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1

Detection of anaerobic odontogenic infections by fluorine-18 fluoromisonidazole  

Microsoft Academic Search

Odontogenic infections are a potential risk for patients who receive cervicofacial radiotherapy and should be treated before irradiation. Anaerobic microbial infections are the most common causes. This study assessed the value of the hypoxic imaging agent fluorine-18 fluoromisonidazole (FMISO) in detecting anaerobic odontogenic infections. Positron emission tomography (PET) imaging was performed at 2 h after injection of 370 MBq (10

Ren-Shyan Liu; Lee-Shing Chu; San-Hui Yen; Chen-Pei Chang; Kuo-Liang Chou; Liang-Chi Wu; Chi-Wei Chang; Mun-Tain Lui; Kuang Y Chenl; Shin-Hwa Yeh

1996-01-01

2

Bacteriologic features and antimicrobial susceptibility in isolates from orofacial odontogenic infections  

Microsoft Academic Search

Objective: The aim of this study was to obtain information for an effective antimicrobial therapy against orofacial odontogenic infections; such information was obtained from recent bacteriologic features and antimicrobial susceptibility data. Study Design: The bacteriology and antimicrobial susceptibility of major pathogens in 163 patients with orofacial odontogenic infections to 7 antibiotics was examined. Results: Mixed infection of strict anaerobes with

Tomoari Kuriyama; Tadahiro Karasawa; Kiyomasa Nakagawa; Yasumasa Saiki; Etsuhide Yamamoto; Shinichi Nakamura

2000-01-01

3

Brain abscess potentially secondary to odontogenic infection: case report.  

PubMed

Odontogenic infections are rarely implicated in the causes of brain abscess formation. As such, there are very few reports of brain abscesses secondary to odontogenic infections in the literature. This is due partly to the relative rarity of brain abscesses but also to the difficulty in matching the causative organisms of a brain abscess to an odontogenic source. The authors report a case of a 50-year-old woman whose brain abscess may potentially have been secondary to an odontogenic infection. The patient's early diagnosis, supported by imaging and microbiologic assessment, along with early minicraniotomy and extraction of infected dentition followed by a course of cephalosporins and metronidazole, contributed to a successful outcome. PMID:24157081

Yang, Joseph; Liu, Stanley Y; Hossaini-Zadeh, Mehran; Pogrel, M Anthony

2014-02-01

4

Infected orthokeratinized odontogenic cyst: a rare cause of facial cellulitis.  

PubMed

Orthokeratinized odontogenic cysts (OOCs) are relatively uncommon developmental cysts lined with orthokeratinized epithelium consisting of a prominent granular layer and a basal layer of low cuboidal flattened cells that show no tendency for nuclear palisading. These cysts have been considered a distinct entity from odontogenic keratocysts since they exhibit a less aggressive behavior and a very low rate of recurrence. Developmental odontogenic cysts can become infected but serious complications, such as potentially life-threatening cellulitis, are rare. This report describes a rare case of facial cellulitis secondary to an infected OOC located in the mandible of a 27-year-old man. The relevant literature about the clinical-pathological features of OOC is reviewed. PMID:23306244

Carvalho, Cyntia Helena Pereira de; Aquino, Ana Rafaela Luz de; Nonaka, Cassiano Francisco Weege; Silva, José Sandro Pereira da; Germano, Adriano da Rocha; Pinto, Leão Pereira

2012-01-01

5

Brain abscess due to odontogenic infection: a case report  

PubMed Central

In this report, we describe a case of brain abscess due to odontogenic infection. A 53-year-old female who had been suffering from headache and trismus for two weeks visited the Department of Oral and Maxillofacial Surgery at the Sun Dental Hospital (Daejeon, Korea). Even after several routine tests, we still could not make a diagnosis. However, after the combined multidisciplinary efforts of oral surgeons and neurosurgeons, the patient was treated for odontogenic infection and made an uneventful recovery. Therefore, patients with infections in the head and neck region showing symptoms such as headache, changes in mental state, nausea, vomiting, seizures, hemiplegia, speech disturbance, and visual disturbance, a brain abscess should be included in the list of differential diagnoses. PMID:25045643

Park, Sung Yong; Suh, Dong Won; Park, Chul Min; Oh, Min Seok

2014-01-01

6

Descending necrotizing mediastinitis due to odontogenic infections  

Microsoft Academic Search

Objective. Acute purulent mediastinitis caused by oropharyngeal infection is termed descending necrotizing mediastinitis . Such infections usually have a fulminate course, leading to sepsis and frequently to death. The purpose of this study is to show the importance of early diagnosis, aggressive surgical intervention, and optimal antibiotics chemotherapy in controlling this fatal infectious disease. Study design. Two patients with descending

Haruo Sakamoto; Takayuki Aoki; Yoshifumi Kise; Daisuke Watanabe; Jiro Sasaki

2000-01-01

7

Odontogenic deep neck space infection as life-threatening condition in pregnancy.  

PubMed

Odontogenic deep neck space infections represent a severe disease with possible life-threatening complications. Despite knowledge of these infectious diseases, treatment remains a challenge for every maxillofacial surgeon. Therapy of severe neck infections is even more crucial during pregnancy because of the possible life-threatening situation for both the mother and the foetus. The possible compromise of oral health during pregnancy is well known, however severe odontogenic infections are rarely considered in the literature. The following case report describes the dramatic course of a deep neck space infection in a pregnant patient, commencing with typical symptoms of localized odontogenic infection and ending in a critical, life-threatening condition for the patient and a lethal condition for the foetus. The case represents the first description of intrauterine, foetal death caused by a deep neck space infection. Implications for dental and medical treatment during pregnancy, especially regarding odontogenic infections, are presented and discussed with findings in the international literature. PMID:24819888

Dalla Torre, D; Burtscher, D; Höfer, D; Kloss, F R

2014-09-01

8

Anaerobic bacteria in 118 patients with deep-space head and neck infections from the University Hospital of Maxillofacial Surgery, Sofia, Bulgaria  

Microsoft Academic Search

The aim of this study was to assess the incidence and susceptibility to antibacterial agents of anaerobic strains in 118 patients with head and neck abscesses (31) and cellulitis (87). Odontogenic infection was the most common identified source, occurring in 73 (77?7%) of 94 patients. The incidence of anaerobes in abscesses and cellulitis was 71 and 75?9%, respectively, and that

Lyudmila Boyanova; Rossen Kolarov; Galina Gergova; Elitsa Deliverska; Jivko Madjarov; Milen Marinov; Ivan Mitov

2006-01-01

9

Anaerobic Infections in Children with Neurological Impairments.  

ERIC Educational Resources Information Center

Children with neurological impairments are prone to develop serious infection with anaerobic bacteria. The most common anaerobic infections are decubitus ulcers; gastrostomy site wound infections; pulmonary infections (aspiration pneumonia, lung abscesses, and tracheitis); and chronic suppurative otitis media. The unique microbiology of each of…

Brook, Itzhak

1995-01-01

10

Orbital abscess as a complication of odontogenic infection. A case report and review of the literature.  

PubMed

Orbital abscess is a rare complication of odontogenic infection. This report describes a case of an orbital abscess in a 42-year-old HIV-seropositive woman who developed this condition as a complication by direct spread via the maxillary sinus of a dento-alveolar abscess of the maxillary first premolar, resulting in the loss of her eye. PMID:18019813

Masipa, J N; Bouckaert, M; Masureik, C; Lemmer, J; Meyerov, R; Feller, L

2007-08-01

11

Genotypic Diversity of Anaerobic Isolates from Bloodstream Infections  

Microsoft Academic Search

Accurate species determination for anaerobes from blood culture bottles has become increasingly important with the reemergence of anaerobic bacteremia and prevalence of multiple-drug-resistant microorganisms. Our knowl- edge of the taxonomical diversity of anaerobes that cause bloodstream infections is extremely limited, because identification historically has relied on conventional methods. Over a 5-year period, we profiled anaerobic bacte- remia at a large

Keith E. Simmon; L. Barth Reller; Cathy A. Petti

2008-01-01

12

Pattern of Odontogenic Infections at a Tertiary Hospital in Tehran, Iran: A 10-Year Retrospective Study of 310 Patients  

PubMed Central

Objective: To retrospectively evaluate the treated cases with odontogenic abscess and identify the outcome of odontogenic infections, their characteristics and treatment modalities. Materials and Methods: This retrospective study was performed by collecting data from 310 patient records at the oral and maxillofacial surgery department of Taleghani hospital, Tehran, Iran from January 2001 to January 2011. The variables were age, gender, affected teeth, affected facial spaces, type of bacterial source, type of antibiotic therapy, previous medication, hospital stay, body temperature on admission and past medical history. Results: The patients’ ages were between 2 and 84 years and 62.6% of the patients with odontogenic infection were younger than 35 years old. Most of the patients had a body temperature of 37–37.5°C. The most involved teeth were mandibular third molar. Deciduous teeth contained 6.4% of the involved teeth, among which mandibular molars were the most involved. 24.3% of the patients were hospitalized for 4 days. Streptococci were the most detected bacterial strain. The most involved anatomic space was the buccal space and 22.5% of the cases had multi space involvement and 17 cases had Ludwig’s angina. The most common used antibiotic regimens were penicillin G and metronidazole or cefazolin and metronidazole. The mortality rate was 1%, all of whom had Ludwig’s angina. Conclusion: The main affected facial spaces were buccal and submandibular spaces. The most common used antibiotic was penicillin, proving its effectiveness in the treatment of jaw infections. Odontogenic abscesses are mostly related to the eruption of mandibular molars. PMID:24396351

Pourdanesh, Fereydoun; Dehghani, Nima; Azarsina, Mohadese; Malekhosein, Zahra

2013-01-01

13

Nitroimidazoles: in vitro activity and efficacy in anaerobic infections.  

PubMed

Nitroimidazoles, including metronidazole, tinidazole and ornidazole, are low molecular weight antimicrobial compounds with excellent activity against anaerobic microorganisms. These compounds are usually bactericidal at low concentrations and their spectrum of activity encompasses almost all the anaerobic bacteria and some capnophylic organisms. The few anaerobic bacteria known to be resistant to the nitroimidazoles include occasional anaerobic cocci, some nonsporing gram positive bacilli and Propionibacterium. Nitroimidazoles are the most active antimicrobial agents known against Bacteroides fragilis, the most resistant of anaerobic bacteria. Kill-curve studies demonstrate that there is a 2 to 5 log decrease in the number of colony forming units with Bacteroides fragilis and clostridium perfringens within one hour. The killing is unaffected by inoculum, growth rate or components of the medium. However, a metronidazole resistant isolate of B. fragilis has been shown to have decreased ability to take up 14C-metronidazole as well as lessened ability to reduce metronidazole. This is associated with a decrease in the nitroreductase activity. The in vitro observations have also been demonstrated in vivo. Clinical studies have shown nitroimidazoles to be efficacious in the therapy of a variety of anaerobic infections including non-traumatic brain abscess, intraabdominal abscesses, pelvic suppuration and necrotizing soft tissue infections. However, there have been disappointing results in the therapy of anaerobic pleuropulmonary infections, with a number of superinfections caused by aerobic bacteria. PMID:6941456

Tally, F P; Goldin, B; Sullivan, N E

1981-01-01

14

Aerobic and anaerobic microbiology of infections after trauma in children.  

PubMed Central

OBJECTIVE: To review the recovery of aerobic and anaerobic bacteria from infections after trauma in children over a 20 year period. METHODS: Only specimens that were studied for both aerobic and anaerobic bacteria were included in the analysis. They were collected from seven separate centres in which the microbiology laboratories only accepted specimens that were properly collected without contamination and were submitted in appropriate transport media. Anaerobes and aerobic bacteria were cultured and identified using standard techniques. Clinical records were reviewed to identify post-trauma patients. RESULTS: From 1974 to 1994, 175 specimens obtained from 166 children with trauma showed bacterial growth. The trauma included blunt trauma (71), lacerations (48), bites (42), and open fractures (5). Anaerobic bacteria only were isolated in 38 specimens (22%), aerobic bacteria only in 51 (29%), and mixed aerobic-anaerobic flora in 86 (49%); 363 anaerobic (2.1/specimen) and 158 aerobic or facultative isolates (0.9/specimen) were recovered. The predominant anaerobic bacteria included Peptostreptococcus spp (115 isolates), Prevotella spp (68), Fusobacterium spp (52), B fragilis group (42), and Clostridium spp (21). The predominant aerobic bacteria included Staph aureus (51), E coli (13), Ps aeruginosa (12), Str pyogenes (11) and Klebsiella pneumoniae (9). Principal infections were: abscesses (52), bacteraemia (3), pulmonary infections (30, including aspiration pneumonia, tracheostomy associated pneumonia, empyema, and ventilator associated pneumonia), wounds (36, including cellulitis, post-traumatic wounds, decubitus ulcers, myositis, gastrostomy and tracheostomy site wounds, and fasciitis), bites (42, including 23 animal and 19 human), peritonitis (4), osteomyelitis (5), and sinusitis (3). Staph aureus and Str pyogenes were isolated at all sites. However, organisms of the oropharyngeal flora predominated in infections that originated from head and neck wounds and abscesses, and bites, and those from the gastrointestinal tract predominated in infections that originated from peritonitis, abdominal abscesses, and decubitus ulcers. CONCLUSIONS: Many infections that follow trauma in children involve multiple organisms. PMID:9639177

Brook, I

1998-01-01

15

Odontogenic infection involving the secondary fascial space in diabetic and non-diabetic patients: a clinical comparative study  

PubMed Central

Objectives This retrospective study was performed to evaluate the clinical impact of diabetes mellitus on the prognosis in secondary space infection. Materials and Methods Medical records, radiographic images, computed tomography, and microbial studies of 51 patients (25 diabetic patients and 26 non-diabetic patients) were reviewed. Patients were diagnosed as secondary fascial space infections with odontogenic origin and underwent treatment at Chonnam National University Hospital, in Department of Oral and Maxillofacial Surgery, from January 2007 to February 2009. Results Compared to patients without diabetes, patients with diabetes were presented with the following characteristics: older age (diabetic patients: 62.9 years, non-diabetic patients, 47.8 years), more spaces involved (diabetic patients, 60%; non-diabetic patients, 27.3%), more intense treatment, longer hospitalization (diabetic patients, 28.9 days; non-diabetic patients, 15.4 days), higher white blood cell and C-reactive protein values, higher incidence of complication (diabetic patients, 40%; non-diabetic patients, 7.7%), and distinctive main causative microorganisms. Conclusion These results suggest that the prognosis of diabetic patients is poorer than that of non-diabetic patients in secondary space infections since they had greater incidence rates of involved spaces, abnormal hematologic findings, more complications, and additional procedures, such as tracheostomy. PMID:24471039

Chang, Je-Shin; Yoo, Kil-Hwa; Yoon, Sung Hwan; Ha, Jiwon; Jung, Seunggon; Kook, Min-Suk; Park, Hong-Ju; Ryu, Sun-Youl

2013-01-01

16

Genotypic Diversity of Anaerobic Isolates from Bloodstream Infections?  

PubMed Central

Accurate species determination for anaerobes from blood culture bottles has become increasingly important with the reemergence of anaerobic bacteremia and prevalence of multiple-drug-resistant microorganisms. Our knowledge of the taxonomical diversity of anaerobes that cause bloodstream infections is extremely limited, because identification historically has relied on conventional methods. Over a 5-year period, we profiled anaerobic bacteremia at a large tertiary care hospital with 16S rRNA gene sequencing to gain a better understanding of the taxonomical diversity of the bacteria. Of 316 isolates, 16S rRNA gene sequencing and phylogenetic analysis identified 316 (100%) to the genus or taxonomical group level and 289 (91%) to the species level. Conventional methods identified 279 (88%) to the genus level and 208 (66%) to the species level; 75 (24%) were misidentified at the species level, and 33 (10%) results were inconclusive. High intragenus variability was observed for Bacteroides and Clostridium species, and high intraspecies variability was observed for Bacteroides thetaiotaomicron and Fusobacterium nucleatum. Sequence-based identification has potential benefits in comparison to conventional methods, because it more accurately characterizes anaerobes within taxonomically related clusters and thereby may enable better correlation with specific clinical syndromes and antibiotic resistance patterns. PMID:18322067

Simmon, Keith E.; Mirrett, Stanley; Reller, L. Barth; Petti, Cathy A.

2008-01-01

17

Diagnosis of anaerobic infection by gas chromatographic estimation of volatile fatty acids.  

PubMed

Nine hundred and eighty-one fluid specimens were analysed by culture and by gas chromatography. The presence of obligate anaerobes was best predicted if one or more of the volatile acids isobutyric, butyric, isovaleric, valeric, isocaproic or caproic acid were detected in the specimen. Propionic acid was not a good indicator of the presence of obligate anaerobes. The agreement between gas chromatography and culture for obligate anaerobes in the main study (841 specimens, 232 culture positive) was: co-positivity 82%; co-negativity 92%. Falsely negative specimens contained anaerobes which had probably not produced sufficient of their characteristic volatile fatty acids to be detected. When it was the sole infecting anaerobe, Bacteroides fragilis seemed especially likely to be missed by gas chromatography. Forty-five of the 51 falsely positive specimens probably represented failure to culture anaerobes rather than spurious volatile fatty acid detection. PMID:7160368

Nichols, W W; Crow, M R; Nicholls, K

1982-12-01

18

Bacteroides fragilis bacteremia and infected aortic aneurysm presenting as fever of unknown origin: diagnostic delay without routine anaerobic blood cultures.  

PubMed

We report the case of a 71-year-old male with Bacteroides fragilis bactermia and infected aortic aneurysm that went undiagnosed, in part, because routine anaerobic blood cultures were not obtained. Bacteremia caused by anaerobes has been reported to be declining, and recommendations to discontinue routine anaerobic blood cultures have been implemented in some hospitals. To our knowledge, this is the first report of an anaerobic bacteremia and infection that had a delay in diagnosis due to this change in blood-culturing protocol. The potential impact of deleting anaerobic blood cultures from routine protocols is discussed. PMID:10524981

O'Donnell, J A; Asbel, L E

1999-11-01

19

Rapid presumptive diagnosis of anaerobic infections in animals by gas-liquid chromatography.  

PubMed

The detection of volatile fatty acids (VFA) by gas chromatography of 85 purulent specimens from abscesses or pyogenic infections in cats, dogs, rodents, and ruminants was compared with the results of bacteriologic culturing, and proved to be a rapid means of presumptively diagnosing anaerobic infections. Of 83 bacteriologically positive specimens, 52 (61%) yielded obligate anaerobes and in 50 specimens, 1 or more VFA (butyric acid, isobutyric acid, valeric acid, isovaleric acid, caproic acid, or isocaproic acid) was detected. Forty-six specimens were positive for culturing of anaerobes and for detection of 1 or more of these VFA. By contrast, pus from infections caused by (facultative) aerobic microorganisms contained no VFA or only acetic and/or propionic acid. PMID:2679251

van den Bogaard, A E; Hazen, M J; Maes, J H

1989-09-01

20

[Rapid diagnosis of anaerobic infections by means of the direct gaschromatographic study of clinical materials].  

PubMed

Current methods for isolation and identification of obligately anaerobic bacteria are laborious and time-consuming. Direct gas-liquid chromatography of purulent and serous specimens for short-chain fatty acids allows a presumptive diagnosis of anaerobic infection. Good correlation was found for the cultural recovery of anaerobic bacteria and the presence of propionic acid in concentrations of greater than or equal to 1 muMol/ml, isobutyric, butyric, isovaleric, valeric, isocaproic and caproic acid at greater than or equal to 0.1 muMol/ml, and succinic acid at greater than or equal to 2 muMol/ml (either as single acids or in combination). Specimens yielding no anaerobic bacteria in culture contained only acetic, lactic and small amounts of succinic acid, but none of the volatile acids. PMID:7394465

Wüst, J

1980-03-01

21

Risk factors for anaerobic bloodstream infections in bone marrow transplant recipients.  

PubMed

The incidence of anaerobic bloodstream infections (BSI) in patients who underwent bone marrow transplantation (BMT) recently increased at our institution. A retrospective case-control study of patients undergoing BMT from January 1995 through December 1998 was performed to determine the microbiological characteristics, epidemiology, and outcome of anaerobic BSI and to identify independent risk factors for infection. Anaerobic BSI occurred in 23 patients, for a rate of 4 BSIs per 100 BMT procedures, and it accounted for 17% of all BSIs that occurred during the study period. Infection occurred at a mean (+/- standard deviation) of 7+/-4 days after BMT and 7+/-5 days after the onset of neutropenia. Fusobacterium nucleatum was the most frequently isolated pathogen (in 17 patients), followed by Leptotrichia buccalis (in 4), Clostridium septicum (in 1), and Clostridium tertium (in 1). Two case patients (9%) died. Severity of mucositis was an independent predictor of anaerobic BSI (odds ratio, 4.4; P=.01). Controlling mucositis is critical for the prevention of anaerobic BSI in this patient population. PMID:11438899

Lark, R L; McNeil, S A; VanderHyde, K; Noorani, Z; Uberti, J; Chenoweth, C

2001-08-01

22

Calcifying odontogenic cyst associated with an orthokeratinized odontogenic cyst.  

PubMed

Odontogenic tumors composed of two or more distinct types of lesions are unusual. In this paper, a case of an odontogenic lesion characterized by simultaneous occurrence of areas of calcifying odontogenic cyst (COC) and orthokeratinized odontogenic cyst (OOC) is described. The lesion was asymptomatic and presented at the radiographic examination as a unilocular well-delimited radiolucency extending from left incisor to right premolar area in the mandible. To date, this is the first report of COC associated with an OOC. PMID:20614303

de Fátima Bernardes, Vanessa; de Lacerda, Júlio César Tanos; de Aguiar, Maria Cássia Ferreira; Gomez, Ricardo Santiago

2008-12-01

23

Anaerobic  

E-print Network

Applying animal manure to crop land is a traditional and effective means of recycling nutrients and improving the structure of the soil by adding organic matter and biological activity. Applying manure can also enhance animal and crop production by reducing the costs of fertilizer. However, manure application can cause odor complaints from neighbors and surrounding communities. Appropriate application methods and management practices based on odor emission and dispersion principles can effectively reduce odor concerns during manure application. This fact sheet presents a basic understanding of odors and odor dispersion and highlights best management practices for controlling odors during manure application. What Is Odor? Odor is an unpleasant smell caused by odorous gases and volatile organic compounds (VOCs). These volatile organic compounds are organic acids, and they evaporate easily. Under ideal anaerobic conditions, manure is degraded by acid-forming microorganisms into volatile organic compounds (Figure 1). These compounds are further metabolized by methane-producing bacteria into methane, carbon dioxide, and water, which are odor-free compounds. If conditions are not correct for methane bacteria, excess volatile organic compounds are generated. Manure stored in a well-functioning treatment lagoon (purple lagoon) will be less odorous than manure from non-treatment

Lingying Zhao; Jonathan N. Rausch; Tamara L. Combs

24

Peripheral squamous odontogenic tumor.  

PubMed

A case of peripheral squamous odontogenic tumor is described in a 60-year-old female who presented with a sessile growth in the right posterior mandible. Radiographic examination revealed no evidence of a central lesion in bone. With the characteristic histopathological picture of benign-appearing islands of squamous epithelium scattered randomly against a background of mature fibrous connective tissue, the tumor was diagnosed as peripheral squamous odontogenic tumor (PSOT). The epithelial islands showed peripheral cuboidal or flattened cells, microcyst formation, individual cell keratinization, and keratin pearl formation. PMID:22945726

Malathi, N; Radhika, T; Thamizh, Chelvan H; Nandakumar, N

2012-01-01

25

The use of metronidazole for the treatment of non-specific anaerobic infections in dogs and cats  

Microsoft Academic Search

The role of anaerobes in the pathogenesis of non-specific infections in man has become increasingly apparent in recent years as a result of improved microbiological techniques which have facilitated their isolation and identification from pathological specimens. Such organisms as Bacteroides, Eubacteria and anaerobic streptococci are frequently isolated from lesions in a variety of human tissues, including brain, lung, mammary gland

P. Carwardine

1983-01-01

26

Odontogene pyogene Infektionen  

Microsoft Academic Search

Zusammenfassung Das Patientengut mit odontogenen pyogenen Infektionen im Zeitraum von 1987-1997 der Klinik für Mund-, Kiefer- und Gesichtschirurgie der Klinikum Erfurt GmbH wurde in einer retrospektiven Studie analysiert. Dabei wurden Aussagen über die Häufigkeit, die Schwere und die Therapie der Erkrankung getroffen, wobei die gesellschaftlichen Veränderungen im Einzugsgebiet Auswirkungen auf das Überweisungsverhalten und den Krankheitsverlauf belegen. Odontogene pyogene Infektionen sind

J. Piesold; S. Vent; S. Schönfeldt

1999-01-01

27

Hybrid odontogenic tumor of calcifying odontogenic cyst and ameloblastic fibroma  

Microsoft Academic Search

Odontogenic tumors composed of 2 distinct types of lesions are unusual. We report an odontogenic tumor that was composed of calcifying odontogenic cyst and ameloblastic fibroma that occurred in the right posterior maxilla of a 22-year-old Korean woman. The tumor had a cystic component with an ameloblastic epithelial lining and conglomerates of so-called ghost cells, and there were deposits of

Jung Hoon Yoon; Hyung Jun Kim; Jong In Yook; In Ho Cha; Gary L Ellis; Jin Kim

2004-01-01

28

Odontogenic Cysts, Odontogenic Tumors, Fibroosseous, and Giant Cell Lesions of the Jaws  

Microsoft Academic Search

Odontogenic cysts that can be problematic because of recurrence and\\/or aggressive growth include odontogenic keratocyst (OKC), calcifying odontogenic cyst, and the recently described glandular odontogenic cyst. The OKC has significant growth capacity and recurrence potential and is occasionally indicative of the nevoid basal cell carcinoma syndrome. There is also an orthokeratinized variant, the orthokeratinized odontogenic cyst, which is less aggressive

Joseph A. Regezi

2002-01-01

29

Odontogenic Tumor Markers - An Overview  

PubMed Central

The practice of pathology is currently undergoing significant change, due to advances in the field of molecular pathology. Tumor markers are molecules that help the pathologists for confirmatory diagnosis of histopathologically confounding lesions. Odontogenic tumors are relatively rare with estimated incidence of less than 0.5 cases/ 100,000 population per year. Odontogenic tumors can pose diagnostic challenges because of overlapping histology. But, appropriate diagnosis is crucial as their treatment modality and prognosis differ; in these situations tumor markers can be helpful. But lack of comprehensive literature on specific markers for odontogenic tumors imposes pathologists to think aimlessly about various markers to arrive at an appropriate diagnosis. With this background, it is our attempt at compiling diagnostically important odontogenic tumor markers. Also, a note is added on tumor behaviour studies in common clinically important odontogenic tumors: Ameloblastoma and Keratocystic odontogenic tumor. How to cite this article: Premalatha B R, Patil S, Rao R S, Reddy N P, Indu M. Odontogenic Tumor Markers - An Overview. J Int Oral Health 2013; 5(2):65-75. How to cite this article: Premalatha B R, Patil S, Rao R S, Reddy N P, Indu M. Odontogenic Tumor Markers - An Overview. J Int Oral Health 2013; 5(2):65-75 PMID:24155593

Premalatha, B R; Patil, Shankargouda; Rao, Roopa S; Reddy, Narendranatha P; Indu, M

2013-01-01

30

Association experiments with aerobic and anaerobic pathogens: a model of in-vitro susceptibility testing in mixed infections. Activity of enoxacin, clindamycin, and metronidazole  

Microsoft Academic Search

Summary In infections of polymicrobial etiology, it seems mandatory to combine an antibiotic with marginal activity against anaerobes with an anti-anaerobic drug, e. g. metronidazole or clindamycin. We investigated the effect of associations of anaerobic and facultatively anaerobic pathogens on MBCs of enoxacin, clindamycin, metronidazole, and combinations of enoxacin plus clindamycin or metronidazole. Single testing, and associations ofBacteroides fragilis withEscherichia

W. R. Heizmann; R. Schmid; F. Heilmann; H. Werner

1989-01-01

31

Bone and joint infections due to anaerobic bacteria: an analysis of 61 cases and review of the literature.  

PubMed

The diagnosis of anaerobic bone and joint infections (BJI) were underestimated before the advent of molecular identification and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). We report 61 cases of anaerobic infections based on our 4-year experience with the management of BJI. A total of 75% of cases were post-surgical infections, associated with osteosynthesis devices (65%). Early infections occurred in 27% of cases, delayed infections in 17.5% of cases, and late infections in 55% of cases. We recorded 36 species of 93 anaerobic strains using MALDI-TOF MS (91) and molecular methods (2). We identified 20 strains of Propionibacterium acnes, 13 of Finegoldia magna, six of Peptoniphilus asaccharolyticus, and six of P. harei. Polymicrobial infections occurred in 50 cases. Surgical treatment was performed in 93.5% of cases. The antibiotic treatments included amoxicillin (30%), amoxicillin-clavulanic acid (16%), metronidazole (30%), and clindamycin (26%). Hyperbaric oxygen therapy was used in 17 cases (28%). The relapse rate (27%) was associated with lower limbs localization (p?=?0.001). P. acnes BJI was associated with shoulder (p?=?0.019), vertebra (p?=?0.021), and head flap localization (p?=?0.011), and none of these cases relapsed (p?=?0.007). F. magna BJI was associated with ankle localization (p?=?0.014). Anaerobic BJI is typically considered as a post-surgical polymicrobial infection, and the management of this infection combines surgical and medical treatments. MALDI-TOF MS and molecular identification have improved diagnosis. Thus, physicians should be aware of the polymicrobial nature of anaerobic BJI to establish immediate broad-spectrum antibiotic treatment during the post-surgical period until accurate microbiological results have been obtained. PMID:24577953

Walter, G; Vernier, M; Pinelli, P O; Million, M; Coulange, M; Seng, P; Stein, A

2014-08-01

32

In Vitro Activity of Moxifloxacin against 923 Anaerobes Isolated from Human Intra-Abdominal Infections  

PubMed Central

The in vitro activity of moxifloxacin against 923 recent anaerobic isolates obtained from pretreatment cultures in patients with complicated intra-abdominal infections was studied using the CLSI M11-A-6 agar dilution method. Moxifloxacin was active against 87% (96 of 110) Bacteroides fragilis strains at ?1 ?g/ml and 87% (79 of 90) B. thetaiotaomicron strains at ?2 ?g/ml. Species variation was seen, with B. uniformis, B. vulgatus, Clostridium clostridioforme, and C. symbiosum being least susceptible and accounting for most of the resistant isolates; excluding the aforementioned four resistant species, 86% (303 of 363) of Bacteroides species isolates and 94% (417 of 450) of all other genera and species were susceptible to ?2 ?g/ml of moxifloxacin. Overall, moxifloxacin was active against 763 of 923 (83%) of strains at ?2 ?g/ml, supporting its use as a monotherapy for some community-acquired intra-abdominal infections. PMID:16377680

Goldstein, Ellie J. C.; Citron, Diane M.; Warren, Yumi A.; Tyrrell, Kerin L.; Merriam, C. Vreni; Fernandez, Helen

2006-01-01

33

The odontogenic keratocyst: orthokeratinized variant.  

PubMed

The histopathologic and clinical features of sixty cases of orthokeratinized odontogenic cysts were compared with those of odontogenic keratocysts (typically parakeratinized). According to the results of this study, the orthokeratinized odontogenic cyst appears to be a distinct clinicopathologic entity. This cyst is histologically characterized by a thin, uniform, epithelial lining with orthokeratinization and a subjacent granular cell layer. The basal cells are usually cuboidal or flattened. Clinically, the orthokeratinized cyst is a single cyst, shows a predilection for males, and is most often found in the second to the fifth decade, it appears most commonly as a dentigerous cyst in the posterior mandible. The orthokeratinized cyst shows little clinical aggressiveness. Follow-up of twenty-four patients revealed only one recurrence; of nineteen patients evaluated, none had features of the basal cell nevus-bifid rib syndrome. It is suggested that this cyst be called odontogenic keratocyst, orthokeratinized variant. PMID:6166916

Wright, J M

1981-06-01

34

[The odontogenic keratocyst--odontogenic cyst or benign tumor?].  

PubMed

The odontogenic keratocyst is the third most common cyst of the jaws, after the follicular and radicular cyst. Keratocysts most commonly occur as single lesions in the jaw of otherwise healthy persons. Multiple odontogenic keratocysts are a well-recognized feature of the nevoid basal cell carcinoma syndrome. The mandible, especially the third molar region, the angle of the mandible and the ascending ramus are involved far more frequently than the maxilla. Clinically, the cysts often remain asymptomatic and there are two specific histological entities: the orthokeratinized and the parakeratinized odontogenic keratocyst. Different surgical treatment options like marsupialization, enucleation with curettage or peripheral ostectomy, and osseous resection (marginal or segmental) have been discussed in the literature with variable rates of recurrence. Besides a predilection for recurrence, the keratocysts, in contrast to other odontogenic cysts, show a more aggressive clinical behavior and demonstrate a high mitotic count and higher turnover rate of the epithelium. This led to the tentative suggestion that the keratocyst might be a benign cystic neoplasm rather than simply an odontogenic cyst. PMID:15771334

Bornstein, Michael M; Filippi, Andreas; Altermatt, Hans Jörg; Lambrecht, J Thomas; Buser, Daniel

2005-01-01

35

Calretinin expression in odontogenic cysts.  

