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1

A case of nodular regenerative hyperplasia of the liver combined with toxic hepatitis.  

PubMed

Nodular regenerative hyperplasia (NRH) is an uncommon liver condition characterized by diffuse transformation of the hepatic parenchyma into regenerative nodules without fibrosis. Portal vasculopathy caused by abnormal hepatic venous flow may induce hepatocyte hyperplasia, which forms regenerative nodules. Underlying diseases or certain drugs may also be the cause of NRH. This condition is often underdiagnosed as the patients remain asymptomatic until development of portal hypertension, and histopathologic confirmation by liver biopsy is the only way of making a definite diagnosis. The management mainly involves prevention and treatment of the complications of portal hypertension. The frequency of diagnosis of NRH has increased rapidly in recent years, however, only a few cases have been reported in Korea. Here, we report on a case of NRH of the liver combined with toxic hepatitis. (Korean J Gastroenterol 2015;65:52-56). PMID:25603855

Jin, Sun Mi; Song, Sang Hee; Cho, Yang Hyun; Shin, Dae Kyu; Shin, Sun Young; Kim, Gwang Il; Park, Hana; Rim, Kyu Sung

2015-01-25

2

Nodular regenerative hyperplasia: Evolving concepts on underdiagnosed cause of portal hypertension  

PubMed Central

Nodular regenerative hyperplasia (NRH) is a rare liver condition characterized by a widespread benign transformation of the hepatic parenchyma into small regenerative nodules. NRH may lead to the development of non-cirrhotic portal hypertension. There are no published systematic population studies on NRH and our current knowledge is limited to case reports and case series. NRH may develop via autoimmune, hematological, infectious, neoplastic, or drug-related causes. The disease is usually asymptomatic, slowly or non-progressive unless complications of portal hypertension develop. Accurate diagnosis is made by histopathology, which demonstrates diffuse micronodular transformation without fibrous septa. Lack of perinuclear collagen tissue distinguishes NRH from typical regenerative nodules in the cirrhotic liver. While the initial treatment is to address the underlying disease, ultimately the therapy is directed to the management of portal hypertension. The prognosis of NRH depends on both the severity of the underlying illness and the prevention of secondary complications of portal hypertension. In this review we detail the epidemiology, pathogenesis, diagnosis, management, and prognosis of NRH. PMID:21472097

Hartleb, Marek; Gutkowski, Krzysztof; Milkiewicz, Piotr

2011-01-01

3

Nodular regenerative hyperplasia mimicking cirrhosis of the liver.  

PubMed Central

Nodular regenerative hyperplasia of the liver usually presents with signs of portal hypertension with little evidence of obvious liver disease. We report a 47 year old man who presented with clinical signs of decompensated cirrhosis, recurrent encephalopathy, and tense ascites but at liver transplant was found to have nodular regenerative hyperplasia associated with a portal vein thrombosis. Images Figure 1 Figure 2 Figure 3 PMID:2379880

McDonald, J A; Painter, D M; Gallagher, N D; McCaughan, G W

1990-01-01

4

Hepatoportal sclerosis (obliterative portal venopathy) and nodular regenerative hyperplasia in a patient with myasthenia gravis: A case report and review of the published work.  

PubMed

Nodular regenerative hyperplasia (NRH) and hepatoportal sclerosis, also known as obliterative portal venopathy (OPV), are two causes of non-cirrhotic portal hypertension (NCPH). NCPH is an increasingly recognized entity that can be seen in association with collagen vascular diseases and with the use of medications such as azathioprine and didanosine, but oftentimes the etiology remains unidentified. We herein report a case of NCPH occurring due to OPV and NRH in a 64-year-old woman with myasthenia gravis (MG), status post-thymectomy. Portal hypertension was diagnosed incidentally on computed tomography in the absence of predisposing factors. Extensive work-up to determine the etiology of any underlying liver disease was unrevealing. NRH and OPV were identified on liver biopsy. Subsequently, the patient had variceal bleeding that necessitated transjugular intrahepatic portosystemic shunt placement. A few similar cases of NCPH occurring in the setting of MG have been previously reported, suggesting that the immunological mechanisms involved in the pathogenesis of myasthenia may also have contributed to the development of NCPH. PMID:23675894

Agrawal, Manasi; Rahmani, Rabin; Nakkala, Kiran; Fiel, Maria Isabel; Schiano, Thomas

2013-09-01

5

Hepatopulmonary syndrome associated with nodular regenerative hyperplasia after liver transplantation in a child.  

PubMed

HPS is a significant complication of portal hypertension in children with chronic liver disease and is an established indication for LT. It is characterized clinically by the triad of pulmonary vascular dilatation causing hypoxemia in the setting of advanced liver disease. NRH, a cause of non-cirrhotic portal hypertension, is characterized by diffuse benign transformation of the hepatic parenchyma into small regenerative nodules with minimal or no fibrosis. Development of NRH and HPS in pediatric LT recipients has not been reported, although occasional cases have been reported in adult LT recipients. In this report, we discuss a case of a three-yr-old male who developed HPS, two yr after LT. Pulmonary and cardiac causes for hypoxemia were ruled out by appropriate investigations including a chest X ray, echocardiogram, cardiac catheterization, and a CT angiographic study. The diagnosis of HPS was confirmed via bubble echocardiogram that demonstrated intrapulmonary shunting. Open liver biopsy revealed marked NRH. The patient underwent liver retransplantation that resulted in complete reversal of his pulmonary symptoms and normal oxygen saturations within three months after LT. PMID:24820314

Alhosh, Rabea; Genyk, Yuri; Alexopoulos, Sophoclis; Thomas, Daniel; Zhou, Shengmei; Yanni, George; Kerkar, Nanda

2014-08-01

6

Concurrent Liver Hodgkin Lymphoma and Nodular Regenerative Hyperplasia on an Explanted Liver with Clinical Diagnosis of Alcoholic Cirrhosis at University Hospital Fundación Santa Fe de Bogotá  

PubMed Central

Liver involvement by Hodgkin lymphoma (HL) is well documented. However, secondary liver failure to this neoplastic process is rare and usually presents late in the course of the disease. We present a case of a HL associated with nodular regenerative hyperplasia (NRH) diagnosed on an explanted liver from a 53-year-old patient with clinical diagnosis of alcoholic cirrhosis. Hematoxylin and eosin stain (H&E) showed abnormal liver architecture with hepatocytes nodules highlighted by reticulin stain with absent fibrosis on the trichrome stain. The portal spaces had diffuse infiltration by Reed-Sternberg cells positive for CD15, CD30, and latent membrane protein (LMP) on immunohistochemical studies. The patient also had a concurrent hilar lymph node biopsy that also showed HL involvement. Liver failure as the initial presentation of Hodgkin' lymphoma is rare. We believe that more research about the utility of performing liver biopsies in patients candidates for transplantation with noncirrhotic hepatic failure is needed in order to establish the etiology and the optimal treatment. PMID:24511402

López, R.; Barrera, L.; Vera, A.; Andrade, R.

2014-01-01

7

Pregnancy restores the regenerative capacity of the aged liver via activation of an mTORC1-controlled hyperplasia/hypertrophy switch  

PubMed Central

Regenerative capacity is progressively lost with age. Here we show that pregnancy markedly improved liver regeneration in aged mice concomitantly with inducing a switch from proliferation-based liver regeneration to a regenerative process mediated by cell growth. We found that the key mediator of this switch was the Akt/mTORC1 pathway; its inhibition blocked hypertrophy, while increasing proliferation. Moreover, pharmacological activation of this pathway sufficed to induce the hypertrophy module, mimicking pregnancy. This treatment dramatically improved hepatic regenerative capacity and survival of old mice. Thus, cell growth-mediated mass reconstitution, which is relatively resistant to the detrimental effects of aging, is employed in a physiological situation and holds potential as a therapeutic strategy for ameliorating age-related functional deterioration. PMID:20231314

Gielchinsky, Yuval; Laufer, Neri; Weitman, Efi; Abramovitch, Rinat; Granot, Zvi; Bergman, Yehudit; Pikarsky, Eli

2010-01-01

8

Severe systemic toxicity and urinary bladder cytotoxicity and regenerative hyperplasia induced by arsenite in arsenic (+ 3 oxidation state) methyltransferase knockout mice. A preliminary report  

SciTech Connect

Arsenic (+ 3 oxidation state) methyltransferase (As3mt) catalyzes reactions which convert inorganic arsenic to methylated metabolites. This study determined whether the As3mt null genotype in the mouse modifies cytotoxic and proliferative effects seen in urinary bladders of wild type mice after exposure to inorganic arsenic. Female wild type C57BL/6 mice and As3mt KO mice were divided into 3 groups each (n = 8) with free access to a diet containing 0, 100 or 150 ppm of arsenic as arsenite (As{sup III}). During the first week of As{sup III} exposure, As3mt KO mice exhibited severe and lethal systemic toxicity. At termination, urinary bladders of both As3mt KO and wild type mice showed hyperplasia by light microscopy. As expected, arsenic-containing granules were found in the superficial urothelial layer of wild type mice. In As3mt KO mice these granules were present in all layers of the bladder epithelium and were more abundant and larger than in wild type mice. Scanning electron microscopy of the bladder urothelium of As3mt KO mice treated with 100 ppm As{sup III} showed extensive superficial necrosis and hyperplastic changes. In As3mt KO mice, livers showed severe acute inflammatory changes and spleen size and lymphoid areas were decreased compared with wild type mice. Thus, diminished arsenic methylation in As3mt KO mice exacerbates systemic toxicity and the effects of As{sup III} on the bladder epithelium, showing that altered kinetic and dynamic behavior of arsenic can affect its toxicity.

Yokohira, Masanao; Arnold, Lora L.; Pennington, Karen L. [Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198-3135 (United States); Suzuki, Shugo [Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198-3135 (United States); Department of Experimental Pathology and Tumor Biology, Nagoya City University Graduate School of Medical Sciences (Japan); Kakiuchi-Kiyota, Satoko [Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198-3135 (United States); Herbin-Davis, Karen; Thomas, David J. [Pharmacokinetics Branch, Integrated Systems Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Cohen, Samuel M., E-mail: scohen@unmc.ed [Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198-3135 (United States)

2010-07-15

9

Endometrial Hyperplasia  

MedlinePLUS

... is endometrial hyperplasia? Endometrial hyperplasia occurs when the endometrium , the lining of the uterus , becomes too thick. ... to cancer of the uterus. How does the endometrium normally change throughout the menstrual cycle? The endometrium ...

10

The two common polymorphic forms of human NRH-quinone oxidoreductase 2 (NQO2) have different biochemical properties  

PubMed Central

There are two common forms of NRH-quinone oxidoreductase 2 (NQO2) in the human population resulting from SNP rs1143684. One has phenylalanine at position 47 (NQO2-F47) and the other leucine (NQO2-L47). Using recombinant proteins, we show that these variants have similar steady state kinetic parameters, although NQO2-L47 has a slightly lower specificity constant. NQO2-L47 is less stable towards proteolytic digestion and thermal denaturation than NQO2-F47. Both forms are inhibited by resveratrol, but NQO2-F47 shows negative cooperativity with this inhibitor. Thus these data demonstrate, for the first time, clear biochemical differences between the variants which help explain previous biomedical and epidemiological findings. PMID:24631540

Megarity, Clare F.; Gill, James R.E.; Clare Caraher, M.; Stratford, Ian J.; Nolan, Karen A.; Timson, David J.

2014-01-01

11

Regenerative Aerobraking  

NASA Technical Reports Server (NTRS)

NASA's exploration goals for Mars and Beyond will require new power systems and in situ resource utilization technologies. Regenerative aerobraking may offer a revolutionary approach for in situ power generation and oxygen harvesting during these exploration missions. In theory, power and oxygen can be collected during aerobraking and stored for later use in orbit or on the planet. This technology would capture energy and oxygen from the plasma field that occurs naturally during hypersonic entry using well understood principles of magnetohydrodynamics and oxygen filtration. This innovative approach generates resources upon arrival at the operational site, and thus greatly differs from the traditional approach of taking everything you need with you from Earth. Fundamental analysis, computational fluid dynamics, and some testing of experimental hardware have established the basic feasibility of generating power during a Mars entry. Oxygen filtration at conditions consistent with spacecraft entry parameters at Mars has been studied to a lesser extent. Other uses of the MHD power are presented. This paper illustrates how some features of regenerative aerobraking may be applied to support human and robotic missions at Mars.

Moses, Robert W.

2004-01-01

12

Adrenal medullary hyperplasia. Hyperplasia-pheochromocytoma sequence.  

PubMed

We present a case of unilateral adrenal medullary hyperplasia in a 63-year-old woman with clinical signs and symptoms of pheochromocytoma unassociated with multiple endocrine neoplasia. The surgically removed adrenal gland revealed diffuse medullary hyperplasia with multiple micronodules measuring up to 2 mm. The micronodules were composed of enlarged chromaffin cells with atypia, histologically similar to those of pheochromocytoma, forming small solid alveolar patterns separated by a fibrovascular stroma. Removal of the hyperplastic adrenal gland resulted in disappearance of paroxysmal nocturnal hypertension and palpitation. These results suggest that diffuse and nodular medullary hyperplasia is the precursor of pheochromocytoma. PMID:2260475

Kurihara, K; Mizuseki, K; Kondo, T; Ohoka, H; Mannami, M; Kawai, K

1990-09-01

13

Reversible papillary hyperplasia of the rat urinary bladder.  

PubMed

A rapid reproducible method for the production of ulcers and reversible regenerative hyperplasia of the urinary bladder of rats is described. This method does not involve administration of a toxic chemical or retention of a foreign body. Ulceration was produced by means of applying a steel rod, 5 mm in diameter, frozen at -78 C, to the serosal surface of the bladder for 2 seconds, twice, with a 5-second interval between each application. Sequential histologic observations showed that ulcers were accompanied by necrosis of the entire thickness of the bladder at the site of freezing with extensive acute inflammation. Regenerative hyperplasia was evident at the edge of the ulcer by the second day, with greatest severity at 5 days when papillary and nodular hyperplasia were present. At 15 days the bladders were normal or had only minimal hyperplasia. The labeling index by autoradiography was highest in the mildly hyperplastic area near the ulcer at 2 days and remained relatively high through 5 days. The hyperplastic epithelium surrounding the ulcer observed by scanning electron microscopy had numerous degenerative cells on the surface, and small epithelial cells with numerous short, uniform microvilli on their luminal surface were also observed. The numerous short, uniform microvilli on their luminal surface were also observed. The microvilli had a symmetric luminal membrane, as observed on trasmission electron microscopy. More peripherally the cells had microridges only or microvilli and microridges on their luminal surface. Neither pleomorphic microvili nor a structured glycocalyx fuzz on microvilli was observed during the process of regenerative hyperplasia, distinguishing it from neoplastic bladder proliferations. PMID:645820

Shirai, T; Cohen, S M; Fukushima, S; Hananouchi, M; Ito, N

1978-04-01

14

Regenerative (Regen) ECLSS Operations Water Balance  

NASA Technical Reports Server (NTRS)

In November 2008, the Water Regenerative System racks were launched aboard Space Shuttle flight, STS-126 (ULF2) and installed and activated on the International Space Station (ISS). These racks, consisting of the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA), completed the installation of the Regenerative (Regen) ECLSS systems which includes the Oxygen Generator Assembly (OGA) that was launched 2 years prior. With the onset of active water management on the US segment of the ISS, a new operational concept was required, that of "water balance." Even more recently, in 2010 the Sabatier system came online which converts H2 and CO2 into water and methane. The Regen ECLSS systems accept condensation from the atmosphere, urine from crew, and processes that fluid via various means into potable water which is used for crew drinking, building up skip-cycle water inventory, and water for electrolysis to produce oxygen. Specification rates of crew urine output, condensate output, O2 requirements, toilet flush water and drinking needs are well documented and used as a general plan when Regen ECLSS came online. Spec rates are useful in long term planning, however, daily or weekly rates are dependent on a number of variables. The constantly changing rates created a new challenge for the ECLSS flight controllers, who are responsible for operating the ECLSS systems onboard ISS. This paper will review the various inputs to rate changes and inputs to planning events, including but not limited to; crew personnel makeup, Regen ECLSS system operability, vehicle traffic, water containment availability, and Carbon Dioxide Removal Assembly (CDRA) capability. Along with the inputs that change the various rates, the paper will review the different systems, their constraints and finally the operational means by which flight controllers manage this new challenge of "water balance."

Tobias, Barry

2010-01-01

15

Indolequinone Inhibitors of NRH:Quinone Oxidoreductase 2 (NQO2). Characterization of Mechanism of Inhibition in both Cell-free and Cellular Systems. †  

PubMed Central

We describe a series of indolequinones as efficient mechanism-based inhibitors of NRH:quinone oxidoreductase 2 (NQO2) for use either in cellular or cell-free systems. Compounds were designed to be reduced in the active site of the enzyme leading to loss of a substituted phenol leaving group and generation of a reactive iminium electrophile. Inhibition of NQO2 activity was assessed in both cell-free systems and in the human leukemia K562 cell line. Inhibition of recombinant human NQO2 by the indolequinones was NRH-dependent with kinetic parameters characteristic of mechanism-based inhibition and partition ratios as low as 2.0. Indolequinones inhibited NQO2 activity in K562 cells at nanomolar concentrations which did not inhibit NQO1 and were non-toxic to cells. Computational-based molecular modeling simulations demonstrated favorable conformations of indolequinones positioned directly above and in parallel to the isoalloxazine ring of FAD and mass spectrometry extended our previous finding of adduction of the FAD in the active site of NQO2 by an indolequinone-derived iminium electrophile to the wider series of indolequinone inhibitors. Modeling combined with biochemical testing identified key structural parameters for effective inhibition including a 5-aminoalkyamino side chain. Hydrogen bonding of the terminal amine nitrogen in the aminoalkylamino side chain was found to be critical for correct orientation of the inhibitors in the active site. These indolequinones were irreversible inhibitors and were found to be at least an order of magnitude more potent than any previously documented competitive inhibitors of NQO2 and represent the first mechanism-based inhibitors of NQO2 to be characterized in cellular systems. PMID:21718050

Yan, Chao; Dufour, Marine; Siegel, David; Reigan, Philip; Gomez, Joe; Shieh, Biehuoy; Moody, Christopher J.; Ross, David

2011-01-01

16

Regenerative Life Support Evaluation  

NASA Technical Reports Server (NTRS)

This paper describes the development plan and design concept of the Regenerative Life Support Evaluation (RLSE) planned for flight testing in the European Space Agency Spacelab. The development plan encompasses the ongoing advanced life support subsystem and a systems integration effort to evolve concurrently subsystem concepts that perform their function and can be integrated with other subsystems in a flight demonstration of a regenerative life support system. The design concept for RLSE comprises water-electrolysis O2 generation, electrochemically depolarized CO2 removal, and Sabatier CO2 reduction for atmosphere regeneration, urine vapor-compression distillation, and wash-water hyperfiltration for waste-water recovery. The flight demonstration by RLSE is an important step in qualifying the regenerative concepts for life support in space stations.

Kleiner, G. N.; Thompson, C. D.

1977-01-01

17

Congenital adrenal hyperplasia  

MedlinePLUS

... or inappropriately). Congenital adrenal hyperplasia can affect both boys and girls. About 1 in 10,000 to 18,000 ... penis but normal testes Well-developed muscles Both boys and girls will be tall as children but much shorter ...

18

Nanocomposites for Regenerative Medicine  

Microsoft Academic Search

\\u000a This chapter describes properties and applications of nanocomposites in tissue engineering and regenerative medicine with\\u000a an emphasis on the impact of the nanophase on nanocomposite function. The nanophase can be used as a means to engineer new\\u000a physical properties that improve the utility of tissue engineering scaffolds. Several examples of the use of the nanophase\\u000a for mechanical reinforcement or drug

Ryan Hoshi; Antonio R. Webb; Hongjin Qiu; Guillermo A. Ameer

19

Regenerative feedback resonant circuit  

DOEpatents

A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.

Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.

2014-09-02

20

Regenerative fuel cells  

NASA Technical Reports Server (NTRS)

A development status evaluation is presented for moderate-temperature, single-unit, regenerative fuel cells using either alkaline or solid polymer proton-exchange membrane (PEM) electrolytes. Attention is given to the results thus far obtained for Pt, Ir, Rh, and Na(x)Pt3O4 catalysts. Alkaline electrolyte tests have been performed on a half-cell basis with a floating-electrode cell; PEM testing has been with complete fuel cells, using Nafion 117.

Swette, Larry L.; Kackley, Nancy D.; Laconti, Anthony B.

1992-01-01

21

Cytomics in regenerative medicine  

NASA Astrophysics Data System (ADS)

Cytomics is the high-content analysis of cell-systems [6, 78]. The area of Cytomics and Systems Biology received great attention during the last years as it harbours the promise to substantially impact on various fields of biomedicine, drug discovery, predictive medicine [6] and may have major potential for regenerative medicine. In regenerative medicine Cytomics includes process control of cell preparation and culturing using non-invasive detection techniques, quality control and standardization for GMP and GLP conformity and even prediction of cell fate based on sophisticated data analysis. Cytomics requires quantitative and stoichiometric single cell analysis. In some areas the leading cytometric techniques represent the cutting edge today. Many different applications/variations of multicolour staining were developed for flow- or slide-based cytometry (SBC) analysis of suspensions and sections to whole animal analysis [78]. SBC has become an important analytical technology in drug discovery, diagnosis and research and is an emerging technology for systems analysis [78]. It enables high-content high-throughput measurement of cell suspensions, cell cultures and tissues. In the last years various commercial SBC instruments were launched principally enabling to perform similar tasks. Standardisation as well as comparability of different instruments is a major challenge. Hyperspectral optical imaging may be implemented in SBC analysis for label free cell detection based on cellular autofluorescence [3]. All of these developments push the systemic approach of the analysis of biological specimens to enhance the outcome of regenerative medicine.

Tárnok, Attila; Pierzchalski, Arkadiusz

2008-02-01

22

Hypertrichosis with hereditary gingival hyperplasia  

PubMed Central

Two cases of infantile hypertrichosis who subsequently developed oral abnormalities are described. In one case generalized gingival hyperplasia was associated with retarded eruption of deciduous and permanent teeth and macrodontia. In the second case the mucosal hyperplasia was limited to the palatal surface. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5FIG. 6FIG. 7 PMID:4834021

Winter, G. B.; Simpkiss, M. J.

1974-01-01

23

Polymeric Scaffolds for Regenerative Medicine  

Microsoft Academic Search

Regenerative medicine, one of the most exciting and dynamic life science fields, is an emerging biomedical technology for assisting and accelerating the regeneration and repair of lost or damaged organs or body parts. Modern regenerative medicine is increasingly using three-dimensional structured scaffolds because they represent a wide range of morphological and geometric in vivo possibilities that can be tailored for

Moon Suk Kim; Jae Ho Kim; Byoung Hyun Min; Heung Jae Chun; Dong Keun Han; Hai Bang Lee

2011-01-01

24

Will regenerative medicine replace transplantation?  

PubMed

Recent groundbreaking advances in organ bioengineering and regeneration have provided evidence that regenerative medicine holds promise to dramatically improve the approach to organ transplantation. The two fields, however, share a common heritage. Alexis Carrel can be considered the father of both regenerative medicine and organ transplantation, and it is now clear that his legacy is equally applicable for the present and future generations of transplant and regenerative medicine investigators. In this review, we will briefly illustrate the interplay that should be established between these two complementary disciplines of health sciences. Although regenerative medicine has shown to the transplant field its potential, transplantation is destined to align with regenerative medicine and foster further progress probably more than either discipline alone. Organ bioengineering and regeneration technologies hold the promise to meet at the same time the two most urgent needs in organ transplantation, namely, the identification of a new, potentially inexhaustible source of organs and immunosuppression-free transplantation of tissues and organs. PMID:23906883

Orlando, Giuseppe; Soker, Shay; Stratta, Robert J; Atala, Anthony

2013-08-01

25

Regenerative braking device  

DOEpatents

Disclosed are several embodiments of a regenerative braking device for an automotive vehicle. The device includes a plurality of rubber rollers (24, 26) mounted for rotation between an input shaft (14) connectable to the vehicle drivetrain and an output shaft (16) which is drivingly connected to the input shaft by a variable ratio transmission (20). When the transmission ratio is such that the input shaft rotates faster than the output shaft, the rubber rollers are torsionally stressed to accumulate energy, thereby slowing the vehicle. When the transmission ratio is such that the output shaft rotates faster than the input shaft, the rubber rollers are torsionally relaxed to deliver accumulated energy, thereby accelerating or driving the vehicle.

Hoppie, Lyle O. (Birmingham, MI)

1982-01-12

26

PEM regenerative fuel cells  

NASA Technical Reports Server (NTRS)

This paper will update the progress in developing electrocatalyst systems and electrode structures primarily for the positive electrode of single-unit solid polymer proton exchange membrane (PEM) regenerative fuel cells. The work was done with DuPont Nafion 117 in complete fuel cells (40 sq cm electrodes). The cells were operated alternately in fuel cell mode and electrolysis mode at 80 C. In fuel cell mode, humidified hydrogen and oxygen were supplied at 207 kPa (30 psi); in electrolysis mode, water was pumped over the positive electrode and the gases were evolved at ambient pressure. Cycling data will be presented for Pt-Ir catalysts and limited bifunctional data will be presented for Pt, Ir, Ru, Rh, and Na(x)Pt3O4 catalysts as well as for electrode structure variations.

Swette, Larry L.; Laconti, Anthony B.; Mccatty, Stephen A.

1993-01-01

27

Congenital lipoid adrenal hyperplasia  

PubMed Central

Congenital lipoid adrenal hyperplasia (lipoid CAH) is the most fatal form of CAH, as it disrupts adrenal and gonadal steroidogenesis. Most cases of lipoid CAH are caused by recessive mutations in the gene encoding steroidogenic acute regulatory protein (StAR). Affected patients typically present with signs of severe adrenal failure in early infancy and 46,XY genetic males are phenotypic females due to disrupted testicular androgen secretion. The StAR p.Q258X mutation accounts for about 70% of affected alleles in most patients of Japanese and Korean ancestry. However, it is more prevalent (92.3%) in the Korean population. Recently, some patients have been showed that they had late and mild clinical findings. These cases and studies constitute a new entity of 'nonclassic lipoid CAH'. The cholesterol side-chain cleavage enzyme, P450scc (CYP11A1), plays an essential role converting cholesterol to pregnenolone. Although progesterone production from the fetally derived placenta is necessary to maintain a pregnancy to term, some patients with P450scc mutations have recently been reported. P450scc mutations can also cause lipoid CAH and establish a recently recognized human endocrine disorder. PMID:25654062

2014-01-01

28

Focal nodular hyperplasia (FNH).  

PubMed

Focal nodular hyperplasia (FNH) is a benign tumour of the liver (hepatic tumour), which is the second most prevalent tumour of the liver (the first is hepatic hemangioma). It has a higher incidence in females, 20-40 years old, but also occurs in men and even in children. It is usually asymptomatic, rarely grows or bleeds, and has no malignant potential. This tumour was once often resected because it was difficult to distinguish from hepatic adenoma, but with modem multiphase imaging it is now diagnosed strictly by imaging criteria, and not resected. We present the case of a 78 years old man who presented to emergency room (ER) with a history of dry cough, chest pain and mild dyspnea. Chest X-ray showed ascension of the right hemidiaphragm, and a homogeneous round opacity of 6/6.2 cm in the right cardiophrenic angle. The first suspicion was of pulmonary tumor, but the final diagnosis was FNH, confirmed by CT scan. We discuss the differential diagnosis and prognosis of this entity. The particularities of the case are the presentation with respiratory symptoms and pulmonary mass, and the age of the patient. PMID:25000678

Nat, Laura; Poant?, Laura Irina

2014-01-01

29

Amphiregulin and Epidermal Hyperplasia  

PubMed Central

Overexpression of amphiregulin has been shown to induce psoriasiform changes in the skin of transgenic mice shortly after birth. Therefore, amphiregulin has been suggested as a target for anti-psoriatic therapy. To test this theory, a humanized monoclonal antibody capable of neutralizing human amphiregulin was examined for anti-proliferative effects in the human skin-severe combined immunodeficient (SCID) mouse transplant model. The anti-amphiregulin antibody reduced epidermal thickness of transplanted psoriatic skin and also inhibited the hyperplastic response that developed in nonpsoriatic skin after transplantation. The same antibody also suppressed keratinocyte proliferation in monolayer culture in a dose-dependent manner. Under the same conditions in which keratinocyte proliferation was inhibited, the antibody had little effect on proliferation of human dermal fibroblasts and no effect on type I procollagen production by these cells. Taken together, these data indicate an important role for amphiregulin in psoriatic hyperplasia and suggest that inhibition of amphiregulin activity could be an efficacious therapeutic strategy for psoriasis. These data also suggest that the hyperplastic response occurring in nonpsoriatic human skin on transplantation to the SCID mouse is mediated, in large part, by amphiregulin. PMID:15793282

Bhagavathula, Narasimharao; Nerusu, Kamalakar C.; Fisher, Gary J.; Liu, Gao; Thakur, Archana B.; Gemmell, Lorraine; Kumar, Shankar; Xu, Zenghai H.; Hinton, Paul; Tsurushita, Naoya; Landolfi, Nicholas F.; Voorhees, John J.; Varani, James

2005-01-01

30

A helium regenerative compressor  

SciTech Connect

This paper discusses the design and performance of a regenerative compressor that was developed primarily for use in cryogenic helium systems. The objectives for the development were to achieve acceptable efficiency in the machine using conventional motor and bearing technology while reducing the complexity of the system required to control contamination from the lubricants. A single stage compressor was built and tested. The compressor incorporates aerodynamically shaped blades on a 218 mm (8.6 inches) diameter impeller to achieve high efficiency. A gas-buffered non-contact shaft seal is used to oppose the diffusion of lubricant from the motor bearings into the cryogenic circuit. Since it is a rotating machine, the flow is continuous and steady, and the machine is very quiet. During performance testing with helium, the single stage machine has demonstrated a pressure ratio of 1.5 at a flow rate of 12 g/s with measured isothermal efficiencies in excess of 30%. This performance compares favorably with efficiencies generally achieved in oil flooded screw compressors.

Swift, W.L.; Nutt, W.E.; Sixsmith, H. [Creare Incorporated, Hanover, NH (United States)

1994-12-31

31

Florid reactive lymphoid hyperplasia of terminal ileum  

PubMed Central

Florid lymphoid hyperplasia in the terminal ileum can present to surgeons as an acute abdominal pain. Only few cases were reported in the literature. Our case illustrates that a rare case of florid lymphoid hyperplasia can present to surgeons as acute appendicitis. During the operation the gross appearance may mimic Crohn’s disease. A limited resection is sufficient to clinch the diagnosis of florid lymphoid hyperplasia / Crohn’s disease. In florid lymphoid hyperplasia limited resection may be curative. PMID:22242075

Kanakala, Venkatesh; Birch, Peter; Kasaraneni, Ramesh

2010-01-01

32

Adenomatoid hyperplasia of lower lip  

PubMed Central

Adenomatoid hyperplasia (AH) is an uncommon, non-neoplastic swelling on the palate caused due to hyperplasia of the mucinous acini. The lesion clinically presents as a sessile tumor-like nodule resembling pleomorphic adenoma. Histopathologic findings include lobules of enlarged mucinous acini which are filled with secretory granules. The nuclei are squeezed to the basal portions, associated with focal inflammation and ductal dilatation, and a history of trauma is often elicited. Here, we report a rare case of AH of the lower lip in a 20-year-old male patient, which mimics a mucous retention cyst or mucocele. PMID:22135695

Sharma, Gaganjot Kaur; Sharma, Manish; Vanaki, Srinivas S.

2011-01-01

33

Thymic hyperplasia in Graves’ disease  

PubMed Central

Graves’ disease is an autoimmune thyroid condition characterized by the production of autoantibodies against the thyrotropin receptor. It is known to be associated with autoimmune conditions such as myasthenia gravis, Addison's disease, type 1 diabetes mellitus, and vitiligo. We present a case of rare autoimmune association of Graves’ disease with thymic hyperplasia which regressed after treatment with antithyroid drugs. Exact pathophysiology of thymic hyperplasia in Graves’ is not well understood; it is likely to be the result of rather than the cause of Graves’ disease. PMID:23869315

Kotwal, Narendra; Singh, Yashpal; Menon, Anil; Behera, Vineet

2013-01-01

34

The Biology of Regenerative Medicine  

NSDL National Science Digital Library

The goal of regenerative medicine is to restore the structure and function of human body parts compromised by injury or disease. Regenerative medicine is a relatively new field that uses multiple approaches and has its roots largely in tissue engineering, tissue transplantation, and stem cell biology. It is becoming increasingly clear that advances in the areas of regeneration biology and developmental biology have the potential to transform regenerative medicine, and David Stocum has produced a textbook that attempts to pull everything together for the next generation of regeneration scientists. Regeneration Biology and Medicine is a terrific reference for anyone toying with the idea of moving into this field. The text offers an enormous breath of coverage of different systems currently under investigation, and Stocum provides a central theme that pits regenerative ability against fibrosis as a way to conceptually untangle the limited regenerative capacity of humans. In writing this textbook, Stocum has erected an umbrella large enough for scientists of diverse backgrounds to initiate conceptual cross-talk between those actively involved in the biology of regeneration and those targeting its clinical application.

Ken Muneoka (Tulane University;Department of Cell and Molecular Biology REV)

2007-06-05

35

Regeneratively Cooled Porous Media Jacket  

NASA Technical Reports Server (NTRS)

The fluid and heat transfer theory for regenerative cooling of a rocket combustion chamber with a porous media coolant jacket is presented. This model is used to design a regeneratively cooled rocket or other high temperature engine cooling jacket. Cooling jackets comprising impermeable inner and outer walls, and porous media channels are disclosed. Also disclosed are porous media coolant jackets with additional structures designed to transfer heat directly from the inner wall to the outer wall, and structures designed to direct movement of the coolant fluid from the inner wall to the outer wall. Methods of making such jackets are also disclosed.

Mungas, Greg (Inventor); Fisher, David J. (Inventor); London, Adam Pollok (Inventor); Fryer, Jack Merrill (Inventor)

2013-01-01

36

Regenerative Medicine: Learning from Past Examples  

E-print Network

Regenerative medicine products have characteristically shown great therapeutic potential, but limited market success. Learning from the past attempts at capturing value is critical for new and emerging regenerative medicine ...

Couto, Daniela S.

37

CALIFORNIA INSTITUTE FOR REGENERATIVE MEDICINE  

E-print Network

GRANT REGENERATIVE MEDICINE Postdoctoral Scholar Application Deadline: September 10, 2012 Instructions factor. b) Up to two postdoctoral scholars; recruited and selected by an individual faculty members based, applications for a second year of funding require a new letter from the preceptor and must include a progress

Quake, Stephen R.

38

Nondestructive test of regenerative chambers  

NASA Technical Reports Server (NTRS)

Flat panels simulating internally cooled regenerative thrust chamber walls were fabricated by electroforming, brazing and diffusion bonding to evaluate the feasibility of nondestructive evaluation techniques to detect bonds of various strength integrities. Ultrasonics, holography, and acoustic emission were investigated and found to yield useful and informative data regarding the presence of bond defects in these structures.

Malone, G. A.; Stauffis, R.; Wood, R.

1972-01-01

39

Mathematical modeling of regenerative processes.  

PubMed

In many animals, regenerative processes can replace lost body parts. Organ and tissue regeneration consequently also hold great medical promise. The regulation of regenerative processes is achieved through concerted actions of multiple organizational levels of the organism, from diffusing molecules and cellular gene expression patterns up to tissue mechanics. Our intuition is usually not adapted well to this degree of complexity and the quantitative aspects of the regulation of regenerative processes remain poorly understood. One way out of this dilemma lies in the combination of experimentation and mathematical modeling within an iterative process of model development/refinement, model predictions for novel experimental conditions, quantitative experiments testing these predictions, and subsequent model refinement. This interdisciplinary approach has already provided key insights into smaller scale processes during embryonic development and a so-far limited number of more complex regeneration processes. This review discusses selected theoretical and interdisciplinary studies and is structured along the three phases of regeneration: (1) initiation of a regeneration response, (2) tissue patterning during regenerate growth, (3) arresting the regeneration response. Moreover, we highlight the opportunities provided by extensions of mathematical models from developmental processes toward the study of related regenerative processes. PMID:24512713

Chara, Osvaldo; Tanaka, Elly M; Brusch, Lutz

2014-01-01

40

Regenerative Medicine: Past and Present  

Microsoft Academic Search

Novel therapies resulting from regenerative medicine and tissue engineering technology may offer new hope for patients with injuries, end-stage organ failure, degenerative disorders and many other clinical issues. Currently, patients suffering from diseased and injured organs are treated with transplanted organs. However, there is a shortage of donor organs that is worsening yearly as the population ages and new cases

Anthony Atala

2009-01-01

41

Atypical lymphoid hyperplasia mimicking lymphoma.  

PubMed

The distinction between reactive and neoplastic lymphoid infiltrates is a common problem in clinical practice and can be problematic. The clinical implications for both the patient and the treating clinician are profound. In this article, we discuss six of the common entities that can present as atypical lymphoid hyperplasia and thus can mimic malignant lymphomas, with emphasis on morphologic features, immunophenotypic findings, and molecular correlates that help distinguish these disorders from neoplastic conditions. The six conditions to be discussed in detail include reactive follicular hyperplasia versus follicular lymphoma; progressive transformation of germinal centers versus nodular lymphocyte predominant Hodgkin lymphoma; immunoblastic proliferations versus diffuse large B-cell lymphomas; variant forms of Castleman disease that may mimic a number of lymphoid cancers; Kikuchi's disease versus large cell lymphomas; and finally, dermatopathic lymphadenopathy and its distinction from lymph nodes showing early involvement by cutaneous T-cell lymphoma (Mycosis fungoides). PMID:19577167

Good, David J; Gascoyne, Randy D

2009-08-01

42

Hypoglycaemia in congenital adrenal hyperplasia.  

PubMed Central

Two young children with salt-losing congenital adrenal hyperplasia developed profound hypoglycaemia. In one child hypoglycaemia occurred after a prolonged fast and in the other it was precipitated by infection. This complication may be more common than the literature suggests, and emergency treatment with glucose or hydrocortisone, given by injection, should be given to any child with the disorder who suddenly or unexpectedly collapses. PMID:879852

Mackinnon, J; Grant, D B

1977-01-01

43

Cardiac Regenerative Capacity and Mechanisms  

PubMed Central

The heart holds the monumental yet monotonous task of maintaining circulation. Although cardiac function is critical to other organs and to life itself, mammals are not equipped with significant natural capacity to replace heart muscle that has been lost by injury. This deficiency plays a role in leaving millions worldwide each year vulnerable to heart failure. By contrast, certain other vertebrate species like zebrafish are strikingly good at heart regeneration. A cellular and molecular understanding of endogenous regenerative mechanisms, combined with advances in methodology to transplant cells, together project a future in which cardiac muscle regeneration can be therapeutically stimulated in injured human hearts. This review will focus on what has been discovered recently about cardiac regenerative capacity and how natural mechanisms of heart regeneration in model systems are stimulated and maintained. PMID:23057748

Kikuchi, Kazu; Poss, Kenneth D.

2013-01-01

44

The unitized regenerative fuel cell  

SciTech Connect

Fuel cells can operate on hydrogen fuel and oxygen from air. If the fuel cell is designed to also operate in reverse as an electrolyzer, then electricity can be used to convert the water back into hydrogen and oxygen. This dual function system is known as a reversible or unitized regenerative fuel cell. This is an excellent energy source in situations where weight is a concern.

NONE

1997-05-01

45

Advanced regenerative absorption refrigeration cycles  

DOEpatents

Multi-effect regenerative absorption cycles which provide a high coefficient of performance (COP) at relatively high input temperatures. An absorber-coupled double-effect regenerative cycle (ADR cycle) (10) is provided having a single-effect absorption cycle (SEA cycle) (11) as a topping subcycle and a single-effect regenerative absorption cycle (1R cycle) (12) as a bottoming subcycle. The SEA cycle (11) includes a boiler (13), a condenser (21), an expansion device (28), an evaporator (31), and an absorber (40), all operatively connected together. The 1R cycle (12) includes a multistage boiler (48), a multi-stage resorber (51), a multisection regenerator (49) and also uses the condenser (21), expansion device (28) and evaporator (31) of the SEA topping subcycle (11), all operatively connected together. External heat is applied to the SEA boiler (13) for operation up to about 500 degrees F., with most of the high pressure vapor going to the condenser (21) and evaporator (31) being generated by the regenerator (49). The substantially adiabatic and isothermal functioning of the SER subcycle (12) provides a high COP. For higher input temperatures of up to 700 degrees F., another SEA cycle (111) is used as a topping subcycle, with the absorber (140) of the topping subcycle being heat coupled to the boiler (13) of an ADR cycle (10). The 1R cycle (12) itself is an improvement in that all resorber stages (50b-f) have a portion of their output pumped to boiling conduits (71a-f) through the regenerator (49), which conduits are connected to and at the same pressure as the highest pressure stage (48a) of the 1R multistage boiler (48).

Dao, Kim (14 Nace Ave., Piedmont, CA 94611)

1990-01-01

46

Regenerative glycosylation under nucleophilic catalysis  

PubMed Central

This article describes 3,3-difluoroxindole (HOFox) – mediated glycosylation. The uniqueness of this approach is that both the in-situ synthesis of 3,3-difluoro-3Hindol-2-yl (OFox) glycosyl donors and activation thereof can be conducted in a regenerative fashion as is a typical reaction performed under nucleophilic catalysis. Only a catalytic amount of the OFox imidate donor and a Lewis acid activator are present in the reaction medium. The OFox imidate donor is constantly regenerated upon its consumption until all glycosyl acceptor has reacted. PMID:24393099

Nigudkar, Swati. S.; Stine, Keith J.; Demchenko, Alexei V.

2014-01-01

47

XLVIII. Heat regeneration and regenerative cycles  

Microsoft Academic Search

The following paper sets out to investigate the possibilities in heat regenerative cycles, particularly in relation to internal combustion turbine development. A new type of regenerative cycle is proposed, the analysis of which indicates the independence of turbine thermal efficiency on compression ratio. Actually it appears that the thermal efficiency should be higher the lower the compression ratio. The efficiency

Wm. J. Walker

1927-01-01

48

REGEN: Ancestral Genome Reconstruction for Bacteria  

PubMed Central

Ancestral genome reconstruction can be understood as a phylogenetic study with more details than a traditional phylogenetic tree reconstruction. We present a new computational system called REGEN for ancestral bacterial genome reconstruction at both the gene and replicon levels. REGEN reconstructs gene content, contiguous gene runs, and replicon structure for each ancestral genome. Along each branch of the phylogenetic tree, REGEN infers evolutionary events, including gene creation and deletion and replicon fission and fusion. The reconstruction can be performed by either a maximum parsimony or a maximum likelihood method. Gene content reconstruction is based on the concept of neighboring gene pairs. REGEN was designed to be used with any set of genomes that are sufficiently related, which will usually be the case for bacteria within the same taxonomic order. We evaluated REGEN using simulated genomes and genomes in the Rhizobiales order. PMID:24704978

Yang, Kuan; Heath, Lenwood S.; Setubal, João C.

2012-01-01

49

Unitized regenerative fuel cell system  

NASA Technical Reports Server (NTRS)

A Unitized Regenerative Fuel Cell system uses heat pipes to convey waste heat from the fuel cell stack to the reactant storage tanks. The storage tanks act as heat sinks/sources and as passive radiators of the waste heat from the fuel cell stack. During charge up, i.e., the electrolytic process, gases are conveyed to the reactant storage tanks by way of tubes that include dryers. Reactant gases moving through the dryers give up energy to the cold tanks, causing water vapor in with the gases to condense and freeze on the internal surfaces of the dryer. During operation in its fuel cell mode, the heat pipes convey waste heat from the fuel cell stack to the respective reactant storage tanks, thereby heating them such that the reactant gases, as they pass though the respective dryers on their way to the fuel cell stacks retrieve the water previously removed.

Burke, Kenneth A. (Inventor)

2008-01-01

50

Regenerative Therapies for Diabetic Microangiopathy  

PubMed Central

Hyperglycaemia occurring in diabetes is responsible for accelerated arterial remodeling and atherosclerosis, affecting the macro- and the microcirculatory system. Vessel injury is mainly related to deregulation of glucose homeostasis and insulin/insulin-precursors production, generation of advanced glycation end-products, reduction in nitric oxide synthesis, and oxidative and reductive stress. It occurs both at extracellular level with increased calcium and matrix proteins deposition and at intracellular level, with abnormalities of intracellular pathways and increased cell death. Peripheral arterial disease, coronary heart disease, and ischemic stroke are the main causes of morbidity/mortality in diabetic patients representing a major clinical and economic issue. Pharmacological therapies, administration of growth factors, and stem cellular strategies are the most effective approaches and will be discussed in depth in this comprehensive review covering the regenerative therapies of diabetic microangiopathy. PMID:22536216

Bassi, Roberto; Trevisani, Alessio; Tezza, Sara; Ben Nasr, Moufida; Gatti, Francesca; Vergani, Andrea; Farina, Antonio; Fiorina, Paolo

2012-01-01

51

Dissecting the mechanisms of Notch induced hyperplasia  

PubMed Central

The outcome of the Notch pathway on proliferation depends on cellular context, being growth promotion in some, including several cancers, and growth inhibition in others. Such disparate outcomes are evident in Drosophila wing discs, where Notch overactivation causes hyperplasia despite having localized inhibitory effects on proliferation. To understand the underlying mechanisms, we have used genomic strategies to identify the Notch-CSL target genes directly activated during wing disc hyperplasia. Among them were genes involved in both autonomous and non-autonomous regulation of proliferation, growth and cell death, providing molecular explanations for many characteristics of Notch induced wing disc hyperplasia previously reported. The Notch targets exhibit different response patterns, which are shaped by both positive and negative feed-forward regulation between the Notch targets themselves. We propose, therefore, that both the characteristics of the direct Notch targets and their cross-regulatory relationships are important in coordinating the pattern of hyperplasia. PMID:23232763

Djiane, Alexandre; Krejci, Alena; Bernard, Frédéric; Fexova, Silvie; Millen, Katherine; Bray, Sarah J

2013-01-01

52

Perivascular cells for regenerative medicine.  

PubMed

Mesenchymal stem/stromal cells (MSC) are currently the best candidate therapeutic cells for regenerative medicine related to osteoarticular, muscular, vascular and inflammatory diseases, although these cells remain heterogeneous and necessitate a better biological characterization. We and others recently described that MSC originate from two types of perivascular cells, namely pericytes and adventitial cells and contain the in situ counterpart of MSC in developing and adult human organs, which can be prospectively purified using well defined cell surface markers. Pericytes encircle endothelial cells of capillaries and microvessels and express the adhesion molecule CD146 and the PDGFR?, but lack endothelial and haematopoietic markers such as CD34, CD31, vWF (von Willebrand factor), the ligand for Ulex europaeus 1 (UEA1) and CD45 respectively. The proteoglycan NG2 is a pericyte marker exclusively associated with the arterial system. Besides its expression in smooth muscle cells, smooth muscle actin (?SMA) is also detected in subsets of pericytes. Adventitial cells surround the largest vessels and, opposite to pericytes, are not closely associated to endothelial cells. Adventitial cells express CD34 and lack ?SMA and all endothelial and haematopoietic cell markers, as for pericytes. Altogether, pericytes and adventitial perivascular cells express in situ and in culture markers of MSC and display capacities to differentiate towards osteogenic, adipogenic and chondrogenic cell lineages. Importantly, adventitial cells can differentiate into pericyte-like cells under inductive conditions in vitro. Altogether, using purified perivascular cells instead of MSC may bring higher benefits to regenerative medicine, including the possibility, for the first time, to use these cells uncultured. PMID:22882758

Crisan, Mihaela; Corselli, Mirko; Chen, William C W; Péault, Bruno

2012-12-01

53

Gingival enlargement in partial hemifacial hyperplasia  

PubMed Central

Hemifacial hypertrophy is a rare developmental disorder, characterized by unilateral enlargement of facial tissues. The hemifacial hyperplasia is classified as true hemifacial hypertrophy and partial hemifacial hypertrophy. It is unilateral enlargement of viscerocranial condition in which not all structures are enlarged. We present a rare case of gingival enlargement in partial hemifacial hyperplasia highlighting the clinical and radiological findings with the corrective treatment offered for gingival enlargement.

Jagtap, Rasika Ravindra; Deshpande, Gaurav Shekhar

2014-01-01

54

Endometrial Stromal Hyperplasia: An Underrecognized Condition  

PubMed Central

Hyperplasia of the endometrial stroma is a poorly recognized lesion, lacking widespread recognition with most, if not all, such cases sequestrated in the literature as endometrial stromal nodules or low-grade endometrial stromal sarcomas. In this paper, we describe three examples of “endometrial stromal hyperplasia” which have a remarkable morphological similarity with the normally proliferating endometrial stroma and the endometrial stromal neoplasms, but which also possess subtle, but sufficient, differences to justify their taxonomic separation. PMID:23710401

Koutsougeras, Gerasimos; Giatromanolaki, Alexandra

2013-01-01

55

Regenerative medicine applications in combat casualty care.  

PubMed

The purpose of this report is to describe regenerative medicine applications in the management of complex injuries sustained by service members injured in support of the wars in Afghanistan and Iraq. Improvements in body armor, resuscitative techniques and faster transport have translated into increased patient survivability and more complex wounds. Combat-related blast injuries have resulted in multiple extremity injuries, significant tissue loss and amputations. Due to the limited availability and morbidity associated with autologous tissue donor sites, the introduction of regenerative medicine has been critical in managing war extremity injuries with composite massive tissue loss. Through case reports and clinical images, this report reviews the application of regenerative medicine modalities employed to manage combat-related injuries. It illustrates that the novel use of hybrid reconstructions combining traditional and regenerative medicine approaches are an effective tool in managing wounds. Lessons learned can be adapted to civilian care. PMID:24750059

Fleming, Mark E; Bharmal, Husain; Valerio, Ian

2014-03-01

56

Current overview on challenges in regenerative endodontics  

PubMed Central

Introduction: Regenerative endodontics provides hope of converting the non-vital tooth into vital once again. It focuses on substituting traumatized and pathological pulp with functional pulp tissue. Current regenerative procedures successfully produce root development but still fail to re-establish real pulp tissue and give unpredictable results. There are several drawbacks that need to be addressed to improve the quality and efficiency of the treatment. Aim: The aim of this review article is to discuss major priorities that ought to be dealt before applications of regenerative endodontics flourish the clinical practice. Materials and Methods: A web-based research on MEDLINE was done using filter terms Review, published in the last 10 years and Dental journals. Keywords used for research were “regenerative endodontics,” “dental stem cells,” “growth factor regeneration,” “scaffolds,” and “challenges in regeneration.” This review article screened about 150 articles and then the relevant information was compiled. Results: Inspite of the impressive growth in regenerative endodontic field, there are certain loopholes in the existing treatment protocols that might sometimes result in undesired and unpredictable outcomes. Conclusion: Considerable research and development efforts are required to improve and update existing regenerative endodontic strategies to make it an effective, safe, and biological mode to save teeth. PMID:25657518

Bansal, Ramta; Jain, Aditya; Mittal, Sunandan

2015-01-01

57

Regenerative fuel cell engineering - FY99  

SciTech Connect

The authors report the work conducted by the ESA-EPE Fuel Cell Engineering Team at Los Alamos National Laboratory during FY99 on regenerative fuel cell system engineering. The work was focused on the evaluation of regenerative fuel cell system components obtained through the RAFCO program. These components included a 5 kW PEM electrolyzer, a two-cell regenerative fuel cell stack, and samples of the electrolyzer membrane, anode, and cathode. The samples of the electrolyzer membrane, anode, and cathode were analyzed to determine their structure and operating characteristics. Tests were conducted on the two-cell regenerative fuel cell stack to characterize its operation as an electrolyzer and as a fuel cell. The 5 kW PEM electrolyzer was tested in the Regenerative Fuel Cell System Test Facility. These tests served to characterize the operation of the electrolyzer and, also, to verify the operation of the newly completed test facility. Future directions for this work in regenerative fuel cell systems are discussed.

Michael A. Inbody; Rodney L. Borup; James C. Hedstrom; Jose Tafoya; Byron Morton; Lois Zook; Nicholas E. Vanderborgh

2000-01-01

58

Staged regenerative sorption heat pump  

NASA Technical Reports Server (NTRS)

A regenerative adsorbent heat pump process and system for cooling and heating a space. A sorbent is confined in a plurality of compressors of which at least four are first stage and at least four are second stage. The first stage operates over a first pressure region and the second stage over a second pressure region which is higher than the first. Sorbate from the first stage enters the second stage. The sorbate loop includes a condenser, expansion valve, evaporator and the compressors. A single sorbate loop can be employed for single-temperature-control such as air conditioning and heating. Two sorbate loops can be used for two-temperature-control as in a refrigerator and freezer. The evaporator temperatures control the freezer and refrigerator temperatures. Alternatively the refrigerator temperature can be cooled by the freezer with one sorbate loop. A heat transfer fluid is circulated in a closed loop which includes a radiator and the compressors. Low temperature heat is exhausted by the radiator. High temperature heat is added to the heat transfer fluid entering the compressors which are desorbing vapor. Heat is transferred from compressors which are sorbing vapor to the heat transfer fluid, and from the heat transfer fluid to the compressors which are desorbing vapor. Each compressor is subjected to the following phases, heating to its highest temperature, cooling down from its highest temperature, cooling to its lowest temperature, and warming up from its lowest temperature. The phases are repeated to complete a cycle and regenerate heat.

Jones, Jack A. (Inventor)

1995-01-01

59

High power regenerative laser amplifier  

DOEpatents

A regenerative amplifier design capable of operating at high energy per pulse, for instance, from 20-100 Joules, at moderate repetition rates, for instance from 5-20 Hertz is provided. The laser amplifier comprises a gain medium and source of pump energy coupled with the gain medium; a Pockels cell, which rotates an incident beam in response to application of a control signal; an optical relay system defining a first relay plane near the gain medium and a second relay plane near the rotator; and a plurality of reflectors configured to define an optical path through the gain medium, optical relay and Pockels cell, such that each transit of the optical path includes at least one pass through the gain medium and only one pass through the Pockels cell. An input coupler, and an output coupler are provided, implemented by a single polarizer. A control circuit coupled to the Pockels cell generates the control signal in timed relationship with the input pulse so that the input pulse is captured by the input coupler and proceeds through at least one transit of the optical path, and then the control signal is applied to cause rotation of the pulse to a polarization reflected by the polarizer, after which the captured pulse passes through the gain medium at least once more and is reflected out of the optical path by the polarizer before passing through the rotator again to provide an amplified pulse.

Miller, John L. (Livermore, CA); Hackel, Lloyd A. (Livermore, CA); Dane, Clifford B. (Dublin, CA); Zapata, Luis E. (Livermore, CA)

1994-01-01

60

High power regenerative laser amplifier  

DOEpatents

A regenerative amplifier design capable of operating at high energy per pulse, for instance, from 20-100 Joules, at moderate repetition rates, for instance from 5-20 Hertz is provided. The laser amplifier comprises a gain medium and source of pump energy coupled with the gain medium; a Pockels cell, which rotates an incident beam in response to application of a control signal; an optical relay system defining a first relay plane near the gain medium and a second relay plane near the rotator; and a plurality of reflectors configured to define an optical path through the gain medium, optical relay and Pockels cell, such that each transit of the optical path includes at least one pass through the gain medium and only one pass through the Pockels cell. An input coupler, and an output coupler are provided, implemented by a single polarizer. A control circuit coupled to the Pockels cell generates the control signal in timed relationship with the input pulse so that the input pulse is captured by the input coupler and proceeds through at least one transit of the optical path, and then the control signal is applied to cause rotation of the pulse to a polarization reflected by the polarizer, after which the captured pulse passes through the gain medium at least once more and is reflected out of the optical path by the polarizer before passing through the rotator again to provide an amplified pulse. 7 figures.

