in an internal pocket, these results provide new insight into the correlation between heme iron ligation, molecular binding in the distal pocket and the conformation of the distal histidine in DHP.

  8. Evolution of Symbiotic Bacteria in the Distal Human Intestine

    PubMed Central

    Ley, Ruth E; Lozupone, Catherine A; Hamady, Micah; Martens, Eric C; Henrissat, Bernard; Coutinho, Pedro M; Minx, Patrick; Latreille, Philippe; Cordum, Holland; Van Brunt, Andrew; Kim, Kyung; Fulton, Robert S; Fulton, Lucinda A; Clifton, Sandra W; Wilson, Richard K; Knight, Robin D; Gordon, Jeffrey I

    2007-01-01

    The adult human intestine contains trillions of bacteria, representing hundreds of species and thousands of subspecies. Little is known about the selective pressures that have shaped and are shaping this community's component species, which are dominated by members of the Bacteroidetes and Firmicutes divisions. To examine how the intestinal environment affects microbial genome evolution, we have sequenced the genomes of two members of the normal distal human gut microbiota, Bacteroides vulgatus and Bacteroides distasonis, and by comparison with the few other sequenced gut and non-gut Bacteroidetes, analyzed their niche and habitat adaptations. The results show that lateral gene transfer, mobile elements, and gene amplification have played important roles in affecting the ability of gut-dwelling Bacteroidetes to vary their cell surface, sense their environment, and harvest nutrient resources present in the distal intestine. Our findings show that these processes have been a driving force in the adaptation of Bacteroidetes to the distal gut environment, and emphasize the importance of considering the evolution of humans from an additional perspective, namely the evolution of our microbiomes. PMID:17579514

  9. Ionotropic GABA Receptors and Distal Retinal ON and OFF Responses

    PubMed Central

    Popova, E.

    2014-01-01

    In the vertebrate retina, visual signals are segregated into parallel ON and OFF pathways, which provide information for light increments and decrements. The segregation is first evident at the level of the ON and OFF bipolar cells in distal retina. The activity of large populations of ON and OFF bipolar cells is reflected in the b- and d-waves of the diffuse electroretinogram (ERG). The role of gamma-aminobutyric acid (GABA), acting through ionotropic GABA receptors in shaping the ON and OFF responses in distal retina, is a matter of debate. This review summarized current knowledge about the types of the GABAergic neurons and ionotropic GABA receptors in the retina as well as the effects of GABA and specific GABAA and GABAC receptor antagonists on the activity of the ON and OFF bipolar cells in both nonmammalian and mammalian retina. Special emphasis is put on the effects on b- and d-waves of the ERG as a useful tool for assessment of the overall function of distal retinal ON and OFF channels. The role of GABAergic system in establishing the ON-OFF asymmetry concerning the time course and absolute and relative sensitivity of the ERG responses under different conditions of light adaptation in amphibian retina is also discussed. PMID:25143858

  10. Contact areas of the scaphoid and lunate with the distal radius in neutral and extension: correlation of falling strategies and distal radial anatomy.

    PubMed

    Chen, Y R; Wu, Y F; Tang, J B; Giddins, G

    2014-05-01

    The functional neutral of wrist movement is about 10° extension yet the distal radius has a volar tilt. This has not previously been explained. Assuming that the contact area between the carpus and the distal radius increased in wrist extension this would also help stabilize the carpus on the distal radius in positions where typically there is greater loading. To test this hypothesis we reconstructed three-dimensional structures of the carpal bones and distal radius using computed tomography scans of 13 normal wrists. The contact areas of the scaphoid with the distal radius were measured and were found progressively increased from flexion 20°, neutral, extension 20°, to extension 40°. The maximal increases in the contact area of the scaphoid and the distal radius was at full wrist extension. No significant changes in the contact areas of the lunate with the distal radius were found between the different positions. The contact characteristics provide greater stability to the carpus on the distal radius, and to help spread forces from impact to the wrist reducing the transmitted peak forces and thus the risk of distal radius and carpal injuries.

  11. Radiostereometric Evaluation of Tendon Elongation After Distal Biceps Repair

    PubMed Central

    Marshall, Nathan E.; Keller, Robert A.; Okoroha, Kelechi; Guest, John Michael; Yu, Charles; Muh, Stephanie; Moutzouros, Vasilios

    2016-01-01

    Background: Operative repair of distal biceps tendon ruptures has shown successful outcomes. However, little is known about the amount of tendon or repair site lengthening after repair. Purpose/Hypothesis: The purpose of this study was to evaluate distal biceps tendon repair via intratendinous radiostereometric analysis to analyze tendon lengthening at different time intervals of healing. The hypothesis was that there is significant lengthening after repair. Study Design: Case series; Level of evidence, 4. Methods: Eleven patients with distal biceps ruptures requiring operative repair were recruited. During repair, two 2-mm tantalum beads with laser-etched holes were sutured to the distal biceps tendon. Beads were evaluated via computed tomography scans immediately postoperatively and at 16 weeks. Radiographs were obtained at time 0 and then at 4, 8, and 16 weeks postoperatively. Measurements were made using the button-to-bead and bead-to-bead distances to assess repair site elongation as well as tendon elongation over time. After final follow-up, patients filled out the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire and underwent ultrasound to confirm the integrity of the tendon. Results: Ten patients had complete ruptures, with 1 having a partial rupture that underwent completion of the tear and subsequent repair. All patients showed statistically significant lengthening after surgery. The mean amount of tendon lengthening after surgery was 22.8 mm (range, 11.2-30.9 mm; P < .05), and the repair site lengthened a mean 17.0 mm (range, 9.6-30.6 mm; P < .05) from surgery to final follow-up. The greatest change in lengthening was noted between time 0 and week 4 (mean, 11.3 mm; P < .05), with the least amount of lengthening between weeks 8 and 16 (mean, 2.6 mm; P < .05). The mean DASH score was 11.2. Final ultrasound evaluations found all tendons to be in continuity. Conclusion: All patients undergoing distal biceps tendon repair have significant

  12. Anti-MAG/SGPG associated neuropathy does not commonly cause distal nerve temporal dispersion.

    PubMed

    Gondim, F A A; De Sousa, E A; Latov, N; Sander, H W; Chin, R L; Brannagan, T H

    2007-08-01

    Patients with anti-myelin associated glycoprotein (anti-MAG) neuropathy have uniform slowing without temporal dispersion, but do usually have disproportionately distal slowing. We evaluated distal compound muscle action potential (CMAP) dispersion in 29 patients with anti-MAG/sulphated glucuronyl paragloboside (SGPG) neuropathy (titres > or = 12,800). Among 138 motor responses, 15% (tibial), 7.3% (peroneal), 10.7% (median) and 13.8% (ulnar) had distal CMAP duration > 9 ms. Disproportionate distal slowing with normal distal CMAP duration in the arms may be useful to differentiate chronic inflammatory demyelinating polyneuropathy from anti-MAG/SGPG associated neuropathy.

  13. Radiographic Outcomes of Volar Locked Plating for Distal Radius Fractures

    PubMed Central

    Mignemi, Megan E.; Byram, Ian R.; Wolfe, Carmen C.; Fan, Kang-Hsien; Koehler, Elizabeth A.; Block, John J.; Jordanov, Martin I.; Watson, Jeffry T.; Weikert, Douglas R.; Lee, Donald H.

    2013-01-01

    Purpose To assess the ability of volar locked plating to achieve and maintain normal radiographic parameters for articular stepoff, volar tilt, radial inclination, ulnar variance, and radial height in distal radius fractures. Methods We performed a retrospective review of 185 distal radius fractures that underwent volar locked plating with a single plate design over a 5-year period. We reviewed radiographs and recorded measurements for volar tilt, radial inclination, ulnar variance, radial height, and articular stepoff. We used logistic regression to determine the association between return to radiographic standard norms and fracture type. Results At the first and final postoperative follow-up visits, we observed articular congruence less than 2 mm in 92% of fractures at both times. Normal volar tilt (11°) was restored in 46% at the first follow-up and 48% at the final one. Radial inclination (22°) was achieved in 44% at the first follow-up and 43% at the final one, and ulnar variance (01 ± 2 mm) was achieved in 53% at the first follow-up and 53% at the final one. In addition, radial height (14 ± 1mm) was restored in 14% at the first follow-up and 12% at the final one. More complex, intra-articular fractures (AO class B and C and Frykman types 3, 4, 7, and 8) were less likely to be restored to normal radiographic parameters. However, because of the small sample size for some fracture types, it was difficult to discover significant associations between fracture type and radiographic outcome. Conclusions Volar locked plating for distal radius fractures achieved articular stepoff less than 2 mm in most fractures but only restored and maintained normal radiographic measurements for volar tilt, radial inclination, and ulnar variance in 50% of fractures. The ability of volar locked plating to restore and maintain ulnar variance and volar tilt decreased with more complex intra-articular fracture types. PMID:23218558

  14. Secretion of acid and base equivalents by intact distal airways.

    PubMed

    Inglis, S K; Wilson, S M; Olver, R E

    2003-05-01

    Secretion of HCO(3)(-) by airway submucosal glands is essential for normal liquid and mucus secretion. Because the liquid bathing the airway surface (ASL) is acidic, it has been proposed that the surface epithelium may acidify HCO(3)(-)-rich glandular fluid. The aim of this study was to investigate the mechanisms by which intact distal bronchi, which contain both surface and glandular epithelium, modify pH of luminal fluid. Distal bronchi were isolated from pig lungs, cannulated in a bath containing HCO(3)(-)-buffered solution, and perfused continually with an aliquot of similar, lightly buffered solution (LBS) in which NaCl replaced NaHCO(3)(-) (pH 7 with NaOH). The pH of this circulating LBS initially acidified (by 0.053 +/- 0.0053 pH units) and transepithelial potential difference (PD) depolarized. The magnitude of acidification was increased when pH(LBS) was higher. This acidification was unaffected by luminal dimethylamiloride (DMA, 100 microM) but was inhibited by 100 nM bafilomycin A(1) (by 76 +/- 13%), suggesting involvement of vacuolar-H(+) ATPase. Addition of ACh (10 microM) evoked alkalinization of luminal LBS and hyperpolarization of transepithelial PD. The alkalinization was inhibited in HCO(3)(-)-free solutions containing acetazolamide (1 mM) and by DMA and was enhanced by bumetanide (100 microM), an inhibitor of Cl(-) secretion. The hyperpolarization was unaffected by these maneuvers. The anion channel blocker 5-nitro-2-(3-phenylpropylamino)benzoate (300 microM) and combined treatment with DMA and bumetanide blocked both the alkalinization and hyperpolarization responses to ACh. These results are consistent with earlier studies showing that ACh evokes glandular secretion of HCO(3)(-) and Cl(-). Isolated distal airways thus secrete both acid and base equivalents.

  15. Outcome Assessment after Aptis Distal Radioulnar Joint (DRUJ) Implant Arthroplasty

    PubMed Central

    Kachooei, Amir Reza; Chase, Samantha M; Jupiter, Jesse B

    2014-01-01

    Background: Conventional treatments after complicated injuries of the distal radioulnar joint (DRUJ) such as Darrach and Kapandji-Sauvé procedures have many drawbacks, which may eventually lead to a painful unstable distal ulna. The development of DRUJ prosthesis has significantly evolved over the past years. In this study, we assessed the outcome results of patients after DRUJ implant arthroplasty using the Aptis (Scheker) prosthesis. Methods: We identified 13 patients with 14 prosthesis during the past 10 years. Patients underwent DRUJ arthroplasty due to persistent symptoms of instability, chronic pain, and stiffness. Records and follow-up visits were reviewed to find the final post-operative symptoms, pain, range of motion, and grip strength with a mean follow-up of 12 months (range: 2-25 months). Also, patients were contacted prospectively by phone in order to administer the disabilities of the arm shoulder and hand (DASH), patient rated wrist evaluation (PRWE), and visual analogue scale (VAS), and to interview regarding satisfaction and progress in daily activities. Eleven patients out of 13 could be reached with a median follow-up time of 60 months (range: 2 to 102 months). Results: No patient required removal of the prosthesis. Only two patients underwent secondary surgeries in which both required debridement of the screw tip over the radius. The median DASH score, PRWE score, VAS, and satisfaction were 1.3, 2.5, 0, and 10, respectively. The mean range of flexion, extension, supination, and pronation was 62, 54, 51, and 64, respectively. Conclusions: Distal radioulnar joint injuries are disabling and patients usually undergo one or more salvage surgeries prior to receiving an arthroplasty. The Scheker prosthesis has shown satisfactory results with 100% survival rate in all reports. The constrained design of this prosthesis gives enough stability to prevent painful subluxation. PMID:25386579

  16. Enchondroma in the distal phalanx of the finger

    PubMed Central

    Lu, Hui; Chen, Qiang; Yang, Hu; Shen, Hui

    2016-01-01

    Abstract The goal of our study was to report the clinical presentation, treatment, and complications of enchondroma in the distal phalanx of the finger. This was a retrospective study of 34 patients (19 women and 15 men) who underwent surgery between May 2004 and September 2012 for enchondroma in the distal phalanx of the finger. The average age of the patients was 39.38 ± 10.97 years old (range 14–59). The presenting symptoms and imaging features were recorded. The surgical procedure was performed under regional or general anesthesia. The surgical technique involved removal of tumors by opening a cortical window and curetting the cavity. The defects were filled with an injectable calcium phosphate cement. All patients received follow-up in our outpatient clinic every 6 months. Expansion of bone or thinning of the cortex present in the radiological imaging, including anteroposterior and lateral plain radiographs of the fingers, was used to assess for tumor recurrence. The observational end-point was reoperation. All tumors were confirmed as enchondromas by the pathological results. None of the patients had a tumor recurrence. Three patients (9% of cases) developed an infection. After antibiotic treatment, 2 patients were cured, and 1 patient required an amputation. Enchondroma in the distal phalanx of the finger presents with a variety of clinical symptoms. Injectable calcium phosphate cement is adequate for bone grafting. Postoperative infection is more common than tumor recurrence. If patients have an infection or bilateral bone cortex defects, bone grafting is challenging. Level of Evidence: Therapeutic study, Level IV PMID:27661057

  17. Fractal analysis of bone architecture at distal radius.

    PubMed

    Tomomitsu, Tatsushi; Mimura, Hiroaki; Murase, Kenya; Sone, Teruki; Fukunaga, Masao

    2005-12-20

    Bone strength depends on bone quality (architecture, turnover, damage accumulation, and mineralization) as well as bone mass. In this study, human bone architecture was analyzed using fractal image analysis, and the clinical relevance of this method was evaluated. The subjects were 12 healthy female controls and 16 female patients suspected of having osteoporosis (age range, 22-70 years; mean age, 49.1 years). High-resolution CT images of the distal radius were acquired and analyzed using a peripheral quantitative computed tomography (pQCT) system. On the same day, bone mineral densities of the lumbar spine (L-BMD), proximal femur (F-BMD), and distal radius (R-BMD) were measured by dual-energy X-ray absorptiometry (DXA). We examined the correlation between the fractal dimension and six bone mass indices. Subjects diagnosed with osteopenia or osteoporosis were divided into two groups (with and without vertebral fracture), and we compared measured values between these two groups. The fractal dimension correlated most closely with L-BMD (r=0.744). The coefficient of correlation between the fractal dimension and L-BMD was very similar to the coefficient of correlation between L-BMD and F-BMD (r=0.783) and the coefficient of correlation between L-BMD and R-BMD (r=0.742). The fractal dimension was the only measured value that differed significantly between both the osteopenic and the osteoporotic subjects with and without vertebral fracture. The present results suggest that the fractal dimension of the distal radius can be reliably used as a bone strength index that reflects bone architecture as well as bone mass.

  18. Congenital deformity of the distal extremities in three dogs

    PubMed Central

    Di Dona, F.; Valle, G. Della; Meomartino, L.; Lamagna, F.; Fatone, G.

    2016-01-01

    Congenital limb deformities are very rare conditions and the knowledge about etiology, pathogenesis, clinical presentation and treatment is still poor. Moreover, many defects are still not reported in veterinary literature. This report documents clinical and radiographic findings in three dogs with congenital deformity involving the distal extremities. Case 1 was affected with bilateral aphalangia of the pedes, case 2 presented a combination of brachydactyly and syndactyly, whereas in case 3 a unilateral ectrodactyly was observed. To the authors’ knowledge, brachydactyly, as well as aphalangia, are very uncommon anomalies and have been rarely documented. Moreover, association between syndactyly and brachydactyly has still not been reported. PMID:27928521

  19. Primary Combined Replacements for Treatment of Distal Radius Physeal Arrest

    PubMed Central

    Schmidt, Ingo

    2014-01-01

    This is a case report of a 59-year-old female patient with a posttraumatic growth arrest of the distal radius, leading to radioscaphoid osteoarthritis, carpal instability, and a symptomatic ulnocarpal impaction syndrome that was successfully treated with combined total wrist arthroplasty and ulnar head implant. One year postoperatively, there was no change in position without any signs of loosening of both implants. Both subjectively and functionally, all clinical parameters—Disabilities of the Arm, Shoulder, and Hand (DASH), visual analog scale (VAS), grip strength—had improved. Level of Evidence: IV PMID:25097815

  20. Absence of distal interphalangeal creases of fingers with flexion limitation.

    PubMed Central

    Fried, K; Mundel, G

    1976-01-01

    An Ashkenazi Jewish family is described, in which absence of distal interphalangeal creases of fingers with flexion limitation is transmitted through 4 generations with 8 affected individuals. The malformation is caused by an autosomal dominant gene with full penetrance and variable expressivity, and causes only little inconvenience. In one case the joints were normal on radiological examination. The malformation was not associated with any other anomaly except in the propositus who was referred becaused of profound mental retardation and cerebral palsy. This association is probably fortuitous as the other affected members were of above average intelligence. We were unable to find any report on this anomaly without associated malformations. Images PMID:933109

  1. Absence of distal interphalangeal creases of fingers with flexion limitation.

    PubMed

    Fried, K; Mundel, G

    1976-04-01

    An Ashkenazi Jewish family is described, in which absence of distal interphalangeal creases of fingers with flexion limitation is transmitted through 4 generations with 8 affected individuals. The malformation is caused by an autosomal dominant gene with full penetrance and variable expressivity, and causes only little inconvenience. In one case the joints were normal on radiological examination. The malformation was not associated with any other anomaly except in the propositus who was referred becaused of profound mental retardation and cerebral palsy. This association is probably fortuitous as the other affected members were of above average intelligence. We were unable to find any report on this anomaly without associated malformations.

  2. Stabilisation of distal radius fractures: Lessons learned and future directions.

    PubMed

    Horst, Taylor A; Jupiter, Jesse B

    2016-02-01

    Our understanding of the diagnosis and management of distal radius fractures has been a long developed over centuries. There has been a shift in treatment of these very common injuries from closed reduction and casting to internal fixation. The answer to the best method of treatment has yet to be found. Today, we have a multitude of treatment options available with varying degrees of evidence to support their use. This review helps to illustrate the lessons we have learned and future directions for treatment.

  3. Propylene oxide causes central-peripheral distal axonopathy in rats

    SciTech Connect

    Ohnishi, A.; Yamamoto, T.; Murai, Y.; Hayashida, Y.; Hori, H.; Tanaka, I.

    1988-09-01

    In Wistar rats subjected daily to a 6-hr exposure of propylene oxide (PO) at a concentration of 1,500 ppm (5 times a wk for 7 wk), ataxia developed in the hindlegs. Myelinated fibers in hindleg nerves and in the fasciculus gracilis showed axonal degeneration, sparing the nerve cell body of the first sacral dorsal root ganglion and myelinated fibers of the first sacral dorsal and ventral roots. These pathologic findings are compatible with central-peripheral distal axonopathy. This is apparently the first animal model of PO neuropathy to be verified histologically.

  4. Portico Sheathless Transcatheter Aortic Valve Implantation via Distal Axillary Artery.

    PubMed

    Bruschi, Giuseppe; Colombo, Paola; Botta, Luca; Nava, Stefano; Merlanti, Bruno; Belli, Oriana; Musca, Francesco; Soriano, Francesco; Russo, Claudio F; Oliva, Fabrizio

    2017-02-01

    Transcatheter aortic valve implantation has been designed to treat older patients affected by severe aortic stenosis who are considered high-risk surgical candidates because of multiple comorbidities. The least invasive approach for transcatheter aortic valves implantation should be considered the transfemoral retrograde route, because it is minimally invasive and is feasible with local anesthesia and mild sedation. Despite significant technical improvements in recent years, the transfemoral approach is contraindicated in cases of severe peripheral artery disease. We describe the first case of a Portico transcatheter aortic valve implantation system (St. Jude Medical, Minneapolis, MN) made through the distal axillary artery in a 90-year-old patient affected by severe aortic stenosis.

  5. Measurement of ulnar variance and radial inclination on X-rays of healed distal radius fractures. With the axis of the distal radius or ulna?

    PubMed

    Thuysbaert, Gilles; Ringburg, Akkie; Petronilia, Steven; Vanden Berghe, Alex; Hollevoet, Nadine

    2015-06-01

    Ulnar variance and radial inclination are radiological parameters frequently used to evaluate displacement of distal radius fractures. In most studies measurements are based on the long central axis of the distal radius, although the axis of the distal ulna can also be used. The purpose of this study was to determine which axis is more reliable. Four observers performed measurements on standard anteroposterior digital wrist X-rays of 20 patients taken 1 and 2 months after sustaining an extra-articular distal radius fracture. Intraobserver reliability was similar with both methods. No difference was found in interobserver reliability between both methods for ulnar variance, but for radial inclination it was better with the axis through the radius. Measurements on two X-rays of the same wrist taken at a different moment were similar with both methods. It can be concluded that the central axis of the distal radius can remain the basis to determine ulnar variance and radial inclination.

  6. Spinal irradiation does not inhibit distal axonal sprouting

    SciTech Connect

    Pamphlett, R.S.

    1988-05-01

    In an attempt to determine the relative importance of the nerve cell body and of the axon in initiating and controlling axonal regeneration, nerve cell bodies were irradiated and the ability of the distal axon to sprout was examined. Mice were subjected to either 25 or 50 Gray (Gy) of x-irradiation localized to the lumbar spinal cord. After times varying from 1 day to 6 months after irradiation, a sublethal dose of botulinum toxin (BoTx) was injected into the calf muscles of one leg. The soleus muscle was examined histologically after times varying from 1 week to 6 months after injection, and BoTx-induced ultraterminal axonal sprouting was assessed by the number of motor endplates showing sprouts, the length of the sprouts, and the long term endplate morphology. Apart from some irradiated subgroups having slightly shorter sprout lengths, no significant differences were found between irradiated and nonirradiated groups. The results suggest either that the processes in the nerve cell body responsible for initiating and supporting axonal growth are resistant to large doses of irradiation, or that growth regulatory mechanisms in the distal axon are under local control.

  7. Pediatric distal radius fractures and triangular fibrocartilage complex injuries.

    PubMed

    Bae, Donald S; Waters, Peter M

    2006-02-01

    Management of distal radius fractures is guided by the pattern and location of injury, degree of deformity, and expectations of bony remodeling based on the amount of remaining skeletal growth.Indications for surgical treatment include unstable or irreducible fractures, open fractures, floating elbow injuries, and neurovascular or soft-tissue compromise precluding cast immobilization. Patients and families should be counseled regarding the potential for post-traumatic distal radial growth arrest following physeal fractures. In these cases, epiphysiodeses, ulnar shortening osteotomies, or corrective radial osteotomies may be performed, depending on the pattern of arrest,degree of deformity, and remaining skeletal growth.TFCC tears may be the source of ulnar-sided wrist pain in children and adolescents, though symptoms and physical examination findings maybe subtle. Patients who have persistent pain and functional limitations despite activity modification and therapy are candidates for surgical treatment. Appropriate repair of peripheral TFCC tears with correction of concomitant wrist pathology restores normal wrist anatomy, alleviates pain, and allows for return to functional activities.

  8. Epimorphic regeneration of the distal part of the planarian pharynx.

    PubMed

    Ito, H; Saito, Y; Watanabe, K; Orii, H

    2001-01-01

    The totipotent stem cells called neoblasts seem to be concerned with the remarkable regeneration ability of planarians. However, the pharynx is able to regenerate after the amputation of its distal part, in spite of a lack of neoblasts in the pharynx. The process of regeneration has been referred to as morphallaxis, based on conventional histochemical observations. We examined it again immuno-histochemically using anti-Dugesia japonica proliferating cell nuclear antigen (DjPCNA) antibody for neoblasts and anti-D. japonica myosin heavy chain-A (DjMHC-A) antibody for pharynx muscle fibers. This immuno-histochemical study, together with observations of the regeneration process of planarians irradiated with X-rays in particular regions, revealed that after the amputation, neoblasts from outside the pharynx entered that organ, moved through the mesenchyme of the pharynx to the wounded area, and differentiated into the cells that had been lost there. We show here that the regeneration after amputation of the distal part of the pharynx is an 'epimorphic' process.

  9. Distal Femoral Oblique Fracture in a Young Male Soldier

    PubMed Central

    Cohen, David Naji; Al Khateeb, Hesham; Safwat, Mohammed

    2016-01-01

    Abstract Here, we report a case of a distal femoral fracture in a 23-year-old male army cadet who presented to the Accident and Emergency department following a twisting injury while participating in a routine military marching exercise. A pathological fracture was considered but this suspicion was put to rest following thorough investigations, leaving only a diagnosis of a nontraumatic spontaneous femoral fracture. To our knowledge, there have been no reported cases of distal femoral fractures associated with nontraumatic military exercises, with the majority of injuries instead related to stress fractures. A vigilant literature search yielded no cases of similar injury nature, which is the primary reason we believe that those interested in orthopaedics or military doctors would find themselves drawn to this case. The patient presented with severe pain in his left thigh and on examination there was a deformity of his left thigh. In terms of investigations, a bone profile, plain film radiographs, C-reactive protein, erythrocyte sedimentation rate, and tumor markers were all preformed and proved unremarkable. The definitive treatment was by open reduction and internal fixation. Femoral fractures often require significant amounts of force, particularly in young, healthy individuals. Generally, these injuries in this demographic follow high-energy traumas, with the lion's share occurring following a road traffic accident or other high-speed impact. More often than not, the treatment is surgical. Given the extraordinary manner of this such, one must be attentive and exhaustive in their investigation of such presentations. PMID:27258509

  10. Afferent input regulates the formation of distal dendritic branches.

    PubMed

    Mizrahi, Adi; Libersat, Frederic

    2002-10-07

    During postembryonic development, the dendritic arbors of neurons grow to accommodate new incoming synaptic inputs. Our goal was to examine which features of dendritic architecture of postsynaptic interneurons are regulated by these synaptic inputs. To address this question, we took advantage of the cockroach cercal system where the morphology of the sensory giant interneurons (GIs) is uniquely identified and, therefore, amenable to quantitative analysis. We analyzed the three-dimensional architecture of chronically deafferented vs. normally developed dendritic trees of a specific identified GI, namely GI2. GI2 shows five prominent dendrites, four of which were significantly altered after deafferentation. De-afferentation induced an average of 55% decrease in metric measures (number of branch points, total length, and total surface area) on the entire dendritic tree. Sholl and branch order analysis showed a decrease in the most distal and higher order branches. We suggest that afferent input plays a specific role in shaping the morphology of dendritic trees by regulating the formation or maintenance of high-order distal branches.

  11. MR appearance of distal femoral cortical irregularity (cortical desmoid)

    SciTech Connect

    Suh, Jin-Suck; Cho, Jae-Hyun; Shin, Kyoo-Ho

    1996-03-01

    Our goal was to describe the MR appearance of distal femoral cortical irregularity (DFCI). With plain radiographs and MR images of 100 knees, the presence of DFCIs was determined, and the shapes of DFCIs were classified into three subgroups: concave, convex, and divergent cortical shapes. Radiographic and MR shapes of DFCIs were compared. DFCIs were shown in various shapes on both the radiographs and the MR images. Forty-four DFCIs were found both on radiograph and by MR image. An additional 14 DFCIs were identifiable only on MR images. However, the majority of DFCIs showed an association between radiographic and MR shapes. MRI revealed that all 58 DFCIs were located at the attachment site of the media gastrocnemius muscle. DFCIs were enhanced in three of the four patients who underwent postcontrast MR study. A good understanding of radiographic and MR findings of the DFCI may be of great help in the differential diagnosis of distal femoral lesions. 16 refs., 6 figs., 1 tab.