PubMed

Calretinin is a calcium-binding protein with a possible role as a calcium buffer, calcium-sensor, or regulator of apoptosis. Calretinin is expressed in neural tissue, is a specific marker of mesothelial cells, and has been demonstrated in the odontogenic epithelium during odontogenesis in rat molar tooth germs. Moreover, it has been found to be expressed in a high proportion of solid, unicystic, and multicystic ameloblastomas, whereas, on the contrary, no positive staining has been found in odontogenic keratocysts, residual cysts, and dentigerous cysts. The purpose of this study was to evaluate calretinin expression in radicular cysts, follicular cysts, orthokeratinized keratocysts, and parakeratinized keratocysts. A total of 70 odontogenic cysts, 24 radicular cysts, 24 follicular cysts, and 22 odontogenic keratocysts (10 orthokeratinized keratocysts, 12 parakeratinized keratocysts) were evaluated. All the radicular cysts, follicular cysts, and orthokeratinized keratocysts were negative. However in 8 of 12 parakeratinized keratocysts, there was a positivity to calretinin in the parabasal-intermediate layers of the cyst epithelium. This positivity to calretinin in the parabasal layers in parakeratinized keratocysts, similar to that found for other markers like PCNA and p53, could point to an abnormal control of the cell cycle and could help to explain the differences in the clinical and pathologic behavior of odontogenic keratocysts, in particular the differences found between orthokeratinized keratocysts and parakeratinized keratocysts. PMID:12814222

Piattelli, Adriano; Fioroni, Massimiliano; Iezzi, Giovanna; Rubini, Corrado

2003-06-01

36

Minor trauma triggering cervicofacial necrotizing fasciitis from odontogenic abscess  

PubMed Central

Necrotizing fasciitis (NF) of the face and neck is a very rare complication of dental infection. Otolaryngologists and dentists should be familiar with this condition because of its similarity to odontogenic deep neck space infection in the initial stages, its rapid spread, and its life-threatening potential. Trauma has been reported to be an important predisposing factor for NF of the face. In this paper, we describe the presentation and treatment of a 62-year-old man who developed NF of the face and neck following bilateral odontogenic deep neck space abscesses. The disease progressed rapidly, with necrosis of the skin, after the patient inflicted minor trauma in the form of application of heated medicinal leaves. The organism isolated in culture from pus was Acinetobacter sp. The comorbid conditions in our patient were anemia and chronic alcoholism. The patient was managed by immediate and repeated extensive debridements and split-skin grafting. PMID:19561990

Jain, Shraddha; Nagpure, Prakash S; Singh, Roohie; Garg, Deepika

2008-01-01

37

Comparative In Vitro Activities of Ertapenem (MK-0826) against 469 Less Frequently Identified Anaerobes Isolated from Human Infections  

PubMed Central

We studied the in vitro activity of ertapenem against 469 less frequently identified anaerobes from 11 genera and 52 species isolated from human infections. Ertapenem was uniformly active against 460 of 469 (98%) strains at concentrations of ?4 ?g/ml. Only 4 of 14 Clostridium difficile, 1 of 11 Clostridium innocuum, and 4 of 6 Lactobacillus sp. strains required ertapenem concentrations of ?8 ?g/ml for inhibition. PMID:11897608

Goldstein, Ellie J. C.; Citron, Diane M.; Merriam, C. Vreni; Warren, Yumi A.; Tyrrell, Kerin L.; Fernandez, Helen

2002-01-01

38

Comparative In Vitro Activities of Ertapenem (MK-0826) against 1,001 Anaerobes Isolated from Human Intra-Abdominal Infections  

PubMed Central

By using an agar dilution method, the comparative in vitro activities of ertapenem (MK-0826) were studied against 1,001 anaerobes isolated from human intra-abdominal infections in 17 countries worldwide. MK-0826 was uniformly active against all isolates, including all Bacteroides fragilis group species isolates, with the exception of 12 of 61 (20%) strains of Bilophila wadsworthia, 3 strains of lactobacilli, and 1 isolate of Acidaminococcus fermentans. Geographical variation in activity was not observed. PMID:10952584

Goldstein, Ellie J. C.; Citron, Diane M.; Vreni Merriam, C.; Warren, Yumi; Tyrrell, Kerin L.

2000-01-01

39

A rare presentation of hybrid odontogenic tumor involving calcifying cystic odontogenic tumor and plexiform ameloblastoma  

PubMed Central

A hybrid odontogenic tumor comprising two distinct lesions is extremely rare. We presented a hybrid odontogenic tumor composed of a calcifying cystic odontogenic tumor (CCOT) and a plexiform ameloblastoma. This tumor was observed in the anterior area of the mandible of a 17-year-old Indian male. Masses of ghost epithelial cells with the characteristics of CCOT were seen in the lining of the cyst. The odontogenic epithelia with the features of plexiform ameloblastoma were also observed. PMID:24124318

Chaubey, Snehal S.; Mishra, Sunil S.; Degwekar, Shirish S.; Chaubey, Saujanya

2013-01-01

40

Odontogenic carcinoma with dentinoid: a new odontogenic carcinoma.  

PubMed

Dentinoid is an integral part of some odontogenic tumors. This article describes the clinico-pathological features of three cases of odontogenic carcinomas with dentinoid (OCD). A comparison of these with previously reported cases of dentinoid-producing epithelial odontogenic tumors allowed us to identify another six cases that may be considered as examples of OCD. Six cases occurred in the mandible and three in the maxilla, all developing behind the canines. There was no sex predilection (five men and four women; age range 14-61 years, mean 38.1). Pain or discomfort was mentioned in five cases, four of which showed tooth resorption. All cases appeared initially as well-defined radiolucencies, five of which showed variable amounts of calcified material. Recurrences were recorded in three instances, but no evidence of metastasis has been found. Seven cases were composed predominantly or entirely of clear cells, usually with minimal cellular atypia and variable mitotic activity; however, in all cases there was evidence of tumor infiltration into adjacent tissues, including the presence of perineural invasion in two tumors. Those cases in which no reference was made to the presence of clear cells exhibited evident mitotic activity and cellular pleomorphism. The epithelium in OCD does not produce buds or enamel organ-like structures such as those found in ameloblastic fibro-dentinoma and this tumor does not contain a mesenchyme-like connective tissue resembling dental papilla as observed in several mixed odontogenic tumors. Based on the existing data and the present series of cases, OCD appears to represent a distinct entity. PMID:25409850

Mosqueda-Taylor, Adalberto; Neville, Brad W; Tatemoto, Yukihiro; Ogawa, Ikuko; Takata, Takashi

2014-12-01

41

[Studies on keratocystic odontogenic tumors].  

PubMed

Keratocystic odontogenic tumors (KCOTs, previously known as odontogenic keratocysts) are aggressive, noninflammatory jaw lesions with a putative high growth potential and a propensity for recurrence. This article puts together a summary of the serial studies related to KCOTs undertaken by the author's research group in recent years. Intraosseous jaw cysts with a solely orthokeratinized lining epithelium have been suggested to differ from the typical KCOTs. We report 20 cases of such cyst type under the term of 'orthokeratinized odontogenic cyst (OOC)'. Apart from the presence of a keratinizing epithelial lining, the OOC lacks the other histological features of KCOT, exhibits little if any tendency to recur, has no apparent association with NBCCS, may be cured by simple enucleation, and may thus constitute its own clinical entity. Mutations in PTCH1 gene are responsible for NBCCS and are related in tumors associated with this syndrome. We have so far detected 26 PTCH1 mutations (2 mutations occurred twice) in 10 out of 34 (29.4%) sporadic and 14 out of 16 (87.5%) NBCCS-associated KCOTs. The 26 mutations consisted of 10 frameshift, 2 nonsense, 3 aberrant splicing, 4 in-frame insertion/deletion/ duplication and 7 missense mutations. Two missense mutations in PTCH2 were also detected in 2 out of 15 NBCCS related KCOT patients. By contrast, no pathogenic mutation was detected in SMO. Thus, our data, together with reports from other groups, indicate that defects of PTCH1 are involved in the pathogenesis of syndromic as well as sporadic KCOTs. The pathogenic role of PTCH2 requires further investigation. A series of in vitro studies on bone resorption of KCOTs and ameloblastomas were undertaken by this group. The results indicate that odontogenic lesions could promote bone resorption in vitro and it is likely to be related to some of the cytokines secreted by the lesions. PMID:19221557

Li, Tie-jun; Sun, Li-sha; Luo, Hai-yan; Yuan, Jun-wei; Gao, Li; Gu, Xiao-mei; Li, Xue-fen; Xu, Li-li

2009-02-18

42

Odontogenic cysts, odontogenic tumors, fibroosseous, and giant cell lesions of the jaws.  

PubMed

Odontogenic cysts that can be problematic because of recurrence and/or aggressive growth include odontogenic keratocyst (OKC), calcifying odontogenic cyst, and the recently described glandular odontogenic cyst. The OKC has significant growth capacity and recurrence potential and is occasionally indicative of the nevoid basal cell carcinoma syndrome. There is also an orthokeratinized variant, the orthokeratinized odontogenic cyst, which is less aggressive and is not syndrome associated. Ghost cell keratinization, which typifies the calcifying odontogenic cyst, can be seen in solid lesions that have now been designated odontogenic ghost cell tumor. The glandular odontogenic cyst contains mucous cells and ductlike structures that may mimic central mucoepidermoid carcinoma. Several odontogenic tumors may provide diagnostic challenges, particularly the cystic ameloblastoma. Identification of this frequently underdiagnosed cystic tumor often comes after one or more recurrences and a destructive course. Other difficult lesions include malignant ameloblastomas, calcifying epithelial odontogenic tumor, squamous odontogenic tumor, and clear-cell odontogenic tumor. Histologic identification of myxofibrous lesions of the jaws (odontogenic myxoma, odontogenic fibroma, desmoplastic fibroma) is necessary to avoid the diagnostic pitfall of overdiagnosis of similar-appearing follicular sacs and dental pulps. Fibroosseous lesions of the jaws show considerable microscopic overlap and include fibrous dysplasia, ossifying fibroma, periapical cementoosseous dysplasia, and low-grade chronic osteomyelitis. The term fibrous dysplasia is probably overused in general practice and should be reserved for the rare lesion that presents as a large, expansile, diffuse opacity of children and young adults. The need to use clinicopathologic correlation in assessing these lesions is of particular importance. Central giant cell granuloma is a relatively common jaw lesion of young adults that has an unpredictable behavior. Microscopic diagnosis is relatively straightforward; however, this lesion continues to be somewhat controversial because of its disputed classification (reactive versus neoplastic) and because of its management (surgical versus. medical). Its relationship to giant cell tumor of long bone remains undetermined. PMID:11904346

Regezi, Joseph A

2002-03-01

43

Anti-anaerobic activity of serum from patients treated with tigecycline for skin/soft tissue infections.  

PubMed

To gain additional data concerning the anti-anaerobic activity of tigecycline in serum, we analyzed blood samples from six patients with a complicated skin/soft tissue infection who were receiving IV tigecycline 50 mg every 12 h. Venous blood samples were obtained after multiple doses of tigecycline at 1, 6 and 12 h after the initiation of a 1 h IV infusion. Sera from these samples were tested to determine serum inhibitory and bactericidal activity over time against 4 anaerobic bacteria (Bacteroides fragilis, Peptoniphilus asaccharolyticus, Prevotella bivia and Finegoldia magna). An analysis of serum titers found that tigecycline exhibited early (1 h) and prolonged (12 h) inhibitory activity against each study isolate. Moreover, it provided bactericidal activity for 12 h against these strains with the exception of F. magna. Tigecycline was found to exhibit antibacterial activity at serum concentrations below the MICs of the anaerobic bacteria tested. This finding further supports that the antimicrobial activity of tigecycline can be greater than that suggested by the free fraction of drug and that serum appears to enhance this antibacterial activity. PMID:21376823

Stein, G E; Tyrrell, K L; Dybas, L A; Citron, D M; Nicolau, D P; Goldstein, E J C

2011-08-01

44

Demographic distribution of odontogenic cysts in Isfahan (Iran) over a 23-year period (1988-2010)  

PubMed Central

Background: Odontogenic cysts are relatively common lesions which can cause different complications. As demographic information is lacking in Iran and specially in Isfahan, the aim of this study was to determine the prevalence of odontogenic cysts according to age, gender and affected area among patients referring to the Oral Pathology Department of the Dental School of Isfahan University of Medical Sciences (Iran) over a 23-year period. Materials and Methods: A total of 7412 diagnosed lesions recorded in the Oral Pathology Department archives of Isfahan Dental School between 1988 and 2010 were reevaluated, then odontogenic cysts were separated through reviewing microscopic slides according to the 2005 World Health Organization classification and variables such as age, gender, the infected jaw, and its specific region were obtained by SPSS Version 16.0 from the recorded database. Results: 21.62% of the lesions were odontogenic cysts, of which 48.72% were inflammatory and 51.28% were developmental cysts. These cysts were more common in the mandible. The mean age of patients was 29.53 ± 16.1. Male to female ratio was 1.31:1. The four most frequent odontogenic cysts were radicular cysts (35.12%), dentigerous cysts (25.77%), odontogenic keratocysts (22.58%) and residual cysts (12.98%). Conclusion: Odontogenic cysts are fairly frequent jaw lesions (21.62%), of which radicular cyst was the most common cyst. The four most common lesions constituted a sum of 96.45% of the total. In general, the prevalence rates in our study are similar to the studies from other geographic parts of the world but with a lower incidence of inflammatory cysts, higher prevalence of dentigerous cysts and residual cysts and also mandibular predominance for residual cysts. PMID:23946730

Khosravi, Negin; Razavi, Sayed Mohammad; Kowkabi, Mahsa; Navabi, Amir Arsalan

2013-01-01

45

Comprehensive keratin profiling reveals different histopathogenesis of keratocystic odontogenic tumor and orthokeratinized odontogenic cyst.  

PubMed

Keratocystic odontogenic tumor is a cystic lesion that behaves more aggressively than other jaw cysts. One of its characteristic histologic features is a parakeratinized uniform layer of lining epithelium. A jaw cyst lined with orthokeratinized epithelium is called an orthokeratinized odontogenic cyst. These keratinized jaw cysts are thought to be separate entities, although their histopathogenesis has not been fully assessed. To better understand these lesions, we performed comprehensive immunohistochemical profiling of the keratin expression of each. Orthokeratinized odontogenic cysts expressed keratin 1, keratin 2, keratin 10, and loricrin, suggesting differentiation toward normal epidermis. Keratocystic odontogenic tumors expressed keratin 4, keratin 13, keratin 17, and keratin 19, which is a unique expression pattern reminiscent of a mucosal squamous epithelium and an epithelial appendage. In neonatal rat tooth germ, cells strongly positive for keratin 17 and keratin 19 were observed, specifically in the dental lamina, implying the origin of keratocystic odontogenic tumor. GLI2, a downstream effector of hedgehog signaling, was significantly expressed in keratocystic odontogenic tumor and basal cell carcinoma, accompanied with robust expression of keratin 17, mammalian target of rapamycin, and BCL2. The expression of these GLI2- or keratin 17-related factors was not significantly observed in orthokeratinized odontogenic cysts. These findings provide evidence to support the viewpoint that keratocystic odontogenic tumor and orthokeratinized odontogenic cyst are separate entities, and furthermore suggest their characteristic histology, pathogenesis, and biological behaviors. PMID:20801488

Aragaki, Tadanobu; Michi, Yasuyuki; Katsube, Ken-ichi; Uzawa, Narikazu; Okada, Norihiko; Akashi, Takumi; Amagasa, Teruo; Yamaguchi, Akira; Sakamoto, Kei

2010-12-01

46

Molecular and genetic aspects of odontogenic lesions.  

PubMed

In this article we outline the molecular findings of select odontogenic tumors. In each section, we briefly review selected the clinicoradiographic, histologic, immunologic features, focusing on the molecular findings and their applications in practice. The understanding of molecular pathobiology at various other organ sites has developed quite rapidly in recent years, however much remains unknown about the genetic profile of odontogenic tumors. Improved understanding of mutations in odontogenic tumors may clarify classification schema and elucidate targets for novel therapies. Molecular testing will no doubt improve our understanding of odontogenic tumor pathogenesis and will likely be, someday, an important component of routine clinical practice and its role will only increase in the coming years. PMID:25409852

Bilodeau, Elizabeth A; Prasad, Joanne L; Alawi, Faizan; Seethala, Raja R

2014-12-01

47

In Vitro Activities of Moxifloxacin against 900 Aerobic and Anaerobic Surgical Isolates from Patients with Intra-Abdominal and Diabetic Foot Infections  

PubMed Central

The in vitro activities of moxifloxacin, ciprofloxacin, levofloxacin, gatifloxacin, imipenem, piperacillin-tazobactam, clindamycin, and metronidazole against 900 surgical isolates were determined using NCCLS testing methods. Moxifloxacin exhibited good to excellent antimicrobial activity against most aerobic (90.8%) and anaerobic (97.1%) microorganisms, suggesting that it may be effective for the treatment of polymicrobial surgical infections. PMID:14982797

Edmiston, Charles E.; Krepel, Candace J.; Seabrook, Gary R.; Somberg, Lewis R.; Nakeeb, Atilla; Cambria, Robert A.; Towne, Jonathan B.

2004-01-01

48

Glandular Odontogenic Cyst of Maxilla  

PubMed Central

Glandular odontogenic cyst (GOC) is a rare developmental lesion that is considered a distinct entity because of its uncommon histopathological characteristics. It has morphological similarities to other lesions, which makes its diagnosis challenging for pathologists. It strikes distinct age groups, with an average patient age being 50 years. This lesion can involve either jaw, but the anterior region of the mandible is the most commonly affected area. It exhibits a tendency toward recurrence when conservative treatment is administered. It is believed that the low prevalence of GOC in the literature is due not only to its rarity, but also to the fact that its main characteristics are also found in other pathological entities. We report here radiologic-pathologic features of GOC of the maxilla in a 17-year-old female patient. PMID:22267989

Guruprasad, Yadavalli; Chauhan, Dinesh Singh

2011-01-01

49

Orofacial and Odontogenic Infections in the Elderly  

Microsoft Academic Search

The increasing retention of teeth into advanced age places the present cohort of older people at greater risk for serious\\u000a dental disease than previous cohorts. With advancing age, older individuals go to the doctor more but to the dentist less.\\u000a Therefore, physicians caring for older patients need to be aware of common oral diseases in order to suitably advise patients

Kenneth Shay

50

[Anaerobic septicemia following oropharyngeal infections (Lemierre's postanginal septicemia): a forgotten syndrome].  

PubMed

Two cases are reported of Lemierre's post-anginal septicemia. One was fatal due to extensive septic pneumonia, while the other presented as acute osteomyelitis. Both cases were preceded by oropharyngeal infections. PMID:6665544

Hirschel, B; Allaz, A F; Siegrist, C A

1983-12-31

51

Myelosuppression grading of chemotherapies for hematologic malignancies to facilitate communication between medical and dental staff: lessons from two cases experienced odontogenic septicemia  

PubMed Central

Background Odontogenic diseases can be a risk factor for life-threatening infection in patients with hematologic malignancies during chemotherapy that induces myelosuppression of variable severity. Previous studies noted the necessity of the elimination of all odontogenic foci before hematopoietic stem cell transplantation. To enable planning for the adequate dental intervention, the oral medicine team must understand the general status of patient and the intensity of the chemotherapy, which is sometimes difficult to be fully appreciated by dental staff. Therefore, a simplified grading would facilitate the sharing of information between hematologists, dentists and oral hygienists. This study aimed to introduce our myelosuppression grading of chemotherapies for hematologic malignancies and analyze the timing of occurrence of severe odontogenic infection. Methods 37 patients having received various chemotherapies for hematologic malignancies were enrolled. The chemotherapy regimens were classified into four grades based on the persistency of myelosuppression induced by chemotherapy. Mild myelosuppressive chemotherapies were classified as grade A, moderate ones as grade B, severe ones as grade C, and chemotherapies that caused severe myelosuppression and persistent immunodeficiency (known as conditioning regimens for transplant) as grade D. The timing of occurrence of severe odontogenic infection was retrospectively investigated. Results Two patients (5.4%) had severe odontogenic infections after grade B or C chemotherapy. One occurred after extraction of non-salvageable teeth; the other resulted from advanced periodontitis in a tooth that could not be extracted because of thrombocytopenia. Both were de novo hematologic malignancy patients. During grade D chemotherapy, no patients had severe odontogenic infections. Conclusions The simplified grading introduced in this study is considered a useful tool for understanding the myelosuppressive state caused by chemotherapy and facilitating communication between medical and dental staff. During the period around the primary chemotherapy, especially for de novo hematologic malignancy patients who often received grade B to C myelosuppression chemotherapy, caution should be exercised for severe odontogenic infection by the oral medicine team, irrespective of whether invasive treatment is to be performed. PMID:23957921

2013-01-01

52

Malignant odontogenic tumors: an update on selected tumors.  

PubMed

This is an update on selected odontogenic malignancies. The article deals with aspects of recognized odontogenic carcinomas, odontogenic sarcoma and a yet unrecognized entity, sclerosing odontogenic carcinoma. Odontogenic malignancies are exceedingly rare, complicating a thorough understanding of the biologic behavior, reproducible standardized diagnostic criteria, appropriate classification and clinical management. Without the knowledge of the tumor's biologic behavior, adequate clinical management is difficult and patient outcomes uncertain. The histopathologic features are emphasized as well as the more recent biomarker findings. These recent advances may facilitate further understanding of this group of malignancies and provide useful stratification to guide patient management. PMID:25409848

Richardson, Mary S; Muller, Susan

2014-12-01

53

Central odontogenic fibroma of the maxilla  

PubMed Central

The central odontogenic fibroma (COF) is a rare benign odontogenic mesenchymal tumor of jaw bones. The World Health Organization (WHO) recognizes two variants of COF namely: 1) Epithelial-rich type (WHO) and 2) epithelial-poor type (simple type). Rare variants like ossifying COF, COF associated with giant cell lesions, and amyloid have been documented. This article presents a case of an epithelial-rich variant of COF in a 24-year-old female. It presented as a bony swelling of the maxilla and appeared as a mixed lesion in radiographs. Histopathology showed a highly cellular fibrous connective tissue stroma with plump fibroblasts and long strands of odontogenic epithelium exhibiting mild eosinophilic to clear cytoplasm. Numerous cementum-like hematoxyphilic calcifications of various sizes akin to dentin or acellular cementum were observed. We believe that clinical and radiographic features of this case may add valuable knowledge to the already existing literature. PMID:24250106

Veeravarmal, V; Madhavan, R Nirmal; Nassar, M Mohamed; Amsaveni, R

2013-01-01

54

Keratocystic odontogenic tumour: systematic review  

PubMed Central

Objectives The aim of this review is to evaluate the principal clinical and conventional radiographic features of non-syndromic keratocystic odontogenic tumour (KCOT) by systematic review (SR), and to compare the frequencies between four global groups. Methods The databases searched were the PubMed interface of Medline and LILACS. Only those reports of KCOTs that occurred in a series of consecutive cases, in the reporting authors' caseload, were considered. Results 51 reports, of 49 series of cases, were included in the SR. 11 SR-included series were in languages other than English. KCOTs affected males more frequently and were three times more prevalent in the mandible. Although the mean age at first presentation was 37 years, the largest proportion of cases first presented in the third decade. The main symptom was swelling. Over a third were found incidentally. Nearly two-thirds displayed buccolingual expansion. Over a quarter of cases recurred. Only a quarter of all SR-included reported series of cases included details of at least one radiological feature. The East Asian global group presented significantly as well-defined, even corticated, multilocular radiolucencies with buccolingual expansion. The KCOTs affecting the Western global group significantly displayed an association with unerupted teeth. Conclusions Long-term follow-up of large series that would have revealed detailed radiographic description and long-term outcomes of non-syndromic KCOT was lacking. PMID:21159911

MacDonald-Jankowski, D S

2011-01-01

55

Prevalence of developmental odontogenic cysts in children and adolescents with emphasis on dentigerous cyst and odontogenic keratocyst (keratocystic odontogenic tumor).  

PubMed

Abstract Objective. To investigate the incidence and prevalence of developmental odontogenic cysts in children and adolescents and compare the features of the two most common types, dentigerous cyst and keratocystic odontogenic tumor (KCOT). Study design. A retrospective review in a series of 369 patients with all histological diagnoses of developmental odontogenic cysts in children (?12 years) and adolescents (13-18 years) was conducted. Results. Among these, 361 (97.8%) patients were diagnosed as dentigerous cyst (n = 281) and KCOT (n = 80), with the male-to-female ratios of dentigerous cyst and KCOT both being 2:1. The average age of the patients with KCOT was older than that of those with dentigerous cyst (14.7 years vs 11.8 years, p < 0.001). Dentigerous cyst (59.1%) was more common in children, but KCOT (78.8%) was more common in adolescents (p < 0.001). Dentigerous cyst (57.6%) predominantly located on the maxilla, but KCOT (60.3%) predominantly located on the mandible (p = 0.010). Conclusions. Adolescent patients with lesions located on the mandible would favor KCOT over dentigerous cyst. This study aids in better knowledge of the prevalence of developmental odontogenic cysts in a large pediatric population, and shows that a well-supported early diagnosis is indispensable for a more adequate treatment. PMID:24832690

Li, Nannan; Gao, Xing; Xu, Ziyuan; Chen, Zhuo; Zhu, Laikuan; Wang, Jinrui; Liu, Wei

2014-11-01

56

Head and Neck Pathology: SC13-1 UPDATE OF ODONTOGENIC TUMORS.  

PubMed

The latest WHO classification of odontogenic tumours was published in 2005. The classification has been used as a global standard for last 10 years but our knowledge of odontogenic tumors continues to evolve. At biennial meetings of International Association of Oral and Maxillofacial pathologists (IAOP), we have started discussions on classification of odontogenic tumors toward the next WHO Classification. I would like to introduce some subjects of discussion including cyst-tumor interface (odontogenic keratocyst vs keratocystic odontogenic tumor, glandular odontogenic cyst vs central mucoepidermoid carcinoma, calcifying odontogenic cyst vs ghost cell lesions); placement of adenomatoid odontogenic tumor (hamartoma vs neoplasia, epithelial tumor vs mixed tumor with dentin formation), clear cell odontogenic carcinoma with dentinoid formation; primary intraosseous squamous cell carcinoma vs sclerosing odontogenic carcinoma; classification based on inductive phenomenon of odontogenesis vs clinical behavior and others. Recent advances in molecular analyses of odontogenic tumors will be presented. I expect to exchange opinions on the new classification of odontogenic tumors. PMID:25188080

Takata, Takashi

2014-10-01

57

Odontogenic Inflammatory Processes of Head and Neck in Computed Tomography Examinations  

PubMed Central

Summary Background Infections of odontogenic origin are the most common cause of inflammatory disease of head and neck region. Computed tomography allows for defining localization and extent of inflammatory lesions, visualizes soft tissue involvement, presence of an abscess or an osteolytic lesion around causative tooth. The aim of this study was to assess pathways, by which odontogenic infections spread into respective deep head and neck structures in computed tomography examination, taking into account the following criteria: frequency of involvement of respective deep cervical spaces, possibility to determine a probable causative tooth and concordance with the results of clinical examination. Material/Methods Thirty-eight patients cervicofacial inflammatory disease had undergone CT examination of head and neck region with a 64-slice CT scanner after intravenous contrast administration. Results Abscess was reported in 30 (79%) cases, while inflammatory infiltration was diagnosed in remaining 8 (21%) patients. There was full concordance between radiological report and intraoperative report In 33 cases (87%). The most commonly involved cervical space was masticator space – 31 patients (82%), followed by submandibular space – 27 patients (71%). Dental examination was impossible in 29 patient because of trismus. During analysis of CT studies we evaluated maxillary and mandibular alveolar processes for presence of osteolytic bone lesions around causative teeth roots and we found them in 30 cases (79%). In 32 cases (84%) cervicofacial infection were of mandibular odontogenic origin. Conclusions In most cases CT study in patients suspected of odontogenic craniofacial infection revealed presence of an abscess, needing urgent surgery. Inflammatory infiltration of dental origin most frequently involves masticator space, followed by submandibular space. In most cases CT scanning allows for identification of causative teeth, especially when trismus makes detailed clinical examination impossible.

Wabik, Aleksandra; Hendrich, Barbara K.; Nienartowicz, Jan; Guzi?ski, Maciej; S?siadek, Marek J.

2014-01-01

58

Glandular odontogenic cyst: systematic review  

PubMed Central

Objectives The aim of this study was to evaluate the principal features of “glandular odontogenic cyst” (GOC), by systematic review (SR), and to compare their frequencies among four global groups. Methods The databases searched were the PubMed interface of MEDLINE and LILACS. Only those reports of GOCs that occurred in a series in the reporting authors' caseload were considered. All cases were confirmed histopathologically. Results 18 reports on 17 series of consecutive cases were included in the SR. GOC affected males twice as frequently and the mandible almost three times as frequently. The mean age at first presentation was 44 years, coincident with that of the Western global group, in which the largest proportion of reports and cases first presented in the second half of the fifth decade. However, age at presentation of GOCs in the East Asian and sub-Saharan African global groups was nearly a decade younger, this was significant. Six reports included details of at least one clinical presentation. Eight reports included at least one conventional radiological feature. There were some significant differences between global groups. The Western global group had a particular predilection for the anterior sextants of both jaws. The sub-Saharan African group displayed buccolingual expansion (as did the Latin American group) and tooth displacement in every case. 18% of GOCs recurred overall, except in the sub-Saharan African global group. Conclusions GOCs have a marked propensity to recur in most global groups. GOCs presented in older patients and with swellings, affected the anterior sextants of both jaws, and radiologically were more likely to present as a well-defined unilocular radiolucency with buccolingual expansion. Tooth displacement, root resorption and an association with unerupted teeth occurred in 50%, 30% and 11% of cases, respectively. PMID:20203274

MacDonald-Jankowski, D S

2010-01-01

59

Evaluation of bacterial spectrum of orofacial infections and their antibiotic susceptibility  

PubMed Central

Introduction: The inappropriate use of antibiotics has contributed to a worldwide problem of antimicrobial resistance. The objective of present study is to assess the most common microorganisms causing orofacial infections and their antimicrobial susceptibility to routinely used antibiotics in this part of India. Materials and Methods: Sixty eight patients with orofacial infection were selected on the basis of a series of predefined inclusion and exclusion criteria. Samples were collected under aseptic conditions and subjected to culture and antibiotic susceptibility testing. Descriptive statistics were provided. Results: A total of 64 aerobic and 87 anaerobic strains were isolated. The predominant bacteria were Streptococci viridans (64%), Prevotella (43%), Peptostreptococcus (26%), Porphyromonas (7%), and Fusobacterium (14%). The isolated strains seemed to be highly sensitive to the routinely used antibiotics such as amoxicillin – clavulanate and amoxicillin alone, clindamycin, and levofloxacin. In contrast, more resistance to erythromycin was observed. Conclusion: Amoxicillin still possesses powerful antimicrobial activity against major pathogens in orofacial odontogenic infections. Amoxicillin/clavulanate and clindamycin would also be advocated as being useful alternatives for the management of severe orofacial infections. However, the findings of this study indicate that erythromycin is of questionable benefit in the treatment of severe orofacial odontogenic infections. PMID:23482901

Chunduri, Nagendra S.; Madasu, Krishnaveni; Goteki, Venkateswara R.; Karpe, Tanveer; Reddy, Haranadha

2012-01-01

60

Synchronous ameloblastoma and orthokeratinized odontogenic cyst of the mandible.  

PubMed

The simultaneous occurrence of ameloblastomas with odontogenic cysts or other non-odontogenic lesions have already been described as combined lesions. However, we are unaware of any report in the English literature of simultaneous occurrence of ameloblastoma and orthokeratinized odontogenic cyst (OOC) occurring as completely distinct lesions. This report shows a case of synchronous ameloblastoma and OOC, located on posterior regions of the mandible, but in distinct sides. PMID:16968239

Fregnani, Eduardo Rodrigues; da Cruz Perez, Danyel Elias; Soares, Fernando Augusto; Alves, Fábio Abreu

2006-10-01

61

Calcifying odontogenic cyst with odontogenic keratocyst: a case report and review of the literature.  

PubMed

The calcifying odontogenic cyst (COC), first identified as a separate and distinct lesion by Gorlin et al. in 1962, is an uncommon benign lesion, consisting of a proliferation of odontogenic epithelium and scattered nests of ghost cells and calcifications that may form the lining of a cyst or present as a solid mass. The COC occurs alone or occasionally with odontomas or other odontogenic tumors, and it is this variable histology and clinical behavior that has raised the question of whether or not it is a cyst or a true neoplasm. The odontogenic keratocyst (OKC) is a locally aggressive odontogenic cyst lined by parakeratinizing epithelium that also exhibits characteristics of a neoplasm, including rapid growth, a high rate of recurrence when treated conservatively, and the presence of a gene mutation. We describe a patient diagnosed with an OKC of the mandible that arose simultaneously with a COC of the anterior maxilla. The occurrence of 2 "cystic neoplasms" in the same patient is an occurrence which to our knowledge has not been previously reported. We discuss the significance of the case and review the current literature regarding these lesions. PMID:20303045

Basile, John R; Klene, Carrie; Lin, Yi-Ling

2010-04-01

62

Odontogenic keratocyst: a clinical experience in Singapore.  