Miller, J.L.; Hackel, L.A.; Dane, C.B.; Zapata, L.E.

1994-02-08

61

Clinical imaging in regenerative medicine.  

PubMed

In regenerative medicine, clinical imaging is indispensable for characterizing damaged tissue and for measuring the safety and efficacy of therapy. However, the ability to track the fate and function of transplanted cells with current technologies is limited. Exogenous contrast labels such as nanoparticles give a strong signal in the short term but are unreliable long term. Genetically encoded labels are good both short- and long-term in animals, but in the human setting they raise regulatory issues related to the safety of genomic integration and potential immunogenicity of reporter proteins. Imaging studies in brain, heart and islets share a common set of challenges, including developing novel labeling approaches to improve detection thresholds and early delineation of toxicity and function. Key areas for future research include addressing safety concerns associated with genetic labels and developing methods to follow cell survival, differentiation and integration with host tissue. Imaging may bridge the gap between cell therapies and health outcomes by elucidating mechanisms of action through longitudinal monitoring. PMID:25093889

Naumova, Anna V; Modo, Michel; Moore, Anna; Murry, Charles E; Frank, Joseph A

2014-08-01

62

JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE RESEARCH ARTICLE J Tissue Eng Regen Med (2010).  

E-print Network

JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE RESEARCH ARTICLE J Tissue Eng Regen Med Developing a tissue-engineered model of the human bronchiole Cheryl Miller1*, Steven George2 and Laura by anatomical, physiological and functional changes. A tissue-engineered model of bronchiole remodelling

George, Steven C.

63

Therapeutic potential of nanoceria in regenerative medicine.  

SciTech Connect

Tissue engineering and regenerative medicine aim to achieve functional restoration of tissue or cells damaged through disease, aging or trauma. Advancement of tissue engineering requires innovation in the field of 3D scaffolding, and functionalization with bioactive molecules. Nanotechnology offers advanced materials with patterned nano-morphologies for cell growth and different molecular substrates which can support cell survival and functions. Cerium oxide nanoparticles (nanoceria) can control intracellular as well as extracellular reactive oxygen and nitrogen species. Recent findings suggest that nanoceria can enhance long-term cell survival, enable cell migration and proliferation, and promote stem cell differentiation. Moreover, the self-regenerative property of nanoceria permits a small dose to remain catalytically active for extended time. This review summarizes the possibilities and applications of nanoceria in the field of tissue engineering and regenerative medicine.

Das, Soumen; Chigurupati, Srinivasulu; Dowding, Janet; Munusamy, Prabhakaran; Baer, Donald R.; McGinnis, James F.; Mattson, Mark P.; Self, William; Seal, Sudipta

2014-11-14

64

Combined hydraulic and regenerative braking system  

DOEpatents

A combined hydraulic and regenerative braking system and method for an electric vehicle, with the braking system being responsive to the applied hydraulic pressure in a brake line to control the braking of the vehicle to be completely hydraulic up to a first level of brake line pressure, to be partially hydraulic at a constant braking force and partially regenerative at a linearly increasing braking force from the first level of applied brake line pressure to a higher second level of brake line pressure, to be partially hydraulic at a linearly increasing braking force and partially regenerative at a linearly decreasing braking force from the second level of applied line pressure to a third and higher level of applied line pressure, and to be completely hydraulic at a linearly increasing braking force from the third level to all higher applied levels of line pressure.

Venkataperumal, Rama R. (Troy, MI); Mericle, Gerald E. (Mount Clemens, MI)

1981-06-02

65

Atypical Sweat Duct Hyperplasia Accompanying Keratoacanthoma  

Microsoft Academic Search

25 cases of atypical sweat duct proliferation in association with cutaneous tumors are described. 20 of these were keratoacanthomas. The compression of the duct either in its dermal or intraepidermal portion is considered to be the etiology. Similar changes are seen with decubitus ulcer and stasis dermatitis. Atypical sweat duct hyperplasia may be useful as an extra aid in the

Daniel J. Santa Cruz; Kathryn Clausen

1977-01-01

66

Functionalized Nanostructures with Application in Regenerative Medicine  

PubMed Central

In the last decade, both regenerative medicine and nanotechnology have been broadly developed leading important advances in biomedical research as well as in clinical practice. The manipulation on the molecular level and the use of several functionalized nanoscaled materials has application in various fields of regenerative medicine including tissue engineering, cell therapy, diagnosis and drug and gene delivery. The themes covered in this review include nanoparticle systems for tracking transplanted stem cells, self-assembling peptides, nanoparticles for gene delivery into stem cells and biomimetic scaffolds useful for 2D and 3D tissue cell cultures, transplantation and clinical application. PMID:22489186

Perán, Macarena; García, María A.; López-Ruiz, Elena; Bustamante, Milán; Jiménez, Gema; Madeddu, Roberto; Marchal, Juan A.

2012-01-01

67

The mission of the UW Stem Cell and Regenerative Medi-  

E-print Network

. They include Stem Cell Bioengineering, Cardiovascular Regeneration, Musculoskeletal Regen- eration, MolecularSCRMCNotes The mission of the UW Stem Cell and Regenerative Medi- cine Center is to advance the science of stem cell biology and foster breakthroughs in regenerative medicine through faculty

68

Bit Error Rate Comparison of Repeater and Regenerative Communication Satellites  

Microsoft Academic Search

We evaluate and compare bit error rates for conventional (linear and nonlinear) repeater satellites and regenerative satellites. This work is based on a new formulation for error rates using the generalized moment technique for numerical evaluation of error rates. Both coherent MPSK and noncoherent MFSK modulations are considered with regenerative satellites. The results show that regenerative satellites are especially effective

T. Huang; J. Omura; L. Biederman

1980-01-01

69

Regenerative fuel cell systems for project pathfinder  

NASA Technical Reports Server (NTRS)

The objectives of a surface power program, an element of the exploration thrust of the Pathfinder project, and plans for meeting them are outlined. Technological assessment and tradeoff studies of fuel cell and electrolyzer technologies suitable for use in a regenerative fuel cell are described. The viability of proton exchange membranes (PEM) in meeting the system requirements is discussed.

Huff, J. R.; Hedstrom, J.; Vanderborgh, N. E.; Prokopius, P.

1989-01-01

70

Regenerative Studies: College Community and Community College.  

ERIC Educational Resources Information Center

This case study applies principles derived from the Center for Regenerative Studies (CRS) to a community college in North Carolina. CRS, on the campus of California State Polytechnic Institute (California), is dedicated to the education, demonstration, and research of degenerative systems in the areas of shelter, food production, energy, water and…

Woltz, Mary G.

71

Simulations of the LANL regenerative amplifier FEL  

SciTech Connect

The LANL regenerative amplifier FEL is designed to produce an average output power of 1 kW. Simulations study the transverse effects due to guiding by the intense electron beam and feedback. These simulations coupled with experimental measurements can be used to improve future high-power FEL designs.

Kesselring, M.; Colson, W.B.; Wong, R.K. [Naval Postgraduate School, Monterey, CA (United States). Physics Dept.; Sheffield, R.L. [Los Alamos National Lab., NM (United States)

1997-08-01

72

Stem Cell Senescence and Regenerative Paradigms  

Microsoft Academic Search

The term “cellular senescence” denotes a cellular response to several stressors that results in irreversible growth arrest, alterations of the gene expression profile, epigenetic modifications, and an altered secretome, all of which eventually impair the reparative properties of primitive cells, adding a layer of complexity to the field of regenerative medicine. The purpose of this review is to illustrate how

A P Beltrami; D Cesselli; C A Beltrami

2012-01-01

73

[Non-cirrhotic portal hypertension presented by acute upper gastrointestinal bleeding 7 years after oxaliplatin-chemotherapy].  

PubMed

After having received adjuvant FOLFOX treatment consisting of oxaliplatin, folinic acid and fluoruracil following hemicolectomy in colon cancer 7 years ago, the findings of non-cirrhotic portal hypertension presented by acute upper gastrointestinal bleeding in a 49-year old woman were interpreted as oxaliplatin-associated. Imaging techniques, hepatic venous pressure measurement and liver biopsy supported pre-sinusoidal damage due to NRH (nodular regenerative hyperplasia) as the underlying cause, even though histological findings were moderate. Following primary endoscopic treatment, a stable condition has thus far been achievable with standard drug therapy. PMID:25026007

Schwarz, S; Suppan, M; Höbling, W; Grünberger, A; Nömeyer, R; Hubner, D; Knoflach, P

2014-07-01

74

Intractable verrucous hyperplasia: a surgically corrected case.  

PubMed

Skin problems commonly occur after lower limb amputation. Wart-like lesions of verrucous hyperplasia is one such skin anomaly that develops on the residual-limb. The process is reversible if external compression in combination with adequate control of bacterial infection and edema is applied. Prosthetic adjustments usually help with this condition. However, we experienced an intractable verrucous hyperplasia case in a 65-year-old female. She complained of a painful, oozing, verrucous papule at the amputation site. Despite management with typical treatment procedures, the lesion worsened. Surgical treatment was therefore carried out. This case demonstrated that an intractable case is possible despite appropriate management and sometimes surgical correction is necessary. PMID:25479281

Chang, Ji Hea; Moon, Hee Bong; Kim, Chang Jae; Nam, Kiyeun; Lee, Ho Jun; Kwon, Bum Sun; Park, Jin-Woo

2014-12-01

75

Sebaceous gland hyperplasia of the foreskin.  

PubMed

Two men, aged in their 20s, presented with multiple, soft, rounded papules on the prepuce. The lesions were centrally umbilicated, resembling molluscum contagiosum, but clearly distinct from Tyson's glands. Surface microscopy showed well-defined, milky-white, bag-shaped structures, which under histological examination were found to be sebaceous glands with various features of hyperplasia. A lymphocytic T-cell infiltrate, closely associated with progressive degeneration and destruction of the sebocytes, was visible around the glands. In the differential diagnosis of penile papular lesions, this unusual clinical presentation supported by dermatoscopy is consistent with preputial sebaceous gland hyperplasia. As both patients had a prominent T-cell infiltration, it is possible that under inflammatory stimulation, sebaceous glands undergo hypertrophy and gradual central involution. PMID:19077090

Ena, P; Origa, D; Massarelli, G

2009-04-01

76

Fertility in patients with congenital adrenal hyperplasia.  

PubMed

Congenital adrenal hyperplasia (CAH) is the most frequently encountered genetic steroid disorder affecting fertility. Steroid hormones play a crucial role in sexual development and reproductive function; patients with either 21- hydroxylase or 11?-hydroxylase deficiency thus face immense challenges to their fertility. Given the relevance of CAH in reproductive medicine as well as the diagnostic challenges posed by the phenotypic overlap with polycystic ovary syndrome, we review the reproductive pahophysiology of both classic and nonclassic CAH and present contemporary treatment options. PMID:24355046

Reichman, David E; White, Perrin C; New, Maria I; Rosenwaks, Zev

2014-02-01

77

Saw Palmetto for Benign Prostatic Hyperplasia  

Microsoft Academic Search

In this double-blind trial, we randomly assigned 225 men over the age of 49 years who had moderate-to-severe symptoms of benign prostatic hyperplasia to one year of treatment with saw palmetto extract (160 mg twice a day) or placebo. The pri- mary outcome measures were changes in the scores on the American Urological Association Symptom Index (AUASI) and the maximal

Stephen Bent; Christopher Kane; Katsuto Shinohara; John Neuhaus; Esther S. Hudes; Harley Goldberg; Andrew L. Avins

2006-01-01

78

Regenerative nanomedicines: an emerging investment prospective?  

PubMed Central

Cells respond to their structural surrounding and within nanostructures exhibit unique proliferative and differentiation properties. The application of nanotechnologies to the field of regenerative medicine offers the potential to direct cell fate, target the delivery of cells and reduce immune rejection (via encapsulation), thereby supporting the development of regenerative medicines. The overall objective of any therapy is the delivery of the product not just into the clinic but also to patients on a routine basis. Such a goal typically requires a commercial vehicle and substantial levels of investment in scientific, clinical, regulatory and business expertise, resources, time and funding. Therefore, this paper focuses on some of the challenges facing this emerging industry, including investment by the venture capital community. PMID:20826478

Prescott, Catherine

2010-01-01

79

Induced Pluripotent Stem Cells for Regenerative Medicine  

PubMed Central

With the discovery of induced pluripotent stem (iPS) cells, it is now possible to convert differentiated somatic cells into multipotent stem cells that have the capacity to generate all cell types of adult tissues. Thus, there is a wide variety of applications for this technology, including regenerative medicine, in vitro disease modeling, and drug screening/discovery. Although biological and biochemical techniques have been well established for cell reprogramming, bioengineering technologies offer novel tools for the reprogramming, expansion, isolation, and differentiation of iPS cells. In this article, we review these bioengineering approaches for the derivation and manipulation of iPS cells and focus on their relevance to regenerative medicine. PMID:24905879

Hirschi, Karen K.; Li, Song; Roy, Krishnendu

2014-01-01

80

Electrospun Silk Biomaterial Scaffolds for Regenerative Medicine  

PubMed Central

Electrospinning is a versatile technique that enables the development of nanofiber-based biomaterial scaffolds. Scaffolds can be generated that are useful for tissue engineering and regenerative medicine since they mimic the nanoscale properties of certain fibrous components of the native extracellular matrix in tissues. Silk is a natural protein with excellent biocompatibility, remarkable mechanical properties as well as tailorable degradability. Integrating these protein polymer advantages with electrospinning results in scaffolds with combined biochemical, topographical and mechanical cues with versatility for a range of biomaterial, cell and tissue studies and applications. This review covers research related to electrospinning of silk, including process parameters, post treatment of the spun fibers, functionalization of nanofibers, and the potential applications for these material systems in regenerative medicine. Research challenges and future trends are also discussed. PMID:19643154

Zhang, Xiaohui; Reagan, Michaela R; Kaplan, David L.

2009-01-01

81

Bioactive supramolecular Peptide nanofibers for regenerative medicine.  

PubMed

Recent advances in understanding of cell-matrix interactions and the role of the extracellular matrix (ECM) in regulation of cellular behavior have created new perspectives for regenerative medicine. Supramolecular peptide nanofiber systems have been used as synthetic scaffolds in regenerative medicine applications due to their tailorable properties and ability to mimic ECM proteins. Through designed bioactive epitopes, peptide nanofiber systems provide biomolecular recognition sites that can trigger specific interactions with cell surface receptors. The present Review covers structural and biochemical properties of the self-assembled peptide nanofibers for tissue regeneration, and highlights studies that investigate the ability of ECM mimetic peptides to alter cellular behavior including cell adhesion, proliferation, and/or differentiation. PMID:24574311

Arslan, Elif; Garip, I Ceren; Gulseren, Gulcihan; Tekinay, Ayse B; Guler, Mustafa O

2014-09-01

82

Low-temperature thermally regenerative electrochemical system  

DOEpatents

A thermally regenerative electrochemical system is described including an electrochemical cell with two water-based electrolytes separated by an ion exchange membrane, at least one of the electrolytes containing a complexing agent and a salt of a multivalent metal whose respective order of potentials for a pair of its redox couples is reversible by a change in the amount of the ocmplexing agent in the electrolyte, the complexing agent being removable by distillation to cause the reversal.

Loutfy, R.O.; Brown, A.P.; Yao, N.P.

1982-04-21

83

Low temperature thermally regenerative electrochemical system  

DOEpatents

A thermally regenerative electrochemical system including an electrochemical cell with two water-based electrolytes separated by an ion exchange membrane, at least one of the electrolytes containing a complexing agent and a salt of a multivalent metal whose respective order of potentials for a pair of its redox couples is reversible by a change in the amount of the complexing agent in the electrolyte, the complexing agent being removable by distillation to cause the reversal.

Loutfy, Raouf O. (Tucson, AZ); Brown, Alan P. (Bolingbrook, IL); Yao, Neng-Ping (Clarendon Hills, IL)

1983-01-01

84

Secular Humanist Bioethics and Regenerative Medicine  

Microsoft Academic Search

\\u000a As Daniel Callahan perceptively observed some 20 years ago, issues and dilemmas in bioethics might be new as a result of remarkable\\u000a advances in biomedical science, but the moral questions they raise are “among the oldest that human beings have asked themselves”\\u000a (Callahan, 2004, p. 278). Regenerative Medicine is a cutting edge medicine, devoted to the repair of damaged, diseased,

Ping-Cheung Lo

85

Turbo Decoder Development in Regenerative Communications Satellites  

Microsoft Academic Search

For regenerative telecom satellite systems, the turbo decoder has become a basic component of the on-board processing (OBP). This paper presents the algorithm selection choices and the test bench policy during the design process of a communication system critical block such as a turbo decoder compliant with the DVB-RCS standard (digital video broadcast-return channel satellite). The architecture, based on the

B. Lestriez; E. R. Perez

2006-01-01

86

Optimization of an irreversible Stirling regenerative cycle  

NASA Astrophysics Data System (ADS)

In this work a Stirling regenerative cycle with some irreversibilities is analyzed. The analyzed irreversibilities are located at the heat exchangers. They receive a finite amount of heat and heat leakage occurs between both reservoirs. Using this model, power and the efficiency at maximum power are obtained. Some optimal design parameters for the exchanger heat areas and thermal conductances are presented. The relation between the power, efficiency and the results obtained are shown graphically.

Aragón-González, G.; Cano-Bianco, M.; León-Galicia, A.; Rivera-Camacho, J. M.

2015-01-01

87

Genetics Home Reference: Congenital adrenal hyperplasia due to 11-beta-hydroxylase deficiency  

MedlinePLUS

... disorder catalog Conditions > Congenital adrenal hyperplasia due to 11-beta-hydroxylase deficiency On this page: Description Genetic ... 2011 What is congenital adrenal hyperplasia due to 11-beta-hydroxylase deficiency? Congenital adrenal hyperplasia (CAH) due ...

88

Role of Inflammation in Benign Prostatic Hyperplasia  

PubMed Central

Inflammation of the prostate may represent a mechanism for hyperplastic changes to occur in the prostate. There are a variety of growth factors and cytokines that may lead to a proinflammatory process within the prostate. There are several proposed mechanisms that lead to both the intrinsic and extrinsic basis of inflammation. Prostatic inflammation may represent an important factor in influencing prostatic growth and progression of symptoms. This article reviews the recent literature on inflammation leading to chronic prostatic diseases, such as benign prostatic hyperplasia. PMID:22110398

Chughtai, Bilal; Lee, Richard; Te, Alexis; Kaplan, Steven

2011-01-01

89

The Impact of Biomechanics in Tissue Engineering and Regenerative Medicine  

E-print Network

Biomechanical factors profoundly influence the processes of tissue growth, development, maintenance, degeneration, and repair. Regenerative strategies to restore damaged or diseased tissues in vivo and create living tissue ...

Butler, David L.

90

Platelet rich fibrin - a novel acumen into regenerative endodontic therapy  

PubMed Central

Research into regenerative dentistry has added impetus onto the field of molecular biology. It can be documented as a prototype shift in the therapeutic armamentarium for dental disease. Regenerative endodontic procedures are widely being added to the current armamentarium of pulp therapy procedures. The regenerative potential of platelets has been deliberated. A new family of platelet concentrates called the platelet rich fibrin (PRF) has been recently used by several investigators and has shown application in diverse disciplines of dentistry. This paper is intended to add light on the various prospects of PRF and clinical insights to regenerative endodontic therapy. PMID:24516822

Sharma, Krishna

2014-01-01

91

Genetics of primary macronodular adrenal hyperplasia.  

PubMed

ACTH-independent macronodular adrenal hyperplasia is a rare cause of Cushing's syndrome (CS), accounting for <2% of all endogenous CS cases; however it is more frequently identified incidentally with sub-clinical cortisol secretion. Recently, cortisol secretion has been shown to be regulated by ectopic corticotropin, which is in turn produced by clusters of steroidogenic cells of the hyperplastic adrenal nodules. Hence, the term 'ACTH-independent' is not entirely appropriate for this disorder. Accordingly, the disease is designated primary macronodular adrenal hyperplasia (PMAH) in this review article. The means by which cortisol production is regulated in PMAH despite the suppressed levels of ACTH of pituitary origin is exceedingly complex. Several molecular events have been proposed to explain the enhanced cortisol secretion, increased cell proliferation, and nodule formation in PMAH. Nonetheless, the precise sequence of events and the molecular mechanisms underlying this condition remain unclear. The purpose of this review is therefore to present new insights on the molecular and genetic profile of PMAH pathophysiology, and to discuss the implications for disease progression. PMID:25472909

Fragoso, Maria Candida Barisson Villares; Alencar, Guilherme Asmar; Lerario, Antonio Marcondes; Bourdeau, Isabelle; Almeida, Madson Queiroz; Mendonca, Berenice Bilharinho; Lacroix, André

2015-01-01

92

Conditional deletion of Pten causes bronchiolar hyperplasia.  

PubMed

Tumor suppressor phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a lipid phosphatase that regulates multiple cellular processes including cell polarity, migration, proliferation, and carcinogenesis. In this work, we demonstrate that conditional deletion of Pten (Pten(Delta/Delta)) in the respiratory epithelial cells of the developing mouse lung caused epithelial cell proliferation and hyperplasia as early as 4 to 6 weeks of age. While bronchiolar cell differentiation was normal, as indicated by beta-tubulin and FOXJ1 expression in ciliated cells and by CCSP expression in nonciliated cells, cell proliferation (detected by expression of Ki-67, phospho-histone-H3, and cyclin D1) was increased and associated with activation of the AKT/mTOR survival pathway. Deletion of Pten caused papillary epithelial hyperplasia characterized by a hypercellular epithelium lining papillae with fibrovascular cores that protruded into the airway lumens. Cell polarity, as assessed by subcellular localization of cadherin, beta-catenin, and zonula occludens-1, was unaltered. PTEN is required for regulation of epithelial cell proliferation in the lung and for the maintenance of the normal simple columnar epithelium characteristics of bronchi and bronchioles. PMID:17921358

Davé, Vrushank; Wert, Susan E; Tanner, Tiffany; Thitoff, Angela R; Loudy, Dave E; Whitsett, Jeffrey A

2008-03-01

93

Regenerative Electronic Biosensors Using Supramolecular Approaches  

PubMed Central

A supramolecular interface for Si nanowire FETs has been developed with the aim of creating regenerative electronic biosensors. The key to the approach are Si-NWs functionalized with ?-Cyclodextrin (?-CD), to which receptor moieties can be attached with an orthogonal supramolecular linker. Here we demonstrate full recycling using the strongest biomolecular system known, streptavidin (SAv)-biotin. The bound SAv and the linkers can be selectively removed from the surface through competitive desorption with concentrated ?-CD, regenerating the sensor for repeated use. An added advantage of ?-CD is the possibility of stereoselective sensors, and we demonstrate here the ability to quantify the enantiomeric composition of chiral targets. PMID:23566420

Duan, Xuexin; Rajan, Nitin K.; Routenberg, David A.; Huskens, Jurriaan

2013-01-01

94

High-energy regenerative thin disk amplifier  

NASA Astrophysics Data System (ADS)

Design of a compact regenerative laser amplifier based on two Yb:YAG thin-disks is presented. Energy up to 100 mJ in picoseconds pulses will be delivered with a repetition rate of 1 kHz. System is designed for seeding a kW-class multipass amplifier for industrial and scientific applications. Laser heads are pumped at zero-phonon line (968.825 nm [1]) by stabilized high-power pump diodes operated in pulsed regime. Seed pulses are produced in a fiber oscillator at 1030 nm and CPA technique utilizing transmission gratings for pulse stretching and compression is applied.

Chyla, Michal; Smrz, Martin; Mocek, Tomas

2012-07-01

95

Bioprinting is changing regenerative medicine forever.  

PubMed

3D printing, or solid freeform fabrication, applied to regenerative medicine brings technologies from several industries together to help solve unique challenges in both basic science and tissue engineering. By more finely organizing cells and supporting structures precisely in 3D space, we will gain critical knowledge of cell-cell communications and cell-environment interactions. As we increase the scale, we will move toward complex tissue and organ structures where several cell phenotypes will functionally and structurally interact, thus recapitulating the form and function of native tissues and organs. PMID:25457969

Collins, Scott Forrest

2014-12-01

96

Feasibility investigation of allogeneic endometrial regenerative cells  

PubMed Central

Endometrial Regenerative Cells (ERC) are a population of mesenchymal-like stem cells having pluripotent differentiation activity and ability to induce neoangiogenesis. In vitro and animal studies suggest ERC are immune privileged and in certain situations actively suppress ongoing immune responses. In this paper we describe the production of clinical grade ERC and initial safety experiences in 4 patients with multiple sclerosis treated intravenously and intrathecally. The case with the longest follow up, of more than one year, revealed no immunological reactions or treatment associated adverse effects. These preliminary data suggest feasibility of clinical ERC administration and support further studies with this novel stem cell type. PMID:19232091

Zhong, Zhaohui; Patel, Amit N; Ichim, Thomas E; Riordan, Neil H; Wang, Hao; Min, Wei-Ping; Woods, Erik J; Reid, Michael; Mansilla, Eduardo; Marin, Gustavo H; Drago, Hugo; Murphy, Michael P; Minev, Boris

2009-01-01

97

Small Molecule based Musculoskeletal Regenerative Engineering  

PubMed Central

Clinicians and scientists working in the field of regenerative engineering are actively investigating a wide range of methods to promote musculoskeletal tissue regeneration. Small molecule-mediated tissue regeneration is emerging as a promising strategy for regenerating various musculoskeletal tissues and a large number of small molecule compounds have been recently discovered as potential bioactive molecules for musculoskeletal tissue repair and regeneration. In this review, we summarize the recent literature encompassing the past four years in the area of small bioactive molecule for promoting repair and regeneration of various musculoskeletal tissues including bone, muscle, cartilage, tendon, and nerve. PMID:24405851

Lo, Kevin W.-H.; Jiang, Tao; Gagnon, Keith A.; Nelson, Clarke; Laurencin, Cato T.

2014-01-01

98

Feasibility investigation of allogeneic endometrial regenerative cells.  

PubMed

Endometrial Regenerative Cells (ERC) are a population of mesenchymal-like stem cells having pluripotent differentiation activity and ability to induce neoangiogenesis. In vitro and animal studies suggest ERC are immune privileged and in certain situations actively suppress ongoing immune responses. In this paper we describe the production of clinical grade ERC and initial safety experiences in 4 patients with multiple sclerosis treated intravenously and intrathecally. The case with the longest follow up, of more than one year, revealed no immunological reactions or treatment associated adverse effects. These preliminary data suggest feasibility of clinical ERC administration and support further studies with this novel stem cell type. PMID:19232091

Zhong, Zhaohui; Patel, Amit N; Ichim, Thomas E; Riordan, Neil H; Wang, Hao; Min, Wei-Ping; Woods, Erik J; Reid, Michael; Mansilla, Eduardo; Marin, Gustavo H; Drago, Hugo; Murphy, Michael P; Minev, Boris

2009-01-01

99

Brunner's Gland Hyperplasia: Treatment of Severe Diffuse Nodular Hyperplasia Mimicking a Malignancy on Pancreatic-Duodenal Area  

PubMed Central

Brunner's gland hyperplasia is a benign tumor of the duodenum and it is rarely associated with clinical symptoms. We report on a 64-yr-old man with Brunner's gland hyperplasia who had undergone a duodenocephalo-pancreatectomy. The reason is that he presented upper gastrointestinal obstructive symptoms and the esophagogastroduodenoscopic finding revealed the lesion to be an infiltrating type mass on the second portion of the duodenum with luminal narrowing. An abdominal computed tomography showed a 2.5 cm-sized mass in the duodenal second portion with a suspicious pancreatic invasion and 7 mm-sized lymph node around the duodenum. Duodenocephalopancreatectomy was successfully performed. Histological examination revealed a Brunner's gland hyperplasia. The final diagnosis was the coexistence of Brunner's gland hyperplasia and pancreatic heterotopia with a pancreatic head invasion. The literature on Brunner's gland hyperplasia is reviewed. PMID:18583897

Lee, Woong Chul; Lee, Yun Jung; Jung, Sung Hee; Choi, Gi Young; Go, Hoon; Kim, Anna; Cha, Sang Woo

2008-01-01

100

78 FR 43889 - Synergizing Efforts in Standards Development for Cellular Therapies and Regenerative Medicine...  

Federal Register 2010, 2011, 2012, 2013, 2014

...for Cellular Therapies and Regenerative Medicine Products; Public Workshop AGENCY: Food...for Cellular Therapies and Regenerative Medicine Products.'' The purpose of the public...involving cellular therapies and regenerative medicine products. Date and Time: The...

2013-07-22

101

Multiple excitation regenerative amplifier inertial confinement system  

DOEpatents

The invention relates to apparatus and methods for producing high intensity laser radiation generation which is achieved through an optical amplifier-storage ring design. One or two synchronized, counterpropagating laser pulses are injected into a regenerative amplifier cavity and amplified by gain media which are pumped repetitively by electrical or optical means. The gain media excitation pulses are tailored to efficiently amplify the laser pulses during each transit. After the laser pulses have been amplified to the desired intensity level, they are either switched out of the cavity by some switch means, as for example an electro-optical device, for any well known laser end uses, or a target means may be injected into the regenerative amplifier cavity in such a way as to intercept simultaneously the counterpropagating laser pulses. One such well known end uses to which this invention is intended is for production of high density and temperature plasmas suitable for generating neutrons, ions and x-rays and for studying matter heated by high intensity laser radiation.

George, Victor E. [Livermore, CA; Haas, Roger A. [Pleasanton, CA; Krupke, William F. [Pleasanton, CA; Schlitt, Leland G. [Livermore, CA

1980-05-27

102

Integrated regenerative fuel cell experimental evaluation  

NASA Astrophysics Data System (ADS)

An experimental test program was conducted to investigate the performance characteristics of an integrated regenerative fuel cell (IRFC) concept. The IRFC consists of a separate fuel cell unit and electrolysis cell unit in the same structure, with internal storage of fuel cell product water and external storage of electrolysis cell produced hydrogen and oxygen. The fuel cell unit incorporates an enhanced Orbiter-type cell capable of improved performance at reduced weight. The electrolysis cell features a NiCo2O4 catalyst oxygen evolution eletrode with a porous Teflon cover to retard electrolyte loss. Six complete IRFC assemblies were assembled and performance tested at an operating temperature of 200 F (93.3 C) and reactant pressures up to 170 psia (117.2 n/cu cm) on IRFC No. 4. Anomalous pressure charge/discharge characteristics were encountered during performance evaluation. A reversible fuel cell incorporating a proprietary bi-functional oxygen electrode operated satisfactory at 200 F (93.3 C) at reactant pressures up to 50 psia (41.4 n/cu cm) as a regenerative fuel cell for one cycle, before developing an electrical short in the fuel cell mode. Electrolysis cell 300-hour endurance tests demonstrated the electrolyte retention capability of the electrode Teflon cover and the performance stability of the bi-functional oxygen electrode at high potential.

Martin, Ronald E.

1990-01-01

103

Multiple excitation regenerative amplifier inertial confinement system  

DOEpatents

The invention relates to apparatus and methods for producing high intensity laser radiation generation which is achieved through an optical amplifier-storage ring design. One or two synchronized, counterpropagating laser pulses are injected into a regenerative amplifier cavity and amplified by gain media which are pumped repetitively by electrical or optical means. The gain media excitation pulses are tailored to efficiently amplify the laser pulses during each transit. After the laser pulses have been amplified to the desired intensity level, they are either switched out of the cavity by some switch means, as for example an electro-optical device, for any well known laser end uses, or a target means may be injected into the regenerative amplifier cavity in such a way as to intercept simultaneously the counterpropagating laser pulses. One such well known end uses to which this invention is intended is for production of high density and temperature plasmas suitable for generating neutrons, ions and x-rays and for studying matter heated by high intensity laser radiation. 11 figs.

George, V.E.; Haas, R.A.; Krupke, W.F.; Schlitt, L.G.

1980-05-27

104

Erich Regener - a forgotten cosmic ray pioneer  

NASA Astrophysics Data System (ADS)

In the 1930s the German physicist Erich Regener (1881-1955), did important work on the measurement of the rate production of ionisation in the atmosphere and deep under-water. He discovered, along with one of his students, Georg Pfotzer, the altitude at which the production of ionisation in the atmosphere reaches a maximum, often and misleadingly called the Pfotzer maximum. He was one of the first to estimate the energy density of cosmic rays, an estimate used by Baade and Zwicky to postulate that supernovae might be the source of cosmic rays. Yet Regener's name is little known largely because he was forced to take early retirement by the National Socialists in 1937 as his wife had Jewish ancestors. In this paper we review his work on cosmic rays and the subsequent influence that he had on the subject through his son, his son-in-law, his grandson and his students. He was nominated for the Nobel Prize in Physics by Schroedinger in 1938. He died in 1955 at the age of 73.

Carlson, Per; Watson, Alan

2013-04-01

105

DESIGNING HUMAN 2.0 (TRANSHUMAN) – REGENERATIVE EXISTENCE  

Microsoft Academic Search

This paper explores regenerative existence for Human 2.0 – the transhuman. In building this focus, the author addresses the use of emerging technologies as propitious in designing the amended, extended, and suspended human body. Here, a first focus covers emerging biotechnologies for regenerative existence, which play a large role in extreme life extension. A second focus covers the digital technologies

Natasha Vita-More

2008-01-01

106

Stem Cells: Intellectual Property Issues in Regenerative Medicine  

PubMed Central

Abstract The topic of stem cells for use in regenerative medicine, especially embryonic stem cells, inspires much debate, discussion, and outrage as it slices through the very core moral values of society. These social and moral issues have, in turn, resulted in government policies that have influenced the study of stem cells in regenerative medicine. PMID:24304078

Zachariades, Nicholas A.

2013-01-01

107

Regenerative thermal storage in atmospheric air system solar power plants  

Microsoft Academic Search

In a regenerative thermal storage system, thermal energy is transferred from a hot working fluid to the storage unit core elements during charging, and from the core elements to the cold working fluid during discharging. Regenerative thermal storage systems are used in many traditional applications, e.g. in steelmaking processes.Supply of solar energy is uncontrollable due to cloud passages. The projected

H. W. Fricker

2004-01-01

108

2013-2014 Handbook Stem Cell Biology and Regenerative  

E-print Network

. The SCBRM program is housed within the Lorry Lokey Stem Cell Research Building, a modern research facility2013-2014 Handbook Stem Cell Biology and Regenerative Medicine Interdisciplinary Graduate Program (PhD) #12;Institute for Stem Cell Biology and Regenerative Medicine Interdisciplinary Graduate Program

Puglisi, Joseph

109

State of the art: Stem cells in equine regenerative medicine.  

PubMed

According to Greek mythology, Prometheus' liver grew back nightly after it was removed each day by an eagle as punishment for giving mankind fire. Hence, contrary to popular belief, the concept of tissue and organ regeneration is not new. In the early 20th century, cell culture and ex vivo organ preservation studies by Alexis Carrel, some with famed aviator Charles Lindbergh, established a foundation for much of modern regenerative medicine. While early beliefs and discoveries foreshadowed significant accomplishments in regenerative medicine, advances in knowledge within numerous scientific disciplines, as well as nano- and micromolecular level imaging and detection technologies, have contributed to explosive advances over the last 20 years. Virtually limitless preparations, combinations and applications of the 3 major components of regenerative medicine, namely cells, biomaterials and bioactive molecules, have created a new paradigm of future therapeutic options for most species. It is increasingly clear, however, that despite significant parallels among and within species, there is no 'one-size-fits-all' regenerative therapy. Likewise, a panacea has yet to be discovered that completely reverses the consequences of time, trauma and disease. Nonetheless, there is no question that the promise and potential of regenerative medicine have forever altered medical practices. The horse is a relative newcomer to regenerative medicine applications, yet there is already a large body of work to incorporate novel regenerative therapies into standard care. This review focuses on the current state and potential future of stem cells in equine regenerative medicine. PMID:24957845

Lopez, M J; Jarazo, J

2015-03-01

110

Physiological Regeneration of Skin Appendages and Implications for Regenerative Medicine  

NSDL National Science Digital Library

The concept of regenerative medicine is relatively new, but animals are well known to remake their hair and feathers regularly by normal regenerative physiological processes. Here, we focus on 1) how extrafollicular environments can regulate hair and feather stem cell activities and 2) how different configurations of stem cells can shape organ forms in different body regions to fulfill changing physiological needs.

Cheng-Ming Chuong (University of Southern California, School of Medicine); Valerie Randall (University of Bradford); Randall Widelitz (University of Southern California, School of Medicine); Ping Wu (University of Southern California, School of Medicine); Ting-Xin Jiang (University of Southern California, School of Medicine)

2012-04-01

111

Advances in understanding tissue regenerative capacity and mechanisms in animals  

Microsoft Academic Search

Questions about how and why tissue regeneration occurs have captured the attention of countless biologists, biomedical engineers and clinicians. Regenerative capacity differs greatly across organs and organisms, and a range of model systems that use different regenerative strategies and that offer different technical advantages have been studied to understand regeneration. Making use of this range of systems and approaches, recent

Kenneth D. Poss

2010-01-01

112

Evaluation strategy of regenerative braking energy for supercapacitor vehicle.  

PubMed

In order to improve the efficiency of energy conversion and increase the driving range of electric vehicles, the regenerative energy captured during braking process is stored in the energy storage devices and then will be re-used. Due to the high power density of supercapacitors, they are employed to withstand high current in the short time and essentially capture more regenerative energy. The measuring methods for regenerative energy should be investigated to estimate the energy conversion efficiency and performance of electric vehicles. Based on the analysis of the regenerative braking energy system of a supercapacitor vehicle, an evaluation system for energy recovery in the braking process is established using USB portable data-acquisition devices. Experiments under various braking conditions are carried out. The results verify the higher efficiency of energy regeneration system using supercapacitors and the effectiveness of the proposed measurement method. It is also demonstrated that the maximum regenerative energy conversion efficiency can reach to 88%. PMID:25311161

Zou, Zhongyue; Cao, Junyi; Cao, Binggang; Chen, Wen

2014-10-10

113

Phytotherapy of benign prostatic hyperplasia. A minireview.  

PubMed

Benign prostate hyperplasia (BPH) is a common condition affecting older men, with an incidence that is age-dependent. Histological BPH, which typically develops after the age of 40 years, ranges in prevalence from >50% at 60 years to as high as 90% by 85 years of age. Typical symptoms include increased frequency of urination, nocturia, urgency, hesitancy, and weak urine stream. Conventional medicines used for the treatment of BPH include alpha blockers and 5-alpha reductase inhibitors. This articles review the mode of action, the efficacy, and the safety, including herb-drug interactions of the most common botanicals (Serenoa repens, Pygeum africanum, Urtica dioica, and Cucurbita pepo) and nutraceuticals (isoflavones, lycopene, selenium, and ?-Sitosterol) in controlling the lower urinary tract symptoms associated to BPH. PMID:25165780

Pagano, Ester; Laudato, Massimiliano; Griffo, Michele; Capasso, Raffaele

2014-07-01

114

Microwave Treatment of Prostate Cancer and Hyperplasia  

NASA Technical Reports Server (NTRS)

Microwave ablation in the form of microwave energy applied to a heart muscle by a coaxial catheter inserted in a vein in the groin area can be used to heat and kill diseased heart cells. A microwave catheter has been developed to provide deep myocardial ablation to treat ventricular tachycardia by restoring appropriate electrical activity within the heart and eliminating irregular heartbeats. The resulting microwave catheter design, which is now being developed for commercial use in treating ventricular tachycardia, can be modified to treat prostate cancer and benign prostatic hyperplasia (BPH). Inasmuch as the occurrence of BPH is increasing currently 350,000 operations per year are performed in the United States alone to treat this condition this microwave catheter has significant commercial potential.

Arndt, G. Dickey; Ngo, Phong; Carl, J. R.; Raffoul, George

2005-01-01

115

Rete testis adenomatous hyperplasia: our experience.  

PubMed

The word "adenomatous hyperplasia of rete testis" (AHRT) was used by M. Nistal et Al. for the first time in an article about the cystic dysplasia of the testis (1976). AHRT is a benign lesion of the testis. The patient who came to our attention was studied with a testicular echo color Doppler that identified a solid, well circumscribed and hypoechoic mass of 4.5 x3.8mm as diameter, localized in the upper third of the right testicle and with a perilesional vascularization pattern. The preoperative study was based on an accurate medical history, on an ultrasound with contrast and on a RMI. The treatment consisted in an echo guided excisional biopsy of the testicular lesion, considering this as the best approach for those testicular neoformation difficult to define, with a lot of benefits for the patients, especially for those monorchid. PMID:24311150

Martino, Giovanni; Pasta, Vittorio; Ciardi, Antonio; Palmieri, Andrea; Marinaccio, Lucia; Malavenda, Maria Stella; Monti, Massimo

2013-01-01

116

Evaluating Men with Benign Prostatic Hyperplasia  

PubMed Central

The clinical manifestations of benign prostatic hyperplasia (BPH) include lower urinary tract symptoms (LUTS), poor bladder emptying, urinary retention, detrusor instability, urinary tract infection, hematuria, and renal insufficiency. However, the majority of men with BPH present with LUTS only. Because LUTS can indicate a variety of conditions, evaluation of symptomatic men must first aim to identify or exclude BPH and, if present, assess its severity. It is important to assess symptom severity at baseline and during follow-up, using the American Urological Association Symptom Index or the International Prostate Symptom Score. Further testing can then be tailored to narrow the diagnosis and guide treatment decisions. Factors such as patient age and concomitant malignancy will also affect management, but the main goal of treatment remains the improvement of quality of life for the patient. PMID:16985855

Lepor, Herbert

2004-01-01

117

Solar Airplanes and Regenerative Fuel Cells  

NASA Technical Reports Server (NTRS)

A solar electric aircraft with the potential to "fly forever" has captured NASA's interest, and the concept for such an aircraft was pursued under Aeronautics Environmental Research Aircraft and Sensor Technology (ERAST) project. Feasibility of this aircraft happens to depend on the successful development of solar power technologies critical to NASA's Exploration Initiatives; hence, there was widespread interest throughout NASA to bring these technologies to a flight demonstration. The most critical is an energy storage system to sustain mission power during night periods. For the solar airplane, whose flight capability is already limited by the diffuse nature of solar flux and subject to latitude and time of year constraints, the feasibility of long endurance flight depends on a storage density figure of merit better than 400-600 watt-hr per kilogram. This figure of merit is beyond the capability of present day storage technologies (other than nuclear) but may be achievable in the hydrogen-oxygen regenerative fuel cell (RFC). This potential has led NASA to undertake the practical development of a hydrogen-oxygen regenerative fuel cell, initially as solar energy storage for a high altitude UAV science platform but eventually to serve as the primary power source for NASAs lunar base and other planet surface installations. Potentially the highest storage capacity and lowest weight of any non-nuclear device, a flight-weight RFC aboard a solar-electric aircraft that is flown continuously through several successive day-night cycles will provide the most convincing demonstration that this technology's widespread potential has been realized. In 1998 NASA began development of a closed cycle hydrogen oxygen PEM RFC under the Aeronautics Environmental Research Aircraft and Sensor Technology (ERAST) project and continued its development, originally for a solar electric airplane flight, through FY2005 under the Low Emissions Alternative Power (LEAP) project. Construction of the closed loop system began in 2002 at the NASA Glenn Research Center in Cleveland, Ohio. System checkout was completed, and testing began, in July of 2003. The initial test sequences were done with only a fuel cell or electrolyzer in the test rig. Those tests were used to verify the test apparatus, procedures, and software. The first complete cycles of the fully closed loop, regenerative fuel cell system were successfully completed in the following September. Following some hardware upgrades to increase reactant recirculation flow, the test rig was operated at full power in December 2003 and again in January 2004. In March 2004 a newer generation of fuel cell and electrolyzer stacks was substituted for the original hardware and these stacks were successfully tested at full power under cyclic operation in June of 2004.

Bents, David J.

2007-01-01

118

Regenerative system for a gas turbine  

SciTech Connect

A regenerative system is described for a gas turbine, wherein the turbine has a single shaft on which are mounted a compressor section and a work section, comprising: an air heater mounted adjacent the exit of the work section, the hot exit gas and pressurized air passing through passages formed in the air heater; combustor housings surrounding the compressor section, each containing a combustor mounted within it and extending coaxially thereof, each combustor having a transition section extending to the entrance to the work section; an annular connector housing extending between the combustor housing and the exit of the compressor section to carry the compressed air radially; an outer duct leading from the connector housing to one end of the air heater; and an inner duct attached to the other end of the air heater.

Wadsworth, W.

1987-04-28

119

Why regenerative medicine needs an extracellular matrix.  

PubMed

Regenerative medicine is now coming of age. Many attempts at cell therapy have failed to show significant efficacy, and the umbrella term 'stem cell therapy' is perceived in some quarters as hype or just expensive and unnecessary medical tourism. Here we present a short editorial in three parts. First, we examine the importance of using a semisynthetic extracellular matrix (ECM) mimetic, or sECM, to deliver and retain therapeutic cells at the site of administration. Second, we describe one approach in which biophysical and biochemical properties are tailored to each tissue type, which we call "design for optimal functionality." Third, we describe an alternative approach to sECM design and implementation, called "design for simplicity," in which a deconstructed, minimalist sECM is employed and biology is allowed to perform the customization in situ. We opine that an sECM, whether minimal or instructive, is an essential contributor to improve the outcomes of cell-based therapies. PMID:25482878

Prestwich, Glenn D; Healy, Kevin E

2015-01-01

120

Liposomes in tissue engineering and regenerative medicine  

PubMed Central

Liposomes are vesicular structures made of lipids that are formed in aqueous solutions. Structurally, they resemble the lipid membrane of living cells. Therefore, they have been widely investigated, since the 1960s, as models to study the cell membrane, and as carriers for protection and/or delivery of bioactive agents. They have been used in different areas of research including vaccines, imaging, applications in cosmetics and tissue engineering. Tissue engineering is defined as a strategy for promoting the regeneration of tissues for the human body. This strategy may involve the coordinated application of defined cell types with structured biomaterial scaffolds to produce living structures. To create a new tissue, based on this strategy, a controlled stimulation of cultured cells is needed, through a systematic combination of bioactive agents and mechanical signals. In this review, we highlight the potential role of liposomes as a platform for the sustained and local delivery of bioactive agents for tissue engineering and regenerative medicine approaches. PMID:25401172

Monteiro, Nelson; Martins, Albino; Reis, Rui L.; Neves, Nuno M.

2014-01-01

121

Power Management in Regenerative Life Support Systems  

NASA Technical Reports Server (NTRS)

Effective management of power can reduce the cost of launch and operation of regenerative life support systems. Variations in power may be quite severe and may manifest as surges or spikes, While the power plant may have some ability to deal with these variations, with batteries for example, over-capacity is expensive and does nothing to address the fundamental issue of excessive demand. Because the power unit must be sized to accommodate the largest demand, avoiding power spikes has the potential to reduce the required size of the power plant while at the same time increasing the dependability of the system. Scheduling of processors can help to reduce potential power spikes. However, not all power-consuming equipment is easily scheduled. Therefore, active power management is needed to further decrease the risk of surges or spikes. We investigate the use of a hierarchical scheme to actively manage power for a model of a regenerative life support system. Local level controllers individually determine subsystem power usage. A higher level controller monitors overall system power and detects surges or spikes. When a surge condition is detected, the higher level controller conducts an 'auction' and describes subsystem power usage to re-allocate power. The result is an overall reduction in total power during a power surge. The auction involves each subsystem making a 'bid' to buy or sell power based on local needs. However, this re-allocation cannot come at the expense of life support function. To this end, participation in the auction is restricted to those processes meeting certain tolerance constraints. These tolerances represent acceptable limits within which system processes can be operated. We present a simulation model and discuss some of our results.

Crawford, Sekou; Pawlowski, Christopher; Finn, Cory; Mead, Susan C. (Technical Monitor)

1999-01-01

122

Materials science tools for regenerative medicine  

NASA Astrophysics Data System (ADS)

Regenerative therapies originating from recent technological advances in biology could revolutionize medicine in the coming years. In particular, the advent of human pluripotent stem cells (hPSCs), with their ability to become any cell in the adult body, has opened the door to an entirely new way of treating disease. However, currently these medical breakthroughs remain only a promise. To make them a reality, new tools must be developed to surmount the new technical hurdles that have arisen from dramatic departure from convention that this field represents. The collected work presented in this dissertation covers several projects that seek to apply the skills and knowledge of materials science to this tool synthesizing effort. The work is divided into three chapters. The first deals with our work to apply Raman spectroscopy, a tool widely used for materials characterization, to degeneration in cartilage. We have shown that Raman can effectively distinguish the matrix material of healthy and diseased tissue. The second area of work covered is the development of a new confocal image analysis for studying hPSC colonies that are chemical confined to uniform growth regions. This tool has important application in understanding the heterogeneity that may slow the development of hPSC -based treatment, as well as the use of such confinement in the eventually large-scale manufacture of hPSCs for therapeutic use. Third, the use of structural templating in tissue engineering scaffolds is detailed. We have utilized templating to tailor scaffold structures for engineering of constructs mimicking two tissues: cartilage and lung. The work described here represents several important early steps towards large goals in regenerative medicine. These tools show a great deal of potential for accelerating progress in this field that seems on the cusp of helping a great many people with otherwise incurable disease.

Richardson, Wade Nicholas

123

The TMI Regenerative Solid Oxide Fuel Cell  

NASA Technical Reports Server (NTRS)

Energy storage and production in space requires rugged, reliable hardware which minimizes weight, volume, and maintenance while maximizing power output and usable energy storage. Systems generally consist of photovoltaic solar arrays which operate (during sunlight cycles) to provide system power and regenerate fuel (hydrogen) via water electrolysis and (during dark cycles) fuel cells convert hydrogen into electricity. Common configurations use two separate systems (fuel cell and electrolyzer) in conjunction with photovoltaic cells. Reliability, power to weight and power to volume ratios could be greatly improved if both power production (fuel cells) and power storage (electrolysis) functions can be integrated into a single unit. The solid oxide fuel cell (SOFC) based design integrates fuel cell and electrolyzer functions and potentially simplifies system requirements. The integrated fuel cell/electrolyzer design also utilizes innovative gas storage concepts and operates like a rechargeable 'hydrogen-oxygen battery'. Preliminary research has been completed on improved H2/H20 electrode (SOFC anode/electrolyzer cathode) materials for regenerative fuel cells. Tests have shown improved cell performance in both fuel and electrolysis modes in reversible fuel cell tests. Regenerative fuel cell efficiencies, ratio of power out (fuel cell mode) to power in (electrolyzer mode), improved from 50 percent using conventional electrode materials to over 80 percent. The new materials will allow a single SOFC system to operate as both the electolyzer and fuel cell. Preliminary system designs have also been developed to show the technical feasibility of using the design for space applications requiring high energy storage efficiencies and high specific energy. Small space systems also have potential for dual-use, terrestrial applications.

Cable, Thomas L.; Ruhl, Robert C.; Petrik, Michael

1996-01-01

124

Regenerative Blower for EVA Suit Ventilation Fan  

NASA Technical Reports Server (NTRS)

Portable life support systems in future space suits will include a ventilation subsystem driven by a dedicated fan. This ventilation fan must meet challenging requirements for pressure rise, flow rate, efficiency, size, safety, and reliability. This paper describes research and development that showed the feasibility of a regenerative blower that is uniquely suited to meet these requirements. We proved feasibility through component tests, blower tests, and design analysis. Based on the requirements for the Constellation Space Suit ventilation fan, we designed the critical elements of the blower. We measured the effects of key design parameters on blower performance using separate effects tests, and used the results of these tests to design a regenerative blower that will meet the ventilation fan requirements. We assembled a proof-of-concept blower and measured its performance at low pressures that simulate a PLSS environment. We obtained head/flow performance curves over a range of operating speeds, identified the maximum efficiency point for the blower, and used these results to specify the design and operating conditions for the ventilation fan. We designed a compact motor that can drive the blower under all anticipated operating requirements and operate with high efficiency during normal operation. We identified materials for the blower that will enhance safety for operation in a lunar environment. We produced a solid model that illustrates the final design. The proof-of-concept blower produced the flow rate and pressure rise needed for the CSSS ventilation subsystem while running at 5400 rpm and consuming only 9 W of electric power and using a non-optimized, commercial motor and controller and inefficient bearings. Scaling the test results to a complete design shows that a lightweight, compact, reliable, and low power blower can meet the performance requirements for future PLSSs.

Paul, Heather; Izenson, Mike; Chen, Weibo

2008-01-01

125

MX-INDUCED URINARY BLADDER EPITHELIAL HYPERPLASIA IN EKER RATS  

EPA Science Inventory

MX-INDUCED URINARY BLADDER EPITHELIAL HYPERPLASIA IN EKER RATS Epidemiological studies have shown a positive association between chronic exposure to chlorinated drinking water and human cancer, particularly of the urinary bladder. MX (3- chloro-4-(dichloromethyl)-5-hydrox...

126

Augmentation of postresection mucosal hyperplasia by plerocercoid growth factor (PGF)  

Microsoft Academic Search

Postresection villus hyperplasia is a major compensatory mechanism in the short-bowel patient. Substances capable of augmenting postresection mucosal hyperplasia could have therapeutic implications. Human growth hormone (hGH) and human growth hormone releasing factor (hGHRF) stimulate growth of the gastrointestinal tract; however, the diabetogenic actions of growth hormone limit its usefulness in clinical practice. Plerocercoid larvae of the tapewormSpirometra mansonoides produce

Michael H. Hart; C. K. Phares; Steven H. Erdman; Carter J. Grandjean; Jung H. Y. Park; Jon A. Vanderhoof

1987-01-01

127

Regenerative PN ranging experience with New Horizons during 2012  

NASA Astrophysics Data System (ADS)

The New Horizons mission to Pluto is the first deep space mission to include the capability of supporting regenerative PN ranging. During the current phase of the mission, sequential tone ranging supports the mission navigation requirements but regenerative ranging will expand the conditions (antenna selection, integration time, etc.) over which ranging will be successful during any extended mission following the Pluto fly-by, to objects in the Kuiper belt. Experience with regenerative ranging is being obtained now in preparation for its use in an extended mission. During most of 2012, New Horizons was in a hibernation state. Tracking was conducted between late April and early July. Six regenerative ranging passes were performed to bookend this interval; 2 at the beginning and 4 at the end. During that time, the distance between the spacecraft and Earth was in excess of 22 Astronautical Units (AU) and the Pr/No levels were below 15 dB-Hz. A seventh regenerative ranging pass was performed in May at a higher signal level in order to test the acquisition of the ranging code by the spacecraft during a variety of conditions. The consistency of the regenerative range measurements with the adjacent sequential tone ranging measurements has been demonstrated and serves as a check on the calibration of the regenerative ranging system conditions. The range measurement precision has been shown to follow the predictions that are based on the uplink and downlink signal power. The regenerative ranging system has been shown to acquire the uplink ranging code with and without a commanded reset and regardless of the noise bandwidth setting of the system. This paper will present the data that was obtained during 2012 and will describe the analysis results for the regenerative ranging experience during 2012.

Jensen, J. R.; Haskins, C. B.; DeBoy, C. C.

128

Adaptive controller for regenerative and friction braking system  

DOEpatents

A regenerative and friction braking system for a vehicle having one or more roadwheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the roadwheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the roadwheels of the vehicle without skidding or slipping will not be exceeded.