  12. Do CT scans aid assessment of distal tibial physeal fractures?

    PubMed

    Cutler, L; Molloy, A; Dhukuram, V; Bass, A

    2004-03-01

    Distal tibial physeal fractures are the second most common growth plate injury and the most common cause of growth arrest and deformity. This study assesses the accuracy of pre-operative planning for placement of the screws in these fractures using either standard radiographs or CT scans. We studied 62 consecutive physeal fractures over a period of four years. An outline of a single cut of the CT scan was used for each patient. An ideal position for the screw was determined as being perpendicular to and at the midpoint of the fracture. The difference in entry point and direction of the screw between the ideal and the observers' assessments were compared using the paired Student's t-test. There was a statistically significant improvement (p < 0.0001) in the accuracy of the point of insertion and the direction of the screw on the pre-operative plan when CT scans were used rather than plain radiographs. We would, therefore, recommend that CT scans are routinely used in the pre-operative assessment and treatment of distal tibial physeal fractures.

  13. Interactions between distal speech rate, linguistic knowledge, and speech environment.

    PubMed

    Morrill, Tuuli; Baese-Berk, Melissa; Heffner, Christopher; Dilley, Laura

    2015-10-01

    During lexical access, listeners use both signal-based and knowledge-based cues, and information from the linguistic context can affect the perception of acoustic speech information. Recent findings suggest that the various cues used in lexical access are implemented with flexibility and may be affected by information from the larger speech context. We conducted 2 experiments to examine effects of a signal-based cue (distal speech rate) and a knowledge-based cue (linguistic structure) on lexical perception. In Experiment 1, we manipulated distal speech rate in utterances where an acoustically ambiguous critical word was either obligatory for the utterance to be syntactically well formed (e.g., Conner knew that bread and butter (are) both in the pantry) or optional (e.g., Don must see the harbor (or) boats). In Experiment 2, we examined identical target utterances as in Experiment 1 but changed the distribution of linguistic structures in the fillers. The results of the 2 experiments demonstrate that speech rate and linguistic knowledge about critical word obligatoriness can both influence speech perception. In addition, it is possible to alter the strength of a signal-based cue by changing information in the speech environment. These results provide support for models of word segmentation that include flexible weighting of signal-based and knowledge-based cues.

  14. A biomechanical approach to distal radius fractures for the emergency radiologist.

    PubMed

    Bunch, Paul M; Sheehan, Scott E; Dyer, George S; Sodickson, Aaron; Khurana, Bharti

    2016-04-01

    Distal radius fractures are the most common upper extremity fracture and account for approximately one sixth of all fractures treated in US emergency departments. These fractures are associated with significant morbidity and have a major economic impact. Radiographic evaluation of distal radius fractures is frequently performed in the emergency department setting, has a profound impact on initial management, and is essential to assessing the quality and relative success of the initial reduction. While the most appropriate definitive management of distal radius fractures remains controversial, overarching treatment principles reflect distal radius injury mechanisms and biomechanics. An intuitive understanding of the biomechanics of the distal radius and of common mechanisms of injury informs and improves the emergency radiologist's ability to identify key imaging findings with important management implications and to communicate the critical information that emergency physicians and orthopedic surgeons need to best manage distal radius fractures.

  15. Involvement of dachshund and Distal-less in distal pattern formation of the cricket leg during regeneration.

    PubMed

    Ishimaru, Yoshiyasu; Nakamura, Taro; Bando, Tetsuya; Matsuoka, Yuji; Ohuchi, Hideyo; Noji, Sumihare; Mito, Taro

    2015-02-11

    Cricket nymphs have the remarkable ability to regenerate a functional leg following amputation, indicating that the regenerating blastemal cells contain information for leg morphology. However, the molecular mechanisms that underlie regeneration of leg patterns remain poorly understood. Here, we analyzed phenotypes of the tibia and tarsus (three tarsomeres) obtained by knockdown with regeneration-dependent RNA interference (rdRNAi) against Gryllus dachshund (Gb'dac) and Distal-less (Gb'Dll). We found that depletion of Gb'Dll mRNA results in loss of the tarsal segments, while rdRNAi against Gb'dac shortens the tibia at the two most distal tarsomeres. These results indicate that Gb'Dll expression is indispensable for formation of the tarsus, while Gb'dac expression is necessary for elongation of the tibia and formation of the most proximal tarsomere. These findings demonstrate that mutual transcriptional regulation between the two is indispensable for formation of the tarsomeres, whereas Gb'dac is involved in determination of tibial size through interaction with Gb'ds/Gb'ft.

  16. Involvement of dachshund and Distal-less in distal pattern formation of the cricket leg during regeneration

    PubMed Central

    Ishimaru, Yoshiyasu; Nakamura, Taro; Bando, Tetsuya; Matsuoka, Yuji; Ohuchi, Hideyo; Noji, Sumihare; Mito, Taro

    2015-01-01

    Cricket nymphs have the remarkable ability to regenerate a functional leg following amputation, indicating that the regenerating blastemal cells contain information for leg morphology. However, the molecular mechanisms that underlie regeneration of leg patterns remain poorly understood. Here, we analyzed phenotypes of the tibia and tarsus (three tarsomeres) obtained by knockdown with regeneration-dependent RNA interference (rdRNAi) against Gryllus dachshund (Gb'dac) and Distal-less (Gb'Dll). We found that depletion of Gb'Dll mRNA results in loss of the tarsal segments, while rdRNAi against Gb'dac shortens the tibia at the two most distal tarsomeres. These results indicate that Gb'Dll expression is indispensable for formation of the tarsus, while Gb'dac expression is necessary for elongation of the tibia and formation of the most proximal tarsomere. These findings demonstrate that mutual transcriptional regulation between the two is indispensable for formation of the tarsomeres, whereas Gb'dac is involved in determination of tibial size through interaction with Gb'ds/Gb'ft. PMID:25669615

  17. Fracture of the distal radial physis complicated by compartment syndrome and premature physeal closure.

    PubMed

    Hernandez, J; Peterson, H A

    1986-01-01

    Complications after injury to the epiphyseal growth plate of the distal radius are uncommon. An 11-year-8-month-old boy developed two complications--compartment syndrome of the forearm and premature closure of the physis--after a Salter-Harris Type I injury. Treatment included closed reduction, decompression, skin grafting, excision of the physeal bar, and epiphysiodesis of the distal ulna and the remaining open physis of the distal radius.

  18. Excessive distal migration of fiber-mesh coated femoral stems

    PubMed Central

    2011-01-01

    Background The surface texture, localization, and magnitude of the surface material applied to the femoral stem can facilitate bone ingrowth and influence the survival of total hip arthroplasties. Clinical and radiographic studies have shown superior bone ingrowth in proximally porous-coated stems with a diaphyseal grit-blasted surface in comparison to a smooth diaphyseal surface. Surface textures—especially porous surface material—have been suggested to have a sealing effect against migration of polyethylene debris along the implant-bone interface and to reduce the inflammatory response, leading to a prolonged implant survival. Patients and methods Between 2004 and 2006, we conducted a randomized, controlled trial (RCT) involving 50 patients with non-inflammatory arthritis. They received either a distally tapered, extended coated stem or a straight, proximally coated stem. During surgery, tantalum markers were inserted into the greater and lesser trochanter. Implant migration was evaluated at 3, 12, and 24 months postoperatively by radiostereometric analysis. The primary endpoint was stem migration 2 years after surgery. Results All femoral components in both groups showed pronounced distal translation, with the highest rate of translation occurring between 0 and 3 months. After 2 years, the mean distal translation was 2.67 (95% CI: –3.93 to –1.42) mm for the tapered, extended coated stem and 1.80 (–2.45 to –1.15) mm for the straight, proximally coated stem. Half of the tapered, extended coated stems and two-thirds of the straight, proximally coated stems had migrated more than 1 mm. No difference between the 2 stems could be seen with regard to translation or rotation at any time point. After 2 years, 2 hips have been reoperated due to mechanical loosening of the stem. Interpretation An excessive amount of migration of both stem types was seen 2 years postoperatively. It is of vital importance to follow this patient cohort since radiostereometric

  19. [Results of using composite bypass grafts with infragenicular distal anastomosis].

    PubMed

    Pokrovskiĭ, A V; Iakhontov, D I

    2014-01-01

    The authors share herein their experience with composite bypass grafts and PTFE synthetic prostheses used for treatment of obliterating diseases of the infrainguinal-segment arteries. The data of the study were based on the outcomes obtained in 92 patients. The authors assessed the condition of the outflow pathways and their effect on patency of composite bypass grafts in the immediate and remote postoperative periods, followed by comparative analysis of the short- and long-term therapeutic outcomes after using composite bypass grafts and PTFE synthetic prostheses in the infragenicular position for femoropopliteal and femorotibial reconstructions, also assessing the effect of the localization of the distal anastomosis on the immediate and remote therapeutic outcomes. Based on the obtained findings it was determined that the immediate results of patency depended upon the state of the outflow pathways and localization of the distal anastomosis. Thus, by the 1st, 3rd and 5th year of follow up patency of transplants in patients with the runoff score less than 7.0 amounted to 78.3, 21.7 and 4.3%, respectively. Analogous indices of patency in patients with the runoff score equalling or greater than 7.0 amounted to 60.7 and 3.6% for the 1st and 3rd year, respectively. The remote results of patency turned out to depend on the type of a vascular transplant and the state of the outflow pathways and did not depend on the localization of the distal anastomosis. Thus, the remote results of patency for the composite bypass graft for the 1st, 3rd and 5th year of follow up amounted to 74.5, 19.6 and 5.9%, respectively, versus 60.8 and 8.6% by the first and third year for the PTFE prosthesis. The limb salvage rate at the same terms for the composite bypass graft amounted to 94.1, 84.3 and 78.4% versus 73.9, 56.5 and 52.2% for the PTFE prosthesis.

  20. Architectural properties of distal forelimb muscles in horses, Equus caballus.

    PubMed

    Brown, Nicholas A T; Kawcak, Christopher E; McIlwraith, C Wayne; Pandy, Marcus G

    2003-10-01

    Articular injuries in athletic horses are associated with large forces from ground impact and from muscular contraction. To accurately and noninvasively predict muscle and joint contact forces, a detailed model of musculoskeletal geometry and muscle architecture is required. Moreover, muscle architectural data can increase our understanding of the relationship between muscle structure and function in the equine distal forelimb. Muscle architectural data were collected from seven limbs obtained from five thoroughbred and thoroughbred-cross horses. Muscle belly rest length, tendon rest length, muscle volume, muscle fiber length, and pennation angle were measured for nine distal forelimb muscles. Physiological cross-sectional area (PCSA) was determined from muscle volume and muscle fiber length. The superficial and deep digital flexor muscles displayed markedly different muscle volumes (227 and 656 cm3, respectively), but their PCSAs were very similar due to a significant difference in muscle fiber length (i.e., the superficial digital flexor muscle had very short fibers, while those of the deep digital flexor muscle were relatively long). The ulnaris lateralis and flexor carpi ulnaris muscles had short fibers (17.4 and 18.3 mm, respectively). These actuators were strong (peak isometric force, Fmax=5,814 and 4,017 N, respectively) and stiff (tendon rest length to muscle fiber length, LT:LMF=5.3 and 2.1, respectively), and are probably well adapted to stabilizing the carpus during the stance phase of gait. In contrast, the flexor carpi radialis muscle displayed long fibers (89.7 mm), low peak isometric force (Fmax=555 N), and high stiffness (LT:LMF=1.6). Due to its long fibers and low Fmax, flexor carpi radialis appears to be better adapted to flexion and extension of the limb during the swing phase of gait than to stabilization of the carpus during stance. Including muscle architectural parameters in a musculoskeletal model of the equine distal forelimb may lead to

  1. Fatigue strength of common tibial intramedullary nail distal locking screws

    PubMed Central

    Griffin, Lanny V; Harris, Robert M; Zubak, Joseph J

    2009-01-01

    Background Premature failure of either the nail and/or locking screws with unstable fracture patterns may lead to angulation, shortening, malunion, and IM nail migration. Up to thirty percent of all unreamed nail locking screws can break after initial weight bearing is allowed at 8–10 weeks if union has not occurred. The primary problem this presents is hardware removal during revision surgery. The purposes of our study was to evaluate the relative fatigue resistance of distal locking screws and bolts from representative manufacturers of tibial IM nail systems, and develop a relative risk assessment of screws and materials used. Evaluations included quantitative and qualitative measures of the relative performance of these screws. Methods Fatigue tests were conducted to simulate a comminuted fracture that was treated by IM nailing assuming that all load was carried by the screws. Each screw type was tested ten times in a single screw configuration. One screw type was tested an additional ten times in a two-screw parallel configuration. Fatigue tests were performed using a servohydraulic materials testing system and custom fixturing that simulated screws placed in the distal region of an appropriately sized tibial IM nail. Fatigue loads were estimated based on a seventy-five kilogram individual at full weight bearing. The test duration was one million cycles (roughly one year), or screw fracture, whichever occurred first. Failure analysis of a representative sample of titanium alloy and stainless steel screws included scanning electron microscopy (SEM) and quantitative metallography. Results The average fatigue life of a single screw with a diameter of 4.0 mm was 1200 cycles, which would correspond roughly to half a day of full weight bearing. Single screws with a diameter of 4.5 mm or larger have approximately a 50 percent probability of withstanding a week of weight bearing, whereas a single 5.0 mm diameter screw has greater than 90 percent probability of

  2. Cranial nerves palsy as an initial feature of an early onset distal hereditary motor neuropathy--a new distal hereditary motor neuropathy phenotype.

    PubMed

    Haberlová, J; Claeys, K G; De Jonghe, P; Seeman, P

    2009-06-01

    Distal hereditary motor neuropathy is a heterogeneous group of disorders characterised by a pure motor axonal neuropathy. It is occasionally associated with additional signs such as facial weakness, vocal cord paralysis, weakness of the diaphragm, and pyramidal signs. Although predominantly the inheritance is autosomal dominant, all types of inheritance have been described. Here we report a Czech family with cranial nerves palsy as an initial feature of a non progressive infantile onset dominant distal hereditary motor neuropathy. This family may represent a new subtype of distal hereditary motor neuropathy.

  3. Abdominal x-ray and pathological findings in distal unishunt obstruction.

    PubMed

    Le Roux, P; Berger, M; Benjamin, D

    1988-12-01

    A new x-ray finding suggesting distal obstruction of the Unishunt is described. Fusiform swelling of the distal slit valve ("pantaloon sign") seen on an abdominal x-ray film was associated with surgically proven distal shunt obstruction in 8 of 10 patients. No patient with a normally functioning (n = 67) or proximally malfunctioning shunt (n = 6) displayed this abnormality. This finding in association with clinical and computed tomographic evidence of shunt malfunction can direct surgical revision to the appropriate site. The pathology of distal shunt malfunction is also reviewed.

  4. Arthroscopic excision of distal pole of patella for refractory patellar tendinitis.

    PubMed

    Kelly, John D

    2009-07-01

    This article examines the results of arthroscopic tendon debridement with excision of the distal pole of the patella for refractory patellar tendinitis. Nine patients failed at least 3 months of conservative therapy and underwent arthroscopic excision of the distal patellar pole with debridement of the deep proximal patella tendon. At least 3 months postoperatively (range, 3 months-5 years), 8 patients reported no distal patellar pole tenderness (Bassett sign), and 1 patient reported only mild tenderness. Arthroscopic excision of the distal patellar pole with tendon debridement holds promise for the treatment of refractory patellar tendinitis.

  5. Distally based perforator sural flaps for foot and ankle reconstruction

    PubMed Central

    Chang, Shi-Min; Li, Xiao-Hua; Gu, Yu-Dong

    2015-01-01

    Distally based perforator sural flaps from the posterolateral or posteromedial lower leg aspect are initially a neurofasciocutaneous flap that can be transferred reversely to the foot and ankle region with no need to harvest and sacrifice the deep major artery. These flaps are supplied by a perforating artery issued from the deep peroneal artery or the posterior tibial artery, and the chain-linked adipofascial neurovascular axis around the sural/saphenous nerve. It is a versatile and reliable technique for soft-tissue reconstruction of the heel and ankle region with 180-degrees rotation. In this paper, we present its developing history, vascular basis, surgical techniques including flap design and elevation, flap variations in pedicle and component, surgical indications, and illustrative case reports with different perforating vessels as pivot points for foot and ankle coverage. PMID:25893175

  6. Centriole distal appendages promote membrane docking, leading to cilia initiation

    PubMed Central

    Tanos, Barbara E.; Yang, Hui-Ju; Soni, Rajesh; Wang, Won-Jing; Macaluso, Frank P.; Asara, John M.; Tsou, Meng-Fu Bryan

    2013-01-01

    The distal appendages (DAPs) of centrioles have been proposed to anchor cilia to the plasma membrane, but their molecular composition, assembly, and exact function in ciliogenesis remain poorly understood. Using quantitative centrosome proteomics and superresolution microscopy, we identified five DAP components, including one previously described (CEP164), one partially characterized (CEP89 [ccdc123]), and three novel (CEP83 [ccdc41], SCLT1, and FBF1) DAP proteins. Analyses of DAP assembly revealed a hierarchy. CEP83 recruits both SCLT1 and CEP89 to centrioles. Subsequent recruitment of FBF1 and CEP164 is independent of CEP89 but mediated by SCLT1. All five DAP components are essential for ciliogenesis; loss of CEP83 specifically blocks centriole-to-membrane docking. Undocked centrioles fail to recruit TTBK2 or release CP110, the two earliest modifications found on centrioles prior to cilia assembly, revealing centriole-to-membrane docking as a temporal and spatial cue promoting cilia initiation. PMID:23348840

  7. [Implant rehabilitation of distal mandibular atrophy using a blade implant].

    PubMed

    Veron, C; Chanavaz, M

    1997-11-01

    After a brief revision of the anatomy of the posterior mandible and its natural resorption pattern, the ramus plate-form implant would be the implant of choice for the rehabilitation of this region. This "site specific" implant is inserted on the top of the crest and superficially impacted within the residual alveolar bone at the distal segment of the horizontal branch and guided to climb parallel to the anterior aspect of the ascending ramus. Its form and specific dimensions are perfectly compatible with the frequently limited quantity of available bone above the nerve canal in patients with advanced atrophy of the posterior mandible. It provides a predictable abutment for the implant-supported or dento-implant-supported prostheses of the posterior mandible.

  8. Distal interphalangeal joint implant arthroplasty in a musician.

    PubMed

    Schwartz, D A; Peimer, C A

    1998-01-01

    Degenerative joint disease commonly affects the distal interphalangeal (DIP) joints, causing articular destruction and marginal bone formation. Treatment for pain relief and function is most often done through arthrodesis. The case of a 70-year-old concert violinist with left index finger DIP joint osteoarthritis is presented. Arthritis in the involved joint caused pain and deformity and interfered with the patient's ability to play music. Trial arthrodesis with K-wires proved impossible because of the patient's need for continued mobility. Swanson hinge implant arthroplasty was performed on the affected DIP joint. The patient eventually achieved an excellent result and was able to return to playing the violin professionally. Treatment and therapy guidelines are presented.

  9. Sphincter-saving procedures for distal carcinoma of the rectum.

    PubMed Central

    Yeatman, T J; Bland, K I

    1989-01-01

    Methods of sphincter preservation were developed more than a century ago. Combining these techniques with adequate anterior resection has permitted the resurrection of sphincter-saving procedures that are currently being applied in the therapy of cancer at every level of the rectum. Although Miles' abdominoperineal resection still remains the "gold standard" for the treatment of low rectal neoplasms, restorative resection may now be possible with equivalent oncologic disease control and survival. Further, current trends also suggest that the abdominoperineal resection is being used less frequently in the treatment of most rectal cancers and is being replaced with sphincter-preserving techniques that afford excellent functional results. In this review, the pertinent anorectal anatomy, current issues, and sphincter-saving surgical techniques presently available for the treatment of distal cancers of the rectum are presented. PMID:2642688

  10. Distal radial fractures heal by direct woven bone formation

    PubMed Central

    2013-01-01

    Background Descriptions of fracture healing almost exclusively deal with shaft fractures and they often emphasize endochondral bone formation. In reality, most fractures occur in metaphyseal cancellous bone. Apart from a study of vertebral fractures, we have not found any histological description of cancellous bone healing in humans. Patients and methods We studied histological biopsies from the central part of 12 distal radial fractures obtained during surgery 6–28 days after the injury, using routine hematoxylin and eosin staining. Results New bone formation was seen in 6 cases. It was always in the form of fetal-like, disorganized woven bone. It seldom had contact with old trabeculae and appeared to have formed directly in the marrow. Cartilage was scarce or absent. The samples without bone formation showed only necrosis, scar, or old cancellous bone. Interpretation The histology suggests that cells in the midst of the marrow respond to the trauma by direct formation of bone, independently of trabecular surfaces. PMID:23570338

  11. Cutaneous Mycobacterium chelonae infection distal to the arteriovenous fistula.

    PubMed

    Van Ende, Charlotte; Wilmes, Dunja; Lecouvet, Frédéric E; Labriola, Laura; Cuvelier, René; Van Ingelgem, Grégory; Jadoul, Michel

    2016-10-01

    A few single cases of Mycobacterium chelonae skin infection have been reported in haemodialysis patients. We report three additional cases that share peculiar clinical characteristics, pointing to diagnostic clues. All three cases presented as erythematous nodules developing distally to a proximal arteriovenous fistula (AVF). This presentation was identical to that of two published cases. A survey of all Belgian haemodialysis units during the period 2007-11 yields an estimated incidence of ∼0.9/10 000 patient-years. Although the source of M. chelonae remains unclear, this specific clinical presentation should be added to the listing of potential complications of an AVF and should be recognized, as it is fully treatable if diagnosed by culture and tissue biopsy.

  12. Cutaneous Mycobacterium chelonae infection distal to the arteriovenous fistula

    PubMed Central

    Van Ende, Charlotte; Wilmes, Dunja; Lecouvet, Frédéric E.; Labriola, Laura; Cuvelier, René; Van Ingelgem, Grégory; Jadoul, Michel

    2016-01-01

    A few single cases of Mycobacterium chelonae skin infection have been reported in haemodialysis patients. We report three additional cases that share peculiar clinical characteristics, pointing to diagnostic clues. All three cases presented as erythematous nodules developing distally to a proximal arteriovenous fistula (AVF). This presentation was identical to that of two published cases. A survey of all Belgian haemodialysis units during the period 2007–11 yields an estimated incidence of ∼0.9/10 000 patient-years. Although the source of M. chelonae remains unclear, this specific clinical presentation should be added to the listing of potential complications of an AVF and should be recognized, as it is fully treatable if diagnosed by culture and tissue biopsy. PMID:27679721

  13. [Evaluation of surgical repair of distal biceps tendon ruptures].

    PubMed

    Behounek, J; Hrubina, M; Skoták, M; Krumpl, O; Zahálka, M; Dvorák, J; Fucík, M

    2009-02-01

    PURPOSE OF THE STUDY To present the results of surgical repair of ruptures of the distal tendon of the biceps brachii muscle and thus show the adequacy of this treatment. MATERIAL Between 1987 and 2006, 19 patients had surgery for distal biceps tendon rupture. Only one side was affected in each patient. All patients were men between 28 and 69 years (average age, 47.5 years) at the time of injury (surgery). When the patients were evaluated at the end of 2007, 18 patients were included, because one died a year after surgery. METHODS The surgical repair always included a single-incision anatomical reattachment into the radial tuberosity. In 11 patients, a modified Mac Reynolds method with screw and washer fixation was used; in seven patients the insertion was fixed with Mitek anchors and, in one, it was sutured to the adjacent soft tissues. The average follow-up was 7 years (range, 1 to 20.5 years). The patients were evaluated for the cause of injury, their physical activity, age, dominance of the injured arm, surgical procedure and complications. RESULTS In 18 patients surgical repair was done early and, in one, at 16 days after injury. In all of them the tendon was detached from its site of insertion, but never torn. The intra-operative complications included, in one patient, bleeding owing to iatrogenic damage to a branch of the brachial artery, and difficult separation of the tendon due to its previous healed injury in another patient. Early post-operative complications included superficial skin necrosis in one patient and transient neurological deficit of the dorsal brand of the radial nerve and of the lateral cutaneous nerve of the forearm in two and one patient, respectively. The late complications were heterotropic ossification in three patients and screw migration in the one treated by the Mac Reynolds method. Excellent results were recorded in 11 patients (61 %), and good outcomes with a slight restriction of motion or muscle strength not limiting the

  14. Growth after extendible endoprosthetic replacement of the distal femur.

    PubMed

    Cool, W P; Carter, S R; Grimer, R J; Tillman, R M; Walker, P S

    1997-11-01

    We report our results in 24 children with malignant primary bone tumours of the distal femur treated with a Stanmore extendible endoprosthesis (SEER). This consists of a femoral component that can be lengthened, a constrained knee and an uncemented sliding tibial component which crosses the proximal tibial physeal plate perpendicularly. The average age of the patients at diagnosis was ten years and the mean follow-up was 4.7 years (2.5 to 7.9). The mean growth of the affected tibia was 76% (18 to 136) and of the fibula 83% (15 to 750) of the growth of the unaffected limb. Measurement of growth arrest lines showed that the mean growth of the proximal tibial physis on the affected side was 69% (43 to 100) of that of the normal side. The great variability in the growth of the physis cannot yet be explained.

  15. Distal Limb Defects and Aplasia Cutis: Adams-Oliver Syndrome.

    PubMed

    Renfree, Kevin J; Dell, Paul C

    2016-07-01

    Adams-Oliver syndrome is a rare congenital condition that should be considered in persons with terminal transverse limb deficiencies and scalp defects (aplasia cutis congenita). Broad phenotypic variability exists in this condition. In its more severe forms, Adams-Oliver syndrome can involve the cardiovascular system, central nervous system, gastrointestinal tract, and genitourinary system and should require prompt evaluation by appropriate subspecialists. Extremity involvement is typically bilateral and asymmetrical, with lower extremities involved more than upper extremities. Brachydactyly is the most common limb defect, and severity ranges from hypoplastic nails to complete absence of the distal limb. The syndrome has been described as resulting from autosomal dominant and recessive modes of inheritance, but most cases are sporadic. No gene has been identified. Although the exact pathogenic mechanism is unknown, a common hypothesis is that a vascular disturbance occurs in watershed areas, such as cranial vertex and limbs, during fetal development.

  16. Topical agents for idiopathic distal colitis and proctitis.

    PubMed

    Lawrance, Ian Craig

    2011-01-01

    Rectally administered topical agents have demonstrated efficacy in the maintenance of distal colitis (DC) and proctitis and as they are rarely associated with significant blood drug levels, side effects are infrequent. The topical 5-aminosalicylic acid (5-ASA) suppositories and enemas target different regions of the distal colon and are effective for proctitis and DC, respectively. They demonstrate clinical results that are better than oral 5-ASAs and are preferred to topical steroids with better clinical, endoscopic and histological outcomes, without the risk of adrenal suppression. Disease resistant to topical agents, however, can be extremely difficult to manage. The addition of oral 5ASAs, steroids, immunosuppressants and the anti-tumor necrosis factor-α agents may be effective, but can result in significant side effects and not all patients will respond to the therapies. It is for these patients that new and novel therapies are required. Novel topical agents have been proposed for the management of resistant DC. These agents included butyrate, cyclosporine, and nicotine enemas, as well as tacrolimus suppositories, and tacrolimus, ecabet sodium, arsenic, lidocaine, bismuth, rebamipide and thromboxane enemas. While some of these agents appear to demonstrate impressive outcomes, the majority have only been examined in small open-labeled studies. There is thus a desperate need for more randomized double-blinded placebo controlled studies to investigate the clinical utility of these topical therapies. This review summarizes the efficacy of the established topical therapies, and explores the available data on the new and novel topical agents for the management of DC and proctitis.