PubMed

The odontogenic keratocyst has been well documented and extensively studied. It is of particular interest because of its high recurrence rate and aggressive nature. The material for this study consisted of 70 cases of odontogenic keratocysts in predominantly ethnic Chinese patients who were treated from 1981 to 1996. The cases were retrospectively studied to compare characteristics of the lesion in this population with those in previous reports. Most of the patients in this series were 21 to 30 years of age. Association with an impacted mandibular third molar was found in more than 50% of the cases. The recurrence rate was 20% for 35 patients with a follow-up period of at least 5 years. The follow-up period for the whole series ranged from 1 to 16 years. Treatment was surgical enucleation with peripheral ostectomy. There were no significant differences in characteristics with respect to presentation and prognosis between this series and those described in previous publications. PMID:9830650

Chow, H T

1998-11-01

63

Epithelial odontogenic ghost cell tumour of the mandibular gingiva  

Microsoft Academic Search

The epithelial odontogenic ghost cell tumour (EOGCT) is considered as a solid `neoplastic' variant of the calcifying odontogenic cyst and is an uncommon lesion for which various names have been proposed over the years. We describe here an extraosseous case occurring on the edentulous mandibular gingiva in the right bicuspid area of a 70-year-old woman. The lesion was a painless

T Lombardi; R Küffer; R Di Felice; J Samson

1999-01-01

64

Immunohistochemical Analysis of P63 Expression in Odontogenic Lesions  

PubMed Central

P63 may have a role in tumorigenesis and cytodifferentiation of odontogenic lesions. We investigated the immunohistochemical expression of P63 in a total of 30 cases of odontogenic cysts and tumors. The percentage of positive cells was calculated in the lining of odontogenic cysts and islands of ameloblastoma. P63 expression was evident in all types of odontogenic lesions. P63 was expressed throughout the lining epithelium of odontogenic keratocyst except surface parakeratinized layer. In addition, calcifying odontogenic cyst showed P63 expression in all layers. In almost all radicular and dentigerous cysts, the basal and parabasal layers were immunoreactive. Peripheral cells of ameloblastoma expressed P63; however, stellate reticulum had weaker immunostaining. No significant difference in P63 expression was observed between studied lesions (P = 0.86). Expression of P63 in odontogenic lesions suggests that this protein is important in differentiation and proliferation of odontogenic epithelial cells. However, it seems that it could not be a useful marker to differentiate between aggressive and nonaggressive lesions. P63 also represents a progenitor or basal cell marker, and it is not expressed in mature differentiated cells. PMID:24350278

Atarbashi Moghadam, Saede; Atarbashi Moghadam, Fazele; Eini, Ebrahim

2013-01-01

65

Odontogenic Tumors, WHO 2005: Where Do We Go from Here?  

PubMed

As our knowledge of disease improves, its classification continually evolves. The last WHO classification of odontogenic tumors was 9 years ago and it is time for revision. We offer the following critique as a constructive, thought provoking challenge to those chosen to provide contemporary insight into the next WHO classification of odontogenic cysts, tumors, and allied conditions. PMID:25409849

Wright, John M; Odell, Edward W; Speight, Paul M; Takata, Takashi

2014-12-01

66

An approach to oral infections and their management  

Microsoft Academic Search

Oral infections can be odontogenic or nonodontogenic in origin. Odontogenic infections are most prevalent and include dental\\u000a caries, periodontal disease, and suppurative deep space infections. Nonodontogenic infections include sialadenitis and parotitis,\\u000a vesiculobullous gingivostomatitis, aphthous ulcers, oropharyngeal candidiasis, and severe oral mucositis in the immunocompromised\\u000a host. Clinical presentations can be variable. An understanding of the underlying anatomic structures, the oral microflora,

Mark W. Hull; Anthony W. Chow

2005-01-01

67

Multiple non-syndromic odontogenic keratocysts in three siblings.  

PubMed

Occurrence of multiple cysts (MC) involving the jaw is rare. When multiple, it is usually associated with a syndrome. Occurrence of MC without syndromic association is extremely rare. Multiple odontogenic cysts mostly could be odontogenic keratocysts or dentigerous cysts. Odontogenic keratocyst shows involvement of mandible over maxilla, with peak incidence in second and third decade and it is exceedingly rare before 10 years of age. However multiple odontogenic keratocysts found in children are often reflective of nevoid basal cell carcinoma syndrome. Here is a case report which documents multiple jaw cysts involving both the jaws, in three siblings of ages 10, 13 and 17 years with negative parental history. All three reported cases were free of any systemic involvement. As odontogenic keratocyst spreads through bone marrow, destruction is more before any clinical manifestation. Therefore, early detection and intervention are essential in preventing extensive destruction. PMID:23505078

Nirwan, Amit; Wanjari, Sangeeta Panjab; Saikhedkar, Rashmi; Karun, Vinayak

2013-01-01

68

Immunohistochemical analysis of P53 protein in odontogenic cysts  

PubMed Central

The p53 is a well-known tumor suppressor gene, the mutations of which are closely related to the decreased differentiation of cells. Findings of studies on immunohistochemical P53 expression in odontogenic cysts are controversial. The present study was carried-out to investigate the immunohistochemical expression of P53 protein in odontogenic cysts. Thirty paraffin blocks of diagnosed odontogenic cysts were processed to determine the immunohistochemical expression of P53 protein. Nine of the 11 odontogenic keratocysts (81.8%) expressed P53, one of three dentigerous cyst cases expressed P53, while none of the 16 radicular cysts expressed P53 protein. The findings of the present work supported the reclassification of OKC as keratocystic odontogenic tumor. PMID:23960493

Gaballah, Essam Taher M.A.; Tawfik, Mohamed A.

2010-01-01

69

Activation of anaerobic metabolism in Biomphalaria glabrata (Mollusca: Gastropoda) experimentally infected by Angiostrongylus cantonensis (Nematoda, Metastrongylidae) by high-performance liquid chromatography.  

PubMed

The activity of lactate dehydrogenase and the concentrations of glucose in the hemolymph and of glycogen in the digestive gland and cephalopedal mass of Biomphalaria glabrata experimentally infected with Angiostrongylus cantonensis were evaluated. Additionally, high performance liquid chromatography (HPLC) was used to determine the hemolymph concentrations of some carboxylic acids (oxalic, piruvic, lactic and succinic). After one, two and three weeks of infection, the snails were dissected to collect the hemolymph and separate the tissues. A significant reduction of the levels of glucose in the hemolymph was observed as of the first week of infection in relation to the control group. The lactate dehydrogenase activity of the infected group was significantly higher than the average of the control group. This increase was accompanied by a reduction of the levels of piruvic acid and an increase in the levels of lactic acid in the hemolymph of the parasited snails, confirming the acceleration of the anaerobic metabolism, necessary for the host to obtain energy and maintain its redox balance. In parallel, there was a decrease in the glycogen content of the storage tissues, with that reduction being significantly greater in the cephalopedal mass than the digestive gland, demonstrating that in this interaction system, the mobilization of glycogen was not sufficient to maintain and reestablish the normal glycemia of the infected snails. PMID:24042059

Tunholi-Alves, Vinícius Menezes; Tunholi, Victor Menezes; Castro, Rosane N; Sant'Ana, Luiza D'Oliveira; Santos-Amaral, Luciana; de Oliveira, Ana Paula Martins; Garcia, Juberlan; Thiengo, Silvana Carvalho; Pinheiro, Jairo; Maldonado, Arnaldo

2014-02-01

70

Evaluation of stromal myofibroblasts expression in keratocystic odontogenic tumor and orthokeratinized odontogenic cysts: A comparative study  

PubMed Central

Objective: Keratocystic odontogenic tumor (KCOT) has an aggressive clinical course and a high tendency of recurrence, while orthokeratinized odontogenic cyst (OOC) has different characteristics and does not show aggressive behaviour. Even the treatment of these two lesions varies considerably. A large number of epithelial molecules have been studied in order to differentiate odontogenic keratocyst (OKC) from OOC, but stromal factors have not been adequately studied. Recently, tumor stroma has evolved as a particular field of interest. In the present study, we aim to evaluate and compare the expression of stromal myofibroblasts (MFs) in these entities and correlate it to its aggressive behavior. The term ‘keratocystic odontogenic tumor’ has been introduced by WHO in 2005 for odontogenic keratocyst keeping in mind its aggressive behavior, however still many pathologists and clinicians use the term OKC synonymously. Materials and Methods: A total of 10 cases of KCOT and 10 cases of OOC were stained for alpha-smooth muscle actin (?SMA) for demonstration of stromal MFs. MF frequency was assessed as the number of ?SMA-positive stromal cells in 10 high power fields, presented as the mean number of positive cells per field. Results: Counts showed that the mean number of positive cells in KCOT (20.6 ± 2.05) was significantly higher than that seen in OOC (10.4 ± 1.06) (P < 0.05). Conclusion: The different behaviors of these lesions are compatible with the finding of the present study. The increased number of stromal MFs in KCOT in comparison to OOC correlates with its aggressive behavior and increased tendency towards recurrence. PMID:24250080

Roy, Swati; Garg, Vipul

2013-01-01

71

Aerobic to anaerobic transition in Biomphalaria glabrata (Say, 1818) infected with different miracidial doses of Echinostoma paraensei (Lie and Basch, 1967) by high-performance liquid chromatography.  

PubMed

The glucose content in the hemolymph and glycogen content in the digestive gland-gonad complex (DGG) and cephalopedal mass of Biomphalaria glabrata exposed to different parasite doses (5 and 50 miracidia) of Echinostoma paraensei as well as the activity of lactate dehydrogenase were evaluated. HPLC (high-performance liquid chromatography) analyses were also performed to determine the concentrations of four organic acids (oxalic, succinic, pyruvic and lactic) present in the hemolymph of infected and uninfected snails, to better understand the effect of infection on the host's energetic/oxidative metabolism. The snails were dissected 1-4 weeks after infection to collect the hemolymph and separate the tissues. There was alteration in the glycemia of the snails at both parasite doses, with a significant increase of glycemia from of the third week after infection in comparison to the control group. Changes were also observed in the lactate dehydrogenase activity, with increased activity as the infection progressed. In parallel, there was a decrease in the glycogen content in the storage tissues, with a markedly greater reduction in the digestive gland-gonad complex (larval development site) in comparison with the cephalopedal mass. Additionally, the infection by both miracidial doses resulted in an increase of oxalic and lactic acid levels, as well as in a decline of piruvic and succinic acid levels in B. glabrata, thus explaining the reduction of the oxidative decarboxylation rate in the tricarboxylic acid cycle and acceleration of the anaerobic degradation of carbohydrates in the snails, through lactic fermentation, which is essential to ensure energy supply and success of the infection. PMID:23376444

Tunholi, Victor Menezes; Tunholi-Alves, Vinícius Menezes; Lustrino, Danilo; Castro, Rosane N; Sant'Ana, Luiza D'Oliveira; Garcia, Juberlan Silva; Maldonado, Arnaldo; dos Santos, Marcos Antônio José; de Lurdes de Azevedo Rodrigues, Maria; Pinheiro, Jairo

2013-04-01

72

Odontogenic keratocysts: a study of 50 patients.  

PubMed

The odontogenic keratocyst (OKC) is a locally aggressive neoplasm with rates of recurrence reported as high as 60%. Correlation between histopathology and the likelihood of recurrence remains a subject of controversy. In this review of the authors' experience in treating 50 patients with OKC between 1977 and 1993, 58 specimens were studied to correlate the likelihood of recurrence with the presence of the following histologic features--parakeratosis, orthokeratosis, satellite cysts, epithelial rests, or epithelial proliferation. Orthokeratinized cysts were associated with a higher recurrence rate than in previously reported studies. Disruption of the epithelial lining in the resected specimen was found to be a primary determinant of recurrence. PMID:7530797

Anand, V K; Arrowood, J P; Krolls, S O

1995-01-01

73

Orthokeratinized Odontogenic Cyst of the Mandible with Heterotopic Cartilage  

PubMed Central

Cartilaginous metaplasia is a rare but well-documented phenomenon occurring in the wall of odontogenic keratocyst. The mural cartilage not associated with odontogenic keratocyst has been reported only once in a maxillary teratoid cyst of congenital origin to our knowledge. A case presented is a 38-year-old man with intraosseous keratinizing epidermoid cyst in the mandible, the wall of which contained a nodule of mature hyaline cartilage. The present lesion likely represents a previously undescribed, histologic hybrid consisting of orthokeratinized odontogenic cyst and cartilaginous heterotopia. PMID:19644543

Saito, Ichiro; Horie, Norio; Shimoyama, Tetsuo

2009-01-01

74

Orthokeratinized odontogenic cyst of the mandible with heterotopic cartilage.  

PubMed

Cartilaginous metaplasia is a rare but well-documented phenomenon occurring in the wall of odontogenic keratocyst. The mural cartilage not associated with odontogenic keratocyst has been reported only once in a maxillary teratoid cyst of congenital origin to our knowledge. A case presented is a 38-year-old man with intraosseous keratinizing epidermoid cyst in the mandible, the wall of which contained a nodule of mature hyaline cartilage. The present lesion likely represents a previously undescribed, histologic hybrid consisting of orthokeratinized odontogenic cyst and cartilaginous heterotopia. PMID:19644543

Ide, Fumio; Saito, Ichiro; Horie, Norio; Shimoyama, Tetsuo

2009-06-01

75

[Rapid preliminary diagnosis of anaerobic bacterial infections. II. Investigation of the presence of volatile and non-volatile fatty acids (C1-C6) in pus, purulent fluids and dressing by application of gas chromatography].  

PubMed

Studies were performed in the years 1986-1990 and dealing with 405 clinical materials originating from infections within the abdominal cavity, maxilla, reproductive organ, post-operative wounds as well as dressings, extremities, blood, bile and other types of material and usefulness of analysis by gas chromatography of presence of lower fatty acids in materials for rapid and preliminary diagnostics with strictly anaerobic bacteria was confirmed. Presence in chromatograms of isobutyric, butyric isovaleric, valeric, isocaproic and caproic acid, and partly of propionic acid, is a good indication of infection with strictly anaerobic bacteria. Moreover, presence of succinic acid may suggest presence of anaerobic infection, similarly as presence in chromatograms of three or more various lower fatty acids. Rapid, approximative diagnosis of anaerobic bacteria by application of gas chromatography is worth of broader application. Investigation of clinical material by this method lasts only 1-2 hours and obtained results my present a basis for preliminary diagnosis of the etiological factor and for direction of chemotherapy, which is very important in most early period of treatment of infections. PMID:1297037

Ka?owski, M; Dybicki, J; Korzon, T; Goebel, A; Kedzia, A; Kwapisz, E; Oppeln-Bronikowski, W; Czyz, W; Lukia?ski, M; Kopicki, T

1992-01-01

76

Bilateral orthokeratinized odontogenic cyst: A rare case report and review.  

PubMed

Orthokeratinized odontogenic cyst (OOC) is a developmental cyst of jaw and was initially considered by the World Health Organization (1992) as the uncommon orthokeratinized variant of odontogenic keratocyst (OKC). However, studies have shown that OOC has peculiar clinicopathologic aspects when compared with other developmental odontogenic cysts, especially OKC. So orthokeratinized odontogenic cyst now stands out to be a distinct entity. Clinically, it occurs as a single cyst, shows a predilection for males and is most often found in the second to the fifth decade. Its bilateral occurrence is extremely rare. The purpose of the article is to present a rare case of bilateral OOC arising in the mandible and review the literature on bilateral occurrence of this lesion. PMID:25328309

Pimpalkar, Rahul Devidas; Barpande, Suresh R; Bhavthankar, Jyoti D; Mandale, Mandakini S

2014-05-01

77

Bilateral orthokeratinized odontogenic cyst: A rare case report and review  

PubMed Central

Orthokeratinized odontogenic cyst (OOC) is a developmental cyst of jaw and was initially considered by the World Health Organization (1992) as the uncommon orthokeratinized variant of odontogenic keratocyst (OKC). However, studies have shown that OOC has peculiar clinicopathologic aspects when compared with other developmental odontogenic cysts, especially OKC. So orthokeratinized odontogenic cyst now stands out to be a distinct entity. Clinically, it occurs as a single cyst, shows a predilection for males and is most often found in the second to the fifth decade. Its bilateral occurrence is extremely rare. The purpose of the article is to present a rare case of bilateral OOC arising in the mandible and review the literature on bilateral occurrence of this lesion. PMID:25328309

Pimpalkar, Rahul Devidas; Barpande, Suresh R; Bhavthankar, Jyoti D; Mandale, Mandakini S

2014-01-01

78

Bilateral keratocystic odontogenic tumor: A report of two cases  

PubMed Central

The designation “keratocyst” was used to describe any jaw cyst in which keratin was formed to a large extent. A rare incidence of bilateral mandibular cysts (odontogenic keratocysts) was related to third molar teeth. Herein, we report two cases of bilateral keratocystic odontogenic tumor in a 22-year-old male and 15-year-old female, which was diagnosed by a series of investigations and treated appropriately. PMID:25298727

Srivatsan, K. S.; Kumar, Vikas; Mahendra, Ashish; Singh, Preeti

2014-01-01

79

Primary intraosseous squamous cell carcinoma of the maxilla possibly arising from an infected residual cyst: A case report  

PubMed Central

Primary intraosseous squamous cell carcinoma (PIOSCC) is a rare type of odontogenic carcinoma arising from the jawbone. Odontogenic cysts are true cysts that arise from the dental epithelium, which is associated with tooth formation. The epithelial lining of odontogenic cysts has the potential to transform into various types of odontogenic tumor; however, this transformation from an odontogenic cyst to a malignant tumor is rare. The definitive diagnosis for PIOSCC generally requires the observation of either features of squamous cell carcinoma (SCC) within the jawbone that are distinct from direct invasion from the surface oral epithelium, or evidence of SCC arising from odontogenic epithelium and from tumors that have metastasized to the jawbone from distant sites. In the present study, a case of PIOSCC of the maxilla is presented, which, based on the results of computed tomography and the clinical course, was hypothesized to have originated from an infected residual cyst.

SUKEGAWA, SHINTARO; MATSUZAKI, HIDENOBU; KATASE, NAOKI; KANNO, TAKAHIRO; MANDAI, TOSHIKO; TAKAHASHI, YUKA; ASAUMI, JUN-ICHI; FURUKI, YOSHIHIKO

2015-01-01

80

[Anaerobic paraproctitis].  

PubMed

An analysis of 25 cases of anaerobic paraproctitis has shown that in most cases they were people over 60 having severe concomitant diseases. Primary necrotic proctitis should be distinguished as a special morphological form. Sepsis was found to develop mostly in necrotic forms and ascending anaerobic lymphadenitis. An urgent wide opening of paraproctitis with a radical dissection of the tissues suspected of a damage is thought to be a necessary condition for the favourable outcome of the disease. PMID:6326371

Dolidze, N G; Kakoishvili, G A; Gvasaliia, G N

1984-03-01

81

Odontogenic ghost cell carcinoma: A case report with reference to the relation between apoptosis and ghost cells  

Microsoft Academic Search

The neoplastic variant of calcifying odontogenic cyst has various designations, and its malignant counterpart has been reported as aggressive epithelial odontogenic ghost cell tumor or odontogenic ghost cell carcinoma. We present a case of odontogenic ghost cell carcinoma with reference to the relation between the ghost cells and apoptosis. A 33-year-old man complained of a mandibular mass. The mass occupied

Jin Kim; Eun H Lee; Jong I Yook; Jee Y Han; Jung H Yoon; Gary L Ellis

2000-01-01

82

Development and evolutionary origins of vertebrate skeletogenic and odontogenic tissues.  

PubMed

This review deals with the following seven aspects of vertebrate skeletogenic and odontogenic tissues. 1. The evolutionary sequence in which the tissues appeared amongst the lower craniate taxa. 2. The topographic association between skeletal (cartilage, bone) and dental (dentine, cement, enamel) tissues in the oldest vertebrates of each major taxon. 3. The separate developmental origin of the exo- and endoskeletons. 4. The neural-crest origin of cranial skeletogenic and odontogenic tissues in extant vertebrates. 5. The neural-crest origin of trunk dermal skeletogenic and odontogenic tissues in extant vertebrates. 6. The developmental processes that control differentiation of skeletogenic and odontogenic tissues in extant vertebrates. 7. Maintenance of developmental interactions regulating skeletogenic/odontogenic differentiation across vertebrate taxa. We derive twelve postulates, eight relating to the earliest vertebrate skeletogenic and odontogenic tissues and four relating to the development of these tissues in extant vertebrates and extrapolate the developmental data back to the evolutionary origin of vertebrate skeletogenic and odontogenic tissues. The conclusions that we draw from this analysis are as follows. 8. The dermal exoskeleton of thelodonts, heterostracans and osteostracans consisted of dentine, attachment tissue (cement or bone), and bone. 9. Cartilage (unmineralized) can be inferred to have been present in heterostracans and osteostracans, and globular mineralized cartilage was present in Eriptychius, an early Middle Ordovician vertebrate unassigned to any established group, but assumed to be a stem agnathan. 10. Enamel and possibly also enameloid was present in some early agnathans of uncertain affinities. The majority of dentine tubercles were bare. 11. The contemporaneous appearance of cellular and acellular bone in heterostracans and osteostracans during the Ordovician provides no clue as to whether one is more primitive than the other. 12. We interpret aspidin as being developmentally related to the odontogenic attachment tissues, either closer to dentine or a form of cement, rather than as derived from bone. 13. Dentine is present in the stratigraphically oldest (Cambrian) assumed vertebrate fossils, at present some only included as Problematica, and is cladistically primitive, relative to bone. 14. The first vertebrate exoskeletal skeletogenic ability was expressed as denticles of dentine. 15. Dentine, the bone of attachment associated with dentine, the basal bone to which dermal denticles are fused and cartilage of the Ordovician agnathan dermal exoskeleton were all derived from the neural crest and not from mesoderm. Therefore the earliest vertebrate skeletogenic/odontogenic tissues were of neural-crest origin.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2205303

Smith, M M; Hall, B K

1990-08-01

83

Odontogenic Myxoma of Maxilla in an Atypical Location: A Case Report  

PubMed Central

Odontogenic myxoma is a rare and locally invasive benign neoplasm found exclusively in jaws. It presents local invasiveness and tendency to recurrence. According to the World Health Organization (WHO), the odontogenic myxoma is classified as an odontogenic tumor of ectomesenchymal origin. The odontogenic myxoma is a rare entity found in both jaws while the mandible is involved more commonly than the maxilla. We present a kind of odontogenic myxoma in a 24-year old male that was found in an unusual location. PMID:24724116

Ghalayani, P; Jahanshahi, GR; Mohagheghiyan, HR

2013-01-01

84

Orthokeratinized odontogenic cyst of the mandible: A rare case report with a systematic review  

PubMed Central

Orthokeratinized odontogenic cyst (OOC) is an odontogenic cyst was initially termed as the uncommon orthokeratinized type of odontogenic keratocyst by the World Health Organization. It usually occurs in mandible. Various studies have shown that OOC has typical characteristic clinicopathologic features when compared to other developmental odontogenic lesions such as dentigerous cyst and the keratocystic odontogenic tumor (KCOT). Rare recurrence was noted after surgical removal of the lesion. The purpose of this article is to present a case of OOC arising in the posterior mandible and emphasize on differentiating it from the KCOT and dentigerous cyst. PMID:24818100

Sarvaiya, Bhumi; Vadera, Hitesh; Sharma, Vimal; Bhad, Kaustubh; Patel, Zinal; Thakkar, Mimansa

2014-01-01

85

Orthokeratinized odontogenic cyst of the mandible: A rare case report with a systematic review.  

PubMed

Orthokeratinized odontogenic cyst (OOC) is an odontogenic cyst was initially termed as the uncommon orthokeratinized type of odontogenic keratocyst by the World Health Organization. It usually occurs in mandible. Various studies have shown that OOC has typical characteristic clinicopathologic features when compared to other developmental odontogenic lesions such as dentigerous cyst and the keratocystic odontogenic tumor (KCOT). Rare recurrence was noted after surgical removal of the lesion. The purpose of this article is to present a case of OOC arising in the posterior mandible and emphasize on differentiating it from the KCOT and dentigerous cyst. PMID:24818100

Sarvaiya, Bhumi; Vadera, Hitesh; Sharma, Vimal; Bhad, Kaustubh; Patel, Zinal; Thakkar, Mimansa

2014-01-01

86

[Anaerobic paraproctitis].  

PubMed

The authors had 80 patients, most of them (90%) of an old age, with anaerobic paraproctitis. Delayed hospitalization was encountered in 62 cases, in 16 of these cases an erroneous diagnosis had been established. Severe concomitant diseases complicated the course of anaerobic paraproctitis in 80% of cases (in each group of three patients one had diabetes mellitus). The authors describe characteristic clinical manifestations and the course of various forms of anaerobic paraproctitis, the results of bacteriological examination, and the order in which the surgical treatment is applied. They suggest a scheme of drug therapy which is maximally approximated to cleansing of a microbial cenosis, including ultraviolet irradiation of the blood. All these measures allowed the mortality rate to be decreased from 33.3% to 17.7%. PMID:7723255

Koplatadze, A M; Bondarev, Iu A; Egorkin, M A

1994-10-01

87

The diagnostic usefulness of immunohistochemistry for odontogenic lesions.  

PubMed

The diagnosis of odontogenic tumors can be challenging, largely due to their rarity and consequent difficulties in gaining experience in their assessment. In most cases, careful attention to morphology, in conjunction with clinical and radiological features will allow a diagnosis to be made. However, in some cases, immunohistochemical analysis of the tumor may be useful. In this review we will outline the immunohistochemical expression profile of normal developing odontogenic tissues and a range of odontogenic tumors. In many cases the immunohistochemical markers are neither specific nor sensitive enough to be of help in diagnosis, but in some cases such analysis may prove very useful. Thus we have outlined a limited number of circumstances where immunohistochemistry may be of use to the practicing diagnostic pathologist. PMID:25409846

Hunter, Keith D; Speight, Paul M

2014-12-01

88

Orthokeratinizing odontogenic cyst of maxilla with complex odontoma.  

PubMed

The orthokeratinized odontogenic cyst (OOC) and odontoma are the odontogenic cyst and tumor respectively that are minimally invasive neoplasms of head and neck region. OOC is a rare variant of odontogenic cyst characterized by the presence of excessive orthokeratin covering the cystic lining. Odontoma is a benign neoplasm/hamartoma often discovered accidently on panoramic radiographs. We came across a case of a 26-year-old male with swelling on his face along with difficulty in breathing. On the basis of radiographic and histopathological findings the final diagnosis of OOC associated with odontoma was given. However, there is no report in the English literature of the simultaneous occurrence of these two lesions and hence this case is very rare. It is unclear whether the two lesions were just coincidental or were actually related to each other. PMID:24574683

Kulkarni, Meena; Kheur, Supriya; Agrawal, Tripti; Ingle, Yashwant

2013-09-01

89

Orthokeratinizing odontogenic cyst of maxilla with complex odontoma  

PubMed Central

The orthokeratinized odontogenic cyst (OOC) and odontoma are the odontogenic cyst and tumor respectively that are minimally invasive neoplasms of head and neck region. OOC is a rare variant of odontogenic cyst characterized by the presence of excessive orthokeratin covering the cystic lining. Odontoma is a benign neoplasm/hamartoma often discovered accidently on panoramic radiographs. We came across a case of a 26-year-old male with swelling on his face along with difficulty in breathing. On the basis of radiographic and histopathological findings the final diagnosis of OOC associated with odontoma was given. However, there is no report in the English literature of the simultaneous occurrence of these two lesions and hence this case is very rare. It is unclear whether the two lesions were just coincidental or were actually related to each other. PMID:24574683

Kulkarni, Meena; Kheur, Supriya; Agrawal, Tripti; Ingle, Yashwant

2013-01-01

90

Are All Odontogenic Keratocysts Keratocystic Odontogenic Tumors? Correlation between Imaging Features and Epithelial Cell Proliferation  

PubMed Central

This study was to correlate and analyze the imaging features and epithelial cell proliferation pattern in different cases of keratocystic odontogenic tumors (KCOT) and study the role of inflammation using proliferative markers and different radiographic patterns of KCOT to determine its biological behavior. One hundred and eighty-six cases of KCOT were taken together and grouped based on radiographic patterns. Forty cases were randomly selected and stained using a proliferating cellular nuclear antigen marker. The correlation between imaging and epithelial proliferation with and without inflammation was determined. Unilocular variety is the most common type of KCOT, showing least epithelial proliferation of all the patterns. More than 50% of the multilocular KCOTs were associated with inflammation, showing an enhanced rate of epithelial proliferation. Results were subjected to statistical analysis. Different rates of epithelial proliferation of the different patterns suggested that all odontogenic keratocysts do not behave like tumors and that aggressive treatment should be reserved for selective cases only depending on radiographic and other histopathological parameters such as inflammation. PMID:23607070

Singh, Harkanwal Preet; Nayar, Amit; Raj, Asha; Kumar, Prince

2013-01-01

91

Scanning electron microscopy of odontogenic cyst epithelium.  

PubMed

The epithelial lining of 8 odontogenic keratocysts (OKC), 9 radicular (RC) and 3 dentigerous cysts (DC) were examined in SEM in order to study the ultrastructural surface topography of the lumenal surface cells. The orthokeratinized OKC showed a reticular network of intercommunicating microridges surrounding micropits giving a honeycombed appearance to the entire surface. The deep surface of these cells was covered by a complementary array of short stubby microvilli. This pattern was identical to that described for oral epithelium in areas of masticatory mucosa. The parakeratinized OKC showed a complex pattern of microplications (MP) on both upper and deep cell surfaces. The non-keratinized linings of RC and DC revealed a similar MP pattern but of a less complex nature. The MP pattern of cells from para- and non-keratinized cysts was identical to that described for oral epithelial cells from lining mucosa. The surface ultrastructure of ciliated, mucus and brush cells occurring in RC was found to be indistinguishable from that described in the mammalian respiratory tract. The MP pattern forms part of the cellular interdigitation mechanisms in stratified squamous epithelium. Differences in the ultrastructural configuration are related to the type of epithelium in terms of keratinization rather than to protective functions. PMID:1383303

Philipsen, H P; Chan, L S; Reichart, P A; Pang, M K

1992-05-01

92

KAI-1 protein expression in odontogenic cysts.  

PubMed

The KAI-1 tumor suppressor gene is widely distributed in normal tissues and its down-regulation may be correlated with the invasive phenotype and metastases in several different epithelial tumors. The aim of the present study was an evaluation of KAI-1 expression in radicular cysts (RC), follicular cysts (FC), orthokeratinized keratocysts (OOKC), and parakeratinized keratocysts (POKC). Eighty-five odontogenic cysts, 28 RC, 22 FC, and 35 OKC (16 OOKC, 19 POKC) were selected. All the POKC were negative and only four of 16 of the OOKC were positive for KAI-1. On the contrary, all RC and FC cases were positive and immunoreactivity for KAI-1 was detected throughout all the layers of the cyst epithelium. The lack of KAI-1 expression in POKC could help to explain the differences in the clinical and pathologic behavior of OKC and, according to what has been reported for epithelial tumors, could be related to the increased aggressive behavior and invasiveness of OKC. PMID:17320703

Iezzi, Giovanna; Piattelli, Adriano; Artese, Luciano; Goteri, Gaia; Fioroni, Massimiliano; Rubini, Corrado

2007-03-01

93

Orthokeratinized odontogenic cyst: a systematic review  

PubMed Central

Objectives The aims of the review were to evaluate the principal clinical and conventional radiographic features of orthokeratinized odontogenic cyst (OOC) by systematic review (SR), and to compare the frequency of OOC between four global groups. Methods The databases searched were the PubMed interface of MEDLINE and LILACS. Only those reports of OOCs that occurred in a consecutive series of OOCs in the reporting authors' caseload were considered. Results 37 reports on 36 case series were included in the SR. OOC affected males twice as frequently and the mandible almost 2.5 times as frequently. Although the mean age at first presentation was 35 years, the largest proportion of cases first presented in the third decade for the Western, East Asian and Latin American global groups. Seven reports included details of at least one clinical finding. 11 reported case series included at least 1 radiological feature. All OOCs were radiolucent, 93% were unilocular and 68% were associated with unerupted teeth. 28% of the reported case series included follow up. 4% of OCC recurred and all of these were in the Western global group. Conclusions Although one feature of OOCs is that they are unlikely to recur, some do. Not only is there a lack of long-term follow up of large series with long-term outcomes of OOC, but there is a paucity of clinical and radiological details of OOC at initial presentation. PMID:21062939

MacDonald-Jankowski, D S

2010-01-01

94

Anaerobic Metabolism 1 ANAEROBIC METABOLISM  

E-print Network

to aerobic metabolsm. This said, it is not uncommon to hear microbiologists talk about anaerobic respiration and respiration together since respiration historically implies breathing. Breathing, of course, is closely tied and if respiration is thought of as the catabolic pathways that yield ATP for other reactions, then this is certainly

Prestwich, Ken

95

Immunohistochemical Characteristics of Odontogenic Neoplasms and Their Physiological Counterparts  

Microsoft Academic Search

Development of the tooth is a complex and fascinating set of processes which require a sequential integration of numerous biological steps. For dental doctors, interest is particularly high, because the tooth is mainly composed of surface ectodermal epithelium and neural crest derived neuroectodermal mesenchyma, and formed by epithelial-mesenchymal interactions. There are many different types of odontogenic neoplasms. In general, proliferation,

Keisuke Nakano; Hitoshi Nagatsuka; Hidetsugu Tsujigiwa; Mehmet Gunduz; Naoki Katase; Chong Huat Siar; Toshiyuki Kawakami

2008-01-01

96

Orthokeratinized Odontogenic Cyst: A Report of Three Clinical Cases  

PubMed Central

The orthokeratinized odontogenic cyst (OOC) is a rare developmental odontogenic cyst that has been considered as a variant of the keratocystic odontogenic tumour (KCOT) until Wright (1981) defined it as a different entity. Surgery is the usual treatment, and recurrence or association with Gorlin-Goltz syndrome has rarely been described. In this report, we presented three cases of this pathology, and we review the principal clinical, histological, radiological, and therapeutic aspects. Case 1. A 73-year-old female presents with a slight swelling on the right mandible, associated with an unilocular well-defined radiolucent lesion. Case 2. A 27-year-old female presents with a painful mandibular swelling associated with an unilocular radiolucent lesion posterior to the 4.8. Case 3. A 61-year-old male was casually detected presents with an unilocular radiolucent lesion distal to the 4.8. Conclusion. The OOC is a specific odontogenic clinicopathological entity that should be differentiated from the KCOT as it presents a completely different biological behaviour. PMID:24191203

Gonzalez Galvan, Maria del Carmen; Garcia-Garcia, Abel; Anitua-Aldecoa, Eduardo; Martinez-Conde Llamosas, Rafael; Aguirre-Urizar, Jose Manuel

2013-01-01

97

Keratocyst of the buccal mucosa: is it odontogenic?  