Davis, Roy I. (Ypsilanti, MI)

1990-01-01

129

Adaptive controller for regenerative and friction braking system  

DOEpatents

A regenerative and friction braking system for a vehicle having one or more road wheels driven by an electric traction motor includes a driver responsive device for producing a brake demand signal having a magnitude corresponding to the level of braking force selected by the driver and friction and regenerative brakes operatively connected with the road wheels of the vehicle. A system according to this invention further includes control means for operating the friction and regenerative braking subsystems so that maximum brake torques sustainable by the road wheels of the vehicle without skidding or slipping will not be exceeded. 8 figs.

Davis, R.I.

1990-10-16

130

Regenerative endodontics: barriers and strategies for clinical translation.  

PubMed

Regenerative endodontics has encountered substantial challenges toward clinical translation. The adoption by the American Dental Association of evoked pulp bleeding in immature permanent teeth is an important step for regenerative endodontics. However, there is no regenerative therapy for most endodontic diseases. Simple recapitulation of cell therapy and tissue engineering strategies that are under development for other organ systems has not led to clinical translation in regeneration endodontics. Recent work using novel biomaterial scaffolds and growth factors that orchestrate the homing of host endogenous cells represents a departure from traditional cell transplantation approaches and may accelerate clinical translation. PMID:22835543

Mao, Jeremy J; Kim, Sahng G; Zhou, Jian; Ye, Ling; Cho, Shoko; Suzuki, Takahiro; Fu, Susan Y; Yang, Rujing; Zhou, Xuedong

2012-07-01

131

Cinacalcet HCl prevents development of parathyroid gland hyperplasia and reverses established parathyroid gland hyperplasia in a rodent model of CKD  

PubMed Central

Background. Secondary hyperparathyroidism (sHPT) represents an adaptive response to progressively impaired control of calcium, phosphorus and vitamin D in chronic kidney disease (CKD). It is characterized by parathyroid hyperplasia and excessive synthesis and secretion of parathyroid hormone (PTH). Parathyroid hyperplasia in uremic rats can be prevented by calcium-sensing receptor (CaSR) activation with the calcimimetic cinacalcet (Sensipar®/Mimpara®); however, it is unknown, how long the effects of cinacalcet persist after withdrawal of treatment or if cinacalcet is efficacious in uremic rats with established sHPT. Methods. We sought to determine the effect of cinacalcet discontinuation in uremic rats and whether cinacalcet was capable of influencing parathyroid hyperplasia in animals with established sHPT. Results. Discontinuation of cinacalcet resulted in reversal of the beneficial effects on serum PTH and parathyroid hyperplasia. In rats with established sHPT, cinacalcet decreased serum PTH and mediated regression of parathyroid hyperplasia. The cinacalcet-mediated decrease in parathyroid gland size was accompanied by increased expression of the cyclin-dependent kinase inhibitor p21. Prevention of cellular proliferation with cinacalcet occurred despite increased serum phosphorus and decreased serum calcium. Conclusions. The animal data provided suggest established parathyroid hyperplasia can be reversed by modulating CaSR activity with cinacalcet and that continued treatment may be necessary to maintain reductions in PTH. PMID:22036941

Miller, Gerald; Davis, James; Shatzen, Edward; Colloton, Matthew; Martin, David

2012-01-01

132

Hyperplasia and carcinoma in secretory endometrium: a diagnostic challenge.  

PubMed

The diagnosis of endometrial hyperplasia or carcinoma in a background of secretory endometrium can be difficult. We attempt to establish the diagnostic criteria to be used in such cases. We examined 80 cases of endometrial hyperplasia, carcinoma, and other conditions with glandular crowding arising in secretory endometrium, analyzed their morphologic features, assessed the volume percentage stroma in each case and performed Ki67 immunostaining on 27 cases. Thirteen cases each of secretory and gestational endometrium served as controls. The mean age of the patients was 45 yr. The non-neoplastic diseases included simple hyperplasia without atypia (56%), endometrial polyps (12.5%), and chronic endometritis with glandular crowding (3%). The proportion of cases with complex hyperplasia without atypia was 10%. Neoplastic diseases included atypical complex hyperplasia (12.5%) and endometrioid carcinoma (6%). The secretory changes were usually less advanced in the hyperplastic glands than in the background endometrium. The morphologic features that best distinguished hyperplasia or carcinoma from secretory endometrium included glandular crowding that stood out from the background; architectural disorder (the long axes of the glands pointing in different directions or parallel to the endometrial surface); dilated, irregularly shaped glands, including budding or branching glands and staghorn-shaped glands; stroma of a polyp; cribriform or confluent glands in cases of carcinoma; nuclear atypia in cases of atypical hyperplasia and carcinoma; and crowded nonsecretory glands. The volume percentage stroma of neoplastic lesions was less than that of non-neoplastic ones (34% vs. 61%, P=0.000001) and that of secretory endometrium (34% vs. 68%, P=0.000038). Non-neoplastic lesions did not have significantly more crowded glands than secretory endometrium (61% vs. 68%, P=0.11). Gestational endometrium had more crowded glands than non-neoplastic lesions (39% vs. 61%, P=0.000004), an approximately equal volume percentage stroma with complex hyperplasia without atypia (39% vs. 43%, P=0.51), and less crowded glands than neoplastic lesions (39% vs. 34%, P=0.03). The Ki67 index of the neoplastic lesions was higher than that of the controls, including secretory and gestational endometria (positive nuclei per 100 epithelial cells, 44.8 vs. 4.6, P=0.0004), of the non-neoplastic lesions (44.8 vs. 5.4, P=0.002) and of complex hyperplasia without atypia (44.8 vs. 9.3, P=0.007). Hyperplasia and carcinoma in secretory endometrium can be diagnosed on the basis of increased glandular crowding, architectural irregularity, nuclear atypia, and increased Ki67 index. PMID:24487463

Truskinovsky, Alexander M; Lifschitz-Mercer, Beatriz; Czernobilsky, Bernard

2014-03-01

133

Congenital adrenal hyperplasia: an update in children  

PubMed Central

Purpose of review Congenital adrenal hyperplasia (CAH) in children, the majority of which is due to 21-hydroxylase deficiency, represents a group of disorders in which there is impaired cortisol synthesis and abnormalities in adrenal hormonal profiles. There continues to be debate regarding the optimal management of and treatment for these children. This review will highlight the most recent advances in neonatal screening for CAH, as well as the timeliest recommendations for the treatment and management of 21-hydroxylase deficiency, both the classic and non-classic forms of the disorder. Recent findings Substantive advancements have been made with regards to neonatal screening for CAH, allowing for earlier diagnosis while minimizing the morbidity and mortality associated with delayed detection. While the achievement of normal growth and development remains the ultimate goal of treatment, recent studies have provided further insight into the management and refinement of therapy in these children. Summary The optimal management and treatment for children with CAH is still unclear. While there have been recent advances in the diagnosis and treatment of this group of disorders, there is still much to learn in order to optimize therapy for these individuals. PMID:21494138

Trapp, Christine M.; Speiser, Phyllis W.; Oberfield, Sharon E.

2013-01-01

134

Neointimal hyperplasia associated with synthetic hemodialysis grafts  

PubMed Central

Stenosis is a major cause of failure of hemodialysis vascular grafts and is primarily caused by neointimal hyperplasia (NH) at the anastomoses. The objective of this article is to provide a scientific review of the biology underlying this disorder and a critical review of the state-of-the-art investigational preventive strategies in order to stimulate further research in this exciting area. The histology of the NH shows myofibroblasts (that are probably derived from adventitial fibroblasts), extracellular matrices, pro-inflammatory cells including foreign-body giant cells, a variety of growth factors and cytokines, and neovasculature. The contributing factors of the pathogenesis of NH include surgical trauma, bioincompatibility of the synthetic graft, and the various mechanical stresses that result from luminal hypertension and compliance mismatch between the vessel wall and graft. These mechanical stimuli are focal in nature and may have a significant influence on the preferential localization of the NH. Novel mechanical graft designs and local drug delivery strategies show promise in animal models in preventing graft NH development. Successful prevention of graft stenosis would provide a superior alternative to the native fistula as hemodialysis vascular access. PMID:18668026

Li, Li; Terry, Christi M.; Shiu, Yan-Ting E.; Cheung, Alfred K.

2008-01-01

135

The mission of the UW Stem Cell and Regenerative Medi-  

E-print Network

the science of stem cell biology and foster breakthroughs in regenerative medicine through faculty to read, you need to read this newsletter to learn about the SCRMC activities, research breakthroughs

136

Regenerative fuel cell combines high efficiency with low cost  

NASA Technical Reports Server (NTRS)

Hydrogen/oxygen regenerative fuel cell stores electrical energy efficiently and inexpensively. The fuel cell has a high energy-to-weight ratio, and is adapted for a large number of cycles with deep discharge.

Doyle, H.; Frank, H.; Stephens, C. W.

1965-01-01

137

New Regenerative Cycle for Vapor Compression Refrigeration  

SciTech Connect

The main objective of this project is to confirm on a well-instrumented prototype the theoretically derived claims of higher efficiency and coefficient of performance for geothermal heat pumps based on a new regenerative thermodynamic cycle as comparing to existing technology. In order to demonstrate the improved performance of the prototype, it will be compared to published parameters of commercially available geothermal heat pumps manufactured by US and foreign companies. Other objectives are to optimize the design parameters and to determine the economic viability of the new technology. Background (as stated in the proposal): The proposed technology closely relates to EERE mission by improving energy efficiency, bringing clean, reliable and affordable heating and cooling to the residential and commercial buildings and reducing greenhouse gases emission. It can provide the same amount of heating and cooling with considerably less use of electrical energy and consequently has a potential of reducing our nations dependence on foreign oil. The theoretical basis for the proposed thermodynamic cycle was previously developed and was originally called a dynamic equilibrium method. This theory considers the dynamic equations of state of the working fluid and proposes the methods for modification of T-S trajectories of adiabatic transformation by changing dynamic properties of gas, such as flow rate, speed and acceleration. The substance of this proposal is a thermodynamic cycle characterized by the regenerative use of the potential energy of two-phase flow expansion, which in traditional systems is lost in expansion valves. The essential new features of the process are: (1) The application of two-step throttling of the working fluid and two-step compression of its vapor phase. (2) Use of a compressor as the initial step compression and a jet device as a second step, where throttling and compression are combined. (3) Controlled ratio of a working fluid at the first and second step of compression. In the proposed system, the compressor compresses the vapor only to 50-60% of the final pressure, while the additional compression is provided by a jet device using internal potential energy of the working fluid flow. Therefore, the amount of mechanical energy required by a compressor is significantly reduced, resulting in the increase of efficiency (either COP or EER). The novelty of the cycle is in the equipment and in the way the multi-staging is accomplished. The anticipated result will be a new refrigeration system that requires less energy to accomplish a cooling task. The application of this technology will be for more efficient designs of: (1) Industrial chillers, (2) Refrigeration plants, (3) Heat pumps, (4) Gas Liquefaction plants, (5) Cryogenic systems.

Mark J. Bergander

2005-08-29

138

An examination of regenerative organic Rankine cycles using dry fluids  

Microsoft Academic Search

This paper presents an analysis of regenerative organic Rankine cycles “ORC” using dry organic fluids, to convert waste energy to power from low-grade heat sources. The dry organic working fluids selected for this investigation are R113, R245ca, R123, and isobutane, with boiling points ranging from ?12°C to 48°C. Regenerative ORC is analyzed and compared with the basic ORC in order

Pedro J. Mago; Louay M. Chamra; Kalyan Srinivasan; Chandramohan Somayaji

2008-01-01

139

Optimal Design of Non-Regenerative MIMO Wireless Relays  

Microsoft Academic Search

Given a multiple-antenna source and a multiple-antenna destination, a multiple-antenna relay between the source and the destination is desirable under useful circumstances. A non-regenerative multiple-antenna relay, also called non-regenerative MIMO (multi-input multi-output) relay, is designed to optimize the capacity between the source and the destination. Without a direct link between the source and the destination, the optimal canonical coordinates of

Xiaojun Tang; Yingbo Hua

2007-01-01

140

From regenerative dentistry to regenerative medicine: progress, challenges, and potential applications of oral stem cells.  

PubMed

Adult mesenchymal stem cells (MSCs) and epithelial stem cells play essential roles in tissue repair and self-healing. Oral MSCs and epithelial stem cells can be isolated from adult human oral tissues, for example, teeth, periodontal ligament, and gingiva. Cocultivated adult oral epithelial stem cells and MSCs could represent some developmental events, such as epithelial invagination and tubular structure formation, signifying their potentials for tissue regeneration. Oral epithelial stem cells have been used in regenerative medicine over 1 decade. They are able to form a stratified cell sheet under three-dimensional culture conditions. Both experimental and clinical data indicate that the cell sheets can not only safely and effectively reconstruct the damaged cornea in humans, but also repair esophageal ulcer in animal models. Oral MSCs include dental pulp stem cells (DPSCs), stem cells from exfoliated deciduous teeth (SHED), stem cells from apical papilla (SCAP), periodontal ligament stem cells (PDLSCs), and mesenchymal stem cells from gingiva (GMSCs). They are widely applied in both regenerative dentistry and medicine. DPSCs, SHED, and SCAP are able to form dentin-pulp complex when being transplanted into immunodeficient animals. They have been experimentally used for the regeneration of dental pulp, neuron, bone muscle and blood vessels in animal models and have shown promising results. PDLSCs and GMSCs are demonstrated to be ideal cell sources for repairing the damaged tissues of periodontal, muscle, and tendon. Despite the abovementioned applications of oral stem cells, only a few human clinical trials are now underway to use them for the treatment of certain diseases. Since clinical use is the end goal, their true regenerative power and safety need to be further examined. PMID:25506228

Xiao, Li; Nasu, Masanori

2014-01-01

141

Manufacturing road map for tissue engineering and regenerative medicine technologies.  

PubMed

SummaryThe Regenerative Medicine Foundation Annual Conference held on May 6 and 7, 2014, had a vision of assisting with translating tissue engineering and regenerative medicine (TERM)-based technologies closer to the clinic. This vision was achieved by assembling leaders in the field to cover critical areas. Some of these critical areas included regulatory pathways for regenerative medicine therapies, strategic partnerships, coordination of resources, developing standards for the field, government support, priorities for industry, biobanking, and new technologies. The final day of this conference featured focused sessions on manufacturing, during which expert speakers were invited from industry, government, and academia. The speakers identified and accessed roadblocks plaguing the field where improvements in advanced manufacturing offered many solutions. The manufacturing sessions included (a) product development toward commercialization in regenerative medicine, (b) process challenges to scale up manufacturing in regenerative medicine, and (c) infrastructure needs for manufacturing in regenerative medicine. Subsequent to this, industry was invited to participate in a survey to further elucidate the challenges to translation and scale-up. This perspective article will cover the lessons learned from these manufacturing sessions and early results from the survey. We also outline a road map for developing the manufacturing infrastructure, resources, standards, capabilities, education, training, and workforce development to realize the promise of TERM. PMID:25575525

Hunsberger, Joshua; Harrysson, Ola; Shirwaiker, Rohan; Starly, Binil; Wysk, Richard; Cohen, Paul; Allickson, Julie; Yoo, James; Atala, Anthony

2015-02-01

142

Regenerative life support system research and concepts  

NASA Technical Reports Server (NTRS)

Life support systems that involve recycling of atmospheres, water, food and waste are so complex that models incorporating all the interactions and relationships are vital to design, development, simulations, and ultimately to control of space qualified systems. During early modeling studies, FORTRAN and BASIC programs were used to obtain numerical comparisons of the performance of different regenerative concepts. Recently, models were made by combining existing capabilities with expert systems to establish an Intelligent Design Support Environment for simpliflying user interfaces and to address the need for the engineering aspects. Progress was also made toward modeling and evaluating the operational aspects of closed loop life support systems using Time-step and Dynamic simulations over a period of time. Example models are presented which show the status and potential of developed modeling techniques. For instance, closed loop systems involving algae systeMs for atmospheric purification and food supply augmentation, plus models employing high plants and solid waste electrolysis are described and results of initial evaluations are presented.

1988-01-01

143

High power, high beam quality regenerative amplifier  

DOEpatents

A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

Hackel, Lloyd A. (Livermore, CA); Dane, Clifford B. (Livermore, CA)

1993-01-01

144

REGENERATIVE MEDICINE AS APPLIED TO GENERAL SURGERY  

PubMed Central

The present review illustrates the state of the art of regenerative medicine (RM) as applied to surgical diseases and demonstrates that this field has the potential to address some of the unmet needs in surgery. RM is a multidisciplinary field whose purpose is to regenerate in vivo or ex vivo human cells, tissues or organs in order to restore or establish normal function through exploitation of the potential to regenerate, which is intrinsic to human cells, tissues and organs. RM uses cells and/or specially designed biomaterials to reach its goals and RM-based therapies are already in use in several clinical trials in most fields of surgery. The main challenges for investigators are threefold: Creation of an appropriate microenvironment ex vivo that is able to sustain cell physiology and function in order to generate the desired cells or body parts; identification and appropriate manipulation of cells that have the potential to generate parenchymal, stromal and vascular components on demand, both in vivo and ex vivo; and production of smart materials that are able to drive cell fate. PMID:22330032

Orlando, Giuseppe; Wood, Kathryn J; De Coppi, Paolo; Baptista, Pedro M; Binder, Kyle W; Bitar, Khalil N; Breuer, Christopher; Burnett, Luke; Christ, George; Farney, Alan; Figliuzzi, Marina; Holmes, James H; Koch, Kenneth; Macchiarini, Paolo; Sani, Sayed-Hadi Mirmalek; Opara, Emmanuel; Remuzzi, Andrea; Rogers, Jeffrey; Saul, Justin M; Seliktar, Dror; Shapira-Schweitzer, Keren; Smith, Tom; Solomon, Daniel; Van Dyke, Mark; Yoo, James J; Zhang, Yuanyuan; Atala, Anthony; Stratta, Robert J; Soker, Shay

2012-01-01

145

New biomimetic directions in regenerative ophthalmology.  

PubMed

One of the most complete and permanent ways of treating many causes of visual impairment and blindness is to replace the entire affected tissue with pre-cultured ocular tissues supported and maintained on biomaterial frameworks. One direction towards enhancing ocular tissue regeneration on biomaterials, in the laboratory is by applying biomimicry. Specifically to engineer biomaterials with important functional elements of the native extracellular matrices, such as topography, that support and organise cells into coherent tissues. Further problems in regenerative ophthalmology can be potentially solved through application of biomimicry. They include, more efficient ways of moving and transplanting cultivated tissues into correct therapeutic locations inside the eye and scar-less, non-destructive healing of surgical incisions and wounds, to repair structural integrity of tissues at the ocular surface. Two examples are given to show this potential for redeveloping an ocular epithelium onto a nanostructured insect wing surface and producing an origami membrane modelled on deployable structures in nature. Efforts to harness natural innovation will eventually provide unique designs and structures that cannot for now be made synthetically, for regeneration of clinically acceptable ocular tissues. PMID:23184716

Green, David W; Watson, Gregory S; Watson, Jolanta; Abraham, Samuel J K

2012-03-01

146

Unitized Regenerative Fuel Cell System Development  

NASA Technical Reports Server (NTRS)

Unitized Regenerative Fuel Cells (URFC) have recently been developed by several fuel cell manufacturers. These manufacturers have concentrated their efforts on the development of the cell stack technology itself, and have not up to this point devoted much effort to the design and development of the balance of plant. A fuel cell technology program at the Glenn Research Center (GRC) that has as its goal the definition and feasibility testing of the URFC system balance of plant. Besides testing the feasibility, the program also intends to minimize the system weight, volume, and parasitic power as its goal. The design concept currently being developed uses no pumps to circulate coolant or reactants, and minimizes the ancillary components to only the oxygen and hydrogen gas storage tanks, a water storage tank, a loop heat pipe to control the temperature and two pressure control devices to control the cell stack pressures during operation. The information contained in this paper describes the design and operational concepts employed in this concept. The paper also describes the NASA Glenn research program to develop this concept and test its feasibility.

Burke, Kenneth A.

2003-01-01

147

Recent advances in acellular regenerative tissue scaffolds.  

PubMed

The management of chronic wounds is a considerable challenge for foot and ankle surgeons. The well-established tenets of adequate vascular supply, debridement with eradication of infection, and offloading must be employed in the management of all extremity wounds. Regenerative scaffolds are a viable means of reestablishing a favorable wound environment. The matrix facilitates cell migration, chemoattraction, angiogenesis, wound bed granulation, and expedited wound closure. Although studies have demonstrated success with acellular matrices, a multimodal approach should always be employed to improve healing success. Negative pressure wound therapy, compression, offloading, and antibiotics are advocated to improve outcomes. Acellular graft selection requires a multifactorial analysis, taking into consideration the specific patient and wound characteristics as well as the differences between acellular matrices. Patient age, comorbidities, activity level, and ability to comply with protocol as well as wound etiology, duration, depth, surface area, exudate, bacterial burden, location, vascular status, ischemic status, and presentation are all critical components. To effectively choose a matrix, the clinician must have a comprehensive understanding of the products available and the data validating their use. The mechanisms by which the acellular matrix accelerates wound healing and increases the likelihood of wound healing continue to be investigated. However, it is clear that these acellular biologic tissue scaffolds are incorporating into the host tissue, with resultant revascularization and cellular repopulation. Moving forward, additional investigations examining the effectiveness of acellular biologic tissue scaffolds to improve healing in complex, nondiabetic wounds are warranted. PMID:25440425

Protzman, Nicole M; Brigido, Stephen A

2015-01-01

148

High power, high beam quality regenerative amplifier  

DOEpatents

A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

Hackel, L.A.; Dane, C.B.

1993-08-24

149

Airway transplantation: a challenge for regenerative medicine  

PubMed Central

After more than 50 years of research, airway transplantation remains a major challenge in the fields of thoracic surgery and regenerative medicine. Five principal types of tracheobronchial substitutes, including synthetic prostheses, bioprostheses, allografts, autografts and bioengineered conduits have been evaluated experimentally in numerous studies. However, none of these works have provided a standardized technique for the replacement of the airways. More recently, few clinical attempts have offered encouraging results with ex vivo or stem cell–based engineered airways and tracheal allografts implanted after heterotopic revascularization. In 1997, we proposed a novel approach: the use of aortic grafts as a biological matrix for extensive airway reconstruction. In vivo regeneration of epithelium and cartilage were demonstrated in animal models. This led to the first human applications using cryopreserved aortic allografts that present key advantages because they are available in tissue banks and do not require immunosuppressive therapy. Favorable results obtained in pioneering cases have to be confirmed in larger series of patients with extensive tracheobronchial diseases. PMID:24059453

2013-01-01

150

Airway transplantation: a challenge for regenerative medicine.  

PubMed

After more than 50 years of research, airway transplantation remains a major challenge in the fields of thoracic surgery and regenerative medicine. Five principal types of tracheobronchial substitutes, including synthetic prostheses, bioprostheses, allografts, autografts and bioengineered conduits have been evaluated experimentally in numerous studies. However, none of these works have provided a standardized technique for the replacement of the airways. More recently, few clinical attempts have offered encouraging results with ex vivo or stem cell-based engineered airways and tracheal allografts implanted after heterotopic revascularization. In 1997, we proposed a novel approach: the use of aortic grafts as a biological matrix for extensive airway reconstruction. In vivo regeneration of epithelium and cartilage were demonstrated in animal models. This led to the first human applications using cryopreserved aortic allografts that present key advantages because they are available in tissue banks and do not require immunosuppressive therapy. Favorable results obtained in pioneering cases have to be confirmed in larger series of patients with extensive tracheobronchial diseases. PMID:24059453

Martinod, Emmanuel; Seguin, Agathe; Radu, Dana M; Boddaert, Guillaume; Chouahnia, Kader; Fialaire-Legendre, Anne; Dutau, Hervé; Vénissac, Nicolas; Marquette, Charles-Hugo; Baillard, Christophe; Valeyre, Dominique; Carpentier, Alain

2013-01-01

151

Role of transvaginal sonography (TVS) in the detection of endometrial hyperplasia.  

PubMed

Transvaginal sonography is superior to transabdominal sonography in most cases of pelvic pathology. A cross sectional study was done with forty patients to evaluate the clinical usefulness of transvaginal ultrasonography (TVS) in pre, peri and post menopausal women suspected to have endometrial hyperplasia.. The study was carried out January 2007 to November 2008 for a period of two years. The patients having endometrial hyperplasia diagnosed by TVS were correlated with histopathological diagnosis. Of total 40 cases, 18(45.0%) cases were endometrial hyperplasia and 22(55.0%) were negative for endometrial hyperplasia respectively in TVS findings. Only 2 cases were found as negative for endometrial hyperplasia in histopathology among the all suspected endometrial hyperplasia, which were diagnosed by TVS. On the other hand 17(42.5%) cases were endometrial hyperplasia and 23(57.5%) cases were negative for endometrial hyperplasia in histopathological findings. Among 22 negative for endometrial hyperplasia cases which were diagnosed by TVS, 1 case was endometrial hyperplasia and the rest 21 cases were negative for endometrial hyperplasia in histopathological findings. The validity of TVS in diagnosis of endometrial hyperplasia were studied by calculating sensitivity, specificity, accuracy, positive predictive value, which were 94%, 92%, 93%, 89% and 96% respectively. As the TVS findings of the present study correlated well with the histopathology findings and the validity test values were higher than observed by others, it can be concluded that TVS is sensitive and accurate modality in the evaluation of endometrial hyperplasia. PMID:25178606

Showkat, M S; Khondker, L; Nabi, S; Bhowmik, B

2014-07-01

152

Oxidative stress in benign prostate hyperplasia.  

PubMed

Benign Prostate Hyperplasia (BPH) is the common health problem in ageing male. Free radicals and reactive oxygen species (ROS) are produced more with advancement of age leads to oxidative stress. This study aims to assess Malondialdehyde (MDA), the marker of lipid peroxidation and vitaminic antioxidants e.g. alpha-Tocopherol (Toc) and Ascorbate (Asc) status in plasma of BPH patients. This is a case control study conducted in Department of Biochemistry in collaboration with Dept of Surgery, BPKIHS. Forty eight (n = 48) confirmed patients of BPH and forty six (n = 46) healthy age matched controls were enrolled. Plasma MDA, Asc and alpha-Toc were estimated. Plasma MDA level showed 4.81 +/- 1.87 nmol/ml in BPH patients compared to 3.69 +/- 1.56 nmol/ml in healthy controls (p < 0.001). There were significant decrease in plasma alpha-Toc and Asc level which were 0.85 +/- 0.12 mg/dl and 0.93 +/- 0.13 mg/dl in BPH patients compared to 1.37 +/- 0.31 mg/dl and 1.44 +/- 0.38 mg/dl in healthy controls respectively. Inverse correlation of plasma MDA with a- Toc (r = -0.09) and Asc (r = -0.51) was found in BPH patients. There was mild elevation of PSA in BPH patients compared with control but was not statistically significant. Thus, our study showed the evidence of association of oxidative stress in BPH patients. PMID:18298008

Aryal, M; Pandeya, A; Gautam, N; Baral, N; Lamsal, M; Majhi, S; Chandra, L; Pandit, R; Das, B K L

2007-12-01

153

Pathophysiology and management of endometrial hyperplasia and carcinoma.  

PubMed Central

Endometrial cancer is currently the commonest pelvic malignancy affecting American women, most of whom share the same pathophysiologic basis, that is, unopposed estrogenic stimulation. The initial result of hyperestrogenism is the development of endometrial hyperplasia, which is reversible in most cases by appropriate hormonal therapy. Persistent stimulation eventually leads to atypical hyperplasia with nuclear atypia and invasive carcinoma. Because there is no cost-effective screening method for the detection of endometrial hyperplasia and carcinoma, it is essential to survey the high-risk population with appropriate diagnostic techniques. After diagnosis, therapy should be individualized based on pathologic findings (cell type and histologic grade) and extent of disease (International Federation of Gynaecologists and Obstetricians stage, depth of myometrial invasion, and pelvic and para-aortic lymph node status). Recent studies suggest that sex hormone receptors and nuclear DNA ploidy patterns provide useful prognostic information independent of histologic grade. Images PMID:2202159

Fu, Y. S.; Gambone, J. C.; Berek, J. S.

1990-01-01

154

Collagenous spherulosis of the breast with atypical epithelial hyperplasia.  

PubMed

Collagenous spherulosis of the breast is a recently described lesion that was previously been seen only in a setting of benign, typical epitheliosis. We report that unusual case of a collagenous spherulosis of the breast in association with severely atypical epithelial hyperplasia in a 45-year-old woman. The patient presented an asymptomatic right lump and underwent a wide breast tissue resection. After a postoperative follow-up of twelve months, the patient remained well with no breast symptoms. Since atypical hyperplasia in the breast is considered predictive of relatively high risk of later carcinoma development, the finding of collagenous spherulosis with atypical hyperplasia should suggest a long-term follow-up. although at present the biological and prognostic significance of this association is unknown. PMID:8516022

Guarino, M; Tricomi, P; Cristofori, E

1993-01-01

155

Sclerosing Lobular Hyperplasia- Correlation between Cytomorphological and Histological Findings  

PubMed Central

Sclerosing lobular hyperplasia of the mammary gland is an uncommmon benign lesion which is mainly seen in adolescents and young women. The breast lobules are enlarged due to ductal and acinar proliferations but they have normal architecture. There is extensive fibrosis of the intralobular stroma, and to a lesser degree, of the interlobular parenchyma. Patients generally complain of a palpable, painless/slightly tender and well-defined lump in breast. Fine-needle aspiration cytology of sclerosing lobular hyperplasia is non diagnostic with features similar to fibroadneoma except for the absence of stromal fragments. In order to reach a definitive diagnosis, a histopathologic evaluation is needed. However, a distinction between the two benign entities is of no clinical significance.We are describing a case of sclerosing lobular hyperplasia that occurred in the left breast of a 26-year-old lady. PMID:24783103

Lamichaney, Rachna; Sherpa, Mingma; Pradhan, Diwakar

2014-01-01

156

Sclerosing Lobular Hyperplasia- Correlation between Cytomorphological and Histological Findings.  

PubMed

Sclerosing lobular hyperplasia of the mammary gland is an uncommmon benign lesion which is mainly seen in adolescents and young women. The breast lobules are enlarged due to ductal and acinar proliferations but they have normal architecture. There is extensive fibrosis of the intralobular stroma, and to a lesser degree, of the interlobular parenchyma. Patients generally complain of a palpable, painless/slightly tender and well-defined lump in breast. Fine-needle aspiration cytology of sclerosing lobular hyperplasia is non diagnostic with features similar to fibroadneoma except for the absence of stromal fragments. In order to reach a definitive diagnosis, a histopathologic evaluation is needed. However, a distinction between the two benign entities is of no clinical significance.We are describing a case of sclerosing lobular hyperplasia that occurred in the left breast of a 26-year-old lady. PMID:24783103

Lamichaney, Rachna; Sherpa, Mingma; Pradhan, Diwakar

2014-03-01

157

Regenerative Medicine for the Aging Brain  

PubMed Central

In the central nervous system, cholinergic and dopaminergic (DA) neurons are among the cells most susceptible to the deleterious effects of age. Thus, the basal forebrain cholinergic system is known to undergo moderate neurodegenerative changes during normal aging as well as severe atrophy in Alzheimer’s disease (AD). Parkinson’s disease (PD), a degeneration of nigro-striatal DA neurons is the most conspicuous reflection of the vulnerability of DA neurons to age. In this context, cell reprogramming offers novel therapeutic possibilities for the treatment of these devastating diseases. In effect, the generation of induced pluripotent stem cells (iPSCs) from somatic cells demonstrated that adult mammalian cells can be reprogrammed to a pluripotent state by the overexpression of a few embryonic transcription factors (TF). This discovery fundamentally widened the research horizon in the fields of disease modeling and regenerative medicine. Although it is possible to re-differentiate iPSCs to specific somatic cell types, the tumorigenic potential of contaminating iPSCs that failed to differentiate, increases the risk for clinical application of somatic cells generated by this procedure. Therefore, reprogramming approaches that bypass the pluripotent stem cell state are being explored. A method called lineage reprogramming has been recently documented. It consists of the direct conversion of one adult cell type into another by transgenic expression of multiple lineage-specific TF or microRNAs. Another approach, termed direct reprogramming, features several advantages such as the use of universal TF system and the ability to generate a rejuvenated multipotent progenitor cell population, able to differentiate into specific cell types in response to a specific differentiation factors. These novel approaches offer a new promise for the treatment of pathologies associated with the loss of specific cell types as for instance, nigral DA neurons (in PD) or basal forebrain cholinergic neurons in the early stages of AD. The above topics are reviewed here.

Lopez-Leon, Micaela; Reggiani, Paula C.; Herenu, Claudia B.; Goya, Rodolfo G.

2015-01-01

158

Dihydrotestosterone and the Concept of 5?–Reductase Inhibition in Human Benign Prostatic Hyperplasia  

Microsoft Academic Search

Objective:The development of the human benign prostatic hyperplasia clearly requires a combination of testicular androgens and aging. Although the role of androgens as the causative factor for human benign prostatic hyperplasia is debated, they undoubtedly have at least a permissive role. The principal prostatic androgen is dihydrotestosterone (DHT). Although not elevated in human benign prostatic hyperplasia, DHT levels in the

G. Bartsch; R. S. Rittmaster; H. Klocker

2000-01-01

159

Dihydrotestosterone and the concept of 5a-reductase inhibition in human benign prostatic hyperplasia  

Microsoft Academic Search

The development of human benign prostatic hyperplasia (BPH) clearly requires a combination of testicular androgens and the ageing process. Although the role of androgens as the causative factor for human benign prostatic hyperplasia is debated, they undoubtedly play, at least, a permissive role. The principal prostatic androgen is dihydrotestosterone. Although not elevated in human benign prostatic hyperplasia, dihydrotestosterone levels in

G. Bartsch; R. Rittmaster; H. Klocker

2002-01-01

160

Estrogenic action of commonly used fragrant agent citral induces prostatic hyperplasia  

Microsoft Academic Search

A rat model for benign prostatic hyperplasia in man (BPH) was investigated. Citral treatment of male Copenhagen rats for 4 months via the transdermal route resulted in a marked hyperplasia of glandular epithelium and interglandular stroma in the ventral prostate. Despite the cellular hyperplasia there was not a significant increase in prostate weight. Investigations of the mechanism of action of

A. A. Geldof; C. Engel; B. R. Rao

1992-01-01

161

Advanced biomatrix designs for regenerative therapy of periodontal tissues.  

PubMed

Periodontitis is an inflammatory disease that causes loss of the tooth-supporting apparatus, including periodontal ligament, cementum, and alveolar bone. A broad range of treatment options is currently available to restore the structure and function of the periodontal tissues. A regenerative approach, among others, is now considered the most promising paradigm for this purpose, harnessing the unique properties of stem cells. How to make full use of the body's innate regenerative capacity is thus a key issue. While stem cells and bioactive factors are essential components in the regenerative processes, matrices play pivotal roles in recapitulating stem cell functions and potentiating therapeutic actions of bioactive molecules. Moreover, the positions of appropriate bioactive matrices relative to the injury site may stimulate the innate regenerative stem cell populations, removing the need to deliver cells that have been manipulated outside of the body. In this topical review, we update views on advanced designs of biomatrices-including mimicking of the native extracellular matrix, providing mechanical stimulation, activating cell-driven matrices, and delivering bioactive factors in a controllable manner-which are ultimately useful for the regenerative therapy of periodontal tissues. PMID:25139364

Kim, J H; Park, C H; Perez, R A; Lee, H Y; Jang, J H; Lee, H H; Wall, I B; Shi, S; Kim, H W

2014-12-01

162

A novel unitized regenerative proton exchange membrane fuel cell  

NASA Technical Reports Server (NTRS)

A difficulty encountered in designing a unitized regenerative proton exchange membrane (PEM) fuel cell lies in the incompatibility of electrode structures and electrocatalyst materials optimized for either of the two functions (fuel cell or electrolyzer) with the needs of the other function. This difficulty is compounded in previous regenerative fuel cell designs by the fact that water, which is needed for proton conduction in the PEM during both modes of operation, is the reactant supplied to the anode in the electrolyzer mode of operation and the product formed at the cathode in the fuel cell mode. Drawbacks associated with existing regenerative fuel cells have been addressed in work performed at Lynntech. In a first innovation, electrodes function either as oxidation electrodes (hydrogen ionization or oxygen evolution) or as reduction electrodes (oxygen reduction or hydrogen evolution) in the fuel cell and electrolyzer modes, respectively. Control of liquid water within the regenerative fuel cell has been brought about by a second innovation. A novel PEM has been developed with internal channels that permit the direct access of water along the length of the membrane. Lateral diffusion of water along the polymer chains of the PEM provides the water needed at electrode/PEM interfaces. Fabrication of the novel unitized regenerative fuel cell and results obtained on testing it will be presented.

Murphy, O. J.; Cisar, A. J.; Gonzalez-Martin, A.; Salinas, C. E.; Simpson, S. F.

1995-01-01

163

A novel unitized regenerative proton exchange membrane fuel cell  

NASA Astrophysics Data System (ADS)

A difficulty encountered in designing a unitized regenerative proton exchange membrane (PEM) fuel cell lies in the incompatibility of electrode structures and electrocatalyst materials optimized for either of the two functions (fuel cell or electrolyzer) with the needs of the other function. This difficulty is compounded in previous regenerative fuel cell designs by the fact that water, which is needed for proton conduction in the PEM during both modes of operation, is the reactant supplied to the anode in the electrolyzer mode of operation and the product formed at the cathode in the fuel cell mode. Drawbacks associated with existing regenerative fuel cells have been addressed in work performed at Lynntech. In a first innovation, electrodes function either as oxidation electrodes (hydrogen ionization or oxygen evolution) or as reduction electrodes (oxygen reduction or hydrogen evolution) in the fuel cell and electrolyzer modes, respectively. Control of liquid water within the regenerative fuel cell has been brought about by a second innovation. A novel PEM has been developed with internal channels that permit the direct access of water along the length of the membrane. Lateral diffusion of water along the polymer chains of the PEM provides the water needed at electrode/PEM interfaces. Fabrication of the novel unitized regenerative fuel cell and results obtained on testing it will be presented.

Murphy, O. J.; Cisar, A. J.; Gonzalez-Martin, A.; Salinas, C. E.; Simpson, S. F.

1995-04-01

164

A Novel Unitized Regenerative Proton Exchange Membrane Fuel Cell  

NASA Technical Reports Server (NTRS)

A difficulty encountered in designing a unitized regenerative proton exchange membrane (PEM) fuel cell lies in the incompatibility of electrode structures and electrocatalyst materials optimized for either of the two functions (fuel cell or electrolyzer) with the needs of the other function. This difficulty is compounded in previous regenerative fuel cell designs by the fact that water, which is needed for proton conduction in the PEM during both modes of operation, is the reactant supplied to the anode in the electrolyzer mode of operation and the product formed at the cathode in the fuel cell mode. Drawbacks associated with existing regenerative fuel cells have been addressed. In a first innovation, electrodes function either as oxidation electrodes (hydrogen ionization or oxygen evolution) or as reduction electrodes (oxygen reduction or hydrogen evolution) in the fuel cell and electrolyzer modes, respectively. Control of liquid water within the regenerative fuel cell has been brought about by a second innovation. A novel PEM has been developed with internal channels that permit the direct access of water along the length of the membrane. Lateral diffusion of water along the polymer chains of the PEM provides the water needed at electrode/PEM interfaces. Fabrication of the novel single cell unitized regenerative fuel cell and results obtained on testing it are presented.

Murphy, O. J.; Cisar, A. J.; Gonzalez-Martin, A.; Salinas, C. E.; Simpson, S. F.

1996-01-01

165

Erich Regener and the ionisation maximum of the atmosphere  

NASA Astrophysics Data System (ADS)

In the 1930s the German physicist Erich Regener (1881-1955) did important work on the measurement of the rate of production of ionisation deep under water and in the atmosphere. Along with one of his students, Georg Pfotzer, he discovered the altitude at which the production of ionisation in the atmosphere reaches a maximum, often, but misleadingly, called the Pfotzer maximum. Regener was one of the first to estimate the energy density of cosmic rays, an estimate that was used by Baade and Zwicky to bolster their postulate that supernovae might be their source. Yet Regener's name is less recognised by present-day cosmic ray physicists than it should be, largely because in 1937 he was forced to take early retirement by the National Socialists as his wife had Jewish ancestors. In this paper we briefly review his work on cosmic rays and recommend an alternative naming of the ionisation maximum. The influence that Regener had on the field through his son, his son-in-law, his grandsons and his students, and through his links with Rutherford's group in Cambridge, is discussed in an appendix. Regener was nominated for the Nobel Prize in Physics by Schrödinger in 1938. He died in 1955 at the age of 73.

Carlson, P.; Watson, A. A.

2014-12-01

166

Regenerative Endodontics: Barriers and Strategies for Clinical Translation  

PubMed Central

SYNOPSIS Despite a great deal of enthusiasm and effort, regenerative endodontics has encountered substantial challenges towards clinical translation. Recent adoption by the American Dental Association (ADA) of evoked pulp bleeding in immature permanent teeth is an important step for regenerative endodontics. However, there is no regenerative therapy for the majority of endodontic diseases. Simple recapitulation of cell therapy and tissue engineering strategies that are under development for other organ systems has not led to clinical translation in regeneration endodontics. Dental pulp stem cells may appear to be a priori choice for dental pulp regeneration. However, dental pulp stem cells may not be available in a patient who is in need of pulp regeneration. Even if dental pulp stem cells are available autologously or perhaps allogeneically, one must address a multitude of scientific, regulatory and commercialization barriers, and unless these issues are resolved, transplantation of dental pulp stem cells will remain a scientific exercise, rather than a clinical reality. Recent work using novel biomaterial scaffolds and growth factors that orchestrate the homing of host endogenous cells represents a departure from traditional cell transplantation approaches and may accelerate clinical translation. Given the functions and scale of dental pulp and dentin, regenerative endodontics is poised to become one of the early biological solutions in regenerative dental medicine. PMID:22835543

Kim, Sahng G.; Zhou, Jian; Ye, Ling; Cho, Shoko; Suzuki, Takahiro; Fu, Susan Y.; Yang, Rujing; Zhou, Xuedong; Mao, Jeremy J.

2014-01-01

167

Regenerative Potential of Endometrial Stem Cells: A Mini Review  

PubMed Central

Recent findings in stem cell biology have opened a new window in regenerative medicine. The endometrium possesses mesenchymal stem cells (MSCs) called endometrial stem cells (EnSCs) having specific regenerative properties linked to adult stem cells. They contribute in tissue remodeling and engineering and were shown to have immuno-modulating effects. Many clinical trials were undertaken to ascertain the therapeutic potential of EnSCS. In this mini review, we showed that EnSCs are readily available sources of adult stem cells in the uterus that can be highlighted for their renewable multipotent and differentiation properties. This cell population may be a practical solution of choice in reproductive biology, regenerative medicine and autologous stem cell therapy. PMID:25606470

Ghobadi, Farnaz; Mehrabani, Davood; Mehrabani, Golnoush

2015-01-01

168

Proteins and Small Molecules for Cellular Regenerative Medicine  

PubMed Central

Regenerative medicine seeks to understand tissue development and homeostasis and build on that knowledge to enhance regeneration of injured tissues. By replenishing lost functional tissues and cells, regenerative medicine could change the treatment paradigm for a broad range of degenerative and ischemic diseases. Multipotent cells hold promise as potential building blocks for regenerating lost tissues, but successful tissue regeneration will depend on comprehensive control of multipotent cells–differentiation into a target cell type, delivery to a desired tissue, and integration into a durable functional structure. At each step of this process, proteins and small molecules provide essential signals and, in some cases, may themselves act as effective therapies. Identifying these signals is thus a fundamental goal of regenerative medicine. In this review we discuss current progress using proteins and small molecules to regulate tissue regeneration, both in combination with cellular therapies and as monotherapy. PMID:23303911

Green, Eric M.

2013-01-01

169

Electric vehicle regenerative antiskid braking and traction control system  

DOEpatents

An antiskid braking and traction control system for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes one or more sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensors and determining if regenerative antiskid braking control, requiring hydrualic braking control, or requiring traction control are required. The processor then employs a control strategy based on the determined vehicle state and provides command signals to a motor controller to control the operation of the electric traction motor and to a brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative antiskid braking control, hydraulic braking control, and traction control.

Cikanek, Susan R. (Wixom, MI)

1995-01-01

170

Learning Disabilities in Children With Congenital Adrenal Hyperplasia  

Microsoft Academic Search

Early exposure to androgens may be a cause of the higher incidence of learning disabilities among males. To test this hypothesis, we determined the frequency of learning disabilities, as measured by extent of Wechsler Verbal-Performance IQ discrepancy, among female patients with congenital adrenal hyperplasia, who are exposed in utero to excess androgens for their sex. A significantly larger Verbal-Performance IQ

Ruth Nass; Susan Baker

1991-01-01

171

Psychosexual Development of Women with Congenital Adrenal Hyperplasia  

Microsoft Academic Search

Women with congenital adrenal hyperplasia (CAH) (N= 31) and their unaffected sisters or female cousins (N= 15) participated in a study of psychosexual development. All participants were ?18 years of age (mean age, 25 years; range, 18–40). Comparisons were also made between the CAH women with the salt-wasting (SW) form of the disorder and those with simple virilization (SV). A

Kenneth J. Zucker; Susan J. Bradley; Gillian Oliver; Jennifer Blake; Susan Fleming; Jane Hood

1996-01-01

172

Focal fibrous hyperplasia: A review of 193 cases  

PubMed Central

Context: Focal fibrous hyperplasia, also known as irritation or traumatic fibroma, is a reactive, inflammatory hyperplastic lesion of the connective tissue. Aim: The aim of this study is to perform a retrospective study of a focal fibrous hyperplasia of 18 years. Materials and Methods: We retrospectively reviewed 193 cases of focal fibrous hyperplasia of the oral cavity from the medical and histological reports of the Department of Oral Pathology, Pernambuco University, Brazil, during the period between January 1992 and December 2009. Settings and Design: Data with regard to age, gender, location, size of the lesion (equal to or less than 1 cm, between 1 and 2 cm and greater than 2 cm), pain, history of trauma, treatment, length of follow-up (from diagnosis to release or last review) and recurrence, were collected. Results: The most commonly affected site was the buccal mucosa (n = 119, 61.7%). Almost two-thirds of the cases were concentrated from the second to the fifth decade of life. Females were more affected than men and a history of trauma was related by 90.7% of the patients. Two recurrences were notified (1.0%). Conclusion: Further studies are needed on the distribution of the lesion in different ethnic and geographical populations. The influence of sex hormones on the development of focal fibrous hyperplasia must be clarified. PMID:25364187

de Santana Santos, Thiago; Martins-Filho, Paulo Ricardo Saquete; Piva, Marta Rabello; de Souza Andrade, Emanuel Sávio

2014-01-01

173

Prenatal and Neonatal Diagnosis and Treatment of Congenital Adrenal Hyperplasia  

Microsoft Academic Search

Background: Clinical management of patients with congenital adrenal hyperplasia (CAH) involves treating hormonal deficiencies, addressing issues related to genital ambiguity, avoiding morbidities and communicating with the family about risk of CAH in other members. This article briefly reviews the prenatal and neonatal diagnosis of CAH caused by steroid 21-hydroxylase deficiency, as well as treatment options and neonatal screening approaches. Conclusions:

Phyllis W. Speiser

2007-01-01

174

The underestimated role of neointimal hyperplasia: balloon folding  

E-print Network

The underestimated role of neointimal hyperplasia: balloon folding M. De Beule, P. Mortier, D. Van and expansion data from both stents and balloons Virtual expansion of the Cypher (Cordis) stent by the inflation of a trifolded Raptor balloon using ABAQUS FEA software The balloon folding pattern seems a major factor

Gent, Universiteit

175

A high-power compact regenerative amplifier FEL  

SciTech Connect

The Regenerative Amplifier FEL (RAFEL) is a new FEL approach aimed at achieving the highest optical power from a compact rf-linac FEL. The key idea is to feed back a small fraction (< 10%) of the optical power into a high-gain ({approximately}10{sup 5} in single pass) wiggler to enable the FEL to reach saturation in a few passes. This paper summarizes the design of a high-power compact regenerative amplifier FEL and describes the first experimental demonstration of the RAFEL concept.

Nguyen, D.C.; Sheffield, R.L.; Fortgang, C.M.; Kinross-Wright, J.M.; Ebrahim, N.A.; Goldstein, J.C.

1997-08-01

176

Regenerative medicine and stem cell based drug discovery.  

PubMed

As William Shakespeare beautifully described, increasing age often causes loss of tissue and organ function. The increase in average life expectancy in many countries is generating an aging society and an increase in age-related health problems. Regenerative medicine is expected to be a powerful actor in this drama, and stem cell technology may hold the key to the development of innovative treatments for acute and chronic degenerative conditions. This Review surveys the present situation and some future prospects for regenerative medicine and stem cell based drug discovery. PMID:18624353

Sakurada, Kazuhiro; McDonald, Fiona M; Shimada, Fumiki

2008-01-01

177

Research requirements for development of regenerative engines for helicopters  

NASA Technical Reports Server (NTRS)

The improved specific fuel consumption of the regenerative engine was compared to a simple-cycle turboshaft engine. The performance improvement and fuel saving are obtained at the expense of increased engine weight, development and production costs, and maintenance costs. Costs and schedules are estimated for the elements of the research and development program. Interaction of the regenerative engine with other technology goals for an advanced civil helicopter is examined, including its impact on engine noise, hover and cruise performance, helicopter empty weight, drive-system efficiency and weight, one-engine-inoperative hover capability, and maintenance and reliability.

Semple, R. D.

1976-01-01

178

Ignition feedback regenerative free electron laser (FEL) amplifier  

DOEpatents

An ignition feedback regenerative amplifier consists of an injector, a linear accelerator with energy recovery, and a high-gain free electron laser amplifier. A fraction of the free electron laser output is coupled to the input to operate the free electron laser in the regenerative mode. A mode filter in this loop prevents run away instability. Another fraction of the output, after suitable frequency up conversion, is used to drive the photocathode. An external laser is provided to start up both the amplifier and the injector, thus igniting the system.

Kim, Kwang-Je (Burr Ridge, IL); Zholents, Alexander (Walnut Creek, CA); Zolotorev, Max (Oakland, CA)

2001-01-01

179

Qualifying Exam Guidelines for the Developmental, Regenerative and Stem Cell Biology General Knowledge Exam  

E-print Network

Qualifying Exam Guidelines for the Developmental, Regenerative and Stem Cell Biology Program. General Knowledge Exam The Developmental, Regenerative and Stem Cell Biology (DRS) Program's General different faculty members on the following four subjects: Developmental Biology, Genetics, Cell Biology

Gereau, Robert W. IV

180

Predicting Forest Regeneration in the Central Appalachians Using the REGEN Expert System  

Microsoft Academic Search

REGEN is an expert system designed by David Loftis to predict the future species composition of dominant and codominant stems in forest stands at the onset of stem exclusion following a proposed harvest. REGEN predictions are generated using competitive rankings for advance reproduction along with other existing stand conditions. These parameters are contained within modular REGEN knowledge bases (RKBs). To

Lance A. Vickers; Thomas R. Fox; David L. Loftis; David A. Boucugnani

2011-01-01

181

High energy density regenerative fuel cell systems for terrestrial applications  

Microsoft Academic Search

Regenerative Fuel Cell System (RFCS) technology for energy storage has been a NASA power system concept for many years. Compared to battery-based energy storage systems, RFCS has received relatively little attention or resources for development because the energy density and electrical efficiency were not sufficiently attractive relative to advanced battery systems. Even today, RFCS remains at a very low technology

K. A. Burke

1999-01-01

182

Frequency-Domain Analysis of Super-Regenerative Amplifiers  

E-print Network

Since its invention in 1922, the super-regenerative amplifier (SRA) has been used in a variety of short-range, low-power, and/or low-cost wireless systems due to its simple implementation and excellent performance for a ...

Dawson, Joel L.

183

Feasibility Study of Regenerative Burners in Aluminum Holding Furnaces  

NASA Astrophysics Data System (ADS)

Gas-fired aluminum holding reverberatory furnaces are currently considered to be the lowest efficiency fossil fuel system. A considerable volume of gas is consumed to hold the molten metal at temperature that is much lower than the flame temperature. This will lead to more effort and energy consumption to capture the excessive production of the CO2. The concern of this study is to investigate the feasibility of the regenerative-burners' furnaces to increase the furnace efficiency to reduce gas consumption per production and hence result in less CO2 production. Energy assessments for metal holding furnaces are considered at different operation conditions. Onsite measurements, supervisory control and data acquisition data, and thermodynamics analysis are performed to provide feasible information about the gas consumption and CO2 production as well as area of improvements. In this study, onsite measurements are used with thermodynamics modeling to assess a 130 MT rectangular furnace with two regenerative burners and one cold-air holding burner. The assessment showed that the regenerative burner furnaces are not profitable in saving energy, in addition to the negative impact on the furnace life. However, reducing the holding and door opening time would significantly increase the operation efficiency and hence gain the benefit of the regenerative technology.

Hassan, Mohamed I.; Al Kindi, Rashid

2014-09-01

184

Status of the Regenerative ECLS Water Recovery System  

NASA Technical Reports Server (NTRS)

The regenerative Water Recovery System (WRS) has completed its first full year of operation on the International Space Station (ISS). The major assemblies included in this system are the Water Processor Assembly (WPA) and Urine Processor Assembly (UPA). This paper summarizes the on-orbit status as of May 2010, and describes the technical challenges encountered and lessons learned over the past year.

Carter, Donald Layne

2010-01-01

185

Bromodeoxyuridine Specifically Labels the Regenerative Stem Cells of Planarians  

Microsoft Academic Search

The singular regenerative abilities of planarians require a population of stem cells known as neoblasts. In response to wounding, or during the course of cell turnover, neoblasts are signaled to divide and\\/or differentiate, thereby replacing lost cell types. The study of these pluripotent stem cells and their role in planarian regeneration has been severely hampered by the reported inability of

Phillip A. Newmark; Alejandro Sánchez Alvarado

2000-01-01

186

Mesenchymal stem cells for tissue engineering and regenerative medicine  

Microsoft Academic Search

Mesenchymal stem cells (MSCs) exist in bone marrow and other musculoskeletal tissues. These cells contribute to the homeostasis of musculoskeletal tissue as well as support for the growth and differentiation of primitive hemopoietic cells. Recent advancements in tissue engineering and regenerative medicine have highlighted MSCs as a potential source of cells which would differentiate to a variety of tissue tailored

Suk-Kee Tae; Seok-Hyn Lee; Jae-Sik Park; Gun-Il Im

2006-01-01

187

Permanent magnet synchronous generators for regenerative energy conversion - a survey  

Microsoft Academic Search

A survey on recently installed or developed permanent magnet (PM) synchronous generators for energy conversion in regenerative and alternative power supply systems is given. Its focus is for low speed machines on geared and gearless PM generator systems for wind power plants and small PM hydro generators in gearless coupling. For distributed co-generation of heat and electrical power by micro

Andreas Binder; Tobias Schneider

2005-01-01

188

California Institute for Regenerative Medicine (CIRM) Stem Cell Basics Videos  

NSDL National Science Digital Library

This collection of videos, from the California Institute for Regenerative Medicine, features researchers as they "explain the basics of stem cell research and discuss the many hurdles in translating the basic research into new therapies." Some of the topics covered here include: creating embryonic stem cell lines, therapies based on cancer stem cells, therapy development, stem cell differentiation, ethics, and more.