  17. Contact mechanics of reverse engineered distal humeral hemiarthroplasty implants.

    PubMed

    Willing, Ryan; King, Graham J W; Johnson, James A

    2015-11-26

    Erosion of articular cartilage is a concern following distal humeral hemiarthroplasty, because native cartilage surfaces are placed in contact with stiff metallic implant components, which causes decreases in contact area and increases in contact stresses. Recently, reverse engineered implants have been proposed which are intended to promote more natural contact mechanics by reproducing the native bone or cartilage shape. In this study, finite element modeling is used in order to calculate changes in cartilage contact areas and stresses following distal humeral hemiarthroplasty with commercially available and reverse engineered implant designs. At the ulna, decreases in contact area were -34±3% (p=0.002), -27±1% (p<0.001) and -14±2% (p=0.008) using commercially available, bone reverse engineered and cartilage reverse engineered designs, respectively. Peak contact stresses increased by 461±57% (p=0.008), 387±127% (p=0.229) and 165±16% (p=0.003). At the radius, decreases in contact area were -21±3% (p=0.013), -13±2% (p<0.006) and -6±1% (p=0.020), and peak contact stresses increased by 75±52% (p>0.999), 241±32% (p=0.010) and 61±10% (p=0.021). Between the three different implant designs, the cartilage reverse engineered design yielded the largest contact areas and lowest contact stresses, but was still unable to reproduce the contact mechanics of the native joint. These findings align with a growing body of evidence indicating that although reverse engineered hemiarthroplasty implants can provide small improvements in contact mechanics when compared with commercially available designs, further optimization of shape and material properties is required in order reproduce native joint contact mechanics.

  18. An X-ray template assessment for distal radial fractures

    PubMed Central

    Lindeboom, R.; Oosterkamp, A. E.; Goslings, J. C.

    2007-01-01

    Background The current method for radiological measurements on plain X-rays of distal radius fractures is unreliable. We examined the reproducibility of a new X-ray assessment technique—where the uninjured side is used as a template for the injured side—compared to the conventional assessment technique. Methods X-rays of 30 patients with a unilateral distal radial fracture were included reflecting the prevalence of AO fracture types in clinical practice. Eight experienced observers assessed these X-rays on two separated occasions (2-month interval) using the traditional measurement technique and the template technique. Reproducibility of the X-ray assessments was quantified by intraclass correlations and weighted kappa coefficients. Results The reproducibility of the radial length measurement did not improve nor did the volar angulation measurement. However, marked improvement in reproducibility was observed for the radial inclination measurement, the kappa increased from 0.36 (95 % CI; 0.30–0.41) to 0.49 (95 % CI; 0.43–0.55) in the template technique. As a result, the classification of the reduction results (Lidström score) greatly improved. The overall kappa for the Lidström score improved from 0.37 (95 % CI; 0.31/0.43) to 0.59 (0.52/0.63). Conclusion The assessment technique using the uninjured side as a template for the injured side resulted only in an improved reproducibility of the radial inclination measurement which in turn resulted in an improved classification reproducibility of the reduction results. PMID:17622544

  19. The Unstable Distal Radius Fracture—How Do We Define It? A Systematic Review

    PubMed Central

    Walenkamp, Monique M. J.; Vos, Lara M.; Strackee, Simon D.; Goslings, J. Carel; Schep, Niels W. L.

    2015-01-01

    Background Unstable distal radius fractures are a popular research subject. However, to appreciate the findings of studies that enrolled patients with unstable distal radius fractures, it should be clear how the authors defined an unstable distal radius fracture. Questions In what percentage of studies involving patients with unstable distal radius fractures did the authors define unstable distal radius fracture? What are the most common descriptions of an unstable distal radius fracture? And is there one preferred evidence-based definition for future authors? Methods A systematic search of literature was performed to identify any type of study with the term unstable distal radius fracture. We assessed whether a definition was provided and determined the level of evidence for the most common definitions. Results The search yielded 2,489 citations, of which 479 were included. In 149 studies, it was explicitly stated that patients with unstable distal radius fractures were enrolled. In 54% (81/149) of these studies, the authors defined an unstable distal radius fracture. Overall, we found 143 different definitions. The seven most common definitions were: displacement following adequate reduction; Lafontaine's definition; irreducibility; an AO type C2 fracture; a volarly displaced fracture; Poigenfürst's criteria; and Cooney's criteria. Only Lafontaine's definition originated from a clinical study (level IIIb). Conclusion In only half of the studies involving patients with an unstable distal radius fracture did the authors defined what they considered an unstable distal radius fracture. None of the definitions stood out as the preferred choice. A general consensus definition could help to standardize future research. PMID:26649263

  20. Latent Class Analysis with Distal Outcomes: A Flexible Model-Based Approach

    ERIC Educational Resources Information Center

    Lanza, Stephanie T.; Tan, Xianming; Bray, Bethany C.

    2013-01-01

    Although prediction of class membership from observed variables in latent class analysis is well understood, predicting an observed distal outcome from latent class membership is more complicated. A flexible model-based approach is proposed to empirically derive and summarize the class-dependent density functions of distal outcomes with…

  1. Distal and Proximal Vision: A Multi-Perspective Research in Sociology of Education

    ERIC Educational Resources Information Center

    Giancola, Orazio; Viteritti, Assunta

    2014-01-01

    Drawing inspiration from the research conducted in Italian schools involved in the reform process, the article proposes to investigate two visions in the research on Sociology of Education: one distal and the other proximal. The distal vision is offered by quantitative research nowadays supported by extensive public funding and framed as…

  2. Distal prosody affects learning of novel words in an artificial language.

    PubMed

    Morrill, Tuuli H; McAuley, J Devin; Dilley, Laura C; Zdziarska, Patrycja A; Jones, Katherine B; Sanders, Lisa D

    2015-06-01

    The distal prosodic patterning established at the beginning of an utterance has been shown to influence downstream word segmentation and lexical access. In this study, we investigated whether distal prosody also affects word learning in a novel (artificial) language. Listeners were exposed to syllable sequences in which the embedded words were either congruent or incongruent with the distal prosody of a carrier phrase. Local segmentation cues, including the transitional probabilities between syllables, were held constant. During a test phase, listeners rated the items as either words or nonwords. Consistent with the perceptual grouping of syllables being predicted by distal prosody, congruent items were more likely to be judged as words than were incongruent items. The results provide the first evidence that perceptual grouping affects word learning in an unknown language, demonstrating that distal prosodic effects may be independent of lexical or other language-specific knowledge.

  3. Distal pancreatectomy: en-bloc splenectomy vs spleen-preserving pancreatectomy

    PubMed Central

    Orduña, David; Cesar-Borges, Gleydson; Angel López-Boado, Miguel

    2005-01-01

    Distal pancreatectomy with en-bloc splenectomy has been considered the standard technique for management of benign and malignant pancreatic disorders. However, splenic preservation has recently been advocated. The aim of this study was to review the experiences of distal pancreatectomy using the open or the laparoscopic approach and to critically discuss the need to perform splenectomy. Original articles published in the English literature of peer-reviewed medical journals were selected for detailed analysis. In patients with malignant neoplasms in the body-tail of the pancreas, splenectomy has a negative influence on long-term survival after resection. The incidence of diabetes after spleen-preserving distal pancreatectomy for chronic pancreatitis is less than after en-bloc splenectomy. Spleen salvage eliminates the risk of overwhelming infections. Laparoscopic spleen-preserving distal pancreatectomy is feasible and safe. Laparoscopic spleen-preserving distal pancreatectomy may be preferable for the advantages of a minimally invasive approach. PMID:18333170

  4. Distal polyneuropathy after canine heartworm disease therapy complicated by disseminated intravascular coagulation.

    PubMed

    Dillon, A R; Braund, K G

    1982-08-01

    A 3-year-old male Setter-type dog had a progressive distal sensorimotor polyneuropathy characterized by weakness, bilateral atrophy of distal appendicular musculature, and reduced response to tactile stimuli. The diagnosis of a distal axonopathy was supported by electromyographic findings of fibrillation potentials, positive sharp waves in distal limb muscles, and absence of evoked action potentials, myopathic changes of atrophic angular fibers, and myelinated nerve fiber depletion in distal parts of peripheral nerves. The neuropathy appeared 5 weeks after 38 days of heparin therapy for disseminated intravascular coagulation. The disseminated intravascular coagulation, a complication of thiacetarsamide therapy for heartworm disease, had resolved 40 days after the end of heparin therapy. The cause of the neuropathy was not determined.

  5. Understanding Proximal-Distal Economic Projections of the Benefits of Childhood Preventive Interventions

    PubMed Central

    Slade, Eric P.; Becker, Kimberly D.

    2014-01-01

    This paper discusses the steps and decisions involved in proximal-distal economic modeling, in which social, behavioral, and academic outcomes data for children may be used to inform projections of the economic consequences of interventions. Economic projections based on proximal-distal modeling techniques may be used in cost-benefit analyses when information is unavailable for certain long term outcomes data in adulthood or to build entire cost-benefit analyses. Although examples of proximal-distal economic analyses of preventive interventions exist in policy reports prepared for governmental agencies, such analyses have rarely been completed in conjunction with research trials. The modeling decisions on which these prediction models are based are often opaque to policymakers and other end-users. This paper aims to illuminate some of the key steps and considerations involved in constructing proximal-distal prediction models and to provide examples and suggestions that may help guide future proximal-distal analyses. PMID:24337979

  6. Geochemical patterns in proximal and distal Toba glass

    NASA Astrophysics Data System (ADS)

    Gatti, E.; Achyuthan, H.; Villa, I. M.; Gibbard, P. L.; Oppenheimer, C.

    2012-12-01

    The geochemical components of the Youngest Toba Tuff (YTT) are a direct characteristic of the ashfall that can elucidate magmatic processes and depositional mechanisms of the YTT ultra-distal deposits. We synthesises all readily available geochemical data on glass compositions of the YTT. The dataset includes 69 analyses from the literature and three new analyses, and it reveals considerable variability on in glass composition. The data are used to infer the origins of these geochemical differences in terms of compositional zonation of the magma reservoir, post-depositional alteration, and methodological biases. Magma chamber zonation is found to be the major control on chemical differences in the YTT glass: FeO/TiO2 ratios vary by a factor of ten, reflecting the evolution of the eruption. Post-depositional leaching and weathering is responsible for up to 50% of the differences in mobile element abundances. Na2O/Ka2O and SiO2/Al2O3 ratios are significantly lower in marine depositional sites compared with terrestrial sites. Exceptions to this are ash from the pelagic environment of the Central Indian Ocean Basin (CIOB), whose Na2O/Ka2O ratio is 20% higher than that of other marine sites, and samples from the shallow deltaic and hemipelagic areas of the South China Sea (SCS) and the Arabian Sea, whose SiO2/Al2O3 ratios are similar to those found for terrestrial distal sites. We suggest the water depth in the CIOB and the large flux of terrigenous sediment sourced from the Pearl and Indus Rivers are responsible for the diagenetic differences. Inter-laboratory comparisons indicate that methodological biases are small. The principal findings are: (i) The YTT glass geochemistry at a given site strongly reflects the stage of the eruption (ii) Post-depositional glass alteration is controlled by the depositional environment, i.e., hemipelagic deltaic marine basin, versus pelagic deep ocean basin, versus terrestrial basin, and (iii) All the samples show a minor 'laboratory

  7. Preliminary Experience with a New Total Distal Radioulnar Joint Replacement

    PubMed Central

    Ewald, Timothy J.; Skeete, Kshamata; Moran, Steven L.

    2012-01-01

    This study reports the intermediate-term results of four patients from a series eight patients who have had an insertion of a new complete distal radioulnar joint (DRUJ) prosthesis. A retrospective review was performed for all patients who underwent DRUJ joint replacement with the STABILITY Sigmoid Notch Total DRUJ System between the years of 2003 and 2008. To be included in this report, all patients had to have more than 24 months of follow-up and hand examination by the senior author. From the eight patients with this procedure, four patients met the inclusion criteria. These included one patient with painful posttraumatic arthritis, two patients with failed hemiarthroplasty, and one patient with a failed Sauvé–Kapandji procedure. Mean age at the time of surgery was 42.5 years (range: 35 to 51 years) and mean follow-up was 46 months (range: 36 to 66 months). Preoperative and postoperative assessment included range of motion, grip strength, visual analog pain scale, patient satisfaction, and radiographic evaluation. There was a successful replacement of the DRUJ in all four patients. Final range of motion showed mean pronation of 80 degrees (range: 60 to 90 degrees) and mean supination of 64 degrees (range: 45 to 90 degrees). Final grip strength on the operated extremity was 25.5 kg and averaged 73% of contralateral side. This was an improvement from preoperative grip strength of 14.5 kg visual analog pain scale decreased from 8 to 2.5 following surgery (scale: 1 to 10). Patient satisfaction was 100%. One patient returned to manual labor, one patient returned to office work, and two patients remained off work. Postoperative radiographs depict appropriate alignment of the DRUJ, and there have been no cases of subluxation or dislocation. Implant survival has been 100%. Total DRUJ joint replacement with sigmoid notch resurfacing and distal ulna replacement is an alternative to ulnar head resection in cases of DRUJ arthritis. Total DRUJ arthroplasty with this

  8. A recurrent WARS mutation is a novel cause of autosomal dominant distal hereditary motor neuropathy.

    PubMed

    Tsai, Pei-Chien; Soong, Bing-Wen; Mademan, Inès; Huang, Yen-Hua; Liu, Chia-Rung; Hsiao, Cheng-Tsung; Wu, Hung-Ta; Liu, Tze-Tze; Liu, Yo-Tsen; Tseng, Yen-Ting; Lin, Kon-Ping; Yang, Ueng-Cheng; Chung, Ki Wha; Choi, Byung-Ok; Nicholson, Garth A; Kennerson, Marina L; Chan, Chih-Chiang; De Jonghe, Peter; Cheng, Tzu-Hao; Liao, Yi-Chu; Züchner, Stephan; Baets, Jonathan; Lee, Yi-Chung

    2017-03-22

    Distal hereditary motor neuropathy is a heterogeneous group of inherited neuropathies characterized by distal limb muscle weakness and atrophy. Although at least 15 genes have been implicated in distal hereditary motor neuropathy, the genetic causes remain elusive in many families. To identify an additional causal gene for distal hereditary motor neuropathy, we performed exome sequencing for two affected individuals and two unaffected members in a Taiwanese family with an autosomal dominant distal hereditary motor neuropathy in which mutations in common distal hereditary motor neuropathy-implicated genes had been excluded. The exome sequencing revealed a heterozygous mutation, c.770A > G (p.His257Arg), in the cytoplasmic tryptophanyl-tRNA synthetase (TrpRS) gene (WARS) that co-segregates with the neuropathy in the family. Further analyses of WARS in an additional 79 Taiwanese pedigrees with inherited neuropathies and 163 index cases from Australian, European, and Korean distal hereditary motor neuropathy families identified the same mutation in another Taiwanese distal hereditary motor neuropathy pedigree with different ancestries and one additional Belgian distal hereditary motor neuropathy family of Caucasian origin. Cell transfection studies demonstrated a dominant-negative effect of the p.His257Arg mutation on aminoacylation activity of TrpRS, which subsequently compromised protein synthesis and reduced cell viability. His257Arg TrpRS also inhibited neurite outgrowth and led to neurite degeneration in the neuronal cell lines and rat motor neurons. Further in vitro analyses showed that the WARS mutation could potentiate the angiostatic activities of TrpRS by enhancing its interaction with vascular endothelial-cadherin. Taken together, these findings establish WARS as a gene whose mutations may cause distal hereditary motor neuropathy and alter canonical and non-canonical functions of TrpRS.

  9. Nonunion of distal radius fracture and distal radioulnar joint injury: a modified Sauvé-Kapandji procedure with a cubitus proradius transposition as autograft.

    PubMed

    Villamor, Angel; Rios-Luna, Antonio; Villanueva-Martínez, Manuel; Fahandezh-Saddi, Homid

    2008-12-01

    The Sauvé-Kapandji (SK) procedure is indicated in distal radius nonunion or malunion and distal radioulnar joint (DRUJ) instability. It can also be used to treat the rheumatoid wrist with severe degenerative changes in the DRUJ. The main objective is to allow a pain-free range of movement. We present a patient with rheumatoid arthritis and distal radius nonunion who, after three operations, was treated with the SK procedure. The clinical and radiological results were excellent. A 53-year-old woman diagnosed with rheumatoid arthritis fell on her forearm at home 2 years ago. Examination at an outpatient clinic revealed a distal radius fracture classified as type V according to the Frykman classification. She had been operated three times with open reduction internal fixation using a plate, screws, and bone allograft. She came to our institution with a distal radius nonunion, positive post-traumatic ulnar variance, and ulnar nerve paresis. The range of movements was 20 degrees -10 degrees flexion-extension and 40 degrees -30 degrees pronation-supination, and she needed daily fentanyl. We performed a modified SK procedure with an autologous iliac crest bone graft and ulnar bone graft from the osteotomy area (cubitus proradius), bone morphogenetic protein, and a low profile distal radius plate. After 1 year of follow-up, the distal radius fracture has healed and the wrist is pain-free with a complete range of movement in flexion-extension and pronation-supination. The main indication for the SK procedure is post-traumatic positive ulnar variance and associated ulnocarpal impaction. The cubitus proradius bone graft transposition is an interesting technical note that makes this case a challenge for skilled orthopedic hand surgeons.

  10. Biomechanical analysis of distal radius fractures using intramedullary Kirschner wires.

    PubMed

    Tsai, Wen-Chi; Lin, Shang-Chih; Hsiao, Chun-Ching; Lu, Tung-Wu; Chao, Ching-Kong; Liu, Hwa-Chang

    2009-03-01

    Colles's fracture is the most common type of distal radius fracture. Surgically, it remains a challenge to restore radial height and volar tilt in order to regain optimal wrist function. Ulson's procedure provides a dynamic effect on fixing fractured fragments and restoring joint function using two wires. However, the biomechanical influences of bone and wire remain critical issues for fracture reduction and bone union in Ulson's procedure. Based on elastic beam and foundation theory, this study formulated a closed-form mathematical model to investigate the effects of bone and wire parameters on wire deflection and bony reaction. The wire deflection and bony reaction were chosen as the indices of wrist stability and reduction within the post-operative period. The predicted results showed that greater bone strength, higher wire stiffness, and longer wire contact length provide a more stable wire-bone construct, thus facilitating fracture reduction and bone union. The wire stiffness had a much more significant effect on the construct stability compared with bone quality and contact length. In terms of entry point and insertion angle, surgical planning for the contact length was more important than bony quality for stabilizing the whole wire-bone construct.

  11. Evaluation of Associated Carpal Bone Fractures in Distal Radial Fractures

    PubMed Central

    Heo, Youn Moo; Kim, Sang Bum; Yi, Jin Woong; Park, Cheol Yong; Yoon, Jeong Yong; Kim, Doo Hyun

    2013-01-01

    Background The purpose of this study was to investigate the frequency and distribution of associated carpal bone fractures (CBFs) in distal radial fractures (DRFs). Methods Three hundred and thirteen patients who underwent surgical treatment for DRFs between March 2007 and January 2010 were reviewed retrospectively. In this study, 223 patients who had preoperative computed tomography (CT) were included. We investigated the frequency and distribution of associated CBFs on CT scans. The relationship between the frequency of associated CBFs and patient factors such as age, gender, body mass index, and the mechanism of injury was assessed. Results CBFs were complicated in 46 of 223 DRFs (20.9%). The distribution of CBFs was 23 cases in the triquetrum, 16 in the lunate, 12 in the scaphoid, five in the hamate, and four in the pisiform. Among the 46 cases, a fracture of one carpal bone occurred in 36 cases, two in seven cases, three in two cases, and four in one case. In 10 of the 46 cases, associated CBFs occurred in more than two carpal bones. No significant differences were observed for age, sex, body mass index, or the mechanism of injury between patients with DRFs and CBFs and those without CBFs. Conclusions Because CBFs that mainly occur in the proximal carpal row are complicated in DRFs at a relatively high frequency, assessment of carpal bones using CT scans is beneficial. PMID:23730472

  12. Internal fixators: a safe option for managing distal femur fractures?

    PubMed Central

    Batista, Bruno Bellaguarda; Salim, Rodrigo; Paccola, Cleber Antonio Jansen; Kfuri, Mauricio

    2014-01-01

    OBJECTIVE: Evaluate safety and reliability of internal fixator for the treatment of intra-articular and periarticular distal femur fractures. METHODS: Retrospective data evaluation of 28 patients with 29 fractures fixed with internal fixator was performed. There was a predominance of male patients (53.5%), with 52% of open wound fractures, 76% of AO33C type fractures, and a mean follow up of 21.3 months. Time of fracture healing, mechanical axis deviation, rate of infection and postoperative complications were registered. RESULTS: Healing rate was 93% in this sample, with an average time of 5.5 months. Twenty-seven percent of patients ended up with mechanical axis deviation, mostly resulting from poor primary intra-operative reduction. There were two cases of implant loosening; two implant breakage, and three patients presented stiff knee. No case of infection was observed. Healing rate in this study was comparable with current literature; there was a high degree of angular deviation, especially in the coronal plane. CONCLUSION: Internal fixators are a breakthrough in the treatment of knee fractures, but its use does not preclude application of principles of anatomical articular reduction and mechanical axis restoration. Level of Evidence II, Retrospective Study. PMID:25061424

  13. Fluid collection after distal pancreatectomy: a frequent finding

    PubMed Central

    Tjaden, Christin; Hinz, Ulf; Hassenpflug, Matthias; Fritz, Franziska; Fritz, Stefan; Grenacher, Lars; Büchler, Markus W.; Hackert, Thilo

    2015-01-01

    Background Fluid collections (FC) at the resection margin of the pancreatic stump after distal pancreatectomy (DP) are common radiological findings in follow-up scans. No recommendations exist regarding the management of such findings. The aim was to characterise incidence, risk factors, clinical impact and therapy of FC. Method Data of 209 patients who underwent DP between 07/2009 and 06/2011 were prospectively collected and analysed, regarding follow-up CT or MRI scan findings of FC at the resection margin. FC was defined as a cyst-like lesion >1 cm in diameter. Results A follow-up with at least two cross-sectional images was available in 159/209 patients. In the first postoperative control, 68 patients showed an FC (43%). FC size was classified as <5 cm (n = 38 pat.), 5–10 cm (n = 24 pat.) and >10 cm (n = 6 pat.). 20 patients (30%) showed clinical symptoms. Six patients (9%) required specific treatment, all other FC showed spontaneous regression. No correlation with stump closure techniques or preceding postoperative pancreatic fistula was found (4/68 patients, 6%). Multivariate analysis revealed standard resections as the only significant factor for FC. Conclusions FCs at the resection margin after DP are frequent and harmless findings. Therapeutic interventions are required in only 9% of all FC patients. PMID:26776849

  14. Biomechanical study of different plate configurations for distal humerus osteosynthesis.

    PubMed

    Bogataj, M; Kosel, F; Norris, R; Krkovic, M; Brojan, M

    2015-05-01

    Fractures of the distal humerus are most commonly fixed by open reduction and internal fixation, using plates and screws, either in a locking or in a non-locking construct. Three different plating systems are commonly used in practice. The most important differences between them are in plate orientation, which affects both the rigidity of the osteosynthesis and invasiveness of the surgical procedure. Unfortunately, there is no common agreement between surgeons about which plate configuration brings the best clinical outcome. In this study, we investigate the theoretical rigidity of plate osteosyntheses considering two types of AO/ASIF configurations (90° angle between plates), Mayo clinic (Acumed) configuration (180° between plates) and dorsal fixation of both plates. We also compared the results for cases with and without contact between the bone fragments. In the case of no bone contact, the Mayo clinic plate configuration is found to be the most rigid, followed by both AO/ASIF plate configurations, and the least rigid system is the Korosec plate configuration. On the other hand, no significant differences between all types of fixation configurations are found in cases with contact in-between the bone fragments. Our findings show that this contact is very important and can compensate for the lack of load carrying capacity of the implants. This could therefore incite other implant fixation solutions, leading to less invasive surgical procedures and consequently improved clinical outcome.

  15. Current status in remnant gastric cancer after distal gastrectomy.

    PubMed

    Ohira, Masaichi; Toyokawa, Takahiro; Sakurai, Katsunobu; Kubo, Naoshi; Tanaka, Hiroaki; Muguruma, Kazuya; Yashiro, Masakazu; Onoda, Naoyoshi; Hirakawa, Kosei

    2016-02-28

    Remnant gastric cancer (RGC) and gastric stump cancer after distal gastrectomy (DG) are recognized as the same clinical entity. In this review, the current knowledges as well as the non-settled issues of RGC are presented. Duodenogastric reflux and denervation of the gastric mucosa are considered as the two main factors responsible for the development of RGC after benign disease. On the other hand, some precancerous circumstances which already have existed at the time of initial surgery, such as atrophic gastritis and intestinal metaplasia, are the main factors associated with RGC after gastric cancer. Although eradication of Helicobacter pylori (H. pylori) in remnant stomach is promising, it is still uncertain whether it can reduce the risk of carcinogenesis. Periodic endoscopic surveillance after DG was reported useful in detecting RGC at an early stage, which offers a chance to undergo minimally invasive endoscopic treatment or laparoscopic surgery and leads to an improved prognosis in RGC patients. Future challenges may be expected to elucidate the benefit of eradication of H. pylori in the remnant stomach if it could reduce the risk for RGC, to build an optimal endoscopic surveillance strategy after DG by stratifying the risk for development of RGC, and to develop a specific staging system for RGC for the standardization of the treatment by prospecting the prognosis.

  16. Current status in remnant gastric cancer after distal gastrectomy

    PubMed Central

    Ohira, Masaichi; Toyokawa, Takahiro; Sakurai, Katsunobu; Kubo, Naoshi; Tanaka, Hiroaki; Muguruma, Kazuya; Yashiro, Masakazu; Onoda, Naoyoshi; Hirakawa, Kosei

    2016-01-01

    Remnant gastric cancer (RGC) and gastric stump cancer after distal gastrectomy (DG) are recognized as the same clinical entity. In this review, the current knowledges as well as the non-settled issues of RGC are presented. Duodenogastric reflux and denervation of the gastric mucosa are considered as the two main factors responsible for the development of RGC after benign disease. On the other hand, some precancerous circumstances which already have existed at the time of initial surgery, such as atrophic gastritis and intestinal metaplasia, are the main factors associated with RGC after gastric cancer. Although eradication of Helicobacter pylori (H. pylori) in remnant stomach is promising, it is still uncertain whether it can reduce the risk of carcinogenesis. Periodic endoscopic surveillance after DG was reported useful in detecting RGC at an early stage, which offers a chance to undergo minimally invasive endoscopic treatment or laparoscopic surgery and leads to an improved prognosis in RGC patients. Future challenges may be expected to elucidate the benefit of eradication of H. pylori in the remnant stomach if it could reduce the risk for RGC, to build an optimal endoscopic surveillance strategy after DG by stratifying the risk for development of RGC, and to develop a specific staging system for RGC for the standardization of the treatment by prospecting the prognosis. PMID:26937131

  17. Histology of a Harris line in a human distal tibia.

    PubMed

    Miszkiewicz, Justyna J

    2015-07-01

    Identification and diagnosis of Harris lines (HLs) is usually achieved using radiography. To date, histological methods have been mainly implemented in research exploring the underlying processes of HL deposition using longitudinal sections taken from animal bone. Here, a new insight into HL formation is provided following transverse histological sectioning in a human specimen. A distinct HL was identified macroscopically, and from a radiograph, in a left distal tibia taken from an adult human male. Transverse sections were taken through the HL, and also from trabeculae immediately superior and inferior to the HL. Thin sections were produced following standard histological procedures. Micrographs were captured using a digital microscope camera. Trabeculae immediately superior and inferior to the HL displayed no indication of abnormal growth, exhibiting abundant osteocyte lacunae and a lamellar structure. However, the micro-anatomy of the HL was characterised by the following three main features: (1) non-lamellar appearance, (2) a complete lack of osteocyte lacunae, and (3) presence of irregularly distributed tubular structures. These three histological features indicate a specific process of bone deposition, implying that trapping of osteoblasts may not take place during HL formation. Pictorial and descriptive records of HL histology are provided, aiding current understanding about the nature of HL, its identification from histology, and serving as a reference point for future comparative research.

  18. Photogrammetric analysis of the articular surface of the distal radius.

    PubMed

    Ege, A; Seker, D Z; Tuncay, I; Duran, Z

    2004-01-01

    Three-dimensional measurements made using photogrammetry have recently gained popularity with the development of real-time detection facilities and up-to-date equipment. The modelling of human bones presents a particular challenge as the measurements required are difficult to obtain, especially from uneven surfaces. In this study, the articular surfaces of 12 radius bones were evaluated using photogrammetry to obtain three-dimensional coordinates of certain points. Morphometric characteristics of the digital topography of the articular surface were analysed using three-dimensional data from more than 200 points for each specimen. The coronal plane curve, from the tip of the styloid process to the centre of the distal radioulnar articular notch, was found to be similar to the fourth degree polynomial function. A mathematical expression representing the sagittal curve passing through scapholunate border could not be found. Close-range photogrammetry is a safe and precise technique that can provide reliable, reproducible and accurate data for evaluating complex morphological surfaces.