PubMed

Odontogenic keratocyst (OKC) of the buccal mucosa, the diagnosis of which is based on subjective histologic evaluation, is a controversial entity of questionable existence. This report describes 2 rare cases of parakeratinized cyst arising from the buccal mucosa. Case 1 was a 60-year-old man with a 3-cm cyst and case 2 was a 16-year-old boy with a microcyst incidentally discovered on histology. Both lesions were essentially identical in histologic appearance and immunophenotype to intraosseous and gingival OKC, but they were clearly different from orthokeratinized odontogenic cysts and buccal mucosal epidermoid cysts. Step sections failed to reveal any kind of odontogenic tissue or skin adnexa in the cyst wall. These microscopic characteristics reflexively lead to the diagnosis of OKC, if the extragingival occurrence in the buccal mucosa cannot be considered. An alternative nonodontogenic origin includes a keratocyst of the skin, ie, an unusual mucosal presentation of cutaneous keratocyst. Because its true nature, either odontogenic or epidermal, cannot be conclusively proven at this time, we propose a more descriptive and noncommittal term, "mucosal keratocyst," for a particular cyst in a buccal location that is morphologically indistinguishable from OKC. PMID:20955942

Ide, Fumio; Kikuchi, Kentaro; Miyazaki, Yuji; Mishima, Kenji; Saito, Ichiro; Kusama, Kaoru

2010-11-01

98

Orthokeratinized odontogenic cyst: a report of three clinical cases.  

PubMed

The orthokeratinized odontogenic cyst (OOC) is a rare developmental odontogenic cyst that has been considered as a variant of the keratocystic odontogenic tumour (KCOT) until Wright (1981) defined it as a different entity. Surgery is the usual treatment, and recurrence or association with Gorlin-Goltz syndrome has rarely been described. In this report, we presented three cases of this pathology, and we review the principal clinical, histological, radiological, and therapeutic aspects. Case 1. A 73-year-old female presents with a slight swelling on the right mandible, associated with an unilocular well-defined radiolucent lesion. Case 2. A 27-year-old female presents with a painful mandibular swelling associated with an unilocular radiolucent lesion posterior to the 4.8. Case 3. A 61-year-old male was casually detected presents with an unilocular radiolucent lesion distal to the 4.8. Conclusion. The OOC is a specific odontogenic clinicopathological entity that should be differentiated from the KCOT as it presents a completely different biological behaviour. PMID:24191203

González Galván, María Del Carmen; García-García, Abel; Anitua-Aldecoa, Eduardo; Martinez-Conde Llamosas, Rafael; Aguirre-Urizar, José Manuel

2013-01-01

99

An intraosseous sclerosing odontogenic tumor predominantly composed of epithelial cells: relation to (so-called) sclerosing odontogenic carcinoma and epithelial-rich central odontogenic fibroma.  

PubMed

We report a case of an asymptomatic sclerosing odontogenic tumor in a 31-year-old woman. Radiologically, the tumor was well circumscribed, was predominantly radiolucent, and had a peripheral sclerotic margin. Histopathologically, the tumor showed small clusters, strands, and cords of small to medium-sized epithelial tumor cells in a sclerotic collagenous stroma. Immunohistochemically, the tumor cells were positive for broad-spectrum cytokeratins (CKs) (CK7, CK5/6, CK19, and CAM 5.2) and p63. Membranous staining for E-cadherin was present. There was weak to moderate nuclear expression of p16 in 30% of cells. Rare tumor cells were positive for p53. Progesterone receptors were expressed in about 60% of the tumor cells. The proliferative activity (Ki-67) was approximately 2%. A molecular genetic (fluorescence in situ hybridization) study showed no EWSR1 (EWS RNA-binding protein 1) gene rearrangement. No recurrence or metastatic events have been documented at 1-year follow-up. This tumor represents a classification dilemma mainly between epithelial-rich central odontogenic fibroma and the so-called sclerosing odontogenic carcinoma. PMID:24767700

Tan, Sze Hwa; Yeo, Jin Fei; Kheem Pang, Brendan Nghee; Petersson, Fredrik

2014-10-01

100

Squamous cell carcinoma in a maxillary odontogenic keratocyst: A rare entity  

PubMed Central

Odontogenic cysts in the maxilla are common but a malignant change in an odontogenic cyst is a comparatively a rare occurrence; however, these entities present with clinical and radiographic features similar to benign, expansible, central, odontogenic tumor, or cyst of the jaws. A patient reporting with squamous cell carcinoma arising from an odontogenic keratocyst of right maxilla has been worked up clinically, radiographically, and pathologically. The case was surgically managed and followed up. A 54-year-old male patient with a compressible, rapidly growing swelling of right maxilla was clinically diagnosed to be a case of odontogenic cyst. On radiologic examination it appeared similar to a cystic lesion. An incisional biopsy obtained from the cyst wall showed it to be odontogenic keratocyst with histologic evidence of malignant transformation. The pathogenesis of the tumor, the biologic progression, and prognosis and overall clinical and histopathogical features of this rare malignancy is reported and discussed. PMID:22639518

Maria, Anisha; Sharma, Yogesh; Chhabria, Amit

2011-01-01

101

Role of Heparanase in the Release of Heparan Sulphate Binding Growth Factors in Odontogenic Tumors  

Microsoft Academic Search

Immunolocalization of heparan sulphate(HS) and heparanase was evaluated in benign and malignant odontogenic tumors in order to know whether these molecules have potential roles in odontogenic tumorigenesis. Archival formalin-fixed, paraffin-embedded tissues of 6 human tooth germs, 7 adenomatoid odontogenic tumors, 10 ameloblastic fibromas, 20 ameloblastoma s and 4 ameloblastic carcinomas were subjected to immunohistochemical staining using antibodies to HS, heparanase

Phuu Pwint Han; Hitoshi Nagatsuka; Ryo Tamamura; Naoki Katase; Mathieu Bernard Lefeuvre; Hailong Hu; Shin Takagi; Nobuhisa Ishida; Keisuke Nakano; Toshiyuki Kawakami; Mehmet Gunduz

2007-01-01

102

The multifocal nature of odontogenic keratocysts.  

PubMed

The odontogenic keratocyst, OKC, is a very aggressive intraosseos lesion with a recurrence rate of approximately 25 percent to 60 percent.' The tendency for this lesion to "return" after surgical treatment has prompted studies to obtain more information concerning the inherent nature of the lesion. The OKC lesions are usually treated with enucleation of the soft tissue lining, curettage and ostectomy of the bony margins, or with more aggressive block resection. The purpose of this study was to characterize the multifocal aspect of the OKC and to demonstrate the presence of cystic lesions remote from the margins of the primarily diagnosed cyst itself. A retrospective chart review was conducted of seven patients who had sustained a long history of recurrent OKCs. Three types of documentation were reviewed for each patient: Orthopantomograms, cephalograms, and CT scans, which had been taken over the long-term course of the disease, Detailed operation reports of surgical procedures to treat the OKC lesions, and; Large histologic specimens from the six patients who received total resection of the involved mandibular bodies. These hemimandibulectomy slides offered a unique opportunity to observe OKC activity throughout a wide osseous area. All patients hod been operated multiple times over a period of 10 to 21 years, coming eventually to mandibular resection. The operating surgeon in all of the cases was one of the authors, Philip J. Boyne, DMD, MS, DSc. All patients exhibited the multifocal nature of OKCs with demonstrable cyst formation at distant sites in the mandible. Two patients had local recurrences at the margins of the primary lesion in addition to cyst formation at distant sites. The authors concluded that clinicians should respect the multifocal nature of OKCs. The "recurrences" observed in OKCs may not necessarily be due to the degree of skill of the surgeon or the technique used to eradicate the primary cyst, but instead are probably a reflection of the multifocal nature of the pathologic lesion itself. The OKC is a very aggressive intraosseos lesion of the jaws, which not infrequently clinicians detect in the process of routine oral examination. PMID:16454239

Boyne, Philip J; Hou, David; Moretta, Carlos; Pritchard, Tyler

2005-12-01

103

Adenomatoid odontogenic tumor - a report of two cases with histopathology correlation.  

PubMed

Adenomatoid odontogenic tumor (AOT) is an uncommon, hamartomatous, benign, epithelial lesion of odontogenic origin that was first described by Driebaldt in 1907, as a pseudo-adenoameloblastoma. The current World Health Organisation (WHO) classification of odontogenic tumors defines AOT as being composed of the odontogenic epithelium in a variety of histoarchitectural patterns, embedded in mature connective tissue stroma, and characterized by slow, but progressive growth. The current article reports two cases with different presentations; first in a young female patient and the second in a middle-aged male patient. The importance of biopsy, which is the gold standard for diagnosis, and its use in planning of the treatment is discussed. PMID:22347682

Baskaran, Pavitra; Misra, Satyaranjan; Kumar, M Sathya; Mithra, R

2011-01-01

104

Adenomatoid Odontogenic Tumor - A Report of Two Cases with Histopathology Correlation  

PubMed Central

Adenomatoid odontogenic tumor (AOT) is an uncommon, hamartomatous, benign, epithelial lesion of odontogenic origin that was first described by Driebaldt in 1907, as a pseudo-adenoameloblastoma. The current World Health Organisation (WHO) classification of odontogenic tumors defines AOT as being composed of the odontogenic epithelium in a variety of histoarchitectural patterns, embedded in mature connective tissue stroma, and characterized by slow, but progressive growth. The current article reports two cases with different presentations; first in a young female patient and the second in a middle-aged male patient. The importance of biopsy, which is the gold standard for diagnosis, and its use in planning of the treatment is discussed. PMID:22347682

Baskaran, Pavitra; Misra, Satyaranjan; Kumar, M. Sathya; Mithra, R.

2011-01-01

105

[Anaerobic paraproctitis].  

PubMed

Anaerobic paraproctitis (AP) was seen in 8.6% of 1057 cases with acute paraproctitis. Severe general condition of the patient, vast damage, fetid wound secretion, extensive detachment and necrosis of tissues were the main AP symptoms. Radical excision of affected tissues with daily revision and sanatation in combination with intensive general therapy permits to reduce mortality to 4.3%. In early postoperative period reversible insufficiency of anal sphincter developed in 16.1% AP patients. It is necessary to close wounds as early as possible. Perforated cutaneous pedicle flap from posterior wall of the scrotum may be successfully used for plastic repair of perineum wound. PMID:12418322

Trenin, S O; Gel'fenbe?n, L S; Shishkov, A V

2002-01-01

106

Carnoy's solution in the mangement of odontogenic keratocyst.  

PubMed

Carnoy's solution is a substance used as a complementary treatment after the conservative excision of odontogenic keratocyst. The application of Carnoy's solution promotes a superficial chemical necrosis and is intended to reduce recurrence rates. However, the inferior alveolar vascular-nervous plexus can occasionally be exposed after the removal of a lesion. The safety of the application of Carnoy's solution over this plexus has been reported, but to date, no clinical report has been made. The authors present a case that was given Carnoy's solution over the inferior alveolar vascular-nervous plexus as a complementary treatment for the keratocystic odontogenic tumor. Effective control of recurrence with low and transient neural morbidity was suggested with this technique. PMID:23066248

Sivanmalai, Sivaraj; Kandhasamy, Kohila; Prabu, Neetika; Prince, Christo Naveen; Prabu, Chandrakala Shekarappa Annapurna Pannaikadu Somasundaram

2012-08-01

107

Carnoy's solution in the mangement of odontogenic keratocyst  

PubMed Central

Carnoy's solution is a substance used as a complementary treatment after the conservative excision of odontogenic keratocyst. The application of Carnoy's solution promotes a superficial chemical necrosis and is intended to reduce recurrence rates. However, the inferior alveolar vascular–nervous plexus can occasionally be exposed after the removal of a lesion. The safety of the application of Carnoy's solution over this plexus has been reported, but to date, no clinical report has been made. The authors present a case that was given Carnoy's solution over the inferior alveolar vascular–nervous plexus as a complementary treatment for the keratocystic odontogenic tumor. Effective control of recurrence with low and transient neural morbidity was suggested with this technique. PMID:23066248

Sivanmalai, Sivaraj; Kandhasamy, Kohila; Prabu, Neetika; Prince, Christo Naveen; Prabu, Chandrakala Shekarappa Annapurna Pannaikadu Somasundaram

2012-01-01

108

Anaerobic thermophiles.  

PubMed

The term "extremophile" was introduced to describe any organism capable of living and growing under extreme conditions. With the further development of studies on microbial ecology and taxonomy, a variety of "extreme" environments have been found and an increasing number of extremophiles are being described. Extremophiles have also been investigated as far as regarding the search for life on other planets and even evaluating the hypothesis that life on Earth originally came from space. The first extreme environments to be largely investigated were those characterized by elevated temperatures. The naturally "hot environments" on Earth range from solar heated surface soils and water with temperatures up to 65 °C, subterranean sites such as oil reserves and terrestrial geothermal with temperatures ranging from slightly above ambient to above 100 °C, to submarine hydrothermal systems with temperatures exceeding 300 °C. There are also human-made environments with elevated temperatures such as compost piles, slag heaps, industrial processes and water heaters. Thermophilic anaerobic microorganisms have been known for a long time, but scientists have often resisted the belief that some organisms do not only survive at high temperatures, but actually thrive under those hot conditions. They are perhaps one of the most interesting varieties of extremophilic organisms. These microorganisms can thrive at temperatures over 50 °C and, based on their optimal temperature, anaerobic thermophiles can be subdivided into three main groups: thermophiles with an optimal temperature between 50 °C and 64 °C and a maximum at 70 °C, extreme thermophiles with an optimal temperature between 65 °C and 80 °C, and finally hyperthermophiles with an optimal temperature above 80 °C and a maximum above 90 °C. The finding of novel extremely thermophilic and hyperthermophilic anaerobic bacteria in recent years, and the fact that a large fraction of them belong to the Archaea has definitely made this area of investigation more exciting. Particularly fascinating are their structural and physiological features allowing them to withstand extremely selective environmental conditions. These properties are often due to specific biomolecules (DNA, lipids, enzymes, osmolites, etc.) that have been studied for years as novel sources for biotechnological applications. In some cases (DNA-polymerase, thermostable enzymes), the search and applications successful exceeded preliminary expectations, but certainly further exploitations are still needed. PMID:25370030

Canganella, Francesco; Wiegel, Juergen

2014-01-01

109

Anaerobic Thermophiles  

PubMed Central

The term “extremophile” was introduced to describe any organism capable of living and growing under extreme conditions. With the further development of studies on microbial ecology and taxonomy, a variety of “extreme” environments have been found and an increasing number of extremophiles are being described. Extremophiles have also been investigated as far as regarding the search for life on other planets and even evaluating the hypothesis that life on Earth originally came from space. The first extreme environments to be largely investigated were those characterized by elevated temperatures. The naturally “hot environments” on Earth range from solar heated surface soils and water with temperatures up to 65 °C, subterranean sites such as oil reserves and terrestrial geothermal with temperatures ranging from slightly above ambient to above 100 °C, to submarine hydrothermal systems with temperatures exceeding 300 °C. There are also human-made environments with elevated temperatures such as compost piles, slag heaps, industrial processes and water heaters. Thermophilic anaerobic microorganisms have been known for a long time, but scientists have often resisted the belief that some organisms do not only survive at high temperatures, but actually thrive under those hot conditions. They are perhaps one of the most interesting varieties of extremophilic organisms. These microorganisms can thrive at temperatures over 50 °C and, based on their optimal temperature, anaerobic thermophiles can be subdivided into three main groups: thermophiles with an optimal temperature between 50 °C and 64 °C and a maximum at 70 °C, extreme thermophiles with an optimal temperature between 65 °C and 80 °C, and finally hyperthermophiles with an optimal temperature above 80 °C and a maximum above 90 °C. The finding of novel extremely thermophilic and hyperthermophilic anaerobic bacteria in recent years, and the fact that a large fraction of them belong to the Archaea has definitely made this area of investigation more exciting. Particularly fascinating are their structural and physiological features allowing them to withstand extremely selective environmental conditions. These properties are often due to specific biomolecules (DNA, lipids, enzymes, osmolites, etc.) that have been studied for years as novel sources for biotechnological applications. In some cases (DNA-polymerase, thermostable enzymes), the search and applications successful exceeded preliminary expectations, but certainly further exploitations are still needed.

Canganella, Francesco; Wiegel, Juergen

2014-01-01

110

Clinicopathologic study of odontogenic keratocysts in Singapore and Malaysia.  

PubMed

This was a retrospective study of odontogenic keratocysts in people from the Singapore-Malaysian region. The purpose of this study was to present the clinicopathologic features of odontogenic keratocysts in the Oriental population and to compare these data with those from other reported studies. Biopsy records from 1981 to 1992 of 61 cases of odontogenic keratocysts from patients in Malaysia and Singapore showed that 42.6% of patients were female and 57.4% of patients were male. Among patients with cysts, 75.4% were Chinese, 6.6% were Malays, 9.8% were Indians and 8.2% were other ethnic groups. The mean age of these patients was 26.98 +/- 15.38 years with a peak incidence occurring in the second to fourth decades. The location of the lesions was more often in the mandible (65.5%) than the maxilla (31.0%). There was a marked predilection for lesions to occur in the posterior mandible. Histologically, 90.2% of the cysts were lined with a para-keratinized stratified squamous epithelium while only 3.3% of the cysts were lined with orthokeratinized stratified squamous epithelium. Mixed para-keratinized and orthokeratinized epithelial linings were observed in 4 cases (6.5%). The cyst linings were mainly uninflamed (95.1%). Inflammation of the cyst wall was found in 42 cases (68.8%). Twelve (19.7%) cases contained keratin in the lumen. A satellite cyst was observed in only 6 cases (9.8%). In conclusion, most clinical and histological features seen in this study were similar to those found for Caucasians. The only clinical feature that was different was the peak age incidence, that ranged from the second to fourth decades, with an absence of a second peak. Odontogenic keratocysts presenting at the site of the dentigerous cyst were observed in 7 cases (11.5%). PMID:10808269

Ngeow, W C; Zain, R B; Yeo, J F; Chai, W L

2000-03-01

111

Giant Keratocystic Odontogenic Tumor: Three Cases and Literature Review  

PubMed Central

Introduction: A keratocystic odontogenic tumor is a benign intra-bone mass originating from dental lamina or its residue. It represents 2–11% of jaw cysts, and has a slow but aggressive growth. The evaluation of molecular characteristics, immunohistochemistry, and genetic expression currently have no established classification regarding the evolution and pathophysiologic pattern of these lesions. Case Report: This is a clinical retrospective study with a full analysis of patient history regarding physical evaluation, radiologic images, pathology results, and surgical resection. We performed a major literature review concerning current concepts relating to its biological characterization. Three cases of keratocystic odontogenic tumor were identified. Two of the cases were large, with aggressive behavior and significant bone destruction and recurrence, which had been overlooked for more than a decade. The third case had an early diagnosis, and the treatment led to full recovery and complete healing. Conclusion: The keratocystic odontogenic tumor is a benign lesion with slow growth, which lends itself to a more conservative treatment, even in cases of large lesions. A better understanding of these tumors, both at the biological and molecular level, could lead to guidelines for treatment and prognosis of such patients. PMID:24303448

Caixeta Guimaraes, Alexandre; Dutra de Cassia Ferreira Santos, Mariana; Machado de Carvalho, Guilherme; Takahiro Chone, Carlos; Nizam Pfeilsticker, Leopoldo

2013-01-01

112

[Dental lamina as presumptive source of odontogenic cyst].  

PubMed

The possibility of the dental lamina as a source of odontogenic cyst was investigated. The mandibular first molar tooth germs with the dental lamina and surface oral epithelium were cut from 17.5-day-old C3H mouse embryos. The following 5 kinds of grafts were prepared: (I) recombinant of the dental lamina and dental papilla, (II) dental lamina, (III) dental papilla, (IV) recombinant of the oral epithelium and dental papilla and (V) oral epithelium. After the renal subcapsular transplantation to the 3-month-old syngenic male mice, each graft was harvested at timed sequences from 2 to 24 weeks and was examined histopathologically. The recombinant of the dental lamina and dental papilla (1) grew into a cyst lined by para-keratinized stratified squamous epithelium. The cyst enlarged gradually and might be compared to the odontogenic keratocyst of the human being. The recombinant of the oral epithelium and dental papilla (IV) and the oral epithelium (V) developed into a cyst lined by orthokeratinized stratified squamous epithelium which differed from the epithelium seen in Experiment (I). The dental papilla (III) grew to be a bone tissue while nothing developed from the dental lamina (II). These results suggest that the dental lamina is one of the sources of the odontogenic keratocyst and the dental papilla plays an important role in its histogenesis. PMID:2081936

Zhu, E

1990-12-01

113

Infections  

MedlinePLUS

... Externa) Eye Infections Pinkeye (Conjunctivitis) Styes Fungal Infections (Ringworm, Yeast, etc.) Diaper Rash Infections That Pets Carry Pneumocystis Pneumonia Tinea (Ringworm, Jock Itch, Athlete's Foot) Immunizations Flu Center ...

114

Linezolid Activity Compared to Those of Selected Macrolides and Other Agents against Aerobic and Anaerobic Pathogens Isolated from Soft Tissue Bite Infections in Humans  

Microsoft Academic Search

Linezolid was tested against 420 aerobes and anaerobes, including 148 Pasteurella isolates, by an agar dilution method. Linezolid was active against all Pasteurella multocida subsp. multocida and P. multocida subsp. septica isolates and most Pasteurella canis, Pasteurella dagmatis, and Pasteurella stomatis isolates. The MIC was <2 mg\\/ml for staphylococci, streptococci, EF-4b, Weeksella zoohelcum, Fusobacterium nucleatum, other fusobac- teria, Porphyromonas spp.,

ELLIE J. C. GOLDSTEIN; DIANE M. CITRON; C. VRENI MERRIAM

1999-01-01

115

Calcifying epithelial odontogenic tumor, a rare presentation in children: two case reports.  

PubMed

Calcifying epithelial odontogenic tumor (CEOT) is a rare and benign odontogenic neoplasm that affects the jaws. It is certainly an atypical instance to find this tumor in children. Here, we present two case reports of CEOT presenting in mandible of a 12- and 13-year-old female child, respectively. CEOT have been reported to show features of malignant transformation also. PMID:24739915

Mohanty, Susant; Mohanty, Neeta; Routray, Samapika; Misra, Satya Ranjan; Vasudevan, Vijeev

2014-01-01

116

Odontogenic tumors: A retrospective study of four Brazilian diagnostic pathology centers  

PubMed Central

Objective: This article presents the results of a retrospective study of the frequency and classification of odontogenic tumors recorded at four centers of diagnostic pathology in Rio de Janeiro, Brazil. Study Design: All medical records and microscopic slides of odontogenic tumor specimens for the years 1997 to 2007 were retrieved from the files of four services of diagnostic pathology in Rio de Janeiro City. Diagnoses were re-evaluated and the tumors classified according to the latest (2005) World Health Organization Classification of Tumors. Results: A total of 201 odontogenic tumors were found among 15,758 oral biopsies (1.3%). The frequencies of these tumors at the four centers ranged from 0.5% at the National Cancer Institute to 3.3% in a private laboratory. Chi-square analysis revealed statistically significant differences (p<0.05) between the proportions of odontogenic tumors in the studied centers. Of these, 94.5% were benign and 5.5% were malignant. Keratocystic odontogenic tumor (32.3%) was the most frequent lesion, followed by ameloblastoma (29.8%) and odontoma (18.4%). Conclusions: Odontogenic tumors are uncommon in Brazil. Different pathology laboratories reported divergent frequencies of odontogenic tumors, which may reflect institutional specializations and the patient populations served. Key words:Odontogenic tumors, jaw neoplasms, epidemiology, WHO classification. PMID:22143740

da-Costa, Daniela O P.; Mauricio, Almir S.; de-Faria, Paulo A S.; da-Silva, Licinio E.; Mosqueda-Taylor, Adalberto

2012-01-01

117

Evaluation of bax and bcl-2 expression in odontogenic keratocysts and orthokeratinized odontogenic cysts: A comparison of two cysts.  

PubMed

Odontogenic keratocyst (OKC) has an aggressive clinical course and a high tendency toward recurrence, while orthokeratinized odontogenic cyst has different characteristics and does not show aggressive behavior. Bax and bcl-2 are two important anti-apoptotic and pro-apoptotic factors of the bcl-2 family. The different outcomes of theses two cysts could be related to these apopto-proteins. Twenty-eight cases of OKC and nine cases of orthokeratinized odontogenic cyst (OOC) were stained for bax and bcl-2 proteins. Immunoreactivity for bcl-2 was detected in the basal layer of OKCs, while OOCs were completely negative in the basal layer (P<0.001). Bcl-2 expression in the whole thickness of OKCs was also significantly higher than in OOCs (P<0.001). Bax expression did not show any statistically significant difference between the two cysts (P=0.077). The different behaviors of these cysts are compatible with their immunohistochemical view. Lower expression of bcl-2 in OOC ends in less aggressiveness and a lower tendency toward recurrence. Bax seems to play no significant role by itself; however, the bcl-2/bax ratio is probably a determinant factor for different outcomes. PMID:19362040

Rangiani, A; Motahhary, P

2009-07-01

118

Study of the biologic behavior of odontogenic keratocyst and orthokeratinaized odontogenic cyst using TGF-alpha and P53 markers.  

PubMed

Odontogenic keratocyst (OKC) is an aggressive cyst, and its recurrence rate is higher than that of other odontogenic cysts. Orthokeratinized odontogenic cyst (OOC) is less aggressive than OKC, but bears the probability of carcinomatous changes. In this study, we evaluated the expression and intensity of P53 and TGF-alpha in order to compare the biologic behavior or probable carcinomatous changes of these two cysts. In this cross-sectional study, 15 OKC and 15 OOC were stained immunohistochemically for P53 and TGF-alpha using the Novolink polymer method. Then, all slides were examined by an optical microscope with 400× magnification, and the stained cells in the basal and parabasal layers were counted. Finally, the results were analyzed by the Mann-Whitney and Wilcoxon tests (P-value<0.05). The difference between the expression of P53 and TGF alpha in the basal layer of OKC and OOC was not statistically significant (P-value>0.05), but the expression of P53 and TGF-alpha in the parabasal layer in OKC was statistically higher compared to OOC (P<0.05). Considering the known role of P53 and TGF-alpha in malignant changes and the higher expression of P53 and TGF-alpha in OKC compared to those in OOC, the probability of carcinomatous changes was higher in OKC than in OOC. PMID:24462551

Deyhimi, Parviz; Hashemzadeh, Zahra

2014-04-01

119

Frequency of the odontogenic maxillary sinusitis extended to the anterior ethmoid sinus and response to surgical treatment  

PubMed Central

Objectives: Odontogenic sinusitis usually affects the maxillary sinus but may extend to the anterior ethmoid sinuses. The purpose of this study is to determine the percentage of odontogenic maxillary sinusitis extended to the anterior ethmoid sinuses and determine also the surgical resolution differences between odontogenic maxillary sinusitis and odontogenic maxillary associated to anterior ethmoidal sinusitis. Study Design: This is a retrospective cohort study performed on 55 patients diagnosed of odontogenic sinusitis and treated surgically by functional endoscopic sinus surgery. Results: This study showed that 52.7% of odontogenic maxillary sinusitis spreads to anterior ethmoid, causing added anterior ethmoid sinusitis. We found that 92.3% of the odontogenic maxillary sinusitis (who underwent middle meatal antrostomy) and 96.5% of the odontogenic maxillary sinusitis extended to the anterior ethmoid (treated with middle meatal antrostomy and anterior ethmoidectomy) were cured. Conclusions: Ethmoid involvement is frequent in maxillary odontogenic sinusitis. The ethmoid involvement does not worsen the results of “functional endoscopic sinus surgery” applied to the odontogenic sinusitis. Key words:Odontogenic maxillary sinusitis, ethmoiditis, functional endoscopic sinus surgery. PMID:24608208

Crovetto-Martinez, Rafael; Martin-Arregui, Francisco J.; Zabala-Lopez-de-Maturana, Aitor; Tudela-Cabello, Kiara

2014-01-01

120

LIFE-THREATENING ORO-FACIAL INFECTIONS  

Microsoft Academic Search

SUMMARY Four cases of oro-facial infection leading to life- threatening complications are reported. Although all had been treated with antibiotics prior to con- sultation, lack of surgical intervention had allowed the infection to progress. These cases are a re- minder that acute spreading odontogenic infection can be life-threatening. Definitive treatment in- cludes airway management, adequate resuscitation and optimization of pre-existing

E. K. AMPONSAH; P. DONKOR

121

Keratocystic odontogenic tumor: treatment modalities: study of 3 cases.  

PubMed

Management of the keratocystic odontogenic tumor has been one of the most controversial entities of the maxillofacial surgery. It can become quite large because of its ability for significant expansion, extension into adjacent tissues and rapid growth and also has high reccurence rate as it shows a thin, friable wall, which is often difficult to enucleate from the bone in toto, and have small satellite cysts within the fibrous wall. There are various treatment modalities suggested from conservative to radical approach, but studies have shown even with conservative approach good results are achieved. In this paper we are presenting various treatment modalities and 3 cases have been discussed. PMID:24714022

Roopak, B; Singh, M; Shah, A; Patel, G

2014-01-01

122

Scanning and transmission electron microscopy of odontogenic keratocysts.  

PubMed

The ultrastructural characteristics of the superficial cells of the epithelial lining of odontogenic keratocysts were studied. Examples of both the parakeratinized type and the less common orthokeratinized variant were examined. Scanning electron microscopy reveals that the morphology of the two cyst types is distinctly different. In parakeratinized cysts the transition of the epithelial cells into parakeratin is readily apparent and the epithelial surface is sparsely covered with parakeratin squames. In the orthokeratinized type the surface morphology is more uniform and is entirely covered with a leafy layer of keratin squames. The morphologic differences between the parakeratinized and orthokeratinized cysts may reflect differences in their biologic behavior. PMID:1058440

Wysocki, G P; Sapp, J P

1975-10-01

123

Comparative study of TGF-alpha and P53 markers' expression in odontogenic keratocyst and orthokeratinaized odontogenic cyst  

PubMed Central

Background: Odontogenic keratocyst (OKC) is an aggressive cyst and its recurrence is higher than other odontogenic cysts, orthokeratinized odontogenic cyst (OOC) is a cyst with moderate biological behavior in comparison with OKC, but with the probability of carcinomatous changes. The present study aims to evaluate the quantity and intensity of the expression of P53 protein and transforming growth factor alpha (TGF-alpha) in OKC and OOC in order to compare the biologic behavior of these two cysts. Materials and Methods: This is a cross-sectional study. The samples include 30 cysts (15 OKC and 15 OOC), all stained immunohistochemically for P53 protein and TGF-alpha by the Novolinke polymer method. Then, all the cases were examined with an optical microscope with ?400 magnification and the stained cells were counted in the basal and parabasal layers. Finally the results were analyzed by the Mann–and Wilcoxon tests (P value < 0.05). Results: The difference between the expression of P53 protein in the basal layer in OKC and OOC was not statistically significant (P value = 0.076). The difference between the expression of P53 protein in the parabasal layer in OKC and OOC was statistically significant (P value = 0.003); moreover, the difference between the expression of TGF-alpha in the basal layer in OKC and OOC was not statistically significant (P value = 0.284). The difference between the expression of TGF-alpha in the parabasal layer in OKC and OOC was statistically significant (P value = 0.015). Conclusion: Since there was a higher expression of P53 protein and TGF-alpha in OKC compared to those in OOC, the probability of carcinomatous changes was at least theoretically higher in OKC than in OOC. PMID:23814560

Deyhimi, Parviz; Hashemzade, Zahra

2012-01-01

124

Glandular odontogenic cyst in maxilla: A case report and literature review  

PubMed Central

Glandular odontogenic cyst (GOC) is an uncommon jaw bone cyst of odontogenic origin described in 1987 by Gardner et al. It is a cyst having an unpredictable and potentially aggressive behavior. The increased recurrence rate can be due to its multilocularity and incomplete removal of the lining following conservative treatment. Clinically, the most common site of occurrence is the anterior region of mandible. GOC has a slight male predilection and occurs primarily in middle-aged patients. This article presents a case of glandular odontogenic cyst in a 30-year-old female patient in the posterior region of the maxilla, which is quite rare.

Purohit, Sharad; Shah, Vandana; Bhakhar, Vikas; Harsh, Ashutosh

2014-01-01

125

Comparative in vitro susceptibilities of anaerobic bacteria to cefmenoxime, cefotetan, and N-formimidoyl thienamycin.  