2012-03-28

189

A Regeneratively Cooled Thrust Chamber For The Fastrac Engine  

NASA Technical Reports Server (NTRS)

Abstract This paper presents the development of a low-cost, regeneratively-cooled thrust chamber for the Fastrac engine. The chamber was fabricated using hydraformed copper tubing to form the coolant jacket and wrapped with a fiber reinforced polymer composite Material to form a structural jacket. The thrust chamber design and fabrication approach was based upon Space America. Inc.'s 12,000 lb regeneratively-cooled LOX/kerosene rocket engine. Fabrication of regeneratively cooled thrust chambers by tubewall construction dates back to the early US ballistic missile programs. The most significant innovations in this design was the development of a low-cost process for fabrication from copper tubing (nickel alloy was the usual practice) and use of graphite composite overwrap as the pressure containment, which yields an easily fabricated, lightweight pressure jacket around the copper tubes A regeneratively-cooled reusable thrust chamber can benefit the Fastrac engine program by allowing more efficient (cost and scheduler testing). A proof-of-concept test article has been fabricated and will he tested at Marshall Space Flight Center in the late Summer or Fall of 2000.

Brown, Kendall K.; Sparks, Dave; Woodcock, Gordon

2000-01-01

190

Induced pluripotent stem cells: developmental biology to regenerative medicine  

Microsoft Academic Search

Nuclear reprogramming of somatic cells with ectopic stemness factors to bioengineer pluripotent autologous stem cells signals a new era in regenerative medicine. The study of developmental biology has provided a roadmap for cardiac differentiation from embryonic tissue formation to adult heart muscle rejuvenation. Understanding the molecular mechanisms of stem-cell-derived cardiogenesis enables the reproducible generation, isolation, and monitoring of progenitors that

Almudena Martinez-Fernandez; Andre Terzic; Timothy J. Nelson

2010-01-01

191

Regenerative Snubber For GTO-Commutated SCR Inverter  

NASA Technical Reports Server (NTRS)

Proposed regenerative snubbing circuit substituted for dissipative snubbing circuit in inverter based on silicon controlled rectifiers (SCR's) commutated by gate-turn-off thyristor (GTO). Intended to reduce loss of power that occurs in dissipative snubber. Principal criteria in design: low cost, simplicity, and reliability.

Rippel, Wally E.; Edwards, Dean B.

1992-01-01

192

Regenerative cooling for liquid propellant rocket thrust chambers  

Microsoft Academic Search

This work describes a calculation model for regeneratively cooled rocket thrust chambers. A computational program, based on a one-dimensional coolant pressure drop in the cooling channels. Radiation is included in the model. The channels have rectangular cross sections, the dimensions being determined during the calculations in order to maintain the wall temperature distributions at tolerable levels, with a minimum channel

Rafael Levy Rubin

1994-01-01

193

Mesenchymal stem cell secretome and regenerative therapy after cancer.  

PubMed

Cancer treatment generally relies on tumor ablative techniques that can lead to major functional or disfiguring defects. These post-therapy impairments require the development of safe regenerative therapy strategies during cancer remission. Many current tissue repair approaches exploit paracrine (immunomodulatory, pro-angiogenic, anti-apoptotic and pro-survival effects) or restoring (functional or structural tissue repair) properties of mesenchymal stem/stromal cells (MSC). Yet, a major concern in the application of regenerative therapies during cancer remission remains the possible triggering of cancer recurrence. Tumor relapse implies the persistence of rare subsets of tumor-initiating cancer cells which can escape anti-cancer therapies and lie dormant in specific niches awaiting reactivation via unknown stimuli. Many of the components required for successful regenerative therapy (revascularization, immunosuppression, cellular homing, tissue growth promotion) are also critical for tumor progression and metastasis. While bi-directional crosstalk between tumorigenic cells (especially aggressive cancer cell lines) and MSC (including tumor stroma-resident populations) has been demonstrated in a variety of cancers, the effects of local or systemic MSC delivery for regenerative purposes on persisting cancer cells during remission remain controversial. Both pro- and anti-tumorigenic effects of MSC have been reported in the literature. Our own data using breast cancer clinical isolates have suggested that dormant-like tumor-initiating cells do not respond to MSC signals, unlike actively dividing cancer cells which benefited from the presence of supportive MSC. The secretome of MSC isolated from various tissues may partially diverge, but it includes a core of cytokines (i.e. CCL2, CCL5, IL-6, TGF?, VEGF), which have been implicated in tumor growth and/or metastasis. This article reviews published models for studying interactions between MSC and cancer cells with a focus on the impact of MSC secretome on cancer cell activity, and discusses the implications for regenerative therapy after cancer. PMID:23747841

Zimmerlin, Ludovic; Park, Tea Soon; Zambidis, Elias T; Donnenberg, Vera S; Donnenberg, Albert D

2013-12-01

194

Regenerative Wound Healing: The Role of Interleukin-10  

PubMed Central

Significance: Postnatal wounds heal with characteristic scar formation. In contrast, the mid-gestational fetus is capable of regenerative healing, which results in wound repair that is indistinguishable from uninjured skin. However, the underlying mechanisms of fetal regenerative phenotype are unknown. Recent Advances: The potent anti-inflammatory cytokine, interleukin-10 (IL-10), plays an essential role in the ability of the fetus to heal regeneratively and has been shown to recapitulate scarless healing in postnatal tissue. IL-10's ability to facilitate regenerative healing is likely a result of pleiotropic effects, through regulation of the inflammatory response, as well as novel roles as a regulator of the extracellular matrix, fibroblast cellular function, and endothelial progenitor cells. Overexpression of IL-10 using a variety of methods has been demonstrated to recapitulate the fetal regenerative phenotype in post-natal tissue, in conjunction with promising results of Phase II clinical trials using recombinant IL-10. Critical Issues: Successful wound healing is a complex process that requires coordination of multiple growth factors, cell types, and extracellular cellular matrix components. IL-10 has been demonstrated to be critical in the fetus' intrinsic ability to heal without scars, and, further, can induce scarless healing in postnatal tissue. The mechanisms through which IL-10 facilitates this regeneration are likely the result of IL-10's pleiotropic effects. Efforts to develop IL-10 as an anti-scarring agent have demonstrated promising results. Future Directions: Further studies on the delivery, including dose, route, and timing, are required in order to successfully translate these promising findings from in vitro studies and animal models into clinical practice. IL-10 holds significant potential as an anti-scarring therapeutic. PMID:24757588

King, Alice; Balaji, Swathi; Le, Louis D.; Crombleholme, Timothy M.; Keswani, Sundeep G.

2014-01-01

195

Genome-wide expression profile of the response to spinal cord injury in Xenopus laevis reveals extensive differences between regenerative and non-regenerative stages  

PubMed Central

Background Xenopus laevis has regenerative and non-regenerative stages. As a tadpole, it is fully capable of functional recovery after a spinal cord injury, while its juvenile form (froglet) loses this capability during metamorphosis. We envision that comparative studies between regenerative and non-regenerative stages in Xenopus could aid in understanding why spinal cord regeneration fails in human beings. Results To identify the mechanisms that allow the tadpole to regenerate and inhibit regeneration in the froglet, we obtained a transcriptome-wide profile of the response to spinal cord injury in Xenopus regenerative and non-regenerative stages. We found extensive transcriptome changes in regenerative tadpoles at 1 day after injury, while this was only observed by 6 days after injury in non-regenerative froglets. In addition, when comparing both stages, we found that they deployed a very different repertoire of transcripts, with more than 80% of them regulated in only one stage, including previously unannotated transcripts. This was supported by gene ontology enrichment analysis and validated by RT-qPCR, which showed that transcripts involved in metabolism, response to stress, cell cycle, development, immune response and inflammation, neurogenesis, and axonal regeneration were regulated differentially between regenerative and non-regenerative stages. Conclusions We identified differences in the timing of the transcriptional response and in the inventory of regulated transcripts and biological processes activated in response to spinal cord injury when comparing regenerative and non-regenerative stages. These genes and biological processes provide an entry point to understand why regeneration fails in mammals. Furthermore, our results introduce Xenopus laevis as a genetic model organism to study spinal cord regeneration. PMID:24885550

2014-01-01

196

Oral Focal Epithelial Hyperplasia: Report of Three Cases.  

PubMed

Focal epithelial hyperplasia or Heck's disease is an infrequent asymptomatic condition caused by human papillomavirus types 13 or 32 affecting the mucous membrane of the mouth and is commonly seen in young individuals. Firstly, it was described in Indians and Eskimos, but it exists in various populations. We present three cases of Heck's disease in an Afghan immigrant family group living in Iran that seem to have familial predominance. The disease was identified as oral focal epithelial hyperplasia on the basis of histopathologic and clinical findings. The lesions were reduced significantly after 4 months of good oral hygiene. Dentists should be familiar with the clinical manifestations of these types of lesions that affect the oral cavity. In fact, histopathologic assessment and clinical observation are necessary to establish the diagnosis. PMID:24585348

Ghalayani, Parichehr; Tavakoli, Payam; Eftekhari, Mehdi; Haghighi, Mohammad Akhondzadeh

2014-02-27

197

Minimally invasive surgery for coronoid hyperplasia: endoscopically assisted intraoral coronoidectomy.  

PubMed

The term hyperplasia of the coronoid process of the mandible defines an abnormal elongation of the coronoid process consisting of histologically normal bone. The main clinical finding of hyperplasia of the coronoid process is a progressive painless difficulty in opening the mouth owing to the contact with the temporal surface of the zygomatic bone or medial surface of the zygomatic arch. Computed tomography with three-dimensional reconstruction is essential and is the gold standard for an accurate diagnosis. The etiology remains unknown, although several theories have been suggested. The main aim of treatment was to restore mouth opening, and this article introduces and illustrates the advantages of endoscopic assistance for coronoidectomy through the classic "intraoral" approach and emphasize this minimally invasive approach. PMID:23147302

Robiony, Massimo; Casadei, Matteo; Costa, Fabio

2012-11-01

198

Pituitary hyperplasia secondary to acquired hypothyroidism: case report  

PubMed Central

Objective and Importance despite recent progress in imaging, it is still difficult to distinguish between pituitary adenoma and hyperplasia, even using Magnetic Resonance Imaging (MRI) with gadolinium injection. We describe an example of reactive pituitary hyperplasia from primary hypothyroidism that mimicked a pituitary macroadenoma in a child. Clinical Presentation a 10 year old boy presented with headache and statural growth arrest. MRI revealed an intrasellar and suprasellar pituitary mass. Endocrine evaluation revealed primary hypothyroidism. Intervention the patient was started on levothyroxine with resolution of the mass effect. Conclusion primary hypothyroidism should be considered in the differential diagnosis of solid mass lesions of the pituitary gland. Examination of thyroid function in patients with sellar and suprasellar masses revealed by MRI may avoid unnecessary operations which can cause irreversible complications. PMID:21473748

2011-01-01

199

[Turner's syndrome with pituitary hyperplasia: a case report].  

PubMed

Turner's syndrome, a sex-chromosome abnormality, is often accompanied by cardiovascular disorders, such as coarctation of the aorta. We encountered a case of Turner's syndrome with meningioma and pituitary hyperplasia which resulted in death from dissection of the aorta. The patient was 36-year-old female who was diagnosed as having Turner's syndrome of mosaic-type at the age of 15. She had accepted sex-hormone replacement with estrogen and progesterone over 20 years. She lost consciousness and was transferred to our institute on June 20th, 1992. She was in shock but her condition began to improve after intensive treatment. CT scan revealed a calcified mass lesion at the left frontal convexity and a markedly enhanced round mass lesion at the suprasellar region. Angiography showed tumor stain of the suprasellar region fed by the posterior ethmoidal artery. These tumors were diagnosed as multiple meningiomas. She developed dyspnea on June 24th and chest X-ray showed right pleural fluid collection and cardiomegaly. This condition was diagnosed as congestive heart failure. Her condition was getting worse and she suffered abrupt cardiac arrest on June 28th. Autopsy revealed dissection of the aorta as the cause of death. The tumor of the convexity was meningioma, and the suprasellar lesion was diagnosed as pituitary hyperplasia. It is well known that frequent excess dose injection of estrogen can induce pituitary adenoma or hyperplasia in rats. In this case, the presence of pituitary hyperplasia was thought to be the result of long-term injection of estrogen.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8164797

Kido, G; Miyagi, A; Shibuya, T; Miyagami, M; Tsubokawa, T; Sawada, T

1994-04-01

200

Angiolymphoid hyperplasia with eosinophilia. A report of two cases.  

PubMed

Angiolymphoid hyperplasia with eosinophilia is a benign vascular neoplasm characterized by marked proliferation of large endothelial cells and an inflammatory infiltrate of lymphocytes, histiocytes, and eosinophiles. The condition must be differentiated from malignant vascular tumors and from several other benign conditions. Although lesions may be ablated by several means of treatment, there is a tendency to recurrence, but, even untreated, there is a tendency to eventual spontaneous regression. PMID:7229181

Baler, G R

1981-03-01

201

Therapeutic options in the treatment of benign prostatic hyperplasia  

PubMed Central

Current theraputic options for the treatment of symptomatic benign prostatic hyperplasia (BPH) are reviewed. Therapeutic options for mild lower urinary tract symptoms (LUTS), as defined by the American Urological Association, are generally treated medically. Moderate to severe LUTS can be treated medically or with surgical therapy. Current medical and surgical treatments for LUTS secondary to BPH are reviewed and evolving treatments are explored. PMID:19936164

Sandhu, Jaspreet S

2009-01-01

202

Supernumerary nostril: Congenital adrenal hyperplasia with a rare congenital anomaly  

PubMed Central

Multiple or supernumerary nostril is a rare congenital anomaly with unknown etiology. The first case was reported by Lindsay as bilateral supernumerary nostrils. Supernumerary nostril cases are mostly unilateral and isolated. They are also reported with other congenital malformations like facial clefts and congenital anomalies like congenital auricular hypoplasia, congenital cataracts, eusophageal atresia and patent ductus arteriosus. Here, we report a case of supernumerary nostril with congenital adrenal hyperplasia

Ciloglu, Sinem; Duran, Alpay; Buyukdogan, Hasan; Yigit, Ahmet K.

2014-01-01

203

Management of Congenital Adrenal Hyperplasia: Results of the ESPE Questionnaire  

Microsoft Academic Search

The management of children and adolescents with congenital adrenal hyperplasia (CAH) remains difficult. To assess the current European practice in diagnosis and management of CAH, an ESPE (European Society for Paediatric Endocrinology) survey was circulated in 2000\\/2001. The questionnaire was answered by 34% of ESPE members, representing 125 institutions which cared for 6,553 CAH patients. Paediatric endocrinologists, surgeons, gynaecologists, geneticists,

Felix G. Riepe; Nils Krone; Matthias Viemann; Carl-Joachim Partsch; Wolfgang G. Sippell

2002-01-01

204

Structural characterization of [(?-H)Os 3(CO) 10(?-NH 2)] and a new polymorphic form of [(?-H)Os 3(CO) 10(?-SH)]. Influence of the bridging group on the geometry of compounds [(?-H)Os 3(CO) 10(?-X)] (X = NH 2, NRH, PRH, SbR 2, OH, SH, SR, SeR, Cl, Br). Reactions of [(?-H)Os 3(CO) 10(?-X)] (X = OH and SH) with proton sponge  

NASA Astrophysics Data System (ADS)

Compounds [(?-H)Os 3(CO) 10(?-NH 2)] and a new polymorphic form of [(?-H)Os 3(CO) 10(?-SH)] were obtained from the reaction of [H 2Os 3(CO) 10] with 1,3,5-N,N,N,-trimethyl-triazinane and 1,3,5-trithiane respectively. The structures show the same geometry described for other doubly bridged triangular clusters. A comparison of these type of compounds show that the bridging group does not affect significantly the dihedral angle between Os 3 and Os 2X planes (X = NH 2, NRH, PRH, SbR 2, OH, OR, SH, SR, SeR, Cl and Br). The presence of a hydrogen atom on the bridge could favor a possible interaction between groups so the crystal packing is analyzed. Since intermolecular interactions could also be occurring in solution, reactions of [(?-H)Os 3(CO) 10(?-OH)] and [(?-H)Os 3(CO) 10(?-SH)] with proton sponge were carried out in order to determine if the OH or SH protons had acidic character and could react with a base. These results and other structural characteristics will be discussed.

Reyes-López, Ottmar R.; Leyva, Marco A.; Rosales-Hoz, María J.

2011-01-01

205

Stem cells: a promising source for vascular regenerative medicine.  

PubMed

The rising and diversity of many human vascular diseases pose urgent needs for the development of novel therapeutics. Stem cell therapy represents a challenge in the medicine of the twenty-first century, an area where tissue engineering and regenerative medicine gather to provide promising treatments for a wide variety of diseases. Indeed, with their extensive regeneration potential and functional multilineage differentiation capacity, stem cells are now highlighted as promising cell sources for regenerative medicine. Their multilineage differentiation involves environmental factors such as biochemical, extracellular matrix coating, oxygen tension, and mechanical forces. In this review, we will focus on human stem cell sources and their applications in vascular regeneration. We will also discuss the different strategies used for their differentiation into both mature and functional smooth muscle and endothelial cells. PMID:25167472

Rammal, Hassan; Harmouch, Chaza; Lataillade, Jean-Jacques; Laurent-Maquin, Dominique; Labrude, Pierre; Menu, Patrick; Kerdjoudj, Halima

2014-12-15

206

Spacecraft Radiator Freeze Protection Using a Regenerative Heat Exchanger  

NASA Technical Reports Server (NTRS)

An active thermal control system architecture has been modified to include a regenerative heat exchanger (regenerator) inboard of the radiator. Rather than using a radiator bypass valve a regenerative heat exchanger is placed inboard of the radiators. A regenerator cold side bypass valve is used to set the return temperature. During operation, the regenerator bypass flow is varied, mixing cold radiator return fluid and warm regenerator outlet fluid to maintain the system setpoint. At the lowest heat load for stable operation, the bypass flow is closed off, sending all of the flow through the regenerator. This lowers the radiator inlet temperature well below the system set-point while maintaining full flow through the radiators. By using a regenerator bypass flow control to maintain system setpoint, the required minimum heat load to avoid radiator freezing can be reduced by more than half compared to a radiator bypass system.

Ungar, Eugene K.; Schunk, Richard G.

2011-01-01

207

The Conduction of Heat through Cryogenic Regenerative Heat Exchangers  

NASA Astrophysics Data System (ADS)

The need for improved regenerative cryocooler efficiency may require the replacement of conventional matrices with ducts. The ducts can not be continuous in the direction of temperature gradient when using conventional materials to prevent unacceptable conduction losses. However, this discontinuity creates a complex geometry to model and determine conduction losses. Chesapeake Cryogenics, Inc. has designed, fabricated and tested an apparatus for measuring the heat conduction through regenerative heat exchangers implementing different matrices. Data is presented for stainless steel photo etched disk, phophorus-bronze embossed ribbon coils and screens made of both stainless steel and phosphorus-bronze. The heat conduction was measured with the regenerators evacuated and pressurized with helium gas. In this test apparatus, helium gas presence increased the heat leak significantly. A description of the test apparatus, instrumentation, experimental methods and data analysis are presented.

Superczynski, W. F.; Green, G. F.

2006-04-01

208

Seikan tunnel electric train propulsion -- Regenerative energy management  

SciTech Connect

The mission was to model the electric propulsion and regenerative energy requirements for the Kaikyo passenger train and the Kamotsusen freight train system currently operating between Tappikaitei and Yoshiokakaitei through the Seikan tunnel under the Pacific Ocean. The Seikan tunnel is over 54 km in length and connects Aomori on the main Japanese island of Honshu to the North island of Hokkaido. Further, over 24 km of the Seikan tunnel is 100 meters below the sea bed of the Tsugaru Strait which joins the Pacific with the Sea of Japan. While, the sea bed is 140 meters below the mean Pacific sea level, at the deepest point. Safety and energy conservation issues led to reliable regenerative energy recovery and braking systems.

Isshiki, Seita [Ashikaga Inst. of Tech., Tokyo (Japan); Wyczalek, F.A. [FW Lilly Inc., Bloomfield, Hills, MI (United States)

1997-12-31

209

Nanotechnologies and regenerative medical approaches for space and terrestrial medicine.  

PubMed

One purpose of the International Space Station (ISS) is to explore powerful new areas of biomedical science in microgravity. Recent advances in nanotechnology applied to medicine--what we now refer to as nano-medicine--and regenerative medicine have enormous untapped potential for future space and terrestrial medical applications. Novel means for drug delivery and nanoscale screening tools will one day benefit astronauts venturing to Mars and places beyond, while the space laboratory will foster advances in nanotechnologies for diagnostic and therapeutic tools to help our patients here on Earth. Herein we review a series of nanotechnologies and selected regenerative medical approaches and highlight key areas of ongoing and future investigation that will benefit both space and terrestrial medicine. These studies target significant areas of human disease such as osteoporosis, diabetes, radiation injury, and many others. PMID:23156089

Grattoni, Alessandro; Tasciotti, Ennio; Fine, Daniel; Fernandez-Moure, Joseph S; Sakamoto, Jason; Hu, Ye; Weiner, Bradley; Ferrari, Mauro; Parazynski, Scott

2012-11-01

210

Prostate . Author manuscript Inflammation in benign prostatic hyperplasia: a 282 patients'  

E-print Network

), including 282 patients treated by surgery for a complicated and/or symptomatic BPH. Inflammation score Analysis ; Middle Aged ; Prostatic Hyperplasia ; complications ; pathology ; Prostatitis ; complications

Boyer, Edmond

211

DC regenerative drive use for battery charge\\/discharge cycling  

Microsoft Academic Search

High-performance, re-chargeable batteries require carefully controlled charge\\/discharge cycling for cell formation and for acceptance testing. Standard battery charging circuits and resistive load banks have long been used for this application. This paper describes the use of a dc regenerative motor drive to efficiently provide the charge\\/discharge capability. An internal transformer reduces the supply line voltage to the maximum battery voltage,

J. Edward Jenkins Jr; Harry P. Jenkins; T. Piekarski; M. Waller

2007-01-01

212

A vapor injector-based novel regenerative organic Rankine cycle  

Microsoft Academic Search

A regenerative organic Rankine cycle (RORC) that uses a vapor injector as the regenerator is proposed. The physical process is theoretically described and the numerical analysis of the injector performance based on a one-dimensional model is also presented. The thermal performance of both the novel cycle and the basic ORC is calculated and compared by using R123 as the working fluid.

Rong-Ji Xu; Ya-Ling He

2011-01-01

213

Regenerative limestone slurry process for flue gas desulfurization  

Microsoft Academic Search

The feasibility of the regenerative limestone slurry process was demonstrated on a bench scale. CaCOâ and HâS were recovered from waste sludge from the limestone slurry flue gas desulfurization process. CaCOâ would be recycled to the scrubber. HâS would be converted to elemental sulfur in a Clause plant. At 950 to 980°C in the presence of coke or coal, 95%

Miriam S. Mozes

1978-01-01

214

Tissue engineering and regenerative medicine research perspectives for pediatric surgery  

Microsoft Academic Search

Tissue engineering and regenerative medicine research is being aggressively pursued in attempts to develop biological substitutes\\u000a to replace lost tissue or organs. Remarkable degrees of success have been achieved in the generation of a variety of tissues\\u000a and organs as a result of concerted contributions by multidisciplinary groups in the field of biotechnology. Engineering of\\u000a an organ is a complex

Amulya K. Saxena

2010-01-01

215

The Ovonic Regenerative Fuel Cell, A Fundamentally New Approach  

NSDL National Science Digital Library

This report introduces the Ovonic Regenerative fuel cell, which is a technology that "utilizes Ovonic metal hydride materials in place of traditional noble metal catalysts in the hydrogen fuel electrode." The paper goes into detail about how these fuel cells work and includes graphical representations of the processes involved. This paper was presented at the Hydrogen and Fuel Cells 2004 Conference and Trade Show in Toronto, Canada. This document may be downloaded in PDF file format.

Corrigan, D. A.; Ovshinsky, S. R.; Venkatesan, S.

2012-08-24

216

Unitized Regenerative Fuel Cell System Dryer-Humidifier Analytical Model Development  

NASA Technical Reports Server (NTRS)

A Unitized Regenerative Fuel Cell (URFC) Energy Storage System is being developed at the NASA Glenn Research Center. This URFC system is unique in that it uses regenerative gas dryers/humidifiers that are mounted on the surface of the gas storage tanks that act as the radiators for thermal control of the URFC system. As the gas storage tanks cool down during URFC charging the regenerative gas dryers/humidifiers dry the hydrogen and oxygen gases produced by electrolysis. As the gas storage tanks heat up during URFC discharging, the regenerative gas dryers/humidifiers humidify the hydrogen and oxygen gases used by fuel cell. An analytical model was developed to simulate the URFC system's regenerative gas dryers/humidifiers. The model is in the form of an EXCEL@ worksheet that allows the investigation of the regenerative gas dryers/humidifier performance as a function of time and position within the regenerative gas dryers/humidifiers, as well as other key system variables. Finite Element Analysis (FEA) modeling of the regenerative gas dryers/humidifier and gas storage tank wall was also done to analyze spatial temperature distribution within the regenerative gas dryers/humidifiers and the localized tank wall. Test results obtained from the testing of the regenerative gas dryers/humidifiers in a thermal vacuum environment were used to corroborate the analyses.

Burke, Kenneth A.; Jakupca, Ian

2003-01-01

217

Muscle stem cells in developmental and regenerative myogenesis  

PubMed Central

Purpose of review Skeletal muscle development serves as a paradigm for cell lineage specification and cell differentiation. Adult skeletal muscle has high regenerative capacity, with satellite cells the primary source of this capability. This review describes recent findings on developmental and adult myogenesis with emphasis on emerging distinctions between various muscle groups and stages of myogenesis. Recent findings Muscle progenitors of the body are derived from multipotent cells of the dermomyotome and express the transcription factors Pax3 and Pax7. These cells self-renew or induce expression of muscle regulatory factors (MRFs) and differentiate. The roles of Pax3+, Pax7+ and specific MRF+ progenitor populations in trunk and limb myogenesis have been identified through cell ablation in the mouse. Various head muscles and associated satellite cells have differing developmental origins, and rely on distinct combinations of transcriptional regulators, than trunk and limb muscles. Several genetic and sorting protocols demonstrate that satellite cells are heterogeneous with some possessing stem cell properties; the relative roles of lineage and niche in these properties are being explored. While cellular mechanisms of developmental, post-natal and adult regenerative myogenesis are thought to be similar, recent studies reveal distinct genetic requirements for embryonic, fetal, post-natal and adult regenerative myogenesis. Summary Genetic determinants of formation or repair of various muscles during different stages myogenesis are unexpectedly diverse. Future studies should illuminate these differences, as well as mechanisms that underlie stem cell properties of satellite cells. PMID:20098319

Kang, Jong-Sun; Krauss, Robert S.

2010-01-01

218

Leptin Effects on the Regenerative Capacity of Human Periodontal Cells  

PubMed Central

Obesity is increasing throughout the globe and characterized by excess adipose tissue, which represents a complex endocrine organ. Adipose tissue secrets bioactive molecules called adipokines, which act at endocrine, paracrine, and autocrine levels. Obesity has recently been shown to be associated with periodontitis, a disease characterized by the irreversible destruction of the tooth-supporting tissues, that is, periodontium, and also with compromised periodontal healing. Although the underlying mechanisms for these associations are not clear yet, increased levels of proinflammatory adipokines, such as leptin, as found in obese individuals, might be a critical pathomechanistic link. The objective of this study was to examine the impact of leptin on the regenerative capacity of human periodontal ligament (PDL) cells and also to study the local leptin production by these cells. Leptin caused a significant downregulation of growth (TGF?1, and VEGFA) and transcription (RUNX2) factors as well as matrix molecules (collagen, and periostin) and inhibited SMAD signaling under regenerative conditions. Moreover, the local expression of leptin and its full-length receptor was significantly downregulated by inflammatory, microbial, and biomechanical signals. This study demonstrates that the hormone leptin negatively interferes with the regenerative capacity of PDL cells, suggesting leptin as a pathomechanistic link between obesity and compromised periodontal healing. PMID:25136363

Nokhbehsaim, Marjan; Keser, Sema; Jäger, Andreas; Jepsen, Søren; Bourauel, Christoph

2014-01-01

219

Marching towards regenerative cardiac therapy with human pluripotent stem cells.  

PubMed

Damage in cardiac tissues from ischemia or other pathological conditions leads to heart failure; and cell loss or dysfunction in pacemaker tissues due to congenital heart defects, aging, and acquired diseases can cause severe arrhythmias. The promise of successful therapies with stem cells to treat these conditions has remained elusive to the scientific community. However, recent advances in this field have opened new opportunities for regenerative cardiac therapy. Transplantation of cardiomyocytes derived from human pluripotent stem cells has the potential to alleviate heart disease. Since the initial derivation of human embryonic stem cells, significant progress has been made in the generation and characterization of enriched cardiomyocytes and the demonstration of the ability of these cardiomyocytes to survive, integrate, and function in animal models. The scope of therapeutic potential from pluripotent stem cell-derived cardiomyocytes has been further expanded with the invention of induced pluripotent stem cells, which can be induced to generate functional cardiomyocytes for regenerative cardiac therapy in a patient specific manner. The reprogramming technology has also inspired the recent discovery of direct conversion of fibroblasts into cardiomyocyte-like cells, which may allow endogenous cardiac repair. Regenerative cardiac therapy with human pluripotent stem cells is now moving closer to clinic testing. PMID:23819949

Maher, Kevin O; Xu, Chunhui

2013-06-01

220

Potential regenerative treatment strategies for intervertebral disc degeneration in dogs  

PubMed Central

Pain due to spontaneous intervertebral disc (IVD) disease is common in dogs. In chondrodystrophic (CD) dogs, IVD disease typically develops in the cervical or thoracolumbar spine at about 3–7 years of age, whereas in non-chondrodystrophic (NCD) dogs, it usually develops in the caudal cervical or lumbosacral spine at about 6–8 years of age. IVD degeneration is characterized by changes in the biochemical composition and mechanical integrity of the IVD. In the degenerated IVD, the content of glycosaminoglycan (GAG, a proteoglycan side chain) decreases and that of denatured collagen increases. Dehydration leads to tearing of the annulus fibrosus (AF) and/or disc herniation, which is clinically characterized by pain and/or neurological signs. Current treatments (physiotherapy, anti-inflammatory/analgesic medication, surgery) for IVD disease may resolve neurological deficits and reduce pain (although in many cases insufficient), but do not lead to repair of the degenerated disc. For this reason, there is interest in new regenerative therapies that can repair the degenerated disc matrix, resulting in restoration of the biomechanical function of the IVD. CD dogs are considered a suitable animal model for human IVD degeneration because of their spontaneous IVD degeneration, and therefore studies investigating cell-, growth factor-, and/or gene therapy-based regenerative therapies with this model provide information relevant to both human and canine patients. The aim of this article is to review potential regenerative treatment strategies for canine IVD degeneration, with specific emphasis on cell-based strategies. PMID:24387033

2014-01-01

221

Adenomyomatous hyperplasia of the gallbladder with perineural invasion: revisited.  

PubMed

We report 9 examples of segmental adenomyomatous hyperplasia of the gallbladder with perineural invasion. Five patients were women and 4 men. Their ages ranged from 49 to 81 years (mean age 64 y). Eight patients had gallbladder calculi. The original pathologic diagnosis of adenocarcinoma was made in 5 patients and of "adenoma malignum" in one. Six patients are disease-free for 2 to 11 years following cholecystectomy, 1 patient died of unrelated causes and 2 were lost to follow-up. Histologically 2 types of adenomyomatous hyperplasia were recognized. The first one characterized by numerous Rokitansky-Aschoff sinuses (RASs) was accompanied by smooth muscle hyperplasia and an expanded subserosal layer containing numerous nerve trunks (6 cases). The second type was characterized by an extensively fibrotic gallbladder wall with numerous RASs but with few or no smooth muscle bundles and an expanded subserosal layer containing abundant nerve-trunks (3 cases). Perineural (7 cases) and intraneural invasion (2 cases) was identified only in the subserosal layer. The lack of p53 reactivity and the very low MIB-1-labeling index provide additional support to the non-neoplastic nature of the lesion. The pseudoinvasive pattern of the RASs, reactive epithelial atypia, and the perineural and intraneural invasion probably contributed to the erroneous diagnosis of adenocarcinoma or "adenoma malignum." The mechanism by which the epithelial structures "invaded" the perineural spaces and the nerves is unclear. We favor the hypothesis that the migration of the benign glandlike structures into the nerves is related to the production of chemotactic factors or signaling substances and the activation of cell receptors. PMID:17895763

Albores-Saavedra, Jorge; Keenportz, Brent; Bejarano, Pablo A; Alexander, Alan A Z; Henson, Donald E

2007-10-01

222

Pancreatic fibrosis associated with age and ductal papillary hyperplasia.  

PubMed

Little is known about the frequency, type and pathogenesis of fibrotic changes that may occur in the pancreas of persons without any clinically apparent or macroscopically visible pancreatic disease. We screened pancreas specimens for the presence and pattern of fibrosis, determined the relationship between fibrosis, age, and duct lesions, and studied the fibrogenic mechanisms. In 89 postmortem specimens from persons without any known pancreatic disease (age range 20-86 years), fibrosis was recorded and graded and the patients were divided into two age classes (younger or older than 60 years). In addition, we analyzed the association between ductal papillary hyperplasia [i.e., pancreatic intraepithelial neoplasia type 1B (PanIN-1B)] and fibrotic foci in the pancreatic tissue to determine the potential impact of obliterating duct lesions on pancreatic fibrosis. Finally, we studied the occurrence in the pancreas of myofibroblasts, identified on the basis of their alpha-SMA and desmin positivity, and determined their relationship to the fibrotic foci. Thirty-eight (44%) of 89 pancreata showed scattered foci of lobular fibrosis affecting peripheral lobuli. Fibrotic changes were significantly more common in individuals older than 60 years. Fibrotic foci were commonly associated (p<0.05) with ductal papillary hyperplasia in ducts draining fibrotic lobuli. Myofibroblasts were detected in the fibrotic foci. The "normal" pancreas develops a specific type of focally accentuated fibrosis that is highly age related. This patchy lobular fibrosis in the elderly (PLFE) was closely associated with PanIN-1B lesions in the ducts, suggesting that the narrowing of a duct due to papillary hyperplasia of the epithelium may hamper secretion and cause fibrosis of the drained lobule. The presence of myofibroblasts in association with the fibrotic foci indicates an ongoing fibrogenic process. PMID:16021508

Detlefsen, Sönke; Sipos, Bence; Feyerabend, Bernd; Klöppel, Günter

2005-11-01

223

Pituitary hyperplasia: a complication of the pseudomalabsorption of thyroxine  

PubMed Central

Objective “The pseudomalabsorption of thyroxine” has been used to describe patients with hypothyroidism who fail to comply with their treatment. We describe a unique case of a 32-year-old with hypothyroidism who developed pituitary hyperplasia and hyperprolactinemia secondary to the pseudomalabsorption of thyroxine. Investigations and treatment After baseline thyroid-function tests were performed, the patient was administered levothyroxine 0.5 mg under the supervision of a registered nurse. Thyroid function testing was repeated at 30, 60, 120, and 180 minutes. Arrangements were made for further daily supervised loading of levothyroxine 0.1 mg. Results With the administration of 0.5 mg levothyroxine, free thyroxine levels increased by 120 minutes, and with daily supervised dosing of 0.1 mg there was normalization of the thyroid hormone levels and a reduction of thyroid-stimulating hormone levels. Maintenance of thyroid-stimulating hormone < 15 mU/L for 2 weeks led to a reduction in prolactin levels and regression in the size of the pituitary on magnetic resonance imaging. Conclusion If left untreated, these patients face significant morbidity and are at risk of developing pituitary hyperplasia, complications from an increase in pituitary size, hyperprolactinemia, and potentially myxedema coma. Recognizing pituitary hyperplasia and hyperprolactinemia as a complication from the pseudomalabsorption of levothyroxine may prevent the potential of a misdiagnosis of a prolactinoma leading to unnecessary investigations and inappropriate treatment. Patient awareness of this serious complication and the rapid, demonstrable resolution with adequate thyroid hormone replacement may provide motivation to comply with supervised dosing of levothyroxine. It has also been suggested that supervised treatment enables the individual to maintain their patient status, which may be in part the motivation behind this disorder. PMID:23766656

Doyle, Mary-Anne; Lochnan, Heather A

2013-01-01

224

Morphometric evaluation of vascularization of hepatic focal nodular hyperplasia.  

PubMed

Comparative morphometric evaluation of the quantitative characteristics of vessels in hepatic focal nodular hyperplasia tissue was carried out on preparations stained with hematoxylin and eosin and by immunohistochemical detection of CD34 and CD105. Analysis of histological preparations stained with hematoxylin and eosin allowed the most ample characterization. Immunohistochemical detection of CD34 promoted better visualization of endotheliocytes, but just some sinusoids in the preparations were labeled. Expression of CD105 visualized the active endothelial cells and hence, helped to evaluate neoangiogenesis. PMID:24319765

Shchyogolev, A I; Tumanova, U N; Dubova, E A

2013-12-01

225

Paradigm lost: a perspective on the design and interpretation of regenerative endodontic research.  

PubMed

Regenerative endodontic procedures are rapidly gaining the attention of clinicians and investigators alike. However, it is often challenging to understand various regenerative studies and to interpret their results. The present review addresses this problem by focusing on recent strategies for developing standardized clinical protocols, understanding the full spectrum of clinical and translational research and its relationship to selection of proper outcome measures, as well as reviewing the fundamental role of paradigms in designing and interpreting regenerative studies. PMID:24698697

Hargreaves, Kenneth M; Diogenes, Anibal; Teixeira, Fabricio B

2014-04-01

226

Diode-pumped regenerative Yb:SrF2 amplifier Sandrine Ricaud1,3,*  

E-print Network

SrF2, SrF2-CaF2, SrF2-BaF2, and YLF," in Advanced Solid-State Photonics, OSA Technical Digest SeriesDiode-pumped regenerative Yb:SrF2 amplifier Sandrine Ricaud1,3,* , Patrick Georges1 , Patrice Camy2 we believe to be the first Yb:SrF2 regenerative femtosecond amplifier. The regenerative amplifier

Boyer, Edmond

227

Eccrine Squamous Syringometaplasia and Syringomatous Hyperplasia in Association with Linear Scleroderma  

Microsoft Academic Search

It is now well recognized that syringomatous hyperplasia with squamous syringometaplasia is a type of pseudoepitheliomatous hyperplasia responding to a variety of stimuli. We report a case of linear scleroderma with this process. Histopathology of the lesion showed numerous solid and cystic epithelial structures with squamous metaplasia within typical sclerodermatous skin lesions. Although the pathogenesis of the process remains unclear,

Hiroyuki Sakai; Katsuhiko Satoh; Akira Manabe; Hiroshi Nakane; Akemi Ishida-Yamamoto; Hajime Iizuka

2002-01-01

228

Maspin expression, subcellular localization and clinicopathological correlation in endometrial hyperplasia and endometrial adenocarcinoma.  

PubMed

Maspin expression in endometrial hyperplasia and endometrial endometrioid adenocarcinomas was assessed and its correlation with p53 and Ki67 expressions and clinical outcome, as well as its potential to distinguish typical from atypical endometrial hyperplasia, were assessed in this study. Histological sections from 114 cases of endometrial endometrioid adenocarcinoma, 75 cases of endometrial hyperplasia (typical and atypical), and 23 normal endometrial tissue samples were examined. The most representative hematoxylin-eosin slides were selected and 2-3 micron-thick sections were cut for immunohistochemical staining with maspin, p53, and Ki67 antibodies. While there was no maspin expression in normal endometrial cells, it was present in 14.5% of the patients with endometrial hyperplasia without atypia. Staining for maspin was positive in atypical hyperplasia and endometrial adenocarcinoma in, respectively, 45% and 49.1% of the cases studied. No statistically significant correlations were found between maspin and Ki-67 antibodies or p53 expression. Our findings showed that maspin expression, which generally correlates with a less aggressive behavior, is significantly higher in atypical hyperplasia and in endometrial endometrioid adenocarcinoma. Maspin positivity in endometrial hyperplasia could be used to identify pseudo-atypical hyperplasia and could be considered a potentially useful prognostic parameter in those cases in which adenocarcinomas are well differentiated. PMID:24346847

Blandamura, Stella; Alessandrini, Lara; Saccardi, Carlo; Giacomelli, Luciano; Fabris, Alberta; Borghero, Angela; Litta, Pietro

2014-06-01

229

Angiolymphoid hyperplasia with eosinophilia: a previously unreported complication of ear piercing.  

PubMed

Angiolymphoid hyperplasia with eosinophilia is a rare, benign vascular lesion characterized by discrete, painful papules. Although the exact etiology is unknown, trauma precedes many cases. We present a case of angiolymphoid hyperplasia with eosinophilia in the earlobes of a 15-year-old girl after ear piercing. PMID:25424213

Okman, Jonathan S; Bhatti, Tricia R; Jackson, Oksana A; Rubin, Adam I

2014-01-01

230

Focal nodular hyperplasia in association with spontaneous intrahepatic portosystemic venous shunt.  

PubMed

We report a case of focal nodular hyperplasia in an adolescent with a spontaneous intrahepatic portosystemic venous shunt. Diagnosis was established by duplex and color Doppler ultrasound, computed tomography, magnetic resonance imaging, and histology. This association further supports the hypothesis that focal nodular hyperplasia is a response to a preexisting vascular abnormality. PMID:1551514

Lalonde, L; Van Beers, B; Trigaux, J P; Delos, M; Melange, M; Pringot, J

1992-01-01

231

Focal nodular hyperplasia in association with spontaneous intrahepatic portosystemic venous shunt  

Microsoft Academic Search

We report a case of focal nodular hyperplasia in an adolescent with a spontaneous intrahepatic portosystemic venous shunt. Diagnosis was established by duplex and color Doppler ultrasound, computed tomography, magnetic resonance imaging, and histology. This association further supports the hypothesis that focal nodular hyperplasia is a response to a preexisting vascular abnormality.

Lucie Lalonde; Bernard Van Beers; Jean-Paul Trigaux; Monique Delos; Michel Melange; Jacques Pringot

1992-01-01

232

A New 3-D Automated Computational Method to Evaluate In-Stent Neointimal Hyperplasia in  

E-print Network

A New 3-D Automated Computational Method to Evaluate In-Stent Neointimal Hyperplasia in In gozdeunal@sabanciuniv.edu 2 St Maria hospital, Halle and UZ Brussel, Belgium Abstract. Detection of stent (PCI) and quantification of in-stent neointimal hyperplasia (NIH) are important. In this paper, we

Yanikoglu, Berrin

233

Integration and dynamics of a renewable regenerative hydrogen fuel cell system.  

E-print Network

??This thesis explores the integration and dynamics of residential scale renewable-regenerative energy systems which employ hydrogen for energy buffering. The development of the Integrated Renewable… (more)

Bergen, Alvin P

2008-01-01

234

Lymphoid hyperplasia and lymphoma in KSHV K1 transgenic mice.  

PubMed

Growing evidence supports the involvement of human herpervirus 8, Kaposi's sarcoma associated herpesvirus (KSHV), in the pathology of primary effusion lymphoma, multicentric Castleman's disease, and Kaposi's sarcoma, but the exact mechanism of KSHV contribution to the oncogenic process remains elusive. We studied transgenic mice expressing the ORF K1 of KSHV, whose position in the KSHV genome corresponds to known lymphoproliferative genes of other herpesviruses. K1 protein was previously shown to contain a constitutively active ITAM domain, involved in activation of Akt and pro-survival signaling, and to inhibit Fas-mediated apoptosis by interfering with binding of FasL. All this pointed to a possible role of K1 in the pathogenesis of KSHV-associated cancers. K1 transgenic mice (80-90%) developed lymphoid hyperplasia and splenomegaly at 8 and 10 months of age, 25% had confirmed diagnosis of lymphoma, and 50% developed abdominal and/or hepatic tumors by 18 months of age. Histological examination showed loss of splenic architecture and increased cellularity. Lymph nodes showed disrupted architecture with effaced follicles and other pathological changes, including signs of angiofollicular lymphoid hyperplasia. One of the livers showed signs of angiosarcoma. In summary, our histology results revealed pathological changes in K1 transgenic mice similar to lymphoma, Castleman's disease, and angiosarcoma, suggesting that K1 may contribute to the development of KSHV-associated cancers. PMID:25301266

Berkova, Zuzana; Wang, Shu; Sehgal, Lalit; Patel, Keyur Pravinchandra; Prakash, Om; Samaniego, Felipe

2014-10-10

235

Integration of regenerative shock absorber into vehicle electric system  

NASA Astrophysics Data System (ADS)

Regenerative/Energy harvesting shock absorbers have a great potential to increase fuel efficiency and provide suspension damping simultaneously. In recent years there's intensive work on this topic, but most researches focus on electricity extraction from vibration and harvesting efficiency improvement. The integration of electricity generated from regenerative shock absorbers into vehicle electric system, which is very important to realize the fuel efficiency benefit, has not been investigated. This paper is to study and demonstrate the integration of regenerative shock absorber with vehicle alternator, battery and in-vehicle electrical load together. In the presented system, the shock absorber is excited by a shaker and it converts kinetic energy into electricity. The harvested electricity flows into a DC/DC converter which realizes two functions: controlling the shock absorber's damping and regulating the output voltage. The damping is tuned by controlling shock absorber's output current, which is also the input current of DC/DC converter. By adjusting the duty cycles of switches in the converter, its input impedance together with input current can be adjusted according to dynamic damping requirements. An automotive lead-acid battery is charged by the DC/DC converter's output. To simulate the working condition of combustion engine, an AC motor is used to drive a truck alternator, which also charges the battery. Power resistors are used as battery's electrical load to simulate in-vehicle electrical devices. Experimental results show that the proposed integration strategy can effectively utilize the harvested electricity and power consumption of the AC motor is decreased accordingly. This proves the combustion engine's load reduction and fuel efficiency improvement.

Zhang, Chongxiao; Li, Peng; Xing, Shaoxu; Kim, Junyoung; Yu, Liangyao; Zuo, Lei

2014-03-01

236

Cell/tissue processing information system for regenerative medicine.  

PubMed

When conducting clinical studies of regenerative medicine, compliance to good manufacturing practice (GMP) is mandatory, and thus much time is needed for manufacturing and quality management. It is therefore desired to introduce the manufacturing execution system (MES), which is being adopted by factories manufacturing pharmaceutical products. Meanwhile, in manufacturing human cell/tissue processing autologous products, it is necessary to protect patients' personal information, prevent patients from being identified and obtain information for cell/tissue identification. We therefore considered it difficult to adopt conventional MES to regenerative medicine-related clinical trials, and so developed novel software for production/quality management to be used in cell-processing centres (CPCs), conforming to GMP. Since this system satisfies the requirements of regulations in Japan and the USA for electronic records and electronic signatures (ER/ES), the use of ER/ES has been allowed, and the risk of contamination resulting from the use of recording paper has been eliminated, thanks to paperless operations within the CPC. Moreover, to reduce the risk of mix-up and cross-contamination due to contact during production, we developed a touchless input device with built-in radio frequency identification (RFID) reader-writer devices and optical sensors. The use of this system reduced the time to prepare and issue manufacturing instructions by 50% or more, compared to the conventional handwritten system. The system contributes to producing more large-scale production and to reducing production costs for cell and tissue products in regenerative medicine. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24700532

Iwayama, Daisuke; Yamato, Masayuki; Tsubokura, Tetsuya; Takahashi, Minoru; Okano, Teruo

2014-04-01

237

Skin Wound Healing and Scarring: Fetal Wounds and Regenerative Restitution  

PubMed Central

The adverse physiological and psychological effects of scars formation after healing of wounds are broad and a major medical problem for patients. In utero, fetal wounds heal in a regenerative manner, though the mechanisms are unknown. Differences in fetal scarless regeneration and adult repair can provide key insight into reduction of scarring therapy. Understanding the cellular and extracellular matrix alterations in excessive adult scarring in comparison to fetal scarless healing may have important implications. Herein, we propose that matrix can be controlled via cellular therapy to resemble a fetal-like matrix that will result in reduced scarring. PMID:24203921

Yates, Cecelia C.; Hebda, Patricia; Wells, Alan

2014-01-01

238

An alexandrite regenerative amplifier for water vapor and temperature measurements  

NASA Technical Reports Server (NTRS)

The Differential Absorption Lidar (DIAL) technique is a powerful method for determining meteorological parameters, but it requires high quality of the laser source: high energy, very narrow bandwidth, high wavelength stability, and spectral purity. Although many efforts have been made to improve the lasers in view of these aspects, a satisfactory solution has not been demonstrated up to now. We describe a regenerative amplifier, using a Ti:sapphire laser as master oscillator and an alexandrite laser as slave amplifier, which is expected to meet the requirements for water vapor concentration and temperature measurements.

Thro, P.-Y.; Boesenberg, J.; Wulfmeyer, V.

1992-01-01

239

Propellant feed system of a regeneratively cooled scramjet  

SciTech Connect

An expander cycle for an airframe-integrated hydrogen-fueled scramjet is analyzed to study regenerative cooling characteristics and overall specific impulse. Below Mach 10, the specific impulse and thrust coincide with the reference values. At Mach numbers above 10, a reduction of the specific impulse occurs due to the coolant flow rate requirement, which is accompanied by an increase of thrust. It is shown that the thrust may be increased by injecting excess fuel into the combustor to compensate for the decrease of the specific impulse. 9 refs.

Kanda, Takeshi; Masuya, Goro; Wakamatsu, Yoshio (National Aerospace Laboratory, Kakuda (Japan))

1991-04-01

240

New approach in dynamics of regenerative chatter research of turning  

NASA Astrophysics Data System (ADS)

In this paper, regenerative chatter phenomena in a turning process is discussed from impulsive dynamical point of view. By introducing the instantaneous pulse when vibration occurs and the vibratory condition set, we optimize the models and present a certain kind of second-order impulsive differential systems, which is a specific discontinuous dynamical system. Then we search for the general results of the nonoccurrence of chatter phenomena by discussing the number of the vibration pulse times, utilizing the method of flow theory in discontinuous systems and transversal property at the boundary. Our results give a convenient way to estimate the available parameters to keep the turning process stable.

Fu, Xilin; Zheng, Shasha

2014-11-01

241

Regeneratively cooled rocket engine for space storable propellants  

NASA Technical Reports Server (NTRS)

Analysis, design, fabrication, and test efforts were performed for the existing OF2/B2H6 regeneratively cooled lK (4448 N) thrust chamber to illustrate simultaneous B2H6 fuel and OF2 oxidizer cooling and to provide results for a gaseous propellant condition injected into the combustion chamber. Data derived from performance, thermal and flow measurements confirmed predictions derived from previous test work and from concurrent analytical study. Development data derived from the experimental study were indicated to be sufficient to develop a preflight thrust chamber demonstrator prototype for future space mission objectives.

Wagner, W. R.

1973-01-01

242

Regenerative Medicine for Epilepsy: From Basic Research to Clinical Application  

PubMed Central

Epilepsy is a chronic neurological disorder, which presents with various forms of seizures. Traditional treatments, including medication using antiepileptic drugs, remain the treatment of choice for epilepsy. Recent development in surgical techniques and approaches has improved treatment outcomes. However, several epileptic patients still suffer from intractable seizures despite the advent of the multimodality of therapies. In this article, we initially provide an overview of clinical presentation of epilepsy then describe clinically relevant animal models of epilepsy. Subsequently, we discuss the concepts of regenerative medicine including cell therapy, neuroprotective agents, and electrical stimulation, which are reviewed within the context of our data. PMID:24287913

Yasuhara, Takao; Agari, Takashi; Kameda, Masahiro; Kondo, Akihiko; Kuramoto, Satoshi; Jing, Meng; Sasaki, Tatsuya; Toyoshima, Atsuhiko; Sasada, Susumu; Sato, Kenichiro; Shinko, Aiko; Wakamori, Takaaki; Okuma, Yu; Miyoshi, Yasuyuki; Tajiri, Naoki; Borlongan, Cesario V.; Date, Isao

2013-01-01

243

Precision manufacturing for clinical-quality regenerative medicines.  

PubMed

Innovations in engineering applied to healthcare make a significant difference to people's lives. Market growth is guaranteed by demographics. Regulation and requirements for good manufacturing practice-extreme levels of repeatability and reliability-demand high-precision process and measurement solutions. Emerging technologies using living biological materials add complexity. This paper presents some results of work demonstrating the precision automated manufacture of living materials, particularly the expansion of populations of human stem cells for therapeutic use as regenerative medicines. The paper also describes quality engineering techniques for precision process design and improvement, and identifies the requirements for manufacturing technology and measurement systems evolution for such therapies. PMID:22802496

Williams, David J; Thomas, Robert J; Hourd, Paul C; Chandra, Amit; Ratcliffe, Elizabeth; Liu, Yang; Rayment, Erin A; Archer, J Richard

2012-08-28

244

Gaussian-only regenerative stations cannot act as quantum repeaters  

NASA Astrophysics Data System (ADS)

Higher transmission loss diminishes the performance of optical communication—be it the rate at which classical or quantum data can be sent reliably, or the secure key generation rate of quantum key distribution (QKD). Loss compounds with distance—exponentially in an optical fiber, and inverse square with distance for a free-space channel. In order to boost classical communication rates over long distances, it is customary to introduce regenerative relays at intermediate points along the channel. It is therefore natural to speculate whether untended regenerative stations, such as phase-insensitive or phase-sensitive optical amplifiers, could serve as repeaters for long-distance QKD. The primary result of this paper rules out all bosonic Gaussian channels to be useful as QKD repeaters, which include phase-insensitive and phase-sensitive amplifiers as special cases, for any QKD protocol. We also delineate the conditions under which a Gaussian relay renders a lossy channel entanglement breaking, which in turn makes the channel useless for QKD.

Namiki, Ryo; Gittsovich, Oleg; Guha, Saikat; Lütkenhaus, Norbert

2014-12-01

245

Feasibility study of a simple unitized regenerative fuel cell  

NASA Astrophysics Data System (ADS)

Conventional fuel cells use hydrogen and oxygen as the fuel and oxidant, respectively. Hydrogen and oxygen can be produced through electrolysis of water in an electrochemical cell. A simple unitized regenerative fuel cell (URFC), by combining an electrolyzer and a fuel cell, is constructed to check the feasibility of such a device. In the first cycle, hydrogen and oxygen gases are generated from water containing NaHCO 3 when a given dc voltage is applied across Ni-Co/stainless steel electrodes. A solar photovoltaic cell is also used to provide the power. The generated gases are trapped between their respective electrodes and nylon mesh. In the second cycle, the hydrogen and oxygen gases are used in the same electrochemical cell (fuel cell) to produce electricity under a specific load. The current density and voltage are measured by varying different parameters, e.g., time of electrolysis, magnitude of voltage applied, and electrolyte concentration. An open-circuit voltage (OCV) of 1.3 V is obtained from two regenerative fuel cells in series with a total active electrode area of 300 cm 2. A current density of about 0.5 mA cm -2 is generated using 0.5N NaHCO 3 when 4.5 V is applied for 25 min. A maximum power of 36.5 mW is obtained at 0.21 mA cm -2.

Verma, A.; Basu, S.

246

Johnson Space Center's regenerative life support systems test bed  

NASA Technical Reports Server (NTRS)

The Regenerative Life Support System (RLSS) Test Bed at NASA's Johnson Space Center is an atmospherically closed, controlled environment facility for the evaluation of regenerative life support systems using higher plants in conjunction with physicochemical life support systems. When completed, the facility will be comprised of two large scale plant growth chambers, each with approximately 10 m(exp 2) growing area. One of the two chambers, the Variable Pressure Growth Chamber (VPGC), will be capable of operating at lower atmospheric pressures to evaluate a range of environments that may be used in Lunar or Martian habitats; the other chamber, the Ambient Pressure Growth Chamber (APGC) will operate at ambient atmospheric pressure. The root zone in each chamber will be configurable for hydroponic or solid state media systems. Research will focus on: (1) in situ resource utilization for CELSS systems, in which simulated lunar soils will be used in selected crop growth studies; (2) integration of biological and physicochemical air and water revitalization systems; (3) effect of atmospheric pressure on system performance; and (4) monitoring and control strategies.