  19. Distal and variably proximal causes: education, obesity, and health.

    PubMed

    Schafer, Markus H; Ferraro, Kenneth F

    2011-11-01

    Medical sociologists hold that social conditions generate disparities across a host of health conditions through exposure to a variety of more proximate risk factors. Though distal and proximal causes jointly influence disease, the nature of risk accumulation may differ appreciably by the link of a proximal cause to the outcome in question. This paper employs a representative sample of over 3000 American older adults to examine whether position in the educational gradient amplifies the effect of obesity on two health outcomes. Results indicate that educational inequalities amplify the effect of high body mass index on disability (unstandardized coefficients across education groups range from -.05 [ns] to .26 [p < .01] among overweight respondents yet reach .17 [ns] to .73 [p < .001] among severely obese adults), but fail to amplify the consequences of severe obesity in the case of C-reactive protein (CRP) levels. Instead, educational gradients in CRP are most pronounced at lower levels of body mass. Sex-specific analyses further clarify these patterns, as the connections between CRP and body mass are particularly strong among women. We conclude that risk accumulation processes differ based on the proximity of causes to the health outcome under examination.

  20. Attempts to prevent postoperative pancreatic fistula after distal pancreatectomy.

    PubMed

    Miyasaka, Yoshihiro; Mori, Yasuhisa; Nakata, Kohei; Ohtsuka, Takao; Nakamura, Masafumi

    2017-04-01

    Postoperative pancreatic fistula (POPF) is the most frequent and serious complication after distal pancreatectomy (DP) and often leads to other postoperative complications. Numerous studies have been conducted to clarify the risk factors for POPF after DP, and to also determine effective prophylactic treatments. In this article, we review the current evidence on the risk factors for POPF after DP, and also provide new evidence to support the currently implemented prophylactic measures against POPF after DP. The patient-related and surgery-related risk factors and risk factors specific to staplers are discussed. Several studies have suggested that a thick pancreas is a risk factor for POPF using a stapler and that a higher stapler height or pancreatoenteric anastomosis might be useful for preventing POPF when transecting a thick pancreas. Various methods, such as stapler closure, procedures that may be performed in addition to stapler closure, pancreatoenteric anastomosis, pancreatic transection devices, laparoscopic surgery, pancreatic stenting, stump coverage, and somatostatin analogs, have been tested and in comparison with conventional procedures in case-control studies and randomized, controlled trials. Although some studies have shown the superiority of these methods to the conventional procedures, a consensus on precautionary measures that can be taken against POPF remains to be established. Further investigation is necessary to develop a reliable strategy for preventing POPF and to improve the outcomes of patients after DP.

  1. Allograft selection for distal femur through cutting contour registration.

    PubMed

    Qiu, Lei; Zhang, Yu; Zhang, Qing; Xu, Lihui; Niu, Xiaohui; Zhang, Li

    2016-12-01

    Allograft reconstruction is an acceptable procedure for the recovery of normal anatomy after the bone tumor resection. During the past few years, several automated methods have been proposed to select the best anatomically matching allograft from the virtual donor bone bank. The surface-based automated method uses the contralateral healthy bone to obtain the normal surface shape of the diseased bone, which could achieve good matching of the defect and the selected allograft. However, the surface-based method focuses on the matching of the whole bone so that the matching of the contact surface between the allograft and the recipient bone may not be optimal. To deal with the above problem, we propose a cutting contour based method for the allograft selection. Cutting contour from the recipient bone could reflect the structural information of the defect and is seldom influenced by tumor. Thus the cutting contour can be used as the matching template to find the optimal alignment of the recipient bone and the allograft. The proposed method is validated using the data of distal femurs where bone transplantation is commonly performed. Experimental results show that the proposed method generally outperforms the surface-based method within modest extra time. Overall, our contour-based method is an effective complementary technique for allograft selection in the virtual bone bank.

  2. Operative timing and patient survival following distal splenorenal shunt.

    PubMed

    Pomerantz, R A; Eckhauser, F E; Knol, J A; Guirre, K; Raper, S E; Turcotte, J G

    1989-06-01

    The importance of "operative timing" in cirrhotic patients with variceal hemorrhage is often underemphasized. To evaluate the effects of immediate versus delayed selective portasystemic decompression on hepatic function, operative mortality, and long-term patient survival, we reviewed the records of 77 patients who underwent distal splenorenal shunts (DSRS) over a 14-year period. A hepatic risk status score was calculated at the time of the index bleed (HRS1) or presentation and again just prior to operation (HRS2). Variables analyzed included age, sex, prior bleeding episodes, time from index bleed to operation, transfusion requirements, and etiology of cirrhosis. Operative mortality rates for immediate versus delayed DSRS were 46.2 per cent and 17 per cent, respectively. HRS improved significantly in elective DSRS patients from 1.46 to 1.30. Predictors of HRS2 included HRS1 and time in days from the index bleed to operation. The most important predictor of early survival for all patients after elective DSRS was the HRS2; however, for patients who underwent elective DSRS and survived, HRS1 was a better predictor of length of survival than HRS2. No other variable analyzed accurately predicted survival. We conclude that HRS can be expected to improve with supportive inhospital therapy; improved HRS at the time of operation is associated with decreased operative mortality; and the extent of liver disease as determined by HRS1 appears to be the chief determinant of long-term patient survival.

  3. In vivo studies of biotin absorption in distal rat intestine

    SciTech Connect

    Bowman, B.B.; Rosenberg, I.H.

    1986-03-01

    The authors have extended their previous studies of biotin absorption in rat proximal jejunum (PJ) to examine biotin absorptive capacity of rat ileum (I) and proximal colon (PC) using in vivo intestinal loop technique. Intestinal loops (2.5 cm) were filled with 0.3 ml of solution containing (/sup 3/H)-biotin and (/sup 14/C)-inulin in phosphate buffer, pH 6.5. Biotin absorption was determined on the basis of luminal biotin disappearance after correction for inulin recovery and averaged (pmol/loop-10 min; X +/- SEM). In related experiments, 5-cm loops of PJ, distal I (DI), or PC were filled with 0.5 ml of solution of similar composition (1.0 ..mu..M biotin). The abdominal cavity was closed and the rats were allowed to recover from anesthesia, then sacrificed 3 hr after injection. Biotin absorption averaged 96.2% (PJ), 93.2% (DI), and 25.8% (PC) of the dose administered. These differences were reflected in the radioactive biotin content of plasma and intestinal loop, kidney, and liver. These data demonstrate significant biotin absorption in rat DI and PC, as required if the intestinal microflora are to be considered as a source of biotin for the host.

  4. AO Distal Radius Fracture Classification: Global Perspective on Observer Agreement.

    PubMed

    Jayakumar, Prakash; Teunis, Teun; Giménez, Beatriz Bravo; Verstreken, Frederik; Di Mascio, Livio; Jupiter, Jesse B

    2017-02-01

    Background The primary objective of this study was to test interobserver reliability when classifying fractures by consensus by AO types and groups among a large international group of surgeons. Secondarily, we assessed the difference in inter- and intraobserver agreement of the AO classification in relation to geographical location, level of training, and subspecialty. Methods A randomized set of radiographic and computed tomographic images from a consecutive series of 96 distal radius fractures (DRFs), treated between October 2010 and April 2013, was classified using an electronic web-based portal by an invited group of participants on two occasions. Results Interobserver reliability was substantial when classifying AO type A fractures but fair and moderate for type B and C fractures, respectively. No difference was observed by location, except for an apparent difference between participants from India and Australia classifying type B fractures. No statistically significant associations were observed comparing interobserver agreement by level of training and no differences were shown comparing subspecialties. Intra-rater reproducibility was "substantial" for fracture types and "fair" for fracture groups with no difference accounting for location, training level, or specialty. Conclusion Improved definition of reliability and reproducibility of this classification may be achieved using large international groups of raters, empowering decision making on which system to utilize. Level of Evidence Level III.

  5. Mechanisms and Management of Diabetic Painful Distal Symmetrical Polyneuropathy

    PubMed Central

    Tesfaye, Solomon; Boulton, Andrew J.M.; Dickenson, Anthony H.

    2013-01-01

    Although a number of the diabetic neuropathies may result in painful symptomatology, this review focuses on the most common: chronic sensorimotor distal symmetrical polyneuropathy (DSPN). It is estimated that 15–20% of diabetic patients may have painful DSPN, but not all of these will require therapy. In practice, the diagnosis of DSPN is a clinical one, whereas for longitudinal studies and clinical trials, quantitative sensory testing and electrophysiological assessment are usually necessary. A number of simple numeric rating scales are available to assess the frequency and severity of neuropathic pain. Although the exact pathophysiological processes that result in diabetic neuropathic pain remain enigmatic, both peripheral and central mechanisms have been implicated, and extend from altered channel function in peripheral nerve through enhanced spinal processing and changes in many higher centers. A number of pharmacological agents have proven efficacy in painful DSPN, but all are prone to side effects, and none impact the underlying pathophysiological abnormalities because they are only symptomatic therapy. The two first-line therapies approved by regulatory authorities for painful neuropathy are duloxetine and pregabalin. α-Lipoic acid, an antioxidant and pathogenic therapy, has evidence of efficacy but is not licensed in the U.S. and several European countries. All patients with DSPN are at increased risk of foot ulceration and require foot care, education, and if possible, regular podiatry assessment. PMID:23970715

  6. Endovascular pseudoaneurysm repair after distal pancreatectomy with celiac axis resection

    PubMed Central

    Sumiyoshi, Tatsuaki; Shima, Yasuo; Noda, Yoshihiro; Hosoki, Shingo; Hata, Yasuhiro; Okabayashi, Takehiro; Kozuki, Akihito; Nakamura, Toshio

    2013-01-01

    Erosive hemorrhage due to pseudoaneurysm is one of the most life-threatening complications after pancreatectomy. Here, we report an extremely rare case of rupture of a pseudoaneurysm of the common hepatic artery (CHA) stump that developed after distal pancreatectomy with en block celiac axis resection (DP-CAR), and was successfully treated through covered stent placement. The patient is a 66-year-old woman who underwent DP-CAR after adjuvant chemoradiotherapy for locally advanced pancreatic body cancer. She developed an intra-abdominal abscess around the remnant pancreas head 31 d after the surgery, and computed tomography (CT) showed an occluded portal vein due to the spreading inflammation around the abscess. Her general condition improved after CT-guided drainage of the abscess. However, 19 d later, she presented with melena, and CT showed a pseudoaneurysm arising from the CHA stump. Because the CHA had been resected during the DP-CAR, this artery could not be used as the access route for endovascular treatment, and instead, we placed a covered stent via the inferior pancreaticoduodenal artery originating from the superior mesenteric artery. After stent placement, cessation of bleeding and anterograde hepatic artery flow were confirmed, and the patient recovered well without any further complications. CT angiography at the 6-mo follow-up indicated the patency of the covered stent with sustained hepatic artery flow. To our knowledge, this is the first reported case of endovascular repair of a pseudoaneurysm that developed after DP-CAR. PMID:24363537

  7. Transcriptionally Regulated Cell Adhesion Network Dictates Distal Tip Cell Directionality

    PubMed Central

    Wong, Ming-Ching; Kennedy, William P.; Schwarzbauer, Jean E.

    2015-01-01

    Background The mechanisms that govern directional changes in cell migration are poorly understood. The migratory paths of two distal tip cells (DTC) determine the U-shape of the C. elegans hermaphroditic gonad. The morphogenesis of this organ provides a model system to identify genes necessary for the DTCs to execute two stereotyped turns. Results Using candidate genes for RNAi knockdown in a DTC-specific strain, we identified two transcriptional regulators required for DTC turning: cbp-1, the CBP/p300 transcriptional coactivator homologue, and let-607, a CREBH transcription factor homologue. Further screening of potential target genes uncovered a network of integrin adhesion-related genes that have roles in turning and are dependent on cbp-1 and let-607 for expression. These genes include src-1/Src kinase, tln-1/talin, pat-2/α integrin and nmy-2, a nonmuscle myosin heavy chain. Conclusions Transcriptional regulation by means of cbp-1 and let-607 is crucial for determining directional changes during DTC migration. These regulators coordinate a gene network that is necessary for integrin-mediated adhesion. Overall, these results suggest that directional changes in cell migration rely on the precise gene regulation of adhesion. PMID:24811939

  8. Normative data for distal line bisection and baking tray task.

    PubMed

    Facchin, Alessio; Beschin, Nicoletta; Pisano, Alessia; Reverberi, Cristina

    2016-09-01

    Line bisection is one of the tests used to diagnose unilateral spatial neglect (USN). Despite its wide application, no procedure or norms were available for the distal variant when the task was performed at distance with a laser pointer. Furthermore, the baking tray task was an ecological test aimed at diagnosing USN in a more natural context. The aim of this study was to collect normative values for these two tests in an Italian population. We recruited a sample of 191 healthy subjects with ages ranging from 20 to 89 years. They performed line bisection with a laser pointer on three different line lengths (1, 1.5, and 2 m) at a distance of 3 m. After this task, the subjects performed the baking tray task and a second repetition of line bisection to test the reliability of measurement. Multiple regression analysis revealed no significant effects of demographic variables on the performance of both tests. Normative cut-off values for the two tests were developed using non-parametric tolerance intervals. The results formed the basis for clinical use of these two tools for assessing lateralized performance of patients with brain injury and for diagnosing USN.

  9. Neurofibromatosis Type 2 Presenting with Oculomotor Ophthalmoplegia and Distal Myopathy

    PubMed Central

    Tevaraj, Jessica Mani Penny; Mohd Noor, Raja Azmi; Yaakub, Azhany

    2016-01-01

    Neurofibromatosis type 2 usually presents with bilateral acoustic schwannomas. We highlight the rare presentation of neurofibromatosis initially involving third nerve. A 23-year-old Malay female presented with left eye drooping of the upper lid and limitation of upward movement for 8 years. It was associated with right-sided body weakness, change in voice, and hearing disturbance in the right ear for the past 2 years. On examination, there was mild ptosis and limitation of movement superiorly in the left eye. Both eyes had posterior subcapsular cataract. Fundoscopy showed generalised optic disc swelling in both eyes. She also had palsy of the right vocal cord, as well as the third and eighth nerve. There was wasting of the distal muscles of her right hand, with right-sided decreased muscle power. Pedunculated cutaneous lesions were noted over her body and scalp. MRI revealed bilateral acoustic and trigeminal schwannomas with multiple extra-axial lesions and intradural extramedullary nodules. Patient was diagnosed with neurofibromatosis type 2 and planned for craniotomy and tumour debulking, but she declined treatment. Neurofibromatosis type 2 may uncommonly present with isolated ophthalmoplegia, so a thorough physical examination and a high index of suspicion are required to avoid missing this condition. PMID:27738538

  10. Mediastinal migration of distal occipito-thoracic instrumentation

    PubMed Central

    Joseph, Vivek; Al Jahwari, Ahmed S.

    2007-01-01

    We present the occurrence and management of mediastinal migration of the distal aspect of a posterior occipito-thoracic screw–rod construct. No similar occurrence was found in the literature. This event occurred following an emergency tracheotomy (requiring neck hyperextension) in a patient with severe rheumatoid arthritis, who had previously undergone decompression and an Occiput-T2 instrumented fusion for cranio-cervical and sub-axial cervical spine instability. Imaging showed fracture-subluxation of T1/2 and T2/3 with the bilateral C7, T1 and T2 screws in the mediastinum causing tracheal and esophageal compression. Removal of the instrumentation, decompression (T2 corpectomy) and construct revision down to T10 was safely performed from a posterior approach. Severe osteoporosis, some pre-existing screw loosening and hyperextension of the neck were the predisposing factors of this near catastrophic event. By staying directly posterior to the rod and following the fibrous tract already created, the instrumentation was safely removed from the mediastinum. PMID:18000689

  11. Presence of Two Distal and One Mesial Root Canals in Mandibular Second Molars: Report of Four Cases

    PubMed Central

    Parirokh, Masoud; V. Abbott, Paul; Yosefi, Mohammad Hosein; Hosseini, Hamid Reza

    2014-01-01

    Most mandibular second molars have one and two canals in distal and mesial roots, respectively. This report represents four cases of mandibular second molars with a single mesial and two distal root canals with two different canal configurations. After access cavity preparation, two teeth had one distal and two mesial orifices, whereas in the two other teeth one mesial and two distal orifices were found. In the teeth with two mesial canal orifices, the distal root canal and one of root canals with a mesial orifice joined together in the apical part of the root, whereas in the two other teeth with one mesial and two distal canal orifices, three separate canals each with a different apical foramen were detected. Dental practitioners should be aware that despite higher prevalence of one distal and two mesial root canals, the mandibular second molars may also have one mesial and two distal root canals. PMID:25031600

  12. Bucket and straw technique to facilitate passage of a ventriculoperitoneal shunt through the distal tunneling sheath.

    PubMed

    Downes, Angela E; Vandergrift, William A; Beckman, Joshua M; Truong, Devon; Tuite, Gerald F

    2014-12-01

    Placement of a ventriculoperitoneal shunt (VPS) is a procedure comprising many small steps. Difficulties and delays can arise when passing the distal shunt tubing down the distal tunneling sheath during surgery. The authors of this report describe a simple technique for quickly passing the distal catheter of a VPS through the tunneler sheath, whereby the sheath is used as a fluid tube to allow the distal catheter to be drawn through the fluid tube under suction pressure. The plastic sheath that surrounds the shunt tunneler device is used as a fluid tube, or "straw," with the proximal aperture submerged into a bucket of sterile irrigation liquid containing the distal catheter. Suction pressure is placed against the distal aperture of the tunneler, and the shunt catheter is quickly drawn through the sheath. No special equipment is required. In time trials, the bucket and straw technique took an average of 0.43 seconds, whereas traditional passage methods took 32.3 seconds. The "bucket and straw" method for passing distal shunt tubing through the tunneler sheath is a technique that increases surgical efficiency and reduces manual contact with shunt hardware.

  13. Immediate changes in the mandibular dentition after maxillary molar distalization using headgear

    PubMed Central

    Kang, Sung-Ja; Kim, Hyun-Hee; Hwang, Hyeon-Shik

    2017-01-01

    The purpose of this study was to investigate immediate changes in the mandibular dentition after maxillary molar distalization using headgear in non-growing patients. Sixteen patients (mean age, 18.9 ± 2.0 years) with Class II molar relationship and crowding were included in the present study. To correct the molar relationship, headgear was used for maxillary molar distalization. Cone-beam computed tomography-generated half-cephalograms (CG Cephs) and dental casts were used to evaluate dental changes for each subject before and immediately after molar distalization using headgear. The mean duration that subjects wore the headgear was 6.3 months. CG Cephs showed that the first maxillary molars were distalized 4.2 ± 1.6 mm with 9.7° ± 6.1° of distal angulation. The intercanine, interpremolar, and intermolar widths of the mandible increased after maxillary molar distalization. The present study's results suggest that maxillary molar distalization using headgear induces a spontaneous response in the untreated mandibular dentition of non-growing patients. PMID:28337423

  14. [Primary culture and functional identification of distal pulmonary artery smooth muscle cells in mice].

    PubMed

    Li, M C; Chen, Y Q; Zhang, C T; Jiang, Q; Lu, W J; Wang, J

    2017-02-12

    Objective: To establish a method of isolation and primary culture of mice distal pulmonary artery smooth muscle cells (PASMCs) and identify the functional properties. Methods: PASMCs were harvested from the distal pulmonary artery (PA) tissue of mice by enzymatic digestion of collagenaseⅠand papain; and the growth characteristics were observed under inverted microscope and identified by Immunofluorescence technique. Effects on the intracellular calcium ion concentration of distal PASMCs were detected by Fura-2-AM fluorescent probe tracer under a fluorescence microscope in Krebs solution containing clopiazonic acid (CPA) and nifedipin (Nif). Results: PASMCs density reached approximately to 80% in a typical valley-peak-like shape after 6 days. Cell α-smooth muscle actin (α-SMA) immunofluorescence identified that 95% of the cultured cells were PASMCs. More than 95% PASMCs responded well to calcium-potassium Krebs solution (potassium ion concentration of 60 mmol/L) and showed a rapid increase in basal [Ca(2+) ](i) after 1 minute's perfusion (Δ[Ca(2+) ](i)>50), which demonstrated that the voltage-dependent calcium channels (VDCC) of distal PASMCs were in good function; after the perfusion of calcium Krebs, calcium-free/calcium-Krebs containing CPA and Nif, distal PASMCs showed two typical peaks, indicated the full function of store-operated calcium channel (SOCC) in distal PASMCs. Conclusion: This experiment successfully established a stable and reliable mice distal PASMCs model and the study of pulmonary vascular diseases could benefit from its higher purity and better functional condition.

  15. Outcomes Following Operative Treatment of open Fractures of the Distal Radius: A Case Control Study

    PubMed Central

    MacKay, Brendan J; Montero, Nicole; Paksima, Nader; Egol, Kenneth A

    2013-01-01

    Purpose To report radiographic, clinical, and patient-based functional outcomes following contemporary operative treatment of patients who sustained an open distal radius fracture and compare them to a similar group of patients treated operatively for closed distal radius fractures. Methods Over five years, 601 patients with a distal radius fracture presented to our academic medical center, including one Level 1 trauma hospital, and were prospectively enrolled in an upper extremity trauma database. Patients with open distal radius fractures underwent irrigation, debridement, and operative fixation within 24 hours of presentation. Closed distal radius fractures requiring operative fixation were treated electively. Retrospective review of the database identified eighteen open fractures of the distal radius (11 type I, 6 type II, 1 type IIIa). The open fracture patients were individually matched with eighteen closed distal radius fracture patients who underwent surgical fixation based on age, sex, injury to dominant extremity, fracture pattern, and method of fracture fixation. Clinical, radiographic, patient- based functional outcomes, and complications were recorded at routine postoperative intervals. Results Follow-up was greater than 77% in both groups at all time points. The open and closed groups were similar in regards to age, gender, BMI, race, tobacco use, income, employment status, hand dominance, injury to dominant extremity, mechanism of injury, fracture classification, method of fracture fixation, and presence of concomitant injury. Postoperative complications and reoperation rates were similar between the open and closed groups. Union rates and radiographic alignment one year postoperatively were similar between the open and closed fracture groups. At final follow-up, range of motion parameters, grip strengths, DASH indices, and subjective pain scores were similar between both groups. Discussion Open distal radius fractures treated with early debridement

  16. Early posttraumatic physeal arrest in distal radius after a compression injury.

    PubMed

    Valverde, J A; Albiñana, J; Certucha, J A

    1996-01-01

    Early posttraumatic arrest of the distal radial physis is an uncommon complication and usually appears after type II physeal injury. We report a 13-year-old boy who sustained an injury to his right wrist, incurring an avulsion fracture of ulnar styloid process. Twenty-one months later, a uniform closure of the distal radial physis was observed. An ulnar shortening osteotomy and distal ulnar epiphysiodesis were performed. We discuss different factors of this complication, but crush injury of germinal cells of the growthplate is considered the main etiology.

  17. The Effect of Osteoporosis on Healing of Distal Radius Fragility Fractures.

    PubMed

    Tulipan, Jacob; Jones, Christopher M; Ilyas, Asif M

    2015-10-01

    Although the decision for operative versus nonoperative treatment of distal radius fractures remains subjective and is performed on a case-by-case basis, evaluation and treatment of patients with concomitant osteoporosis requires understanding of the behavior of this injury as a distinct subset of distal radius fractures. Age, infirmity, and osteoporosis affect every aspect of the fracture. Understanding what makes these fractures unique assists surgeons in more effective and efficient treatment. The authors present the current understanding of osteoporotic fragility fractures of the distal radius, focusing on epidemiology, biomechanics of bone healing, and its implication on strategies for management.

  18. Gonad morphogenesis and distal tip cell migration in the Caenorhabditis elegans hermaphrodite

    PubMed Central

    Wong, Ming-Ching; Schwarzbauer, Jean E.

    2013-01-01

    Cell migration and morphogenesis are key events in tissue development and organogenesis. In Caenorhabditis elegans, the migratory path of the distal tip cells determines the morphology of the hermaphroditic gonad. The distal tip cells undergo a series of migratory phases interspersed with turns to form the gonad. A wide variety of genes have been identified as crucial to this process, from genes that encode components and modifiers of the extracellular matrix to signaling proteins and transcriptional regulators. The connections between extracellular and transmembrane protein functions and intracellular pathways are essential for distal tip cell migration, and the integration of this information governs gonad morphogenesis and determines gonad size and shape. PMID:23559979

  19. [Results of Kapandji-Sauvé operation after distal radius fractures].

    PubMed

    Borisch, N; Haussmann, P

    1998-11-01

    Incongruity of the distal radioulnar joint represents a major problem following malunited fractures of the distal radius. A useful solution is the arthrodesis of the distal radioulnar joint with distal ulnar pseudarthrosis as described by Kapandji-Sauvé. The results of this procedure are presented and the indication compared to alternative treatment options discussed. Between 1991 and 1997, 19 patients were treated with a Kapandji-Sauvé procedure, for rheumatoid arthritis in seven and for a malunited fracture of the distal radius in twelve patients. All of the patients with a malunion of the distal radius were followed up 5 to 70 months postoperatively by clinical and X-ray examination. For evaluation the protocol by Martini for malunited fractures of the distal radius was used. All but one patient agreed that the operation had been beneficial and would choose to undergo the same procedure again necessary. Mean forearm rotation improved from 99 to 166 degrees. Preoperative pain was reduced in eleven patients. Two patients were completely pain-free and seven noticed pain during heavy load only. Grip strength improved postoperatively in three patients, remained unchanged in four and was diminished in three. In two patients preoperative measurements were not available. Evaluation by the Martini protocol gave three very good, four good, four fair, and one poor result. In one patient, regeneration of the ulna across the resected segment occurred necessitating a secondary excision. This resulted in a return of forearm rotation of 140 degree and good patient satisfaction. Arthrodesis of the distal radioulnar joint with distal ulnar pseudarthrosis reliably reduces pain and improves forearm rotation after malunited fractures of the distal radius. However, it cannot influence pain originating from the radiocarpal joint. Therefore, patients with advanced radiocarpal arthrosis are not suitable for the operation. We consider the procedure to be indicated when the distal

  20. Use of High-Speed X ray and Video to Analyze Distal Radius Fracture Pathomechanics.

    PubMed

    Gutowski, Christina; Darvish, Kurosh; Liss, Frederic E; Ilyas, Asif M; Jones, Christopher M

    2015-10-01

    The purpose of this study is to investigate the failure sequence of the distal radius during a simulated fall onto an outstretched hand using cadaver forearms and high-speed X ray and video systems. This apparatus records the beginning and propagation of bony failure, ultimately resulting in distal radius or forearm fracture. The effects of 3 different wrist guard designs are investigated using this system. Serving as a proof-of-concept analysis, this study supports this imaging technique to be used in larger studies of orthopedic trauma and protective devices and specifically for distal radius fractures.

  1. Minimizing the complications of intramedullary nailing for distal third tibial shaft and metaphyseal fractures

    PubMed Central

    Yaligod, Vishwanath; Rudrappa, Girish H.; Nagendra, Srinivas; Shivanna, Umesh M.

    2013-01-01

    Background The complications of intramedullary nailing of distal third tibial shaft and metaphyseal fractures have a direct impact on ankle and hind foot function. Methods We retrospectively evaluated 28 patients. Unreamed nail was negotiated across the well reduced fracture till subchondral bone and fixed with 2 to 3 distal locking screws in different planes. Results Fracture union rate was 85%. Three out of 28 patients had malalignment. Mean ankle, hindfoot functional score was 85. Conclusion Complications can be minimized by impacting the unreamed nail till the subchondral bone while maintaining the fracture well reduced and by using multiple distal locking screws in different planes. PMID:24719527

  2. Beyond Race and Place: Distal Sociological Determinants of HIV Disparities

    PubMed Central

    Buot, Max-Louis G.; Bittner, Matthew J.; Burlew, Jacob T.; Nuritdinov, Aziz R.; Robbins, Jennifer R.