PubMed Central

The in vitro activities of cefmenoxime, cefotetan, and N-formimidoyl thienamycin were compared with those of other antimicrobial agents (metronidazole, clindamycin, cefoxitin, and moxalactam) against anaerobic bacteria. The data obtained indicate that N-formimidoyl thienamycin exhibits excellent activity against anaerobic bacteria; cefotetan and cefmenoxime, though less active, should be of value in treating selected anaerobic infections. PMID:6305265

Owens, W E; Finegold, S M

1983-01-01

126

Surgical management of odontogenic myxoma: a case report and review of the literature  

PubMed Central

Background Odontogenic myxoma is a benign odontogenic tumor with locally aggressive behavior, and is relatively rare in the oral cavity. There are currently no clear surgical management guidelines for odontogenic myxoma, and a variety of approaches may be used. This study evaluated the literature concerning the surgical management of odontogenic myxoma, and reports the long-term outcome of a case managed by using a more conservative surgical approach. Case presentation We managed a 40-year-old Japanese man with odontogenic myxoma in the right mandible by enucleation and curettage, a relatively conservative approach that has proved to have been justified by a lack of recurrence over 10 years. Our strategy was compared with others reported in the literature, which was identified by a PubMed search using the term “odontogenic myxoma”. Articles without full text or with missing data were excluded. The age and sex of patients, the tumor location (maxilla/mandible), treatment (conservative/radical), recurrence, and follow-up period were compared in the reported cases that we evaluated. From the initial 211 studies identified, 20 studies qualified as mandibular cases of odontogenic myxoma. Recurrence was reported in three cases that had been treated with a more conservative surgical approach. Conclusions Enucleation and curettage has proved an effective approach in several cases in ours there has been no recurrence more than 10 years after surgery but the risk of recurrence appears to be higher. We discuss the important factors that must be considered when determining the correct management approach to odontogenic myxoma. PMID:24708884

2014-01-01

127

Immunohistochemical demonstration of an enamel sheath protein, sheathlin, in odontogenic tumors  

Microsoft Academic Search

Enamel proteins can be useful markers for assessment of the functional differentiation of neoplastic epithelium and the nature\\u000a of extracellular matrices in odontogenic tumors. In the present study, we examined immunohistochemical localization of sheathlin,\\u000a a recently cloned enamel sheath protein, in various odontogenic tumors to evaluate functional differentiation of tumor cells\\u000a and the nature of hyalinous or calcified matrices in

Takashi Takata; Ming Zhao; Takashi Uchida; Yasusei Kudo; Sunao Sato; Hiromasa Nikai

2000-01-01

128

Bimaxillary Keratocystic Odontogenic Tumour: A Case of Diagnostic and Therapeutic Difficulty  

PubMed Central

Keratocystic odontogenic tumour (KCOT) is a benign cystic intraosseous tumour of odontogenic origin that is usually solitary except when syndromic. It rarely occurs in the maxilla; therefore a rapidly progressive, nonsyndromic bimaxillary KCOT with locoregional extension poses significant diagnostic and management challenges. To the best of the authors' knowledge, documentation of a nonsyndromic bimaxillary KCOT is nonexistent in the English literature. We therefore present the case of an extensive bimaxillary KCOT in a 38-year-old Nigerian male. PMID:24790606

Okoje-Adesomoju, Victoria Nwebuni; Adisa, Akinyele Olumuyiwa; Gbolahan, Olalere Omoyosola; Olajide, Mofoluwaso Abimbola

2014-01-01

129

Calcifying ghost cell odontogenic cyst: A review on terminologies and classifications  

PubMed Central

Calcifying ghost cell odontogenic cyst (CGCOC) is a relatively uncommon odontogenic lesion characterized by varied clinical, radiographical features and biological behavior. CGCOC can exhibit either as a cystic or a solid lesion. Since its first description by Gorlin et al, in 1962, it has been known by different names and classified and sub-classified into various types. In this article we present a case of CGCOC and discuss the related literature regarding the terminology, classification and biological behavior of CGCOC. PMID:23248487

Thinakaran, Meera; Sivakumar, Palanivelu; Ramalingam, Sudhakar; Jeddy, Nadeem; Balaguhan, S.

2012-01-01

130

Immediate reconstruction of the mandible after resection for aggressive odontogenic tumours: a cohort study.  

PubMed

The results are reported of a clinical follow-up study on 32 selected but consecutive patients with mandibular ameloblastoma. They were all treated by a segmental resection and reconstructed, using two 2.3 mm reconstruction plates and an autogenous particulate bone graft, taken from the anterior iliac crest, and platelet rich plasma. Follow-up ranged from 12 to 39 months, with an average of 27.9 months. Undisturbed healing occurred in 29 patients, while three had postoperative infections, but in only one case did that result in failure of the graft. The patients' appreciation was measured using an adapted quality of life questionnaire. The results were compared with a similar group who did not undergo reconstruction. The eating of solid food, appearance and speech were considerably better in the reconstructed group. The conclusion is that this means of reconstruction is appropriate for patients with benign but aggressive odontogenic tumours of the mandible, particularly in developing countries, since the expenses seem to be affordable. PMID:22898314

Simon, E N M; Merkx, M A W; Kalyanyama, B M; Shubi, F M; Stoelinga, P J W

2013-01-01

131

Clinical review: Bacteremia caused by anaerobic bacteria in children  

PubMed Central

This review describes the microbiology, diagnosis and management of bacteremia caused by anaerobic bacteria in children. Bacteroides fragilis, Peptostreptococcus sp., Clostridium sp., and Fusobacterium sp. were the most common clinically significant anaerobic isolates. The strains of anaerobic organisms found depended, to a large extent, on the portal of entry and the underlying disease. Predisposing conditions include: malignant neoplasms, immunodeficiencies, chronic renal insufficiency, decubitus ulcers, perforation of viscus and appendicitis, and neonatal age. Organisms identical to those causing anaerobic bacteremia can often be recovered from other infected sites that may have served as a source of persistent bacteremia. When anaerobes resistant to penicillin are suspected or isolated, antimicrobial drugs such as clindamycin, chloramphenicol, metronidazole, cefoxitin, a carbapenem, or the combination of a beta-lactamase inhibitor and a penicillin should be administered. The early recognition of anaerobic bacteremia and administration of appropriate antimicrobial and surgical therapy play a significant role in preventing mortality and morbidity in pediatric patients. PMID:12133179

Brook, Itzhak

2002-01-01

132

Evaluation of Calretinin expression in Ameloblastoma and Non-Neoplastic Odontogenic Cysts - An immunohistochemical study  

PubMed Central

Background: Calretinin a 29-kDa calcium binding protein is expressed widely in normal human tissue and tumours including amelobastoma. The objective of this study was to determine calretinin expression in heamatoxylin and eosin diagnosed cases of ameloblastoma and non-neoplastic odontogenic cysts. Materials & Methods: The lining epithelium in 3 cases of radicular cysts, 5 cases of odontogenic keratocysts, 5 cases of dentigerous cysts and 11 cases of ameloblastomas were examined for expression of calretinin. Results: No positive epithelial staining was observed in radicular and dentigerous cysts. In comparison, however 100% of cases of ameloblastomas and 40% of cases of odontogenic karatocysts showed positive calretinin expression. Conclusion: Calretinin may be a specific immunohistochemical marker for ameloblastoma. If there is any possible relation between calretinin expression and neural origin of the odontogenic epithelium and its neoplastic transformation and if calretinin could be used as an early marker to predict the tendency of neoplastic change of odontogenic epithelium could be answered through further researches. How to cite this article: D’Silva S, Sumathi MK, Balaji N, Shetty NK, Pramod KM, Cheeramelil J. Evaluation of Calretinin expression in Ameloblastoma and Non-Neoplastic Odontogenic Cysts – An immunohistochemical study. J Int Oral Health 2013; 5(6):42-8 . PMID:24453443

D'Silva, Shaloom; Sumathi, M K; Balaji, N; Shetty, Nisha K N; Pramod, K M; Cheeramelil, Jacob

2013-01-01

133

Endocarditis due to Anaerobic Bacteria  

Microsoft Academic Search

This review describes the microbiology, diagnosis and management of endocarditis due to anaerobic bacteria. Anaerobic bacteria are an uncommon but important cause of endocarditis. Most cases of anaerobic endocarditis are caused by anaerobic cocci, Propionibacterium acnes and Bacteroides fragilis group. Predisposing factors and signs and symptoms of endocarditis caused by anaerobic bacteria are similar to those seen in endocarditis with

Itzhak Brook

2002-01-01

134

Surgical treatment of keratocystic odontogenic tumour: A review article.  

PubMed

KCOT is one of the most aggressive odontogenic cysts with a high recurrence rate, this was explained histopathologically as it typically shows a thin, friable wall, which is often difficult to enucleate from the bone in one piece, and have small satellite cysts within the fibrous wall. Multiple surgical approaches were introduced including decompression, marsupilization, enucleation with or without adjunct (Carnoy's solution, enucleation) and resection. Depending on other studies KCOT can be conservatively treated with enucleation and application of Carnoy's solution or cryotherapy. This can be used specially in the large lesions that when treated with resection, the continuity of the jaw will be interrupted. This technique shows comparable results to other more aggressive techniques. PMID:24151416

Abdullah, Walid Ahmed

2011-04-01

135

Odontogenic differentiation of vascular endothelial growth factor-transfected human dental pulp stem cells in vitro.  

PubMed

Dental pulp stem cells (DPSCs) can be induced towards odontogenic differentiation. Previous studies have shown that vascular endothelial growth factor (VEGF) is able to induce the osteogenic differentiation of cells, but the effectiveness of VEGF in the odontogenic differentiation of DPSCs remains unclear. This study aimed to investigate the effects of lentivirus?mediated human VEGF gene transfection on the proliferation and odontogenic differentiation of human DPSCs in vitro. DPSCs were transfected with either lentiviral pCDH?CMV?MCS?EFI?copGFP (pCDH) vector or recombinant pCDH?VEGF vector, and the growth characteristics of the resulting DPSCs/Vector and DPSCs/VEGF were subsequently assessed. The odontogenic differentiation genes of the two groups of cells, including alkaline phosphatase, osteocalcin, dentin sialophosphoprotein and dentin matrix protein 1 (DMP1), were evaluated by quantitative polymerase chain reaction (qPCR). The specific proteins of odontogenic differentiation, including dentin sialoprotein and DMP1, were analyzed by western blotting. DPSCs/VEGF showed similar proliferation characteristics to DPSCs/Vector during the observation period. qPCR results showed that the relative VEGF gene expression was significantly higher in DPSCs/VEGF than that in DPSCs/Vector two days after transfection (P<0.01). Similarly, western blot analysis showed that the protein expression levels of VEGF were higher in DPSCs/VEGF than those in DPSCs/Vector. On the first, fourth, eighth and 16th days after lentivirus-mediated transfection, the expression of odontogenic differentiation-specific genes and proteins was higher in DPSCs/VEGF than that in DPSCs/Vector. These results indicated that lentivirus-mediated VEGF gene transfection promoted the odontogenic differentiation of human DPSCs in vitro. PMID:25119396

Zhang, Wen; Liu, Wei; Ling, Junqi; Lin, Zhengmei; Gao, Yan; Mao, Xueli; Jian, Yutao

2014-10-01

136

Developmental Odontogenic Cysts of Jaws: A Clinical Study of 245 Cases  

PubMed Central

Background and aims The aim of this study was to investigate the relative frequency of developmental odontogenic cysts in an Iranian population. Materials and methods In this study 245 cysts from both jaws, treated in the Faculty of Dentistry at Tabriz University of Medical Sciences during a 10-year period from 1998 to 2008, were analyzed in order to evaluate the incidence of such cysts. We had permission from all the patients. Case histories of 65% of male and 35% of female patients were analyzed. The age of the patients varied from 14 to 64 years, with an average of 33.21 ± 10.89. Results In this 10-year study of odontogenic cysts, 97 cases were developmental odontogenic cysts with the following inci-dence: dentigerous cyst, 44%; odontogenic keratocyst, 36%; primordial cyst, 9%; Gorlin cyst, 2%; lateral periodontal cyst, 3%; eruption cyst, 3%; and gingival cyst, 3% (adults 2%, infants 1%). A total of 60% of the cysts were found in the mandible and 40% in the maxilla. Regarding the mandible, the molar region was involved in 47% of the cases, premolar region in 33% and anterior region in 20% (total = 100%). Regarding the maxilla, the canine-to-canine region was involved in 52% of the cases, premolar region in 20% and molar region in 28% (total = 100%). Conclusion An important finding in this study was the fact that 39% of the jaw cysts were developmental odontogenic cysts and the most common developmental odontogenic cysts were dentigerous cyst and OKC (odontogenic keratocyst). PMID:23230485

Yazdani, Javad; Kahnamouii, Shiva Solahaye

2009-01-01

137

KDM6B epigenetically regulates odontogenic differentiation of dental mesenchymal stem cells.  

PubMed

Mesenchymal stem cells (MSCs) have been identified and isolated from dental tissues, including stem cells from apical papilla, which demonstrated the ability to differentiate into dentin-forming odontoblasts. The histone demethylase KDM6B (also known as JMJD3) was shown to play a key role in promoting osteogenic commitment by removing epigenetic marks H3K27me3 from the promoters of osteogenic genes. Whether KDM6B is involved in odontogenic differentiation of dental MSCs, however, is not known. Here, we explored the role of KDM6B in dental MSC fate determination into the odontogenic lineage. Using shRNA-expressing lentivirus, we performed KDM6B knockdown in dental MSCs and observed that KDM6B depletion leads to a significant reduction in alkaline phosphate (ALP) activity and in formation of mineralized nodules assessed by Alizarin Red staining. Additionally, mRNA expression of odontogenic marker gene SP7 (osterix, OSX), as well as extracellular matrix genes BGLAP (osteoclacin, OCN) and SPP1 (osteopontin, OPN), was suppressed by KDM6B depletion. When KDM6B was overexpressed in KDM6B-knockdown MSCs, odontogenic differentiation was restored, further confirming the facilitating role of KDM6B in odontogenic commitment. Mechanistically, KDM6B was recruited to bone morphogenic protein 2 (BMP2) promoters and the subsequent removal of silencing H3K27me3 marks led to the activation of this odontogenic master transcription gene. Taken together, our results demonstrated the critical role of a histone demethylase in the epigenetic regulation of odontogenic differentiation of dental MSCs. KDM6B may present as a potential therapeutic target in the regeneration of tooth structures and the repair of craniofacial defects. PMID:24158144

Xu, Juan; Yu, Bo; Hong, Christine; Wang, Cun-Yu

2013-12-01

138

Anaerobic thermophilic culture  

DOEpatents

A newly discovered thermophilic anaerobe is described that was isolated in a biologically pure culture and designated Thermoanaerobacter ethanolicus ATCC 3/550. T. Ethanolicus is cultured in aqueous nutrient medium under anaerobic, thermophilic conditions and is used in a novel process for producing ethanol by subjecting carbohydrates, particularly the saccharides, to fermentation action of the new microorganism in a biologically pure culture.

Ljungdahl, Lars G. (Athens, GA); Wiegel, Jurgen K. W. (Gottingen, DE)

1981-01-01

139

Infection!  

NSDL National Science Digital Library

Play Infection! the game where you're the germ. And while you play, learn about the way your body fights infections.The game works best in Netscape 4 and Internet Explorer 4 or later. You will need to download Shockwave, but don't worry, you can do that right from the site.

York, Amercian M.

140

Anaerobic bacteremia in patients with acute leukemia.  

PubMed

We reviewed 402 hospital admissions of patients with acute leukemia to define the frequency and characteristics of anaerobic bacteremia in this patient population. Six (5.2%) of the 116 septicemia episodes documented in these patients were caused by anaerobes (Bacteroides species, 3; Fusobacterium species, 2; and Clostridium tertium, 1); two of these episodes were polymicrobial. Five patients had had prior bacteremia. All six patients were receiving broad-spectrum antibiotics, including an anti-pseudomonal penicillin, at the time of the episode. In each instance, the absolute granulocyte count was 0/mm3. Five patients had clinically apparent sources of infection, including perirectal abscess, gastrointestinal bleeding, or Clostridium difficile-associated diarrhea. Anaerobic bacteremia is an infrequent occurrence in granulocytopenic patients with acute leukemia, but may occur when there is obvious disruption of normal gastrointestinal anatomic barriers. PMID:2647821

Brown, E A; Talbot, G H; Provencher, M; Cassileth, P

1989-02-01

141

The effect of scaffold architecture on odontogenic differentiation of human dental pulp stem cells  

PubMed Central

Previous studies have shown the superiority of nanofibrous (NF) poly(L-lactic acid) (PLLA) scaffolds in supporting the osteogenic differentiation of a few cell types and bone regeneration. The aim of the current study was to investigate whether NF-PLLA scaffolds are advantageous for the odontogenic differentiation and mineralization of human dental pulp stem cells (DPSCs) over solid-walled (SW) PLLA scaffolds. The vitro studies demonstrated that, compared with SW scaffolds, NF scaffolds enhanced attachment and proliferation as well as odontogenic differentiation of human DPSCs. The alkaline phosphatase (ALP) activity and the expression of odontogenic genes of human DPSCs was increased on NF scaffolds compared with that on SW scaffolds. In addition, more mineral deposition was observed on the NF scaffolds as demonstrated by von Kossa staining, calcium content measurement and scanning electron microscopy. Consistent with the in vitro studies, NF scaffolds promoted odontogenic differentiation and hard tissue formation compared with SW scaffolds after 8 weeks of ectopic transplantation in nude mice as confirmed by von Kossa staining, Masson’s trichrome staining and immunohistochemical staining for dentin sialoprotein. In conclusion, NF-PLLA scaffolds enhanced the odontogenic differentiation of human DPSCs and mineralization both in vitro and in vivo, and are promising scaffolds for dentin regeneration. PMID:21663962

Wang, Jing; Ma, Haiyun; Jin, Xiaobing; Hu, Jiang; Liu, Xiaohua; Ni, Longxing; Ma, Peter X.

2011-01-01

142

Surgical management of dentigerous cyst and keratocystic odontogenic tumor in children: a conservative approach and 7-year follow-up  

PubMed Central

Dentigerous cyst (DC) is one of the most common odontogenic cysts of the jaws and rarely recurs. On the other hand, keratocystic odontogenic tumor (KCOT), formerly known as odontogenic keratocyst (OKC), is considered a benign unicystic or multicystic intraosseous neoplasm and one of the most aggressive odontogenic lesions presenting relatively high recurrence rate and a tendency to invade adjacent tissue. Two cases of these odontogenic lesions occurring in children are presented. They were very similar in clinical and radiographic characteristics, and both were treated by marsupialization. The treatment was chosen in order to preserve the associated permanent teeth with complementary orthodontic treatment to direct eruption of the associated permanent teeth. At 7-years of follow-up, none of the cases showed recurrence. PMID:22666848

DEBONI, Maria Cristina Zindel; BROZOSKI, Mariana Aparecida; TRAINA, Andreia Aparecida; ACAY, Renata Rodrigues; NACLERIO-HOMEM, Maria da Graca

2012-01-01

143

Ameloblastomatous calcifying ghost cell odontogenic cyst - a rare variant of a rare entity  

PubMed Central

Summary Calcifying odontogenic cyst (COC) is an uncommon benign cystic neoplasm of odontogenic origin, which shows extensive diversity in its clinico-pathological appearances and biological behavior. It most commonly occurs in broader age group of 1–82 years in anterior part of jaws which is classically described by presence of ghost cells. There are variants of COC according to clinical, histopathological, and radiological characteristics. Therefore a proper categorization of the cases is needed for better understanding of the pathogenesis of each variant. Here we report a rare case of ameloblastomatous calcifying ghost cell odontogenic cyst in 24 year old female with brief review of literature. Presence of ameloblastomatous proliferation and impacted canine presented a diagnostic dilemma and was diagnosed by careful radiographic and histopathogical interpretation. Long follow up and more case report are required to shed light on its behaviour as there scarcity of data of this lesion in literature. PMID:23741537

Singh, Harkanwal Preet; Yadav, Madhulika; Nayar, Amit; Verma, Chanchal; Aggarwal, Palak; Bains, Sandeep Kumar

2013-01-01

144

Central granular cell odontogenic tumor: the first reported case in Oriental people and literature review.  

PubMed

The central granular cell odontogenic tumor (CGCOT) is a rare odontogenic neoplasm, usually occurring in the mandible of middle-aged women. Previous studies have reported only 34 cases, all of whom were white or black individuals. The present study reports an additional case of CGCOT, occurring in the posterior mandible of a 69-year-old Taiwanese man. To the authors' knowledge, this is the first reported case in Oriental people. The odontogenic epithelium exhibited strong positive immunoreactivity for pan-cytokeratin, and focal weak staining for bcl-2. The granular cells showed strong positivity for vimentin and ?1-antichymotrypsin, and focal weak staining for carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), and CD68. These features indicated a mesenchymal origin and possible histiocytic lineage for the granular cells. This study also presents a literature review and describes immunohistochemical features of the tumor. PMID:24428977

Chiang, Chien-Ta; Hu, Kwang-Yu; Tsai, Chien-Chen

2014-05-01

145

Mural Adenomatoid Odontogenic Tumour as Anterior Mandibular Swelling: A Diagnostic Challenge  

PubMed Central

Adenomatoid odontogenic tumour is an uncommon, benign, hamartomatous lesion that commonly affects the anterior maxilla and has two radiographic variants, follicular and extrafollicular where the former is more common than the latter. Here, we report a case of 15-year-old female with midline swelling of the mandible. Radiographically, impacted right permanent mandibular canine was associated with the radiolucent lesion. Dentigerous cyst was given as provisional diagnosis. However, histologically the lesion represented the features of cystic variant of Adenomatoid odontogenic tumour. PMID:25121073

Sarkar, Reena Bhola; Grewal, Jessica; Grewal, Ripin; Bansal, Arun

2014-01-01

146

Predictive Factors of Potential Malignant Transformation in Recurrent Calcifying Cystic Odontogenic Tumor: Review of the Literature  

PubMed Central

Calcifying cystic odontogenic tumor (CCOT) demonstrates considerable diversity in histopathology and clinical behavior. Ghost cell odontogenic carcinoma (GCOC) is the rare malignant counterpart of CCOT and it frequently arises from malignant transformation of a recurrent CCOT. In this paper, we present a case of CCOT and discuss its distinct histopathologic features in recurrence. Then, we will have a review on clinical, histopathological, and immunohistochemical aspects of GCOC in the literature. Predictive factors of malignant transformation in a benign CCOT will also be discussed. PMID:23956907

Mokhtari, Sepideh; Mohsenifar, Zhaleh; Ghorbanpour, Maedeh

2013-01-01

147

Adenomatoid odontogenic tumor in the maxillary antrum: A rare case entity.  

PubMed

Adenomatoid odontogenic tumor (AOT) is an uncommon benign tumor of odontogenic origin. It occurs in the second decade of life. Females are more commonly affected than males. AOT has a striking tendency to occur in the anterior maxilla; however, very few cases have been reported to occur in the maxillary antrum. This is a case report of a 17-year-old male presented with a large radiolucent lesion associated with the crown of an unerupted canine located in the right maxillary antrum, which was clinically diagnosed as dentigerous cyst. The histopathological examination revealed the presence of AOT. PMID:25210372

Krishnamurthy, Kavitha; Balaji, Ranjith Singh; Devadiga, Sumana; Prasad, Rame Gowda Rajendra

2014-07-01

148

Infection!  

NSDL National Science Digital Library

This activity from the American Museum of Natural History's family magazine series is a board game in which kids learn how germs spread and infections take hold. The online activity begins with an overview of the many ways germs can enter your body and the body's first and second lines of defense. Kids then go to a page of directions for playing the online game, where they are also asked to select a microbe playing piece. As they move through the playing board, kids gain insight into how the body fights infection.

149

Conservative Management of Keratocystic Odontogenic Tumors of Jaws  

PubMed Central

Purpose. The aim of this study was to evaluate different surgical treatment methods for keratocystic odontogenic tumors (KCOTs) and the outcome of those treatments over a 9-year period. Patients and Methods. A retrospective review was performed on 43 KCOTs in 39 patients. In radiographic evaluations for diagnosis, follow ups and before and after treatment, panoramic, 3D CT and MR images were used. The three groups of different surgical treatment were (1) enucleation for small unilocular lesions without certainty of histology; (2) enucleation with Carnoy's solution, for small unilocular lesions after previous histological confirmation of KOCT; (3) marsupialization followed by enucleation with Carnoy's solution implemented for large often multilocular KCOTs with intact or destruction of cortical bone without infiltration of neighbouring tissue. Results. 43 KCOT cases were mostly localized in mandible (76.7%), radiologically unilocular (72%), and parakeratocysts (88.4%). Inflammation and satellite cysts (daughter cysts) were detected histopathologically in 14 (32.5%) and 7 (16.3%), respectively. Among the 43 cysts, 20 (46.5%) were associated with the impacted third molar and of 21 (48.8%) was in tooth bearing area, and 5 (11, 6%) located on edentulous areas. It was located mostly in the anterior region of maxilla (90%) and in mandibular molar and ramus (62.8%). The treatments of KCOTs were 18 (41.9%) for group 1, and 10 (23.3%) group 2, and 15 (34.8%) group 3. A statistically significant relationship was found between the radiographic appearance and treatment methods (P = 0.00). No recurrence was found on 40.54 ± 23.02 months follow up. Conclusion. We concluded that successful treatment methods were enucleation and Carnoy's solution in small lesions and marsupialization in lesions that have reached a very large size, but because KCOT was observed in second decade mostly, long-term follows up are suggested. PMID:22454609

Guler, Nurhan; Sencift, Kemal; Demirkol, Ozge

2012-01-01

150

Nuclear Factor I-C Is Essential for Odontogenic Cell Proliferation and Odontoblast Differentiation during Tooth  

E-print Network

Nuclear Factor I-C Is Essential for Odontogenic Cell Proliferation and Odontoblast Differentiation York 14214-3092 Our previous studies have demonstrated that nuclear factor I-C (NFI-C) null mice and primary pulp cells from Nfic-deficient mice in vitro. Cell proliferation analysis of both cervical loop

Gronostajski, Richard M.

151

The orosomucoid 1 protein (?1 acid glycoprotein) is overexpressed in odontogenic myxoma  

PubMed Central

Background Odontogenic myxoma (OM) is a benign, but locally invasive, neoplasm occurring in the jaws. However, the molecules implicated in its development are unknown. OM as well as Dental Follicle (DF), an odontogenic tissue surrounding the enamel organ, is derived from ectomesenchymal/mesencyhmal elements. To identify some protein that could participate in the development of this neoplasm, total proteins from OM were separated by two-dimensional electrophoresis and the profiles were compared with those obtained from DF, used as a control. Results We identified eight proteins with differential expression; two of them were downregulated and six upregulated in OM. A spot consistently overexpressed in odontogenic myxoma, with a molecular weight of 44-kDa and a pI of 3.5 was identified as the orosomucoid 1 protein. Western blot experiments confirmed the overexpression of this protein in odontogenic myxoma and immunohistochemical assays showed that this protein was mainly located in the cytoplasm of stellate and spindle-shaped cells of this neoplasm. Conclusion Orosomucoid 1, which belongs to a group of acute-phase proteins, may play a role in the modulation of the immune system and possibly it influences the development of OM. PMID:22888844

2012-01-01

152

Clinical, radiological and therapeutic features of keratocystic odontogenic tumours: a study over a decade  

PubMed Central

Factors associated with the potential for recurrence of keratocystic odontogenic tumours (KCOT) still remain to be clearly determined and no consensus exists concerning the management of KCOT. The purpose of this study was to evaluate different clinical factors associated with KCOT and its treatment methods. A retrospective review was performed of 55 cases treated from 2001 to 2010. Of the 55 cases, 27% were associated with an impacted or semi-impacted tooth. The majority of the lesions (82%) were located in tooth-bearing areas, and the overall mandibular to maxilla ratio of tumour occurrence was 5:1. The treatment options included enucleation, marsupialisation, or peripheral ostectomy, with or without the use of Carnoy´s solution. Recurrence was found in 14 cases (25%). No significant association was seen between recurrence and age, symptomatic cases, location of the lesion, or unilocular or multilocular appearance. The recurrence rate was higher in the group with tooth involvement, more marked in cases with third molar involvement. Statistical analysis showed a significant relation between recurrence and the type of treatment, with higher rates in cases treated with enucleation associated with tooth extraction. In our series, those cases with a closer relation with dental tissues showed a higher risk of recurrence, suggesting the need for a distinct classification for peripheral variants of KCOT. Key words:Keratocystic odontogenic tumour, Odontogenic keratocyst, Odontogenic cysts, Keratocyst, Carnoy’s solution. PMID:25136427

Gonzalez-Martin-Moro, Javier; Perez-Fernandez, Elia; Burgueno-Garcia, Miguel

2014-01-01

153

c-Myc oncogene expression in selected odontogenic cysts and tumors: An immunohistochemical study  

PubMed Central

Aim: To investigate the role of c-Myc oncogene in selected odontogenic cysts and tumors. Materials and Methods: Ten cases each of ameloblastoma, adenomatoid odontogenic tumor (AOT), odontogenic keratocyst (OKC), dentigerous cyst, and radicular cyst were selected and primary monoclonal mouse anti-human c-Myc antibody was used in a dilution of 1: 50. Statistical Analysis was performed using Mann Whitney U test. Results: 80% positivity was observed in ameloblastoma, AOT and OKC; 50% positivity in radicular cyst and 20% positivity in dentigerous cyst. Comparison of c-Myc expression between ameloblastoma and AOT did not reveal significant results. Similarly, no statistical significance was observed when results of OKC were compared with ameloblastoma and AOT. In contrast, significant differences were seen on comparison of dentigerous cyst with ameloblastoma and AOT and radicular cyst with AOT. Conclusion: From the above data we conclude that (1) Ameloblastoma and AOT have similar proliferative potential and their biologic behavior cannot possibly be attributed to it. (2) OKC has an intrinsic growth potential which is absent in other cysts and reinforces its classification as keratocystic odontogenic tumor. PMID:23798830

Moosvi, Zama; Rekha, K

2013-01-01

154

Intramuscular keratocyst as a soft tissue counterpart of keratocystic odontogenic tumor: differential diagnosis by immunohistochemistry.  

PubMed

Keratocystic odontogenic tumor (KCOT), a developmental jaw cyst previously referred to as odontogenic keratocyst (OKC), typically arises in the jawbone. In this article, however, we report a case of KCOT located within the temporalis muscle. We compared its immunohistochemical profiles with those of authentic jaw KCOT, orthokeratinized odontogenic cyst, and epidermoid cyst in order to consider whether a soft tissue counterpart of KCOT could be a separate disease entity. The patient was a 46-year-old man with a well-defined cystic lesion within the left temporalis muscle. On computed tomographic images, the lesion was recognized as a cystic lesion, although KCOT was not included in the clinical differential diagnoses. The location of the lesion was not within bone but, rather, within the temporalis muscle that was attached to the jawbones. Our review of the literature has disclosed more than 20 peripheral KCOT cases of the oral mucosa and more than 10 cases of the skin, but only 1 case arising in muscle. Immunohistochemical investigation of the present intramuscular case reveals KCOT-characteristic profiles distinct from the other 3 types of cysts investigated. The results indicate that KCOT-like lesions can arise within soft tissues, although use of the term odontogenic might seem inappropriate in those cases. PMID:24182558

Abé, Tatsuya; Maruyama, Satoshi; Yamazaki, Manabu; Essa, Ahmed; Babkair, Hamzah; Mikami, Toshihiko; Shingaki, Susumu; Kobayashi, Tadaharu; Hayashi, Takafumi; Cheng, Jun; Saku, Takashi

2014-01-01

155

Collagen and Elastic Fibers in Odontogenic Entities: Analysis Using Light and Confocal Laser Microscopic Methods  

PubMed Central

Dentigerous cyst (DC) and keratocystic odontogenic tumor (KOT) are odontogenic lesions arising from epithelial elements, such as those observed in dental follicles (DF), that have been part of the tooth forming apparatus. These lesions show different clinical and histological characteristics, as well as distinct biological behavior. This study aimed to qualify and quantify collagen and elastic fibers by means of histochemical techniques with light and confocal laser microscopic methods in three odontogenic entities. Eleven DF, 13 DC (n=10 with inflammation, n=3 without inflammation) and 13 KOT were processed to the following techniques: Hematoxylin and Eosin, Masson’s Trichrome, Picrosirius, Direct Blue, and Orcein. DF and DC without inflammation exhibited collagen with similar characteristics: no parallel pattern of fiber orientation, thick fibers with dense arrangement, and absence of distinct layers. A comparison between DC with inflammation and KOT revealed similar collagen organization, showing distinct layers: thin collagen fibers with loose arrangement near the epithelium and thick fibers with dense arrangement in distant areas. The only difference found was that KOT exhibited a parallel collagen orientation in relation to the odontogenic epithelia. It may be suggested that the connective tissue of DC is a reactive tissue, inducing an expansive growth associated with fluid accumulation and inflammatory process, which in turn may be present as part of the lesion itself. In KOT, loosely arranged collagen may be associated with the behavior of the neoplastic epithelium. PMID:21760864

Moure, Sabrina P; Carrard, Vinicius C; Lauxen, Isabel S; Manso, Pedro Paulo A; Oliveira, Marcia G; Martins, Manoela D; Sant?Ana Filho, Manoel

2011-01-01

156

Immunohistochemical detection of laminin-1 and Ki-67 in radicular cysts and keratocystic odontogenic tumors  

PubMed Central

Background Odontogenic cysts are those which arise from the epithelium associated with the development of teeth. Some odontogenic cysts were found to have special biological features that make them distinct from other lesions. This study was conducted to detect the immunoepxression of laminin-1 and Ki-67 in both radicular cysts (RCs) and keratocystic odontogenic tumors (KCOTs) and to examine the possible predictive value of these markers. Methods Thirteen cases of RCs and twelve cases of KCOTs were included in this study. Antibodies against laminin-1 and Ki-67 were used as primary antibodies. Results ten cases out of thirteen cases of RCs were immunopositive to laminin-1. The immunonegative cases of RCs showed high degree of inflammation inside the connective tissue wall. One case out of twelve cases of KCOTs was immunopositive to laminin-1 and the rest were immunonegative. Seven cases out of thirteen cases of RCs showed immunopositivity for Ki-67 with increased numbers of immunopositive cells when the inflammation was severe in the connective tissue wall. All KCOTS were immunopositive to Ki-67. Conclusions The benign nature of radicular cysts and the aggressive behavior of keratocystic odontogenic tumors could be explained by the expression of laminin and Ki-67. Laminin-1 and Ki-67 could be valuable markers for the prediction of the biologic behavior of cystic lesions. PMID:21366912

2011-01-01

157

THERMOPHILIC ANAEROBIC BIODEGRADATION OF PHENOLICS  

EPA Science Inventory

The report gives results of a series of anaerobic microbial acclimation and treatment performance tests with synthetic phenolic substrates. The research is a feasibility level assessment of substituting anaerobic biodegradation of phenolics for solvent extraction. The tests showe...