Henninger, Donald L.; Tri, Terry O.; Barta, Daniel J.; Stahl, Randal S.

1991-01-01

247

Johnson Space Center's Regenerative Life Support Systems Test Bed  

NASA Astrophysics Data System (ADS)

The Regenerative Life Support Systems (RLSS) Test Bed at NASA's Johnson Space Center is an atmospherically closed, controlled environment facility for human testing of regenerative life support systems using higher plants in conjunction with physicochemical life support systems. The facility supports NASA's Advanced Life Support (ALS) Program. The facility is comprised of two large scale plant growth chambers, each with approximately 11 m^2 growing area. The root zone in each chamber is configurable for hydroponic or solid media plant culture systems. One of the two chambers, the Variable Pressure Growth Chamber (VPGC), is capable of operating at lower atmospheric pressures to evaluate a range of environments that may be used in a planetary surface habitat; the other chamber, the Ambient Pressure Growth Chamber (APGC) operates at ambient atmospheric pressure. The air lock of the VPGC is currently being outfitted for short duration (1 to 15 day) human habitation at ambient pressures. Testing with and without human subjects will focus on 1) integration of biological and physicochemical air and water revitalization systems; 2) effect of atmospheric pressure on system performance; 3) planetary resource utilization for ALS systems, in which solid substrates (simulated planetary soils or manufactured soils) are used in selected crop growth studies; 4) environmental microbiology and toxicology; 5) monitoring and control strategies; and 6) plant growth systems design. Included are descriptions of the overall design of the test facility, including discussions of the atmospheric conditioning, thermal control, lighting, and nutrient delivery systems.

Barta, D. J.; Henninger, D. L.

1996-01-01

248

Bioluminescence regenerative cycle (BRC) system for nucleic acid quantification assays  

NASA Astrophysics Data System (ADS)

A new label-free methodology for nucleic acid quantification has been developed where the number of pyrophosphate molecules (PPi) released during polymerization of the target nucleic acid is counted and correlated to DNA copy number. The technique uses the enzymatic complex of ATP-sulfurylase and firefly luciferase to generate photons from PPi. An enzymatic unity gain positive feedback is also implemented to regenerate the photon generation process and compensate any decay in light intensity by self regulation. Due to this positive feedback, the total number of photons generated by the bioluminescence regenerative cycle (BRC) can potentially be orders of magnitude higher than typical chemiluminescent processes. A system level kinetic model that incorporates the effects of contaminations and detector noise was used to show that the photon generation process is in fact steady and also proportional to the nucleic acid quantity. Here we show that BRC is capable of detecting quantities of DNA as low as 1 amol (10-18 mole) in 40?lit aqueous solutions, and this enzymatic assay has a controllable dynamic range of 5 orders of magnitude. The sensitivity of this technology, due to the excess number of photons generated by the regenerative cycle, is not constrained by detector performance, but rather by possible PPi or ATP (adenosine triphosphate) contamination, or background bioluminescence of the enzymatic complex.

Hassibi, Arjang; Lee, Thomas H.; Davis, Ronald W.; Pourmand, Nader

2003-07-01

249

Johnson Space Center's Regenerative Life Support Systems Test Bed  

NASA Technical Reports Server (NTRS)

The Regenerative Life Support Systems (RLSS) Test Bed at NASA's Johnson Space Center is an atmospherically closed, controlled environment facility for human testing of regenerative life support systems using higher plants in conjunction with physicochemical life support systems. The facility supports NASA's Advanced Life Support (ALS) Program. The facility is comprised of two large scale plant growth chambers, each with approximately 11 m2 growing area. The root zone in each chamber is configurable for hydroponic or solid media plant culture systems. One of the two chambers, the Variable Pressure Growth Chamber (VPGC), is capable of operating at lower atmospheric pressures to evaluate a range of environments that may be used in a planetary surface habitat; the other chamber, the Ambient Pressure Growth Chamber (APGC) operates at ambient atmospheric pressure. The air lock of the VPGC is currently being outfitted for short duration (1 to 15 day) human habitation at ambient pressures. Testing with and without human subjects will focus on 1) integration of biological and physicochemical air and water revitalization systems; 2) effect of atmospheric pressure on system performance; 3) planetary resource utilization for ALS systems, in which solid substrates (simulated planetary soils or manufactured soils) are used in selected crop growth studies; 4) environmental microbiology and toxicology; 5) monitoring and control strategies; and 6) plant growth systems design. Included are descriptions of the overall design of the test facility, including discussions of the atmospheric conditioning, thermal control, lighting, and nutrient delivery systems.

Barta, D. J.; Henninger, D. L.

1996-01-01

250

Endothelial Jagged-1 is necessary for homeostatic and regenerative hematopoiesis.  

PubMed

The bone marrow (BM) microenvironment is composed of multiple niche cells that, by producing paracrine factors, maintain and regenerate the hematopoietic stem cell (HSC) pool (Morrison and Spradling, 2008). We have previously demonstrated that endothelial cells support the proper regeneration of the hematopoietic system following myeloablation (Butler et al., 2010; Hooper et al., 2009; Kobayashi et al., 2010). Here, we demonstrate that expression of the angiocrine factor Jagged-1, supplied by the BM vascular niche, regulates homeostatic and regenerative hematopoiesis through a Notch-dependent mechanism. Conditional deletion of Jagged-1 in endothelial cells (Jag1((ECKO)) mice) results in a profound decrease in hematopoiesis and premature exhaustion of the adult HSC pool, whereas quantification and functional assays demonstrate that loss of Jagged-1 does not perturb vascular or mesenchymal compartments. Taken together, these data demonstrate that the instructive function of endothelial-specific Jagged-1 is required to support the self-renewal and regenerative capacity of HSCs in the adult BM vascular niche. PMID:24012753

Poulos, Michael G; Guo, Peipei; Kofler, Natalie M; Pinho, Sandra; Gutkin, Michael C; Tikhonova, Anastasia; Aifantis, Iannis; Frenette, Paul S; Kitajewski, Jan; Rafii, Shahin; Butler, Jason M

2013-09-12

251

Unitized Regenerative Fuel Cell System Gas Storage-Radiator Development  

NASA Technical Reports Server (NTRS)

High-energy-density regenerative fuel cell systems that are used for energy storage require novel approaches to integrating components in order to preserve mass and volume. A lightweight unitized regenerative fuel cell (URFC) energy storage system concept is being developed at the NASA Glenn Research Center. This URFC system minimizes mass by using the surface area of the hydrogen and oxygen storage tanks as radiating heat surfaces for overall thermal control of the system. The waste heat generated by the URFC stack during charging and discharging is transferred from the cell stack to the surface of each tank by loop heat pipes, which are coiled around each tank and covered with a thin layer of thermally conductive carbon composite. The thin layer of carbon composite acts as a fin structure that spreads the heat away from the heat pipe and across the entire tank surface. Two different-sized commercial-grade composite tanks were constructed with integral heat pipes and tested in a thermal vacuum chamber to examine the feasibility of using the storage tanks as system radiators. The storage tank-radiators were subjected to different steady-state heat loads and varying heat load profiles. The surface emissivity and specific heat capacity of each tank were calculated. In the future, the results will be incorporated into a model that simulates the performance of similar radiators using lightweight, spacerated carbon composite tanks.

Burke, Kenneth A.; Jakupta, Ian

2005-01-01

252

AMR (Active Magnetic Regenerative) refrigeration for low temperature  

NASA Astrophysics Data System (ADS)

This paper reviews AMR (Active Magnetic Regenerative) refrigeration technology for low temperature applications that is a novel cooling method to expand the temperature span of magnetic refrigerator. The key component of the AMR system is a porous magnetic regenerator which allows a heat transfer medium (typically helium gas) to flow through it and therefore obviate intermittently operating an external heat switch. The AMR system alternatingly heats and cools the heat transfer medium by convection when the magneto-caloric effect is created under varying magnetic field. AMR may extend the temperature span for wider range than ADR (Adiabatic Demagnetization Refrigerator) at higher temperatures above 10 K because magneto-caloric effects are typically concentrated in a small temperature range in usual magnetic refrigerants. The regenerative concept theoretically enables each magnetic refrigerant to experience a pseudo-Carnot magnetic refrigeration cycle in a wide temperature span if it is properly designed, although adequate thermodynamic matching of strongly temperature-dependent MCE (magneto-caloric effect) of the regenerator material and the heat capacity of fluid flow is often tricky due to inherent characteristics of magnetic materials. This paper covers historical developments, fundamental concepts, key components, applications, and recent research trends of AMR refrigerators for liquid helium or liquid hydrogen temperatures.

Jeong, Sangkwon

2014-07-01

253

Macro and Microfluidic Flows for Skeletal Regenerative Medicine  

PubMed Central

Fluid flow has a great potential as a cell stimulatory tool for skeletal regenerative medicine, because fluid flow-induced bone cell mechanotransduction in vivo plays a critical role in maintaining healthy bone homeostasis. Applications of fluid flow for skeletal regenerative medicine are reviewed at macro and microscale. Macroflow in two dimensions (2D), in which flow velocity varies along the normal direction to the flow, has explored molecular mechanisms of bone forming cell mechanotransduction responsible for flow-regulated differentiation, mineralized matrix deposition, and stem cell osteogenesis. Though 2D flow set-ups are useful for mechanistic studies due to easiness in in situ and post-flow assays, engineering skeletal tissue constructs should involve three dimensional (3D) flows, e.g., flow through porous scaffolds. Skeletal tissue engineering using 3D flows has produced promising outcomes, but 3D flow conditions (e.g., shear stress vs. chemotransport) and scaffold characteristics should further be tailored. Ideally, data gained from 2D flows may be utilized to engineer improved 3D bone tissue constructs. Recent microfluidics approaches suggest a strong potential to mimic in vivo microscale interstitial flows in bone. Though there have been few microfluidics studies on bone cells, it was demonstrated that microfluidic platform can be used to conduct high throughput screening of bone cell mechanotransduction behavior under biomimicking flow conditions. PMID:24710552

Riehl, Brandon D.; Lim, Jung Yul

2012-01-01

254

High Energy Density Regenerative Fuel Cell Systems for Terrestrial Applications  

NASA Technical Reports Server (NTRS)

Regenerative Fuel Cell System (RFCS) technology for energy storage has been a NASA power system concept for many years. Compared to battery-based energy storage systems, RFCS has received relatively little attention or resources for development because the energy density and electrical efficiency were not sufficiently attractive relative to advanced battery systems. Even today, RFCS remains at a very low technology readiness level (TRL of about 2 indicating feasibility has been demonstrated). Commercial development of the Proton Exchange Membrane (PEM) fuel cells for automobiles and other terrestrial applications and improvements in lightweight pressure vessel design to reduce weight and improve performance make possible a high energy density RFCS energy storage system. The results from this study of a lightweight RFCS energy storage system for a remotely piloted, solar-powered, high altitude aircraft indicate an energy density up to 790 w-h/kg with electrical efficiency of 53.4% is attainable. Such an energy storage system would allow a solar-powered aircraft to carry hundreds of kilograms of payload and remain in flight indefinitely for use in atmospheric research, earth observation, resource mapping. and telecommunications. Future developments in the areas of hydrogen and oxygen storage, pressure vessel design, higher temperature and higher- pressure fuel cell operation, unitized regenerative fuel cells, and commercial development of fuel cell technology will improve both the energy density and electrical efficiency of the RFCS.

Burke, Kenneth A.

1999-01-01

255

Regeneratively cooled rocket engine for space storable propellants  

NASA Technical Reports Server (NTRS)

Analyses and experimental studies were performed with the OF2 (F2/O2)/B2H6 propellant combination over a range in operating conditions to determine suitability for a space storable pressure fed engine configuration for an extended flight space vehicle configuration. The regenerative cooling mode selected for the thrust chamber was explored in detail with the use of both the fuel and oxidizer as coolants in an advanced milled channel construction thrust chamber design operating at 100 psia chamber pressure and a nominal mixture ratio of 3.0 with a 60:1 area ratio nozzle. Benefits of the simultaneous cooling as related to gaseous injection of both fuel and oxidizer propellants were defined. Heat transfer rates, performance and combustor stability were developed for impinging element triplet injectors in uncooled copper calorimeter hardware with flow, pressure and temperature instrumentation. Evaluation of the capabilities of the B2H6 and OF2 during analytical studies and numerous tests with flow through electrically heated blocks provided design criteria for subsequent regenerative chamber design and fabrication.

Wagner, W. R.; Waldman, B. J.

1973-01-01

256

Generation of gigawatt subnanosecond 1.06 ?m pulses by regenerative amplification in Nd:Glass  

NASA Astrophysics Data System (ADS)

A 0.1 ?J, 40 ps pulse, selected from a TEM 00 Nd:YAG master oscillator has been regeneratively amplified in a single 0.9 cm diameter gain module to the 100 mJ level while preserving both its temporal and spatial characteristics. Scaling of regenerative amplifiers to larger aperture 1.06 ?m lasers is discussed.

Joshi, C.; Corkum, P. B.

1981-01-01

257

Dissemination of Regenerative Medicine in Japan: Promoting commercialization under the regulatory system  

Microsoft Academic Search

Though Japan has surpassed South Korea in terms of research and development (R&D) in the area of regenerative medicine, South Korea has been more successful at commercialization. This paper focuses on the setup and operation of actual systems that consider the promotion of regenerative medicine in Japan. Analysis of the regulatory systems in Japan and South Korea shows a clear

KURATA Kenji; CHOI Youn-Hee

2012-01-01

258

Fault Diagnosis of Regenerative Water Heater Based-On Multi-class Support Vector Machines  

Microsoft Academic Search

The main idea of multi-class support vector machines (SVMs) is described. a multi-class model for regenerative water heater fault diagnosis is presented combining the fuzzy logic and SVMs. The typical faults set of regenerative water heater is built after thoroughly analyzing the relationships between performance parameters and faults. Finally, the model is inspected and verified by an example in a

Lei Wang; Rui-qing Zhang

2009-01-01

259

Integration and Dynamics of a Renewable Regenerative Hydrogen Fuel Cell System  

E-print Network

is presented. In general, the research indicates that the technical challenges associated with hydrogen energyIntegration and Dynamics of a Renewable Regenerative Hydrogen Fuel Cell System by Alvin Peter of the author. #12;ii Supervisory Committee Integration and Dynamics of a Renewable Regenerative Hydrogen Fuel

Victoria, University of

260

Analysis of low temperature solar thermal electric generation using regenerative Organic Rankine Cycle  

Microsoft Academic Search

The innovative configuration of low temperature solar thermal electric generation with regenerative Organic Rankine Cycle (ORC) is designed, mainly consisting of small concentration ratio compound parabolic concentrators (CPC) and the regenerative ORC. Advantages of the innovative configuration such as effectively reducing heat transfer irreversibility and permitting the use of thermal storage with phase change materials (PCMs) are outlined. The numerical

Gang Pei; Jing Li; Jie Ji

2010-01-01

261

Thyroid hormone-responsive pituitary hyperplasia independent of somatostatin receptor 2.  

PubMed

Mice homozygous for the targeted disruption of the glycoprotein hormone alpha-subunit (alphaGsu) display hypertrophy and hyperplasia of the anterior pituitary thyrotropes. Thyrotrope hyperplasia results in tumors in aged alphaGsu(-/-) mice. These adenomatous pituitaries can grow independently as intrascapular transplants in hypothyroid mice, suggesting that they have progressed beyond simple hyperplasia. We used magnetic resonance imaging to follow the growth and regression of thyrotrope adenomatous hyperplasia in response to thyroid hormone treatment and discovered that the tumors retain thyroid hormone responsiveness. Somatostatin (SMST) and its diverse receptors have been implicated in cell proliferation and tumorigenesis. To test the involvement of SMST receptor 2 (SMSTR2) in pituitary tumor progression and thyroid hormone responsiveness in alphaGsu(-/-) mutants, we generated Smstr2(-/-), alphaGsu(-/-) mice. Smstr2(-/-), alphaGsu(-/-) mice develop hyperplasia of thyrotropes, similar to alphaGsu(-/-) mutants, demonstrating that SMSTR2 is dispensable for the development of pituitary adenomatous hyperplasia. Thyrotrope hyperplasia in Smstr2(-/-), alphaGsu(-/-) mice regresses in response to T4 treatment, suggesting that SMSTR2 is not required in the T4 feedback loop regulating TSH secretion. PMID:11731614

Brinkmeier, M L; Stahl, J H; Gordon, D F; Ross, B D; Sarapura, V D; Dowding, J M; Kendall, S K; Lloyd, R V; Ridgway, E C; Camper, S A

2001-12-01

262

Pulmonary neuroendocrine cell hyperplasia: identification, diagnostic criteria and incidence in untreated ageing rats of different strains.  

PubMed

Pulmonary Neuroendocrine Cells (PNEC) are found as clusters called neuroepithelial bodies (NEB) or as single cells scattered in the respiratory epithelium. Pulmonary neuroendocrine cell hyperplasia is recorded in humans and experimentally manipulated rodents. The objectives of this work were to identify the optimal immunohistochemical markers for PNEC in the rat for use on paraffin-embedded, formalin-fixed material and to provide the first comparative incidence of PNEC hyperplasia in untreated 2-year-old rats of different strains. Calcitonin-gene related peptide (CGRP) and protein G product 9.5 (PGP9.5) antibodies identified PNEC consistently and selectively. In contrast, PNEC did not express chromogranin-A or S-100. PNEC hyperplasia was defined as foci of PNEC with greater than 40 nuclei, excluding overlying respiratory epithelium and submucosal PNEC. PNEC hyperplasia was observed at low incidence (0-7%) in untreated 2-year-old Sprague-Dawley, Han Wistar and Wistar rats but not Fischer 344 rats. This is the first report of spontaneous PNEC hyperplasia in rats. The cause of this hyperplasia is unknown, but experimental models that induce PNEC hyperplasia by causing bronchiolar cell injury are discussed. PNEC neoplasia in the rat is unreported in the literature and was not observed in animals examined in this study. PMID:17849355

Haworth, Richard; Woodfine, Jennie; McCawley, Sean; Pilling, Andrew M; Lewis, David J; Williams, Tom C

2007-08-01

263

The role of imaging in congenital adrenal hyperplasia.  

PubMed

Congenital adrenal hyperplasia (CAH) is an autossomic recessive disorder caused by impaired steroidogenesis. Patients with CAH may present adrenal insufficiency with or without salt-wasting, as well as various degrees of virilization and fertility impairment, carrying a high incidence of testicular adrenal rest tumors and increased incidence of adrenal tumors. The diagnosis of CAH is made based on the adrenocortical profile hormonal evaluation and genotyping, in selected cases. Follow-up is mainly based on hormonal and clinical evaluation. Utility of imaging in this clinical setting may be helpful for the diagnosis, management, and follow-up of the patients, although recommendations according to most guidelines are weak when present. Thus, the authors aimed to conduct a narrative synthesis of how imaging can help in the management of patients with CAH, especially focused on genitography, ultrasonography, computed tomography, and magnetic resonance imaging. PMID:25372578

Teixeira, Sara Reis; Elias, Paula Condé Lamparelli; Andrade, Marco Túlio Soares; Melo, Andrea Farias; Elias Junior, Jorge

2014-10-01

264

Splicing factor SRSF6 promotes hyperplasia of sensitized skin  

PubMed Central

Summary Many biological processes involve gene-expression regulation by alternative splicing. Here, we identify the splicing factor SRSF6 as a regulator of wound healing and tissue homeostasis in skin. We show that SRSF6 is a proto-oncogene that is frequently overexpressed in human skin cancer. Overexpressing it in transgenic mice induces hyperplasia of sensitized skin and promotes aberrant alternative splicing. We identify 139 target genes of SRSF6 in skin, and show that this SR protein binds to alternative exons of the extracellular-matrix protein tenascin C pre-mRNA, promoting the expression of isoforms characteristic of invasive and metastatic cancer in a cell-type-independent manner. SRSF6 overexpression additionally results in depletion of Lgr6+ stem cells, and excessive keratinocyte proliferation and response to injury. Furthermore, the effects of SRSF6 in wound healing assayed in vitro depend on the TNC isoforms. Thus, abnormal SR-protein expression can perturb tissue homeostasis. PMID:24440982

Jensen, Mads A.; Wilkinson, John E.; Krainer, Adrian R.

2014-01-01

265

Silodosin in the treatment of benign prostatic hyperplasia  

PubMed Central

Benign prostatic hyperplasia (BPH)-associated lower urinary tract symptoms (LUTS) are highly prevalent in older men. Medical therapy is the first-line treatment for LUTS due to BPH. Alpha-adrenergic receptor blockers remain one of the mainstays in the treatment of male LUTS and clinical BPH. They exhibit early onset of efficacy with regard to both symptoms and flow rate improvement, and this is clearly demonstrated in placebo-controlled trials with extensions out to five years. These agents have been shown to prevent symptomatic progression of the disease. The aim of this article is to offer a critical review of the current literature on silodosin, formerly known as KMD-3213, a novel alpha-blocker with unprecedented selectivity for ?1A-adrenergic receptors, as compared with both ?1B- and ?1D -adrenoceptors, exceeding the selectivity of all currently used ?1-blockers, and with clinically promising effects. PMID:21116335

Rossi, Maxime; Roumeguère, Thierry

2010-01-01

266

Left ventricular haemangioma with papillary endothelial hyperplasia and liver involvement.  

PubMed

An intracardiac haemangioma with papillary endothelial hyperplasia (PEH) and liver involvement has not been previously reported in the English literature. This report describes a 65 year old man with a left ventricular haemangioma with PEH coexistent with multiple nodular hepatic haemangiomas. Transthoracic and transoesophageal echocardiography identified a large tumour in the left ventricular cavity with a pedicle connected to the apex. Abdominal sonography also identified multiple hyperechoic hepatic tumours. Magnetic resonance imaging showed hypervascularity of both the cardiac and hepatic lesions. The left ventricular tumour was totally resected and the liver nodules were biopsied. Tissue pathological study showed that both the left ventricular tumour and liver lesions were haemangiomas with PEH. The patient was discharged without complications postoperatively. PMID:15253991

Kan, C-D; Yae, C-T; Yang, Y-J

2004-08-01

267

[The transurethral microwave thermotherapy of benign prostatic hyperplasia].  

PubMed

The authors have treated benign prostatic hyperplasia (BPH) in 50 patients aged 54-89 years (mean age 67.5 years) including 10 patients with cystostoma. The patients were exposed to transurethral microwave thermotherapy (TUMT) performed on the prostcare unit. Only 1 session (60 min at 45 degrees C) was conducted. Inflammatory complications of TUMT occurred in 4(8%) patients. A 1.5-year follow-up covered 45 patients. A subjective response was obtained in 86% of patients. An objective response by urination rate and prostatic size 3 months after TUMT was reached in 80 and 90% of patients, respectively; 1.5 years after in 48, 34 and 47%, respectively. TUMT is recommended in uncomplicated BPH as an alternative to chemotherapy or surgical treatment (in patients with cystostoma and serious intercurrent diseases). PMID:9381615

Prokhorov, A V; Karpov, V K; Sivkov, A V; Apolikhin, O I; Ignashin, N S; Churakov, B I

1997-01-01

268

Esophageal intraepithelial invasion of Helicobacter pylori correlates with atypical hyperplasia.  

PubMed

Helicobacter pylori (H. pylori), a common pathogen residing in the gastrointestinal tract, has been well characterized in stomach cancer,while its correlation with esophageal cancer remains poorly understood. In this study, we aim to assess the relationship between esophageal intraepithelial H. pylori invasion and inflammation as well as atypical hyperplasia in esophageal squamous epithelial tissues. Esophageal squamous cell carcinoma (ESCC) tissue samples from 196 individuals from both southern and northern esophageal carcinoma high-risk areas in China were examined (125 from northern high-risk areas, 71 from southern high-risk area), while additional 30 samples were collected adjacent to the esophageal squamous cell carcinoma (A-ESCC). H. pylori infection was identified by Giemsa staining, immuno-histochemical staining, and H. pylori 16S rRNA-based PCR. A significant increase of H. pylori infection was found in tumor tissues (including ESCC and A-ESCC samples) compared to that of non-tumor tissues (p?hyperplasia of esophageal squamous epithelial tissues and contributed to pathological carcinogenesis of ESCC. PMID:24254881

Li, Wen-sheng; Tian, Dong-ping; Guan, Xiao-ying; Yun, Hailong; Wang, Hong-tao; Xiao, Yinping; Bi, Chao; Ying, Songmin; Su, Min

2014-06-01

269

Serenoa repens extract in the treatment of benign prostatic hyperplasia.  

PubMed

We are experiencing a revival of interest in phytotherapeutic agents, both in Europe and North America, especially as a consequence of patients' dissatisfaction with the adverse effects of the medical alternatives. One of the most frequently prescribed and studied such agents is Serenoa repens extract, derived from the berry of the dwarf palm tree. We aimed to review the most important published data regarding this type of treatment for benign prostatic hyperplasia. A review of the existing articles regarding the use of Serenoa repens extracts for benign prostatic hyperplasia was performed. The articles were analysed with regard to their relevance, scientific value and the size of the evaluated series. Multiple mechanisms of action have been attributed to this extract, including antiandrogenic action, an anti-inflammatory/anti-oedematous effect, prolactin signal modulation, and an antiproliferative effect exerted through the inhibition of growth factors. Regarding efficacy, European Association of Urology guidelines state that Serenoa repens extracts significantly reduce nocturia in comparison with placebo. However, the guideline committee is unable to make specific recommendations about phytotherapy of male lower urinary tract symptoms owing to the heterogeneity of the products and the methodological problems associated with meta-analyses. Most of the published trials regarding Serenoa repens phytotherapy demonstrate a significant improvement of urinary status and a favourable safety profile. Also, some authors have credited it with giving a significant improvement in erectile function and decreasing complications following transurethral resection of the prostate, especially bleeding. The results of phytotherapy with Serenoa repens extracts are very promising. More high-quality, randomized, placebo-controlled studies are required in order to demonstrate without doubt the true therapeutic value of these products. Particular attention must be focused on differentiating between registered preparations, which are regulated as drugs, and those considered to be food supplements. PMID:21969849

Geavlete, Petrisor; Multescu, Razvan; Geavlete, Bogdan

2011-08-01

270

Sodium Ferulate Inhibits Neointimal Hyperplasia in Rat Balloon Injury Model  

PubMed Central

Background/Aim Neointimal formation after vessel injury is a complex process involving multiple cellular and molecular processes. Inhibition of intimal hyperplasia plays an important role in preventing proliferative vascular diseases, such as restenosis. In this study, we intended to identify whether sodium ferulate could inhibit neointimal formation and further explore potential mechanisms involved. Methods Cultured vascular smooth muscle cells (VSMCs) isolated from rat thoracic aorta were pre-treated with 200 µmol/L sodium ferulate for 1 hour and then stimulated with 1 µmol/L angiotensin II (Ang II) for 1 hour or 10% serum for 48 hours. Male Sprague-Dawley rats subjected to balloon catheter insertion were administrated with 200 mg/kg sodium ferulate (or saline) for 7 days before sacrificed. Results In presence of sodium ferulate, VSMCs exhibited decreased proliferation and migration, suppressed intracellular reactive oxidative species production and NADPH oxidase activity, increased SOD activation and down-regulated p38 phosphorylation compared to Ang II-stimulated alone. Meanwhile, VSMCs treated with sodium ferulate showed significantly increased protein expression of smooth muscle ?-actin and smooth muscle myosin heavy chain protein. The components of Notch pathway, including nuclear Notch-1 protein, Jagged-1, Hey-1 and Hey-2 mRNA, as well as total ?-catenin protein and Cyclin D1 mRNA of Wnt signaling, were all significantly decreased by sodium ferulate in cells under serum stimulation. The levels of serum 8-iso-PGF2? and arterial collagen formation in vessel wall were decreased, while the expression of contractile markers was increased in sodium ferulate treated rats. A decline of neointimal area, as well as lower ratio of intimal to medial area was observed in sodium ferulate group. Conclusion Sodium ferulate attenuated neointimal hyperplasia through suppressing oxidative stress and phenotypic switching of VSMCs. PMID:24489938

Chen, Jing; Xu, Changwu; Ding, Jiawang; Yang, Jun; Guo, Qing; Hu, Qi; Jiang, Hong

2014-01-01

271

Thymic cystic degeneration, pseudoepitheliomatous hyperplasia, and hemorrhage in a dog with brodifacoum toxicosis.  

PubMed

Thymic cysts with pseudoepitheliomatous hyperplasia are described in a 7-month-old female American Eskimo Dog that died of complications from brodifacoum poisoning. Grossly, there was hemothorax with marked cranial mediastinal hemorrhage. Histologically, thymic lobules were expanded and distorted by irregular cysts, lined by single to multiple layers of plump to slightly attenuated polygonal squamous epithelial cells supported by a basement membrane (pseudoepitheliomatous hyperplasia). The thymus had a paucity of lymphocytes and lacked corticomedullary differentiation. Extensive hemorrhage within the cysts and thymic parenchyma extended into the adjacent adipose tissue. To the authors' knowledge, this is the first report of cystic thymic degeneration with pseudoepitheliomatous hyperplasia in a nonhuman species. PMID:19176509

Rickman, B H; Gurfield, N

2009-05-01

272

Testicular Adrenal Rest Tumors in a Patient with Congenital Adrenal Hyperplasia  

PubMed Central

Congenital adrenal hyperplasia refers to a group of autosomal recessive disorders caused by a deficiency of an enzyme involved in the synthesis of glucocorticoids. The enzyme deficiency generally leads to a deficiency of cortisol and/or aldosterone production within the adrenal cortex. The lack of glucocorticoids generally leads to elevated levels of plasma corticotropin (ACTH), which often results in adrenal hyperplasia. Testicular adrenal rest tumors may develop in males with congenital adrenal hyperplasia due to overstimulation of aberrant adrenal cells within the testes. Recognition of this disease entity is essential when evaluating young males with testicular masses. PMID:24967019

Olpin, Jeffrey Dee; Witt, Benjamin

2014-01-01

273

Intestinal nodular lymphoid hyperplasia and extraintestinal lymphoma--a rare association.  

PubMed

Nodular lymphoid hyperplasia of the gastrointestinal tract is characterized by the presence of innumerable small discrete nodules involving a variable segment of the gastrointestinal tract. The association between nodular lymphoid hyperplasia and other benign and malignant diseases has been clearly described, with an increased risk of gastrointestinal tumours, namely gastrointestinal lymphoma. However, the association with extraintestinal lymphoma seems extremely rare. The authors present a clinical case of a patient with nodular lymphoid hyperplasia of the small and large intestine that subsequently developed an extraintestinal lymphoma (diffuse large B-cell lymphoma). PMID:22870792

Monsanto, P; Lérias, C; Almeida, N; Lopes, S; Cabral, J E; Figueiredo, P; Silva, M; Julião, M; Gouveia, H; Sofia, C

2012-06-01

274

Nanotechnology-based approaches for regenerative medicine and biosensing  

NASA Astrophysics Data System (ADS)

The recent emergence of nanotechnology has set high expectations in many fields of science, especially in biology and medicine. Nanotechnology-based approaches are expected to solve key questions in the emerging field of regenerative medicine. Regenerative medicine essentially deals with regeneration of cells, ultimately leading to the formation of tissues and organs. For this purpose, stem cells, embryonic stem cells or adult stem cells, are thought to be ideal resources. However, many challenges need to be addressed before the full therapeutic potential of stem cells can be harnessed. Controlling the differentiation of stem cells into cells of a specific lineage is extremely vital and challenging. Addressing this challenge, in this work, novel nanotechnology-based approaches for controlling the differentiation of neural stem cells (NSCs) into neurons has been presented. Regeneration of damaged neurons, due to traumatic injuries or degenerative diseases, is extremely challenging. For this purpose, NSCs can be used as resources that can differentiate into neurons, thus having great potential in solving needs of many patients suffering from such conditions. For controlling the differentiation of stem cells, soluble cues (comprising of small molecules and biomolecules) and insoluble cues (cell-cell interactions and cell-microenvironment interactions) play a very important role. The delivery of soluble cues, such as genetic material, into stem cells is extremely challenging. The initial part of this work presents the use of nanomaterials for efficiently delivering soluble cues such as small molecules and small interfering RNA (siRNA) into NSCs for controlling their differentiation into neurons. However, for regenerative purposes, it is preferred that least amounts of the delivery vehicle be used. Thus, the following part of the thesis presents the development and applications of nanotechnology-based approaches for enhancing the differentiation of NSCs into neurons using insoluble cues. The cellular microenvironment, consisting for the extracellular matrix (ECM) was modified by the use of nanostructures, to deliver siRNA into NSCs to enhance neuronal differentiation. Nanotopography-mediated reverse uptake of only the siRNA molecules from the ECM was achieved by the NSCs. NSC differentiation was also controlled by the use of protein micropatterns, wherein the pattern geometry and size defined the fate of the NSCs. Lastly, graphene, in combination with nanoparticles was used as component of the ECM to not only enhance the differentiation of NSCs into neurons, but also align the axons of the differentiated NSCs, having significant implications for its use in regenerating injured spinal cords. The final portion of the thesis presents the applications of nanotechnology for developing highly sensitive and selective biosensors, for detecting biomarkers implicated in various diseases such as cancer and acute pancreatitis.

Solanki, Aniruddh P.

275

Regenerative braking device with rotationally mounted energy storage means  

DOEpatents

A regenerative braking device for an automotive vehicle includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (30) and an output shaft (32), clutches (50, 56) and brakes (52, 58) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. In a second embodiment the clutches and brakes are dispensed with and the variable ratio transmission is connected directly across the input and output shafts. In both embodiments the rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft rotates faster or relative to the output shaft and are torsionally relaxed to deliver energy to the vehicle when the output shaft rotates faster or relative to the input shaft.

Hoppie, Lyle O. (Birmingham, MI)

1982-03-16

276

Support testing and design study evaluation of regenerative air heaters  

NASA Astrophysics Data System (ADS)

Progress on the ceramic heater development program for coal-fired MHD generators is summarized. Tasks include: (1) analytical studies of full scale heaters to evaluate fullscale directly and indirectly fired regenerative air heaters suitable for use in a combined MHD-steam power plant; (2) engineering design of heater test module to design a directly-fired air heater test module suitable for construction and testing under realistic, dynamic conditions expected in an MHD power generation system; (3) design support tests to provide a basis for the analytical and design studies of (1) and (2), and to provide design, operational, and material data based on model experiments to optimize the geometry of bed components and to provide techniques to control seed and slag deposit buildup in the bed and connecting ducts; (4) liaison with materials testing and development activities to ensure maximum transfer and utilization of current materials testing and development technology.

1977-04-01

277

Treatment Options: Biological Basis of Regenerative Endodontic Procedures  

PubMed Central

Dental trauma occurs frequently in children and often can lead to pulpal necrosis. The occurrence of pulpal necrosis in the permanent but immature tooth represents a challenging clinical situation since the thin and often short roots increase the risk of subsequent fracture. Current approaches for treating the traumatized immature tooth with pulpal necrosis do not reliably achieve the desired clinical outcomes, consisting of healing of apical periodontitis, promotion of continued root development and restoration of the functional competence of pulpal tissue. An optimal approach for treating the immature permanent tooth with a necrotic pulp would be to regenerate functional pulpal tissue. This review summarizes the current literature supporting a biological rationale for considering regenerative endodontic treatment procedures in treating the immature permanent tooth with pulp necrosis. PMID:23439043

Hargreaves, Kenneth M.; Diogenes, Anibal; Teixeira, Fabricio B.

2013-01-01

278

Stem cells as tools in regenerative therapy for retinal degeneration  

PubMed Central

Objectives Regenerative medicine intends to provide therapies for severe injuries or chronic diseases where endogenous repair does not sufficiently restore the tissue. Pluripotent stem cells (SC), with their capacity to give rise to specialized cells, are the most promising candidates for clinical application. Despite encouraging results, a combination with up-to-date tissue engineering might be critical for ultimate success. Design The focus is on the use of SC for regeneration of retinal degenerations. Cell populations include embryonic, neural, and bone marrow-derived SC and engineered grafts will also be described. Results Experimental approaches have successfully replaced damaged photoreceptors and retinal pigment epithelium using endogenous and exogenous SC. Conclusions SC have the potential to significantly impact retinal regeneration. A combination with bioengineering may bear even greater promise. However, ethical and scientific issues have yet to be solved. PMID:19365041

Enzmann, Volker; Yolcu, Esma; Kaplan, Henry J.; Ildstad, Suzanne T.

2011-01-01

279

Regenerative oscillation and four-wave mixing in graphene optoelectronics  

E-print Network

The unique linear and massless band structure of graphene, in a purely two-dimensional Dirac fermionic structure, have led to intense research spanning from condensed matter physics to nanoscale device applications covering the electrical, thermal, mechanical and optical domains. Here we report three consecutive first-observations in graphene-silicon hybrid optoelectronic devices: (1) ultralow power resonant optical bistability; (2) self-induced regenerative oscillations; and (3) coherent four-wave mixing, all at a few femtojoule cavity recirculating energies. These observations, in comparison with control measurements with solely monolithic silicon cavities, are enabled only by the dramatically-large and chi(3) nonlinearities in graphene and the large Q/V ratios in wavelength-localized photonic crystal cavities. These results demonstrate the feasibility and versatility of hybrid two-dimensional graphene-silicon nanophotonic devices for next-generation chip-scale ultrafast optical communications, radio-freque...

Gu, Tingyi; Yang, Xiaodong; McMillian, James F; van der Zander, Arend; Yu, Min-bing; Lo, Guo-Qiang; Kwong, Dim-Lee; Hone, James; Wong, Chee-Wei

2012-01-01

280

Hydrodynamic parameters of mesh fillers relevant to miniature regenerative cryocoolers  

NASA Astrophysics Data System (ADS)

Directional hydrodynamic parameters of two fine-mesh porous materials that are suitable for miniature regenerative cryocoolers were studied under steady and oscillating flows of helium. These materials included stacked discs of #635 stainless steel (wire diameter of 20.3 ?m) and #325 phosphor bronze (wire diameter of 35.6 ?m) wire mesh screens, which are among the commercially available fillers for use in small-scale regenerators and heat exchangers, respectively. Experiments were performed in test sections in which pressure variations across these fillers, in the axial and lateral (radial) directions, were measured under steady and oscillatory flows. The directional permeability and Forchheimer's inertial coefficient were then obtained by using a Computational Fluid Dynamics (CFD)-assisted method. The oscillatory flow experiments covered a frequency range of 50-200 Hz. The results confirmed the importance of anisotropy in the mesh screen fillers, and indicated differences between the directional hydrodynamic resistance parameters for steady and oscillating flow regimes.

Landrum, E. C.; Conrad, T. J.; Ghiaasiaan, S. M.; Kirkconnell, Carl S.

2010-06-01

281

Free-piston regenerative hot gas hydraulic engine  

NASA Technical Reports Server (NTRS)

A displacer piston which is driven pneumatically by a high-pressure or low-pressure gas is included in a free-piston regenerative hydraulic engine. Actuation of the displacer piston circulates the working fluid through a heater, a regenerator and a cooler. The present invention includes an inertial mass such as a piston or a hydraulic fluid column to effectively store and supply energy during portions of the cycle. Power is transmitted from the working fluid to a hydraulic fluid across a diaphragm or lightweight piston to achieve a hydraulic power out-put. The displacer piston of the present invention may be driven pneumatically, hydraulically or electromagnetically. In addition, the displacer piston and the inertial mass of the present invention may be positioned on the same side of the diaphragm member or may be separated by the diaphragm member.

Beremand, D. G. (inventor)

1980-01-01

282

Regenerative fuel cell study for satellites in GEO orbit  

NASA Technical Reports Server (NTRS)

The results of a 12 month study to identify high performance regenerative hydrogen-oxygen fuel cell concepts for geosynchronous satellite application are summarized. Emphasis was placed on concepts with the potential for high energy density and passive means for water and heat management to maximize system reliability. Both polymer membrane and alkaline electrolyte fuel cells were considered, with emphasis on the alkaline cell because of its high performance, advanced state of development, and proven ability to operate in a launch and space environment. Three alkaline system concepts were studied. Results indicate that using near term technology energy densities between 46 and 52 watt-hour/lb can be achieved at efficiencies of 55 percent. Using advanced light weight cell construction which was achieved in experimental cells, composite tankage material for the reactant gases and the reversible stack concept, system energy densities of 115 watt-hours/lb can be projected.

Van Dine, Leslie; Levy, Alexander; Gonzalez-Sanabria, Olga

1987-01-01

283

Regenerative medicine for retinal diseases: activating the endogenous repair mechanisms  

PubMed Central

The retina is subject to degenerative diseases that often lead to significant visual impairment. Non-mammalian vertebrates have a remarkable ability to replace neurons lost through damage. Fish, and to a limited extent birds, replace lost neurons by de-differentiation of Müller glia to a progenitor state followed by replication of these neuronal progenitor cells. Over the past five years, studies have investigated whether regeneration can be stimulated in the mouse and rat retina. Several groups have reported that at least some types of neurons can be regenerated in the mammalian retina in vivo or in vitro, and that the regeneration of neurons can be stimulated using growth factors, transcription factors or subtoxic levels of excitatory amino acids. These recent results suggest that some part of the regenerative program that occurs in non-mammalian vertebrates remains in the mammalian retina, and may provide a basis to develop new strategies for retinal repair in patients with retinal degenerations. PMID:20303826

Karl, M. O.; Reh, T. A.

2010-01-01

284

Microbiological characterization of a regenerative life support system  

NASA Astrophysics Data System (ADS)

A Variable Pressure Plant Growth Chamber (VPGC), at the Johnson Space Center's (JSC) ground-based Regenerative Life Support Systems (RLSS) test bed, was used to produce crops of soil-grown lettuce. The crops and chamber were analyzed for microbiological diversity during lettuce growth and after harvest. Bacterial counts for the rhizosphere, spent nutrient medium, heat exchanger condensate, and atmosphere were approximately 1011 Colony Forming Units (CFU) g-1, 105 CFU ml-1, 105 CFU ml-1, and 600 CFU m-3, respectively. Pseudomonas was the predominant bacterial genus. Numbers of fungi were about 105 CFU g-1 in the rhizosphere, 4-200 CFU ml-1 in thespent nutrient medium, 110 CFU ml-1 in the heat exchanger condensate, and 3 CFU m-3 in the atmosphere. Fusarium and Trichoderma were the predominant fungal genera.

Koenig, D. W.; Bruce, R. J.; Mishra, S. K.; Barta, D. J.; Pierson, D. L.

1994-11-01

285

Bioengineering Heart Muscle: A Paradigm for Regenerative Medicine  

PubMed Central

The idea of extending the lifetime of our organs is as old as humankind, fueled by major advances in organ transplantation, novel drugs, and medical devices. However, true regeneration of human tissue has becoming increasingly plausible only in recent years. The human heart has always been a focus of such efforts, given its notorious inability to repair itself following injury or disease. We discuss here the emerging bioengineering approaches to regeneration of heart muscle as a paradigm for regenerative medicine. Our focus is on biologically inspired strategies for heart regeneration, knowledge gained thus far about how to make a “perfect” heart graft, and the challenges that remain to be addressed for tissue-engineered heart regeneration to become a clinical reality. We emphasize the need for interdisciplinary research and training, as recent progress in the field is largely being made at the interfaces between cardiology, stem cell science, and bioengineering. PMID:21568715

Lui, Kathy O.; Tandon, Nina

2012-01-01

286

Simple Signaling Molecules for Inductive Bone Regenerative Engineering  

PubMed Central

With greater than 500,000 orthopaedic procedures performed in the United States each year requiring a bone graft, the development of novel graft materials is necessary. We report that some porous polymer/ceramic composite scaffolds possess intrinsic osteoinductivity as shown through their capacity to induce in vivo host osteoid mineralization and in vitro stem cell osteogenesis making them attractive synthetic bone graft substitutes. It was discovered that certain low crystallinity ceramics partially dissociate into simple signaling molecules (i.e., calcium and phosphate ions) that induce stem cells to endogenously produce their own osteoinductive proteins. Review of the literature has uncovered a variety of simple signaling molecules (i.e., gases, ions, and redox reagents) capable of inducing other desirable stem cell differentiation through endogenous growth factor production. Inductive simple signaling molecules, which we have termed inducerons, represent a paradigm shift in the field of regenerative engineering where they can be utilized in place of recombinant protein growth factors. PMID:25019622

Nelson, Stephen J.; Deng, Meng; Sethuraman, Swaminathan; Doty, Stephen B.; Lo, Kevin W. H.; Khan, Yusuf M.; Laurencin, Cato T.

2014-01-01

287

Regenerative Life Support Systems Test Bed performance - Lettuce crop characterization  

NASA Technical Reports Server (NTRS)

System performance in terms of human life support requirements was evaluated for two crops of lettuce (Lactuca sative cv. Waldmann's Green) grown in the Regenerative Life Support Systems Test Bed. Each crop, grown in separate pots under identical environmental and cultural conditions, was irrigated with half-strength Hoagland's nutrient solution, with the frequency of irrigation being increased as the crop aged over the 30-day crop tests. Averaging over both crop tests, the test bed met the requirements of 2.1 person-days of oxygen production, 2.4 person-days of CO2 removal, and 129 person-days of potential potable water production. Gains in the mass of water and O2 produced and CO2 removed could be achieved by optimizing environmental conditions to increase plant growth rate and by optimizing cultural management methods.

Barta, Daniel J.; Edeen, Marybeth A.; Eckhardt, Bradley D.

1992-01-01

288

Regenerative flywheel energy storage system. Volume 1: Executive summary  

NASA Astrophysics Data System (ADS)

The development, fabrication, and test of a regenerative flywheel energy storage and recovery system for a battery/flywheel electric vehicle of the 3000 pound class are described. The vehicle propulsion system was simulated on a digital computer in order to determine the optimum system operating strategies and to establish a calculated range improvement over a nonregenerative, all electric vehicle. Fabrication of the inductor motor, the flywheel, the power conditioner, and the system control are described. Test results of the system operating over the SAE J227a Schedule D driving cycle are given and are compared to the calculated value. The flywheel energy storage system consists of a solid rotor, synchronous, inductor type, flywheel drive machine electrically coupled to a dc battery electric propulsion system through a load commutated inverter. The motor/alternator unit is coupled mechanically to a small steel flywheel which provides a portion of the vehicle's accelerating energy and regenerates the vehicle's braking energy.

1980-06-01

289

Mesenchymal stem cell and regenerative medicine: regeneration versus immunomodulatory challenges  

PubMed Central

Mesenchymal Stem cells (MSC) are now presented with the opportunities of multifunctional therapeutic approaches. Several reports are in support of their self-renewal, capacity for multipotent differentiation, and immunomodulatory properties. They are unique to contribute to the regeneration of mesenchymal tissues such as bone, cartilage, muscle, ligament, tendon, and adipose. In addition to promising trials in regenerative medicine, such as in the treatment of major bone defects and myocardial infarction, MSC has shown a therapeutic effect other than direct hematopoiesis support in hematopoietic reconstruction. MSCs are identified by the expression of many molecules including CD105 (SH2) and CD73(SH3/4) and are negative for the hematopoietic markers CD34, CD45, and CD14. Manufacturing of MSC for clinical trials is also an important aspect as their differentiation, homing and Immunomodulatory properties may differ. Their suppressive effects on immune cells, including T cells, B cells, NK cells and DC cells, suggest MSCs as a novel therapy for GVHD and other autoimmune disorders. Since the cells by themselves are non-immunogenic, tissue matching between MSC donor and recipient is not essential and, MSC may be the first cell type able to be used as an “off-the-shelf” therapeutic product. Following a successful transplantation, the migration of MSC to the site of injury refers to the involvement of chemokines and chemokine receptors of respective specificity. It has been demonstrated that cultured MSCs have the ability to engraft into healthy as well as injured tissue and can differentiate into several cell types in vivo, which facilitates MSC to be an ideal tool for regenerative therapy in different disease types. However, some observations have raised questions about the limitations for proper use of MSC considering some critical factors that warn regular clinical use. PMID:23671814

Law, Sujata; Chaudhuri, Samaresh

2013-01-01

290

Performance analysis of reciprocating regenerative magnetic heat pumping. Final report  

SciTech Connect

Transient flow phenomena in the regenerator tube of reciprocating magnetic heat pumps have been studied numerically and experimentally. In the numerical study, two approaches were taken: (1) solving the energy balance equations for fluid through a porous bed directly and (2) solving the Navier-Stokes equations with a buoyancy force term in the momentum equation. A flow thermal mixing problem was found in both approaches because of the piston-like motion of the regenerator tube that hinders the development of the temperature. The numerical study results show that a 45 K temperature span can be reached in 10 minutes of charge time through the use of a 7-Tesla magnetic field. Using the second numerical approach, temperature stratification in the regenerator fluid column was clearly indicated through temperature rasters. The study also calculates regenerator efficiency and energy delivery rates when heating load and cooling load are applied. Piecewise variation of the regenerator tube moving speed has been used in the present numerical study to control the mass flow rate, reduce thermal mixing of the flow and thus the regenerative losses. The gadolinium`s adiabatic temperature has been measured under 6.5 Tesla of magnet field and different of operating temperatures ranging from 285 K to 320 K. Three regenerative heat pumping tests have also been conducted based on the Reynolds number of the regenerator tube flow, namely Re=300, Re=450, and Re=750 without loads. Maximum temperature span are 12 & 11 K and 9 K for the case of Re=300, Re=450 and Re=750, respectively. Experimental data are in good agreement with the numerical calculation results, and have been used to calibrate the numerical results and to develop a design database for reciprocating-type room-temperature magnetic heat pumps.

Chen, D.T. [Oak Ridge Associated Universities, Inc., TN (United States); Murphy, R.W.; Mei, V.C.; Chen, F.C.; Lue, J.W.; Lubell, M.S. [Oak Ridge National Lab., TN (United States)

1994-02-01

291

Particle assemblies: toward new tools for regenerative medicine.  

PubMed

Regenerative medicine is a demanding field in terms of design and elaboration of materials able to meet the specifications that this application imposes. The regeneration of tissue is a multiscale issue, from the signaling molecule through cell expansion and finally tissue growth requiring a large variety of cues that should be delivered in place and time. Hence, the materials should be able to accommodate cells with respect to their phenotypes, to allow cell division to the right tissue, to maintain the integrity of the surrounding sane tissue, and eventually use their signaling machinery to serve the development of the appropriate neo-tissue. They should also present the ability to deliver growth factors and regulate tissue development, to be degraded into safe products, in order not to impede tissue development, and finally be easily implanted/injected into the patients. In this context, colloid-based materials represent a very promising family of products because one can take advantage of their high specific area, their capability to carry/deliver bio-active molecules, and their capacity of assembling (eventually in vivo) into materials featuring other mechanical, rheological, physicochemical properties. Other benefits of great interest would be their ease of production even via high through-put processes and their potential manufacturing from safe, biodegradable and biocompatible parent raw material. This review describes the state-of-the-art of processes leading to complex materials from the assembly of colloids meeting, at least partially, the above-described specifications for tissue engineering and regenerative medicine. PMID:23827536

Roux, R; Ladavière, C; Montembault, A; Delair, T

2013-04-01

292

Geroconversion of aged muscle stem cells under regenerative pressure.  

PubMed

Regeneration of skeletal muscle relies on a population of quiescent stem cells (satellite cells) and is impaired in very old (geriatric) individuals undergoing sarcopenia. Stem cell function is essential for organismal homeostasis, providing a renewable source of cells to repair damaged tissues. In adult organisms, age-dependent loss-of-function of tissue-specific stem cells is causally related with a decline in regenerative potential. Although environmental manipulations have shown good promise in the reversal of these conditions, recently we demonstrated that muscle stem cell aging is, in fact, a progressive process that results in persistent and irreversible changes in stem cell intrinsic properties. Global gene expression analyses uncovered an induction of p16(INK4a) in satellite cells of physiologically aged geriatric and progeric mice that inhibits satellite cell-dependent muscle regeneration. Aged satellite cells lose the repression of the INK4a locus, which switches stem cell reversible quiescence into a pre-senescent state; upon regenerative or proliferative pressure, these cells undergo accelerated senescence (geroconversion), through Rb-mediated repression of E2F target genes. p16(INK4a) silencing rejuvenated satellite cells, restoring regeneration in geriatric and progeric muscles. Thus, p16(INK4a)/Rb-driven stem cell senescence is causally implicated in the intrinsic defective regeneration of sarcopenic muscle. Here we discuss on how cellular senescence may be a common mechanism of stem cell aging at the organism level and show that induction of p16(INK4a) in young muscle stem cells through deletion of the Polycomb complex protein Bmi1 recapitulates the geriatric phenotype. PMID:25485497

Sousa-Victor, Pedro; Perdiguero, Eusebio; Muñoz-Cánoves, Pura

2014-10-15

293

Prostate Tissue Composition and Response to Finasteride in Men With Symptomatic Benign Prostatic Hyperplasia  

Microsoft Academic Search

PurposeWe sought to quantify prostate tissue changes induced by finasteride and to identify a predictor of finasteride response in men with symptomatic benign prostatic hyperplasia (BPH) via a randomized, placebo controlled, double-blind clinical trial.

Leonard S. Marks; Alan W. Partin; Glenn J. Gormley; Frederick J. Dorey; Erlinda D. Shery; Joel B. Garris; Eric N. P. Subong; Elizabeth Stoner; Jean B. deKernion

1997-01-01

294

Long-term 6-year experience with finasteride in patients with benign prostatic hyperplasia  

Microsoft Academic Search

ObjectivesTo summarize the 6-year clinical trial data with finasteride. Benign prostatic hyperplasia is a chronic and progressive disease and therefore assessment of long-term safety and efficacy is important.

Franklin C Lowe; John D McConnell; Perry B Hudson; Nicholas A Romas; Rex Boake; Michael Lieber; Mostafa Elhilali; Jack Geller; Juliane Imperto-McGinely; Gerald L Andriole; Reginald C Bruskewitz; Patrick C Walsh; Georg Bartsch; John N Nacey; Sukrut Shah; Frances Pappas; Amy Ko; Thomas Cook; Elizabeth Stoner; Joanne Waldstreicher

2003-01-01

295

Immunohistochemical characterization of cellular proliferation in small intestinal hyperplasia of rats with hepatic Strobilocercus fasciolaris infection.  