    2014-01-01

    Informed behavior change as an HIV prevention tool has yielded unequal successes across populations. Despite decades of HIV education, some individuals remain at high risk. The mainstream media often portrays these risk factors as products of race and national borders; however, a rich body of recent literature proposes a host of complex social factors that influence behavior, including, but not limited to: poverty, income inequality, stigmatizing social institutions and health care access. We examined the relationship between numerous social indicators and HIV incidence across eighty large U.S. cities in 1990 and 2000. During this time, major correlating factors included income inequality, poverty, educational attainment, residential segregation and marriage rates. However, these ecological factors were weighted differentially across risk groups (e.g. heterosexual, intravenous drug use, men who have sex with men (MSM)). Heterosexual risk rose significantly with poor economic indicators, while MSM risk depended more heavily on anti-homosexual stigma (as measured by same-sex marriage laws). HIV incidence among black individuals correlated significantly with numerous economic factors but also with segregation and imbalances in the male:female ratio (often an effect of mass incarceration). Our results support an overall model of HIV ecology where poverty, income inequality and social inequality (in the form of institutionalized racism and anti-homosexual stigma) have over time developed into synergistic drivers of disease transmission in the U.S., inhibiting information-based prevention efforts. The relative weights of these distal factors vary over time and by HIV risk group. Our testable model may be more generally applicable within the U.S. and beyond. PMID:24743728

  3. Isoflurane Selectively Inhibits Distal Mitochondrial Complex I in Caenorhabditis Elegans

    PubMed Central

    Kayser, Ernst-Bernhard; Suthammarak, Wichit; Morgan, Phil G.; Sedensky, Margaret M.

    2011-01-01

    BACKGROUND Complex I of the electron transport chain (ETC) is a possible target of volatile anesthetics (VAs). Complex I enzymatic activities are inhibited by VAs, and dysfunction of complex I can lead to hypersensitivity to VAs in worms and in people. Mutant analysis in Caenorhabditis (C.) elegans suggests that VAs may specifically interfere with complex I function at the binding site for its substrate ubiquinone. We hypothesized that isoflurane inhibits electron transport by competing with ubiquinone for binding to complex I. METHODS Wildtype and mutant C. elegans were used to study the effects of isoflurane on isolated mitochondria. Enzymatic activities of the ETC were assayed and dose-response curves determined using established techniques. Two-dimensional native gels of mitochondrial proteins were performed after exposure of mitochondria to isoflurane. RESULTS Complex I is the most sensitive component of the ETC to isoflurane inhibition; however the proximal portion of complex I (the flavoprotein) is relatively insensitive to isoflurane. Isoflurane and quinone do not compete for a common binding site on complex I. The absolute rate of complex I enzymatic activity in vitro does not predict immobilization of the animal by isoflurane. Isoflurane had no measurable effect on stability of mitochondrial supercomplexes. Reduction of ubiquinone by complex I displayed positive cooperative kinetics not disrupted by isoflurane. CONCLUSIONS Isoflurane directly inhibits complex I at a site distal to the flavoprotein subcomplex. However, we have excluded our original hypothesis that isoflurane and ubiquinone compete for a common hydrophobic binding site on complex I. In addition, immobilization of the nematode by isoflurane is not due to limiting absolute amounts of complex I electron transport as measured in isolated mitochondria. PMID:21467554

  4. The Hybrid Hyrax Distalizer, a new all-in-one appliance for rapid palatal expansion, early class III treatment and upper molar distalization.

    PubMed

    Wilmes, Benedict; Ludwig, Björn; Katyal, Vandana; Nienkemper, Manuel; Rein, Anna; Drescher, Dieter

    2014-09-01

    Growing class III patients with maxillary deficiency may be treated with a maxillary protraction facemask. Because the force generated by this appliance is applied to the teeth, the inevitable mesial migration of the dentition can result in anterior crowding, incisor proclination and a possible need for subsequent extraction therapy. The Hybrid Hyrax appliance, anchored on mini-implants in the anterior palate, can be used to overcome these side-effects during the facemask therapy. In some class III cases, there is also a need for subsequent distalization after the orthopaedic treatment. In this paper, clinical application of the Hybrid Hyrax Distalizer is described, facilitating both orthopaedic advancement of the maxilla and simultaneous orthodontic distalization of the maxillary molars.

  5. [Growth prognosis after para-epiphyseal tangential epiphysial injuries of the lower extremity exemplified by the distal femur: outcome after injuries of epiphyses of the distal femur].

    PubMed

    Weinberg, A M; Castellani, C; Werner, C; Mayr, J

    2002-01-01

    Fractures of the distal end of the femur are rare. Premature partial closure of the physis may occur after metaphyseal fractures. After epiphyseal fractures it has a high incidence of occurrence. The cause of physeal arrest is not known. Stimulation of the physes ends in leg length discrepancy and was seen in 50% of all cases. Spontaneous correction of an axis deviation is possible after antecurvation up to an age of 5 years. But this should be only accepted during therapy of metaphyseal fractures of the distal femur. Side-to-Side deviations remodel in all cases. Aim of therapy in distal epiphyseal fractures should be an anatomical reduction and a definitive retention. Screw osteosynthesis seems to have an advantage.

  6. Distinct subclassification of DRG neurons innervating the distal colon and glans penis/distal urethra based on the electrophysiological current signature.

    PubMed

    Rau, Kristofer K; Petruska, Jeffrey C; Cooper, Brian Y; Johnson, Richard D

    2014-09-15

    Spinal sensory neurons innervating visceral and mucocutaneous tissues have unique microanatomic distribution, peripheral modality, and physiological, pharmacological, and biophysical characteristics compared with those neurons that innervate muscle and cutaneous tissues. In previous patch-clamp electrophysiological studies, we have demonstrated that small- and medium-diameter dorsal root ganglion (DRG) neurons can be subclassified on the basis of their patterns of voltage-activated currents (VAC). These VAC-based subclasses were highly consistent in their action potential characteristics, responses to algesic compounds, immunocytochemical expression patterns, and responses to thermal stimuli. For this study, we examined the VAC of neurons retrogradely traced from the distal colon and the glans penis/distal urethra in the adult male rat. The afferent population from the distal colon contained at least two previously characterized cell types observed in somatic tissues (types 5 and 8), as well as four novel cell types (types 15, 16, 17, and 18). In the glans penis/distal urethra, two previously described cell types (types 6 and 8) and three novel cell types (types 7, 14, and 15) were identified. Other characteristics, including action potential profiles, responses to algesic compounds (acetylcholine, capsaicin, ATP, and pH 5.0 solution), and neurochemistry (expression of substance P, CGRP, neurofilament, TRPV1, TRPV2, and isolectin B4 binding) were consistent for each VAC-defined subgroup. With identification of distinct DRG cell types that innervate the distal colon and glans penis/distal urethra, future in vitro studies related to the gastrointestinal and urogenital sensory function in normal as well as abnormal/pathological conditions may be benefitted.

  7. Distinct subclassification of DRG neurons innervating the distal colon and glans penis/distal urethra based on the electrophysiological current signature

    PubMed Central

    Petruska, Jeffrey C.; Cooper, Brian Y.; Johnson, Richard D.

    2014-01-01

    Spinal sensory neurons innervating visceral and mucocutaneous tissues have unique microanatomic distribution, peripheral modality, and physiological, pharmacological, and biophysical characteristics compared with those neurons that innervate muscle and cutaneous tissues. In previous patch-clamp electrophysiological studies, we have demonstrated that small- and medium-diameter dorsal root ganglion (DRG) neurons can be subclassified on the basis of their patterns of voltage-activated currents (VAC). These VAC-based subclasses were highly consistent in their action potential characteristics, responses to algesic compounds, immunocytochemical expression patterns, and responses to thermal stimuli. For this study, we examined the VAC of neurons retrogradely traced from the distal colon and the glans penis/distal urethra in the adult male rat. The afferent population from the distal colon contained at least two previously characterized cell types observed in somatic tissues (types 5 and 8), as well as four novel cell types (types 15, 16, 17, and 18). In the glans penis/distal urethra, two previously described cell types (types 6 and 8) and three novel cell types (types 7, 14, and 15) were identified. Other characteristics, including action potential profiles, responses to algesic compounds (acetylcholine, capsaicin, ATP, and pH 5.0 solution), and neurochemistry (expression of substance P, CGRP, neurofilament, TRPV1, TRPV2, and isolectin B4 binding) were consistent for each VAC-defined subgroup. With identification of distinct DRG cell types that innervate the distal colon and glans penis/distal urethra, future in vitro studies related to the gastrointestinal and urogenital sensory function in normal as well as abnormal/pathological conditions may be benefitted. PMID:24872531

  8. Subintimal TRAnscatheter Withdrawal (STRAW) of hematomas compressing the distal true lumen: a novel technique to facilitate distal reentry during recanalization of chronic total occlusion (CTO).

    PubMed

    Smith, Elliot J; Di Mario, Carlo; Spratt, James C; Hanratty, Colm G; de Silva, Ranil; Lindsay, Alistair C; Grantham, J Aaron

    2015-01-01

    The development of a large hematoma impairing visualization of the distal true lumen is a recognized complication of antegrade recanalization of chronic total occlusions, often forcing the operator to abort the procedure or switch to a retrograde approach. We describe a novel technique utilizing an over-the-wire balloon inflated in the proximal occluded vessel to block inflow and allow aspiration of the blood from the subintimal space. This decompressed the true lumen, restored distal visualization, and allowed successful reentry using a dedicated technology. Utilization of this novel technique may rescue antegrade recanalization attempts complicated by large subintimal hematomas.

  9. A Noble, Easy and Conceptual Radiographic Analysis to Assess the Type of Tooth Movement (Molar Distalization)

    PubMed Central

    Prakash, Anaveri Thimmappa; Deepthi; Naik, Atri

    2015-01-01

    Context and Aim Bodily tooth movement is desirable in the field of Orthodontics and so is with molar distalization. Till date there is no such analysis available which could gauge and quantify the molar distalization and the type of tooth movement achieved, therefore one was required. Materials and Methods An OPG and Lateral cephalogram was used taking Inter orbitale plane and FH plane respectively as reference lines and the analysis was devised to measure the amount and type of tooth movement achieved in distalization of molar. Conclusion This analysis is a noble, easy and conceptual analysis to assess the type of tooth movement achieved during molar distalization and other molar movements using Lateral cephalogram and orthopantomogram. PMID:26436040

  10. Physeal growth arrest of the distal radius treated by the Ilizarov technique. Report of a case.

    PubMed

    Aston, J W; Henley, M B

    1989-07-01

    Growth arrest of the distal radius may follow a severe injury to the growth plate. When the growth of the distal radius ceases in the child, continuing ulnar growth results in radial deviation of the hand and dislocation of the distal radioulnar joint. Treatment options in such a limb-length discrepancy are resection of the physeal bony bridge, lengthening of the shaft of the radius with bone graft using the principle of the Wagner technique, resection or epiphysiodesis of the distal ulna, and lengthening through a metaphyseal corticotomy without the use of bone graft. We report a case of metaphyseal lengthening of the radius employing the Ilizarov external fixator for controlled distraction osteogenesis.

  11. A Rare Giant Cell Tumor of the Distal Fibula and its Management.

    PubMed

    Vaishya, Raju; Kapoor, Chirag; Golwala, Paresh; Agarwal, Amit Kumar; Vijay, Vipul

    2016-07-01

    Giant Cell Tumour (GCT) of the distal fibula is extremely rare and poses challenges in the surgical management. Wide excision or intralesional curettage, along with adjuvant chemical cauterisation can prevent the recurrence of GCT. The excised bone gap needs reconstruction using tricortical iliac autograft and supportive plate fixation. In addition to wide excision, preservation of ankle mortise is advisable in locally aggressive and large lesions of the distal fibula. We report a GCT of the distal fibula in a young female patient. As part of the treatment, en bloc resection, chemical cauterisation with phenol, and distal fibula reconstruction with a tricortical iliac crest bone graft was done. Eighteen months after the treatment, the patient has no recurrence and her ankle is stable with full range of movement. We suggest this method to be worthwhile for the treatment of this uncommon lesion in quantifying recurrence and functional outcome.

  12. [Early corrective osteotomy after secondary displaced distal radius fractures in children].

    PubMed

    Boeckers, P; Gehrmann, S V; Wild, M; Schädel-Höpfner, M; Windolf, J

    2014-02-01

    Secondary fracture displacement before osseous consolidation of distal radius fractures in children occasionally leads to restricted forearm rotation. So far, there is no consistent treatment recommendation to correct this complication. We report on 5 children with an age of 8-13 years (mean age 12.3 years, 4 boys, 1 girl) with secondary displaced distal radius fractures and high functional deficits in forearm rotation (mean ROM for pro-/supination 70-0-30°) after osseous consolidation. We performed corrective osteotomies of the distal radius using a palmar approach after a mean of 38 days. Stabilisation was achieved with a fixed-angle plate system. At the final follow-up examination (mean 9 months) the forearm rotation was normal. No complications were observed. We consider corrective osteotomies of the distal radius in children with deficits of forearm rotation to be a possible strategy. Early corrective osteotomies can lead to a predictable increase of function through reestablishing normal articulation.

  13. Distal Common Bile Duct Tuberculosis with Obstructive Jaundice: A Case Report.

    PubMed

    Chowdhury, M M; Ullah, A K; Hossain, M J; Mohammed, S; Towhid, S M; Sobhan, S A; Khan, Z H; Jannat, F; Kabir, M H

    2017-01-01

    Tuberculosis (TB) isolated in Common Bile Duct (CBD) is very rare and its treatment is somewhat controversial. We report a case of distal CBD tuberculosis diagnosed as cholangiocarcinoma. A 40 year old man presented with obstructive jaundice without abdominal pain, fever or weight loss. Ultrasonography and Magnetic Resonance Cholangio-Pancreatography (MRCP) indicated a mass lesion in the Distal CBD, which caused structure of the distal common bile duct. As Cholangiocarcinoma was suspected, he underwent Whipple procedure (pancreaticoduodenectomy). Histological examination of resected specimen revealed typical features of tuberculosis in the distal CBD, pancreatic head and lymph nodes. The rest of the abdominal cavity was unremarkable. Anti-microbial therapy for tuberculosis is started for 12 month course and he is well.

  14. Bilateral Asymmetry in Upper Extremities Is More Pronounced in Distal Compared to Proximal Joints.

    PubMed

    Aune, T K; Ettema, G; Vereijken, B

    2016-01-01

    The authors' aim was to compare spatial and temporal accuracy in proximal versus distal joints in upper extremities. Given the morphological differences in corticospinal and corticomotoneuronal projections for proximal and distal muscles, they hypothesized that bilateral asymmetry would be larger for distal than for proximal joints. Twelve participants performed isolated flexion-extension movements with the shoulders and index fingers. Angular range of motion of finger and shoulder movements was kept constant. The results showed significant bilateral asymmetry for both proximal and distal joints for both spatial and temporal accuracy. More importantly, bilateral asymmetry was significantly larger for the index fingers than for the shoulders for both spatial and temporal variables, as hypothesized. These results at the behavioral level pave the way for further studies that combine direct measures of neural activation with behavioral measures to further illuminate the potential link between bilateral communication and laterality effects in motor performance.

  15. Ulnar buttress arthroplasty after enbloc resection of a giant cell tumor of the distal ulna

    PubMed Central

    Naik, Monappa A; Sujir, Premjit; Rao, Sharath K; Tripathy, Sujit K

    2013-01-01

    Enbloc resection with or without ulnar stump stabilization is the recommended treatment for giant cell tumors (GCT) of the distal ulna. A few sporadic reports are available where authors have described various procedures to prevent ulnar stump instability and ulnar translation of carpal bones. We report a GCT of the distal ulna in a 43-year-old male which was resected enbloc. The distal radioulnar joint was reconstructed by fixing an iliac crest graft to the distal end of the radius (ulnar buttress arthroplasty) and the ulnar stump was stabilized with extensor carpi ulnaris tenodesis. After a followup at three years, there was no evidence of tumor recurrence or graft resorption; the patient had a normal range of movement of the wrist joint and the functional outcome was excellent as per the score of Ferracini et al. PMID:23682187

  16. Volar Locking Plate Breakage after Nonunion of a Distal Radius Osteotomy

    PubMed Central

    Rodríguez-Alabau, Sergi; Soldado, Francisco; Mir, Xavier

    2016-01-01

    We report a 38-year-old male with a nonunion followed by plate breakage after volar plating of a distal radius osteotomy. Volar locking plates have added a new approach to the treatment of distal radius malunions, due to a lower morbidity of the surgical approach and the strength of the final construction, allowing early mobilization and return to function. Conclusion. Plate breakage is an uncommon complication of volar locking plate fixation. To our knowledge, few cases have been described after a distal radius fracture and no case has been described after a distal radius corrective osteotomy. In the present case, plate breakage appears to have occurred as a result of a combination of multiple factors as the large corrective lengthening osteotomy, the use of demineralized bone matrix instead of bone graft, and the inappropriate fixation technique as an unfilled screw on the osteotomy site, rather than the choice of plate. PMID:28003828

  17. An in vivo study of the effect of distal femoral resection on passive knee extension.

    PubMed

    Smith, Conrad K; Chen, Justin A; Howell, Stephen M; Hull, Maury L

    2010-10-01

    A previous study showed that 1 mm of distal femoral resection restored knee extension 4.5°. We determined the relationship with a more accurate measurement technique. Twenty-six subjects treated with total knee arthroplasty were studied. Digital photographs of the extended knee with and without 1.5 and 3.0 mm thick augments placed between the femoral component and distal femur were analyzed, and knee extension was measured. One millimeter of distal femoral resection restored 1.8° of extension that is less correction than the previous study reported. Because an attempt to correct a 10° extension deficit by resecting the distal femur could require 5 mm or more of bone removal that moves the joint line too proximal, we recommend exploring other techniques before resecting the femur.

  18. Secondary displacement of distal radius fractures treated by bridging external fixation.

    PubMed

    Farah, N; Nassar, L; Farah, Z; Schuind, F

    2014-05-01

    Loss of reduction remains an important problem after treatment of distal radius fractures, whatever the type of bone fixation. We assessed retrospectively the rate of secondary displacement after external fixation of distal radius fractures in order to identify possible risk factors for instability. We reviewed the pre-operative and serial post-operative radiographs of a retrospective series of 35 distal radius fractures treated by bridging external fixation. When classified according to the Société Française d'Orthopédie et Traumatologie (SOFCOT) criteria, the rate of secondary displacement was 48.5%. At final follow up, the reduction was anatomical in 12% and acceptable in 83%. There was malunion in 5%. The loss of reduction concerned primarily the distal radius palmar tilt and was moderate. No correlation was found with age, gender, type of fracture, degree of initial displacement, associated ulnar fracture, or seniority of the treating surgeon.

  19. The primary Sauve-Kapandji procedure--for treatment of comminuted distal radius and ulnar fractures.

    PubMed

    Horii, E; Ohmachi, T; Nakamura, R

    2005-02-01

    We have performed primary Sauve-Kapandji procedures on four patients with severe open comminuted fractures of both the distal radius and ulna. The fragmented distal ulna was fixed to the sigmoid notch in order to stabilize the ulnar side of the carpus, and a proximal pseudoarthrosis was maintained for forearm rotation. All the distal radial fractures united without major complications. The mean wrist flexion/extension arc was 76 degrees , the mean pronation/supination arc was 135 degrees, and grip strength was 64% of the contralateral side. All patients returned to their work or daily activities within short time period without any additional surgical treatment, except for removal of implants in three patients. The primary Sauve-Kapandji procedure is effective for the reconstruction of severely combined distal radius and ulnar fractures.

  20. Left-sided thoracoscopy in the prone position for surgery of distal esophageal benign pathologies

    PubMed Central

    Issaka, Adamu; Kara, Hasan Volkan; Eldem, Barkin

    2014-01-01

    Exposure of the distal esophagus can be achieved by a wide variety of surgical approaches. The standard procedure is mostly by laparoscopy. In cases where laparoscopy is relatively contraindicated, thoracoscopy is preferred. In this case, exposure of the distal esophagus from the aorta, heart and lung is technically challenging using thoracoscopy in the right lateral decubitus position. Surgery in the prone position for esophageal cancer has been successfully described in previous literature. We present our experience with left-sided thoracoscopy in the prone position in three patients with benign distal esophageal pathologies. This approach provided a much better exposure of the distal esophagus and enabled a successful surgery to be done in all patients with less manipulation of the lung. PMID:27489640

  1. The management of nonunion and malunion of the distal humerus--a 30-year experience.

    PubMed

    Jupiter, Jesse B

    2008-01-01

    This personal series of nonunions of the distal humerus reviews unique features of this problem, categorizes them according to unique anatomic features, and presents pitfalls and pearls in the management of these complex reconstructive problems.

  2. Coverage of defects over toes with distally based local flaps: A report of four cases.

    PubMed

    Koul, Ashok Raj; Patil, Rahul K; Philip, Vinoth Kumar

    2008-01-01

    Reconstruction of the distal foot, especially of the toe has always been a challenging problem. Various methods have been tried with variable success rates and limitations. Presented here is a series of four cases, where distally based flaps were used. Two of them were Extensor Digitorum Brevis (EDB) muscle flaps and the other two were first dorsal metatarsal artery (FDMA) based skin flaps. One in each of the two was augmented with a plantar V-Y advancement flap. All flaps survived completely without any flap- or donor site-related complications. The patients were ambulated two weeks following the reconstruction and were symptom-free after an average follow-up of thirteen months. Distal flaps based on the dorsalis pedis system provide a reliable cover for distal foot defects.

  3. Intramedullary plate fixation of a distal humerus fracture: a case report.

    PubMed

    Russell, George V; Pearsall, Albert W

    2002-05-01

    A case of a complex distal humeral fracture is presented. The patient lacked sufficient bony architecture to allow for conventional reconstruction. A technique is described using an intramedullary plate to obtain bony stabilization and permit early range of motion exercises.

  4. Forced Arterial Suction Thrombectomy Using Distal Access Catheter in Acute Ischemic Stroke

    PubMed Central

    Lee, Ho-Cheol; Kang, Dong-Hun; Hwang, Yang-Ha; Kim, Yong-Sun

    2017-01-01

    Historical innovations in mechanical thrombectomy devices and strategies for ischemic stroke have resulted in improved angiographic outcomes and better clinical outcomes. Various devices have been used, but the two most common approaches are aspiration thrombectomy and stent-retrieval thrombectomy. Aspiration thrombectomy has advanced from the traditional Penumbra system to forced arterial suction thrombectomy and a direct aspiration first-pass technique. Newer generation aspiration catheters with flexible distal tips and a larger bore have demonstrated faster and better recanalization relative to older devices. Recently, several species of distal access catheters have similar structural characteristics to the Penumbra reperfusion catheter. Therefore, we used the distal access catheter for forced arterial suction thrombectomy in three patients with acute ischemic stroke. In each case, we achieved fast and complete recanalization without significant complications. Forced arterial suction thrombectomy using a distal access catheter might provide another option for mechanical thrombectomy in patients with acute ischemic stroke. PMID:28316869

  5. Insufficiency fractures of the distal tibia misdiagnosed as cellulitis in three patients with rheumatoid arthritis

    SciTech Connect

    Straaton, K.V.; Lopez-Mendez, A.; Alarcon, G.S. )

    1991-07-01

    We describe 3 patients with rheumatoid arthritis who presented with diffuse pain, swelling, and erythema of the distal aspect of the lower extremity, suggestive of either cellulitis or thrombophlebitis, but were found to have insufficiency fractures of the distal tibia. The value of technetium-99m diphosphonate bone scintigraphy in the early recognition of these fractures and a possible explanation for the associated inflammatory symptoms are discussed.

  6. Hypokalemic quadriparesis and rhabdomyolysis as a rare presentation of distal renal tubular acidosis

    PubMed Central

    Ahmad Bhat, Manzoor; Ahmad Laway, Bashir; Mustafa, Farhat; Shafi Kuchay, Mohammad; Mubarik, Idrees; Ahmad Palla, Nazir

    2014-01-01

    Distal renal tubular acidosis is a syndrome of abnormal urine acidification and is characterized by hyperchloremic metabolic acidosis, hypokalemia, hypercalciurea, nephrocalcinosis and nephrolithiasis. Despite the presence of persistent hypokalemia, acute muscular paralysis is rarely encountered in males. Here, we will report an eighteen year old male patient who presented with flaccid quadriparesis and was subsequently found to have rhabdomyolysis, severe short stature, skeletal deformities and primary distal renal tubular acidosis. PMID:25250276

  7. Ineffective Esophageal Motility Progressing into Distal Esophageal Spasm and Then Type III Achalasia

    PubMed Central

    Carlson, Dustin A.; Kahrilas, Peter J.; Pandolfino, John E.

    2016-01-01

    The clinical significance of minor esophageal motility disorders is unclear, though they typically carry a benign course. Distal esophageal spasm progressing to achalasia has been reported, although it appears to be rare. We report a case of a patient with dysphagia and chest pain who was found to have ineffective esophageal motility on high-resolution manometry, which developed into distal esophageal spasm and then progressed to type III achalasia. PMID:28119934

  8. Is distal motor and/or sensory demyelination a distinctive feature of anti-MAG neuropathy?

    PubMed

    Lozeron, Pierre; Ribrag, Vincent; Adams, David; Brisset, Marion; Vignon, Marguerite; Baron, Marine; Malphettes, Marion; Theaudin, Marie; Arnulf, Bertrand; Kubis, Nathalie

    2016-09-01

    To report the frequency of the different patterns of sensory and motor electrophysiological demyelination distribution in patients with anti-MAG neuropathy in comparison with patients with IgM neuropathy without MAG reactivity (IgM-NP). Thirty-five anti-MAG patients at early disease stage (20.1 months) were compared to 23 patients with IgM-NP; 21 CIDP patients and 13 patients with CMT1a neuropathy were used as gold standard neuropathies with multifocal and homogeneous demyelination, respectively. In all groups, standard motor and sensory electrophysiological parameters, terminal latency index and modified F ratio were investigated. Motor electrophysiological demyelination was divided in four profiles: distal, homogeneous, proximal, and proximo-distal. Distal sensory and sensorimotor demyelination were evaluated. Anti-MAG neuropathy is a demyelinating neuropathy in 91 % of cases. In the upper limbs, reduced TLI is more frequent in anti-MAG neuropathy, compared to IgM-NP. But, predominant distal demyelination of the median nerve is encountered in only 43 % of anti-MAG neuropathy and is also common in IgM-NP (35 %). Homogeneous demyelination was the second most frequent pattern (31 %). Concordance of electrophysiological profiles across motor nerves trunks is low and median nerve is the main site of distal motor conduction slowing. Reduced sensory conduction velocities occurs in 14 % of patients without evidence of predominant distal slowing. Simultaneous sensory and motor distal slowing was more common in the median nerve of anti-MAG neuropathy than IgM-NP. Electrophysiological distal motor demyelination and sensory demyelination are not a distinctive feature of anti-MAG reactivity. In anti-MAG neuropathy it is mainly found in the median nerve suggesting a frequent nerve compression at wrist.

  9. [Joint surface resection with a minimally invasive dorsal approach for arthrodesis of the distal interphalangeal joint].

    PubMed

    Ayala-Gamboa, U; Domínguez-Chacón, N D

    2015-01-01

    Degenerative joint disease of the distal interphalangeal joint of the fingers precedes its occurrence in all the remaining regions of the body and produces major disability. We describe a distal interphalangeal arthrodesis technique performed with minimally invasive surgery. Case etiology was varied and mean follow-up was 10 months. All cases healed and functional recovery started at postoperative week two. This is a reproducible technique that produces satisfactory results in the short and medium term.

  10. Paraneoplastic Necrotizing Autoimmune Myopathy in a Patient Undergoing Laparoscopic Pancreatoduodenectomy for Distal Cholangiocarcinoma

    PubMed Central

    van Dijk, Stefan; van der Kooi, Anneke J.; Aronica, Eleonora; van Gulik, Thomas M.; Busch, Olivier R.; Besselink, Marc G.