158

Comparative In Vitro Susceptibilities of 396 Unusual Anaerobic Strains to Tigecycline and Eight Other Antimicrobial Agents?  

PubMed Central

Tigecycline was tested against 396 strains of lesser-known anaerobic species encountered in human infections. It was active against all gram-positive strains and 228 of 232 gram-negative anaerobes at ?1 ?g/ml. One strain of Prevotella oralis was nonsusceptible at 8 ?g/ml. PMID:16940056

Goldstein, Ellie J. C.; Citron, Diane M.; Merriam, C. Vreni; Warren, Yumi A.; Tyrrell, Kerin L.; Fernandez, Helen T.

2006-01-01

159

Deep sequencing-based analysis of the anaerobic stimulon in Neisseria gonorrhoeae  

Microsoft Academic Search

BACKGROUND: Maintenance of an anaerobic denitrification system in the obligate human pathogen, Neisseria gonorrhoeae, suggests that an anaerobic lifestyle may be important during the course of infection. Furthermore, mounting evidence suggests that reduction of host-produced nitric oxide has several immunomodulary effects on the host. However, at this point there have been no studies analyzing the complete gonococcal transcriptome response to

Vincent M Isabella; Virginia L Clark

2011-01-01

160

In vitro activity of Bay 12-8039, a new 8-methoxyquinolone, compared to the activities of 11 other oral antimicrobial agents against 390 aerobic and anaerobic bacteria isolated from human and animal bite wound skin and soft tissue infections in humans.  

PubMed Central

The in vitro activity of Bay 12-8039, a new oral 8-methoxyquinolone, was compared to the activities of 11 other oral antimicrobial agents (ciprofloxacin, levofloxacin, ofloxacin, sparfloxacin, azithromycin, clarithromycin, amoxicillin clavulanate, penicillin, cefuroxime, cefpodoxime, and doxycycline) against 250 aerobic and 140 anaerobic bacteria recently isolated from animal and human bite wound infections. Bay 12-8039 was active against all aerobic isolates, both gram-positive and gram-negative isolates, at < or = 1.0 microg/ml (MICs at which 90% of isolates are inhibited [MIC90s < or = 0.25 microg/ml) and was active against most anaerobes at < or = 0.5 microg/ml; the exceptions were Fusobacterium nucleatum and other Fusobacterium species (MIC90s, > or = 4.0 microg/ml) and one strain of Prevotella loeschii (MICs, 2.0 microg/ml). In comparison, the other quinolones tested had similar in vitro activities against the aerobic strains but were less active against the anaerobes, including peptostreptococci, Porphyromonas species, and Prevotella species. The fusobacteria were relatively resistant to all the antimicrobial agents tested except penicillin G (one penicillinase-producing strain of F. nucleatum was found) and amoxicillin clavulanate. PMID:9210683

Goldstein, E J; Citron, D M; Hudspeth, M; Hunt Gerardo, S; Merriam, C V

1997-01-01

161

Anaerobic thermophilic culture system  

DOEpatents

A mixed culture system of the newly discovered microorganism Thermoanaerobacter ethanolicus ATCC31550 and the microorganism Clostridium thermocellum ATCC31549 is described. In a mixed nutrient culture medium that contains cellulose, these microorganisms have been coupled and cultivated to efficiently ferment cellulose to produce recoverable quantities of ethanol under anaerobic, thermophilic conditions.

Ljungdahl, Lars G. (Athens, GA); Wiegel, Jurgen K. W. (Gottingen, DE)

1981-01-01

162

Malignant Transformation of an Odontogenic Cyst in a Period of 10 Years  

PubMed Central

Primary intraosseous carcinoma of the jaws (PIOSCC) might arise from odontogenic epithelium, more commonly from a previous odontogenic cyst. The aim of this case is to illustrate that the clinician should consider that an apparent benign dentigerous cyst can suffer malignant transformation and that all material removed from a patient must be evaluated histologically. A 44-year-old man presented in a routine periapical X-ray an impacted lower left third molar with radiolucency over its crown. Ten years later, the patient complained of pain in the same region and the tooth was extracted. After one month, the patient still complained of pain and suffered a fracture of the mandible. A biopsy was performed and carcinoma was diagnosed. The patient was treated surgically with adjuvant radio- and chemotherapy and after 8 years, he is well without signs of recurrences. This report describes a central mandibular carcinoma probably developed from a previous dentigerous cyst. PMID:24804126

Araujo, Juliane Piragine; Kowalski, Luiz Paulo; Rodrigues, Monica Lucia; de Almeida, Oslei Paes; Lopes Pinto, Clovis Antonio; Alves, Fabio Abreu

2014-01-01

163

A large odontogenic myxoma of the bilateral maxillae: A case report  

PubMed Central

Odontogenic myxomas (OMs) are benign mesenchymal locally aggressive neoplasms of the jaw bone. Although OMs predominantly involve the mandible, maxillary tumors are usually more aggressive than mandibular tumors. The present study describes the case of a 37-year-old male with a large odontogenic myxoma of the bilateral maxillae, which caused a defect in the right skull base bone. The tumor was successfully removed through radical resection of the hard tissue and local resection around the envelope of the soft tissue. The tumor exhibited no recurrence. However, the current methods for bilateral maxillary reconstruction to restore the maxillary buttress and achieve an optimal aesthetic appearance are complicated due to the lack of suitable conditions for oral rehabilitation with good dentition. PMID:25120718

LIU, YING; HAN, BO; YU, TAO; LI, LONGJIANG

2014-01-01

164

Clear cell odontogenic carcinoma of maxilla: A case report and mini review  

PubMed Central

Clear cell odontogenic carcinoma is a rare odontogenic tumor occurring predominantly in posterior mandible during 5th-7th decades with a female predilection. It is a potentially aggressive tumor, capable of frequent recurrences and loco-regional and distant metastases. Till date, only 73 cases have been reported in the literature. Current case is of a 55-year-old woman with tumor mass extending from canine to molar region on the left maxillary arch. Being locally aggressive tumor with the capacity to metastasize, it demands to be distinguished from other primary and metastatic clear cell tumors of the oral and maxillofacial region. A brief compilation of the reported cases is being attempted in the current article to better understand the behavior of the tumor. PMID:23798837

Swain, Niharika; Dhariwal, Richa; Ray, Jay Gopal

2013-01-01

165

A case of orthokeratinized odontogenic cyst suspected to be a radicular cyst.  

PubMed

This report describes a case of orthokeratinized odontogenic cyst arising in the mandibular molar region of a 39-year-old man. Under the initial clinical diagnosis of radicular cyst, root canal treatment was performed on the mandibular right second molar. The treatment that continued for six months did not achieve healing. Subsequently surgical intervention was selected since the tooth fracture was found, and the prognosis was judged to be poor. After atraumatic tooth extraction, the apical cystic lesion was enucleated, and the tooth was replanted. A definite diagnosis of orthokeratinized odontogenic cyst was made by histopathological examination of the biopsy specimen. The radiograph taken seven months after the operation showed an improvement in the radiolucent lesion. No clinical signs of tooth mobility, pain, and swelling were present. The tooth was then successfully retained with the final restoration. Careful follow-up is needed in order to detect any signs of recurrence. PMID:19622877

Onuki, Mizuho; Saito, Atsushi; Hosokawa, Sohei; Ohnuki, Tomohiro; Hayakawa, Hiroki; Seta, Shuichi; Muramatsu, Takashi; Furusawa, Masahiro

2009-02-01

166

Infiltrative odontogenic myxoma of the posterior maxilla: Report of a case  

PubMed Central

Myxomas of the head and neck are rare tumors of uncertain histogenesis. Odontogenic myxomas in maxilla are less common but behave more aggressively, as it spreads through maxillary antrum. It therefore reaches considerable size before being detected. The current case arouses particular interest due to the rapid growth and infiltrating nature of the lesion in a 25-year-old female patient, who denied any leading symptoms, even with the lesion involving extensively. Radiographic and microscopic similarities to a number of entities make diagnostic interpretation of odontogenic myxoma challenging. Therefore sound knowledge of clinical, radiographic and histopathologic features is important to establish an appropriate treatment aimed at a good clinical course and patient cure. PMID:24082760

Arul, A. Sri Kennath J.; Verma, Sonika; Arul, A. Sri Sennath J.; Verma, Rashmika

2013-01-01

167

Clear cell odontogenic carcinoma mimicking a cystic lesion: a case of misdiagnosis  

PubMed Central

Clear cell odontogenic carcinoma (CCOC) is a rare jaw tumor that was classified as a malignant tumor of odontogenic origin in 2005 by the World Health Organization because of its aggressive and destructive growth capacity and metastasis to the lungs and lymph nodes. We report a case of a 66-year-old female who had swelling, incision and drainage history and a well-defined unicystic radiolucent lesion that was comparable to a cystic lesion. At first, the patient received decompression, and the lesion size decreased. Three months after decompression, cyst enucleation was performed. The pathologic result indicated that the lesion was CCOC. In this report we emphasize that patients with painful cystic lesions in addition to jaw enlargement and loosening teeth should be considered for the possibility of malignancy.

Kim, Minkyu; Cho, Eunae; Kim, Jae-Young; Kim, Hyun Sil

2014-01-01

168

Perspectives for anaerobic digestion.  

PubMed

The modern society generates large amounts of waste that represent a tremendous threat to the environment and human and animal health. To prevent and control this, a range of different waste treatment and disposal methods are used. The choice of method must always be based on maximum safety, minimum environmental impact and, as far as possible, on valorization of the waste and final recycling of the end products. One of the main trends of today's waste management policies is to reduce the stream of waste going to landfills and to recycle the organic material and the plant nutrients back to the soil. Anaerobic digestion (AD) is one way of achieving this goal and it will furthermore, reduce energy consumption or may even be net energy producing. This chapter aims at provide a basic understanding of the world in which anaerobic digestion is operating today. The newest process developments as well as future perspectives will be discussed. PMID:12747559

Ahring, Birgitte K

2003-01-01

169

The Prevalence of Inflammatory and Developmental Odontogenic Cysts in a Libyan Population  

PubMed Central

Objective The aim of this study was to determine the prevalence of odontogenic jaw cysts in a Libyan population and to compare the data with previously published reports from other countries. Materials and methods We retrieved and analyzed 2190 case notes and biopsy records of the Department of Oral and Maxillofacial Surgery and the Department of Oral Pathology and Microbiology, Al Arab Medical Sciences University, Benghazi, Libya, dating from January 1990 to December 2005. There were 326 cases (14.8%) of diagnosed odontogenic cysts among the 2190 biopsies performed during this period. The cases were analyzed for age and sex distribution, site of presentation, association with impacted teeth, and the method of treatment. Results The male to female ratio of patients was 1.3:1 Radicular cysts accounted for 222 cases (68.1%), followed by dentigerous cysts (n=49, 15%) and odontogenic keratocysts (n=43, 14.1%). Mean ages of the patients were, respectively, 31.7, 22.7 and 36.1 years. The maxilla was more commonly involved than the mandible (1.3:1). The anterior maxilla was the commonest site (n=132, 37.4%) followed by the posterior mandible (n=96, 29.4%). Fifty three cases were associated with impacted teeth, and the highest frequency was for dentigerous cysts (n=37). Enucleation and curettage was performed on 300 patients, marsupialization on 14, and marginal/segmental resection on 12. Conclusion To our knowledge, this is the first such study on a Libyan population. Our results are comparable to studies from other countries. Knowledge of the relative frequencies and sites of presentation of odontogenic cysts in different ethno-geographic backgrounds is essential for the early diagnosis and management of these benign yet potentially destructive lesions. PMID:21499462

El Gehani, R; Krishnan, B; Orafi, H

2008-01-01

170

Comparison of Odontogenic Differentiation of Human Dental Follicle Cells and Human Dental Papilla Cells  

PubMed Central

Classical tooth development theory suggests that dental papilla cells (DPCs) are the precursor cells of odontoblasts, which are responsible for dentin development. However, our previous studies have indicated that dental follicle cells (DFCs) can differentiate into odontoblasts. To further our understanding of tooth development, and the differences in dentinogenesis between DFCs and DPCs, the odontogenic differentiation of DFCs and DPCs was characterized in vitro and in vivo. DFCs and DPCs were individually combined with treated dentin matrix (TDM) before they were subcutaneously implanted into the dorsum of mice for 8 weeks. Results showed that 12 proteins were significantly differential, and phosphoserine aminotransferase 1 (PSAT1), Isoform 2 of hypoxia-inducible factor 1-alpha (HIF1A) and Isoform 1 of annexin A2 (ANXA2), were the most significantly differential proteins. These proteins are related to regulation of bone balance, angiogenesis and cell survival in an anoxic environment. Both DFCs and DPCs express odontogenic, neurogenic and peridontogenic markers. Histological examination of the harvested grafts showed that both DFCs and DPCs form pulp-dentin/cementum-periodentium-like tissues in vivo. Hence, DFCs and DPCs have similar odontogenic differentiation potential in the presence of TDM. However, differences in glucose and amino acid metabolism signal transduction and protein synthesis were observed for the two cell types. This study expands our understanding on tooth development, and provides direct evidence for the use of alternative cell sources in tooth regeneration. PMID:23620822

Qiao, Xiangchen; Yu, Mei; Tang, Wei; Wang, Hang; Guo, Weihua; Tian, Weidong

2013-01-01

171

Evaluation and comparison of expression of p63 in odontogenic keratocyst, solid ameloblastoma and unicystic ameloblastoma  

PubMed Central

Background and Objectives: The behavior of odontogenic lesions varies with some tumors behaving like a cyst and some cysts behaving like tumors. p63, a member of the p53 family of tumor suppressor genes has recently come into light in view of its role as an oncogene. The aim of the present study was to investigate the expression of p63 protein in OKC, Solid ameloblastoma, Unicystic Ameloblastoma and Follicular tissue. Materials and Methods: p63 expression was compared in 12 cases of OKC, 12 Solid Ameloblastoma, 14 cases of Unicystic ameloblastoma and 10 cases of Follicular tissue using immunohistochemical technique. All 48 cases were subjected to heat-induced antigen retrieval method using citrate buffer in a pressure cooker. Then the sections were stained with anti-p63 polyclonal antibody and visualized using super sensitive polymer HRP detection system. In each case, number of cells showing p63 positivity were assessed in two compartments - basal and suprabasal and compared. Results: Statistical analysis showed that p63 expression in the suprabasal compartment in Odontogenic keratocysts was equivalent to that of central neoplastic cells of Solid Ameloblastoma and Unicystic Ameloblastoma type 3. Statistically significant difference in the expression of p63 was observed between OKC and Unicystic Ameloblastoma Type 1 and Solid Ameloblastoma and Unicystic Ameloblastoma Type 1. Conclusion: We conclude that the higher expression of p63 in these odontogenic lesions correlates well with their aggressive behavior and thereby suggesting alterations in treatment modalities. PMID:25328303

Varsha, BK; Gharat, A Leena; Nagamalini, BR; Jyothsna, M; Mothkur, Sahana T; Swaminathan, Uma

2014-01-01

172

Differences in collagen fibres in the capsule walls of parakeratinized and orthokeratinized odontogenic cysts.  

PubMed

Epithelial-mesenchymal interactions are thought to play an important role in the pathogenesis of odontogenic lesions. Keratocystic odontogenic tumour (KCOT) is a benign cystic neoplasm with a characteristic parakeratinized epithelial lining, which differs histologically and behaviourally from the so-called orthokeratinized odontogenic cyst (OOC). The purpose of this study was to investigate the differences in collagen fibres within the fibrous tissue walls of KCOT and OOC. Formalin-fixed paraffin-embedded tissue samples from 15 cases of KCOT and 15 cases of OOC were collected. Paraffin sections were stained with picrosirius red and observed under a standard light microscope using optical polarization. Unicystic ameloblastoma (UA, 15 cases) and subcutaneous epidermoid cysts (EC, 15 cases) were included in the study for comparative purposes. Significant difference was detected between the polarization colours in the fibrous tissue walls of KCOT and OOC (P<0.05), whilst no significant differences were found between KCOT and UA and between OOC and EC (P>0.05). The stromal collagen fibres of KCOT were different from those of OOC, but similar to those of UA, which suggests that the stroma of KOCT may play an important role in determining the neoplastic behaviour of the lesion through epithelial-mesenchymal interaction. PMID:21741212

Zhang, J-Y; Dong, Q; Li, T-J

2011-11-01

173

Evidence of loss of heterozygosity of the PTCH gene in orthokeratinized odontogenic cyst.  

PubMed

The orthokeratinized odontogenic cyst (OOC) is an odontogenic cyst of unknown etiology. Clinical, histological, and biological differences are reported between keratocystic odontogenic tumor (KOT) and OOC. PTCH is a tumor suppressor gene related to sonic hedgehog (SHH) pathway important in embryological development. Considering that alterations in this pathway have been described in sporadic and nevoid basal cell syndrome-associated KOT, we tested the hypothesis that OOC is also associated with loss of heterozygosity (LOH) of the PTCH gene. Seven samples of OOC and seven of KOT were included in the study. D9S287, D9S196, and D9S127 microsatellite markers located in the region of PTCH gene, at chromosome 9q, were investigated for LOH. There was loss in at least one locus in 5/7 KOT and in 4/7 OOC samples. The present finding demonstrates that, despite the existence of clinical, morphological, immunohistochemical, and biological behavior differences between OOC and KOT, both harbor similar genetic alterations at 9q. PMID:21138481

Diniz, Marina Gonçalves; Galvão, Clarice Ferreira; Macedo, Paula Serelle; Gomes, Carolina Cavaliéri; Gomez, Ricardo Santiago

2011-03-01

174

Involvement of periodontopathic anaerobes in aspiration pneumonia.  

PubMed

Increasing evidence has linked the anaerobic bacteria forming periodontopathic biofilms with aspiration pneumonia in elderly persons. In experiments designed to eliminate the potent respiratory pathogens forming biofilms in the oral cavity, we have shown that the mechanical and chemical oral cleansing using povidone-iodine effectively reduced the detection rates and numbers of methicillin-sensitive Staphylococcus species, Streptococcus pneumoniae, and Haemophilus influenzae in patients scheduled to undergo oral surgery requiring endotracheal intubation. We confirmed the pathogenicity of periodontopathic anaerobic bacteria for aspiration pneumonia in an experimental mouse model. Based upon the finding of the coexistence of Porphyromonas gingivalis with Treponema denticola in chronic periodontitis lesions, we innoculated a mixed culture of P. gingivalis and T. denticola into the mouse trachea; the resulting infection induced inflammatory cytokine production and caused pneumonia. In another series of investigations, professional oral health care (POHC), mainly cleansing administered by dental hygienists once a week for 24 months to elderly persons requiring daily care, resulted in the reduction of the number of total anaerobes, Candida albicans, and Staphylococcus species and in the number of cases of fatal aspiration pneumonia. We also found that the POHC treatment of elderly persons for 6 months in the winter season reduced the salivary levels of protease, trypsin-like activity, and neuraminidase and also decreased the frequency of influenza cases. PMID:16277588

Okuda, Katsuji; Kimizuka, Ryuta; Abe, Shu; Kato, Tetsuo; Ishihara, Kazuyuki

2005-11-01

175

Effect of lactoferrin on odontogenic differentiation of stem cells derived from human 3rd molar tooth germ.  

PubMed

Stem cell technology has been a great hope for the treatment of many common tissue regeneration-related diseases. Therefore, the main challenge in hard tissue engineering is to make a successful combination of stem cells and efficient inductors such as biomaterials or growth factors, in the concept of stem cell conversion into odontogenic cell. Even though lactoferrin has been reported to promote bone growth in vivo, the molecular mechanism of teeth formation has not been elucidated yet. Different concentrations of lactoferrin were prepared for the analysis of cell toxicity and differentiation evaluations. The odontogenic differentiation of human tooth germ stem cells (hTGSCs) was assessed by gene expression analysis, determination of protein levels in odontogenic differentiation-related protein, measuring alkaline phosphatase (ALP) activity, mineralization, and calcium deposit levels. Lactoferrin-treated group showed the highest ALP activity as opposed to the other groups which were untreated. In addition, the gene expression levels as well as the protein levels of odontogenic factors were found to be high in compared to the control groups. In the current study, it is shown for the first time that there is a significant increase in odontogenic differentiation capacity in hTGSCs when lactoferrin is applied in vitro. The study offers a considerable promise for the development of pulp regeneration by using stem cell technology combined with lactoferrin in functional tooth tissue engineering. PMID:25173676

Ta?l?, Pakize Neslihan; Sahin, Fikrettin

2014-11-01

176

Anaerobic wastewater treatment using anaerobic baffled bioreactor: a review  

NASA Astrophysics Data System (ADS)

Anaerobic wastewater treatment is receiving renewed interest because it offers a means to treat wastewater with lower energy investment. Because the microorganisms involved grow more slowly, such systems require clever design so that the microbes have sufficient time with the substrate to complete treatment without requiring enormous reactor volumes. The anaerobic baffled reactor has inherent advantages over single compartment reactors due to its circulation pattern that approaches a plug flow reactor. The physical configuration of the anaerobic baffled reactor enables significant modifications to be made; resulting in a reactor which is proficient of treating complex wastewaters which presently require only one unit, ultimately significant reducing capital costs. This paper also concerns about mechanism, kinetic and hydrodynamic studies of anaerobic digestion for future application of the anaerobic baffled reactor for wastewater treatment.

Hassan, Siti Roshayu; Dahlan, Irvan

2013-09-01

177

Enhancing the Anaerobic Response  

PubMed Central

Proteome analysis, and more recently DNA chip technology, has led to the identification of a large number of genes that are implicated in the anaerobic response of plants. As a result, an increasingly complex picture of the response in terms of biochemical and regulatory processes is emerging. A challenge is to find out more about the function of these newly identified gene products, and how they contribute to flooding tolerance. Our approach has been to manipulate levels of candidate gene products (using sense and antisense constructs) in the model system Arabidopsis thaliana, combined with biochemical and phenotypic analysis of the resulting transgenic plants. PMID:12509332

DOLFERUS, RUDY; KLOK, ERIK JAN; DELESSERT, CHRISTIAN; WILSON, SARAH; ISMOND, KATHLEEN P.; GOOD, ALLEN G.; PEACOCK, W. JAMES; DENNIS, ELIZABETH S.

2003-01-01

178

Diversity of anaerobic halophilic microorganisms  

NASA Astrophysics Data System (ADS)

Life in the presence of high salt concentrations is compatible with life in the absence of oxygen. Halophilic and halotolerant anaerobic prokaryotes are found both in the archaeal and in the bacterial domain, and they display a great metabolic diversity. Many of the representatives of the Halobacteriales (Archaea), which are generally considered aerobes, have the potential of anaerobic growth. Some can use alternative electron acceptors such as nitrate, fumarate, dimethylsulfoxide or trimethylamine-N-oxide Halobacterium salinarum can also grow fermentatively on L-arginine, and bacteriorhodopsin-containing cells may even grow anaerobically, energized by light. Obligatory anaerobic halophilic methanogenic Archaea also exist. The bacterial domain contains many anaerobic halophiles, including sulfate reducers. There is also a group of specialized obligatory anaerobic Bacteria, phylogenetically clustering in the low G + C branch of the Firmicutes. Most representatives of this group (order Haloanaerobiales, families Haloanaerobiaceae and Halobacteroidaceae) are fermentative, using a variety of carbohydrates and amino acids. One species combines the potential for anaerobic growth at high salt concentrations with a preference for high temperatures. Others are homoacetogens; Acetohalobium arabaticum can grow anaerobically as a chemolithotroph, producing acetate from hydrogen and CO2. The Haloanaerobiales accumulate high concentrations of K+ and Cl- in their cytoplasm, thereby showing a strategy of salt adaptation similar to that used by the Halobacteriales. Recently a new representative of the Haloanaerobiales was isolated from bottom sediments of the Dead Sea (strain DSSe1), which grows anaerobically by oxidation of glycerol to acetate and CO2 while reducing selenate to selenite and elementary selenium. Other electron acceptors supporting anaerobic growth of this strain are nitrate and trimethylamine-N-oxide. The versatility of life at high salt concentrations with respect to the variety of substrates used, the types of dissimilatory metabolism, and the diversity of potential electron acceptors has important implications for the potential for life in hostile environments lacking oxygen and high in salt, implications that may also be relevant to astrobiology.

Oren, Aharon; Oremland, Roland S.

2000-12-01

179

The Histone Acetyltransferase p300 Regulates the Expression of Pluripotency Factors and Odontogenic Differentiation of Human Dental Pulp Cells  

PubMed Central

p300 is a well-known histone acetyltransferase (HAT) and coactivator that plays vital roles in many physiological processes. Despite extensive research on the involvement of p300 in the regulation of transcription in numerous cell lines, the roles of this protein in regulating pluripotency genes and odontogenic differentiation in human dental pulp cells (HDPCs) are poorly understood. To address this issue, we investigated the expression of OCT4, NANOG and SOX2 and the proliferation and odontogenic differentiation capacity of HDPCs following p300 overexpression. We found that p300 overexpression did not overtly affect the ability of HDPCs to proliferate. The overexpression of p300 upregulated the promoter activity and the mRNA and protein expression of NANOG and SOX2. The HAT activity of p300 appeared to partially mediate the regulation of these factors; indeed, when a mutant form of p300 lacking the HAT domain was overexpressed, the promoter activity and expression of NANOG and SOX2 decreased relative to p300 overexpression but was greater than in the control. Furthermore, we demonstrated that the mRNA levels of the odontogenic marker genes dentine matrix protein-1 (DMP-1), dentin sialophosphoprotein (DSPP), dentin sialoprotein (DSP), osteopontin (OPN) and osteocalcin (OCN) were significantly decreased in HDPCs overexpressing p300 cultured under normal culture conditions and increased in HDPCs inducted to undergo odontogenic differentiation. This finding was further confirmed by measuring levels of alkaline phosphatase (ALP) activity and assessing the formation of mineralized nodules. The HAT activity of p300 had no significant effect on odontogenic differentiation. p300 was recruited to the promoter regions of OCN and DSPP and might be acting as a coactivator to increase the acetylation of lysine 9 of histone H3 of OCN and DSPP. Collectively, our results show that p300 plays an important role in regulating the expression of key pluripotency genes in HDPCs and modifying odontogenic differentiation. PMID:25007265

Ning, Yanyang; Xu, Qiong

2014-01-01

180

A rare case of recurring calcifying epithelial odontogenic cyst in the maxillary sinus: a case report and literature review.  

PubMed

Calcifying epithelial odontogenic cyst (CEOC) is an odontogenic cyst with epithelial lining. CEOC is a rare entity that occurs in a wide age range, does not show any gender predilection, and accounts for only 1% of all jaw cysts. The lesion generally occurs in the region anterior to maxillary and mandibular molars and either intraosseously or extraosseusly. This entity might present as a cystic or solid lesion. Enucleation is the recommended treatment for a simple, unicystic CEOC. A case of recurring CEOC in the right maxilla antrum is presented here. The patient presented to the authors after postsurgical recurrence. The case was evaluated thoroughly, and the cyst was resolved. PMID:24064174

Karun, Vinayak; Mishra, Amit Kumar; Saikhedkar, Rashmi

2013-01-01

181

Adaptation and Antibiotic Tolerance of Anaerobic Burkholderia pseudomallei ? †  

PubMed Central

The Gram-negative bacterium Burkholderia pseudomallei is the etiological agent of melioidosis and is remarkably resistant to most classes of antibacterials. Even after months of treatment with antibacterials that are relatively effective in vitro, there is a high rate of treatment failure, indicating that this pathogen alters its patterns of antibacterial susceptibility in response to cues encountered in the host. The pathology of melioidosis indicates that B. pseudomallei encounters host microenvironments that limit aerobic respiration, including the lack of oxygen found in abscesses and in the presence of nitric oxide produced by macrophages. We investigated whether B. pseudomallei could survive in a nonreplicating, oxygen-deprived state and determined if this physiological state was tolerant of conventional antibacterials. B. pseudomallei survived initial anaerobiosis, especially under moderately acidic conditions similar to those found in abscesses. Microarray expression profiling indicated a major shift in the physiological state of hypoxic B. pseudomallei, including induction of a variety of typical anaerobic-environment-responsive genes and genes that appear specific to anaerobic B. pseudomallei. Interestingly, anaerobic B. pseudomallei was unaffected by antibacterials typically used in therapy. However, it was exquisitely sensitive to drugs used against anaerobic pathogens. After several weeks of anaerobic culture, a significant loss of viability was observed. However, a stable subpopulation that maintained complete viability for at least 1 year was established. Thus, during the course of human infection, if a minor subpopulation of bacteria inhabited an oxygen-restricted environment, it might be indifferent to traditional therapy but susceptible to antibiotics frequently used to treat anaerobic infections. PMID:21537012

Hamad, Mohamad A.; Austin, Chad R.; Stewart, Amanda L.; Higgins, Mike; Vazquez-Torres, Andres; Voskuil, Martin I.

2011-01-01

182

Arsenic, Anaerobes, and Autotrophy.  

NASA Astrophysics Data System (ADS)

That microbes have resistance to the toxic arsenic oxyanions arsenite [As(III)] and arsenate [As(V)] has been recognized for some time. More recently it was shown that certain prokaryotes can demonstrate As- dependent growth by conserving the energy gained from the aerobic oxidation of As(III) to As(V), or from the reduction of As(V) to As(III) under anaerobic conditions. During the course of our field studies of two alkaline, hypersaline soda lakes (Mono Lake and Searles Lake, CA) we have discovered several new anaerobic chemo- and photo-autotrophic bacteria that can center their energy gain around the redox reactions between As(III) and As(V). Alkalilimnicola ehrlichii, isolated from the water column of Mono Lake is a nitrate-respiring, As(III)-oxidizing chemoautotroph of the gamma-proteobacteria that has a highly flexible metabolism. It can function either as a facultative anaerobe or as a chemo-autotroph, or as a heterotroph (Hoeft et al., 2007). In contrast, strain MLMS-1 of the delta-proteobacteria was also isolated from Mono Lake, but to date is the first example of an obligate As(V)-respirer that is also an obligate chemo-autotroph, gaining its energy via the oxidation of sulfide to sulfate (Hoeft et al., 2004). Strain SLAS-1, isolated from salt-saturated Searles Lake is a member of the Halananerobiales, and can either grow as a heterotroph (lactate e-donor) or chemo- autotroph (sulfide e-donor) while respiring As(V). The fact that it can achieve this feat at salt-saturation (~ 340 g/L) makes it a true extremophile (Oremland et. al., 2005). Finally, strain PHS-1 isolated from a hot spring on Paoha island in Mono Lake is the first example of a photosynthetic bacterium of the gamma- proteobacteria able to link its growth to As(III)-dependent anoxygenic photosynthesis (Kulp et al., 2008). These novel microbes give us new insights into the evolution of arsenic-based metabolism and their role in the biogeochemical cycling of this toxic element. Hoeft, S.E., et al. 2007. Int. J. Syst. Evol. Microbiol. 57: 514 - 512. Hoeft, S.E, et al. 2004. Appl. Environ. Microbiol. 70: 2741 - 2747. Oremland, R.S., et al. 2005. Science 308: 1305 - 1308. Kulp, T.R. et al. 2008. Science 321: 967 - 970.

Oremland, R. S.

2008-12-01

183

Anaerobic Metabolism of Indoleacetate  

PubMed Central

The anaerobic metabolism of indoleacetate (indole-3-acetic acid [IAA]) in the denitrifying betaproteobacterium Azoarcus evansii was studied. The strain oxidized IAA completely and grew with a generation time of 10 h. Enzyme activities that transformed IAA were present in the soluble cell fraction of IAA-grown cells but were 10-fold downregulated in cells grown on 2-aminobenzoate or benzoate. The transformation of IAA did not require molecular oxygen but required electron acceptors like NAD+ or artificial dyes. The first products identified were the enol and keto forms of 2-oxo-IAA. Later, polar products were observed, which could not yet be identified. The first steps likely consist of the anaerobic hydroxylation of the N-heterocyclic pyrrole ring to the enol form of 2-oxo-IAA, which is catalyzed by a molybdenum cofactor-containing dehydrogenase. This step is probably followed by the hydrolytic ring opening of the keto form, which is catalyzed by a hydantoinase-like enzyme. A comparison of the proteome of IAA- and benzoate-grown cells identified IAA-induced proteins. Owing to the high similarity of A. evansii with strain EbN1, whose genome is known, we identified a cluster of 14 genes that code for IAA-induced proteins involved in the early steps of IAA metabolism. These genes include a molybdenum cofactor-dependent dehydrogenase of the xanthine oxidase/aldehyde dehydrogenase family, a hydantoinase, a coenzyme A (CoA) ligase, a CoA transferase, a coenzyme B12-dependent mutase, an acyl-CoA dehydrogenase, a fusion protein of an enoyl-CoA hydratase and a 3-hydroxyacyl-CoA dehydrogenase, a beta-ketothiolase, and a periplasmic substrate binding protein for ABC transport as well as a transcriptional regulator of the GntR family. Five predicted enzymes form or act on CoA thioesters, indicating that soon after the initial oxidation of IAA and possibly ring opening, CoA thioesters are formed, and the carbon skeleton is rearranged, followed by a CoA-dependent thiolytic release of another CoA thioester. We propose a scheme of an anaerobic IAA metabolic pathway that ultimately leads to 2-aminobenzoyl-CoA or benzoyl-CoA. PMID:22447903

Ebenau-Jehle, Christa; Thomas, Markus; Scharf, Gernot; Kockelkorn, Daniel; Knapp, Bettina; Schuhle, Karola; Heider, Johann

2012-01-01

184

Anaerobic metabolism of indoleacetate.  