PubMed

Rats infected with the larvae of Taenia taeniaeformis harbour the intermediate stage of the parasite Strobilocercus fasciolaris within the liver. Affected animals also develop gastric and intestinal hyperplasia. The pathogenesis of the gastric hyperplasia has been extensively investigated, but few studies have addressed the nature of the intestinal changes. This study characterizes the proliferation of small intestinal epithelial cells by immunohistochemical labelling for proliferating cell nuclear antigen (PCNA) and bromodeoxyuridine (BrdU) uptake. At 6 weeks post-infection (wpi) there was an increase in villous length but crypt depth was normal. At 9 wpi there was evidence of epithelial hyperplasia, increased villous length and crypt depth, and expansion of zones of epithelial proliferation. Immunohistochemical labelling indicated that an increase in the number of proliferating cells produced a greater number of progeny cells. Intestinal hyperplasia during experimental infection with T. taeniaeformis larvae is likely to be related to the associated gastropathy, although the mechanisms underlying both changes remain undefined. PMID:18539293

Lagapa, J T; Oku, Y; Kamiya, M

2008-07-01

296

Prenatal diagnosis of congenital adrenal hyperplasia: reliability of amniotic fluid steroid analysis  

Microsoft Academic Search

The concentration of 170H-progesterone was measured in amniotic fluid samples collected from 55 mothers who had previously had a child with congenital adrenal hyperplasia due to 21-hydroxylase deficiency. In eight pregnancies the levels of 170H-progesterone were raised; the parents elected to terminate in four and examinations of the fetus confirmed the diagnosis of congenital adrenal hyperplasia. In each case, the

I A Hughes; J Dyas; D Riad-Fahmy; K M Laurence

1987-01-01

297

The association between benign prostatic hyperplasia and chronic kidney disease in community-dwelling men  

Microsoft Academic Search

The association between benign prostatic hyperplasia and chronic kidney disease in community-dwelling men.BackgroundBenign prostatic hyperplasia (BPH) and chronic kidney disease are important public health problems in older men. Previous referral-based studies disagree on whether BPH is associated with chronic kidney disease. The objective of this study was to determine the community-based association between clinical measures of BPH and chronic kidney

Andrew D. Rule; Debra J. Jacobson; Rosebud O. Roberts; Cynthia J. Girman; Michaela E. McGree; Michael M. Lieber; Steven J. Jacobsen

2005-01-01

298

Predictive diagnosis of endometrial hyperplasia and personalized therapeutic strategy in women of fertile age  

PubMed Central

Introduction Endometrial hyperplasia has a high risk for malignant transformation and relapses; existing mini-invasive treatments may lead to irrevocable endometrium destruction. The aims were to analyze receptor systems in endometrial hyperplasia, to evaluate the capabilities of ultrasonography, sonoelastography for diagnosis and treatment control, and to develop treatment algorithm. Materials and methods We included 313 women (20–45 years), assessed into the following: group 1 (n?=?112) with glandular cystic hyperplasia, group 2 (n?=?98) endometrial polyps, and group 3 (n?=?103) atypical hyperplasia; and 82 controls who have undergone hysteroscopy before in vitro fertilization in tubal origin infertility were also included. Patients underwent clinical examination, transvaginal ultrasound, immunohistochemical study, and hormonal therapy/hysteroresectoscopy. Results In patients with glandular hyperplasia, we registered increase of endometrium estrogen receptors (75.6% in the epithelium and 30.9% in the stroma; in controls, 43.3% and 29.6%, respectively); in polyps, there was a significant estrogen receptor increase in the stroma (48.2% vs 29.6% in controls), and in atypical hyperplasia, progesterone receptors significantly increased in the stroma. Ki-67 increased (40% to 50%) in the epithelium without changes in the stroma. Ultrasound has a sensitivity of 96% and a specificity of 85% for early detection of endometrial pathology and prediction outcome of intervention, and sonoelastography has a sensitivity of 91% and a specificity of 83% for polyp diagnosis. Personalized treatment was effective in 88.8%, relapse was diagnosed in 11.2% after 6 months, and conservative treatment of atypical hyperplasia was effective in 45%: in 25.8%, ablative hysteroresectoscopy was performed, while in 22.6% with comorbidities, hystero/oophorectomies were performed. Conclusions The evaluation of receptor status with ultrasound data in patients with endometrial hyperplasia allows for a clear definition of the treatment policy, avoidance of relapse, treatment optimization, and observation of such patients. PMID:24314145

2013-01-01

299

The effects of Toradol on postoperative intimal hyperplasia in a rat carotid endarterectomy model: laboratory research.  

PubMed

Carotid endarterectomy (CEA) and more recently carotid artery stenting are the treatments of choice for atherosclerotic disease of the extracranial carotid arteries; however, early restenosis caused by neointimal hyperplasia confounds surgical therapy. Oxidative stress has been implicated in the progression of intimal hyperplasia. The authors hypothesized that ketorolac tromethamine (Toradol), a nonsteroidal antiinflammatory drug that is a potent cyclooxygenase inhibitor, would decrease oxidative stress and thereby reduce intimal hyperplasia in a rat CEA model. Twenty-nine male Sprague-Dawley rats underwent CEA and were divided into 3 treatment groups as follows: (1) control (placebo), (2) 7.5 mg/kg Toradol, and (3) 10 mg/kg Toradol. Toradol treatment began 2 days before CEA and continued for 2 weeks. Two weeks after endarterectomy, carotid arteries were fixed, harvested, and examined for platelet activity (platelet reactive units), oxidative stress (malondialdehyde and glutathione), and intimal hyperplasia (measured as percentage of luminal stenosis). Platelet activity, malondialdehyde and glutathione, and intimal hyperplasia were all significantly lowered in both 7.5- and 10-mg/kg doses of Toradol versus control. Toradol given daily beginning 2 days before CEA and ending 2 weeks after the procedure was effective at significantly reducing platelet activity, oxidative stress, and intimal hyperplasia development in the rat without any increase in bleeding. Although the mechanism of action of this reduction is not completely understood, one possible explanation may be through the inhibition of reactive oxygen species production. PMID:17942855

Kalapatapu, Venkat R; Satterfield, Leighton; Brown, Aliza T; Hongjiang Chen; Ercal, Nuran; Price, Tulin O; Jie Gao; Ibrahim, Khalil; Moursi, Mohammed M

2007-01-01

300

Effect of nitric oxide on neointimal hyperplasia based on sex and hormone status.  

PubMed

Nitric oxide (NO)-based therapies decrease neointimal hyperplasia; however, studies have been performed only in male animal models. Thus, we sought to evaluate the effect of NO on vascular smooth muscle cells (VSMC) in vitro and neointimal hyperplasia in vivo based on sex and hormone status. In hormone-replete medium, male VSMC proliferated at greater rates than female VSMC. In hormone-depleted medium, female VSMC proliferated at greater rates than male VSMC. However, in both hormone environments, NO inhibited proliferation and migration to a greater extent in male compared to female VSMC. These findings correlated with greater G?/G? cell cycle arrest and changes in cell cycle protein expression in male compared to female VSMC after exposure to NO. Next, the rat carotid artery injury model was used to assess the effect of NO on neointimal hyperplasia in vivo. Consistent with the in vitro data, NO was significantly more effective at inhibiting neointimal hyperplasia in hormonally intact males compared to females using weight-based dosing. An increased weight-based dose of NO in females was able to achieve efficacy equal to that in males. Surprisingly, NO was less effective at inhibiting neointimal hyperplasia in castrated animals of both sexes. In conclusion, these data suggest that NO inhibits neointimal hyperplasia more effectively in males compared to females and in hormonally intact compared to castrated rats, indicating that the effects of NO in the vasculature may be sex- and hormone-dependent. PMID:21256959

Hogg, Melissa E; Varu, Vinit N; Vavra, Ashley K; Popowich, Daniel A; Banerjee, Monisha N; Martinez, Janet; Jiang, Qun; Saavedra, Joseph E; Keefer, Larry K; Kibbe, Melina R

2011-05-01

301

Effect of Nitric Oxide on Neointimal Hyperplasia based on Sex and Hormone Status  

PubMed Central

Nitric oxide (NO)-based therapies decrease neointimal hyperplasia; however, studies have only been performed in male animal models. Thus, we sought to evaluate the effect of NO on vascular smooth muscle cells (VSMC) in vitro and neointimal hyperplasia in vivo based on sex and hormone status. In hormone-replete media, male VSMC proliferated at greater rates than female VSMC. In hormone-deplete media, female VSMC proliferated at greater rates than male VSMC. However, in both hormone environments, NO inhibited proliferation and migration to a greater extent in male versus female VSMC. These findings correlated with greater G0/G1 cell cycle arrest and changes in cell cycle protein expression in male versus female VSMC following exposure to NO. Next, the rat carotid artery injury model was performed to assess the effect of NO on neointimal hyperplasia in vivo. Consistent with the in vitro data, NO was significantly more effective at inhibiting neointimal hyperplasia in hormonally intact males versus females using weight-based dosing. An increased weight-based dose of NO in females was able to achieve efficacy equal to that in males. Surprisingly, NO was less effective at inhibiting neointimal hyperplasia in both sexes in castrated animals. In conclusion, these data suggest that NO inhibits neointimal hyperplasia more effectively in males than females and in hormonally-intact compared to castrated rats, indicating that the effect of NO in the vasculature may be sex- and hormone-dependent. PMID:21256959

Hogg, Melissa E.; Varu, Vinit N.; Vavra, Ashley K.; Popowich, Daniel A.; Banerjee, Monisha N.; Martinez, Janet; Jiang, Qun; Saavedra, Joseph E.; Keefer, Larry K.; Kibbe, Melina R.

2011-01-01

302

Tuberous sclerosis diagnosed by incidental computed tomography findings of multifocal micronodular pneumocyte hyperplasia: a case report  

PubMed Central

Introduction The majority of multifocal micronodular pneumocyte hyperplasia associated with tuberous sclerosis complex is diagnosed with the classical clinical triad of seizures, mental retardation, and skin lesions. We report a rare case of tuberous sclerosis complex with no classical clinical findings, which was diagnosed through incidental computed tomography findings of multiple nodular lesions of multifocal micronodular pneumocyte hyperplasia. Case presentation A chest computed tomography scan of a 51-year-old Japanese woman showed multiple nodular ground-glass opacities that were not seen on chest X-ray. Video-assisted thoracoscopic surgery was performed. A histological examination demonstrated type II pneumocyte hyperplasia with thickened fibrotic alveolar septa, which was consistent with multifocal micronodular pneumocyte hyperplasia. Brain magnetic resonance imaging displayed multiple cortical tubers, and abdominal computed tomography showed bilateral renal angiomyolipoma. Our patient was finally diagnosed as having tuberous sclerosis complex with multifocal micronodular pneumocyte hyperplasia, although she had no episodes of epilepsy, no skin lesions, and no family history. Conclusions Multifocal micronodular pneumocyte hyperplasia with latent tuberous sclerosis complex should be considered in the differential diagnosis of multiple ground-glass opacities. PMID:23072249

2012-01-01

303

Scaffold characterization using NLO multimodal microscopy in metrology for regenerative medicine  

NASA Astrophysics Data System (ADS)

Metrology in regenerative medicine aims to develop traceable measurement technologies for characterizing cellular and macromolecule behaviour in regenerative medicine products and processes. One key component in regenerative medicine is using three-dimensional porous scaffolds to guide cells during the regeneration process. The regeneration of specific tissues guided by tissue analogous substrates is dependent on diverse scaffold architectural properties that can be derived quantitatively from scaffolds images. This paper discuss the results obtained with the multimodal NLO microscope recently realized in our laboratory in characterizing 3D tissue engineered (TE) scaffolds colonized from human Mesenchimal stem cells (hMSC), focusing on the study of the three-dimensional metrological parameters.

Mortati, Leonardo; Divieto, Carla; Boffitto, Monica; Sartori, Susanna; Ciardelli, Gianluca; Sassi, Maria Paola

2013-09-01

304

Influence of spironolactone on neonatal screening for congenital adrenal hyperplasia  

PubMed Central

AIM—To determine if the diuretic spironolactone cross reacts with 17?-hydroxyprogesterone (17OHP) in an enzyme linked immunosorbent assay (ELISA) kit used for the mass screening of congenital adrenal hyperplasia.?METHODS—Concentrations of 17OHP on a blood filter paper disc were measured using an ELISA kit (kit C-7: ENZAPLATE N-17? -OHP-7; Chiron, Tokyo, Japan). The cross reactivity of spironolactone and its metabolites with 17OHP was determined. The concentrations of spironolactone and its metabolites in blood were measured using HPLC (high performance liquid chromatography).?RESULTS—Spironolactone cross reacted with 17OHP using kit C-7 (0.01%), by increasing 17OHP concentration in a dose dependent manner. The blood concentration of spironolactone and its metabolites was nearly 900 ng/ml, high enough to show an additive effect on the 17OHP concentration. About 12% of the false positive cases screened using the kit were due to the administration of spironolactone.?CONCLUSIONS—Spironolactone interferes with 17OHP concentrations, leading to false positive test results for CAH.?? PMID:10525019

Terai, I.; Yamano, K.; Ichihara, N.; Arai, J.; Kobayashi, K.

1999-01-01

305

Benign prostatic hyperplasia: An overview of existing treatment  

PubMed Central

Benign prostatic hyperplasia (BPH) is the most common condition in aging men, associated with lower urinary tract symptoms (LUTS). A better understanding of the prostate physiology, function, and pathogenesis has led to the development of promising agents, useful in the management of LUTS in men. The specific approach used to treat BPH depends upon number of factors like age, prostrate size, weight, prostate-specific antigen level, and severity of the symptoms. 5?-reductase inhibitors decrease the production of dihydrotestosterone within the prostate, which results in decreased prostate volume, increased peak urinary flow rate, improvement of symptoms, decreased risk of acute urinary retention, and need for surgical intervention. ?1-adrenergic receptor (?1-AR) antagonists decrease LUTS and increase urinary flow rates in men with symptomatic BPH, but do not reduce the long-term risk of urinary retention or need for surgical intervention. Clinical efficacy of either 5?-reductase inhibitor or ?1-AR antagonist has been further improved by using combination therapy; however, long-term outcomes are still awaited. Many more potential new therapies are under development that may improve the treatment of BPH. This article gives a brief account of rationale and efficacy of different treatment options presently available in the management of BPH. PMID:21455413

Dhingra, Neelima; Bhagwat, Deepak

2011-01-01

306

Multifocal adenomatous oncocytic hyperplasia of the parotid gland.  

PubMed

Multifocal adenomatous oncocytic hyperplasia (MAOH) is a non-neoplastic lesion that is classified as oncocytosis. MAOH is a rare entity of the parotid gland and accounts for approximately 0.1% of salivary gland lesions. Here, we report a case of MAOH of the parotid gland. The patient was a 71-year-old woman who presented with discomfort at the left side of her neck. Fine-needle aspiration cytology of the parotid gland revealed a loose sheet-like cluster of round to polygonal cells with granular cytoplasm against a hemorrhagic background. The cells had round to oval, centrally located nuclei with granular chromatin and without distinct nucleoli. Histologically, the lesion was formed of many variable-sized nodules, comprising oncocyte-like cells with small round nuclei and eosinophilic granular cytoplasm that was positive for mitochondrial antibodies. The diagnosis of MAOH is difficult to make by cytology alone, because the findings overlap with those of other oncocytic lesions. In particular, the cytological findings of MAOH have not been sufficiently reported to date. A correlation of cytology and histology was expected. PMID:25580104

Kinoshita, Yuichi; Harada, Hiroshi; Kobayashi, Tadao K; Yoshizawa, Katsuhiko; Yuri, Takashi; Takasu, Kosho; Tsubura, Airo; Shikata, Nobuaki

2014-09-01

307

Multifocal Adenomatous Oncocytic Hyperplasia of the Parotid Gland  

PubMed Central

Multifocal adenomatous oncocytic hyperplasia (MAOH) is a non-neoplastic lesion that is classified as oncocytosis. MAOH is a rare entity of the parotid gland and accounts for approximately 0.1% of salivary gland lesions. Here, we report a case of MAOH of the parotid gland. The patient was a 71-year-old woman who presented with discomfort at the left side of her neck. Fine-needle aspiration cytology of the parotid gland revealed a loose sheet-like cluster of round to polygonal cells with granular cytoplasm against a hemorrhagic background. The cells had round to oval, centrally located nuclei with granular chromatin and without distinct nucleoli. Histologically, the lesion was formed of many variable-sized nodules, comprising oncocyte-like cells with small round nuclei and eosinophilic granular cytoplasm that was positive for mitochondrial antibodies. The diagnosis of MAOH is difficult to make by cytology alone, because the findings overlap with those of other oncocytic lesions. In particular, the cytological findings of MAOH have not been sufficiently reported to date. A correlation of cytology and histology was expected. PMID:25580104

Kinoshita, Yuichi; Harada, Hiroshi; Kobayashi, Tadao K.; Yoshizawa, Katsuhiko; Yuri, Takashi; Takasu, Kosho; Tsubura, Airo; Shikata, Nobuaki

2014-01-01

308

c-Kit signaling determines neointimal hyperplasia in arteriovenous fistulae.  

PubMed

Stenosis of arteriovenous (A-V) fistulae secondary to neointimal hyperplasia (NIH) compromises dialysis delivery, which worsens patients' quality of life and increases medical costs associated with the maintenance of vascular accesses. In the present study, we evaluated the role of the receptor tyrosine kinase c-Kit in A-V fistula neointima formation. Initially, c-Kit was found in the neointima and adventitia of human brachiobasilic fistulae, whereas it was barely detectable in control veins harvested at the time of access creation. Using the rat A-V fistula model to study venous vascular remodeling, we analyzed the spatial and temporal pattern of c-Kit expression in the fistula wall. Interestingly, c-Kit immunoreactivity increased with time after anastomosis, which concurred with the accumulation of cells in the venous intima. In addition, c-Kit expression in A-V fistulae was positively altered by chronic kidney failure conditions. Both blockade of c-Kit with imatinib mesylate (Gleevec) and inhibition of stem cell factor production with a specific short hairpin RNA prevented NIH in the outflow vein of experimental fistulae. In agreement with these data, impaired c-Kit activity compromised the development of NIH in A-V fistulae created in c-KitW/Wv mutant mice. These results suggest that targeting of the c-Kit signaling pathway may be an effective approach to prevent postoperative NIH in A-V fistulae. PMID:25186298

Skartsis, Nikolaos; Martinez, Laisel; Duque, Juan Camilo; Tabbara, Marwan; Velazquez, Omaida C; Asif, Arif; Andreopoulos, Fotios; Salman, Loay H; Vazquez-Padron, Roberto I

2014-11-01

309

Morphological Changes of Benign Prostatic Hyperplasia in Culture  

PubMed Central

A technique is described for the culture of slices of benign prostatic hyperplasia (BPH) for periods of a week in organ culture. Under these conditions tissue repair took place, resulting in a covering layer of transitional epithelium which formed around the explant and spread out laterally as a monolayer. Autoradiography and studies with [3H]thymidine uptake suggested that the repair activity, which reached a peak at Day 3 in culture, was the centre of biochemical activity, overshadowing that of the rest of the explant. Necrosis of the explant base tended to develop abruptly during the first day of culture but thereafter remained stable. The epithelium was well preserved morphologically, but explant acid phosphatase activity fell progressively. No morphological response to testosterone (10-5 mol/l) or stilboestrol diphosphate (10-5 mol/l) was seen. Attention is drawn to a possible source of misinterpretation of results offered by the uptake of [3H]thymidine into DNA in organ culture. ImagesFig. 5Fig. 6Fig. 10Fig. 11Fig. 3Fig. 4Fig. 12Fig. 13Fig. 1 PMID:4121823

McMahon, M. J.; Thomas, G. H.

1973-01-01

310

Diagnosis and management of benign prostatic hyperplasia in primary care  

PubMed Central

Benign prostatic hyperplasia (BPH), and its clinical manifestation as lower urinary tract symptoms (LUTS), is a major health concern for aging men. There have been significant advances in the diagnosis and treatment of BPH in recent years. There has been a renewed interest in medical therapies and less invasive surgical techniques. As a consequence, the treatment needs of men with mild to moderate LUTS without evidence of prostate cancer can now be accomplished in a primary care setting. There are differences in the way urologists and primary care physicians approach the evaluation and management of LUTS due to BPH, which is not reflected in Canadian Urological Association (CUA) and American Urological Association (AUA) guidelines. A “shared care” approach involving urologists and primary care physicians represents a reasonable and viable model for the care of men suffering from LUTS. The essence of the model centres around educating and communicating effectively with the patient on BPH. This article provides primary care physicians with an overview of the diagnostic and management strategies outlined in recent CUA and AUA guidelines so that they may be better positioned to effectively deal with this patient population. It is now apparent that we must move away from the urologist as the first-line physician, and allow primary care physicians to accept a new role in the diagnosis and management of BPH. PMID:19543429

Tanguay, Simon; Awde, Murray; Brock, Gerald; Casey, Richard; Kozak, Joseph; Lee, Jay; Nickel, J. Curtis; Saad, Fred

2009-01-01

311

Giant Bilateral Adrenal Myelolipoma with Congenital Adrenal Hyperplasia  

PubMed Central

Myelolipomas are rare and benign neoplasms, predominant of the adrenal glands, consisting of adipose and mature hematopoietic tissue, commonly discovered incidentally with increased use of radiologic imaging. Few cases of giant bilateral adrenal masses are reported, especially in the setting of congenital adrenal hyperplasia (CAH). We report the case of a 39-year-old male with a history of CAH secondary to 21-? hydroxylase deficiency on steroids since childhood, self-discontinued during adolescence, presenting with abdominal distension, fatigue, decreased libido, and easy bruising. Imaging revealed giant bilateral adrenal masses. He subsequently underwent bilateral adrenalectomy found to be myelolipomas measuring 30 × 25 × 20?cm on the left and weighing 4.1?kg and 25 × 20 × 13?cm on the right and weighing 2.7?kg. Adrenal myelolipomas are found to coexist with many other conditions such as Cushing's syndrome, Addison's disease, and CAH. We discuss the association with high adrenocorticotropic hormone (ACTH) states and review the studies involving ACTH as proponent leading to myelolipomas. Massive growth of these tumors, as in our case, can produce compression and hemorrhagic symptoms. We believe it is possible that self-discontinuation of steroids, in the setting of CAH, may have resulted in the growth of his adrenal masses. PMID:25140269

Al-Bahri, S.; Tariq, A.; Lowentritt, B.; Nasrallah, D. V.

2014-01-01

312

Role of laser therapy in benign prostate hyperplasia (BPH)  

NASA Astrophysics Data System (ADS)

Benign prostatic hyperplasia (BPH) is a common disease in males older than 50 years of age. 75-80% of this population is considered to have some degree of BPH causing clinical symptoms and requiring urological treatment. Transurethral resection of the prostate (TUR-P) is currently the standard surgical treatment modality for BPH. In an attempt to minimize the need for hospitalization and the associated perioperative and postoperative morbidity, alternatives have been sought. Various types of laser techniques such as interstitial laser coagulation and side-firing technology have been proposed. Numerous studies have shown that laser procedures safely and effectively reduce the volume of the prostate. Intra- and postoperative bleeding are nearly unknown complications for laser procedures, whereas this is the most relevant complication for the TUR-P. Due to significant tissue edema after laser treatment, patients commonly show delayed time to void adequately and, therefore, catheter drainage is often necessary for 3 to 21 days. Retrograde ejaculation is reported to occur less (0- 10%) compared to TUR-P (greater than 60%). Urinary tract infections are very common after interstitial laser coagulation. Although not many long-term clinical data are available, various studies have shown that BPH patients improve in symptom score, flow rate and post-void residual up to 3 years after laser treatment. This paper presents a concise review of efficacy, advantages and disadvantages of the most frequently used laser techniques as well as the long-term clinical data compared to TUR-P.

de Riese, Werner T.; Sharpe, Brent A.; Aronoff, David B.; Mittemeyer, Bernhard T.

2001-05-01

313

Taenia taeniaeformis: colonic hyperplasia in heavily infected rats.  

PubMed

Only one study previously mentioned the involvement of colon during Taenia taeniaeformis larvae infection in rats with inconsistent occurrence of lesions. Present study aimed to determine the consistency of histopathologic changes in colonic epithelia, and the proliferation of mucosal cells through BrdU and PCNA immunohistochemistry. Results demonstrated that crypt hyperplasia of the colon was found in all infected rats, although variable in degree even in a single tissue section. Cystic cavities were frequently seen in severely hyperplastic mucosa. Proliferative zone lengths were significantly increased and PCNA positive cells were observed throughout the colonic crypt lengths at 9 but not at 6 weeks post infection. Cell proliferation involving the major types of cells in the epithelial colon was also increased in infected rats at 9 weeks post infection, with labeling indices significantly greater than the control rats throughout the BrdU time course labeling. Findings suggested that massive increases in epithelial cells and depth of colonic crypts were due to a remarkable increase in cell proliferation. The study concluded that enteropathy in the colon during T. taeniaeformis infection could be consistently observed in heavily infected rats. PMID:18793638

Lagapa, Jose Trinipil; Oku, Yuzaburo; Kamiya, Masao

2008-12-01

314

Oxidative stress in patients with benign prostate hyperplasia.  

PubMed

Benign Prostate Hyperplasia (BPH) is a common health problem in aging male. Free radicals and Reactive Oxygen Species (ROS) are produced in overwhelming quantity with advancement of age. When in oxidative stress, these reactive species cause extensive damage to various organ in the body, may be associated with pathogenesis of BPH also. This study aimed at assessing Malondialdehyde (MDA), the marker of lipid peroxidation and anti-oxidants e.g. alpha-Tocopherol and Ascorbate status in plasma in BPH patients. Forty eight (n=48) cases of BPH and forty six (n = 46) healthy age matched controls were enrolled. Plasma MDA level showed 4.81+/-1.87 nmol/ml in cases compared to 3.69+/-1.56 nmol/ml in healthy controls (p<0.001). There were significant decrease in plasma alpha-Tocopherol and ascorbate level which were 0.85+/-0.12 mg/dl and 0.93 +/- 0.13 mg/dl in cases compared to 1.37+/-0.31 mg/dl and 1.44+/-0.38 mg/dl in healthy controls respectively. Inverse correlation of plasma MDA with alpha-Tocopherol (r = -0.09, p>0.05) and Ascorbate (r =-0.51, p=0.008) was found in BPH patients. There was mild elevation of PSA in BPH patients compared with control but was not statistically significant. Thus, our study showed the evidence of association of oxidative stress in BPH patients. PMID:18274564

Aryal, M; Pandeya, A; Bas, B K; Lamsal, M; Majhi, S; Pandit, R; Agrawal, C S; Gautam, N; Baral, N

2007-01-01

315

TMJ function after partial condylectomy in active mandibular condylar hyperplasia  

PubMed Central

Condylar hyperplasia is a frequent pathology that causes severe facial asymmetries. The partial condylectomy generally halts the disease. The aim of this research was to examine post-condylectomy TMJ function; 14 patients were included in this study, 6 male and 8 female. The average age was 21 years old. In all, the partial condylectomy was performed with preauricular or endaural access and the osteotomy were performed with drills, saw or an ultrasonic system. The patients were assessed with 3 or more time after surgery and were considering maximum mouth opening, right and left lateralities, presence of pain, noises, alterations in the facial nerve (VII) and esthetic alteration from the scar. The analysis was performed with the visual analog scale (VAS) and with a 7 cm metallic rule. Data analysis was descriptive plus chi-square test considering p value < 0.05 for statistical differences. With an average of 11 month after surgery, the results showed that the open mouth (over 35 mm) and lateralities (average 9 mm for the both right and left side) were normal and without statistical differences between the right or left side. Noise was observed in 3 patients and pain was observed in two patients with level 2 and 1 (VAS score). Scar was not related to problem with patient and the temporal branch of facial nerve was observed with limitations but without problem for patients. It can be concluded that the condylectomy is a safe and effective procedure with low morbidity for patients. PMID:24753777

Olate, Sergio; Martinez, Felipe; Uribe, Francisca; Pozzer, Leandro; Cavalieri-Pereira, Lucas; de Moraes, Marcio

2014-01-01

316

Wound Healing Versus Regeneration: Role of the Tissue Environment in Regenerative Medicine  

E-print Network

One of the major challenges in the field of regenerative medicine is how to optimize tissue regeneration in the body by therapeutically manipulating its natural ability to form scar at the time of injury or disease. It is ...

Atala, Anthony

317

Cell Microenvironment Engineering and Monitoring for Tissue Engineering and Regenerative Medicine: The Recent Advances  

E-print Network

In tissue engineering and regenerative medicine, the conditions in the immediate vicinity of the cells have a direct effect on cells’ behaviour and subsequently on clinical outcomes. Physical, chemical, and biological ...

Barthes, Julien

318

Definition study for an extended manned test of a regenerative life support system, preliminary test plan  

NASA Technical Reports Server (NTRS)

A preliminary plan and procedure are presented for conducting an extended manned test program for a regenerative life support system. Emphasis will be placed on elements associated with long-term system operation and long-term uninterrupted crew confinement.

1971-01-01

319

Bioluminescence regenerative cycle (BRC) system: Theoretical considerations for nucleic acid quantification assays  

E-print Network

Bioluminescence regenerative cycle (BRC) system: Theoretical considerations for nucleic acid Abstract A novel application of bioluminescence for nucleic acid quantification, the bioluminescence: Chemiluminescence; Bioluminescence; Gene expression; Nucleic acid; Polymerization; Enzyme kinetics; Positive

Hassibi, Arjang

320

Extracellular matrix considerations for scar-free repair and regeneration: Insights from regenerative diversity among vertebrates.  

PubMed

The extracellular matrix (ECM) is an essential feature of development, tissue homeostasis and recovery from injury. How the ECM responds dynamically to cellular and soluble components to support the faithful repair of damaged tissues in some animals but leads to the formation of acellular fibrotic scar tissue in others has important clinical implications. Studies in highly regenerative organisms such as the zebrafish and the salamander have revealed a specialist formulation of ECM components that support repair and regeneration, while avoiding scar tissue formation. By comparing a range of different contexts that feature scar-less healing and full regeneration vs. scarring through fibrotic repair, regenerative therapies that incorporate ECM components could be significantly enhanced to improve both regenerative potential and functional outcomes. This article is part of a directed issue entitled: Regenerative Medicine: the challenge of translation. PMID:25450455

Godwin, James; Kuraitis, Drew; Rosenthal, Nadia

2014-10-18

321

Fuzzy logic electric vehicle regenerative antiskid braking and traction control system  

DOEpatents

An regenerative antiskid braking and traction control system using fuzzy logic for an electric or hybrid vehicle having a regenerative braking system operatively connected to an electric traction motor, and a separate hydraulic braking system includes sensors for monitoring present vehicle parameters and a processor, responsive to the sensors, for calculating vehicle parameters defining the vehicle behavior not directly measurable by the sensor and determining if regenerative antiskid braking control, requiring hydraulic braking control, and requiring traction control are required. The processor then employs fuzzy logic based on the determined vehicle state and provides command signals to a motor controller to control operation of the electric traction motor and to the brake controller to control fluid pressure applied at each vehicle wheel to provide the appropriate regenerative braking control, hydraulic braking control, and traction control.

Cikanek, Susan R. (Wixom, MI)

1994-01-01

322

An Optical DIfferentiator Based on a Regenerative Amplifier with an Intracavity Tunable Volume Bragg Grating Filter  

SciTech Connect

An optical differentiator based on a regenerative amplifier with temperature-tuned volume Bragg grating as an intracavity spectral filter is demonstrated for the first time. Its applications for temporal contrast enhancement and other areas are discussed.

Okishev, A.V.; Smirnov, V.I.; Glebov, L.B.; Zuegel, J.D.

2008-04-08

323

Soy Protein Scaffold Biomaterials for Tissue Engineering and Regenerative Medicine  

NASA Astrophysics Data System (ADS)

Developing functional biomaterials using highly processable materials with tailorable physical and bioactive properties is an ongoing challenge in tissue engineering. Soy protein is an abundant, natural resource with potential use for regenerative medicine applications. Preliminary studies show that soy protein can be physically modified and fabricated into various biocompatible constructs. However, optimized soy protein structures for tissue regeneration (i.e. 3D porous scaffolds) have not yet been designed. Furthermore, little work has established the in vivo biocompatibility of implanted soy protein and the benefit of using soy over other proteins including FDA-approved bovine collagen. In this work, freeze-drying and 3D printing fabrication processes were developed using commercially available soy protein to create porous scaffolds that improve cell growth and infiltration compared to other soy biomaterials previously reported. Characterization of scaffold structure, porosity, and mechanical/degradation properties was performed. In addition, the behavior of human mesenchymal stem cells seeded on various designed soy scaffolds was analyzed. Biological characterization of the cell-seeded scaffolds was performed to assess feasibility for use in liver tissue regeneration. The acute and humoral response of soy scaffolds implanted in an in vivo mouse subcutaneous model was also investigated. All fabricated soy scaffolds were modified using thermal, chemical, and enzymatic crosslinking to change properties and cell growth behavior. 3D printing allowed for control of scaffold pore size and geometry. Scaffold structure, porosity, and degradation rate significantly altered the in vivo response. Freeze-dried soy scaffolds had similar biocompatibility as freeze-dried collagen scaffolds of the same protein content. However, the soy scaffolds degraded at a much faster rate, minimizing immunogenicity. Interestingly, subcutaneously implanted soy scaffolds affected blood glucose and insulin sensitivity levels. Furthermore, soy scaffolds implanted in the intraperitoneal cavity attached to adjacent liver tissue with no abnormalities. In vitro, soy scaffolds supported hMSC viability and transdifferentiation into hepatocyte-like cells. These results support the use of soy scaffolds for liver tissue engineering and for treating metabolic diseases. Based on achievable structural and mechanical properties, as well as systemic effects of ingested and degraded soy proteins, soy protein scaffolds may serve as new multifunctional biomaterials for tissue engineering and regenerative medicine.

Chien, Karen B.

324

Feeding and healing the world: through regenerative agriculture and permaculture.  

PubMed

The study of soil is a mature science, whereas related practical methods of regenerative agriculture and permaculture are not. However, despite a paucity of detailed peer reviewed research published on these topics, there is overwhelming evidence both that the methods work and they may offer the means to address a number of prevailing environmental challenges, e.g. peak oil, climate change, carbon capture, unsustainable agriculture and food shortages, peak phosphorus (phosphate), water shortages, environmental pollution, desert reclamation, and soil degradation. What is lacking is a proper scientific study, made in hand with actual development projects. By elucidating the scientific basis of these remarkable phenomena, we may obtain the means for solving some of the otherwise insurmountable problems confronting humanity, simply by observing, and working with, the patterns and forces of nature. This article is intended as a call to arms to make serious investment in researching and actualising these methods on a global scale. Despite claims that peak oil is no longer a threat because vast resources of gas and shale oil (tight oil) can now be recovered by fracking (hydraulic fracturing) combined with horizontal drilling, the reality is that proven actual reserves are only adequate to delay the peak by a few years. Furthermore, because of the rapid depletion rates of flow from gas wells and oil wells that are accessed by fracking, it will be necessary to drill continuously and relentlessly to maintain output, and there are material limits of equipment, technology and trained personnel to do this. Moreover, to make any sensible difference to the liquid fuel crisis, which is the most immediate consequence of peak oil, it would be necessary to convert the worlds one billion vehicles to run on natural gas rather than liquid fuels refined from crude oil, and this would take some considerable time and effort. The loss of widespread personalised transportation is thus inevitable and imminent, meaning a loss of globalised civilisation and a mandatory return to living in smaller localised communities. Permaculture and regenerative agriculture offer potentially the means to provide food and materials on the small scale, and address the wider issues of carbon emissions, and resource shortages. Since over half the World's population lives in cities, it seems likely that strengthening the resilience of these environments, using urban permaculture, may be a crucial strategy in achieving a measured descent in our use of energy and other resources, rather than an abrupt collapse of civilization. PMID:23469709

Rhodes, Christopher J

2012-01-01

325

An analysis of the regenerative expansion cycle in multi-component hydrocarbon separation systems  

E-print Network

AN ANALYSIS OF THE REGENERATIVE EXPANSION CYCLE IN MULTI-COMPONENT HYDROCARBON SEPARATION SYSTEMS A Thesis by John Leroy Horton Submitted to the Graduate College of the Texas A Sc M University in partial fulfillment of the requirements... for the professional degree of MECHANICAL ENGINEER MAY 1966 MAJOR SUBJECT - MECHANICAL ENGINEERING AN ANALYSIS OF THE REGENERATIVE EXPANSION CYCLE IN MULTI-COMPONENT HYDROCARBON SEPARATION SYSTEMS A Thesis by John Leroy Horton Approved as to style and content...

Horton, John Leroy

2012-06-07

326

Ti:sapphire regenerative amplifier for ultrashort high-power multikilohertz pulses without an external stretcher  

SciTech Connect

We report a simple and robust Ti:sapphire regenerative amplifier without prepulse stretching. Pulse stretching by positive group-velocity dispersion and negative third-order dispersion are provided by highly dispersive flint glass prisms inside the regenerative amplifier cavity. Using a single-grating compressor, we obtain transform-limited 60-fs Gaussian pulses at up to a 5-kHz repetition rate with energy of 50 {mu}J/pulse.

Joo, T.; Jia, Y.; Fleming, G.R. [Department of Chemistry and The James Franck Institute, The University of Chicago, Chicago, Illinois 60637 (United States)

1995-02-15

327

Highly Stable, All-Solid-State Nd:YLF Regenerative Amplifier  

SciTech Connect

A diode-pumped Nd:YLF regenerative amplifier (regen) has been developed and is in use in the 60-beam, 30-kJUV OMEGA laser system's driver line. The high stability, compactness, and reliability of this all-solid-state modular design are the key features of this concept. Stable, millijoule-level output-pulse energies with an overall gain of 109 have been demonstrated.

Okishev,A.V.; Zuegel,J.D.

2004-11-20

328

A survey of attitude and opinions of endodontic residents towards regenerative endodontics  

PubMed Central

Aim: The objective of this survey was to study the level of awareness, current state of knowledge and opinions towards regenerative endodontic treatments amongst the endodontic residents of India. Settings and Design: Questionnaire based survey was designed. Materials and Methods: After approval from the organizing committee of 26th Federation of Operative Dentistry of India and 19th Indian Endodontic Society National conference 2011, 200 copies of the questionnaire were circulated amongst the endodontic residents in conservative dentistry and endodontics at various colleges across the country about regenerative endodontic procedures. The survey included profile of the respondents and consisted of 23 questions about their knowledge, attitude and opinions regarding use of these procedures as part of future dental treatment. Results: The survey showed that half the participants (50.6%) had received continued education in stem cells and/or regenerative dental treatments. The majority of participants were of the opinion (86.6%) that regenerative therapy should be incorporated into dentistry, and most of them (88%) were willing to acquire training in learning this new treatment strategy. The results indicated that half of the participants (52.6%) were already using some type of regenerative therapy in their clinical practice; however, with a majority of these limited to use of membranes, scaffolds or bioactive materials. Conclusions: These results reflect that endodontic residents are optimistic about the use of regenerative endodontic procedures; however, a need for more research and training was felt. PMID:23956532

Utneja, Shivani; Nawal, Ruchika Roongta; Ansari, Mohammed Irfan; Talwar, Sangeeta; Verma, Mahesh

2013-01-01

329

Regenerative braking systems with torsional springs made of carbon nanotube yarn  

NASA Astrophysics Data System (ADS)

The demonstration of large stroke, high energy density and high power density torsional springs based on carbon nanotube (CNT) yarns is reported, as well as their application as an energy-storing actuator for regenerative braking systems. Originally untwisted CNT yarn is cyclically loaded and unloaded in torsion, with the maximum rotation angle increasing until failure. The maximum extractable energy density is measured to be as high as 6.13 kJ/kg. The tests also reveal structural reorganization and hysteresis in the torsional loading curves. A regenerative braking system is built to capture the kinetic energy of a wheel and store it as elastic energy in twisted CNT yarns. When the yam's twist is released, the stored energy reaccelerates the wheel. The measured energy and mean power densities of the CNT yarns in the simple regenerative braking system are up to 4.69 kJ/kg and 1.21 kW/kg, respectively. A slightly lower energy density of up to 1.23 kJ/kg and a 0.29 kW/kg mean power density are measured for the CNT yarns in a more complex system that mimics a unidirectional rotating regenerative braking mechanism. The lower energy densities for CNT yarns in the regenerative braking systems as compared with the yarns themselves reflect the frictional losses of the regenerative systems.

Liu, S.; Martin, C.; Lashmore, D.; Schauer, M.; Livermore, C.

2014-11-01

330

Restoration of anterior regeneration in a planarian with limited regenerative ability.  

PubMed

Variability of regenerative potential among animals has long perplexed biologists. On the basis of their exceptional regenerative abilities, planarians have become important models for understanding the molecular basis of regeneration. However, planarian species with limited regenerative abilities are also found. Despite the importance of understanding the differences between closely related, regenerating and non-regenerating organisms, few studies have focused on the evolutionary loss of regeneration, and the molecular mechanisms leading to such regenerative loss remain obscure. Here we examine Procotyla fluviatilis, a planarian with restricted ability to replace missing tissues, using next-generation sequencing to define the gene expression programs active in regeneration-permissive and regeneration-deficient tissues. We found that Wnt signalling is aberrantly activated in regeneration-deficient tissues. Notably, downregulation of canonical Wnt signalling in regeneration-deficient regions restores regenerative abilities: blastemas form and new heads regenerate in tissues that normally never regenerate. This work reveals that manipulating a single signalling pathway can reverse the evolutionary loss of regenerative potential. PMID:23883929

Sikes, James M; Newmark, Phillip A

2013-08-01

331

A dual function of copper in designing regenerative implants.  

PubMed

The supply of titanium implants which are widely used in orthopaedics with both regenerative and anti-microbial properties will achieve a great progress in bone regeneration. We asked, whether by appropriate concentrations of copper ions it will be possible both to inhibit growth of bacteria and stimulate biological responses in mesenchymal stem cells (MSC). Using titanium material which released galvanically deposited copper at concentrations from 0.3 to 1.75 mM, growth of planktonic Staphylococcus aureus was blocked and more importantly adherent bacteria were cleared from the material surface within 24 h. To test biological responses of human bone marrow derived MSC due to copper ions, we found that copper stimulated the proliferation of MSC in a narrow concentration range around 0.1 mM. Similar copper concentrations enhanced osteogenic differentiation of MSC when cells were cultured in osteogenic differentiation medium. We observed increased activity of alkaline phosphatase (ALP), higher expression of collagen I, osteoprotegerin, osteopontin and finally mineralization of the cells. We conclude that titanium implants that release copper ions can be effective against bacterial infections at higher concentrations of copper near the implant surface and can promote bone regeneration when its concentration becomes lower due to diffusion. PMID:25617124

Burghardt, Ines; Lüthen, Frank; Prinz, Cornelia; Kreikemeyer, Bernd; Zietz, Carmen; Neumann, Hans-Georg; Rychly, Joachim

2015-03-01

332

Satellite cells from dystrophic muscle retain regenerative capacity.  

PubMed

Duchenne muscular dystrophy is an inherited disorder that is characterized by progressive skeletal muscle weakness and wasting, with a failure of muscle maintenance/repair mediated by satellite cells (muscle stem cells). The function of skeletal muscle stem cells resident in dystrophic muscle may be perturbed by being in an increasing pathogenic environment, coupled with constant demands for repairing muscle. To investigate the contribution of satellite cell exhaustion to this process, we tested the functionality of satellite cells isolated from the mdx mouse model of Duchenne muscular dystrophy. We found that satellite cells derived from young mdx mice contributed efficiently to muscle regeneration within our in vivo mouse model. To then test the effects of long-term residence in a dystrophic environment, satellite cells were isolated from aged mdx muscle. Surprisingly, they were as functional as those derived from young or aged wild type donors. Removing satellite cells from a dystrophic milieu reveals that their regenerative capacity remains both intact and similar to satellite cells derived from healthy muscle, indicating that the host environment is critical for controlling satellite cell function. PMID:25460248

Boldrin, Luisa; Zammit, Peter S; Morgan, Jennifer E

2015-01-01

333

Regenerative Endodontics in light of the stem cell paradigm  

PubMed Central

Stem cells play a critical role in development and in tissue regeneration. The dental pulp contains a small sub-population of stem cells that are involved in the response of the pulp to caries progression. Specifically, stem cells replace odontoblasts that have undergone cell death as a consequence of the cariogenic challenge. Stem cells also secrete factors that have the potential to enhance pulp vascularization and provide the oxygen and nutrients required for the dentinogenic response that is typically observed in teeth with deep caries. However, the same angiogenic factors that are required for dentin regeneration may ultimately contribute to the demise of the pulp by enhancing vascular permeability and interstitial pressure. Recent studies focused on the biology of dental pulp stem cells revealed that the multipotency and angiogenic capacity of these cells could be exploited therapeutically in dental pulp tissue engineering. Collectively, these findings suggest new treatment paradigms in the field of Endodontics. The goal of this review is to discuss the potential impact of dental pulp stem cells to Regenerative Endodontics. PMID:21726222

Rosa, Vinicius; Botero, Tatiana M.; Nör, Jacques E.

2013-01-01

334

Harnessing the potential of lung stem cells for regenerative medicine.  

PubMed

In response to recurrent exposure to environmental insults such as allergens, pollution, irritants, smoke and viral/bacterial infection, the epithelium of the lung is continually damaged. Homeostasis of the lung requires a balance between immune regulation and promotion of tissue regeneration, which requires the co-ordinated proliferation and differentiation of stem and progenitor cells. In this review we reflect on the current understanding of lung epithelial stem and progenitor cells and advocate a model hierarchy in which self-renewing multipotent lung epithelial stem cells give rise to lineage restricted progenitor cells that repopulate airway and alveolar epithelial cell lineages during homeostasis and repair. We also discuss the role of mesenchymal progenitor cells in maintaining the structural integrity of the lung and propose a model in which mesenchymal cells act as the quintessential architects of lung regeneration by providing molecular signals, such as FGF-10, to regulate the fate and specificity of epithelial stem and progenitor cells. Moreover, we discuss the current status and future prospects for translating lung stem cell therapies to the clinic to replace, repair, or regenerate diseased lung tissue. This article is part of a directed issue entitled: Regenerative Medicine: the challenge of translation. PMID:25450456

McQualter, Jonathan L; Anthony, Desiree; Bozinovski, Steven; Prêle, Cecilia M; Laurent, Geoffrey J

2014-11-01

335

The Mouse Median Nerve Experimental Model in Regenerative Research  

PubMed Central

Sciatic nerve crush injury in rat animal model is one of the most common experimental models used in regenerative research. However, the availability of transgenic mouse for nerve regeneration studies is constantly increasing and, therefore, the shift from rat model to mouse model is, in some cases, necessary. Moreover, since most of the human nerve lesions occur in the upper limb, it is also advantageous to shift from sciatic nerve to median nerve. In this study we described an experimental model which involves lesions of the median nerve in the mouse. Data showed that the finger flexor muscle contraction strength, assessed to evaluate the motor function recovery, and reached values not different from the control already 20 days after injury. The degree of nerve regeneration evaluated with stereological methods in light microscopy showed that, 25 days after injury, the number of regenerated myelinated fibers was comparable to the control, but they were smaller with a thinner myelin thickness. Stereological analysis made in electron microscopy confirmed these results, although the total number of fibers quantified was significantly higher compared to light microscopy analysis, due to the very small size of some fibers that can be detected only in electron microscopy. PMID:25180190

Buskbjerg Jager, Sara

2014-01-01

336

Thermal Inkjet Printing in Tissue Engineering and Regenerative Medicine  

PubMed Central

With the advantages of high throughput, digital control, and highly accurate placement of cells and biomaterial scaffold to the desired 2D and 3D locations, bioprinting has great potential to develop promising approaches in translational medicine and organ replacement. The most recent advances in organ and tissue bioprinting based on the thermal inkjet printing technology are described in this review. Bioprinting has no or little side effect to the printed mammalian cells and it can conveniently combine with gene transfection or drug delivery to the ejected living systems during the precise placement for tissue construction. With layer-by-layer assembly, 3D tissues with complex structures can be printed using scanned CT or MRI images. Vascular or nerve systems can be enabled simultaneously during the organ construction with digital control. Therefore, bioprinting is the only solution to solve this critical issue in thick and complex tissues fabrication with vascular system. Collectively, bioprinting based on thermal inkjet has great potential and broad applications in tissue engineering and regenerative medicine. This review article introduces some important patents related to bioprinting living systems and the bioprinting in tissue engineering field. PMID:22436025

Cui, Xiaofeng; Boland, Thomas; D’Lima, Darryl D.; Lotz, Martin K.

2013-01-01

337

Therapeutic Lymphangiogenesis With Implantation of Adipose?Derived Regenerative Cells  

PubMed Central

Background Lymphedema is one of the serious clinical problems that can occur after surgical resection of malignant tumors such as breast cancer or intra?pelvic cancers. However, no effective treatment options exist at present. Here, we report that implantation of adipose?derived regenerative cells (ADRCs) can induce lymphangiogenesis in a mouse model of reparative lymphedema. Methods and Results ADRCs were isolated from C57BL/6J mice. To examine the therapeutic efficacy of ADRC implantation in vivo, we established a new mouse model of tail lymphedema. Lymphedema was improved significantly by local injection of ADRCs (P<0.05). Histological analysis revealed that lymphatic capillary density was greater in the ADRC group than in the phosphate?buffered saline control group (P<0.01). Tissue expression of vascular endothelial growth factor C mRNA and plasma levels of vascular endothelial growth factor C were greater in the ADRC group than in the control group (P<0.01 and P<0.05, respectively). ADRCs released vascular endothelial growth factor C, which directly stimulated lymphangiogenesis. Implantation of ADRCs also enhanced recruitment of bone marrow–derived M2 macrophages, which served as lymphatic endothelial progenitor cells. Conclusions Implantation of autologous ADRCs could be a useful treatment option for patients with severe lymphedema via mediation of lymphangiogenesis. (J Am Heart Assoc. 2012;1:e000877 doi: 10.1161/JAHA.112.000877.) PMID:23130156

Shimizu, Yuuki; Shibata, Rei; Shintani, Satoshi; Ishii, Masakazu; Murohara, Toyoaki

2012-01-01

338

The clinical use of regenerative therapy in COPD  

PubMed Central

Regenerative or stem cell therapy is an emerging field of treatment based on stimulation of endogenous resident stem cells or administration of exogenous stem cells to treat diseases or injury and to replace malfunctioning or damaged tissues. Current evidence suggests that in the lung, these cells may participate in tissue homeostasis and regeneration after injury. Animal and human studies have demonstrated that tissue-specific stem cells and bone marrow-derived cells contribute to lung tissue regeneration and protection, and thus administration of exogenous stem/progenitor cells or humoral factors responsible for the activation of endogenous stem/progenitor cells may be a potent next-generation therapy for chronic obstructive pulmonary disease. The use of bone marrow-derived stem cells could allow repairing and regenerate the damaged tissue present in chronic obstructive pulmonary disease by means of their engraftment into the lung. Another approach could be the stimulation of resident stem cells by means of humoral factors or photobiostimulation. PMID:25548520

Lipsi, Roberto; Rogliani, Paola; Calzetta, Luigino; Segreti, Andrea; Cazzola, Mario

2014-01-01

339

Induced Pluripotent Stem Cell Technology in Regenerative Medicine and Biology  

NASA Astrophysics Data System (ADS)

The potential of human embryonic stem cells (ESCs) for regenerative medicine is unquestionable, but practical and ethical considerations have hampered clinical application and research. In an attempt to overcome these issues, the conversion of somatic cells into pluripotent stem cells similar to ESCs, commonly termed nuclear reprogramming, has been a top objective of contemporary biology. More than 40 years ago, King, Briggs, and Gurdon pioneered somatic cell nuclear reprogramming in frogs, and in 1981 Evans successfully isolated mouse ESCs. In 1997 Wilmut and collaborators produced the first cloned mammal using nuclear transfer, and then Thomson obtained human ESCs from in vitro fertilized blastocysts in 1998. Over the last 2 decades we have also seen remarkable findings regarding how ESC behavior is controlled, the importance of which should not be underestimated. This knowledge allowed the laboratory of Shinya Yamanaka to overcome brilliantly conceptual and technical barriers in 2006 and generate induced pluripotent stem cells (iPSCs) from mouse fibroblasts by overexpressing defined combinations of ESC-enriched transcription factors. Here, we discuss some important implications of human iPSCs for biology and medicine and also point to possible future directions.

Pei, Duanqing; Xu, Jianyong; Zhuang, Qiang; Tse, Hung-Fat; Esteban, Miguel A.

340

Regenerative fuel cell study for satellites in GEO orbit  

NASA Technical Reports Server (NTRS)

Summarized are the results of a 12-month study to identify high performance regenerative hydrogen-oxygen fuel cell concepts for geosynchronous satellite application. Emphasis was placed on concepts with the potential for high energy density (W-hr/lb) and passive means for water and heat management to maximize system reliability. Both polymer membrane and alkaline electrolyte fuel cells were considered, with emphasis on the alkaline cell because of its high performance, advanced state of development, and proven ability to operate in a launch and space environment. Three alkaline system concepts were studied. The first, the integrated design, utilized a configuration in which the fuel cell and electrolysis cells are alternately stacked inside a pressure vessel. Product water is transferred by diffusion during electrolysis and waste heat is conducted through the pressure wall, thus using completely passive means for transfer and control. The second alkaline system, the dedicated design, uses a separate fuel cell and electrolysis stack so that each unit can be optimized in size and weight based on its orbital operating period. The third design was a dual function stack configuration, in which each cell can operate in both fuel cell and electrolysis mode, thus eliminating the need for two separate stacks and associated equipment. Results indicate that using near term technology energy densities between 46 and 52 W-hr/lb can be achieved at efficiencies of 55 percent. System densities of 115 W-hr/lb are contemplated.

Levy, Alexander; Vandine, Leslie L.; Stedman, James K.

1987-01-01

341

Inhibition of intracranial glioma growth by endometrial regenerative cells.  

PubMed

Animal studies have demonstrated that selective tropism of mesenchymal stem cells (MSC) for glioma may be used as a means of selective delivery of cytotoxic payloads. Endometrial Regenerative Cells (ERC) are a population of mesenchymal-like cells which possesse pluripotent differentiation capacity and is characterized by unique surface markers and growth factor production. In this study we sought to determine whether unmanipulated ERC would alter the growth of glioma using the aggressive C6/LacZ7 (C6) into Sprague Dawley rat model. ERC administration by intravenous (i.v.) or intratumoral (i.t.) showed significant inhibition of glioma: volume reduction of 49% after i.v. treatment (p < 0.05), and about 46% i.t. treatment (p < 0.05). Tumor reduction was associated with inhibition of angiogenesis and reduced numbers of CD133 positive cells in the incranial tumor. Despite the angiogenic potential of ERC in the hindlimb ischemia model, these data support a paradoxical tumor inhibitory activity of ERC. Further studies are needed to determine the qualitative differences between physiological angiogenesis, which seems to be supported by ERC and tumor angiogenesis which appeared to be inhibited. PMID:19197154

Han, Xiaodi; Meng, Xiaolong; Yin, Zhenglian; Rogers, Andrea; Zhong, Jie; Rillema, Paul; Jackson, James A; Ichim, Thomas E; Minev, Boris; Carrier, Ewa; Patel, Amit N; Murphy, Michael P; Min, Wei-Ping; Riordan, Neil H

2009-02-15

342

Endometrial regenerative cells: A novel stem cell population  

PubMed Central

Angiogenesis is a critical component of the proliferative endometrial phase of the menstrual cycle. Thus, we hypothesized that a stem cell-like population exist and can be isolated from menstrual blood. Mononuclear cells collected from the menstrual blood contained a subpopulation of adherent cells which could be maintained in tissue culture for >68 doublings and retained expression of the markers CD9, CD29, CD41a, CD44, CD59, CD73, CD90 and CD105, without karyotypic abnormalities. Proliferative rate of the cells was significantly higher than control umbilical cord derived mesenchymal stem cells, with doubling occurring every 19.4 hours. These cells, which we termed "Endometrial Regenerative Cells" (ERC) were capable of differentiating into 9 lineages: cardiomyocytic, respiratory epithelial, neurocytic, myocytic, endothelial, pancreatic, hepatic, adipocytic, and osteogenic. Additionally, ERC produced MMP3, MMP10, GM-CSF, angiopoietin-2 and PDGF-BB at 10–100,000 fold higher levels than two control cord blood derived mesenchymal stem cell lines. Given the ease of extraction and pluripotency of this cell population, we propose ERC as a novel alternative to current stem cells sources. PMID:18005405

Meng, Xiaolong; Ichim, Thomas E; Zhong, Jie; Rogers, Andrea; Yin, Zhenglian; Jackson, James; Wang, Hao; Ge, Wei; Bogin, Vladimir; Chan, Kyle W; Thébaud, Bernard; Riordan, Neil H

2007-01-01

343

Prospect of Stem Cell Conditioned Medium in Regenerative Medicine  

PubMed Central

Background. Stem cell-derived conditioned medium has a promising prospect to be produced as pharmaceuticals for regenerative medicine. Objective. To investigate various methods to obtain stem cell-derived conditioned medium (CM) to get an insight into their prospect of application in various diseases. Methods. Systematic review using keywords “stem cell” and “conditioned medium” or “secretome” and “therapy.” Data concerning treated conditions/diseases, type of cell that was cultured, medium and supplements to culture the cells, culture condition, CM processing, growth factors and other secretions that were analyzed, method of application, and outcome were noted, grouped, tabulated, and analyzed. Results. Most of CM using studies showed good results. However, the various CM, even when they were derived from the same kind of cells, were produced by different condition, that is, from different passage, culture medium, and culture condition. The growth factor yields of the various types of cells were available in some studies, and the cell number that was needed to produce CM for one application could be computed. Conclusion. Various stem cell-derived conditioned media were tested on various diseases and mostly showed good results. However, standardized methods of production and validations of their use need to be conducted. PMID:25530971

Pawitan, Jeanne Adiwinata

2014-01-01

344

Satellite cells from dystrophic muscle retain regenerative capacity  

PubMed Central

Duchenne muscular dystrophy is an inherited disorder that is characterized by progressive skeletal muscle weakness and wasting, with a failure of muscle maintenance/repair mediated by satellite cells (muscle stem cells). The function of skeletal muscle stem cells resident in dystrophic muscle may be perturbed by being in an increasing pathogenic environment, coupled with constant demands for repairing muscle. To investigate the contribution of satellite cell exhaustion to this process, we tested the functionality of satellite cells isolated from the mdx mouse model of Duchenne muscular dystrophy. We found that satellite cells derived from young mdx mice contributed efficiently to muscle regeneration within our in vivo mouse model. To then test the effects of long-term residence in a dystrophic environment, satellite cells were isolated from aged mdx muscle. Surprisingly, they were as functional as those derived from young or aged wild type donors. Removing satellite cells from a dystrophic milieu reveals that their regenerative capacity remains both intact and similar to satellite cells derived from healthy muscle, indicating that the host environment is critical for controlling satellite cell function. PMID:25460248

Boldrin, Luisa; Zammit, Peter S.; Morgan, Jennifer E.