    2016-01-01

    A 73-year-old male presented with jaundice and severe muscle weakness. He was diagnosed with distal cholangiocarcinoma and paraneoplastic necrotizing autoimmune myopathy (NAM). Treatment of NAM consisted of dexamethasone pulse therapy, prednisone, and single-dose intravenous immunoglobulin. The distal cholangiocarcinoma was resected through a total laparoscopic pancreatoduodenectomy. After hospital discharge, muscle strength initially increased postoperatively; however, pneumonia resulted in the deterioration of his general condition and death 5 months after the diagnosis of paraneoplastic NAM. PMID:27843429

  11. Anatomy, pathology, and physiology of the tracheobronchial tree: emphasis on the distal airways.

    PubMed

    Hyde, Dallas M; Hamid, Qutayba; Irvin, Charles G

    2009-12-01

    This article covers the airway tree with respect to anatomy, pathology, and physiology. The anatomic portion discusses various primate groups so as to help investigators understand similarities and differences between animal models. An emphasis is on distal airway findings. The pathology section focuses on the inflammatory responses that occur in proximal and distal airways. The physiologic review brings together the anatomic and pathologic components to the functional state and proposes ways to evaluate the small airways in patients with asthma.

  12. Minimally Invasive Surgical Approach to Distal Fibula Fractures: A Technique Tip

    PubMed Central

    Gonzalez, Tyler; Chien, Bonnie; Ghorbanhoseini, Mohammad; Kwon, John Y.

    2017-01-01

    Wound complications following ankle fracture surgery are a major concern. Through the use of minimally invasive surgical techniques some of these complications can be mitigated. Recent investigations have reported on percutaneous fixation of distal fibula fractures demonstrating similar radiographic and functional outcomes to traditional open approaches. The purpose of this manuscript is to describe in detail the minimally invasive surgical approach for distal fibula fractures. PMID:28271086

  13. Distal radius fracture after Sauvé-Kapandji procedure in a rheumatoid arthritis patient.

    PubMed

    Ochi, Kensuke; Horiuchi, Yukio; Matsumura, Takashi; Nakamura, Mitsukazu; Takei, Terue; Yabe, Hiroki

    2012-04-01

    We report a case of distal radius fracture after a Sauvé-Kapandji procedure combined with synovectomy and tendon transfer in a rheumatoid arthritis patient. This case shared several unusual features that were also seen in a previously reported case. Based on these features, we discuss favorable surgical treatment for the rheumatoid wrist with extensor tendon rupture, and also the optimal treatment for distal radius fracture after such procedures.

  14. Mononeuropathy of a distal branch of the femoral nerve in a body building champion

    PubMed Central

    Padua, L; D'Aloya, E; LoMonaco, M; Padua, R; Gregori, B; Tonali, P

    1997-01-01

    A unique case of a body building champion with localised atrophy of the distal portion of the vastus lateralis muscle is reported; neurophysiological evaluation suggests a selective lesion of a distal branch of the vastus lateralis nerve (a motor branch of the femoral nerve). A necroscopic study in four cases was performed to better clarify the site and mechanism of nerve lesion. The data suggest that stretching and compression of the nerve has probably occurred during strenous exercise.

 PMID:9408112

  15. Ineffective Esophageal Motility Progressing into Distal Esophageal Spasm and Then Type III Achalasia.

    PubMed

    Samo, Salih; Carlson, Dustin A; Kahrilas, Peter J; Pandolfino, John E

    2016-08-01

    The clinical significance of minor esophageal motility disorders is unclear, though they typically carry a benign course. Distal esophageal spasm progressing to achalasia has been reported, although it appears to be rare. We report a case of a patient with dysphagia and chest pain who was found to have ineffective esophageal motility on high-resolution manometry, which developed into distal esophageal spasm and then progressed to type III achalasia.

  16. Toward endoscopes with no distal optics: video-rate scanning microscopy through a fiber bundle.

    PubMed

    Andresen, Esben Ravn; Bouwmans, Géraud; Monneret, Serge; Rigneault, Hervé

    2013-03-01

    We report a step toward scanning endomicroscopy without distal optics. The focusing of the beam at the distal end of a fiber bundle is achieved by imposing a parabolic phase profile across the exit face with the aid of a spatial light modulator. We achieve video-rate images by galvanometric scanning of the phase tilt at the proximal end. The approach is made possible by the bundle, designed to have very low coupling between cores.

  17. Associations of red meat, fat, and protein intake with distal colorectal cancer risk.

    PubMed

    Williams, Christina Dawn; Satia, Jessie A; Adair, Linda S; Stevens, June; Galanko, Joseph; Keku, Temitope O; Sandler, Robert S

    2010-01-01

    Studies have suggested that red and processed meat consumption elevate the risk of colon cancer; however, the relationship between red meat, as well as fat and protein, and distal colorectal cancer (CRC) specifically is not clear. We determined the risk of distal CRC associated with red and processed meat, fat, and protein intakes in Whites and African Americans. There were 945 cases (720 White, 225 African American) of distal CRC and 959 controls (800 White, 159 African American). We assessed dietary intake in the previous 12 mo. Multivariate logistic regression analyses were used to obtain odds ratios (OR) and 95% confidence intervals (95% CI). There was no association between total, saturated, or monounsaturated fat and distal CRC risk. In African Americans, the OR of distal CRC for the highest category of polyunsaturated fat intake was 0.28 (95% CI = 0.08-0.96). The percent of energy from protein was associated with a 47% risk reduction in Whites (Q4 OR = 0.53, 95% CI = 0.37-0.77). Red meat consumption in Whites was associated with a marginally significant risk reduction (Q4 OR = 0.66, 95% CI = 0.43-1.00). Our results do not support the hypotheses that fat, protein, and red meat increase the risk of distal CRC.

  18. Shape Ontogeny of the Distal Femur in the Hominidae with Implications for the Evolution of Bipedality.

    PubMed

    Tallman, Melissa

    2016-01-01

    Heterochrony has been invoked to explain differences in the morphology of modern humans as compared to other great apes. The distal femur is one area where heterochrony has been hypothesized to explain morphological differentiation among Plio-Pleistocene hominins. This hypothesis is evaluated here using geometric morphometric data to describe the ontogenetic shape trajectories of extant hominine distal femora and place Plio-Pleistocene hominins within that context. Results of multivariate statistical analyses showed that in both Homo and Gorilla, the shape of the distal femur changes significantly over the course of development, whereas that of Pan changes very little. Development of the distal femur of Homo is characterized by an elongation of the condyles, and a greater degree of enlargement of the medial condyle relative to the lateral condyle, whereas Gorilla are characterized by a greater degree of enlargement of the lateral condyle, relative to the medial. Early Homo and Australopithecus africanus fossils fell on the modern human ontogenetic shape trajectory and were most similar to either adult or adolescent modern humans while specimens of Australopithecus afarensis were more similar to Gorilla/Pan. These results indicate that shape differences among the distal femora of Plio-Pleistocene hominins and humans cannot be accounted for by heterochrony alone; heterochrony could explain a transition from the distal femoral shape of early Homo/A. africanus to modern Homo, but not a transition from A. afarensis to Homo. That change could be the result of genetic or epigenetic factors.

  19. Distal femoral cut in total knee arthroplasty in a Brazilian population☆

    PubMed Central

    Costa, Marcos Areias Vieira; Mozella, Alan de Paula; Cobra, Hugo Alexandre de Araujo Barros

    2015-01-01

    Objective To determine the ideal angle for making the distal femoral cut in total knee arthroplasty in a Brazilian population. Methods Panoramic radiographs of the lower limbs bearing weight from 79 patients (57 women and 22 men) were studied, totaling 107 knees with an indication for total knee arthroplasty. The femoral anatomical axis, femoral mechanical axis and cervical-diaphyseal angle were traced out. The angle of the femoral cut was determined from the meeting point between the femoral anatomical and mechanical axes. The ideal degree of femoral valgus was compared between men and women and between knees presenting varus and valgus alignment of the lower limb. The ideal distal femoral cut was also correlated with the cervical-diaphyseal angle. Results The ideal femoral valgus angle ranged from 4.2 to 8.6 degrees, with a mean of 6.3 degrees. There was no statistically significant difference in the distal femoral cut between patients with coronal varus and valgus alignment (p = 0.180). Comparing men and women, there was no statistically significant difference regarding the ideal femoral valgus between the groups (p = 0.057). The cervical-diaphyseal angle presented an inverse relationship with the distal femoral cut. Conclusions The mean angle between the femoral mechanical and anatomical axes was 6.3 degree. Neither preoperative coronal alignment nor sex had any influence on the distal femoral cut. The cervical-diaphyseal angle presented an inverse relationship with the distal femoral cut. PMID:26229933

  20. Volar morphology of the distal radius in axial planes: a quantitative analysis.

    PubMed

    Oura, Keiichiro; Oka, Kunihiro; Kawanishi, Yohei; Sugamoto, Kazuomi; Yoshikawa, Hideki; Murase, Tsuyoshi

    2015-04-01

    To investigate the cause of rupture of the flexor pollicis longus (FPL) after volar plate fixation of distal radius fractures, previous studies have examined the shape of the distal radius in the sagittal plane or in the lateral view. However, there are no reports on the anatomical shape of the volar surface concavity of the distal radius in the axial plane. We hypothesized that this concavity might contribute to the mismatch between the plate and the surface of the radius. To test this hypothesis, we constructed three-dimensional models of the radius and FPL based on computed tomography scans of 70 normal forearms. We analyzed axial cross-sectional views with 2 mm intervals. In all cases, the volar surface of the distal radius was concave in the axial plane. The concavity depth was maximum at 6 mm proximal to the palmar edge of the lunate fossa and progressively decreased toward the proximal radius. FPL was closest to the radius at 2 mm proximal to the palmar edge of the lunate fossa. The volar surface of the distal radius was externally rotated from proximal to distal. These results may help to develop new implants which fit better to the radius and decrease tendon irritation.

  1. Sources of calcium for contraction of distal circular muscle or taenia coli in the rabbit.

    PubMed

    Sevy, N; Snape, W J

    1988-06-01

    Studies were performed on proximal taenia coli and distal circular muscle from the rabbit to determine if the source of Ca2+ required for bethanechol stimulation of contraction was similar after permeabilizing the tissues with saponin. The EC50 for Ca2+ stimulation of contraction was pCa 6.1 +/- 0.1 for both tissues. The peak response occurred at pCa 4.5. The addition of 1 microM calmodulin did not alter the Ca2+ EC50 or the peak response. Caffeine (20 mM) stimulated contraction of both taenia coli and distal circular muscle. The caffeine-stimulated contractile response was threefold greater in the taenia than in the distal circular muscle (P less than 0.05). Perfusion of thin strips of colonic muscle with buffer, containing 10(-7) M Ca2+, reduced the amplitude of bethanechol-stimulated contraction. The perfusion time to reduce the contraction by 50% was greater in the proximal muscle (2.4 +/- 0.1 min) than in the distal muscle (1.1 +/- 0.5 min) (P less than 0.001). These data suggest that 1) the intracellular Ca2+ concentration necessary for contraction is similar in the proximal and distal colon and 2) the intracellular Ca2+ stores appear to be greater in proximal taenia coli compared with distal circular muscle.

  2. One size does not fit all: distal radioulnar joint dysfunction after volar locking plate fixation.

    PubMed

    Jones, Christopher W; Lawson, Richard D

    2014-02-01

    Background Fractures of the distal radius are among the most common injuries treated by orthopedic surgeons worldwide. Failure to restore distal radius alignment can lead to fracture malunion and poor clinical outcomes, including distal radioulnar joint (DRUJ) instability and limitation of motion. Case Description We present a unique case of DRUJ dysfunction following volar plate fixation of bilateral distal radius fractures and analyze the biomechanical causes of this complication. As a result of a relatively excessive tilt of the precontoured locking plate (in comparison to the patient's particular anatomy), the fracture on one side was "over-reduced," disrupting the biomechanics of the DRUJ, causing a supination block. Clinical Relevance Volar locking plates are not a panacea to all distal radius fractures. Plate selection and fixation technique must include consideration of patient anatomy. Robust plates offer the advantage of providing rigid fixation but can be difficult to contour when reconstructing normal anatomy. Restoration of patient-specific anatomy is crucial to the management of distal radius fractures.

  3. A reliable method for evaluating upper molar distalization: Superimposition of three-dimensional digital models

    PubMed Central

    Nalcaci, Ruhi; Bicakci, Ali Altug; Ozturk, Firat; Babacan, Hasan

    2015-01-01

    Objective The aim of this study was to evaluate the reliability of measurements obtained after the superimposition of three-dimensional (3D) digital models by comparing them with those obtained from lateral cephalometric radiographs and photocopies of plaster models for the evaluation of upper molar distalization. Methods Data were collected from plaster models and lateral cephalometric radiographs of 20 Class II patients whose maxillary first molars were distalized with an intraoral distalizer. The posterior movements of the maxillary first molars were evaluated using lateral cephalometric radiographs (group CP), photocopies of plaster models (group PH), and digitized 3D models (group TD). Additionally, distalization and expansion of the other teeth and the degrees of molar rotation were measured in group PH and group TD and compared between the two groups. Results No significant difference was observed regarding the amount of molar distalization among the three groups. A comparison of the aforementioned parameters between group PH and group TD did not reveal any significant difference. Conclusions 3D digital models are reliable to assess the results of upper molar distalization and can be considered a valid alternative to conventional measurement methods. PMID:25798414

  4. Cell polarity and spindle orientation in the distal epithelium of embryonic lung.

    PubMed

    El-Hashash, Ahmed H; Warburton, David

    2011-02-01

    A proper balance between self-renewal and differentiation of lung-specific progenitors at the distal epithelial tips is absolutely required for normal lung morphogenesis. Cell polarity and mitotic spindle orientation play a critical role in the self-renewal/differentiation of epithelial cells and can impact normal physiological processes, including epithelial tissue branching and differentiation. Therefore, understanding the behavior of lung distal epithelial progenitors could identify innovative solutions to restoring normal lung morphogenesis. Yet little is known about cell polarity, spindle orientation, and segregation of cell fate determinant in the embryonic lung epithelium, which contains progenitor cells. Herein, we provide the first evidence that embryonic lung distal epithelium is polarized and highly mitotic with characteristic perpendicular cell divisions. Consistent with these findings, mInsc, LGN, and NuMA polarity proteins, which control spindle orientation, are asymmetrically localized in mitotic distal epithelial progenitors of embryonic lungs. Furthermore, the cell fate determinant Numb is asymmetrically distributed at the apical side of distal epithelial progenitors and segregated to one daughter cell in most mitotic cells. These findings provide evidence for polarity in distal epithelial progenitors of embryonic lungs and provide a framework for future translationally oriented studies in this area.

  5. Shape Ontogeny of the Distal Femur in the Hominidae with Implications for the Evolution of Bipedality

    PubMed Central

    Tallman, Melissa

    2016-01-01

    Heterochrony has been invoked to explain differences in the morphology of modern humans as compared to other great apes. The distal femur is one area where heterochrony has been hypothesized to explain morphological differentiation among Plio-Pleistocene hominins. This hypothesis is evaluated here using geometric morphometric data to describe the ontogenetic shape trajectories of extant hominine distal femora and place Plio-Pleistocene hominins within that context. Results of multivariate statistical analyses showed that in both Homo and Gorilla, the shape of the distal femur changes significantly over the course of development, whereas that of Pan changes very little. Development of the distal femur of Homo is characterized by an elongation of the condyles, and a greater degree of enlargement of the medial condyle relative to the lateral condyle, whereas Gorilla are characterized by a greater degree of enlargement of the lateral condyle, relative to the medial. Early Homo and Australopithecus africanus fossils fell on the modern human ontogenetic shape trajectory and were most similar to either adult or adolescent modern humans while specimens of Australopithecus afarensis were more similar to Gorilla/Pan. These results indicate that shape differences among the distal femora of Plio-Pleistocene hominins and humans cannot be accounted for by heterochrony alone; heterochrony could explain a transition from the distal femoral shape of early Homo/A. africanus to modern Homo, but not a transition from A. afarensis to Homo. That change could be the result of genetic or epigenetic factors. PMID:26886416

  6. Chloroperoxidase-Catalyzed Epoxidation of Cis-β-Methylstyrene:Distal Pocket Flexibility Tunes Catalytic Reactivity

    PubMed Central

    Morozov, Alexander N.; Chatfield, David C.

    2012-01-01

    Chloroperoxidase, the most versatile heme protein, has a hybrid active site pocket that shares structural features with peroxidases and cytochrome P450s. The simulation studies presented here show that the enzyme possesses a remarkable ability to efficiently utilize its hybrid structure, assuming structurally different peroxidase-like and P450-like distal pocket faces and thereby enhancing the inherent catalytic capability of the active center. We find that during epoxidation of cis-β-methylstyrene (CBMS), the native peroxidase-like aspect of the distal pocket is diminished as the polar Glu183 side chain is displaced away from the active center and the distal pocket takes on a more hydrophobic, P450-like, aspect. The P450-like distal pocket provides a significant enthalpic stabilization of ~4 kcal/mol of the 14 kcal/mol reaction barrier for gas-phase epoxidation of CMBS by an oxyferryl heme-thiolate species. This stabilization comes from breathing of the distal pocket. As until recently the active site of chloroperoxidase was postulated to be inflexible, these results suggest a new conceptual understanding of the enzyme’s versatility: catalytic reactivity is tuned by flexibility of the distal pocket. PMID:23020548

  7. Bilateral en-masse distalization of maxillary posterior teeth with skeletal anchorage: a case report

    PubMed Central

    Noorollahian, Saeed; Alavi, Shiva; Shirban, Farinaz

    2016-01-01

    ABSTRACT Objective: The aim of this study was to introduce a new method for bilateral distal movement of the entire maxillary posterior segment. Case report: A 17-year-old girl with Class I skeletal malocclusion (end-to-end molar relationships, deviated midline and space deficiency for left maxillary canine) was referred for orthodontic treatment. She did not accept maxillary first premolars extraction. A modified Hyrax appliance (Dentaurum Ispringen, Germany) was used for bilateral distalization of maxillary posterior teeth simultaneously. Expansion vector was set anteroposteriorly. Posterior legs of Hyrax were welded to first maxillary molar bands. All posterior teeth on each side consolidated with a segment of 0.017 × 0.025-in stainless steel wire from the buccal side. Anterior legs of Hyrax were bent into eyelet form and attached to the anterior palate with two mini-screws (2 × 10 mm) (Jeil Medical Corporation Seoul, South Korea). Hyrax opening rate was 0.8 mm per month. Lateral cephalometric radiographs were used to evaluate the extent of distal movement. 3.5-mm distalization of posterior maxillary teeth was achieved in five months. Results: A nearly bodily distal movement without anchorage loss was obtained. Conclusion: The mini-screw-supported modified Hyrax appliance was found to be helpful for achieving en-masse distal movement of maxillary posterior teeth. PMID:27409657

  8. Treatment of a Complex Distal Triceps Tendon Rupture With a New Technique: A Case Report

    PubMed Central

    Aunon-Martin, Ismael; Prada-Canizares, Alfonso; Jimenez-Diaz, Veronica; Vidal-Bujanda, Carlos; Leon-Baltasar, Jose Luis

    2016-01-01

    Introduction: The distal triceps tendon rupture is an uncommon injury. The acute treatment is well-defined, but when a delayed diagnosis is made or when a tendon retraction is present the alternatives or reconstruction are limited and sometimes complex. Case Presentation: In this case, we report on a 28-year-old man who presented with a chronic disruption of the distal triceps tendon with a gap of approximately 15 cm. The patient was diagnosed in another center with an inveterate breakage of the distal triceps tendon and was initially treated with an Achilles allograft that was complicated by a wound infection and required more than ten surgeries. Nearly 22 months after the initial trauma, and 12 months after the first surgery, we performed a reconstruction with an Achilles tendon allograft using the new technique of distal attachment. At the 12-month follow-up the patient presented a joint balance from -5º to 110º and presented with no pain. Conclusions: The use of an Achilles tendon allograft provides excellent results in complex distal triceps tendon ruptures. We report the use of a new technique to anchor a distal Achilles allograft. PMID:27148500

  9. Treatment effects of mandibular total arch distalization using a ramal plate

    PubMed Central

    Yu, Jonghan; Park, Jae Hyun; Bayome, Mohamed; Kim, Sungkon; Kook, Yoon-Ah; Kim, Yoonji

    2016-01-01

    Objective The purpose of this study was to evaluate treatment effects after distalization of the mandibular dentition using ramal plates through lateral cephalograms. Methods Pre- and post-treatment lateral cephalograms and dental casts of 22 adult patients (11 males and 11 females; mean age, 23.9 ± 5.52 years) who received ramal plates for mandibular molar distalization were analyzed. The treatment effects and amount of distalization of the mandibular molars were calculated and tested for statistical significance. The significance level was set at p < 0.001. Results The mandibular first molar distalization at the crown and root were 2.10 mm (p < 0.001) and 0.81 mm (p = 0.011), respectively. In the evaluation of skeletal variables, there was a significant increase in the Wits appraisal (p < 0.001). In the evaluation of the soft tissue, there was no significant effect on upper lip position, but the lower lips showed a significant retraction of 2.2 mm (p < 0.001). Conclusions The mandibular molars showed a significant amount of distalization accompanied by limited extrusion and mesiobuccal rotation of the crowns. A ramal plate may be a viable device for mandibular total arch distalization in Class III patients who are reluctant to undergo orthognathic surgery. PMID:27478798

  10. Factors determining the efficacy of distal excitatory synapses in rat hippocampal CA1 pyramidal neurones

    PubMed Central

    Andreasen, Mogens; Lambert, John D C

    1998-01-01

    A new preparation of the in vitro rat hippocampal slice has been developed in which the synaptic input to the distal apical dendrites of CA1 pyramidal neurones is isolated. This has been used to investigate the properties of distally evoked synaptic potentials.Distal paired-pulse stimulation (0.1 Hz) evoked a dendritic response consisting of a pair of EPSPs, which showed facilitation. The first EPSP had a rise time (10–90 %) of 2.2 ± 0.05 ms and a half-width of 9.1 ± 0.13 ms. The EPSPs were greatly reduced by CNQX (10 μm) and the remaining component could be enhanced in Mg2+-free Ringer solution and blocked by AP5 (50 μm). In 70 % of the dendrites, the EPSPs were followed by a prolonged after-hyperpolarizarion (AHP) which could be blocked by a selective and potent GABAB antagonist, CGP 55845A (2 μm). These results indicate that the EPSPs are primarily mediated by non-NMDA receptors with a small contribution from NMDA receptors, whereas the AHP is a GABAB receptor-mediated slow IPSP.With intrasomatic recordings, the rise time of proximally generated EPSPs (3.4 ± 0.1 ms) was half that of distally generated EPSPs (6.7 ± 0.5 ms), whereas the half-widths were similar (19.6 ± 0.8 ms and 23.8 ± 1 ms, respectively). These results indicate that propagation through the proximal apical dendrites slows the time-to-peak of distally generated EPSPs.Distal stimulation evoked spikes in 60 % of pyramidal neurones. At threshold, the distally evoked spike always appeared on the decaying phase of the dendritic EPSP, indicating that the spike is initiated at some distance proximal to the dendritic recording site. Furthermore, distally and proximally generated threshold spikes had a similar voltage dependency. These results therefore suggest that distally generated threshold spikes are primarily initiated at the initial segment.At threshold, spikes generated by stimulation of distal synapses arose from the decaying phase of the dendritic EPSPs with a latency determined by the

  11. Port-site metastasis as a primary complication following retroperitoneal laparoscopic radical resection of renal pelvis carcinoma or nephron-sparing surgery: A report of three cases and review of the literature

    PubMed Central

    WANG, NING; WANG, KAI; ZHONG, DACHUAN; LIU, XIA; SUN, JI; LIN, LIANXIANG; GE, LINNA; YANG, BO

    2016-01-01

    The present study reports the clinical data of two patients with renal pelvis carcinoma and one patient with renal carcinoma who developed port-site metastasis following retroperitoneal laparoscopic surgery. The current study aimed to identify the cause and prognosis of the occurrence of port-site metastasis subsequent to laparoscopic radical resection of renal pelvis carcinoma and nephron-sparing surgery. Post-operative pathology confirmed the presence of high-grade urothelial cell carcinoma in two patients and Fuhrman grade 3 renal clear cell carcinoma in one patient. Port-site metastasis was initially detected 1–7 months post-surgery. The two patients with renal pelvis carcinoma succumbed to the disease 2 and 4 months following the identification of the port-site metastasis, respectively, whereas the patient with renal carcinoma survived with no disease progression during the targeted therapy period. The occurrence of port-site metastasis may be attributed to systemic and local factors. Measures to reduce the development of this complication include strict compliance with the operating guidelines for tumor surgery, avoidance of air leakage at the port-site, complete removal of the specimen with an impermeable bag, irrigation of the laparoscopic instruments and incisional wound with povidone-iodine when necessary, and enhancement of the body's immunity. Close post-operative follow-up observation for signs of recurrence or metastasis is essential, and systemic chemotherapy may be required in patients with high-grade renal pelvis carcinoma and renal carcinoma in order to prolong life expectancy. PMID:27313720

  12. Distinct afferent innervation patterns within the human proximal and distal esophageal mucosa.

    PubMed

    Woodland, Philip; Aktar, Rubina; Mthunzi, Engelbert; Lee, Chung; Peiris, Madusha; Preston, Sean L; Blackshaw, L Ashley; Sifrim, Daniel

    2015-03-15

    Little is known about the mucosal phenotype of the proximal human esophagus. There is evidence to suggest that the proximal esophagus is more sensitive to chemical and mechanical stimulation compared with the distal. This may have physiological relevance (e.g., in prevention of aspiration of gastroesophageal refluxate), but also pathological relevance (e.g., in reflux perception or dysphagia). Reasons for this increased sensitivity are unclear but may include impairment in mucosal barrier integrity or changes in sensory innervation. We assessed mucosal barrier integrity and afferent nerve distribution in the proximal and distal esophagus of healthy human volunteers. In 10 healthy volunteers baseline proximal and distal esophageal impedance was measured in vivo. Esophageal mucosal biopsies from the distal and proximal esophagus were taken, and baseline transepithelial electrical resistance (TER) was measured in Ussing chambers. Biopsies were examined immunohistochemically for presence and location of calcitonin gene-related peptide (CGRP)-immunoreactive nerve fibers. In a further four healthy volunteers we investigated for colocalization of CGRP and protein gene product (PGP) 9.5 immunoreactivity in nerve fibers. Baseline impedance was higher in the proximal than in the distal esophagus [2,936 Ω (SD578) vs. 2,229 Ω (SD821); P = 0.03], however, baseline TER was not significantly different between them. Mucosal CGRP-immunoreactive nerves were found in the epithelium of both proximal and distal esophagus, but were located more superficially in the proximal mucosa compared with the distal [11.5 (SD7) vs. 21.7 (SD5) cell layers from lumen, P = 0.002] 19% of proximal, and 10% of distal mucosal PGP-immunoreactive fibers colocalized with CGRP. PGP-immunoreactive fibers were also significantly closer to the luminal surface in the proximal compared with the distal esophagus (P < 0.001). We conclude that mucosal barrier integrity is similar in proximal and distal esophagus

  13. Role of Rho GDP dissociation inhibitor α in control of epithelial sodium channel (ENaC)-mediated sodium reabsorption.

    PubMed

    Pavlov, Tengis S; Levchenko, Vladislav; Staruschenko, Alexander

    2014-10-10

    The epithelial sodium channel (ENaC) is expressed in the aldosterone-sensitive distal nephron where it performs sodium reabsorption from the lumen. We have recently shown that ENaC activity contributes to the development of salt-induced hypertension as a result of deficiency of EGF level. Previous studies revealed that Rho GDP-dissociation inhibitor α (RhoGDIα) is involved in the control of salt-sensitive hypertension and renal injury via Rac1, which is one of the small GTPases activating ENaC. Here we investigated the intracellular mechanism mediating the involvement of the RhoGDIα/Rac1 axis in the control of ENaC and the effect of EGF on ENaC in this pathway. We demonstrated that RhoGDIα is highly expressed in the cortical collecting ducts of mice and rats, and its expression is down-regulated in Dahl salt-sensitive rats fed a high salt diet. Knockdown of RhoGDIα in cultured cortical collecting duct principal cells increased ENaC subunits expression and ENaC-mediated sodium reabsorption. Furthermore, RhoGDIα deficiency causes enhanced response to EGF treatment. Patch clamp analysis reveals that RhoGDIα significantly decreases ENaC current density and prevents its up-regulation by RhoA and Rac1. Inhibition of Rho kinase with Y27632 had no effects on ENaC response to EGF either in control or RhoGDIα knocked down cells. However, EGF treatment increased levels of active Rac1, which was further enhanced in RhoGDIα-deficient cells. We conclude that changes in the RhoGDIα-dependent pathway have a permissive role in the Rac1-mediated enhancement of ENaC activity observed in salt-induced hypertension.