PubMed

The anaerobic metabolism of indoleacetate (indole-3-acetic acid [IAA]) in the denitrifying betaproteobacterium Azoarcus evansii was studied. The strain oxidized IAA completely and grew with a generation time of 10 h. Enzyme activities that transformed IAA were present in the soluble cell fraction of IAA-grown cells but were 10-fold downregulated in cells grown on 2-aminobenzoate or benzoate. The transformation of IAA did not require molecular oxygen but required electron acceptors like NAD(+) or artificial dyes. The first products identified were the enol and keto forms of 2-oxo-IAA. Later, polar products were observed, which could not yet be identified. The first steps likely consist of the anaerobic hydroxylation of the N-heterocyclic pyrrole ring to the enol form of 2-oxo-IAA, which is catalyzed by a molybdenum cofactor-containing dehydrogenase. This step is probably followed by the hydrolytic ring opening of the keto form, which is catalyzed by a hydantoinase-like enzyme. A comparison of the proteome of IAA- and benzoate-grown cells identified IAA-induced proteins. Owing to the high similarity of A. evansii with strain EbN1, whose genome is known, we identified a cluster of 14 genes that code for IAA-induced proteins involved in the early steps of IAA metabolism. These genes include a molybdenum cofactor-dependent dehydrogenase of the xanthine oxidase/aldehyde dehydrogenase family, a hydantoinase, a coenzyme A (CoA) ligase, a CoA transferase, a coenzyme B(12)-dependent mutase, an acyl-CoA dehydrogenase, a fusion protein of an enoyl-CoA hydratase and a 3-hydroxyacyl-CoA dehydrogenase, a beta-ketothiolase, and a periplasmic substrate binding protein for ABC transport as well as a transcriptional regulator of the GntR family. Five predicted enzymes form or act on CoA thioesters, indicating that soon after the initial oxidation of IAA and possibly ring opening, CoA thioesters are formed, and the carbon skeleton is rearranged, followed by a CoA-dependent thiolytic release of another CoA thioester. We propose a scheme of an anaerobic IAA metabolic pathway that ultimately leads to 2-aminobenzoyl-CoA or benzoyl-CoA. PMID:22447903

Ebenau-Jehle, Christa; Thomas, Markus; Scharf, Gernot; Kockelkorn, Daniel; Knapp, Bettina; Schühle, Karola; Heider, Johann; Fuchs, Georg

2012-06-01

185

Immunohistochemical comparison of cyclin D1 and P16 in odontogenic keratocyst and unicystic ameloblastoma  

PubMed Central

Background: The different growth mechanism and biologic behavior of the odontogenic keratocyst (OKC) compared to other odontogenic cysts might be related to the proliferating capacity of its epithelium. In this study, the aim was to evaluate and compare the distribution and staining intensity of P16 and cyclin D1 in OKC and unicystic ameloblastoma (UA). Materials and Methods: In this descriptive analytic study, hematoxylin- and eosin-stained slides of OKCs and UAs available from the archives of the oral pathology laboratory of the Esfahan School of Dentistry were examined. Twenty-five noninflamed solitary odontogenic keratocysts and 25 unicystic ameloblastomas (of either type) were selected and stained immunohistochemically. Distribution and staining intensity score (SID score) for P16- and cyclin D1-positive cells was calculated in both groups. Results were analyzed statistically with Wilcoxon, Friedman, and Mann-Whitney tests; P < 0.05 was considered significant. Results: The highest expression of Cyclin D1-positive cells was seen in the suprabasal layer of keratocysts (P < 0.05) and in the peripheral layer of UAs (P < 0.05). Likewise, the highest expression of P16-positive cells was observed in the basal and suprabasal layers of keratocysts (P > 0.05) and central portions of UAs (P > 0.05). Expression of Cyclin D1 was higher in UAs compared to keratocyts (P < 0.05), although P16 did not show a significant difference between the two study groups (P > 0.05). Conclusion: Cyclin D1 did show a higher staining intensity in UAs compared to the keratocysts, although the expression of P16 was similar in the studied groups. The invasive growth of OKC might be related to the state of expression of cyclin D1 and P16 in the epithelium of this cyst. PMID:23946733

Razavi, Seyed Mohammad; Poursadeghi, Hamid; Aminzadeh, Atousa

2013-01-01

186

The phenomenon of granulation of anaerobic sludge  

Microsoft Academic Search

Successful high-rate anaerobic wastewater treatment can only be accomplished when the slowgrowing anaerobic biomass is efficiently held back in the anaerobic treatment system. This biomass retention can be achieved in various ways including immobilization of the organisms on fixed materials and immobilization on mobile support materials: in the latter case, combined with settling of the anaerobic sludge aggregates.This dissertation focuses

L. W. Hulshoff Pol

1989-01-01

187

Bone marrow stromal cell paracrine factors direct osteo/odontogenic differentiation of dental pulp cells.  

PubMed

Growth factors play an important role in osteo/odontogenic differentiation of human dental pulp cells (hDPCs). The aim of this in vitro study was to compare the biological effects of recombinant human growth differentiation factor 5 (rhGDF-5) alone and a cocktail of soluble growth factors (conditioned medium) released from human bone marrow mesenchymal stem cells (hBMMSCs) on the morphology, proliferation and osteo/odontogenic differentiation potential of hDPCs. Passage 4 hDPCs were harvested for culture in four different media: (a) DMEM with 10% FBS, (b) odontogenic induction medium (OM), (c) OM plus 500?ng/mL rhGDF-5, and (d) OM plus conditioned medium (CM). Morphological changes at 48 and 120?h were determined by crystal violet staining. The proliferation rates at 3, 24, 48, and 120?h were assayed by MTT. Using real-time reverse transcription-polymerase chain reaction (RT-PCR), the mRNA levels of dentin sialophosphoprotein (DSPP), dentin matrix protein 1 (DMP1), collagen type I (Col 1), Runt-related transcription factor 2 (Cbfa1/Runx2), alkaline phosphatase (ALP), osteocalcin (OC), ?3 tubulin (TUBB3), glial cell-derived neurotrophic factor (GDNF), angiopoietin-1 (Ang1), and vascular endothelial growth factor A (VEGFA), were determined at 2, 5, and 9 days. Protein expression of dental sialoprotein (DSP), DMP1, OC, and TUBB3 was recorded at 5 days, using western blot and immunocytochemistry. The effect of the different culture media on mineralization was determined by ALP staining at day 5 and Alizarin red S staining at days 7 and 14. In response to the different culture media, the shape of the hDPCs varied from spindled to polygonal and cuboidal. CM inhibited the cellular proliferation rate, while rhGDF-5 had no effect at early time points, but promoted cellular proliferation at 120?h of culture. In the CM group, the mRNA levels of Cbfa1/Runx2, Col 1, ALP, VEGFA, Ang1, and TUBB3 decreased and the levels of GDNF and OC increased. The mRNA levels of DSPP and DMP1 were inconsistent at the time points evaluated. The staining assays also demonstrated that compared with the other groups, the CM group exhibited lower expression of ALP and higher mineralization levels. Protein expression of DSP, DMP1, OC, and TUBB3 was pronounced by the CM-treated cells. It is concluded that under these in vitro conditions, CM released from hBMMSCs have a greater osteo/odontogenic inductive effect on hDPCs than rhGDF-5. PMID:24813721

Al-Sharabi, Niyaz; Xue, Ying; Fujio, Masahito; Ueda, Minoru; Gjerde, Cecilie; Mustafa, Kamal; Fristad, Inge

2014-11-01

188

Orbital complications due to an acute odontogenic focus in a child. A case report.  

PubMed

The full clinical manifestations of complications due to odontogenic foci are rarely seen in daily dental practice and can take a clinically foudroyant course of development in young people owing to anatomic conditions, as demonstrated in this clinical case in a 12-year-old girl. Endodontic treatment of the first right upper molar was started owing to increasing toothache and swelling of fossa canina and the periorbital region. During the course of treatment, the patient exhibited an acute increase in orbital inflammation, which required immediate surgical intervention with postsurgical intravenous antibiotic administration. This case should serve to emphasize the crucial requirement for intensive attention to orbital symptoms after dental procedures. PMID:19101481

Wysluch, Andreas; Maurer, Peter; Ast, Jens; Kunkel, M

2009-01-01

189

Report of a Rare Case of an Odontogenic Myxoma of the Maxilla and Review of Literature  

PubMed Central

Odontogenic myxoma (OM) is a mesenchymal tissue benign neoplasia, being relatively rare which is almost exclusively seen in tooth-bearing areas. OM commonly occurs in the 2nd and 3rd decade and the mandible is involved more commonly than the maxilla. The lesion often grows without symptoms and presents as a painless swelling. Radiographically, the myxoma appears as a unilocular or multilocular radiolucency. This article presents a rare case of OM occurring in the maxilla of a 28-year-old female patient with a brief review of the literature. PMID:25031907

Manjunath, SM; Gupta, AA; Swetha, P; Moon, NJ; Singh, S; Singh, A

2014-01-01

190

PCB breakdown by anaerobic microorganisms  

SciTech Connect

Recently, altered PCB cogener distribution patterns observed in anaerobic sediment samples from the upper Hudson River are being attributed to biologically mediated reductive dechlorination. The authors report their successful demonstration of biologically mediated reductive dechlorination of an Aroclor mixture. In their investigation, they assessed the ability of microorganisms from PCB-contaminated Hudson River sediments (60-562 ppm PCBs) to dechlorinate Aroclor 1242 under anaerobic conditions by eluting microorganisms from the PCB- contaminated sediments and transferring them to a slurry of reduced anaerobic mineral medium and PCB-free sediments in tightly stoppered bottles. They observed dechlorination to be the most rapid at the highest PCB concentration tried by them.

Not Available

1989-03-01

191

Dance--Aerobic and Anaerobic.  

ERIC Educational Resources Information Center

This article defines and explains aerobic exercise and its effects on the cardiovascular system. Various studies on dancers are cited indicating that dance is an anaerobic activity with some small degree of aerobic benefit. (DF)

Cohen, Arlette

1984-01-01

192

In Vitro Activity of Ceftazidime-NXL104 against 396 Strains of ?-Lactamase-Producing Anaerobes ?  

PubMed Central

NXL104, a novel ?-lactamase inhibitor, was tested at a constant concentration of 4 ?g/ml in combination with ceftazidime (CAZ), with and without added metronidazole, against 396 ?-lactamase-producing strains of anaerobic bacteria. MIC50/MIC90 values for Bacteroides fragilis and the B. fragilis group were 8/16 and 64/>128 ?g/ml, respectively. Although CAZ-NXL104 had limited activity against most anaerobic strains, in combination with metronidazole it shows potential for treating mixed infections involving resistant Enterobacteriaceae and anaerobes. PMID:21537015

Citron, Diane M.; Tyrrell, Kerin L.; Merriam, Vreni; Goldstein, Ellie J. C.

2011-01-01

193

BIOREMEDIATION: Anaerobes to the Rescue  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required: Polluted groundwater systems are very difficult to clean up. In his Perspective, Lovley charts recent advances towards in situ bioremediation of such systems using anaerobic organisms. Such organisms, which naturally exist in soils, may assist in cleaning up hydrocarbons, chlorinated pollutants, and metals. The author concludes that anaerobic strategies are promising but that substantial research remains to be done before any of them can be adopted for routine application.

Derek R. Lovley (University of Massachusetts;Department of Microbiology)

2001-08-24

194

Anaerobic bacteria that dechlorinate perchloroethene.  

PubMed Central

In this study, we identified specific cultures of anaerobic bacteria that dechlorinate perchlorethene (PCE). The bacteria that significantly dechlorinated PCE were strain DCB-1, an obligate anaerobe previously shown to dechlorinate chlorobenzoate, and two strains of Methanosarcina. The rate of PCE dechlorination by DCB-1 compared favorably with reported rates of trichloroethene bio-oxidation by methanotrophs. Even higher PCE dechlorination rates were achieved when DCB-1 was grown in a methanogenic consortium. PMID:3426224

Fathepure, B Z; Nengu, J P; Boyd, S A

1987-01-01

195

Correlation Between Collagen Fibers and Radiographic Patterns of Keratocystic Odontogenic Tumour  

PubMed Central

Background: WHO has recently renamed odontogenic keratocyst as keratocystic odontogenic tumour (KCOT) depending on its tumour like behaviour. Aim: To quantitate and qualitate different types of collagen fibers in KCOT using picrosirius red stain under polarising microscopy and to correlate with different radiographic patterns of KCOT to elucidate its biological behaviour in order to determine whether all KCOTs behave like a tumour. Materials and Methods: Sixty histopathologically confirmed cases of KCOT were selected and stained histochemically using picrosirius red and examined under polarising microscope to evaluate colour of collagen fibers in the wall. Radiographic analysis of all the cases were also carried out and correlated with type of collagen of fibers. Results: Greenish yellow collagen fibers were present statistically significantly more in multilocular KCOT and KCOT with multiple radiolucencies (both syndromic and non-syndromic) as compare to unilocular whereas orange red were significantly more in unilocular variety. Syndromic variety showed significantly higher number of greenish yellow collagen fibers than non-syndromic variety. Conclusion: Quality, organization and packing of collagen fibers of unilocular type is different than other radiographic patterns which accounts for difference in biological behaviour of these lesion, so we conclude that aggressive treatment should be reserved for selected cases. PMID:25302259

Shetty, Sujan; Patil, Prashant; Sethi, Neerja; Singh, Abhayjeet; Raghunandan, BN

2014-01-01

196

Utility of cell block in the cytological preoperative diagnosis of keratocystic odontogenic tumor.  

PubMed

In most cases involving jaw lesions, a biopsy and a histopathological analysis are necessary to establish the final diagnosis. However, biopsy may be a complex procedure at some maxillomandibular sites, and some systemic conditions could contraindicate the procedure. Thus, a search for new, less invasive techniques, which could eventually replace biopsy and simplify the diagnostic process, would benefit both professionals and patients. The aim of this study was to evaluate the cell block technique, prepared from the aspiration of luminal contents, in the preoperative diagnosis of keratocystic odontogenic tumors (KCOT). From 135 cases of lesions aspirated and processed by the cell block technique, we selected those containing keratin. In all cases selected, histological diagnosis was based on surgical biopsy. From 20 cases containing keratin in the cytological analyses, 19 were KCOTs and one was an orthokeratinized odontogenic cyst (OOC). In all KCOT cases, we observed the presence of parakeratin, even in those with intense inflammation. In the cytological analysis of the OOC, parakeratin was not observed. In conclusion, there is strong evidence that KCOT can be confidently diagnosed preoperatively by cytological analyses of lesions punctured and processed by the cell block technique. PMID:24433974

Rivero, Elena Riet Correa; Grando, Liliane Janete; de Oliveira Ramos, Grasieli; da Silva Belatto, Maria Fernanda; Daniel, Filipe Ivan

2014-04-01

197

Notch signaling and ghost cell fate in the calcifying cystig odontogenic tumor  

PubMed Central

Notch signaling is an evolutionarily conserved mechanism that enables adjacent cells to adopt different fates. Ghost cells (GCs) are anucleate cells with homogeneous pale eosinophilic cytoplasm and very pale to clear central areas (previous nucleus sites). Although GCs are present in a variety of odontogenic lesions notably the calcifying cystic odontogenic tumor (GCOT), their nature and process of formation remains elusive. The aim of this study was to investigate the role of Notch signaling in the cell fate specification of GCs in CCOT. Immunohistochemical staining for four Notch receptors (Notch1, Notch2, Notch3 and Notch4) and three ligands (Jagged1, Jagged2 and Delta1) was performed on archival tissues of five CCOT cases. Level of positivity was quantified as negative (0), mild (+), moderate (2+) and strong (3+). Results revealed that GCs demonstrated overexpression for Notch1 and Jagged1 suggesting that Notch1Jagged1 signaling might serve as the main transduction mechanism in cell fate decision for GCs in CCOT. Protein localizations were largely membranous and/or cytoplasmic. Mineralized GCs also stained positive implicating that the calcification process might be associated with upregulation of these molecules. The other Notch receptors and ligands were weak to absent in GCs and tumoral epithelium. Stromal endothelium and fibroblasts were stained variably positive. PMID:22027644

2011-01-01

198

Myofibroblasts in stroma of odontogenic cysts and tumors can contribute to variations in the biological behavior of lesions.  

PubMed

Stromal myofibroblasts (MF) have the potential to facilitate progression of neoplastic epithelial lesions that could contribute to their biological behavior. To assess immunohistochemically the frequency of stromal MF in different odontogenic cysts and tumors and correlate it to their aggressive biological behavior. The study included cases of dentigerous cyst (DC, n = 7), odontogenic keratocyst-parakeratinized type (OKC-P, n = 8), orthokeratinized type (OKC-O, n = 9), ameloblastic fibroma/fibro-odontoma (AMF/O, n = 11), unicystic ameloblastoma (UAM, n = 6), and solid ameloblastoma (SAM, n = 7). Cases of oral squamous cell carcinoma (SCC, n = 5) served as control. Myofibroblast frequency was assessed as the number of alpha smooth muscle actin (alphaSMA)-positive stromal cells in 10 high-power fields, presented as the mean number of positive cells per field. Counts showed that mean number of positive cells in OKC-P (25.7+/-11.4) was significantly higher than in DC (8.7+/-11.6) (p = 0.024) and in SAM (29+/-7) it was significantly higher than in UAM (14.9+/-4.9) and AMF/O (5.6+/-7.5) (p < 0.001). Counts in OKC-P and SAM were not significantly different from SCC (21.3+/-5.3) (p > 0.05). The high frequency of stromal MF in known aggressive odontogenic lesions, such as OKC-P and SAM, implies that MF can contribute to the biological behavior of these odontogenic lesions. Various pharmacological agents that control stromal MF can be used as an aid to reduce extensive and mutilating surgery in cases of remarkably aggressive odontogenic lesions. PMID:16139563

Vered, Marilena; Shohat, Izhar; Buchner, Amos; Dayan, Dan

2005-11-01

199

Ki-67 and MCM-2 in Dental Follicle and Odontogenic Cysts: The Effects of Inflammation on Proliferative Markers  

PubMed Central

The aim of this study was to investigate whether there is any association between inflammation and the expression of markers of cell cycle entry (Ki-67 and MCM-2) in dental follicle (DF) of asymptomatic impacted teeth and odontogenic cysts. The study consisted of 70 DFs and 20 odontogenic cysts (radicular cyst (RC), dentigerous cyst (DC) and keratocytic odontogenic tumor (KCOT) located at posterior mandibular region. Histological findings of inflammation for all specimen and mucous cell prosoplasia, squamous metaplasia, glandular epithelium for all DFs were stained with hematoxyline and eosin, periodic acid schiff, alcian blue, and mucin. Epithelial cell proliferation was determined by using immunohistochemical labeling for Ki-67 and MCM-2. The histologic examinations showed 16% mucous cell prosoplasia, 54% squamous metaplasia, 20% glandular epithelium, 37% inflammation. Inflammation was detected in all RCs and %62 in DF, %43 in DC and KCOT. Positive correlation was found between the inflammation of DF and odontogenic cysts (P < 0.01). The mean Ki-67 and MCM-2 expressions were found 9, 64 ± 5, 99 and 6, 34 ± 3, 81 in DF, 11, 85 ± 9, 01 and 13, 6 ± 9, 94 in odontogenic cysts, respectively. While the mean Ki-67 expressions were statistically significant in DF and KCOT (P < 0.01), MCM-2 were significant in RC and KCOT (P < 0.01). MCM-2 expresion in RCs were statistically significant than KCOT (P < 0.01). The results of this study indicated that the higher MCM-2 expressions in RC than the KCOT might be related to the inflammation and this protein might be more sensitive to inflammation. PMID:22778705

Guler, Nurhan; Comunoglu, Nil; Cabbar, Fatih

2012-01-01

200

Drug Targets and Mechanisms of Resistance in the Anaerobic Protozoa  

PubMed Central

The anaerobic protozoa Giardia duodenalis, Trichomonas vaginalis, and Entamoeba histolytica infect up to a billion people each year. G. duodenalis and E. histolytica are primarily pathogens of the intestinal tract, although E. histolytica can form abscesses and invade other organs, where it can be fatal if left untreated. T. vaginalis infection is a sexually transmitted infection causing vaginitis and acute inflammatory disease of the genital mucosa. T. vaginalis has also been reported in the urinary tract, fallopian tubes, and pelvis and can cause pneumonia, bronchitis, and oral lesions. Respiratory infections can be acquired perinatally. T. vaginalis infections have been associated with preterm delivery, low birth weight, and increased mortality as well as predisposing to human immunodeficiency virus infection, AIDS, and cervical cancer. All three organisms lack mitochondria and are susceptible to the nitroimidazole metronidazole because of similar low-redox-potential anaerobic metabolic pathways. Resistance to metronidazole and other drugs has been observed clinically and in the laboratory. Laboratory studies have identified the enzyme that activates metronidazole, pyruvate:ferredoxin oxidoreductase, to its nitroso form and distinct mechanisms of decreasing drug susceptibility that are induced in each organism. Although the nitroimidazoles have been the drug family of choice for treating the anaerobic protozoa, G. duodenalis is less susceptible to other antiparasitic drugs, such as furazolidone, albendazole, and quinacrine. Resistance has been demonstrated for each agent, and the mechanism of resistance has been investigated. Metronidazole resistance in T. vaginalis is well documented, and the principal mechanisms have been defined. Bypass metabolism, such as alternative oxidoreductases, have been discovered in both organisms. Aerobic versus anaerobic resistance in T. vaginalis is discussed. Mechanisms of metronidazole resistance in E. histolytica have recently been investigated using laboratory-induced resistant isolates. Instead of downregulation of the pyruvate:ferredoxin oxidoreductase and ferredoxin pathway as seen in G. duodenalis and T. vaginalis, E. histolytica induces oxidative stress mechanisms, including superoxide dismutase and peroxiredoxin. The review examines the value of investigating both clinical and laboratory-induced syngeneic drug-resistant isolates and dissection of the complementary data obtained. Comparison of resistance mechanisms in anaerobic bacteria and the parasitic protozoa is discussed as well as the value of studies of the epidemiology of resistance. PMID:11148007

Upcroft, Peter; Upcroft, Jacqueline A.

2001-01-01

201

Bacterial drug tolerance under clinical conditions is governed by anaerobic adaptation but not anaerobic respiration.  

PubMed

Noninherited antibiotic resistance is a phenomenon whereby a subpopulation of genetically identical bacteria displays phenotypic tolerance to antibiotics. We show here that compared to Escherichia coli, the clinically relevant genus Burkholderia displays much higher levels of cells that tolerate ceftazidime. By measuring the dynamics of the formation of drug-tolerant cells under conditions that mimic in vivo infections, we show that in Burkholderia bacteria, oxygen levels affect the formation of these cells. The drug-tolerant cells are characterized by an anaerobic metabolic signature and can be eliminated by oxygenating the system or adding nitrate. The transcriptome profile suggests that these cells are not dormant persister cells and are likely to be drug tolerant as a consequence of the upregulation of anaerobic nitrate respiration, efflux pumps, ?-lactamases, and stress response proteins. These findings have important implications for the treatment of chronic bacterial infections and the methodologies and conditions that are used to study drug-tolerant and persister cells in vitro. PMID:25049258

Hemsley, Claudia M; Luo, Jamie X; Andreae, Clio A; Butler, Clive S; Soyer, Orkun S; Titball, Richard W

2014-10-01

202

Bacterial Drug Tolerance under Clinical Conditions Is Governed by Anaerobic Adaptation but not Anaerobic Respiration  

PubMed Central

Noninherited antibiotic resistance is a phenomenon whereby a subpopulation of genetically identical bacteria displays phenotypic tolerance to antibiotics. We show here that compared to Escherichia coli, the clinically relevant genus Burkholderia displays much higher levels of cells that tolerate ceftazidime. By measuring the dynamics of the formation of drug-tolerant cells under conditions that mimic in vivo infections, we show that in Burkholderia bacteria, oxygen levels affect the formation of these cells. The drug-tolerant cells are characterized by an anaerobic metabolic signature and can be eliminated by oxygenating the system or adding nitrate. The transcriptome profile suggests that these cells are not dormant persister cells and are likely to be drug tolerant as a consequence of the upregulation of anaerobic nitrate respiration, efflux pumps, ?-lactamases, and stress response proteins. These findings have important implications for the treatment of chronic bacterial infections and the methodologies and conditions that are used to study drug-tolerant and persister cells in vitro. PMID:25049258

Hemsley, Claudia M.; Luo, Jamie X.; Andreae, Clio A.; Butler, Clive S.; Soyer, Orkun S.

2014-01-01

203

PILOT ANAEROBIC BIOLOGICAL TREATMENT OF PULP MILL EVAPORATOR FOUL CONDENSATE  

EPA Science Inventory

The performance of three new anaerobic biological treatment technologies were compared and evaluated. Data were obtained from the operation of pilot plants representative of the anaerobic filter, anaerobic upflow sludge bed, and anaerobic fluidized bed. A review of recent literat...

204

Anaerobic degradation and toxicity of commercial cationic surfactants in anaerobic screening tests  

Microsoft Academic Search

Anaerobic biodegradability and toxicity on anaerobic bacteria of di(hydrogenated tallow) dimethyl ammonium chloride (DHTDMAC) and two esterquats have been investigated. A batch test system containing municipal digester solids as a source of anaerobic bacteria, based on the method proposed by the ECETOC, has been applied. To evaluate the potential toxicity of such surfactants on anaerobic sludge, a co-substrate, an easily

M. T. Garc??a; E. Campos; J. Sánchez-Leal; I. Ribosa

2000-01-01

205

Arsenic, Anaerobes, and Astrobiology  

NASA Astrophysics Data System (ADS)

Arsenic is an element best known for its highly poisonous nature, so it is not something one would associate with being a well-spring for life. Yet discoveries made over the past two decades have delineated that not only are some microbes resistant to arsenic, but that this element's primary redox states can be exploited to conserve energy and support prokaryotic growth ('arsenotrophy') in the absence of oxygen. Hence, arsenite [As(III)] can serve as an electron donor for chemo- or photo-autotrophy while arsenate [As(V)] will serve as an electron acceptor for chemo-heterotrophs and chemo-autotrophs. The phylogenetic diversity of these microbes is broad, encompassing many individual species from diverse taxonomic groups in the Domain Bacteria, with fewer representatives in the Domain Archaea. Speculation with regard to the evolutionary origins of the key functional genes in anaerobic arsenic transformations (arrA and arxA) and aerobic oxidation (aioB) has led to a disputation as to which gene and function is the most ancient and whether arsenic metabolism extended back into the Archaean. Regardless of its origin, robust arsenic metabolism has been documented in extreme environments that are rich in their arsenic content, such as hot springs and especially hypersaline soda lakes associated with volcanic regions. Searles Lake, CA is an extreme, salt-saturated end member where vigorous arsenic metabolism occurs, but there is no detectable sulfate-reduction or methanogenesis. The latter processes are too weak bio-energetically to survive as compared with arsenotrophy, and are also highly sensitive to the abundance of borate ions present in these locales. These observations have implications with respect to the search for microbial life elsewhere in the Solar System where volcanic-like processes have been operative. Hence, because of the likelihood of encountering dense brines in the regolith of Mars (formed by evapo-concentration) or beneath the ice layers of Europa, Ganymede, Titan or Enceladus (formed by cryo-concentration), arsenotrophy could serve as a credible means of microbial energy conservation. Regrettably, the direct search for arsenic biomarkers is restricted because only one stable isotope exists (75As), which rules out the use of stable isotopic ratios in this regard. However, antimony oxyanions often co-occur with arsenic in the environment. Its two stable isotopes (123Sb and 121Sb) hold the potential to be exploited as a proxy isotopic biomarker for the fingerprint of microbial arsenotrophy. Whether such an approach is feasible needs to be investigated.

Stolz, J. F.; Oremland, R. S.; Switzer Blum, J.; Hoeft, S. E.; Baesman, S. M.; Bennett, S.; Miller, L. G.; Kulp, T. R.; Saltikov, C.

2013-12-01

206

Assessment of the anaerobic biodegradability of macropollutants  

Microsoft Academic Search

A variety of test procedures for determination of anaerobic biodegradability have been reported. This paper reviews the methods developed for determination of anaerobic biodegradability of macro-pollutants. Main focus is paid to the final mineralization of organic compounds and the methane potential of compounds. Hydrolysis of complex substrates is also discussed. Furthermore, factors important for anaerobic biodegradation are shortly discussed.

Irini Angelidaki; Wendy Sanders

2004-01-01

207

Module 12: Biogas/Anaerobic Digesters  

NSDL National Science Digital Library

Eastern Iowa Community College provides this learning module to teach students anaerobic digester basics, the benefits of anaerobic digesters, the anaerobic digester process, and a variety of related topics. Users can download a zip file in which they will find a syllabus, student handouts, a quiz, and 55 slide PowerPoint presentation.

2014-09-02

208

[Descriptive and immunohistochemical study of ghost cell keratinization in the calcifying odontogenic cyst].  

PubMed

The calcifying odontogenic cyst (COC) or Gorlin cyst is a rare and benign lesion most often intraosseous, although an appreciable number of cases are peripheral. Two histologic entities are described, one being cystic and the other neoplastic. The cystic type may occur as three variants. The occurrence of ghost cells, although shared with calcifying epithelioma of Malherbe, craniopharyngioma and other odontogenic tumors, represents the most conspicuous feature of the COC. Ghost cells are so called because they stain only faintly with common dies, including eosin. Although seldom studied, it is claimed that ghost cells are keratinized. However, this hypothesis is not universally accepted since electron microscopic studies give evidence that ultrastructural features of ghost cells differ from what is observed during the keratinizing process of the epidermis and oral mucosae. The present study, dealing with one case of COC, combines two complementary techniques: one a Rhodamine B keratin specific staining method and the other an immunohistochemical technique based on the use of a primary antiserum directed against high molecular weight keratins. With the Rhodamine B method, ghost cells and orthokeratinized cells of control gingiva are strongly stained while intermediate cells of the COC are less prominent. On the other hand, with the immunohistochemical technique, intermediate mediate cells of the COC are less prominent. On the other hand, with the immunohistochemical technique, intermediate cells of the COC and high level cells of control epithelium react strongly. Ghost cells of the COC are only faintly labelled and orthokeratinized cells of the control gingiva remain unlabelled. In combination with previous histochemical studies, these results confirm the occurrence of a keratinizing process.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2426250

Monteil, R A; Bauduin, D; Marcelet, B

1986-06-01

209

The Anaerobic Digestion of Organic  

E-print Network

occurs naturally in landfills that contain organic waste, such as food scraps, paper products, and yardThe Anaerobic Digestion of Organic Municipal Solid Waste in California, these energy alternatives could provide a number of benefits, including reducing the United States' dependence

Iglesia, Enrique

210

Aerobic versus anaerobic wastewater treatment  

SciTech Connect

Biological wastewater treatment facilities are designed to emulate the purification process that occurs naturally in rivers, lakes and streams. In the simulated environment, conditions are carefully manipulated to spur the degradation of organic contaminants and stabilize the residual sludge. Whether the treatment process is aerobic or anaerobic is determined by a number of factors, including the composition of the wastewater, the degree of stabilization required for environmental compliance and economic viability. Because anaerobic digestion is accomplished without oxygen in a closed system, it is economical for pretreatment of high-strength organic sludge. Before the effluent can be discharged, however, followup treatment using an aerobic process is required. Though it has the drawback of being energy intensive, aerobic processing, the aeration of organic sludges in an open tank, is the primary method for treatment of industrial and municipal wastewater. Aerobic processes are more stable than anaerobic approaches and can be done rather simply, particularly with trickling filters. Gradually, the commercialization of modular systems that are capable of aerobic and anaerobic digestion will blur the distinctions between the two processes. Systems that boast those capabilities are available now.

Robinson, D.G.; White, J.E.; Callier, A.J. [Burns and McDonnell Engineering Co., Kansas City, MO (United States)

1997-04-01

211

Comparison of antioxidant enzymes activity and the concentration of uric acid in the saliva of patients with oral cavity cancer, odontogenic cysts and healthy subjects.  

PubMed

Chronic inflammation is related to oxidative stress and is still believed to be the cause of carcinogenesis. Patients with oral cavity cancer (OCC) exhibited lower total antioxidant capacity, uric acid (UA) concentration, salivary peroxidise (SPO) and superoxide dismutase (SOD) activity in their saliva than did healthy subjects. This could be a risk factor for tumour induction. Odontogenic cysts also arise in response to locally acting proinflammatory factors, for example, a gangrenous tooth. Furthermore, cyst development is accompanied by chronic inflammation. There are some reports in the literature concerning primary tumours such as squamous cell carcinomas arising from odontogenic cysts. The reason for this transformation is still unknown. The aim of this study was to compare the status of the antioxidant defence system in the saliva of the group with odontogenic cysts and OCC with that of the healthy control. Saliva samples were collected in the morning. SOD, SPO activity and UA concentration were determined using standard methods. Patients with odontogenic cysts and OCC exhibited lower activity of major antioxidants in their saliva (SPO, UA) than did healthy people. SOD activity and age are the main factors that distinguish these diseases. Discriminant function analysis showed that once data such as antioxidant status of saliva, age and smoking status are known 80% cases can be correctly classified as healthy, 80% as having odontogenic cysts and 40% as cancerous. To conclude, the decrease in concentrations of major antioxidants in the saliva of patients with cysts may increase the risk of neoplastic transformation especially in advanced age. PMID:21501233

Giebu?towicz, Joanna; Wroczy?ski, Piotr; Samolczyk-Wanyura, Danuta

2011-10-01

212

Anaerobic Fecal Flora in Healthy Breast-Fed Turkish Babies Born by Different Methods  

Microsoft Academic Search

The aim of this study is to determine the anaerobic fecal flora of 40 newborn, full-term healthy Turkish babies during 1 month and to find the difference of the flora depending on the manner of birth. Fecal samples of 15 newborn girls and 25 newborn boys whose mothers had no risk factors like infections and early membrane ruptures were studied.