2015-01-01

345

Cord blood in regenerative medicine: do we need immune suppression?  

PubMed Central

Cord blood is currently used as an alternative to bone marrow as a source of stem cells for hematopoietic reconstitution after ablation. It is also under intense preclinical investigation for a variety of indications ranging from stroke, to limb ischemia, to myocardial regeneration. A major drawback in the current use of cord blood is that substantial morbidity and mortality are associated with pre-transplant ablation of the recipient hematopoietic system. Here we raise the possibility that due to unique immunological properties of both the stem cell and non-stem cell components of cord blood, it may be possible to utilize allogeneic cells for regenerative applications without needing to fully compromise the recipient immune system. Issues raised will include: graft versus host potential, the immunogeneicity of the cord blood graft, and the parallels between cord blood transplantation and fetal to maternal trafficking. The previous use of unmatched cord blood in absence of any immune ablation, as well as potential steps for widespread clinical implementation of allogeneic cord blood grafts will also be discussed. PMID:17261200

Riordan, Neil H; Chan, Kyle; Marleau, Annette M; Ichim, Thomas E

2007-01-01

346

Potency of Fish Collagen as a Scaffold for Regenerative Medicine  

PubMed Central

Cells, growth factors, and scaffold are the crucial factors for tissue engineering. Recently, scaffolds consisting of natural polymers, such as collagen and gelatin, bioabsorbable synthetic polymers, such as polylactic acid and polyglycolic acid, and inorganic materials, such as hydroxyapatite, as well as composite materials have been rapidly developed. In particular, collagen is the most promising material for tissue engineering due to its biocompatibility and biodegradability. Collagen contains specific cell adhesion domains, including the arginine-glycine-aspartic acid (RGD) motif. After the integrin receptor on the cell surface binds to the RGD motif on the collagen molecule, cell adhesion is actively induced. This interaction contributes to the promotion of cell growth and differentiation and the regulation of various cell functions. However, it is difficult to use a pure collagen scaffold as a tissue engineering material due to its low mechanical strength. In order to make up for this disadvantage, collagen scaffolds are often modified using a cross-linker, such as gamma irradiation and carbodiimide. Taking into account the possibility of zoonosis, a variety of recent reports have been documented using fish collagen scaffolds. We herein review the potency of fish collagen scaffolds as well as associated problems to be addressed for use in regenerative medicine. PMID:24982861

Yamamoto, Kohei; Yanagiguchi, Kajiro

2014-01-01

347

Tissue engineering and regenerative medicine: a year in review.  

PubMed

It is an exciting time to be involved in tissue engineering and regenerative medicine (TERM) research. Despite its relative youth, the field is expanding fast and breaking new ground in both the laboratory and clinically. In this "Year in Review," we highlight some of the high-impact advances in the field. Building upon last year's article, we have identified the recent "hot topics" and the key publications pertaining to these themes as well as ideas that have high potential to direct the field. Based on a modified methodology grounded on last year's approach, we have identified and summarized some of the most impactful publications in five main themes: (1) pluripotent stem cells: efforts and hurdles to translation, (2) tissue engineering: complex scaffolds and advanced materials, (3) directing the cell phenotype: growth factor and biomolecule presentation, (4) characterization: imaging and beyond, and (5) translation: preclinical to clinical. We have complemented our review of the research directions highlighted within these trend-setting studies with a discussion of additional articles along the same themes that have recently been published and have yet to surface in citation analyses. We conclude with a discussion of some really interesting studies that provide a glimpse of the high potential for innovation of TERM research. PMID:24410501

Harrison, Rachael H; St-Pierre, Jean-Philippe; Stevens, Molly M

2014-02-01

348

Mesenchymal stem cells: environmentally responsive therapeutics for regenerative medicine  

PubMed Central

Mesenchymal stem cells (MSCs) are partially defined by their ability to differentiate into tissues including bone, cartilage and adipose in vitro, but it is their trophic, paracrine and immunomodulatory functions that may have the greatest therapeutic impact in vivo. Unlike pharmaceutical treatments that deliver a single agent at a specific dose, MSCs are site regulated and secrete bioactive factors and signals at variable concentrations in response to local microenvironmental cues. Significant progress has been made in understanding the biochemical and metabolic mechanisms and feedback associated with MSC response. The anti-inflammatory and immunomodulatory capacity of MSC may be paramount in the restoration of localized or systemic conditions for normal healing and tissue regeneration. Allogeneic MSC treatments, categorized as a drug by regulatory agencies, have been widely pursued, but new studies demonstrate the efficacy of autologous MSC therapies, even for individuals affected by a disease state. Safety and regulatory concerns surrounding allogeneic cell preparations make autologous and minimally manipulated cell therapies an attractive option for many regenerative, anti-inflammatory and autoimmune applications. PMID:24232253

Murphy, Matthew B; Moncivais, Kathryn; Caplan, Arnold I

2013-01-01

349

Photoselective Vaporization for the Treatment of Benign Prostatic Hyperplasia  

PubMed Central

Background As an alternative to transurethral resection of the prostate (TURP), photoselective vaporization of the prostate (PVP) provides a bloodless, relatively painless relief of lower urinary tract symptoms for men with benign prostatic hyperplasia. Following a review of the evidence in 2006, the Ontario Health Technology Advisory Committee recommended that a study be conducted to evaluate PVP in Ontario. Objectives To compare the clinical effectiveness, safety, cost-effectiveness, and budget impact of PVP compared to conventional TURP for the treatment of benign prostatic hyperplasia in Ontario. Methods A prospective, nonrandomized trial was conducted in 3 Ontario centres. Consenting subjects were assessed at baseline and 1, 3, and 6 months following surgery. Outcome measures included International Prostate Symptom Score (IPSS), peak urinary flow rate (Qmax), post-void residual (PVR) volume, prostate-specific antigen (PSA), health-related quality of life (HRQOL) using the EuroQol 5 Domain questionnaire, and the Sexual Health Inventory for Men (SHIM) score. Adverse events, resource utilization, and productivity losses were also assessed. Cost-effectiveness and budget impact analyses were completed using data from the study. Results Between February 2008 and August 2010, 164 subjects were enrolled in the study (n = 140 for PVP and n = 24 for TURP). Treatment outcomes were similar between the 2 groups at 6 months, with the IPSS decreasing similarly over time (P = 0.718). For other treatment outcomes (Qmax, PSA, HRQOL, SHIM) both treatments provided similar benefit over time; only changes in PVR volume favoured PVP (P = 0.018). The majority of PVP patients were managed on an outpatient basis, with only 7.1% requiring admission (all TURP subjects were inpatients). At 6 months, PVP was less costly than TURP ($3,891 versus $4,863; P = 0.001), with similar quality-adjusted life-years (0.448 versus 0.441; P = 0.658). PVP remained the most cost-effective treatment across all decision-making thresholds, with the technology costing less and providing similar clinical outcomes. Extrapolating the results to a provincial level indicated (based on an estimated case volume of 12,335 TURPs) that there is an opportunity to reallocate just over $14 million (Cdn), primarily related to the reduced need for hospital admission. Limitations This study was nonrandomized, and the results should be interpreted with some caution, despite generally similar baseline characteristics between the 2 groups. Recruiting individuals to the TURP arm was a challenge, resulting in a size imbalance between treatment arms. Conclusions Based on this analysis, PVP appears to be a cost-effective alternative to TURP, providing similar clinical benefit at a lower cost to the health system. Plain Language Summary For men with lower urinary tract symptoms due to an enlarged prostate, a laser treatment called photoselective vaporization of the prostate (or PVP) is just as effective as surgery. PVP does not require an overnight stay in the hospital for most men, and it costs almost $1,000 less. This report describes the results of a study that collected information about treatment outcomes, quality of life, and health care use related to PVP and surgery in Ontario. PMID:24019857

Bowen, James M.; Whelan, J. Paul; Hopkins, Robert B.; Burke, Natasha; Woods, Edward A.; McIsaac, Gary P.; O’Reilly, Daria J.; Xie, Feng; Sehatzadeh, Shayan; Levin, Leslie; Mathew, Suja P.; Patterson, Lisa L.; Goeree, Ron; Tarride, Jean-Eric

2013-01-01

350

Testicular Adrenal Rest Tumors in Patients with Congenital Adrenal Hyperplasia  

PubMed Central

Objective: Early diagnosis and treatment of testicular adrenal rest tumors (TART) is important for gonadal functions and fertility protection in boys with congenital adrenal hyperplasia (CAH). In this descriptive study, we investigated the prevalence of TART in boys with 21-hydroxylase deficient (21OHD) CAH followed in our pediatric endocrine clinic. Methods: The study group consisted of 14 male patients with a mean age of 9.6±5.1 (range: 0.8-18.3) years. Six (42.9%) of the 14 patients were diagnosed as having salt-wasting type (SW) and eight (57.1%) patients - as having the simple virilizing (SV) form of 21OHD. Mean age at diagnosis was 2.9±2.7 (range: 0.03-6.3) years. Two different radiologists performed scrotal ultrasonography. Chronological age, bone age, and anthropometric measurements were evaluated. Serum adrenocorticotropic hormone (ACTH), 17-alpha-hydroxyprogesterone (17OHP) and androstenedione levels were also evaluated in all patients during the follow-up period. Results: Scrotal ultrasonography revealed bilateral TART in two patients (14.3%) and testicular microlithiasis (TM) in four patients (28.6%). One patient had both TART and TM bilaterally. During the follow-up period, the mean serum adrenocorticotropic hormone, 17OHP and androstenedione levels in the total group of patients were 130.0±179.1 pg/mL (21.7-726.5), 5.8±3.3 ng/mL (0.8-11.4) and 4.3±4.1 (0.2-11.0) ng/mL, respectively. Conclusions: Microlithiasis or TART may be frequently encountered during the follow-up of patients with CAH. In order to prevent late complications including infertility, we suggest that ultrasonographic evaluations be performed yearly in all male CAH patients. Conflict of interest:None declared. PMID:22672867

?entürk Mutlu, Fatma; Eren, Erdal; Pa?a, Aliye Özlem; Sa?lam, Halil; Tar?m, Ömer

2012-01-01

351

Various treatment options for benign prostatic hyperplasia: A current update  

PubMed Central

In benign prostatic hyperplasia (BPH) there will be a sudden impact on overall quality of life of patient. This disease occurs normally at the age of 40 or above and also is associated with sexual dysfunction. Thus, there is a need of update on current medications of this disease. The presented review provides information on medications available for BPH. Phytotherapies with some improvements in BPH are also included. Relevant articles were identified through a search of the English-language literature indexed on MEDLINE, PUBMED, Sciencedirect and the proceedings of scientific meetings. The search terms were BPH, medications for BPH, drugs for BPH, combination therapies for BPH, Phytotherapies for BPH, Ayurveda and BPH, BPH treatments in Ayurveda. Medications including watchful waitings, Alpha one adrenoreceptor blockers, 5-alpha reductase inhibitors, combination therapies including tamsulosin-dutasteride, doxazosin-finasteride, terazosin-finasteride, tolterodine-tamsulosin and rofecoxib-finasteride were found. Herbal remedies such as Cernilton, Saxifraga stolonifera, Zi-Shen Pill (ZSP), Orbignya speciosa, Phellodendron amurense, Ganoderma lucidum, Serenoa Repens, pumpkin extract and Lepidium meyenii (Red Maca) have some improvements on BPH are included. Other than these discussions on Ayurvedic medications, TURP and minimally invasive therapies (MITs) are also included. Recent advancements in terms of newly synthesized molecules are also discussed. Specific alpha one adrenoreceptor blockers such as tamsulosin and alfuzosin will remain preferred choice of urologists for symptom relief. Medications with combination therapies are still needs more investigation to establish as preference in initial stage for fast symptom relief reduced prostate growth and obviously reduce need for BPH-related surgery. Due to lack of proper evidence Phytotherapies are not gaining much advantage. MITs and TURP are expensive and are rarely supported by healthcare systems. PMID:22923974

Shrivastava, Alankar; Gupta, Vipin B.

2012-01-01

352

The overlooked cause of benign prostatic hyperplasia: prostatic urethral angulation.  

PubMed

Benign prostatic hyperplasia (BPH) is one of the most common problems faced by aging men and can be associated with bothersome lower urinary tract symptoms that affect quality of life by interfering with normal daily activities and sleep patterns. Despite the clinical importance of BPH, its pathogenesis is still poorly understood. Previously, our understanding of BPH was centered on bladder outlet obstruction being secondary to benign prostatic enlargement. However, prostate size itself is not correlated with the urine flow rate and symptomatology. The prostatic urethra is a bend tube and the increased prostatic urethral angulation shows a higher bladder neck on cystoscopic examination. Although some urologists suspected that the higher bladder neck might be a causal factor for BPH, the clinical significance of prostatic urethral angulation was previously underestimated. In this study, we propose a new hypothesis that prostatic urethral angulation is a causal factor for BPH. By applying the concept of fluid dynamics to the process of urination in the prostatic urethra, we show that the energy loss in this bending tube (the prostatic urethra) can occur during micturition and it increases proportionally to prostatic urethral angulation; this energy loss results in a decrease of the urine velocity and accordingly, the urine flow rate is inversely associated with prostatic urethral angulation. We also propose that BPH involves prostatic urethral angulation as well as the classical BPH triad of prostatic enlargement, bladder outlet obstruction, and symptomatology. Our hypothesis suggests that prostatic urethral angulation is an overlooked cause of bladder outlet obstruction and is a causal factor of BPH, and provides novel insight into the pathogenesis of BPH. Ultimately, the relationship between prostatic urethral angulation and urine flow rate, and other clinical factors including urodynamic parameters, the symptomatology, the response to treatment, and disease progression, need to be investigated in a clinical setting. PMID:17761390

Cho, Kang Su; Kim, Joohan; Choi, Young Deuk; Kim, Jang Hwan; Hong, Sung Joon

2008-01-01

353

Long segmental hyperplasia of interstitial cells of Cajal with giant diverticulum formation  

PubMed Central

Sporadic gastrointestinal stromal tumors (GISTs) usually form a well-circumscribed mass. In contrast, diffuse interstitial cell of Cajal (ICC) hyperplasia along the Auerbach plexus without a discrete mass may occur in patients with germline mutations in the NF1, c-KIT or PDGFRA genes. However, sporadic, diffuse ICC hyperplasia without c-KIT or PDGFRA mutations has not been reported. We describe herein one such case, forming a giant diverticulum. A 63-year-old woman with no features of Neurofibromatosis 1 (NF1) presented with increasing abdominal pain for more than 30 years. A large, diverticulum-like mass in the ileum was resected. Microscopically, a diffuse proliferation of bland spindle cells was seen extending for 12 cm, replacing the muscularis propria and lined by intact mucosa. The spindle cells were CD117+/CD34+/DOG1+/SMA+/Desmin-/S100-. Mutation analyses did not reveal any mutations in c-KIT or PDGFRA. The lesion had two silent mutations in the NF1 gene. It is rare of the diffuse form of sporadic ICC hyperplasia showing diffuse longitudinal microscopic growth completely replacing the muscularis propria, mimicking diffuse ICC hyperplasia in hereditary GIST syndromes, but without solid components and no c-KIT or PDGFRA gene mutations. This peculiar form of sporadic ICC hyperplasia may be related to intestinal dysmotility in this ileal segment and giant diverticulum formation. PMID:24294389

Xue, Liyan; Qiu, Tian; Song, Ying; Shan, Ling; Liu, Xiuyun; Guo, Lei; Ying, Jianming; Zou, Shuangmei; Shi, Susheng; Polydorides, Alexandros D; Zhao, Xinming; Lu, Ning; Lin, Dongmei

2013-01-01

354

A Simplified Murine Intimal Hyperplasia Model Founded on a Focal Carotid Stenosis  

PubMed Central

Murine models offer a powerful tool for unraveling the mechanisms of intimal hyperplasia and vascular remodeling, although their technical complexity increases experimental variability and limits widespread application. We describe a simple and clinically relevant mouse model of arterial intimal hyperplasia and remodeling. Focal left carotid artery (LCA) stenosis was created by placing 9-0 nylon suture around the artery using an external 35-gauge mandrel needle (middle or distal location), which was then removed. The effect of adjunctive diet-induced obesity was defined. Flowmetry, wall strain analyses, biomicroscopy, and histology were completed. LCA blood flow sharply decreased by ?85%, followed by a responsive right carotid artery increase of ?71%. Circumferential strain decreased by ?2.1% proximal to the stenosis in both dietary groups. At 28 days, morphologic adaptations included proximal LCA intimal hyperplasia, which was exacerbated by diet-induced obesity. The proximal and distal LCA underwent outward and negative inward remodeling, respectively, in the mid-focal stenosis (remodeling indexes, 1.10 and 0.53). A simple, defined common carotid focal stenosis yields reproducible murine intimal hyperplasia and substantial differentials in arterial wall adaptations. This model offers a tool for investigating mechanisms of hemodynamically driven intimal hyperplasia and arterial wall remodeling. PMID:23159527

Tao, Ming; Mauro, Christine R.; Yu, Peng; Favreau, John T.; Nguyen, Binh; Gaudette, Glenn R.; Ozaki, C. Keith

2014-01-01

355

Adenomatoid hyperplasia of the minor salivary glands on the buccal mucosa: A rare case report  

PubMed Central

INTRODUCTION Adenomatoid hyperplasia of the minor salivary glands is a hyperplastic oral lesion which may be seen on minor salivary gland bearing areas on all oral mucosa, especially on soft and hard palate. This study reports a rare case of buccal adenomatoid hyperplasia of the minor salivary glands and discusses the clinical significance. PRESENTATION OF CASE 48 year old male patient presented with a complaint of a swelling on his left cheek. Clinical examination revealed a bluish mass on the buccal mucosa. A provisional diagnosis of salivary gland neoplasm was made and the lesion was excised under local anesthesia. The histological diagnosis was adenomatoid hyperplasia of the minor salivary glands. DISCUSSION Buccal localization of the adenomatoid hyperplasia of the minor salivary glands is quite uncommon in the literature. There are two cases in the English literature for our knowledge. In the clinical examination, the nodular and protuberated appearance of the lesion resembles buccal minor salivary gland tumors and vascular lesions. Histological analysis is fundamental to achieve correct diagnosis. CONCLUSION The differential diagnosis of buccal nodular, exophytic and colored mucosal lesions should include adenomatoid hyperplasia of the minor salivary glands. PMID:24727208

Dereci, Ömür; Çimen, Emre

2014-01-01

356

Intimal hyperplasia in loop-injured carotid arteries is attenuated in transglutaminase 2-null mice.  

PubMed

Arterial restenosis frequently develops after open or endovascular surgery due to intimal hyperplasia. Since tissue transglutaminase (TG2) is known to involve in fibrosis, wound healing, and extracellular matrix remodeling, we examined the role of TG2 in the process of intimal hyperplasia using TG2-null mice. The neointimal formation was compared between TG2-null and wild-type (C57BL/6) mice by two different injury models; carotid ligation and carotid loop injury. In ligation model, there was no difference in intimal thickness between two groups. In loop injury model, intimal hyperplasia developed in both groups and the intimal/medial area ratio was significantly reduced in TG2-null mice (P = 0.007). TG2 was intensely stained in neointimal cells in 2 weeks. In situ activity of TG2 in the injured arteries steadily increased until 4 weeks compared to uninjured arteries. Taken together, intimal hyperplasia was significantly reduced in TG2-null mice, indicating that TG2 has an important role in the development of intimal hyperplasia. This suggests that TG2 may be a novel target to prevent the arterial restenosis after vascular surgery. PMID:24616585

Min, Seung-Kee; Min, Sang-Il; Jeong, Eui Man; Cho, Sung-Yup; Ha, Jongwon; Kim, Sang Joon; Kim, In-Gyu

2014-03-01

357

The promise of perfect adult tissue repair and regeneration in mammals: Learning from regenerative amphibians and fish.  

PubMed

Regenerative medicine promises to greatly impact on human health by improving repair outcomes in a range of tissues and injury contexts. Successful therapies will rely on identifying both intrinsic and extrinsic biological circuits that control wound healing, proliferation, cell survival, and developmental cell fate. Animals such as the zebrafish and the salamander display powerful examples of near-perfect regeneration and scar-free healing in a range of injury contexts not attained in mammals. By studying regeneration in a range of highly regenerative species that maintain regenerative potential throughout life, many instructive and permissive factors have been identified that could assist in the development of regenerative therapies. This review highlights some of the recent observations in immune regulation, epigenetic regulation, stem cell mobilization, and regenerative signatures that have improved our understanding of the regenerative process. Potential opportunities in harnessing this knowledge for future translation into the clinic are discussed. PMID:25043537

Godwin, James

2014-09-01

358

77H.S. Bernstein (ed.), Tissue Engineering in Regenerative Medicine, Stem Cell Biology and Regenerative Medicine, DOI 10.1007/978-1-61779-322-6_5,  

E-print Network

77H.S. Bernstein (ed.), Tissue Engineering in Regenerative Medicine, Stem Cell Biology Stem cell differentiation is regulated by a diverse array of extracellular cues. Recent evidence as physical interactions between neighboring cells play important roles in stem cell self

Parker, Kevin Kit

359

Determination of the effectiveness and feasibility of regenerative braking systems on electric and other automobiles. Volume 1. Summary  

Microsoft Academic Search

A Lawrence Livermore Laboratory study to determine the effectiveness and feasibility of regenerative braking systems on electric and other automobiles is reported. Regenerative braking concepts applicable to automobiles using electric, hybrid, or heat-engine power systems were evaluated for performance improvement, energy saving, and cost-effectiveness. Two major conclusions pertain to privately owned automobiles driven 16,100 km\\/yr in an urban environment: regenerative

D. D. Davis; R. A. Renner; F. C. Younger; R. C. Epps; S. S. Lerner

1977-01-01

360

Design and experiment study of a semi-active energy-regenerative suspension system  

NASA Astrophysics Data System (ADS)

A new kind of semi-active energy-regenerative suspension system is proposed to recover suspension vibration energy, as well as to reduce the suspension cost and demands for the motor-rated capacity. The system consists of an energy-regenerative damper and a DC-DC converter-based energy-regenerative circuit. The energy-regenerative damper is composed of an electromagnetic linear motor and an adjustable shock absorber with three regulating levels. The linear motor just works as the generator to harvest the suspension vibration energy. The circuit can be used to improve the system’s energy-regenerative performance and to continuously regulate the motor’s electromagnetic damping force. Therefore, although the motor works as a generator and damps the isolation without an external power source, the motor damping force is controllable. The damping characteristics of the system are studied based on a two degrees of freedom vehicle vibration model. By further analyzing the circuit operation characteristics under different working modes, the double-loop controller is designed to track the desired damping force. The external-loop is a fuzzy controller that offers the desired equivalent damping. The inner-loop controller, on one hand, is used to generate the pulse number and the frequency to control the angle and the rotational speed of the step motor; on the other hand, the inner-loop is used to offer the duty cycle of the energy-regenerative circuit. Simulations and experiments are conducted to validate such a new suspension system. The results show that the semi-active energy-regenerative suspension can improve vehicle ride comfort with the controllable damping characteristics of the linear motor. Meanwhile, it also ensures energy regeneration.

Shi, Dehua; Chen, Long; Wang, Ruochen; Jiang, Haobin; Shen, Yujie

2015-01-01

361

Atypical adenomatous hyperplasia of the lung: a clinicopathological study of 118 cases including cases with multiple atypical adenomatous hyperplasia  

PubMed Central

BACKGROUND—Atypical adenomatous hyperplasia (AAH) of the lung is a putative precursor lesion of adenocarcinoma, according to many immunohistochemical and genetical studies, but few clinicopathological studies on a large number of cases have been reported. The aim of this study was to clarify the clinicopathological characteristics of lung cancer patients with AAH lesions.?METHODS—A retrospective study was carried out on 508 consecutive primary lung cancer patients operated on at National Cancer Center Hospital East. The relationship between the number and location of AAH lesions and the clinicopathological features of the lung cancer patients was analysed statistically.?RESULTS—A total of 311 AAH lesions were found in 118 (23.2%) of the 508 cases. AAH lesions were detected in 121 of 572 lobes examined, usually in both upper lobes, and occurred most frequently in patients with adenocarcinoma (OR 2.97; 95% CI 1.82 to 4.85). AAH lesions were more frequently detected in patients with multiple primary carcinomas than in those with a single carcinoma (OR 3.06; 95% CI 1.56 to 6.00). The presence of AAH lesions was not significantly correlated with sex, age, smoking status, familial history of malignancy, or preceding malignancy. Patients with multiple AAH lesions were found to have a significantly higher frequency of preceding malignancies.?CONCLUSIONS—The present study highlights the clinicopathological characteristics of AAH lesions, showing them to be significantly associated with both adenocarcinoma and multiple primary carcinoma of the lung and suggesting common factors in the histogenesis of multiple AAH lesions and preceding malignancy.?? PMID:11254822

Nakahara, R; Yokose, T; Nagai, K; Nishiwaki, Y; Ochiai, A

2001-01-01

362

Lymphoid hyperplasia detected as a single mass in the gallbladder: report of a case.  

PubMed

We herein report a case of lymphoid hyperplasia of the gallbladder that showed unique images on computed tomography and ultrasonography. A 42-year-old female was referred to our hospital for evaluation and treatment of a gallbladder tumor. Ultrasonography and computed tomography showed a mass in the wall of the gallbladder neck, without typical findings of benign or malignant tumors. The serum levels of tumor markers, such as carcinoembryonic antigen, carbohydrate antigen 19-9, alpha-fetoprotein, and cytokeratin 19 fragment, were all within normal limits. Laparoscopic cholecystectomy was therefore performed. There were no stones in the gallbladder. Macroscopically, the submural tumor had a clear border without a capsule and a cystic portion. Its cut surface was grayish white. Microscopically, many lymph follicles with germinal centers were recognized in the subserosal layer. The lymphocytes were morphologically normal. We diagnosed lymphoid hyperplasia with chronic cholecystitis. Lymphoid hyperplasia of the gallbladder is extremely rare. PMID:22699402

Yamamoto, Satoshi; Tsukamoto, Tadashi; Kanazawa, Akishige; Shimizu, Sadatoshi; Mikamori, Manabu; Fujiwara, Yushi; Nagahara, Hisashi; Xiang, Zhang; Sakurai, Katsunobu; Inoue, Ken

2012-12-01

363

Mammary diffuse fibroadenomatoid hyperplasia in water buffalo (Bubalus bubalis): three cases.  

PubMed

The current report describes 3 rare cases of mammary diffuse fibroadenomatoid hyperplasia in water buffalo (Bubalus bubalis). All of the animals were between 10 and 12 months of age. Grossly, the lesions consisted of severe diffuse swelling with homogeneous large masses in the udder. Surgical removal of the masses was curative. Microscopically, there was severe hyperplasia of the mammary epithelium and numerous well-differentiated and mildly pleomorphic acini and their associated ducts. Moderate proliferation of the fibrous connective tissue and the myoepithelial cells near the proliferating acini was also evident. The hyperplastic epithelial cells exhibited positive immunostaining for cytokeratin, estrogen receptors, and progesterone receptors. In addition, the myoepithelial cells displayed moderate positivity for alpha smooth muscle actin. Based on the clinical, morphologic, and immunohistochemical findings, a diagnosis of mammary diffuse fibroadenomatoid hyperplasia with probable hormonal influence was made. PMID:24621849

de Sant'Ana, Fabiano J F; Carvalho, Fausto C; de O Gamba, Conrado; Cassali, Geovanni D; Riet-Correa, Franklin; Schild, Ana L

2014-03-12

364

Mouth opening limitation caused by coronoid hyperplasia: a report of four cases  

PubMed Central

Coronoid process hyperplasia is a rare condition that causes mouth opening limitation, otherwise known as trismus. The elongated coronoid processes impinge on the medial surfaces of the zygomatic arches when opening the mouth, which limits movement of the mandible and leads to trismus. Patients with trismus due to coronoid process hyperplasia do not have any definite symptoms such as temporomandibular joint pain or sounds upon clinical examination, and no significant abnormal signs are observed on panoramic radiographs or magnetic resonance images of the temporomandibular joint. Thus, the diagnosis of trismus is usually very difficult. However, computed tomography can help with the diagnosis, and the condition can be treated by surgery and postoperative physical therapy. This paper describes four cases of patients who visited our clinic for trismus and were subsequently diagnosed with coronoid process hyperplasia. Three were successfully treated with a coronoidectomy and postoperative physical therapy.

Kim, Sung-Min; Lee, Jin-Hyeok; Kim, Hak-Jin

2014-01-01

365

Liability versus innovation: the legal case for regenerative medicine.  

PubMed

Medical innovation occupies a position somewhere between standard practice and clinical research, but innovation is primarily intended to benefit an individual patient where standard treatment fails. Medical innovations in the area of regenerative medicine have the potential to completely transform medical practice, but rely upon some major revision to the nature of treatments beyond drug-based therapies. There is considerable investment in scientific and clinical research, but further attention could be paid to legal barriers to medical innovation imposed by the threat of medical malpractice. We survey in this article the legal framework for making determinations of medical malpractice in general, and highlight the issues specific to innovative treatments. In essence, liability could be imposed for failing to adequately inform the patient about the innovative nature of the suggested therapy or based on the fact that the risks outweighed the benefits. As for the latter, we examine whether liability is likely to be based merely on deviating from existing practice or on an examination on the merits of the treatments' risks and benefits. The facts that some risks are unforeseeable and some benefits are external to the patient complicate negligence determinations. The first fact relates to the problem of judging adverse events in hindsight; the second, to the obligation to make decisions based on the patient's best interest and avoid conflict of interests. In addition, we evaluate the relationship between the obligations to secure the patient's informed consent and to avoid clinical negligence. We identify the need for further research to examine the significance of the putative anti-innovation bias that current liability regimen has, and to examine whether a move to strict liability might avoid such bias, while being fair to patients who contribute for the advancement of medical knowledge by participating in innovative therapies. PMID:24943515

Keren-Paz, Tsachi; El Haj, Alicia J

2014-10-01

366

A Whole-Organ Regenerative Medicine Approach for Liver Replacement  

PubMed Central

Background & Aims The therapy of choice for end-stage liver disease is whole-organ liver transplantation, but this option is limited by a shortage of donor organs. Cell-based therapies and hepatic tissue engineering have been considered as alternatives to liver transplantation, but neither has proven effective to date. A regenerative medicine approach for liver replacement has recently been described that includes the use of a three-dimensional organ scaffold prepared by decellularization of xenogeneic liver. The present study investigates a new, minimally disruptive method for whole-organ liver decellularization and three different cell reseeding strategies to engineer functional liver tissue. Methods A combination of enzymatic, detergent, and mechanical methods are used to remove all cells from isolated rat livers. Whole-organ perfusion is used in a customized organ chamber and the decellularized livers are examined by morphologic, biochemical, and immunolabeling techniques for preservation of the native matrix architecture and composition. Three different methods for hepatocyte seeding of the resultant three-dimensional liver scaffolds are evaluated to maximize cell survival and function: (1) direct parenchymal injection, (2) multistep infusion, or (3) continuous perfusion. Results The decellularization process preserves the three-dimensional macrostructure, the ultrastructure, the composition of the extracellular matrix components, the native microvascular network of the liver, and the bile drainage system, and up to 50% of growth factor content. The three-dimensional liver matrix reseeded with the multistep infusion of hepatocytes generated ?90% of cell engraftment and supported liver-specific functional capacities of the engrafted cells, including albumin production, urea metabolism, and cytochrome P450 induction. Conclusions Whole-organ liver decellularization is possible with maintenance of structure and composition suitable to support functional hepatocytes. PMID:21375407

Zhang, Li; Medberry, Chris; Fukumitsu, Ken; Faulk, Denver; Jiang, Hongbin; Reing, Janet; Gramignoli, Roberto; Komori, Junji; Ross, Mark; Nagaya, Masaki; Lagasse, Eric; Stolz, Donna; Strom, Stephen C.; Fox, Ira J.

2011-01-01

367

The regenerative potential of parietal epithelial cells in adult mice.  

PubMed

Previously, we showed that some podocytes in juvenile mice are recruited from cells lining Bowman's capsule, suggesting that parietal epithelial cells (PECs) are a progenitor cell population for podocytes. To investigate whether PECs also replenish podocytes in adult mice, PECs were genetically labeled in an irreversible fashion in 5-week-old mice. No significant increase in labeled podocytes was observed, even after 18 months. To accelerate a potential regenerative mechanism, progressive glomerular hypertrophy was induced by progressive partial nephrectomies. Again, no significant podocyte replenishment was observed. Rather, labeled PECs exclusively invaded segments of the tuft affected by glomerulosclerosis, consistent with our previous findings. We next reassessed PEC recruitment in juvenile mice using a different reporter mouse and confirmed significant recruitment of labeled PECs onto the glomerular tuft. Moreover, some labeled cells on Bowman's capsule expressed podocyte markers, and cells on Bowman's capsule were also directly labeled in juvenile podocyte-specific Pod-rtTA transgenic mice. In 6-week-old mice, however, cells on Bowman's capsule no longer expressed podocyte-specific markers. Similarly, in human kidneys, some cells on Bowman's capsule expressed the podocyte marker synaptopodin from 2 weeks to 2 years of age but not at 7 years of age. In summary, podocyte regeneration from PECs could not be detected in aging mice or models of glomerular hypertrophy. We propose that a small fraction of committed podocytes reside on Bowman's capsule close to the vascular stalk and are recruited onto the glomerular tuft during infancy to adolescence in mice and humans. PMID:24408873

Berger, Katja; Schulte, Kevin; Boor, Peter; Kuppe, Christoph; van Kuppevelt, Toin H; Floege, Jürgen; Smeets, Bart; Moeller, Marcus J

2014-04-01

368

Substrates coated with silver nanoparticles as a neuronal regenerative material  

PubMed Central

Much effort has been devoted to the design of effective biomaterials for nerve regeneration. Here, we report the novel use of silver nanoparticles (AgNPs) as regenerative agents to promote neuronal growth. We grew neuroblastoma cells on surfaces coated with AgNPs and studied the effect on the development of the neurites during the initiation and the elongation growth phases. We find that the AgNPs function as favorable anchoring sites, and the growth on the AgNP-coated substrates leads to a significantly enhanced neurite outgrowth. Cells grown on substrates coated with AgNPs have initiated three times more neurites than cells grown on uncoated substrates, and two times more than cells grown on substrates sputtered with a plain homogenous layer of silver. The growth of neurites on AgNPs in the elongation phase was enhanced as well. A comparison with substrates coated with gold nanoparticles (AuNPs) and zinc oxide nanoparticles (ZnONPs) demonstrated a clear silver material-driven promoting effect, in addition to the nanotopography. The growth on substrates coated with AgNPs has led to a significantly higher number of initiating neurites when compared to substrates coated with AuNPs or ZnONPs. All nanoparticle-coated substrates affected and promoted the elongation of neurites, with a significant positive maximal effect for the AgNPs. Our results, combined with the well-known antibacterial effect of AgNPs, suggest the use of AgNPs as an attractive nanomaterial – with dual activity – for neuronal repair studies. PMID:24872701

Alon, Noa; Miroshnikov, Yana; Perkas, Nina; Nissan, Ifat; Gedanken, Aharon; Shefi, Orit

2014-01-01

369

Regenerative Therapies for Equine Degenerative Joint Disease: A Preliminary Study  

PubMed Central

Degenerative joint disease (DJD) is a major cause of reduced athletic function and retirement in equine performers. For this reason, regenerative therapies for DJD have gained increasing interest. Platelet-rich plasma (PRP) and mesenchymal stem cells (MSCs) were isolated from a 6-year-old donor horse. MSCs were either used in their native state or after chondrogenic induction. In an initial study, 20 horses with naturally occurring DJD in the fetlock joint were divided in 4 groups and injected with the following: 1) PRP; 2) MSCs; 3) MSCs and PRP; or 4) chondrogenic induced MSCs and PRP. The horses were then evaluated by means of a clinical scoring system after 6 weeks (T1), 12 weeks (T2), 6 months (T3) and 12 months (T4) post injection. In a second study, 30 horses with the same medical background were randomly assigned to one of the two combination therapies and evaluated at T1. The protein expression profile of native MSCs was found to be negative for major histocompatibility (MHC) II and p63, low in MHC I and positive for Ki67, collagen type II (Col II) and Vimentin. Chondrogenic induction resulted in increased mRNA expression of aggrecan, Col II and cartilage oligomeric matrix protein (COMP) as well as in increased protein expression of p63 and glycosaminoglycan, but in decreased protein expression of Ki67. The combined use of PRP and MSCs significantly improved the functionality and sustainability of damaged joints from 6 weeks until 12 months after treatment, compared to PRP treatment alone. The highest short-term clinical evolution scores were obtained with chondrogenic induced MSCs and PRP. This study reports successful in vitro chondrogenic induction of equine MSCs. In vivo application of (induced) MSCs together with PRP in horses suffering from DJD in the fetlock joint resulted in a significant clinical improvement until 12 months after treatment. PMID:24465787

Broeckx, Sarah; Zimmerman, Marieke; Crocetti, Sara; Suls, Marc; Mariën, Tom; Ferguson, Stephen J.; Chiers, Koen; Duchateau, Luc; Franco-Obregón, Alfredo

2014-01-01

370

Accelerated intimal hyperplasia in aortocoronary internal mammary vein grafts in minipigs  

PubMed Central

Background More than 50% of aortocoronary saphenous vein grafts are occluded 10 years after surgery. Intimal hyperplasia is the initial critical step in the progression toward occlusion. Internal mammary veins, which are physiologically prone to less hydrostatic pressure, may undergo an accelerated progression to intimal hyperplasia and thus be suitable for investigation of the mechanisms of aortocoronary vein graft disease. Methods Six minipigs underwent aortocoronary bypass grafting using standard cardiopulmonary bypass and cardioplegic arrest. Mammary vein were grafted in a reversed manner from ascending aorta to left anterior descending coronary artery (LAD). The proximal LAD was ligated, rendering the anterior left ventricle vein graft-dependent. Minipigs were killed after 4 weeks, and vein grafts were harvested. Histological and immunohistological investigation were performed with respect to morphometric analysis, endothelial damage/dysfunction (v-Willebrand-factor (vWF)), smooth muscle cells (?-smooth actin) and proliferation rate (proliferation marker Ki 67). Results Mean intimal area of vein grafts was increased compared to ungrafted mammary veins. Intimal hyperplasia in vein grafts was characterized by massive accumulation of smooth muscle cells with a high proliferation rate and endothelial perturbation. Significant (p = 0.001) intimal hyperplasia of the grafted mammary vein compared to the ungrafted mammary vein was found. These changes were absent in ungrafted mammary veins. Conclusion The present study demonstrates a pig model of aortocoronary vein graft intimal hyperplasia which is characterized by an accelerated progression within internal mammary veins. The model is suitable to investigate the pathophysiology of aortocoronary vein graft intimal hyperplasia as well as therapeutic approaches. PMID:18445288

Popov, Aron Frederik; Dorge, Hilmar; Hinz, Jose; Schmitto, Jan Dieter; Stojanovic, Tomislav; Seipelt, Ralf; Didilis, Vassilios; Schoendube, Friedrich Albert

2008-01-01

371

Nitric oxide is less effective at inhibiting neointimal hyperplasia in spontaneously hypertensive rats.  

PubMed

Exogenous administration of nitric oxide (NO) markedly decreases neointimal hyperplasia following arterial injury in several animal models. However, the effect of NO on neointimal hyperplasia in hypertension remains unknown. Here, we employ the spontaneously hypertensive rat (SHR) strain, inbred from Wistar Kyoto (WKY) rats, and the carotid artery balloon injury model to assess the effects of NO on neointimal hyperplasia development. 2weeks after arterial injury, we showed that both rat strains developed similar levels of neointimal hyperplasia, but local administration of NO was less effective at inhibiting neointimal hyperplasia in the SHR compared to WKY rats (58% vs. 79%, P<0.001). Interestingly, local administration of NO did not affect systemic blood pressure in either rat strain. Compared to WKY, the SHR displayed more proliferation in the media and adventitia following balloon injury, as measured by BrdU incorporation. The SHR also showed more inflammation in the adventitia after injury, as well as more vasa vasorum, than WKY rats. NO treatment reduced the vasa vasorum in the SHR but not WKY rats. Finally, while NO decreased both injury-induced proliferation and inflammation in the SHR, it did not return these parameters to levels seen in WKY rats. We conclude that NO is less effective at inhibiting neointimal hyperplasia in the SHR than WKY rats. This may be due to increased scavenging of NO in the SHR, leading to diminished bioavailability of NO. These data will help to develop novel NO-based therapies that will be equally effective in both normotensive and hypertensive patient populations. PMID:24149190

Tsihlis, Nick D; Vavra, Ashley K; Martinez, Janet; Lee, Vanessa R; Kibbe, Melina R

2013-11-30

372

Nitric Oxide is Less Effective at Inhibiting Neointimal Hyperplasia in Spontaneously Hypertensive Rats  

PubMed Central

Exogenous administration of nitric oxide (NO) markedly decreases neointimal hyperplasia following arterial injury in several animal models. However, the effect of NO on neointimal hyperplasia in hypertension remains unknown. Here, we employ the spontaneously hypertensive rat (SHR) strain, inbred from Wistar Kyoto (WKY) rats, and the carotid artery balloon injury model to assess the effects of NO on neointimal hyperplasia development. Two weeks after arterial injury, we showed that both rat strains developed similar levels of neointimal hyperplasia, but local administration of NO was less effective at inhibiting neointimal hyperplasia in the SHR compared to WKY rats (58% vs. 79%, P<0.001). Interestingly, local administration of NO did not affect systemic blood pressure in either rat strain. Compared to WKY, the SHR displayed more proliferation in the media and adventitia following balloon injury, as measured by BrdU incorporation. The SHR also showed more inflammation in the adventitia after injury, as well as more vasa vasorum, than WKY rats. NO treatment reduced the vasa vasorum in the SHR but not WKY rats. Finally, while NO decreased both injury-induced proliferation and inflammation in the SHR, it did not return these parameters to levels seen in WKY rats. We conclude that NO is less effective at inhibiting neointimal hyperplasia in the SHR than WKY rats. This may be due to increased scavenging of NO in the SHR, leading to diminished bioavailability of NO. These data will help to develop novel NO-based therapies that will be equally effective in both normotensive and hypertensive patient populations. PMID:24149190

Tsihlis, Nick D.; Vavra, Ashley K.; Martinez, Janet; Lee, Vanessa R.; Kibbe, Melina R.

2013-01-01

373

[Antiproliferative effect of polar lipids of maral antlers and peat in prostate benign hyperplasia model].  

PubMed

Lipids isolated from maral antlers and peat decreased the prostate posterior and lateral lobule mass and normalized its acinar and stromal histological structure, reduced protein content, decreased formation of lipid peroxidation products, and intensified antioxidant protection in homogenates, decreased prolactine and 5a-dihydrotestosterone blood level, and increased testosterone blood content in male rats of late reproductive age with prostate benign hyperplasia model caused by sulpiride injections. Polar lipids of maral antlers and peat more effectively suppress prostate hyperplasia and hyperprolactinemia development in comparison to the action of Serenoa repens extract (permixon). PMID:23901466

Vengerovski?, A I; Burkova, V N; Iudina, N V; Iatsenkov, A I

2013-01-01

374

The Nitroreductase System of Inducible Targeted Ablation Facilitates Cell-specific Regenerative Studies in Zebrafish  

PubMed Central

At the turn of the 20th century, classical regenerative biology – the study of organismal/tissue/limb regeneration in animals such as crayfish, snails, and planaria – garnered much attention. However, scientific luminaries such as Thomas Hunt Morgan eventually turned to other fields after concluding that inquiries into regenerative mechanisms were largely intractable beyond observational intrigues. The field of regeneration has enjoyed a resurgence in research activity at the turn of the 21st century, in large part due to “the promise” of cultured stem cells regarding reparative therapeutic approaches. Additionally, genomics-based methods that allow sophisticated genetic/molecular manipulations to be carried out in nearly any species have extended organismal regenerative biology well beyond observational limits. Throughout its history, complex paradigms such as limb regeneration – involving multiple tissue/cell types, thus, potentially multiple stem cell subtypes – have predominated the regenerative biology field. Conversely, cellular regeneration – the replacement of specific cell types – has been studied from only a few perspectives (predominantly muscle and mechanosensory hair cells). Yet, many of the degenerative diseases that regenerative biology hopes to address involve the loss of individual cell types; thus, a primary emphasis of the embryonic/induced stem cell field is defining culture conditions which promote cell-specific differentiation. Here we will discuss recent methodological approaches that promote the study of cell-specific regeneration. Such paradigms can reveal how the differentiation of specific cell types and regenerative potential of discrete stem cell niches are regulated. In particular, we will focus on how the nitroreductase (NTR) system of inducible targeted cell ablation facilitates: 1) large-scale genetic and chemical screens for identifying factors that regulate regeneration and, 2) in vivo time-lapse imaging experiments aimed at investigating regenerative processes more directly. Combining powerful screening and imaging technologies with targeted ablation systems can expand our understanding of how individual stem cell niches are regulated. The former approach promotes the development of therapies aimed at enhancing regenerative potentials in humans, the latter facilitates investigation of phenomena that are otherwise difficult to resolve, such as the role of cellular transdifferentiation or the innate immune system in regenerative paradigms. PMID:23542552

White, David T.; Mumm, Jeff S.

2013-01-01

375

The nitroreductase system of inducible targeted ablation facilitates cell-specific regenerative studies in zebrafish.  

PubMed

At the turn of the 20th century, classical regenerative biology--the study of organismal/tissue/limb regeneration in animals such as crayfish, snails, and planaria--garnered much attention. However, scientific luminaries such as Thomas Hunt Morgan eventually turned to other fields after concluding that inquiries into regenerative mechanisms were largely intractable beyond observational intrigues. The field of regeneration has enjoyed a resurgence in research activity at the turn of the 21st century, in large part due to "the promise" of cultured stem cells regarding reparative therapeutic approaches. Additionally, genomics-based methods that allow sophisticated genetic/molecular manipulations to be carried out in nearly any species have extended organismal regenerative biology well beyond observational limits. Throughout its history, complex paradigms such as limb regeneration--involving multiple tissue/cell types, thus, potentially multiple stem cell subtypes--have predominated the regenerative biology field. Conversely, cellular regeneration--the replacement of specific cell types--has been studied from only a few perspectives (predominantly muscle and mechanosensory hair cells). Yet, many of the degenerative diseases that regenerative biology hopes to address involve the loss of individual cell types; thus, a primary emphasis of the embryonic/induced stem cell field is defining culture conditions which promote cell-specific differentiation. Here we will discuss recent methodological approaches that promote the study of cell-specific regeneration. Such paradigms can reveal how the differentiation of specific cell types and regenerative potential of discrete stem cell niches are regulated. In particular, we will focus on how the nitroreductase (NTR) system of inducible targeted cell ablation facilitates: (1) large-scale genetic and chemical screens for identifying factors that regulate regeneration and (2) in vivo time-lapse imaging experiments aimed at investigating regenerative processes more directly. Combining powerful screening and imaging technologies with targeted ablation systems can expand our understanding of how individual stem cell niches are regulated. The former approach promotes the development of therapies aimed at enhancing regenerative potentials in humans, the latter facilitates investigation of phenomena that are otherwise difficult to resolve, such as the role of cellular transdifferentiation or the innate immune system in regenerative paradigms. PMID:23542552

White, David T; Mumm, Jeff S

2013-08-15

376

Optimization of the alignment sensitivity and energy stability of the NIF regenerative amplifier cavity/011  

SciTech Connect

The work to improve the energy stability of the regenerative amplifier (`regen`) for the National Ignition Facility is described. This includes a fast feed-forward system, designed to regulate the output energy of the regen by monitoring how quickly a pulse builds up over many round trips. Shot-to-shot energy fluctuations of all elements prior to (and including) the regen may be compensated for in this way, at the expense of a loss of approximately 50%. Also included is a detailed study into the alignment sensitivity of the regen cavity, with the goal of quantifying the effect of misalignment on the output energy. This is done by calculating the displacement of the eigenmode by augmenting the cavity ABCD matrix with the misalignment matrix elements, E, F. In this way, cavity misalignment issues due to thermal loading of the gain medium are investigated. Alternative cavity designs, which reduce the alignment sensitivity and therefore the energy drift over periods of continuous operation, are considered. Alterations to the amplifier head design are also considered.

Hopps, N. W., Atomic Weapons Research Establishment, Aldermaston, Great Britain

1998-06-24

377

Inflammation and Its Correlates in Regenerative Wound Healing: An Alternate Perspective.  

PubMed

Objective: The wound healing response may be viewed as partially overlapping sets of two physiological processes, regeneration and wound repair with the former overrepresented in some lower species such as newts and the latter more typical of mammals. A robust and quantitative model of regenerative healing has been described in Murphy Roths Large (MRL) mice in which through-and-through ear hole wounds in the ear pinna leads to scarless healing and replacement of all tissue through blastema formation and including cartilage. Since these mice are naturally autoimmune and display many aspects of an enhanced inflammatory response, we chose to examine the inflammatory status during regenerative ear hole closure and observed that inflammation has a clear positive effect on regenerative healing. Approach: The inflammatory gene expression patterns (Illumina microarrays) of early healing ear tissue from regenerative MRL and nonregenerative C57BL/6 (B6) strains are presented along with a survey of innate inflammatory cells found in this tissue type pre and postinjury. The role of inflammation on healing is tested using a COX-2 inhibitor. Innovation and Conclusion: We conclude that (1) enhanced inflammation is consistent with, and probably necessary, for a full regenerative response and (2) the inflammatory gene expression and cell distribution patterns suggest a novel mast cell population with markers found in both immature and mature mast cells that may be a key component of regeneration. PMID:25207202

Gourevitch, Dmitri; Kossenkov, Andrew V; Zhang, Yong; Clark, Lise; Chang, Celia; Showe, Louise C; Heber-Katz, Ellen

2014-09-01

378

Inflammation and Its Correlates in Regenerative Wound Healing: An Alternate Perspective  

PubMed Central

Objective: The wound healing response may be viewed as partially overlapping sets of two physiological processes, regeneration and wound repair with the former overrepresented in some lower species such as newts and the latter more typical of mammals. A robust and quantitative model of regenerative healing has been described in Murphy Roths Large (MRL) mice in which through-and-through ear hole wounds in the ear pinna leads to scarless healing and replacement of all tissue through blastema formation and including cartilage. Since these mice are naturally autoimmune and display many aspects of an enhanced inflammatory response, we chose to examine the inflammatory status during regenerative ear hole closure and observed that inflammation has a clear positive effect on regenerative healing. Approach: The inflammatory gene expression patterns (Illumina microarrays) of early healing ear tissue from regenerative MRL and nonregenerative C57BL/6 (B6) strains are presented along with a survey of innate inflammatory cells found in this tissue type pre and postinjury. The role of inflammation on healing is tested using a COX-2 inhibitor. Innovation and Conclusion: We conclude that (1) enhanced inflammation is consistent with, and probably necessary, for a full regenerative response and (2) the inflammatory gene expression and cell distribution patterns suggest a novel mast cell population with markers found in both immature and mature mast cells that may be a key component of regeneration. PMID:25207202

Gourevitch, Dmitri; Kossenkov, Andrew V.; Zhang, Yong; Clark, Lise; Chang, Celia; Showe, Louise C.; Heber-Katz, Ellen

2014-01-01

379

Stress Incontinence in the Era of Regenerative Medicine: Reviewing the Importance of the Pudendal Nerve  

PubMed Central

Purpose Regenerative medicine will likely facilitate improved stress urinary incontinence (SUI) treatment via restoration of its neurogenic, myogenic, and structural etiologies. Understanding these pathophysiologies and how each can optimally benefit from cellular, molecular, and minimally invasive therapies will become necessary. While stem cells in sphincteric deficiency dominate the regenerative urology literature, little is published on pudendal nerve (PN) regeneration or other regenerative targets. The purpose of this review is to discuss regenerative therapies for PN injury in SUI. Materials and Methods A PubMed® search for pudendal nerve combined individually with regeneration, injury, electrophysiology, measurement, and activity produced a combined but non-independent 621 results. English language articles were reviewed by title for relevance, identifying a combined but non-independent 68 articles. A subsequent Google Scholar® searchand review of references in articles obtained aided in broadening discussion. Results Electrophysiological studies associate PN dysfunction with SUI clinically and assess PN regeneration functionally while animal models provide physiological insight. Stem cell treatment has improved continence clinically while ex vivo sphincteric bulk and muscle function gains have been noted in the laboratory. Stem cells, neurotrophic factors, and electrical stimulation each benefit PN regeneration in animal models. Conclusions Most regenerative work to date focuses on stem cells restoring sphincteric function and bulk, but whether a sphincter denervated by PN injury will benefit is unclear. Regeneration of the PN appears possible through minimally invasive therapies that exhibit significant clinical potential. Treating poor central control and coordination of the neuromuscular continence mechanism remains another challenge. PMID:23376143

Gill, Bradley C.; Damaser, Margot S.; Vasavada, Sandip P.; Goldman, Howard B.

2014-01-01

380

Effects of silodosin and tamsulosin on the urethra and cardiovascular system in young and old dogs with benign prostatic hyperplasia.  