  14. Preservation of peripheral benzodiazepine receptors: differential effects of freezing on (/sup 3/H)Ro 5-4864 and (3H)PK 11195 binding

    SciTech Connect

    Basile, A.S.; Ostrowski, N.L.; Skolnick, P.

    1987-04-01

    A statistically significant decrease in the density of peripheral benzodiazepine receptors was observed in renal membranes of rats beginning 2 weeks after adrenalectomy when compared with sham-operated controls. This decrease in peripheral benzodiazepine receptor density was manifest as a decrease in the Bmax of two ligands (/sup 3/H)Ro 5-4864 and (/sup 3/H)PK 11195, without accompanying changes in their apparent affinity (Kd) for this site. Similar changes were not seen in another aldosterone-sensitive organ, the submandibular salivary gland. The decrease in peripheral benzodiazepine receptor density in observed in adrenalectomized rat renal membranes was restored to control levels after 1 week of aldosterone administration using a dose (12.5 micrograms/kg/day) that had no effect on peripheral benzodiazepine receptor density in sham-operated animals. In contrast, dexamethasone administration (50 micrograms/kg/day, 1 week) had no effect on renal peripheral benzodiazepine receptor density when administered to either adrenalectomized or sham-operated rats. Further, adrenal demedullation had no effect on renal peripheral benzodiazepine receptor density or affinity. The decrease in peripheral benzodiazepine receptor density was localized to the renal cortex and the outer stripe of the medulla by gross dissection of renal slices and renal tissue section autoradiography. The specific effect of adrenalectomy on renal peripheral benzodiazepine receptor density, the lack of direct effect of aldosterone on (/sup 3/H)Ro 5-4864 binding, and the localization of the change in peripheral benzodiazepine receptor density to the renal cortex and outer stripe suggests that these changes may reflect an adaptation of the renal nephron (possibly the distal convoluted tubule, intermediate tubule and/or the collecting duct) to the loss of mineralocorticoid hormones.

  15. Aldosterone-reversible decrease in the density of renal peripheral benzodiazepine receptors in the rat after adrenalectomy

    SciTech Connect

    Basile, A.S.; Ostrowski, N.L.; Skolnick, P.

    1987-03-01

    A statistically significant decrease in the density of peripheral benzodiazepine receptors was observed in renal membranes of rats beginning 2 weeks after adrenalectomy when compared with sham-operated controls. This decrease in peripheral benzodiazepine receptor density was manifest as a decrease in the maximum binding of two ligands, (/sup 3/H)Ro 5-4864 and (/sup 3/H)PK 11195, without accompanying changes in their Kd for this site. Similar changes were not seen in another aldosterone-sensitive organ, the submandibular salivary gland. The decrease in peripheral benzodiazepine receptor density observed in adrenalectomized rat renal membranes was restored to control levels after 1 week of aldosterone administration using a dose (12.5 micrograms/kg/day) that had no effect on peripheral benzodiazepine receptor density in sham-operated animals. In contrast, dexamethasone administration (50 micrograms/kg/day, 1 week) had no effect on renal peripheral benzodiazepine receptor density when administered to either adrenalectomized or sham-operated rats. Further, adrenal demedullation had no effect on renal peripheral benzodiazepine receptor density or affinity. The decrease in peripheral benzodiazepine receptor density was localized to the renal cortex and the outer stripe of the medulla by gross dissection of renal slices and renal tissue section autoradiography. The specific effect of adrenalectomy on renal peripheral benzodiazepine receptor density, the lack of direct effect of aldosterone on (/sup 3/H) Ro 5-4864 binding and the localization of the change in peripheral benzodiazepine receptor density to the renal cortex and outer stripe suggest that these changes may reflect an adaptation of the renal nephron (possibly the distal convoluted tubule, intermediate tubule and/or the collecting duct) to the loss of mineralocorticoid hormones.

  16. Diminished Paracrine Regulation of the Epithelial Na+ Channel by Purinergic Signaling in Mice Lacking Connexin 30*

    PubMed Central

    Mironova, Elena; Peti-Peterdi, Janos; Bugaj, Vladislav; Stockand, James D.

    2011-01-01

    We tested whether ATP release through Connexin 30 (Cx30) is part of a local purinergic regulatory system intrinsic to the aldosterone-sensitive distal nephron (ASDN) important for proper control of sodium excretion; if changes in sodium intake influence ATP release via Cx30; and if this allows a normal ENaC response to changes in systemic sodium levels. In addition, we define the consequences of disrupting ATP regulation of ENaC in Cx30−/− mice. Urinary ATP levels in wild-type mice increase with sodium intake, being lower and less dependent on sodium intake in Cx30−/− mice. Loss of inhibitory ATP regulation causes ENaC activity to be greater in Cx30−/− versus wild-type mice, particularly with high sodium intake. This results from compromised ATP release rather than end-organ resistance: ENaC in Cx30−/− mice responds to exogenous ATP. Thus, loss of paracrine ATP feedback regulation of ENaC in Cx30−/− mice disrupts normal responses to changes in sodium intake. Consequently, ENaC is hyperactive in Cx30−/− mice lowering sodium excretion particularly during increases in sodium intake. Clamping mineralocorticoids high in Cx30−/− mice fed a high sodium diet causes a marked decline in renal sodium excretion. This is not the case in wild-type mice, which are capable of undergoing aldosterone-escape. This loss of the ability of ENaC to respond to changes in sodium levels contributes to salt-sensitive hypertension in Cx30−/− mice. PMID:21075848

  17. Diminished paracrine regulation of the epithelial Na+ channel by purinergic signaling in mice lacking connexin 30.

    PubMed

    Mironova, Elena; Peti-Peterdi, Janos; Bugaj, Vladislav; Stockand, James D

    2011-01-14

    We tested whether ATP release through Connexin 30 (Cx30) is part of a local purinergic regulatory system intrinsic to the aldosterone-sensitive distal nephron (ASDN) important for proper control of sodium excretion; if changes in sodium intake influence ATP release via Cx30; and if this allows a normal ENaC response to changes in systemic sodium levels. In addition, we define the consequences of disrupting ATP regulation of ENaC in Cx30(-/-) mice. Urinary ATP levels in wild-type mice increase with sodium intake, being lower and less dependent on sodium intake in Cx30(-/-) mice. Loss of inhibitory ATP regulation causes ENaC activity to be greater in Cx30(-/-) versus wild-type mice, particularly with high sodium intake. This results from compromised ATP release rather than end-organ resistance: ENaC in Cx30(-/-) mice responds to exogenous ATP. Thus, loss of paracrine ATP feedback regulation of ENaC in Cx30(-/-) mice disrupts normal responses to changes in sodium intake. Consequently, ENaC is hyperactive in Cx30(-/-) mice lowering sodium excretion particularly during increases in sodium intake. Clamping mineralocorticoids high in Cx30(-/-) mice fed a high sodium diet causes a marked decline in renal sodium excretion. This is not the case in wild-type mice, which are capable of undergoing aldosterone-escape. This loss of the ability of ENaC to respond to changes in sodium levels contributes to salt-sensitive hypertension in Cx30(-/-) mice.

  18. Osteopathology in the Equine Distal Phalanx Associated With the Development and Progression of Laminitis.

    PubMed

    Engiles, J B; Galantino-Homer, H L; Boston, R; McDonald, D; Dishowitz, M; Hankenson, K D

    2015-09-01

    Although the equine distal phalanx and hoof lamellae are biomechanically and physiologically integrated, bony changes in the distal phalanx are poorly described in laminitis. The aims of this study were (1) to establish a laminitis grading scheme that can be applied to the wide spectrum of lesions seen in naturally occurring cases and (2) to measure and describe changes in the distal phalanx associated with laminitis using micro-computed tomography (micro-CT) and histology. Thirty-six laminitic and normal feet from 15 performance and nonperformance horses were evaluated. A laminitis grading scheme based on radiographic, gross, histopathologic, and temporal parameters was developed. Laminitis severity grades generated by this scheme correlated well with clinical severity and coincided with decreased distal phalanx bone volume and density as measured by micro-CT. Laminitic hoof wall changes included progressive ventral rotation and distal displacement of the distal phalanx with increased thickness of the stratum internum-corium tissues with lamellar wedge formation. Histologically, there was epidermal lamellar necrosis with basement membrane separation and dysplastic regeneration, including acanthosis and hyperkeratosis, corresponding to the lamellar wedge. The changes detected by micro-CT corresponded to microscopic findings in the bone, including osteoclastic osteolysis of trabecular and osteonal bone with medullary inflammation and fibrosis. Bone changes were identified in horses with mild/early stages of laminitis as well as severe/chronic stages. The authors conclude that distal phalangeal pathology is a quantifiable and significant component of laminitis pathology and may have important implications for early detection or therapeutic intervention of equine laminitis.

  19. Comparison of K-loop Molar Distalization with that of Pendulum Appliance - A Prospective Comparative Study

    PubMed Central

    Shashidhar, Nagam Reddy; Reddy, S.Rama Koteswara

    2016-01-01

    Introduction Molar distalization is the non extraction method of managing Class II malocclusions. Aim The purpose of this study was to evaluate the skeletal and dentoalveolar effects of maxillary molar distalization with K-loop appliance, and to compare these effects with that of pendulum group. Materials and Methods Class I and dental Class II malocclusions were divided into two groups of 15 each: In Group 1 (nine females and six males; mean age, 16.0±2.6 years) patients were treated with K-Loop molar distalization supported palatally by Nance button, while in Group 2 (seven females and eight males; mean age, 15.4±4.7 years), the patients were treated with conventional pendulum appliance. Standardized lateral cephalograms were taken at the beginning of treatment (T0) and at the end of molar distalization (T1) and the changes were statistically analyzed with paired t-test. Results The results showed no statistically significant difference in the amount of molar distalization in either of the appliance groups: the mean amount of molar distal movement of 5.1±0.8 mm and 4.93±1.68 mm was observed in the Group 1 and 2 respectively. The incisors moved mesially by 1.3±0.63 mm in Group 1 and 1.57±0.58 mm in Group 2. Conclusion K-Loop molar distalizing appliance has similar skeletal and dentoalveolar effects as that of pendulum appliance, with the advantages of simple yet efficient to control the moment-force ratio to produce all types of tooth movements and also requires minimal patient co-operation. PMID:27504403

  20. Growth arrest of the distal radius following a metaphyseal fracture: case report and review of the literature.

    PubMed

    Tang, Chris W; Kay, Robert M; Skaggs, David L

    2002-01-01

    We report a 12-year-old girl who developed growth arrest of the distal radius physis 9 months after sustaining a complete fracture of the distal radial and ulnar metaphysis with no involvement of the physis evident at time of injury. The girl sustained a fracture of the metaphysis of her right distal radius and ulna after a fall. Anterior-posterior, lateral and oblique radiographs at injury, and during subsequent healing show no evidence of the fracture involving the physis. She was treated with closed reduction and casting for 6 weeks and healed uneventfully. She returned 4 month later concerned about distal ulnar prominence. Radiographs revealed a loss of radial tilt and with suspicion of a physeal bar. Magnetic resonance imaging confirmed a physeal bar located in the dorsal radial region. A literature search of the Medline database was used to obtain prior case reports for review purpose. The patient underwent an epiphysiodesis of the distal radius and ulna along with an opening wedge osteotomy and bone grafting of the distal radius to restore radial height and inclination. She healed without complication and with restoration of the normal relationship of the distal radius and ulna. A review of the literature reveals five reported case of distal radial metaphyseal fractures not invloving the physis leading to growth arrest. By comparison, there are 31 reported cases of distal radius physeal arrest following fractures involving the physis. The physician should be aware that common distal radius metaphyseal fractures may rarely lead to growth arrest.

  1. Laparoscopic distal splenoadrenal shunt for the treatment of portal hypertension in children with congenital hepatic fibrosis

    PubMed Central

    Zhang, Jin-Shan; Cheng, Wei; Li, Long

    2017-01-01

    Abstract Background: The distal splenorenal shunt is an effective procedure for the treatment of portal hypertension in children. However, there has been no report about laparoscopic distal splenorenal shunt in the treatment of portal hypertension in children. Methods: From December 2015 to August 2016, 4 children with upper gastrointestinal bleeding underwent laparoscopic distal splenoadrenal shunt. Portal hypertension and splenomegaly were demonstrated on the preoperative computed tomography (CT) and sonography. The distal splenic vein was mobilized and anastomosed to the left adrenal vein laparoscopically. All patients were followed-up postoperatively. Results: The laparoscopic distal splenoadrenal shunt was successfully performed in all patients. The liver fibrosis was diagnosed by postoperative liver pathology. The operative time ranged from 180 to 360 minutes. The blood loss was minimal. The length of hospital stay was 6 to 13 days. The duration of following-up was 1 to 9 months (median: 3 months). The portal pressure and splenic size were decreased postoperatively. The complete blood count normalized and the biochemistry tests were within normal range after surgery. Postoperative ultrasound and CT confirmed shunt patency and satisfactory flow in the splenoadrenal shunt in all patients. No patient developed recurrence of variceal bleeding. Conclusions: The laparoscopic splenoadrenal shunt is a feasible treatment of portal hypertension in children. PMID:28099341

  2. Expression of arthropod distal limb-patterning genes in the onychophoran Euperipatoides kanangrensis.

    PubMed

    Oliveira, Marta Bastos; Liedholm, Simon Eckerström; Lopez, Jordi Estefa; Lochte, Annalena A; Pazio, Magdalena; Martin, Jesus Pena; Mörch, Patrik Rödin; Salakka, Seela; York, Julia; Yoshimoto, Andrew; Janssen, Ralf

    2014-03-01

    A current hypothesis states that the ancestral limb of arthropods is composed of only two segments. The proximal segment represents the main part of the modern leg, and the distal segment represents the tarsus and claw of the modern leg. If the distal part of the limb is an ancestral feature, one would expect conserved regulatory gene networks acting in distal limb development in all arthropods and possibly even their sister group, the onychophorans. We investigated the expression patterns of six genes known to function during insect distal limb development in the onychophoran Euperipatoides kanangrensis, i.e., clawless (cll), aristaless (al), spineless (ss), zinc finger homeodomain 2 (zfh2), rotund (rn), and Lim1. We find that all investigated genes are expressed in at least some of the onychophoran limbs. The expression patterns of most of these genes, however, display crucial differences to the known insect patterns. The results of this study question the hypothesis of conserved distal limb evolution in arthropods and highlight the need for further studies on arthropod limb development.

  3. Risk factors associated with distal catheter migration following ventriculoperitoneal shunt placement.

    PubMed

    Abode-Iyamah, Kingsley O; Khanna, Ryan; Rasmussen, Zachary D; Flouty, Oliver; Dahdaleh, Nader S; Greenlee, Jeremy; Howard, Matthew A

    2016-03-01

    Ventriculoperitoneal (VP) shunt placement is used to treat hydrocephalus. Shunt migration following VP shunt placement has been reported. The risk factors related to this complication have not been previously evaluated to our knowledge. In this retrospective cohort study, we aimed to determine risk factors leading to distal catheter migration and review the literature on the current methods of management and prevention. Adult patients undergoing VP shunt placement from June 2011 to December 2013 at a single institution were identified using electronic health records. The records were reviewed for demographic and procedural information, and subsequent treatment characteristics. The parameters of patients with distal shunt migration were compared to those undergoing new VP shunt placement for the same time period. We identified 137 patients undergoing 157 new VP shunt procedures with an average age of 57.7 ± standard deviation of 18.4 years old. There were 16 distal shunt migrations. Body mass index >30 kg/m(2) and number of previous shunt procedures were found to be independent risk factors for distal catheter migration. Obesity and number of previous shunt procedures were factors for distal catheter migration. Providers and patients should be aware of these possible risk factors prior to VP shunt placement.

  4. Imaging appearance of entrapped periosteum within a distal femoral Salter-Harris II fracture.

    PubMed

    Chen, Johnathan; Abel, Mark F; Fox, Michael G

    2015-10-01

    Salter Harris II fractures of the distal femur are associated with a high incidence of complications, especially premature physeal closure. Many risk factors for this high rate of premature physeal closure have been proposed. More recently, entrapment of periosteum within the physis has been suggested as an additional predisposing factor for premature physeal closure. The radiographic diagnosis of entrapped soft tissues, including periosteum, can be suggested in the setting of a Salter-Harris II fracture when the fracture does not reduce and physeal widening >3 mm remains. We report a patient who sustained a distal femoral Salter-Harris II fracture following a valgus injury. The patient had persistent distal medial physeal widening >5 mm following attempted reduction. A subsequent MRI revealed a torn periosteum entrapped within the distal femoral physis. Following removal of the periosteum, the patient developed a leg length discrepancy which required physiodesis of the contralateral distal femur. We present this case to raise awareness of the importance of having a high index of suspicion of periosteal entrapment in the setting of Salter-Harris II fractures since most consider entrapped periosteum an indication for surgery.

  5. SQSTM1 splice site mutation in distal myopathy with rimmed vacuoles

    PubMed Central

    Bucelli, Robert C.; Arhzaouy, Khalid; Pestronk, Alan; Pittman, Sara K.; Rojas, Luisa; Sue, Carolyn M.; Evilä, Anni; Hackman, Peter; Udd, Bjarne; Harms, Matthew B.

    2015-01-01

    Objective: To identify the genetic etiology and characterize the clinicopathologic features of a novel distal myopathy. Methods: We performed whole-exome sequencing on a family with an autosomal dominant distal myopathy and targeted exome sequencing in 1 patient with sporadic distal myopathy, both with rimmed vacuolar pathology. We also evaluated the pathogenicity of identified mutations using immunohistochemistry, Western blot analysis, and expression studies. Results: Sequencing identified a likely pathogenic c.1165+1 G>A splice donor variant in SQSTM1 in the affected members of 1 family and in an unrelated patient with sporadic distal myopathy. Affected patients had late-onset distal lower extremity weakness, myopathic features on EMG, and muscle pathology demonstrating rimmed vacuoles with both TAR DNA-binding protein 43 and SQSTM1 inclusions. The c.1165+1 G>A SQSTM1 variant results in the expression of 2 alternatively spliced SQSTM1 proteins: 1 lacking the C-terminal PEST2 domain and another lacking the C-terminal ubiquitin-associated (UBA) domain, both of which have distinct patterns of cellular and skeletal muscle localization. Conclusions: SQSTM1 is an autophagic adaptor that shuttles aggregated and ubiquitinated proteins to the autophagosome for degradation via its C-terminal UBA domain. Similar to mutations in VCP, dominantly inherited mutations in SQSTM1 are now associated with rimmed vacuolar myopathy, Paget disease of bone, amyotrophic lateral sclerosis, and frontotemporal dementia. Our data further suggest a pathogenic connection between the disparate phenotypes. PMID:26208961

  6. The persistence of epiphyseal scars in the distal radius in adult individuals.

    PubMed

    Davies, Catriona; Hackman, Lucina; Black, Sue

    2016-01-01

    The use of radiographic imaging in the estimation of chronological age facilitates the analysis of structures not visible on gross morphological inspection. Following the completion of epiphyseal fusion, a thin radio-opaque band, the epiphyseal scar, may be observed at the locus of the former growth plate. The obliteration of this feature has previously been interpreted as the final stage of skeletal maturation and consequently has been included as a criterion in several methods of age estimation, particularly from the distal radius. Due to the recommendations relating to age estimation in living individuals, accurate assessment of age from the distal radius is of great importance in human identification; however, the validity of the interpretation of the obliteration of the epiphyseal scar as an age-related process has not been tested. A study was undertaken to assess the persistence of epiphyseal scars in adults between 20 and 50 years of age through the assessment of 616 radiographs of left and right distal radii from a cross-sectional population. This study found that 86% of females and 78% of males retained some remnant of the epiphyseal scar in the distal radius. The relationships between chronological age, biological sex and the persistence of the epiphyseal scar were not statistically significant. The findings of this study indicate that the epiphyseal scars may persist in adult individuals until at least 50 years of age. No maximum age should therefore be applied to the persistence of an epiphyseal scar in the distal radius.

  7. Corrective distal radius osteotomy: including bilateral differences in 3-D planning.

    PubMed

    Dobbe, J G G; Vroemen, J C; Strackee, S D; Streekstra, G J

    2013-07-01

    After a fracture of the distal radius, the bone segments may heal in a suboptimal position. This condition may lead to a reduced hand function, pain and finally osteoarthritis, sometimes requiring corrective surgery. Recent studies report computer-assisted 3-D planning techniques in which the mirrored contralateral unaffected radius serves as reference for planning the position of the distal radius before corrective osteotomy surgery. Bilateral asymmetry, however, may introduce length errors into this type of preoperative planning that can be compensated for by taking into account the concomitant ulnae asymmetry. This article investigates a method for planning a correction osteotomy of the distal radius, while compensating for bilateral length differences using a linear regression model that describes the relationship between radii and ulnae asymmetry. The method is evaluated quantitatively using CT scans of 20 healthy individuals, and qualitatively using CT scans of patients suffering from a malunion of the distal radius. The improved planning method reduces absolute length deviations by a factor of two and markedly reduces positioning variation, from 2.9 ± 2.1 to 1.5 ± 0.6 mm. We expect the method to be of great value for future 3-D planning of a corrective distal radius osteotomy.

  8. Functional association between proximal and distal gastric motility during fasting and duodenal nutrient stimulation in humans.

    PubMed

    Nguyen, N Q; Fraser, R J; Bryant, L K; Holloway, R H

    2007-08-01

    A functional integration exists between proximal and distal gastric motor activity in dogs but has not been demonstrated in humans. To determine the relationship between proximal and distal gastric motor activity in humans. Concurrent proximal (barostat) and distal (antro-pyloro-duodenal (APD) manometry) gastric motility were recorded in 10 healthy volunteers (28 +/- 3 years) during (i) fasting and (ii) two 60-min duodenal infusions of Ensure((R)) (1 and 2 kcal min(-1)) in random order. Proximal and APD motor activity and the association between fundic and propagated antral waves (PAWs) were determined. During fasting, 32% of fundic waves (FWs) were followed by a PAW. In a dose-dependent fashion, duodenal nutrients (i) increased proximal gastric volume, (ii) reduced fundic and antral wave (total and propagated) activity, and (iii) increased pyloric contractions. The proportion of FWs followed by a distal PAW was similar between both infusions and did not differ from fasting. During nutrient infusion, nearly all PAWs were antegrade, propagated over a shorter distance and less likely to traverse the pylorus, compared with fasting. In humans, a functional association exists between proximal and distal gastric motility during fasting and duodenal nutrient stimulation. This may have a role in optimizing intra-gastric meal distribution.

  9. Anterolateral Versus Medial Plating of Distal Extra-articular Tibia Fractures: A Biomechanical Model.

    PubMed

    Pirolo, Joseph M; Behn, Anthony W; Abrams, Geoffrey D; Bishop, Julius A

    2015-09-01

    Both medial and anterolateral plate applications have been described for the treatment of distal tibia fractures, each with distinct advantages and disadvantages. The objective of this study was to compare the biomechanical properties of medial and anterolateral plating constructs used to stabilize simulated varus and valgus fracture patterns of the distal tibia. In 16 synthetic tibia models, a 45° oblique cut was made to model an Orthopedic Trauma Association type 43-A1.2 distal tibia fracture in either a varus or valgus injury pattern. Each fracture was then reduced and plated with a precontoured medial or anterolateral distal tibia plate. The specimens were biomechanically tested in axial and torsional loading, cyclic axial loading, and load to failure. For the varus fracture pattern, medial plating showed less fracture site displacement and rotation and was stiffer in both axial and torsional loading (P<.05). For the valgus fracture pattern, there was no statistically significant difference between medial and anterolateral plating. There were no significant differences between the 2 constructs for either fracture pattern with respect to ultimate load, displacement, or energy absorption in load to failure testing. When used to stabilize varus fracture patterns, medial plates showed superior biomechanical performance compared with anterolateral plates. In this application, the medial plates functioned in anti-glide mode. For valgus fracture patterns, no biomechanical differences between anterolateral and medial plating were observed. In clinical practice, surgeons should take this biomechanical evidence into account when devising a treatment strategy for fixation of distal tibia fractures.

  10. Wls-mediated Wnts differentially regulate distal limb patterning and tissue morphogenesis.

    PubMed

    Zhu, Xuming; Zhu, Huang; Zhang, Lingling; Huang, Sixia; Cao, Jingjing; Ma, Gang; Feng, Guoying; He, Lin; Yang, Yingzi; Guo, Xizhi

    2012-05-15

    Wnt proteins are diffusible morphogens that play multiple roles during vertebrate limb development. However, the complexity of Wnt signaling cascades and their overlapping expression prevent us from dissecting their function in limb patterning and tissue morphogenesis. Depletion of the Wntless (Wls) gene, which is required for the secretion of various Wnts, makes it possible to genetically dissect the overall effect of Wnts in limb development. In this study, the Wls gene was conditionally depleted in limb mesenchyme and ectoderm. The loss of mesenchymal Wls prevented the differentiation of distal mesenchyme and arrested limb outgrowth, most likely by affecting Wnt5a function. Meanwhile, the deletion of ectodermal Wls resulted in agenesis of distal limb tissue and premature regression of the distal mesenchyme. These observations suggested that Wnts from the two germ layers differentially regulate the pool of undifferentiated distal limb mesenchyme cells. Cellular behavior analysis revealed that ectodermal Wnts sustain mesenchymal cell proliferation and survival in a manner distinct from Fgf. Ectodermal Wnts were also shown for the first time to be essential for distal tendon/ligament induction, myoblast migration and dermis formation in the limb. These findings provide a comprehensive view of the role of Wnts in limb patterning and tissue morphogenesis.

  11. Palatal implant versus zygoma plate anchorage for distalization of maxillary posterior teeth.

    PubMed

    Kaya, Burçak; Sar, Cagla; Arman-Özçirpici, Ayça; Polat-Özsoy, Omür

    2013-08-01

    This study aimed to examine the skeletal, dental, and soft tissue effects of the implant-supported pendulum (ISP) and the zygoma anchorage system (ZAS) used for the distalization of maxillary posterior teeth. Among 30 patients showing Angle class II malocclusion, 15 patients with a mean age of 14.3±1.6 years and treated with ISP were included in the first group; 15 patients with a mean age of 14.7±2.5 years and treated with ZAS were included in the second group. The predistalization and postdistalization lateral cephalograms were analysed. Statistical evaluation was carried out using SPSS. Point A and upper incisors protruded in the ISP group, retruded in the ZAS group. Upper posterior teeth were distalized in both groups, but more in the ZAS group. Significant differences were observed between the groups for the sagittal movements of Point A, incisors, and posterior teeth. Overbite decreased in the ISP group, overjet decreased in the ZAS group, upper and lower lips retruded only in the ZAS group. Both methods provided absolute anchorage for distalization of posterior teeth, but the skeletal and soft tissue outcome and distalization obtained was greater in the ZAS group. Both methods can be used as alternatives to extraoral traction and conventional molar distalization appliances with different patient requirements.

  12. Type IIA Monteggia Fracture Dislocation with Ipsilateral Distal Radius Fracture in Adult – A Rare Association

    PubMed Central

    James, Boblee

    2016-01-01

    Monteggia fracture constitutes about 5-10% of the forearm fractures. Monteggia fracture by definition is proximal ulnar fracture with disruption of proximal radioulnar joint. Bado classified Monteggia fracture dislocation into four types and Jupiter subclassified type II Bado’s fractures into four types. The associated injury in the form of distal radial fractures and distal humerus fractures are rare though many cases of distal radial physeal injuries have been reported in paediatric population. Hereby we report a rare association of type IIA Monteggia fracture dislocation with ipsilateral distal radius fracture in an adult patient. This case report also highlights on proper examination and full length radiographs of forearm to avoid missing injury at wrist in cases of elbow injuries. Management of such complex injuries included open reduction and internal fixation of olecronon fracture, distal radius fracture and radial head resection. Functional outcome at six months was good at wrist whereas at elbow, stiffness was a major concern with elbow range of movement from 40°-110°. PMID:27656518

  13. Effects of the location of distal histidine in the reaction of myoglobin with hydrogen peroxide.

    PubMed

    Matsui, T; Ozaki, S i; Liong, E; Phillips, G N; Watanabe, Y

    1999-01-29

    To clarify how the location of distal histidine affects the activation process of H2O2 by heme proteins, we have characterized reactions with H2O2 for the L29H/H64L and F43H/H64L mutants of sperm whale myoglobin (Mb), designed to locate the histidine farther from the heme iron. Whereas the L29H/H64L double substitution retarded the reaction with H2O2, an 11-fold rate increase versus wild-type Mb was observed for the F43H/H64L mutant. The Vmax values for 1-electron oxidations by the myoglobins correlate well with the varied reactivities with H2O2. The functions of the distal histidine as a general acid-base catalyst were examined based on the reactions with cumene hydroperoxide and cyanide, and only the histidine in F43H/H64L Mb was suggested to facilitate heterolysis of the peroxide bond. The x-ray crystal structures of the mutants confirmed that the distal histidines in F43H/H64L Mb and peroxidase are similar in distance from the heme iron, whereas the distal histidine in L29H/H64L Mb is located too far to enhance heterolysis. Our results indicate that the proper positioning of the distal histidine is essential for the activation of H2O2 by heme enzymes.