PubMed

We examined whether the effects (efficacy on the urethra and hypotension) of silodosin (alpha(1A)-adrenoceptor antagonist) and tamsulosin (alpha(1A+1D)-adrenoceptor antagonist) in dogs with benign prostatic hyperplasia altered with age. We used young and old dogs, diagnosed as having benign prostatic hyperplasia by veterinarian's palpation. Under anesthesia, the increase in intraurethral pressure evoked by hypogastric nerve stimulation was measured, together with the level of systemic mean blood pressure. Each drug was administered intravenously in progressively increasing doses. At the end of the experiment, the prostate was isolated from each dog, then weighed and investigated pathologically to confirm benign prostatic hyperplasia. The wet weight of the prostate was greater in old dogs with benign prostatic hyperplasia than in young dogs with benign prostatic hyperplasia. By light microscopy, hyperplasia in the prostatic epithelium was confirmed in both groups. Silodosin (0.3-300 microg/kg) dose-dependently inhibited the hypogastric nerve stimulation-induced increase in intraurethral pressure (without significant hypotensive effects) in both young and old dogs with benign prostatic hyperplasia. Tamsulosin (0.3-300 microg/kg) also dose-dependently inhibited the intraurethral pressure increase in both groups, but it had a hypotensive effect that was significantly greater in old than in young dogs with benign prostatic hyperplasia. In conclusion, as regards the effect of silodosin on intraurethral pressure, potency was similar between young and old dogs with benign prostatic hyperplasia, and it was without significant hypotensive effects. We therefore suggest that silodosin might be a good medication for lower urinary tract symptoms in patients with benign prostatic hyperplasia in all age groups. PMID:19389393

Kobayashi, Shinya; Tomiyama, Yoshitaka; Tatemichi, Satoshi; Hoyano, Yuji; Kobayashi, Mamoru; Yamazaki, Yoshinobu

2009-06-24

381

Cyclin D2 Overexpression in Transgenic Mice Induces Thymic and Epidermal Hyperplasia whereas Cyclin D3 Expression Results Only in Epidermal Hyperplasia  

PubMed Central

In a previous report, we described the effects of cyclin D1 expression in epithelial tissues of transgenic mice. To study the involvement of D-type cyclins (D1, D2, and D3) in epithelial growth and differentiation and their putative role as oncogenes in skin, transgenic mice were developed which carry cyclin D2 or D3 genes driven by a keratin 5 promoter. As expected, both transgenic lines showed expression of these proteins in most of the squamous tissues analyzed. Epidermal proliferation increased in transgenic animals and basal cell hyperplasia was observed. All of the animals also had a minor thickening of the epidermis. The pattern of expression of keratin 1 and keratin 5 indicated that epidermal differentiation was not affected. Transgenic K5D2 mice developed mild thymic hyperplasia that reversed at 4 months of age. On the other hand, high expression of cyclin D3 in the thymus did not produce hyperplasia. This model provides in vivo evidence of the action of cyclin D2 and cyclin D3 as mediators of proliferation in squamous epithelial cells. A direct comparison among the three D-type cyclin transgenic mice suggests that cyclin D1 and cyclin D2 have similar roles in epithelial thymus cells. However, overexpression of each D-type cyclin produces a distinct phenotype in thymic epithelial cells. PMID:10980142

Rodriguez-Puebla, Marcelo L.; LaCava, Margaret; Miliani de Marval, Paula L.; Jorcano, Jose L.; Richie, Ellen R.; Conti, Claudio J.

2000-01-01

382

Adaptive scapula bone remodeling computational simulation: Relevance to regenerative medicine  

SciTech Connect

Shoulder arthroplasty success has been attributed to many factors including, bone quality, soft tissue balancing, surgeon experience, and implant design. Improved long-term success is primarily limited by glenoid implant loosening. Prosthesis design examines materials and shape and determines whether the design should withstand a lifetime of use. Finite element (FE) analyses have been extensively used to study stresses and strains produced in implants and bone. However, these static analyses only measure a moment in time and not the adaptive response to the altered environment produced by the therapeutic intervention. Computational analyses that integrate remodeling rules predict how bone will respond over time. Recent work has shown that subject-specific two- and three dimensional adaptive bone remodeling models are feasible and valid. Feasibility and validation were achieved computationally, simulating bone remodeling using an intact human scapula, initially resetting the scapular bone material properties to be uniform, numerically simulating sequential loading, and comparing the bone remodeling simulation results to the actual scapula’s material properties. Three-dimensional scapula FE bone model was created using volumetric computed tomography images. Muscle and joint load and boundary conditions were applied based on values reported in the literature. Internal bone remodeling was based on element strain-energy density. Initially, all bone elements were assigned a homogeneous density. All loads were applied for 10 iterations. After every iteration, each bone element’s remodeling stimulus was compared to its corresponding reference stimulus and its material properties modified. The simulation achieved convergence. At the end of the simulation the predicted and actual specimen bone apparent density were plotted and compared. Location of high and low predicted bone density was comparable to the actual specimen. High predicted bone density was greater than actual specimen. Low predicted bone density was lower than actual specimen. Differences were probably due to applied muscle and joint reaction loads, boundary conditions, and values of constants used. Work is underway to study this. Nonetheless, the results demonstrate three dimensional bone remodeling simulation validity and potential. Such adaptive predictions take physiological bone remodeling simulations one step closer to reality. Computational analyses are needed that integrate biological remodeling rules and predict how bone will respond over time. We expect the combination of computational static stress analyses together with adaptive bone remodeling simulations to become effective tools for regenerative medicine research.

Sharma, Gulshan B., E-mail: gbsharma@ucalgary.ca [Emory University, Department of Radiology and Imaging Sciences, Spine and Orthopaedic Center, Atlanta, Georgia 30329 (United States); University of Pittsburgh, Swanson School of Engineering, Department of Bioengineering, Pittsburgh, Pennsylvania 15213 (United States); University of Calgary, Schulich School of Engineering, Department of Mechanical and Manufacturing Engineering, Calgary, Alberta T2N 1N4 (Canada); Robertson, Douglas D., E-mail: douglas.d.robertson@emory.edu [Emory University, Department of Radiology and Imaging Sciences, Spine and Orthopaedic Center, Atlanta, Georgia 30329 (United States); University of Pittsburgh, Swanson School of Engineering, Department of Bioengineering, Pittsburgh, Pennsylvania 15213 (United States)

2013-07-01

383

The link between injury-induced stress and regenerative phenomena: A cellular and genetic synopsis.  

PubMed

Injury is an inescapable phenomenon of life that affects animals at every physiological level. Yet, some animals respond to injury by rebuilding the damaged tissues whereas others are limited to scarring. Elucidating how a tissue insult from wounding leads to a regenerative response at the genetic level is essential to make regenerative advantages translational. It has become clear that animals with regenerative abilities recycle developmental programs after injury, reactivating genes that have lied dormant throughout adulthood. The question that is critical to our understanding of regeneration is how a specific set of developmentally important genes can be reactivated only after an acute tissue insult. Here, we review how injury-induced cellular stresses such as hypoxic, oxidative, and mechanical stress may contribute to the genomic and epigenetic changes that promote regeneration in animals. This article is part of a Special Issue entitled: Stress as a fundamental theme in cell plasticity. PMID:25088176

Erler, Piril; Monaghan, James R

2014-08-01

384

Modeling and optimization of a regenerative fuel cell system using the ASPEN process simulator  

NASA Technical Reports Server (NTRS)

The Hydrogen-Oxygen Regenerative Fuel Cell System was identified as a key component for energy storage in support of future lunar missions. Since the H2-O2 regenerative electrochemical conversion technology has not yet been tested in space applications, it is necessary to implement predictive techniques to develop initial feasible system designs. The ASPEN simulation software furnishes a constructive medium for analyzing and for optimizing such systems. A rudimentary regenerative fuel cell system design was examined using the ASPEN simulator and this modular approach allows for easy addition of supplementary ancillary components and easy integration with life support systems. The modules included in the preliminary analyses may serve as the fundamental structure for more complicated energy storage systems.

Maloney, Thomas M.; Leibecki, Harold F.

1990-01-01

385

Modeling and optimization of a regenerative fuel cell system using the ASPEN process simulator  

NASA Technical Reports Server (NTRS)

The Hydrogen-Oxygen Regenerative Fuel Cell System was identified as a key component for energy storage in support of future lunar missions. Since the H2-O2 regenerative electrochemical conversion technology has not yet been tested in space applications, it is necessary to implement predictive techniques to develop initial feasible system designs. The ASPEN simulation software furnishes a constructive medium for analyzing and optimizing such systems. A rudimentary regenerative fuel cell system design was examined using the ASPEN simulator and this modular approach allows for easy addition of supplementary ancillary components and easy integration with life support systems. The modules included in the preliminary analyses may serve as the fundamental structure for more complicated energy storage systems.

Maloney, Thomas M.; Leibecki, Harold F.

1990-01-01

386

Multi-walled carbon nanotubes inhibit regenerative axon growth of dorsal root ganglia neurons of mice  

PubMed Central

Recent observations have demonstrated that nanomaterials may be toxic to human tissue. While the ability of nano-scaled particulate matter is known to cause a range of problems in respiratory system, recent observations suggest that the nervous system may be vulnerable as well. In the current paper we asked whether exposure of primary neuronal cell cultures to nanoparticles might compromise regenerative axon growth. Regenerative response was triggered by performing a conditioning lesion of sciatic nerve five days prior to collection of dorsal root ganglia (DRG). DRG neurons were plated at a low density and incubated with multi-walled carbon nanotubes (MWCNT) (0.1 – 10 ?g/ml in 10% of surfactant in saline) overnight. The experiments showed that exposure of DRG cultures to MWCNT significantly impaired regenerative axonogenesis without concomitant cell death. These results indicate that MWNCTs may have detrimental effect on nerve regeneration and may potentially trigger axonal pathology. PMID:22172934

Wu, Di; Pak, Elena S.; Wingard, Christopher J.; Murashov, Alexander K.

2012-01-01

387

A New Animal Model to Study Intimal Hyperplasia in Arteriovenous Fistulas  

Microsoft Academic Search

Background. Intimal hyperplasia (IH) plays a key role in the failure of arteriovenous (AV) fistulas. The animal models available to study IH in AV fistulas are expensive and do not mimic the development of truly stenotic IH. In this study we examined whether goats are a more suitable model to study IH in AV fistulas.Materials and Methods. Thirteen direct and

M. S. Lemson; M. J. A. P. Daemen; J. H. M. Tordoir

1999-01-01

388

Gender Change from Female to Male in Classical Congenital Adrenal Hyperplasia  

Microsoft Academic Search

The psychoendocrinology of the development of normal gender identity and its variations is poorly understood. Studies of gender development in individuals born with endocrinologically well-characterized intersex conditions are heuristically valuable for the disaggregation of factors that are acting in concert during normal development. Four 46,XX individuals with classical congenital adrenal hyperplasia (CAH) and atypical gender identity entered a comprehensive research

Heino F. L. Meyer-Bahlburg; Rhoda S. Gruen; Maria I. New; Jennifer J. Bell; Akira Morishima; Mona Shimshi; Yvette Bueno; Ileana Vargas; Susan W. Baker

1996-01-01

389

Multiplex Minisequencing of the 21Hydroxylase Gene as a Rapid Strategy to Confirm Congenital Adrenal Hyperplasia  

Microsoft Academic Search

Background: Congenital adrenal hyperplasia (CAH) is a frequent autosomal recessive disease, with a wide range of clinical manifestations, most commonly attributable to mutations in the 21-hydroxylase gene (CYP21). Large gene deletions, large gene conversions, a small 8-base- pair deletion, and eight point mutations in CYP21 ac- count for 95% of all enzyme deficiencies. We devel- oped a new strategy for

Nils Krone; Andreas Braun; Stefanie Weinert; Michael Peter; Adelbert A. Roscher; Carl-Joachim Partsch; Wolfgang G. Sippell

2002-01-01

390

The role of phytotherapy in treating lower urinary tract symptoms and benign prostatic hyperplasia  

Microsoft Academic Search

Despite their traditional popularity in many European countries and their increasing use as dietary supplements in the United States, the role of phytotherapeutic agents in treating lower urinary tract symptoms (LUTS) and benign prostatic hyperplasia (BPH) is continuously debated. If strict criteria of evidence-based medicine are applied, the available data have not yet provided clear evidence of efficacy for most

Kurt Dreikorn

2002-01-01

391

Intravascular papillary endothelial hyperplasia (Masson's hemangioma) presenting as a lateral neck mass.  

PubMed

Intravascular papillary endothelial hyperplasia (Masson's hemangioma) is a benign disease of vascular origin characterized by exuberant endothelial proliferation in normal blood vessels.The most important feature of the disease is its resemblance to hemangiosarcoma and the resulting possible radiologic misinterpretation. We present the radiologic findings in a 45-year-old woman presenting a neck mass extending to the thoracic cavity. PMID:19358481

Yücesoy, C; Coban, G; Yilmazer, D; Oztürk, E; Hekimo?lu, B

2009-01-01

392

Villous atrophy with crypt hyperplasia in malignant histiocytosis of the nose  

Microsoft Academic Search

Intestinal changes, mainly in the jejunum, were investigated in 13 cases of malignant histiocytosis at necropsy and who had presented as lethal midline granuloma. Villous atrophy with crypt hyperplasia was observed in all cases, and a proliferation of atypical histiocytes was observed in seven cases. In the remaining cases, histiocytes with normal morphology increased in number. These findings showed that

K Aozasa

1982-01-01

393

IL-17 suppresses immune effector functions in human papillomavirus-associated epithelial hyperplasia.  

PubMed

Persistent infection with high-risk human papillomaviruses (HPV) causes epithelial hyperplasia that can progress to cancer and is thought to depend on immunosuppressive mechanisms that prevent viral clearance by the host. IL-17 is a cytokine with diverse functions in host defense and in the pathology of autoimmune disorders, chronic inflammatory diseases, and cancer. We analyzed biopsies from patients with HPV-associated cervical intraepithelial neoplasia grade 2/3 and murine skin displaying HPV16 E7 protein-induced epithelial hyperplasia, which closely models hyperplasia in chronic HPV lesions. Expression of IL-17 and IL-23, a major inducer of IL-17, was elevated in both human HPV-infected and murine E7-expressing lesions. Using a skin-grafting model, we demonstrated that IL-17 in HPV16 E7 transgenic skin grafts inhibited effective host immune responses against the graft. IL-17 was produced by CD3(+) T cells, predominantly CD4(+) T cells in human, and CD4(+) and ?? T cells in mouse hyperplastic lesions. IL-23 and IL-1?, but not IL-18, induced IL-17 production in E7 transgenic skin. Together, these findings demonstrate an immunosuppressive role for IL-17 in HPV-associated epithelial hyperplasia and suggest that blocking IL-17 in persistent viral infection may promote antiviral immunity and prevent progression to cancer. PMID:25063870

Gosmann, Christina; Mattarollo, Stephen R; Bridge, Jennifer A; Frazer, Ian H; Blumenthal, Antje

2014-09-01

394

Cystinosis and gingival hyperplasia: demonstration of cystine crystals in gingival tissue and unusual aspects of management.  

PubMed

A patient with nephropathic cystinosis developed gingival hyperplasia secondary to cyclosporine-A therapy for his renal allograft. The typical crystals described on electron microscopic examination of other organs of patients with cystinosis were seen in the resected gingiva of this patient. These crystals have not been previously described in this location. Unusual aspects of the management of this patient are discussed. PMID:7877086

Heller, A N; Heller, D S; Schwimmer, A; Gordon, R E; Cambria, R J

1994-12-01

395

Regeneration in pig livers by compensatory hyperplasia induces high levels of telomerase activity  

Microsoft Academic Search

BACKGROUND: Several highly proliferative human cells transiently activate telomerase, a ribonucleoprotein with reverse transcriptase activity, to counterbalance replication-associated telomere erosion and to increase stress resistance. Quiescent human hepatocytes exhibit very low or undetectable levels of telomerase activity. However, hepatocytes display a remarkable proliferative capability following liver injury. To investigate whether liver regeneration by compensatory hyperplasia is associated with telomerase activation,

Henning Wege; Anett Müller; Lars Müller; Susan Petri; Jörg Petersen; Christian Hillert

2007-01-01

396

Low Molecular Weight Fucoidan Prevents Neointimal Hyperplasia in Rabbit Iliac Artery In-Stent Restenosis Model  

Microsoft Academic Search

Objective—Smooth muscle cell (SMC) proliferation within the intima is regulated by heparan sulfates. We studied a low molecular weight (LMW) fucoidan (sulfated polysaccharide from brown seaweed) on SMC proliferation in vitro and intimal hyperplasia in vivo. Methods and Results—In vitro study revealed that LMW fucoidan reduces rabbit SMC proliferation and is internalized in SMC perinuclear vesicles. On rabbit iliac arteries

Jean-François Deux; Anne Meddahi-Pellé; Alain F. Le Blanche; Laurent J. Feldman; Sylvia Colliec-Jouault; Françoise Brée; Frank Boudghène; Jean-Baptiste Michel; Didier Letourneur

397

Decision Aids for Benign Prostatic Hyperplasia: Applicability across Race and Education  

Microsoft Academic Search

Background\\/Method. Decision aids have not been widely tested in diverse audiences. The authors conducted inter- views in a 2 2 race by education design with participants who were 50 years old (n = 188). The decision aid was a be- nign prostatic hyperplasia videotape. Results. There was an increase in knowledge equal in all groups, with baseline knowledge higher in

David R. Rovner; Celia E. Wills; Vence Bonham; Gilbert Williams; Janet Lillie; Karen Kelly-Blake; Mark V. Williams; Margaret Holmes-Rovner

2004-01-01

398

Treatment preference patterns during a videotape decision aid for benign prostatic hyperplasia (BPH)  

Microsoft Academic Search

ObjectiveAs part of a study of men's responses to a videotape decision aid [Rovner DR, Wills CE, Bonham V, Williams G, Lillie J, Kelly-Blake K, Williams MV, Holmes-Rovner M. Decision aids for benign prostatic hyperplasia: applicability across race and education. Med Decis Making 2004;24:359–66], preferences for BPH treatment options were assessed.

Celia E. Wills; Margaret Holmes-Rovner; David Rovner; Janet Lillie; Karen Kelly-Blake; Vence Bonham; Gilbert Williams

2006-01-01

399

Clinical study of the efficiency and safety of afala in patients with benign prostatic hyperplasia.  

PubMed

The use of afala in patients with benign prostatic hyperplasia and moderate urination disturbances reduced the symptoms of the disease, improved urodynamic parameters, and increased quality of life. Clinical efficiency of afala was comparable with the efficiency of Serenoa repens extract (reference preparation). PMID:20027354

Savel'eva, K V; Kachanova, M V; Pavlov, V N; Kazikhinurov, R A; Frolov, M Yu; Mukhin, A B; Udut, V V; Yurmazov, Z A; Dugina, Yu L; Sergeeva, S A; Epshtein, O I

2009-08-01

400

Testicular Adrenal Rest Tumor in 11-Beta-Hydroxylase Deficiency Driven Congenital Adrenal Hyperplasia  

PubMed Central

Testicular adrenal rest tumors (TART) occur often as asymptomatic nodules in corticotropin-dependent lesions aberrant adrenal tissue in congenital adrenal hyperplasia (CAH) patients. The present manuscript is about an unusual case of a 16-year-old CAH patient due to 11?-hydroxylase deficiency. He underwent testicle biopsy because of testicle tumor suspicion and diagnosed with TART. PMID:24741421

Sönmez, Mehmet Giray; Ünlü, Ya?ar; Karata?, Tuna; Tekinarslan, Erdem; Sümer, Alpay

2014-01-01

401

Focal nodular hyperplasia of the liver with the lumbo-costovertebral syndrome.  

PubMed

Congenital lumbar hernia is uncommon in children; only 42 cases have been reported. A newborn girl with congenital superior lumbar hernia associated with lumbo-costovertebral syndrome is described. Associated features include focal nodular hyperplasia of the liver, absent right kidney and hydrocephalus. PMID:8887102

al-Salem, A H; Abu-Srair, H; Qaissaruddin, S

1996-09-01

402

Carrier Frequency of Congenital Adrenal Hyperplasia (21Hydroxylase Deficiency) in a Middle European Population  

Microsoft Academic Search

Based on newborn screening data, the carrier frequency of congenital adrenal hyperplasia (CAH) in the general popula- tion has been estimated to be 1:55. The higher CAH frequency (particularly of milder forms of the disease) reported for cer- tain populations including Yugoslavs (1.6%) relates to popu- lation genetic and hormonal data. However, so far, true car- rier frequency for CAH

S. M. Baumgartner-Parzer; P. Nowotny; G. Heinze; W. Waldhausl; H. Vierhapper

2004-01-01

403

Timing and Type of Glucocorticoid Replacement in Adult Congenital Adrenal Hyperplasia  

Microsoft Academic Search

Congenital adrenal hyperplasia (CAH) is one of the commonest inherited diseases. Treatment during childhood is directed towards obtaining normal growth. There is an extensive literature on management of CAH during childhood but little published on how patients should be treated as adults. CAH results in increased adrenocorticotropic hormone levels driving the adrenal to produce cortisol and thereby excessive cortisol precursors

R. J. M. Ross; A. Rostami-Hodjegan

2005-01-01

404

Regenerative therapy as an adjunct to periapical surgery: a case report.  

PubMed

Large periapical defects may adversely affect the success rate of endodontic surgery. Use of regenerative therapy may enhance the prognosis of such teeth. A case of traumatized upper anterior teeth with infected radicular cyst and associated sinus tract reported to the dental hospital. A periradicular surgical procedure was performed to remove the nonhealing pathological tissue. To augment the repair a bioactive bone graft material was placed. Six months interim results showed positive outcome of application of graft. How to cite this article: Chaturvedy V, Chaturvedy S. Regenerative Therapy as an Adjunct to Periapical Surgery: A Case Report. Int J Clin Pediatr Dent 2012;5(1):75-77. PMID:25206140

Chaturvedy, Vivek; Chaturvedy, Shefali

2012-01-01

405

Initial Design and Construction of a Mobil Regenerative Fuel Cell System  

NASA Technical Reports Server (NTRS)

The design and initial construction of a mobile regenerative power system is described. The main components of the power system consists of a photovoltaic array, regenerative fuel cell and electrolyzer. The system is mounted on a modified landscape trailer and is completely self contained. An operational analysis is also presented that shows predicted performance for the system at various times of the year. The operational analysis consists of performing an energy balance on the system based on array output and total desired operational time.

Colozza, Anthony J.; Maloney, Thomas; Hoberecht, Mark (Technical Monitor)

2003-01-01

406

Regenerative Therapy as an Adjunct to Periapical Surgery: A Case Report  

PubMed Central

ABSTRACT Large periapical defects may adversely affect the success rate of endodontic surgery. Use of regenerative therapy may enhance the prognosis of such teeth. A case of traumatized upper anterior teeth with infected radicular cyst and associated sinus tract reported to the dental hospital. A periradicular surgical procedure was performed to remove the nonhealing pathological tissue. To augment the repair a bioactive bone graft material was placed. Six months interim results showed positive outcome of application of graft. How to cite this article: Chaturvedy V, Chaturvedy S. Regenerative Therapy as an Adjunct to Periapical Surgery: A Case Report. Int J Clin Pediatr Dent 2012;5(1):75-77. PMID:25206140

Chaturvedy, Shefali

2012-01-01

407

Construction of narrow-band regenerative amplifier for momentum imaging spectroscopy of lithium dimer  

NASA Astrophysics Data System (ADS)

We constructed a Ti:Sapphire narrow-band regenerative amplifier as the probe laser of the experiment of momentum imaging spectroscopy of lithium dimer. The spectral profile of the regenerative cavity was designed by three birefringent filters and a plate of etalon. With 1.1-mJ pumping by the second harmonics of Nd:YLF laser, mode-locked seed pulses were amplified to ˜25 ?J at 1-kHz repetition, with the bandwidth of ˜0.7 cm-1.

Matsuoka, Leo; Hashimoto, Masashi; Yokoyama, Keiichi

2012-07-01

408

Energy Delivery Systems for Treatment of Benign Prostatic Hyperplasia  

PubMed Central

Executive Summary Objective The Ontario Health Technology Advisory Committee asked the Medical Advisory Secretariat (MAS) to conduct a health technology assessment on energy delivery systems for the treatment of benign prostatic hyperplasia (BPH). Clinical Need: Target Population and Condition BPH is a noncancerous enlargement of the prostate gland and the most common benign tumour in aging men. (1) It is the most common cause of lower urinary tract symptoms (LUTS) and bladder outlet obstruction (BOO) and is an important cause of diminished quality of life among aging men. (2) The primary goal in the management of BPH for most patients is a subjective improvement in urinary symptoms and quality of life. Until the 1930s, open prostatectomy, though invasive, was the most effective form of surgical treatment for BPH. Today, the benchmark surgical treatment for BPH is transurethral resection of the prostate (TURP), which produces significant changes of all subjective and objective outcome parameters. Complications after TURP include hemorrhage during or after the procedure, which often necessitates blood transfusion; transurethral resection (TUR) syndrome; urinary incontinence; bladder neck stricture; and sexual dysfunction. A retrospective review of 4,031 TURP procedures performed by one surgeon between 1979 and 2003 showed that the incidence of complications was 2.4% for blood transfusion, 0.3% for TUR syndrome, 1.5% for hemostatic procedures, 2.8% for bladder neck contracture, and 1% for urinary stricture. However, the incidence of blood transfusion and TUR syndrome decreased as the surgeon’s skills improved. During the 1990s, a variety of endoscopic techniques using a range of energy sources have been developed as alternative treatments for BPH. These techniques include the use of light amplification by stimulated emission of radiation (laser), radiofrequency, microwave, and ultrasound, to heat prostate tissue and cause coagulation or vaporization. In addition, new electrosurgical techniques that use higher amounts of energy to cut, coagulate, and vaporize prostatic tissue have entered the market as competitors to TURP. The driving force behind these new treatment modalities is the potential of producing good hemostasis, thereby reducing catheterization time and length of hospital stay. Some have the potential to be used in an office environment and performed under local anesthesia. Therefore, these new procedures have the potential to rival TURP if their effectiveness is proven over the long term. The Technology Being Reviewed The following energy-based techniques were considered for assessment: transurethral electrovaporization of the prostate (TUVP) transurethral electrovapor resection of the prostate (TUVRP) transurethral electrovaporization of the prostate using bipolar energy (plasmakinetic vaporization of the prostate [PKVP]) visual laser ablation of the prostate (VLAP) transurethral ultrasound guided laser incision prostatectomy (TULIP) contact laser vaporization of the prostate (CLV) interstitial laser coagulation (ILC) holmium laser resection of the prostate (HoLRP) holmium laser enucleation of the prostate (HoLEP) holmium laser ablation of the prostate (HoLAP) potassium titanyl phosphate (KTP) laser transurethral microwave thermotherapy (TUMT) transurethral needle ablation (TUNA) Review Strategy A search of electronic databases (OVID MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, The Cochrane Library, and the International Agency for Health Technology Assessment [INAHTA] database) was undertaken to identify evidence published from January 1, 2000 to June 21, 2006. The search was limited to English-language articles and human studies. The literature search identified 284 citations, of which 38 randomized controlled trials (RCTs) met the inclusion criteria. Since the application of high-power (80 W) KTP laser (photoselective vaporization of the prostate [PVP]) has been supported in the United States and has resulted in a rapid diffusion of this technology in the absence of any RCTs, th

2006-01-01

409

Field test results of a dry low NOâ combustion system for the MS3002J regenerative cycle gas turbine  

Microsoft Academic Search

A dry low NOâ combustion system for the MS3002J regenerative cycle gas turbine has been developed and successfully installed at two pipeline compressor stations. Preparation for the DLN retrofits began with initial field testing of the conventional system intended to characterize some of the unique features of the two-shaft, regenerative cycle machine that might affect the proposed premixed combustor design.

J. R. Maughan; K. M. Elward; S. M. de Pietro; P. J. Bautista

1997-01-01

410

Determination of the effectiveness and feasibility of regenerative braking systems on electric and other automobiles. Volume I. Summary. Final report  

Microsoft Academic Search

A report is given of a study conducted by Lawrence Livermore Laboratory in which a determination of the effectiveness and feasibility of regenerative braking systems on electric and other automobiles was made. Regenerative braking concepts applicable to autos utilizing electric, hybrid, or heat engine power systems were evaluated to determine performance improvement, energy savings, and cost effectiveness. Two major conclusions

D. D. Davis; R. A. Renner; F. C. Younger; R. C. Epps; S. S. Lerner

1977-01-01

411

Oral intake of hydrogen-rich water inhibits intimal hyperplasia in arterialized vein grafts in rats  

PubMed Central

Aims Arterialized vein grafts often fail due to intimal hyperplasia. Hydrogen potently protects organs and cells from many insults via its anti-inflammatory and antioxidant properties. We investigated the efficacy of oral administration of hydrogen-rich water (HW) for prevention of intimal hyperplasia. Methods and results The inferior vena cava was excised, stored in cold Ringer solution for 2 h, and placed as an interposition graft in the abdominal aorta of syngeneic Lewis rats. HW was generated by immersing a magnesium stick in tap water (Mg + 2H2O ? Mg (OH)2 + H2). Beginning on the day of graft implantation, recipients were given tap water [regular water (RW)], HW or HW that had been subsequently degassed water (DW). Six weeks after grafting, the grafts in the rats given RW or DW had developed intimal hyperplasia, accompanied by increased oxidative injury. HW significantly suppressed intimal hyperplasia. One week after grafting, the grafts in HW-treated rats exhibited improved endothelial integrity with less platelet and white blood cell aggregation. Up-regulation of the mRNAs for intracellular adhesion molecules was attenuated in the vein grafts of the rats receiving HW. Activation of p38 mitogen-activated protein kinase, matrix metalloproteinase (MMP)-2, and MMP-9 was also significantly inhibited in grafts receiving HW. In rat smooth muscle cell (A7r5) cultures, hydrogen treatment for 24 h reduced smooth muscle cell migration. Conclusion Drinking HW significantly reduced neointima formation after vein grafting in rats. Drinking HW may have therapeutic value as a novel therapy for intimal hyperplasia and could easily be incorporated into daily life. PMID:22287575

Sun, Qiang; Kawamura, Tomohiro; Masutani, Kosuke; Peng, Ximei; Sun, Qing; Stolz, Donna B.; Pribis, John P.; Billiar, Timothy R.; Sun, Xuejun; Bermudez, Christian A.; Toyoda, Yoshiya; Nakao, Atsunori

2012-01-01

412

Unitized Regenerative Fuel Cell System Gas Dryer/Humidifier Analytical Model Development  

NASA Technical Reports Server (NTRS)

A lightweight Unitized Regenerative Fuel Cell (URFC) Energy Storage System concept is being developed at the NASA Glenn Research Center (GRC). This Unitized Regenerative Fuel Cell System (URFCS) is unique in that it uses Regenerative Gas Dryers/Humidifiers (RGD/H) that are mounted on the surface of the gas storage tanks that act as the radiators for thermal control of the Unitized Regenerative Fuel Cell System (URFCS). As the gas storage tanks cool down during URFCS charging the RGD/H dry the hydrogen and oxygen gases produced by electrolysis. As the gas storage tanks heat up during URFCS discharging, the RGD/H humidify the hydrogen and oxygen gases used by the fuel cell. An analytical model was developed to simulate the URFCS RGD/H. The model is in the form of a Microsoft (registered trademark of Microsoft Corporation) Excel worksheet that allows the investigation of the RGD/H performance. Finite Element Analysis (FEA) modeling of the RGD/H and the gas storage tank wall was also done to analyze spatial temperature distribution within the RGD/H and the localized tank wall. Test results obtained from the testing of the RGD/H in a thermal vacuum environment were used to corroborate the analyses.

Burke, Kenneth A.; Jakupca, Ian

2004-01-01

413

A Series Regenerative Braking Control Strategy Based on Hybrid-Power  

Microsoft Academic Search

A regenerative braking system, which could restore kinetic energy and potential energy to a battery or any other forms of power during braking, is a special system for electric and hybrid electric vehicles. However, the large current produced by the generator during braking would affect battery performance and shorten battery life. A hybrid-power system is an excellent energy storage system,

Feng Wang; Xiaomei Yin; Huangqiang Luo; Ying Huang

2012-01-01

414

Name: dhr. prof. dr. W.J.A Dhert Regenerative Medicine  

E-print Network

Name: dhr. prof. dr. W.J.A Dhert Profile Teaching commitment Regenerative Medicine Faculty Medicine, Creemers LB, van Rijen MH, Verbout AJ, Saris DB, Dhert WJ. Cartilage damage caused by metal implants Medicine', as part of the UU Graduate School of Life Sciences Additional activities · Member editorial

Utrecht, Universiteit

415

Broadband Yb:CaF2 regenerative amplifier for millijoule range ultrashort pulse amplification  

E-print Network

Broadband Yb:CaF2 regenerative amplifier for millijoule range ultrashort pulse amplification line at 978 nm with a 10W continuous wave (CW) fiber coupled laser diode. The pulses have a spectral quenching and gives rise to high efficiencies even at high pump power. For some specific applications, sub

Paris-Sud XI, Université de

416

ENSC 461 PROJECT: Development of a new hydraulic regenerative energy storage system  

E-print Network

and trucks. While electric hybrid vehicles regenerative efficiency is less than 40%, prototype hydraulic Electricity input To user Power conditioning unit Flow meter T P TP System parameters: Temp, Press electrical energy after production is a challenge. Integrating electricity storage into the electrical

Bahrami, Majid

417

Value-Engineered Translation for Regenerative Medicine: Meeting the Needs of Health Systems  

PubMed Central

Abstract Despite high expectations of economic returns, large investments in regenerative medicine technology have yet to materialize, partly due to a lack of proven business and investment models, regulatory hurdles, and a greater focus on cost-effectiveness for reimbursement decisions by payors. Adoption of new economic modeling methods will better link investment decisions to value-based criteria of health systems. PMID:24304083

Bubela, Tania; McCabe, Christopher

2013-01-01

418

Regenerative patterning in Swarm Robots: mutual benefits of research in robotics and stem cell biology  

E-print Network

-healing and self-regeneration. We first discuss the essential features of biological stem cells for such a purposeRegenerative patterning in Swarm Robots: mutual benefits of research in robotics and stem cell California, CA, USA ABSTRACT This paper presents a novel perspective of Robotic Stem Cells (RSCs), defined

Shen, Wei-Min

419

The potential role of regenerative medicine in the man-agement of traumatic patients.  

PubMed

Traumatic injury represents the most common cause of death in ages 1 to 44 years and asignificant proportion of patients treated in hospital emergency wards each year. Unfortunately, for patients who survive their injuries, survival is not equal to complete recovery. Many traumatic injuries are difficult to treat with conventional therapy and result in permanent disability. In such situations, regenerative medicine has the potential to play an important role in recovery of function. Regenerative medicine is a field that seeks to maintain or restore function with the development of biological substitutes for diseased or damaged tissues. Several regenerative approaches are currently under investigation, with a few achieving clinical application. For example, engineered skin has gained FDA approval, and more than 20 tissue engineered skin substitutes are now commercially available. Other organ systems with promising animal models and small human series include the central and peripheral nervous systems, the musculoskeletal system, the respiratory and genitourinary tracts, and others. This paper will be a clinically oriented review of the regenerative approaches currently under investigation of special interest to those caring for traumatic patients. © 2015 KUMS, All rights reserved. PMID:25618439

Moradi, Mahmoudreza; Hood, Brandy; Moradi, Marzieh; Atala, Anthony

2015-01-01

420

Characterization of microbial species in a regenerative bio-filter system for volatile organic compound removal  

Microsoft Academic Search

Effective removal of volatile organic compounds is critical for indoor air quality control. The performance of traditional technologies of volatile organic compound removal is limited by inadequate selection of filter media, poor airflow management inside the cleaning devices, insufficient catalytic reaction surface area, and poor distribution of UV light irradiation. In comparison, the relatively new regenerative air filtration systems use

Wen-Hsuan Huang; Zhiqiang Wang; Geetika Choudhary; Beverly Guo; Jianshun Zhang; Dacheng Ren

2012-01-01

421

Modeling of the Regenerative Heat Flow of the Wall in Direct Fired Rotary Kilns  

Microsoft Academic Search

An analytical one-dimensional model was developed to predict the effect of the different kiln variables on the regenerative heat transfer by the wall in a rotary kiln. The basis of this model is introducing a lumped capacity layer with infinite conductivity in radial direction. The thickness of this layer is determined from the heat penetration in a semi-infinite body. The

Sri Silvia Agustini; Andreas Queck; Eckehard Specht

2008-01-01

422

Polymers for tissue engineering, medical devices, and regenerative medicine. Concise general review of recent studies  

Microsoft Academic Search

Recently investigated applications of polymeric materials for tissue engineering, regenerative medicine, implants, stents, and medical devices are described in the present review. Papers published during the last 2 years about polymeric materials used for preparation of various polymeric scaffolds, methods of fabrication of such scaffolds and their effectiveness in providing support for cell growth and development into various tissues and

Joseph Jagur-Grodzinski

2006-01-01

423

Pitting corrosion control using regenerative biolms on aluminium 2024 in articial seawater  

E-print Network

Pitting corrosion control using regenerative bio®lms on aluminium 2024 in arti®cial seawater D, CT 06269-3222, USA b Corrosion and Environment Eects Laboratory (CEEL), Department of Materials polyglutamate or polyaspartate, an additional small increase in corrosion inhibition occurred. Corrosion control

Wood, Thomas K.

424

Corrosion Control Using Regenerative Biofilms on Aluminum 2024 and Brass in Different Media  

E-print Network

Corrosion Control Using Regenerative Biofilms on Aluminum 2024 and Brass in Different Media F. Mansfeld,a, *,z H. Hsu,a D. O¨ rnek,b T. K. Wood,b and B. C. Syrettc a Corrosion and Environmental Effects Institute, Palo Alto, California 94303, USA The corrosion behavior of Al 2024-T3 and C26000 brass exposed

Wood, Thomas K.

425

Corrosion control using regenerative biofilms (CCURB) on brass in different media  

E-print Network

Corrosion control using regenerative biofilms (CCURB) on brass in different media D. OOrnek a , T of Chemical Engineering, University of Connecticut, Storrs, CT 06269-3222, USA b Corrosion and Environmental The corrosion behavior of cartridge brass (UNS C26000) exposed to artificial seawater (AS) and Luria Bertani (LB

Wood, Thomas K.

426

Neural Network Self-adaptive PID Control for Driving and Regenerative Braking of Electric Vehicle  

Microsoft Academic Search

In order to deal with the main problems of electric vehicle (EV), such as the short driving range, the short life of batteries, the variation of the road state and driving mode and so on, based on constructing the main circuit diagram of the EV's control system and researching driving and regenerative braking process, the mathematical model of the system

Jianbo Cao; Binggang Cao; Wenzhi Chen; Peng Xu

2007-01-01

427

Performance study of a regenerative flow compressor as a secondary air pump for engine emission control  

NASA Astrophysics Data System (ADS)

This thesis reviews the status of regenerative flow pumps and compressors (RFP/RFC) for fuel emission reduction, and proposes design guidelines with the aim to improve their flow and efficiency. A brief overview of the fundamentals and hypothesis of the operation of RFP/RFC is presented. An analytical model for regenerative flow pumps and compressors is developed, and a one-dimensional (1-D) performance prediction code of an RFP/RFC model is synthesized using geometric parameters as input. Based on these predictions, design guidelines to improve performance of these turbomachines are proposed. CFD analysis is undertaken to validate these proposed design changes. Prototypes of current and proposed design changes of regenerative flow pumps and compressors are built and tested, and experimental data is studied and compared to the theoretical and numerical simulation findings. Sensitivity analysis is conducted on various design parameters to study their effect on the device's performance, and designs for optimum performance were created. The design approach is generalized and applied to a larger family of RFP pumps and compressors. A streamlined approach to RFC/RFP improvement is developed for future applications and more efficient regenerative flow pumps, which are the result of this study, are built, tested, and used in current applications for emission reduction and control in passenger and industrial vehicles.

Elkacimi, Younes

428

The potential role of regenerative medicine in the management of traumatic patients  

PubMed Central

Abstract: Traumatic injury represents the most common cause of death in ages 1 to 44 years and a significant proportion of patients treated in hospital emergency wards each year. Unfortunately, for patients who survive their injuries, survival is not equal to complete recovery. Many traumatic injuries are difficult to treat with conventional therapy and result in permanent disability. In such situations, regenerative medicine has the potential to play an important role in recovery of function. Regenerative medicine is a field that seeks to maintain or restore function with the development of biological substitutes for diseased or damaged tissues. Several regenerative approaches are currently under investigation, with a few achieving clinical application. For example, engineered skin has gained FDA approval, and more than 20 tissue engineered skin substitutes are now commercially available. Other organ systems with promising animal models and small human series include the central and peripheral nervous systems, the musculoskeletal system, the respiratory and genitourinary tracts, and others. This paper will be a clinically oriented review of the regenerative approaches currently under investigation of special interest to those caring for traumatic patients. PMID:25618439

Moradi, Mahmoudreza; Hood, Brandy; Moradi, Marzieh; Atala, Anthony

2015-01-01

429

Regenerative Hair Waves in Aging Mice and Extra-Follicular Modulators Follistatin, Dkk1,  

E-print Network

Regenerative Hair Waves in Aging Mice and Extra-Follicular Modulators Follistatin, Dkk1, and Sfrp4 , Oscar K. Lee2,6 , Randall B. Widelitz1 and Cheng-Ming Chuong1,2 Hair cycling is modulated by factors both intrinsic and extrinsic to hair follicles. Cycling defects lead to conditions such as aging

Chuong, Cheng-Ming

430

NUCLEIC ACID DETECTION USING BIOLUMINESCENCE REGENERATIVE CYCLE AND STATISTICAL SIGNAL PROCESSING  

E-print Network

NUCLEIC ACID DETECTION USING BIOLUMINESCENCE REGENERATIVE CYCLE AND STATISTICAL SIGNAL PROCESSING H- velopment of signal processing techniques for rapid real- time nucleic acid detection [1]. In this paper, we experimental results. 1. ON NUCLEIC ACID DETECTION The identification and quantification of nucleic acid

Hassibi, Arjang

431

Educational tool for modeling and simulation of a closed regenerative life support system  

NASA Astrophysics Data System (ADS)

For long term missions on the moon and Mars, regenerative life support systems emerge as a promising key technology for sustaining successful explorations with reduced re-supply logistics and cost. The purpose of this study was to create a simple model of a regenerative life support system which allows preliminary investigation of system responses. A simplified regenerative life support system was made with MATLAB Simulink ™. Mass flows in the system were simplified to carbon, water, oxygen and carbon dioxide. The subsystems included crew members, animals, a plant module, and a waste processor, which exchanged mass into and out of mass reservoirs. Preliminary numerical simulations were carried out to observe system responses. The simplified life support system model allowed preliminary investigation of the system response to perturbations such as increased or decreased number of crew members. The model is simple and flexible enough to add new components, and also possible to numerically predict non-linear subsystem functions and responses. Future work includes practical issues such as energy efficiency, air leakage, nutrition, and plant growth modeling. The model functions as an effective teaching tool about how a regenerative advanced life support system works.

Arai, Tatsuya; Fanchiang, Christine; Aoki, Hirofumi; Newman, Dava J.

432

Stem Cells in Drug Discovery, Tissue Engineering, and Regenerative Medicine: Emerging Opportunities and Challenges  

Microsoft Academic Search

Stem cells, irrespective of their origin, have emerged as valuable reagents or tools in human health in the past 2 decades. Initially, a research tool to study fundamental aspects of developmental biology is now the central focus of generating transgenic animals, drug discovery, and regenerative medicine to address degenerative diseases of multiple organ systems. This is because stem cells are

Victor Sanjit Nirmalanandhan; G. Sitta Sittampalam

2009-01-01

433

Fast Threat Detection and Localization Using Super-Regenerative Transceiver in  

E-print Network

Fast Threat Detection and Localization Using Super-Regenerative Transceiver in Random Noise Radar system, which applies simple monopulse-type processing on transient target signatures to extract measurement results are presented for SRG transceiver and monopulse processing implementations. Index Terms

Zhang, Yan

434

TV picture-tube manufacturer uses regenerative catalytic oxidizer to reduce VOC emissions  

SciTech Connect

Toshiba Display Services, a television picture-tube manufacturer in Horseheads, NY, recently was able to meet stringent state regulations to reduce emissions from two of its film applications lines by installing a regenerative catalytic oxidation system. Toshiba officials initially evaluated several technologies to control volatile organic compounds. After deciding that oxidation was the best technology for its facility, the company invited a number of suppliers to submit proposals. Because all of the oxidation technologies considered by Toshiba had the capability to achieve the destruction and removal efficiency requirement, the company combined the second and third decision elements and conducted an in-depth comparison of the initial capital and ongoing operating costs for each proposal. Officials narrowed the field to two systems--the lowest-cost regenerative thermal oxidation system on the market and a regenerative catalytic oxidation system. The company selected St. Louis, Mo.-based Monsanto Enviro-Chem Systems Inc., to install its DynaCycle{reg_sign} regenerative catalytic oxidation system, marking the first Dyna-Cycle installation in a US television picture-tube facility.

NONE

1995-11-01

435

Genetic variation in bone-regenerative capacity among inbred strains of mice.  

PubMed

Genetic variation in bone-regenerative capacity has not been studied in any animal model system. We developed a "drill-hole" model in the tail vertebra of inbred strains of mice that allows us to reproducibly introduce an injury with a defined boundary and quantify the rate of bone healing using the combination of high-resolution Faxitron X-ray imaging and the ChemiImager 4000 Low Light Imaging System. Using this model, we demonstrate that bone-regenerative capacity is a genetically controlled trait with an estimated heritability of 72%, and that it differs significantly among inbred strains of mice. Of the 12 inbred strains tested, Sencar/PtJ was identified as the most suitable model for the study of hard-tissue regeneration. This strain regained 73% of bone loss 30 days after injury, in contrast to the slow healer, CBA/J, which recovered only 25% of the bone loss during the same period. Bone-regenerative capacity was not correlated with soft-tissue-regenerative capacity, suggesting that different sets of genes may regulate soft- and hard-tissue regeneration. It was, however, significantly correlated with total bone mineral density (R = 0.49, p < 0.01), indicating that high bone density is associated not only with prevention of bone fracture, but also with promotion of bone regeneration. PMID:11502474

Li, X; Gu, W; Masinde, G; Hamilton-Ulland, M; Rundle, C H; Mohan, S; Baylink, D J

2001-08-01

436

Experimental research on cutting force variation during regenerative chatter vibration in a plain milling operation  

Microsoft Academic Search

A plain milling operation is characterized by a transient and intermittent cutting process, in which undeformed chip thickness varies continuously. The reverse is the case in variations of undeformed chip thickness in the processes of up- and down-milling. In the present study, the property of regenerative chatter vibration in a plain milling operation is investigated from the viewpoint of cutting

M. Hashimoto; E. Marui; S. Kato

1996-01-01

437

The application of Fuzzy Delphi Method and Fuzzy AHP in lubricant regenerative technology selection  

Microsoft Academic Search

Due to the funding scale and complexity of lubricant regenerative technology, the selection of recycling technology and policy for waste lubricant oil can be viewed as a multiple-attribute decision process that is normally made by a review committee with experts from academia, industry, and the government. This study aims to provide a systematic approach towards the technology selection, in which

Yu-lung Hsu; Cheng-haw Lee; Victor B. Kreng

2010-01-01

438

Computer modeling of a regenerative solar-assisted Rankine power cycle  

Microsoft Academic Search

A detailed interpretation of the computer program that describes the performance of one of these cycles; namely, a regenerative Rankine power cycle is presented. Water is used as the working medium throughout the cycle. The solar energy collected at relatively low temperature level presents 75 to 80% of the total heat demand and provides mainly the latent heat of vaporization.

F. L. Lansing

1977-01-01

439

of Stem Cell Biology and Regenerative Medicine Forum" DateNov 27th  

E-print Network

serves as a suitable donor source in hematopoietic stem cell transplantation. However, the time"The 75th of Stem Cell Biology and Regenerative Medicine Forum" DateNov 27th (Thu) 2014 Time : 18 ------------------------------------------------------------------------------------------------------------------------------------ Internal Speaker 18:00-18:30 Takashi IshidaDivision of Stem Cell Therapy, Center for Stem Cell Biology

Miyashita, Yasushi

440

Diode-pumped Nd:glass kilohertz regenerative amplifier for subpicosecond microjoule level pulses  

E-print Network

-power laser-diode tech- nology, direct laser-diode pumping of solid-state ma- terial is allowing diode pumping may replace argon­ion, krypton-ion, and Q-switched solid-state pump lasers for both modeDiode-pumped Nd:glass kilohertz regenerative amplifier for subpicosecond microjoule level pulses

Keller, Ursula

441

Modelling ultrasound-induced mild hyperthermia of hyperplasia in vascular grafts  

PubMed Central

Background Expanded polytetrafluoroethylene (ePTFE) vascular grafts frequently develop occlusive neointimal hyperplasia as a result of myofibroblast over-growth, leading to graft failure. ePTFE exhibits higher ultrasound attenuation than native soft tissues. We modelled the selective absorption of ultrasound by ePTFE, and explored the feasibility of preventing hyperplasia in ePTFE grafts by ultrasound heating. Specifically, we simulated the temperature profiles of implanted grafts and nearby soft tissues and blood under ultrasound exposure. The goal was to determine whether ultrasound exposure of an ePTFE graft can generate temperatures sufficient to prevent cell growth on the graft without damaging nearby soft tissues and blood. Methods Ultrasound beams from two transducers (1.5 and 3.2 MHz) were simulated in two graft/tissue models, with and without an intra-graft cellular layer mimicking hyperplasia, using the finite-difference time-domain (FDTD) method. The resulting power deposition patterns were used as a heat source for the Pennes bioheat equation in a COMSOL® Multiphysics heat transfer model. 50°C is known to cause cell death and therefore the transducer powers were adjusted to produce a 13°C temperature rise from 37°C in the ePTFE. Results Simulations showed that both the frequency of the transducers and the presence of hyperplasia significantly affect the power deposition patterns and subsequent temperature profiles on the grafts and nearby tissues. While neither transducer significantly raised the temperature of the blood, the 1.5-MHz transducer was less focused and heated larger volumes of the graft and nearby soft tissues than the 3.2-MHz transducer. The presence of hyperplasia had little effect on the blood's temperature, but further increased the temperature of the graft and nearby soft tissues in response to either transducer. Skin cooling and blood flow play a significant role in preventing overheating of the native tissues. Conclusions Modelling shows that ultrasound can selectively heat ePTFE grafts and produce temperatures that cause cell death on the graft. The temperature increase in blood is negligible and that in the adjacent soft tissues may be minimized by skin cooling and using appropriate transducers. Therefore, ultrasound heating may have the potential to reduce neointimal hyperplasia and failure of ePTFE vascular grafts. PMID:22054016

2011-01-01

442

Successful treatment for adrenocorticotropic hormone-independent macronodular adrenal hyperplasia with laparoscopic adrenalectomy: a case series  

PubMed Central

Introduction Adrenocorticotropic hormone-independent macronodular adrenal hyperplasia, characterized by bilateral macronodular adrenal hypertrophy and autonomous cortisol production, is a rare cause of Cushing’s syndrome. Bilateral adrenalectomy is considered the standard treatment for adrenocorticotropic hormone-independent macronodular adrenal hyperplasia but obliges the patient to receive lifetime steroid replacement therapy subsequently, and may increase the patient’s risk of adrenal insufficiency. These circumstances require surgeons to carefully consider operative strategies on an individual basis. Case presentation We performed successful laparoscopic adrenalectomy on four patients with adrenocorticotropic hormone-independent macronodular adrenal hyperplasia. Computed tomography scans showed bilateral adrenal enlargement in all patients. Case 1: a 56-year-old Japanese woman presented with obvious Cushing’s symptoms during treatment for diabetes mellitus and hypertension. Case 2: a 37-year-old Japanese man also presented with Cushing’s symptoms during treatment for diabetes mellitus and hypertension. These patients were diagnosed as Cushing’s syndrome caused by adrenocorticotropic hormone-independent macronodular adrenal hyperplasia based on endocrinologic testing, and underwent bilateral laparoscopic adrenalectomy. Case 3: an 80-year-old Japanese woman was hospitalized due to unusual weight gain and heightened general fatigue, and was diagnosed as Cushing’s syndrome caused by adrenocorticotropic hormone-independent macronodular adrenal hyperplasia. She underwent unilateral laparoscopic adrenalectomy due to high operative risk. Case 4: a 66-year-old Japanese man was discovered to have bilateral adrenal tumors on medical examination. He did not have Cushing’s symptoms and was diagnosed as subclinical Cushing’s syndrome due to suppressed adrenocorticotropic hormone serum levels and loss of cortisol circadian rhythm without abnormal levels of serum cortisol. He underwent unilateral laparoscopic adrenalectomy. During follow-up, serum cortisol levels were within the normal range in all cases, and serum adrenocorticotropic hormone levels were not suppressed. Further, cases with Cushing’s syndrome experienced clinical improvement. Conclusions We were able to effectively treat adrenocorticotropic hormone-independent macronodular adrenal hyperplasia in patients with obvious Cushing’s symptoms by laparoscopic bilateral adrenalectomy, which promptly improved symptoms. Further, unilateral adrenalectomy was effective for treating an older patient at high operative risk and a patient with subclinical Cushing’s syndrome. PMID:22989371

2012-01-01

443

Nitric oxide may inhibit neointimal hyperplasia by decreasing isopeptidase T levels and activity in the vasculature  

PubMed Central

Objective Isopeptidase T is a cysteine protease deubiquitinating enzyme that hydrolyzes unanchored polyubiquitin chains to free monoubiquitin. Nitric oxide (NO) decreases 26S proteasome activity in vascular smooth muscle cells (VSMCs) and inhibits neointimal hyperplasia in animal models. As NO can cause S-nitrosylation of active-site cysteines, we hypothesize that NO inhibits isopeptidase T activity through S-nitrosylation. Because accumulation of polyubiquitin chains inhibits the 26S proteasome, this may be one mechanism through which NO prevents neointimal hyperplasia. Methods To investigate our hypothesis, we examined the effect of NO on isopeptidase T activity, levels, and localization in VSMCs in vitro and in a rat carotid balloon injury model in vivo. Results NO inhibited recombinant isopeptidase T activity by 82.8% (t = 60 minutes, P < .001 vs control). Dithiothreitol and glutathione (5 mmol/L) both significantly reversed NO-mediated inhibition of isopeptidase T activity (P < .001). NO caused a time-dependent increase in S-nitrosylated isopeptidase T levels in VSMCs, which was reversible with dithiothreitol, indicating that isopeptidase T undergoes reversible S-nitrosylation on exposure to NO in vitro. Although NO did not affect isopeptidase T levels or subcellular localization in VSMCs in vitro, it decreased isopeptidase T levels and increased ubiquitinated proteins after balloon injury in vivo. Conclusions Local administration of NO may prevent neointimal hyperplasia by inhibiting isopeptidase T levels and activity in the vasculature, thereby inhibiting the 26S proteasome in VSMCs. These data provide additional mechanistic insights into the ability of NO to prevent neointimal hyperplasia after vascular interventions. (J Vasc Surg 2013;?:1-8.) Clinical Relevance The 26S proteasome is responsible for degrading polyubiquitinated proteins. Isopeptidase T is a deubiquitinating enzyme that recycles polyubiquitin chains to monoubiquitin. Nitric oxide (NO) decreases formation of neointimal hyperplasia in animal models and decreases 26S proteasome activity in vascular smooth muscle cells. We investigated the effects of NO on isopeptidase T and showed that NO inhibits recombinant isopeptidase T activity, increases S-nitrosylated isopeptidase T levels in vascular smooth muscle cells, and, after balloon injury in vivo, decreases isopeptidase T levels and increases ubiquitinated proteins. Local administration of NO may prevent neointimal hyperplasia by targeting isopeptidase T and inhibiting the 26S proteasome. PMID:23375434

Tsihlis, Nick D.; Kapadia, Muneera R.; Vavra, Ashley K.; Flannery, Walker D.; Oustwani, Christopher S.; Jiang, Qun; Kibbe, Melina R.

2013-01-01