  14. Patency of femoropopliteal and femorotibial grafts after outflow revascularization (jump grafts) to bypass distal disease.

    PubMed

    Andros, G; Harris, R W; Dulawa, L B; Oblath, R W; Salles-Cunha, S X

    1984-11-01

    Repair of failing femorodistal bypass grafts with secondary distal "jump" grafts was performed 34 times in 33 patients. Indication for operation was limb salvage for all distal jump grafts and for 85% of the initial femorodistal bypass grafts. Autogenous vein bypass grafts were used in 28 of 33 initial femorodistal grafts (85%) and in 29 of 34 secondary jump grafts (85%). Sixteen of the 33 initial grafts in jeopardy extended to the infrapopliteal level (48%) and 19 of the jump grafts terminated in foot or ankle arteries (56%). The 12 jump grafts performed in the first 2 months of the initial graft were associated with high rates (9%) of graft thrombosis and amputation. Early loss of viability of initial grafts probably resulted from technical and judgment errors or underestimation of distal disease. Progression of distal disease produced late failure after 1 year of implantation of the initial grafts. The 1-year patency rate of the initial femorodistal grafts was 63% but only 32% of these grafted limbs were viable and were not at risk of amputation. Distal jump grafts produced a 49% improvement in limb viability (to an 81% limb salvage rate) and an 11% increase in the initial graft patency rate (to 74%) at 1 year.

  15. Carpal Malalignment in Malunion of the Distal Radius and the Effect of Corrective Osteotomy

    PubMed Central

    De Smet, Luc; Verhaegen, Filip; Degreef, Ilse

    2014-01-01

    Introduction Malunions of the distal radius often induce carpal malalignment. Two different types can be distinguished: an adaptive midcarpal malalignment (so-called CIA wrist: carpal instability, adaptive) and a radiocarpal malalignment (dorsal translation of the whole carpus). The effect of distal radial osteotomy on the carpal alignment has hardly been studied. Material and Methods 31 wrists in 31 patients (mean age 44 years) with malunion of the distal radius after a Colles fracture were treated with a corrective osteotomy. The patients were divided on basis of effective radio-lunate flexion (ERLF) in the two patterns of carpal malalignment. The radiographic changes were evaluated. Results There were 20 patients with midcarpal malalignment (ERLF ≤ 25°) and 11 with radiocarpal malalignment (ERLF > 25°). There was a correction of radial tilt and ulnar variance in both groups. There was a significant improvement of the carpal alignment in the midcarpal malalignment group, up to normal parameters. Neither age nor delay between fracture and osteotomy correlated. In the radiocarpal malalignment group a significant effect on the ERLF was observed. In the patients with dorsal plating 70% of the hardware had to be removed. Conclusion Distal radial osteotomy is a reliable technique for correction of the deformity at the distal end of the radius and carpal malalignment. PMID:25097809

  16. Model-based aviation advice on distal volcanic ash clouds by assimilating aircraft in situ measurements

    NASA Astrophysics Data System (ADS)

    Fu, Guangliang; Heemink, Arnold; Lu, Sha; Segers, Arjo; Weber, Konradin; Lin, Hai-Xiang

    2016-07-01

    The forecast accuracy of distal volcanic ash clouds is important for providing valid aviation advice during volcanic ash eruption. However, because the distal part of volcanic ash plume is far from the volcano, the influence of eruption information on this part becomes rather indirect and uncertain, resulting in inaccurate volcanic ash forecasts in these distal areas. In our approach, we use real-life aircraft in situ observations, measured in the northwestern part of Germany during the 2010 Eyjafjallajökull eruption, in an ensemble-based data assimilation system combined with a volcanic ash transport model to investigate the potential improvement on the forecast accuracy with regard to the distal volcanic ash plume. We show that the error of the analyzed volcanic ash state can be significantly reduced through assimilating real-life in situ measurements. After a continuous assimilation, it is shown that the aviation advice for Germany, the Netherlands and Luxembourg can be significantly improved. We suggest that with suitable aircrafts measuring once per day across the distal volcanic ash plume, the description and prediction of volcanic ash clouds in these areas can be greatly improved.

  17. [About cover of ballistic wounds of distal third of leg in civilian ways].

    PubMed

    Chichery, A; Mojallal, A; Soubirac, L; Breton, P

    2007-12-01

    Major causes of ballistic wounds are shooting accidents. Goals of this work are to suggest a position about ballistic wounds of leg's distal third. Reconstruction of ballistic wounds of leg's distal third is difficult, because of lack of laxity and veinous drainage in distal third; and characteristics of ballistic wounds. Ballistic traumas give a temporary cavity, which induce levelled wounds of neurovascular pedicules. We present three cases. One patient benefits from a sural flap, whereas the two others benefit respectively from a free parascapular flap and a free latissimus dorsi flap with free osseous graft. Functional results were considered as good. Treatment of ballistic wounds ask for certain specificities: 1) meticulous evaluation of wounds; 2) evaluation of vascular axis of leg. Debridments are numerous under general anaesthesia before a reconstruction with axial regional flap or free flap, which vessels are anastomosed distant. Reconstruction must be done before the tenth day.

  18. Standing placement of transphyseal screw in the distal radius in 8 Thoroughbred yearlings

    PubMed Central

    Modesto, Rolf B.; Rodgerson, Dwayne H.; Masciarelli, Amanda E.; Spirito, Michael

    2015-01-01

    This retrospective study describes placement of distal radial transphyseal screws in Thoroughbred yearlings with carpal varus deformities while standing, and identifes short- and long-term complications following the procedure. Data gathered from 2009 to 2013 identified 8 yearlings that met the inclusion criteria. Horses were sedated intravenously and a single 4.5-mm cortical screw was placed in the distal lateral radial physis following application of local anesthetic and surgical preparation of a pre-placed hole. All horses were evaluated weekly after surgery and screw removal was performed standing and under sedation when correction of the angular limb deformity was achieved. The mean time for screw removal was 46 days. No short- or long-term complications were identified. Findings indicate that placing a single transphyseal screw in the lateral aspect of the distal radial physis with the horse standing is a viable option to treat varus angular limb deformity of the carpus in horses. PMID:26028683

  19. Physeal injuries of the distal tibia: long-term results in 376 patients

    PubMed Central

    Binder, Harald; Platzer, Patrick; Schulz, Martin; Hajdu, Stefan; Vécsei, Vilmos

    2009-01-01

    The aim of this study was to evaluate our treatment of distal tibial physeal injuries retrospectively and explain the relationship between the trauma mechanism, the radiographic injury pattern, the subsequent therapy and the functional outcome, as well as to further deduce and verify prognostic criteria. At the Department of Trauma Surgery, Vienna Medical University, 419 children and adolescent patients with physeal injuries of the distal tibia were treated from 1993 to 2007, of these 376 were included in our study and evaluated retrospectively. Seventy-seven displaced physeal fractures of the distal tibia were reconstructed anatomically by open or closed reduction and produced 95% excellent results. A perfect anatomical reduction, if necessary by open means, should be achieved to prevent a bone bridge with subsequent epiphysiodesis and post-traumatic deformities due to growth inhibition and/or retardation. PMID:19662414

  20. Fixation of unstable type II clavicle fractures with distal clavicle plate and suture button.

    PubMed

    Johnston, Peter S; Sears, Benjamin W; Lazarus, Mark R; Frieman, Barbara G

    2014-11-01

    This article reports on a technique to treat unstable type II distal clavicle fractures using fracture-specific plates and coracoclavicular augmentation with a suture button. Six patients with clinically unstable type II distal clavicle fractures underwent treatment using the above technique. All fractures demonstrated radiographic union at 9.6 (8.4-11.6) weeks with a mean follow-up of 15.6 (12.4-22.3) months. American Shoulder and Elbow Surgeons, Penn Shoulder Score, and Single Assessment Numeric Evaluation scores were 97.97 (98.33-100), 96.4 (91-99), and 95 (90-100), respectively. One patient required implant removal. Fracture-specific plating with suture-button augmentation for type II distal clavicle fractures provides reliable rates of union without absolute requirement for implant removal.

  1. Initiation of proximal-distal patterning in the vertebrate limb by signals and growth.

    PubMed

    Cooper, Kimberly L; Hu, Jimmy Kuang-Hsien; ten Berge, Derk; Fernandez-Teran, Marian; Ros, Maria A; Tabin, Clifford J

    2011-05-27

    Two broad classes of models have been proposed to explain the patterning of the proximal-distal axis of the vertebrate limb (from the shoulder to the digit tips). Differentiating between them, we demonstrate that early limb mesenchyme in the chick is initially maintained in a state capable of generating all limb segments through exposure to a combination of proximal and distal signals. As the limb bud grows, the proximal limb is established through continued exposure to flank-derived signal(s), whereas the developmental program determining the medial and distal segments is initiated in domains that grow beyond proximal influence. In addition, the system we have developed, combining in vitro and in vivo culture, opens the door to a new level of analysis of patterning mechanisms in the limb.

  2. Ipsilateral distal femoral and proximal tibial epiphyseal growth plate injury: a case report

    PubMed Central

    2013-01-01

    Introduction Both the isolated distal femoral epiphysiolysis and the isolated proximal tibial epiphysiolysis are the least common epiphyseal injuries. Even though they are uncommon, they have a high incidence rate of complications. Case presentation We present a case with Gustilo-Anderson grade 3b open and Salter-Harris type 1 epiphysiolysis of the distal femur and proximal tibia caused by a farm machinery accident. The patient was a 10-year-old boy, treated by open reduction and internal fixation. Conclusion Although distal femoral and proximal tibial growth plate injuries are rarely seen benign fractures, their management requires meticulous care. Anatomic reduction is important, especially to minimize the risk of growth arrest and the development of degenerative arthritis. However, there is a high incidence of growth arrest and neurovascular injury with these type of fractures. PMID:23724954

  3. Salter-Harris type-IV displaced distal radius fracture in a 5-year-old.

    PubMed

    Huntley, Samuel R; Summers, Spencer H; Stricker, Stephen J

    2016-03-01

    Displaced Salter-Harris type-IV fractures are rare in young children and can result in articular incongruity or premature physeal arrest. We describe a 5-year-old boy who sustained a displaced left distal radial Salter-Harris type-IV fracture. The patient had normal wrist function and physeal growth at the 3-year postoperative follow-up. Our patient is by far the youngest reported child with a displaced Salter-Harris type-IV fracture of the distal radius. Prompt anatomic reduction and fixation of a displaced distal radial Salter-Harris type-IV fracture can result in excellent short-term wrist motion with maintenance of physeal function.

  4. A novel solution to reduce the complications of distal shunt catheter displacement associated with obesity.

    PubMed

    Morrison, John F; Sung, Kristin E; Bergman, Ari M; Rosenblatt, Michael S; Arle, Jeffrey E

    2010-12-01

    Despite the varied sources of hydrocephalus, all shunt-treated conditions involve redirection of CSF to the body, commonly the peritoneum. Migration of the distal catheter tip out of the peritoneal space can occur, leading to the need for reoperation. Although uncommon, the authors have recently had 3 such cases in obese patients involving distal tubing retropulsion in otherwise uncomplicated surgeries. In addressing this issue, the authors performed anchoring of the distal catheter tubing through a small abdominal mesh, which is commonly used for hernia repair to increase catheter tube friction without compromising CSF flow. The results suggest this method may mitigate the chance of peritoneal catheter displacement in patients with higher than normal intraabdominal pressure.

  5. Ligamentum teres hepatis patch enhances the healing of pancreatic fistula after distal pancreatectomy.

    PubMed

    Wu, Chun-Tao; Xu, Wen-Yan; Liu, Liang; Long, Jiang; Xu, Jin; Ni, Quan-Xing; Liu, Chen; Yu, Xian-Jun

    2013-12-01

    Pancreatic fistula is one of the most common complications after the distal pancreatectomy. Many methods have been tried to solve the problem, but no one is optimal, especially for the soft pancreatic stump cases. This study used ligamentum teres hepatis as a patch to cover the pancreatic stump. Between October 2010 and December 2012, seventy-seven patients who had undergone distal pancreatectomy with a soft pancreatic stump were divided into two groups: group A (n=39, patients received conventional ligated main pancreatic duct method) and group B (n=38, patients underwent a coverage procedure). Patients in group A had a longer recovery from postoperative pancreatic fistula than those in group B (16.4+/-3.5 vs 10.8+/-1.6 days, P<0.05). The coverage procedure with ligamentum teres hepatis is a safe, effective and convenient method for patients with a soft pancreas remnant during distal pancreatectomy.

  6. The relationship between displacement and clinical outcome after distal radius (Colles') fracture.

    PubMed

    Finsen, V; Rod, O; Rød, K; Rajabi, B; Alm-Paulsen, P S; Russwurm, H

    2013-02-01

    We reviewed 260 patients who had been treated non-operatively for a dorsally displaced distal radius fracture a mean 6.3 (range 2.5-12.7) years earlier, in an attempt to find the limits of displacement compatible with a good clinical outcome. We excluded patients with previous or later injuries to the same limb. Bivariate analysis revealed a highly statistically significant relationship between radiographic displacement at review and clinical outcome scores. Correlation coefficients varied between 0.14 and 0.30. However, multiple linear regression analysis using most factors commonly thought to be of importance in determining the clinical outcome as independent variables explained only 23% of the variability of the clinical outcome. Dorsal angulation, ulnar variance, and radial inclination together accounted for only 11% of the variability. We conclude that the final alignment of the distal radius as shown radiologically has only a minor influence on the clinical outcome of Colles' type distal radius fractures.

  7. Esophagojejunal Anastomosis Fistula, Distal Esophageal Stenosis, and Metalic Stent Migration after Total Gastrectomy

    PubMed Central

    Al Hajjar, Nadim; Popa, Calin; Al-Momani, Tareg; Margarit, Simona; Graur, Florin; Tantau, Marcel

    2015-01-01

    Esophagojejunal anastomosis fistula is the main complication after a total gastrectomy. To avoid a complex procedure on friable inflamed perianastomotic tissues, a coated self-expandable stent is mounted at the site of the anastomotic leak. A complication of stenting procedure is that it might lead to distal esophageal stenosis. However, another frequently encountered complication of stenting is stent migration, which is treated nonsurgically. When the migrated stent creates life threatening complications, surgical removal is indicated. We present a case of a 67-year-old male patient who was treated at our facility for a gastric adenocarcinoma which developed, postoperatively, an esophagojejunostomy fistula, a distal esophageal stenosis, and a metallic coated self-expandable stent migration. To our knowledge, this is the first reported case of an esophagojejunostomy fistula combined with a distal esophageal stenosis as well as with a metallic coated self-expandable stent migration. PMID:25945277

  8. Esophagojejunal anastomosis fistula, distal esophageal stenosis, and metalic stent migration after total gastrectomy.

    PubMed

    Al Hajjar, Nadim; Popa, Calin; Al-Momani, Tareg; Margarit, Simona; Graur, Florin; Tantau, Marcel

    2015-01-01

    Esophagojejunal anastomosis fistula is the main complication after a total gastrectomy. To avoid a complex procedure on friable inflamed perianastomotic tissues, a coated self-expandable stent is mounted at the site of the anastomotic leak. A complication of stenting procedure is that it might lead to distal esophageal stenosis. However, another frequently encountered complication of stenting is stent migration, which is treated nonsurgically. When the migrated stent creates life threatening complications, surgical removal is indicated. We present a case of a 67-year-old male patient who was treated at our facility for a gastric adenocarcinoma which developed, postoperatively, an esophagojejunostomy fistula, a distal esophageal stenosis, and a metallic coated self-expandable stent migration. To our knowledge, this is the first reported case of an esophagojejunostomy fistula combined with a distal esophageal stenosis as well as with a metallic coated self-expandable stent migration.

  9. Development of sympathetic innervation to proximal and distal arteries of the rat mesentery.

    PubMed Central

    Hill, C E; Hirst, G D; van Helden, D F

    1983-01-01

    The changes which occur during the post-natal development of sympathetic innervation to proximal and distal arteries of the rat mesentery have been examined using intracellular recording and histochemical techniques. In the youngest animals examined, single perivascular stimuli initiated slow depolarizing potentials which were not calcium-dependent. After day 4, single stimuli failed to initiate membrane potential changes in a proportion of preparations. This stage coincided with the period of extensive ramification of sympathetic nerve fibres over the surface of the arterioles. From day 9 onwards, membrane potential changes were again initiated by single stimuli in the distal arteries. These responses were distinct from those recorded from the younger animals and in many ways resembled excitatory junction potentials recorded from the arteries of mature animals. There was a gradient in the development of the innervation to the arteries of the rat mesentery, with that to the distal vessels maturing earlier than that to the more proximal vessels. PMID:6875954

  10. Ventriculoperitoneal Shunting Surgery with Open Distal Shunt Catheter Placement in the Treatment of Hydrocephalus.

    PubMed

    Zhang, Yang; Zhu, Xiaobo; Zhao, Jinchuan; Hou, Kun; Gao, Xianfeng; Sun, Yang; Wang, Wei; Zhang, Xiaona

    2015-11-01

    Ventriculoperitoneal shunting (VPS) is a major therapy for hydrocephalus, but has a significant risk of device malfunctioning. In this study, we explored a novel distal shunt catheter placement method in VPS for the treatment of hydrocephalus. Five patients with different etiologies of hydrocephalus underwent VPS with open distant shunt catheter attached outside. We analyzed different variables (age, gender, medical history, clinical presentation, indication for surgery and surgical technique, postoperative complications) and occurrence of shunt failure and infection. All hydrocephalus patients who received the distal shunt catheter placed outside can undergo regular VPS again after the condition improves. The modified VPS in the treatment of hydrocephalus with the distal shunt catheter placed outside could potentially reduce the necessity of repeat surgery for addressing the complications caused by catheter obstruction and infections, reduce the chance of adhesions, and would be of benefit to those patients who need future revisions.

  11. Reconstruction of the Distal Radius following Tumour Resection Using an Osteoarticular Allograft

    PubMed Central

    Maurer-Ertl, Werner; Pirker-Frühauf, Ulrike; Lovse, Thomas; Leithner, Andreas

    2013-01-01

    Reconstruction of the distal radius following tumour resection is challenging and various techniques are recorded. We retrospectively analysed the outcome of five patients (one male and four females) after reconstruction of the distal radius with osteoarticular allograft, following tumour resection. Mean followup was 32 months (range, 4–121). In three of the five patients the dominant limb was affected. Mean bone resection length was 6.5 centimetres (range, 5–11.5). Two grafts developed nonunion, both successfully treated with autologous bone grafting. No infection, graft fracture, or failure occurred. Mean flexion/extension was 38/60 degrees and mean pronation/supination was 77/77 degrees. The mean Mayo wrist score was 84 and the mean DASH score was 8, both representing a good functional result. Therefore we state the notion that osteoarticular allograft reconstruction of distal radius provides good to excellent functional results. PMID:23690732

  12. Spontaneous rupture of the distal iliopsoas tendon: clinical and imaging findings, with anatomic correlations.

    PubMed

    Lecouvet, Frederic E; Demondion, Xavier; Leemrijse, Thibaut; Vande Berg, Bruno C; Devogelaer, Jean-Pierre; Malghem, Jacques

    2005-11-01

    We report the clinical and imaging findings in two elderly female patients with spontaneous rupture of the distal iliopsoas tendon from the lesser trochanter of the femur. We emphasize the key contribution of magnetic resonance (MR) imaging to this diagnosis and provide an anatomic correlation. Spontaneous rupture of the distal iliopsoas tendon should be kept in mind in the differential diagnosis of acute groin pain in the elderly. MR imaging enables positive diagnosis, by showing mass effect on the anterior aspect of the hip joint, proximal muscle thickening, and abnormal signal intensity, and by demonstrating interruption of the psoas tendon, whereas the distal insertion of the lateral portion of the iliacus muscle remains muscular and is preserved.

  13. Amyloidogenicity at a Distance: How Distal Protein Regions Modulate Aggregation in Disease.

    PubMed

    Lucato, Christina M; Lupton, Christopher J; Halls, Michelle L; Ellisdon, Andrew M

    2017-03-22

    The misfolding of proteins to form amyloid is a key pathological feature of several progressive, and currently incurable, diseases. A mechanistic understanding of the pathway from soluble, native protein to insoluble amyloid is crucial for therapeutic design, and recent efforts have helped to elucidate the key molecular events that trigger protein misfolding. Generally, either global or local structural perturbations occur early in amyloidogenesis to expose aggregation-prone regions of the protein that can then self-associate to form toxic oligomers. Surprisingly, these initiating structural changes are often caused or influenced by protein regions distal to the classically amyloidogenic sequences. Understanding the importance of these distal regions in the pathogenic process has highlighted many remaining knowledge gaps regarding the precise molecular events that occur in classic aggregation pathways. In this review, we discuss how these distal regions can influence aggregation in disease and the recent technical and conceptual advances that have allowed this insight.

  14. A new mode for heme-heme interactions in hemoglobin associated with distal perturbations.

    PubMed Central

    Levy, A; Sharma, V S; Zhang, L; Rifkind, J M

    1992-01-01

    The distal side of the heme pocket, known to regulate ligand affinity, is shown to be directly involved in subunit interactions. Valency hybrids with oxygen or carbon monoxide bound to the reduced chain are used to model R-state hemoglobin with different distal perturbations. Electron paramagnetic resonance of the oxidized chains shows that the carbon monoxide perturbation is transmitted between subunits to the distal histidine and the oxidized iron center. A comparison of hybrids with only one type of chain oxidized and hybrids with a single alpha beta dimer oxidized is consistent with this perturbation being transmitted across the alpha 1 beta 1 interface. This represents a new mode of subunit interactions in hemoglobin. Images FIGURE 3 FIGURE 4 PMID:1324020

  15. Pathology of the distal phalanx in equine laminitis: more than just skin deep.

    PubMed

    Engiles, Julie B

    2010-04-01

    The etiopathogenesis of laminitis is complex and involves multiple tissue types. It may be initiated by biomechanical, traumatic, inflammatory, vascular, toxic, and metabolic factors. Although histopathologic changes occurring within the lamellae of experimental models of laminitis are well described and reported, histopathologic changes occurring in the distal phalanx are not, even though gross and radiographic evidence of disease are often apparent and bony lesions could be considered a significant source of pain. Recent scientific evidence indicates that the microenvironment of bone is an important modulator of inflammatory processes that can both influence, and be influenced by components of other organ systems, including the immune, nervous, gastrointestinal, and integumentary systems. This article describes various laminitis-associated histopathological changes in the distal phalanx, introduces concepts of osteoimmunology with regards to equine laminitis, and provides a rationale for histopathological examination of the distal phalanx, as well as the soft tissue structures of the lamellae and corium in laminitis cases.

  16. Treatment of distal radius fractures with intrafocal (kapandji) pinning and supplemental skeletal stabilization.

    PubMed

    Weil, Wayne M; Trumble, Thomas E

    2005-08-01

    The technique of intrafocal pinning was originally described by Kapandji. This technique, along with the addition of supplemental external or internal bridging fixation, can be performed quickly with minimal soft tissue damage. This technique is indicated for the treatment of unstable extra-articular or minimally displaced intra-articular fractures of the distal radius. Studies demonstrate that young patients with displaced extra-articular distal radius fractures and minimal comminution can be treated by percutaneous intrafocal pin fixation alone, whereas, patients over 55 years of age and younger patients with comminution involving two or more surfaces of the radial metaphysis (or > 50% of the metaphyseal diameter) require bridging fixation besides percutaneous pin fixation. The use of this technique achieves the goal of surgical treatment of distal radius fractures: restoration of hand and wrist function through the restoration of alignment and articular surface congruity.

  17. Distal femoral physeal growth arrest secondary to a cemented proximal femoral endoprosthetic replacement.

    PubMed

    Gaston, C L; Tillman, R M; Grimer, R J

    2011-05-01

    We report a case of spontaneous physeal growth arrest of the distal femur in a nine-year-old child with Ewing's sarcoma of the proximal femur treated with chemotherapy and endoprosthetic replacement. Owing to the extent of disuse osteoporosis at the time of surgery, the entire intramedullary canal up to the distal femoral physis was filled with cement. Three years later, the femur remained at its pre-operative length of 19 cm. Pre-operative calculations of further growth failed to account for the growth arrest, and the initial expandable growing prosthesis inserted has been revised to a longer one in order to address the leg-length discrepancy. To our knowledge, this is the only reported case of distal femoral physeal growth arrest following cemented endoprosthetic replacement of the proximal femur.

  18. Percutaneous cementoplasty for painful osteolytic distal femur metastases: a case report.

    PubMed

    Lei, Mingxing; Liu, Yaosheng; Yang, Shaoxing; Jiang, Weigang; Cao, Yuncen; Liu, Shubin

    2016-01-01

    Percutaneous cementoplasty has been shown to immediately restore the mechanical stability of affected bones, prevent further risk of bone fractures, and allow immediate weight bearing. It is emerging as one of the most promising procedures for patients with painful bone metastasis who are unsuitable for surgery or who show resistance to radiotherapy and/or analgesic therapies. This study aimed at describing the procedure, indications, and benefits of percutaneous cementoplasty for painful osteolytic distal femur metastases. We report the case of a painful metastatic lesion in the left distal femur secondary to non-small-cell lung cancer in a 58-year-old woman. The patient underwent percutaneous cementoplasty and experienced effective pain relief and recovery of knee function postoperatively. In addition, no perioperative complication was observed. Percutaneous cementoplasty for osteolytic distal femur metastases offers effective pain relief and restores impaired knee function. Although this method may be a safe option, larger samples of retrospective or prospective confirmation are warranted.

  19. Percutaneous cementoplasty for painful osteolytic distal femur metastases: a case report

    PubMed Central

    Lei, Mingxing; Liu, Yaosheng; Yang, Shaoxing; Jiang, Weigang; Cao, Yuncen; Liu, Shubin

    2016-01-01

    Percutaneous cementoplasty has been shown to immediately restore the mechanical stability of affected bones, prevent further risk of bone fractures, and allow immediate weight bearing. It is emerging as one of the most promising procedures for patients with painful bone metastasis who are unsuitable for surgery or who show resistance to radiotherapy and/or analgesic therapies. This study aimed at describing the procedure, indications, and benefits of percutaneous cementoplasty for painful osteolytic distal femur metastases. We report the case of a painful metastatic lesion in the left distal femur secondary to non-small-cell lung cancer in a 58-year-old woman. The patient underwent percutaneous cementoplasty and experienced effective pain relief and recovery of knee function postoperatively. In addition, no perioperative complication was observed. Percutaneous cementoplasty for osteolytic distal femur metastases offers effective pain relief and restores impaired knee function. Although this method may be a safe option, larger samples of retrospective or prospective confirmation are warranted. PMID:27799817

  20. Secondary omental infarction related to open and laparoscopic-assisted distal gastrectomy: report of two cases.

    PubMed

    Park, Kyung Eun; Chung, Dong Jin; Kim, Wook; Hahn, Seong-Tae; Lee, Jae Moon

    2011-01-01

    Omental infarction occurring after open and laparoscopic-assisted distal gastrectomy with partial omentectomy for gastric cancer was a very rare disease in the past, but its incidence has increased as more partial omentectomies are now being performed. But there are few case reports or radiologic studies on its increasing incidence. It is necessary to differentiate omental infarction from carcinomatosis peritonei, since both have similar imaging findings. In this report, we describe two cases of omental infarction; each occurred after open and laparoscopic-assisted distal gastrectomy in early gastric cancer patients. Partial omentectomy was performed in both cases. Omental infarction following distal gastrectomy with partial omentectomy can be discriminated from carcinomatosis peritonei by comparing with different initial and follow up CT findings.