Müzeyyen Mamal Torun; Hrisi Bahar; Emel Gür; Yücel Ta?tan; Müjgan Alika?ifo?lu; Ahmet Arvas

2002-01-01

213

Anaerobic brain abscess following chronic suppurative otitis media in a child from Uganda  

PubMed Central

Brain abscess, while rare, confers high mortality, especially in the developing world. The case of a Ugandan child with a polymicrobial brain abscess including infection with Tissierella praeacuta/Clostridium hastiforme requiring repeated drainage and eventual surgical excision is reported. The case demonstrates the importance of considering anaerobic organisms in the treatment of children with brain abscess from the developing world. PMID:20808460

Cox, KA; Al-Rawahi, G; Kollmann, TR

2009-01-01

214

Microbiology of Anaerobic Sludge Fermentation  

PubMed Central

An anaerobic medium containing sludge supernatant fluid and glucose was used for enumeration of bacteria from the sludge fermentation. Comparison of viable counts from several separate samples consistently showed 10 to 100 times more anaerobic than aerobic bacteria. However, viable counts of the various samples differed by as much as 10 times; this variation probably reflects a change in the natural environment or sampling errors, or a combination of the two. Direct microscopic counts yielded values of about 1010/ml. The discrepancy between viable (108 to 109/ml) and direct counts may be due to large numbers of dead cells. Random isolates of representative colonies from high dilutions exhibited the ability to ferment sugars and are not likely to be methane bacteria. PMID:5645419

Mah, Robert A.; Sussman, Carol

1968-01-01

215

Anaerobic Power and Muscle Strength in Human Immunodeficiency Virus-Positive Preadolescents  

PubMed Central

Objective To determine the anaerobic power and muscle strength of preadolescents with human immunodeficiency virus (HIV). Design Cross-sectional design. Setting Human performance laboratory at the University District Hospital at the Puerto Rico Medical Center. Participants Fifteen preadolescents (8 girls and 7 boys) with a classification of HIV A and B attending an investigational treatment program at the University Pediatric Hospital. Fifteen seronegative control subjects matched by age and gender also were included. Main Outcome Measures The power of the lower extremities was measured with use of the Wingate Anaerobic Power Test on a MONARK cycle ergometer (mean power in watts). Local muscle strength of the dominant knee extensors (peak torque/body weight × 100) was tested with an isokinetic dynamometer set at 60 deg/s. Statistical analysis was performed with the Wilcoxon signed-rank test, and statistical significance was accepted at an ? level of <.05. Results No significant differences between the control group and study group were detected on muscle strength testing. The study group presented a lower anaerobic power (mean power) compared with control subjects (P = .04). Conclusions This exploratory study suggests that HIV-infected preadolescents present lower anaerobic power compared with uninfected control subjects. Our findings of impaired anaerobic capacity can have clinical implications in this population because most of the activities of daily living, such as play, leisure, and sport activities, are short term and high intensity (anaerobic) in nature. PMID:22364955

Ramos, Edwardo; Guttierrez-Teissoonniere, Suzanne; Conde, Jose G.; Baez-Cordova, Jose A.; Guzman-Villar, Brenda; Lopafegui-Corsino, Edgar; Frontera, Walter R.

2013-01-01

216

TECHNOLOGY ASSESSMENT OF ANAEROBIC SYSTEMS FOR MUNICIPAL WASTEWATER TREATMENT: 1. ANAEROBIC FLUIDIZED BED. 2. ANFLOW  

EPA Science Inventory

This report discusses two developing technologies for the treatment of municipal wastewaters. These technologies are anaerobic fluidized bed systems and an anaerobic fixed-film bioreactor (ANFLOW). The report discusses: available laboratory data on system performance; fluidized b...

217

Kinetics and Modeling of Anaerobic Digestion Process  

Microsoft Academic Search

Anaerobic digestion modeling started in the early 1970s when the need for design and efficient operation of anaerobic systems\\u000a became evident. At that time not only was the knowledge about the complex process of anaerobic digestion inadequate but also\\u000a there were computational limitations. Thus, the first models were very simple and consisted of a limited number of equations.\\u000a During the

Hariklia Gavala; Irini Angelidaki; Birgitte Ahring

218

Isolation of Bacteroides ureolyticus (B corrodens) from clinical infections.  

PubMed Central

The introduction of an improved anaerobic system resulted in the isolation of Bacteroides ureolyticus (B corrodens) in numbers that suggested a pathogenic role from many more clinical specimens. During a three-year period B ureolyticus was isolated from 103 fairly superficial necrotic or gangrenous lesions all of which showed evidence of active infection. These included 27 perineal or genital infections, 15 perianal abscesses, 15 other soft tissue infections such as pilonidal abscesses and infected sebaceous cysts and 16 ulcers or gangrenous lesions of the lower limb. B ureolyticus was rarely isolated in pure culture but was usually one of the predominant organisms; the other organisms were mostly anaerobes and the combination of B ureolyticus with anaerobic Gram-positive cocci was particularly noticeable. The isolation and identification of B ureolyticus is not difficult but depends upon a reliable anaerobic system and the incubation of primary cultures for at least 72 h. PMID:7068922

Duerden, B; Bennet, K W; Faulkner, J

1982-01-01

219

Basic Laboratory Culture Methods for Anaerobic Bacteria  

NASA Astrophysics Data System (ADS)

Oxygen is either limiting or absent in many ecosystems. Anaerobic bacteria are often key players in such environments and these organisms have important roles in geo-elemental cycling, agriculture, and medicine. The metabolic versatility of anaerobes is exploited in a variety of industrial processes including fermented food production, biochemical synthesis, and bioremediation. There has been recent considerable interest in developing and enhancing technologies that employ anaerobes as biocatalysts. The study of anaerobic bacteria requires specialized techniques, and specific methods are described for the culture and manipulation of these microbes.

Strobel, Herbert J.

220

Proliferation and odontogenic differentiation of BMP2 gene-transfected stem cells from human tooth apical papilla: An in vitro study  

PubMed Central

Stem cells from the apical papilla (SCAP) have odontogenic potential, which plays a pivotal role in the root dentin development of permanent teeth. Human bone morphogenetic protein 2 (BMP2) is a well-known gene that participates in regulating the odontogenic differentiation of dental tissue-derived stem cells. However, little is known regarding the effects of the BMP2 gene on the proliferation and odontogenic differentiation of SCAP. This study aimed to evaluate the odontogenic differentiation potential of lentiviral-mediated BMP2 gene-transfected human SCAP (SCAP/BMP2) in vitro. SCAP were isolated by enzymatic dissociation of human teeth apical papillae. The multipotential of SCAP was verified by their osteogenic and adipogenic differentiation characteristics. The phenotype of SCAP was evaluated by flow cytometry (FCM). The proliferation status of the blank vector-transfected SCAP (SCAP/Vector) and SCAP/BMP2 was analyzed by a cell counting kit-8 (CCK-8). Odontogenic genes, including alkaline phosphatase (ALP), osteocalcin (OCN), dentin sialophosphoprotein (DSPP) and dentin matrix protein 1 (DMP1) of the two groups of cells were evaluated by quantitative polymerase chain reaction (qPCR). ALP staining and alizarin red (AR) staining of the cells was performed on the 16th day after transfection. In vitro results of CCK-8, qPCR, ALP and AR staining demonstrated that: i) SCAP/BMP2 had a comparable proliferation rate to SCAP/Vector; ii) SCAP/BMP2 presented significantly better potential to differentiate into odontoblasts compared to SCAP/Vector by upregulating ALP, OCN, DSPP and DMP1 genes; iii) more ALP granules and mineralized deposits were formed by SCAP/BMP2 as compared to SCAP/Vector. The results suggested that lentiviral-mediated BMP2 gene transfection enhances the odontogenic differentiation capacity of human SCAP in vitro. PMID:25070743

ZHANG, WEN; ZHANG, XIAOLEI; LING, JUNQI; LIU, WEI; ZHANG, XINCHUN; MA, JINGLEI; ZHENG, JIANMAO

2014-01-01

221

Glandular odontogenic cyst: review of literature and report of a new case with cytokeratin-19 expression.  

PubMed

The glandular odontogenic cyst (GOC) was a rare jawbone cyst described in 1988 as a distinct entity. This lesion can involve either jaw, and the anterior region of the mandible was the most commonly affected area. Clinical and radiographic findings were not specific, and the diagnosis of GOC can be extremely difficult due to the rarity of this lesion. The cyst presented a wall constituted by fibrous connective tissue and was lined by a non-keratinized stratified squamous epithelium of variable thickness. Large areas of the lining epithelium presented cylinder cells, sometimes ciliated. A variable amount of mucina was occasionally noted. Due to the strong similarities, this cyst can be easily misdiag-nosed as a central mucoepidermoid carcinoma (CMEC). Immunohistochemistry may be an aid in diagnosis; in fact has been demonstrated that there were differences in the expression of cytokeratins (CK) in GOC and CMEC. In this study, we reported a new case of GOC in a 38 year female patient. In addition, we carried out a review of 110 previous cases reported in literature. PMID:24624237

Mascitti, Marco; Santarelli, Andrea; Sabatucci, Antonio; Procaccini, Maurizio; Lo Muzio, Lorenzo; Zizzi, Antonio; Rubini, Corrado

2014-01-01

222

Glandular Odontogenic Cyst: Review of Literature and Report of a New Case with Cytokeratin-19 Expression  

PubMed Central

The glandular odontogenic cyst (GOC) was a rare jawbone cyst described in 1988 as a distinct entity. This lesion can involve either jaw, and the anterior region of the mandible was the most commonly affected area. Clinical and radiographic findings were not specific, and the diagnosis of GOC can be extremely difficult due to the rarity of this lesion. The cyst presented a wall constituted by fibrous connective tissue and was lined by a non-keratinized stratified squamous epithelium of variable thickness. Large areas of the lining epithelium presented cylinder cells, sometimes ciliated. A variable amount of mucina was occasionally noted. Due to the strong similarities, this cyst can be easily misdiag-nosed as a central mucoepidermoid carcinoma (CMEC). Immunohistochemistry may be an aid in diagnosis; in fact has been demonstrated that there were differences in the expression of cytokeratins (CK) in GOC and CMEC. In this study, we reported a new case of GOC in a 38 year female patient. In addition, we carried out a review of 110 previous cases reported in literature. PMID:24624237

Mascitti, Marco; Santarelli, Andrea; Sabatucci, Antonio; Procaccini, Maurizio; Muzio, Lorenzo Lo; Zizzi, Antonio; Rubini, Corrado

2014-01-01

223

Parietal subdural empyema as complication of acute odontogenic sinusitis: a case report  

PubMed Central

Introduction To date intracranial complication caused by tooth extractions are extremely rare. In particular parietal subdural empyema of odontogenic origin has not been described. A literature review is presented here to emphasize the extreme rarity of this clinical entity. Case presentation An 18-year-old Caucasian man with a history of dental extraction developed dysarthria, lethargy, purulent rhinorrhea, and fever. A computed tomography scan demonstrated extensive sinusitis involving maxillary sinus, anterior ethmoid and frontal sinus on the left side and a subdural fluid collection in the temporal-parietal site on the same side. He underwent vancomycin, metronidazole and meropenem therapy, and subsequently left maxillary antrostomy, and frontal and maxillary sinuses toilette by an open approach. The last clinical control done after 3 months showed a regression of all symptoms. Conclusions The occurrence of subdural empyema is an uncommon but possible sequela of a complicated tooth extraction. A multidisciplinary approach involving otolaryngologist, neurosurgeons, clinical microbiologist, and neuroradiologist is essential. Antibiotic therapy with surgical approach is the gold standard treatment. PMID:25146384

2014-01-01

224

A Keratocyst in the Buccal Mucosa with the Features of Keratocystic Odontogenic Tumor  

PubMed Central

A 74-year-old male patient consulted us for an elastic firm mass in the right buccal mucosa. CT examination revealed a well-circumscribed oval cystic lesion in the anterior region of the masseter muscle. On MRI, the lesion showed a low signal on T1-weighted image and a high signal on T2-weighted image. Aspiration biopsy demonstrated the presence of squamous cells in whitish liquid. Under the diagnosis of epidermoid cyst, the lesion was intraorally extirpated under general anesthesia. The lesion was cystic at the size of 30 × 25mm. Histologically, the cyst wall was lined with parakeratinized squamous epithelium corrugated on its surface, the basal layer of which consisted of cuboidal cells showing palisading of the nuclei. Immunohistochemically, the lining epithelium was positive for CK17 and negative for CK10. The basal and suprabasal cells were labeled for Ki-67 at a relatively high rate. These features are compatible with those of keratocystic odontogenic tumor. PMID:24285986

Yamamoto, Kazuhiko; Matsusue, Yumiko; Kurihara, Miyako; Takahashi, Yuka; Kirita, Tadaaki

2013-01-01

225

Correlation between imaging features and epithelial cell proliferation in keratocystic odontogenic tumour  

PubMed Central

Objectives This study was undertaken to investigate the relationship between radiographic appearance and epithelial cell proliferations in keratocystic odontogenic tumours (KCOTs). Methods A retrospective radiographic analysis was performed on 284 cases of KCOT to gain insight into the radiographic characteristics. Expression of Ki-67 in 30 of the 284 cases was detected by the labelled streptavidin–biotin (LSAB) method and evaluated by an image analysis system. Results The radiographic presentation of KCOT was divided into four types: unilocular, multilocular, multiple and naevoid basal cell carcinoma syndrome (NBCCS). The expression of Ki-67 in NBCCS was significantly different from the solitary and multiple KCOTs (P = 0.018, 0.002). In multilocular KCOTs it was also significantly different from the unilocular and syndrome-associated lesions (P = 0.000). In contrast, no significant differences were observed between the solitary and multiple lesions (P = 0.220). Conclusions A high correlation exists in KCOT between its biological behaviour and imaging features. The solitary KCOT seems less biologically aggressive and it should be classified as a cyst rather than a tumour. This means that more than half of KCOTs manifest themselves as ordinary cysts. PMID:20729187

K; Li, X; Wang, H; Liu, Y; Zheng, G; Yang, Z; Li, M; Shimizutani, K; Koseki, T

2010-01-01

226

Odontogenic keratocysts: a clinical and histologic comparison of the parakeratin and orthokeratin variants.  

PubMed

Four hundred forty-nine cases of odontogenic keratocyst (OKC) were separated into three histologic categories: parakeratinized, orthokeratinized, or a combination of the two types. Demographic and clinical data, such as anatomic location and recurrence, were obtained from the biopsy forms. Results showed that 86.2% of the 449 cases were parakeratinized, 12.2% were orthokeratinized, and 1.6% had features of both orthokeratin and parakeratin. There were no statistically significant differences between orthokeratinized and parakeratinized OKCs when age, race, sex, presenting symptoms, and the clinical impression were compared. The orthokeratinized OKC was more often associated with an impacted tooth (75.7%), as compared with 47.8% for the parakeratinized OKC (P = .001). Parakeratinized OKCs recurred in at least 42.6% of the cases, compared with only 2.2% for orthokeratinized OKCs. This study emphasizes the importance of distinguishing between the parakeratin and orthokeratin variants of OKC. In addition, data are presented that show the need for longer follow-up than previously documented. PMID:1370082

Crowley, T E; Kaugars, G E; Gunsolley, J C

1992-01-01

227

Glandular odontogenic cyst mimicking ameloblastoma in a 78-year-old female: A case report  

PubMed Central

Glandular odontogenic cyst (GOC) is a rare, potentially aggressive jaw lesion. The common radiographic features include a well-defined radiolucency with distinct borders, presenting a uni- or multilocular appearance. A cystic lesion in the posterior mandible of a 78-year-old female was incidentally found. Radiographs showed a unilocular lesion with a scalloped margin, external root resorption of the adjacent tooth, and cortical perforation. This lesion had changed from a small ovoid shape to a more expanded lesion in a period of four years. The small lesion showed unilocularity with a smooth margin and a well-defined border, but the expanded lesion produced cortical perforation and a lobulated margin. The provisional diagnosis was an ameloblastoma, whereas the histopathological examination revealed a GOC. This was a quite rare case, given that this radiographic change was observed in the posterior mandible of an elderly female. This case showed that a GOC can grow even in people in their seventies, changing from the unilocular form to an expanded, lobulated lesion. Here, we report a case of GOC with characteristic radiographic features.

Lee, Wan; Kwon, Kyung-Hwan; Choi, Moon-Ki; Choi, Eun-Joo; Yoon, Jung-Hoon

2014-01-01

228

Fourth Belgian multicentre survey of antibiotic susceptibility of anaerobic bacteria  

PubMed Central

Objectives To collect recent data on the susceptibility of anaerobes to antimicrobial agents with known activity against anaerobes, and to compare them with results from previous Belgian multicentre studies. Methods Four hundred and three strict anaerobic clinical isolates were prospectively collected from February 2011 to April 2012 in eight Belgian university hospitals. MICs were determined by one central laboratory for 11 antimicrobial agents using Etest methodology. Results According to EUCAST breakpoints, >90% of isolates were susceptible to amoxicillin/clavulanate (94%), piperacillin/tazobactam (91%), meropenem (96%), metronidazole (92%) and chloramphenicol (98%), but only 70% and 40% to clindamycin and penicillin, respectively. At CLSI recommended breakpoints, only 71% were susceptible to moxifloxacin and 79% to cefoxitin. MIC50/MIC90 values for linezolid and for tigecycline were 1/4 and 0.5/4 mg/L, respectively. When compared with survey data from 2004, no major differences in susceptibility profiles were noticed. However, the susceptibility of Prevotella spp. and other Gram-negative bacilli to clindamycin decreased from 91% in 1993–94 and 82% in 2004 to 69% in this survey. Furthermore, the susceptibility of clostridia to moxifloxacin decreased from 88% in 2004 to 66% in 2011–12 and that of fusobacteria from 90% to 71%. Conclusions Compared with previous surveys, little evolution was seen in susceptibility, except a decline in activity of clindamycin against Prevotella spp. and other Gram-negative bacteria, and of moxifloxacin against clostridia. Since resistance was detected to all antibiotics, susceptibility testing of anaerobic isolates is indicated in severe infections to confirm appropriateness of antimicrobial therapy. PMID:24008826

Wybo, Ingrid; Van den Bossche, Dorien; Soetens, Oriane; Vekens, Evilien; Vandoorslaer, Kristof; Claeys, Geert; Glupczynski, Youri; Ieven, Margareta; Melin, Pierrette; Nonhoff, Claire; Rodriguez-Villalobos, Hector; Verhaegen, Jan; Pierard, Denis

2014-01-01

229

In Vitro Activity of Ceftaroline against 623 Diverse Strains of Anaerobic Bacteria ?  

PubMed Central

The in vitro activities of ceftaroline, a novel, parenteral, broad-spectrum cephalosporin, and four comparator antimicrobials were determined against anaerobic bacteria. Against Gram-positive strains, the activity of ceftaroline was similar to that of amoxicillin-clavulanate and four to eight times greater than that of ceftriaxone. Against Gram-negative organisms, ceftaroline showed good activity against ?-lactamase-negative strains but not against the members of the Bacteroides fragilis group. Ceftaroline showed potent activity against a broad spectrum of anaerobes encountered in respiratory, skin, and soft tissue infections. PMID:20100877

Citron, D. M.; Tyrrell, K. L.; Merriam, C. V.; Goldstein, E. J. C.

2010-01-01

230

Anaerobic bacteria from hypersaline environments.  

PubMed Central

Strictly anaerobic halophiles, namely fermentative, sulfate-reducing, homoacetogenic, phototrophic, and methanogenic bacteria are involved in the oxidation of organic carbon in hypersaline environments. To date, six anaerobic fermentative genera, containing nine species, have been described. Two of them are homoacetogens. Six species belong to the family Haloanaerobiaceae, as indicated by their unique 16S rRNA oligonucleotide sequences. Desulfohalobium retbaense and Desulfovibrio halophilus represent the only two moderately halophilic sulfate reducers so far reported. Among anoxygenic phototrophic anaerobes, a few purple bacteria with optimal growth at salinities between 6 and 11% NaCl have been isolated from hypersaline habitats. They belong to the genera Rhodospirillum, Chromatium, Thiocapsa, and Ectothiorhodospira. The commonest organisms isolated so far are Chromatium salexigens, Thiocapsa halophila, and Rhodospirillum salinarum. Extremely halophilic purple bacteria have most commonly been isolated from alkaline brines and require about 20 to 25% NaCl for optimal growth. They belong to the family Ectothiorodhospiraceae. Their osmoregulation involves synthesis or uptake of compatible solutes such as glycine-betaine that accumulate in their cytoplasm. The existence of methanogens in hypersaline environments is related to the presence of noncompetitive substrates such as methylamines, which originate mainly from the breakdown of osmoregulatory amines. Methanogenesis probably does not contribute to the mineralization of carbohydrates at NaCl concentrations higher than 15%. Above this concentration, sulfate reduction is probably the main way to oxidize H2 (although at rates too low to use up all the H2 formed) and occupies a terminal function kn the degradation of carbohydrates. Three genera and five species of halophilic methylotrophic methanogens have been reported. A bloom of phototrophic bacteria in the marine salterns of Salins-de-Giraud, located on the Mediterranean French coast in the Rhone Delta, is also described. PMID:8177169

Ollivier, B; Caumette, P; Garcia, J L; Mah, R A

1994-01-01

231

Epigenetic marks define the lineage and differentiation potential of two distinct neural crest-derived intermediate odontogenic progenitor populations.  

PubMed

Epigenetic mechanisms, such as histone modifications, play an active role in the differentiation and lineage commitment of mesenchymal stem cells. In the present study, epigenetic states and differentiation profiles of two odontogenic neural crest-derived intermediate progenitor populations were compared: dental pulp (DP) and dental follicle (DF). ChIP on chip assays revealed substantial H3K27me3-mediated repression of odontoblast lineage genes DSPP and dentin matrix protein 1 (DMP1) in DF cells, but not in DP cells. Mineralization inductive conditions caused steep increases of mineralization and patterning gene expression levels in DP cells when compared to DF cells. In contrast, mineralization induction resulted in a highly dynamic histone modification response in DF cells, while there was only a subdued effect in DP cells. Both DF and DP progenitors featured H3K4me3-active marks on the promoters of early mineralization genes RUNX2, MSX2, and DLX5, while OSX, IBSP, and BGLAP promoters were enriched for H3K9me3 or H3K27me3. Compared to DF cells, DP cells expressed higher levels of three pluripotency-associated genes, OCT4, NANOG, and SOX2. Finally, gene ontology comparison of bivalent marks unique for DP and DF cells highlighted cell-cell attachment genes in DP cells and neurogenesis genes in DF cells. In conclusion, the present study indicates that the DF intermediate odontogenic neural crest lineage is distinguished from its DP counterpart by epigenetic repression of DSPP and DMP1 genes and through dynamic histone enrichment responses to mineralization induction. Findings presented here highlight the crucial role of epigenetic regulatory mechanisms in the terminal differentiation of odontogenic neural crest lineages. PMID:23379639

Gopinathan, Gokul; Kolokythas, Antonia; Luan, Xianghong; Diekwisch, Thomas G H

2013-06-15

232

40 CFR Table II-2 to Subpart II - Collection Efficiencies of Anaerobic Processes  

Code of Federal Regulations, 2013 CFR

...Efficiencies of Anaerobic Processes Anaerobic process type Cover type Methane collection efficiency Covered anaerobic lagoon (biogas capture) Bank to bank, impermeable 0.975 Modular, impermeable 0.70 Anaerobic sludge digester; anaerobic...

2013-07-01

233

Incidental discovery of odontogenic keratocyst in an edentulous patient: importance of routine pre-prosthetic radiographic evaluation.  

PubMed

The most common modality of treatment for completely edentulous patients are conventional removable complete dentures. The protocol for fabrication of complete denture would involve a thorough clinical examination and radiographic investigation. As a routine, unless clinical findings suggest presence of remnant tooth structures, or the patient presents himself with symptoms, the radiographic investigations are overlooked. This case report presents one such situation wherein routine radiographic evaluation of a clinically asymptomatic edentulous individual prior to prosthetic rehabilitation revealed the presence of an odontogenic keratocyst of anterior maxilla substantiating the importance of such routine pre-prosthetic radiographic investigations. PMID:22942581

Thamizhchelvan, H; Malathi, N; Radhika, T; Padmanabhan, T V; Nandakumar, N; Santhosh Kumar, K

2011-09-01

234

Anaerobic Digestion of Agricultural Solid Residues  

Microsoft Academic Search

Agricultural residues can be converted to methane-rich gas mixture. Anaerobic biomethane production is an effective process for conversion of a broad variety of agricultural residues to methane to substitute natural gas and medium calorific value gases. Methane generating bacteria (methanogens) and other microbes that help digest dying plants in anaerobic conditions. Agricultural solid residues (ASR) represent a potential energy resource

Ayhan Demirbas; Temel Ozturk

2005-01-01

235

Factor Analysis of Various Anaerobic Power Tests.  

ERIC Educational Resources Information Center

A study investigated the relationship between selected anthropometric variables and of numerous anaerobic power tests with measures obtained on an isokinetic dynamometer. Thirty-one male college students performed several anaerobic power tests, including: the vertical jump using the Lewis formula; the Margaria-Kalamen stair climb test; the Wingate…

Manning, James M.; And Others

236

Anaerobic Membrane Bioreactors: Applications and Research Directions  

Microsoft Academic Search

Membranes provide exceptional suspended solids removal and complete biomass retention that can improve the biological treatment process, but their commercial application to anaerobic treatment has been limited. This review summarizes the state of the art with respect to anaerobic membrane bioreactors (AnMBRs), determines the types of wastewaters for which AnMBRs would be best suited, and identifies the research required to

Bao-Qiang Liao; Jeremy T. Kraemer; David M. Bagley

2006-01-01

237

Anaerobic pretréatment of concentrated pharmaceutical wastes  

Microsoft Academic Search

The purpose of this study was to investigate the anaerobic ammonification of wastewater from an estrogen extracting pharmaceutical plant. The wastewater was very high in total dissolved solids (TDS), nitrogen (TKN) and organic carbon (TOC). Both flow?through and batch anaerobic reactors were used. TDS concentrations over 17 g L in the flow?through reactors and in excess of 10 g L

S. Shafai; Jan A. Oleszkiewicz

1987-01-01

238

[The surgical procedure in acute anaerobic paraproctitis].  

PubMed

A method of active outstripping incisions with special reference to the localization of the primary anaerobic focus and possible pathways of the spreading of purulent exudate is proposed on the basis of experiences with surgical treatment of 14 patients with acute anaerobic paraproctitis and investigations of topographical-anatomical localization of cellular spaces in the pararectal area. PMID:8091577

Toropov, Iu D; Stavitski?, V V; ZgurskiI, V G; Kravtsov, N G

1993-01-01

239

Methanosaeta fibers in anaerobic migrating blanket reactors  

E-print Network

Methanosaeta fibers in anaerobic migrating blanket reactors L.T. Angenent,* D. Zheng,* S. Sung An anaerobic migrating blanket reactor (AMBR) was seeded with flocculent biomass from a digester and fed of operation, a mature granular blanket developed in the reactor. Moreover, fibers of approximately 1 cm long

Angenent, Lars T.

240

Anaerobic bioprocessing of low-rank coals  

SciTech Connect

The objective of this project is to find biological methods to remove carboxylic functionalities from low rank coals under ambient conditions and to assess the properties of these modified coals towards coal decarboxylation. The microbial consortia will be developed using a fermentor system first under batch and then in a continuous system. The main objectives for this quarter were to develop microbial consortia that would decarboxylate coal and isolate potential anaerobic microorganisms with decarboxylating, ability from these enriched microbial consortia, to continue to compare the known cultures with reward to their ability to decarboxylate coal, and to characterize the anaerobically biotreated coal using FTIR to confirm decarboxylation of coal. Significant achievements during the period include: coal decarboxylation was possible only under anaerobic conditions. microbial consortia that can anaerobically decarboxylate coal have been developed using anaerobic vials and batch fermentor system, and loss of carboxyl groups in biotreated coal has been confirmed by FT-IR.

Jain, M.K.; Narayan, R.; Han, O.

1991-01-01

241

Anaerobic acidogenesis of dairy manure  

SciTech Connect

The objective of this research was to determine if high rate acidogenic fermentation of dairy manure was possible, Whole dairy manure was ground and diluted to 4% total solids and fed to a 10 L anaerobic chemostat operating at 35C and with hydraulic retention times varying between 6 and 50 hours. Several physical and organic parameters of the influent and effluent were measured and compared. The results indicated that the manure was too refractory for high rate liquefaction and hydrolysis. A second experiment was conducted using the same techniques and substrate but varying the substrate pH between 5 and 7. The objectives were to further investigate the pH sensitivity of the acidogenic process and to determine if, by introducing a substrate with a low pH, acidogenesis might proceed more efficiently. The primary result of decreasing the pH was a smaller proportion of methane and an increased proportion of hydrogen in the gas. Liquefaction and hydrolysis continued to be rate limiting and appeared to be a major impediment to two phase anaerobic treatment of dairy manure.

Krones, M.J.

1989-01-01

242

Anaerobic digestion in rural China  

SciTech Connect

The People`s Republic of China has been promoting underground, individual, anaerobic digesters to process rural organic materials. This strategy has resulted in approximately five million household anaerobic digesters installed in China today. Simple reactors provide energy and fertilizer for Chinese farms and villages. Another benefit includes improved household sanitation. Reactor design has evolved over time. In the standard modern design, effluent is removed from the reactor at the top of the water column, meaning that supernatant is collected rather than sludge. Additionally, no mixing of the system occurs when effluent is removed. In some systems, a vertical cylindrical pull-rod port is added to the base of the effluent port. Effluent is removed by moving the pull-rod - simply a wooden shaft with a metal disk on the bottom - up and down in the port. A bucket can be placed directly under the pull-rod port, simplifying effluent removal, while the movement of the wooden shaft provides some mixing in the reactor. The gas primarily is used for cooking and lighting. A digester can provide approximately 60 percent of a family`s energy needs. Effluent from the reactors is an odorless, dark colored slurry, primarily used as an agricultural fertilizer. 3 figs.

Henderson, J.P. [City of Vancouver (Canada)

1997-01-01

243

Anaerobic digestion for household organics  

SciTech Connect

Considerable success in using anaerobic technology for processing household organics is being reported by several recently constructed facilities in Europe. Organic residuals collected separately in a Belgian town are processed to produce biogas and a compost-like material in less than one month. The dry anaerobic conversion process (DRANCO) was developed by Organic Waste Systems (OWS) in the 1980s, with the collaboration of Professor Willy Verstraete at the University of Ghent`s Laboratory of Applied Microbial Ecology. The patented process converts solid and semisolid organic residuals into biogas (for energy recovery) and a stable humus like product. The plant has competing odor sources such as the active landfill and the surrounding farmland - in fact, the smell of livestock manure is quite prevalent in this heavily agricultural area. Addition of the nonrecyclable paper fraction to the feedstock improves the carbon/nitrogen ratio, soaks up moisture, and absorbs odor. The entire Brecht facility does not occupy much space and total material retention time at the site is one month, compared to a number of months for aerobic systems. It also has a low staffing requirement, provides energy self-sufficiency, and the final soil enhancement product meets established quality standards.

Sinclair, R.; Kelleher, M.

1995-04-01

244

Differential Susceptibility of Bacteria to Mouse Paneth Cell ?-Defensins under Anaerobic Conditions  

PubMed Central

Small intestinal Paneth cells secrete ?-defensin peptides, termed cryptdins (Crps) in mice, into the intestinal lumen, where they confer immunity to oral infections and define the composition of the ileal microbiota. In these studies, facultative bacteria maintained under aerobic or anaerobic conditions displayed differential sensitivities to mouse ?-defensins under in vitro assay conditions. Regardless of oxygenation, Crps 2 and 3 had robust and similar bactericidal activities against S. Typhimurium and S. flexneri, but Crp4 activity against S. flexneri was attenuated in the absence of oxygen. Anaerobic bacteria varied in their susceptibility to Crps 2–4, with Crp4 showing less activity than Crps 2 and 3 against Enterococcus faecalis, and Bacteroides fragilis in anaerobic assays, but Fusobacterium necrophorum was killed only by Crp4 and not by Crps 2 and 3. The influence of anaerobiosis in modulating Crp bactericidal activities in vitro suggests that ?-defensin effects on the enteric microbiota may be subject to regulation by local oxygen tension. PMID:25383215

Mastroianni, Jennifer R.; Lu, Wuyuan; Selsted, Michael E.; Ouellette, Andre J.

2014-01-01

245

[Structure of maxillary sinus mucous membrane under normal conditions and in odontogenic perforative sinusitis].  

PubMed

Methods of light, electron microscopy and immunohistochemistry were used to study the samples of maxillary sinus (MS) mucous membrane (MM) under normal conditions and in odontogenic sinusitis. To study the normal structure, the samples were obtained at autopsy from 26 human corpses 12-24 hours after death. Electron microscopic and immunohistochemical study was performed on biopsies of grossly morphologically unchanged MS MM, obtained during the operations for retention cysts in 6 patients. MS MM in perforative sinusitis was studied using the biopsies obtained from 43 patients. The material is broken into 4 groups depending on perforative sinusitis duration. Under normal conditions, MS MM is lined with a pseudostratified columnar ciliated epithelium. Degenerative changes of ciliated epithelial cells were already detected at short time intervals after MS perforations and become apparent due to reduction of specific volume of mitochondria and, rough endoplasmic reticulum, and increase of nuclear-cytoplasmic ratio. In the globlet cells, the reduction of nuclear-cytoplasmic ratio was associated with the disturbance of the secretory product release. At time intervals exceeding 3 months, epithelium underwent metaplasia into simple cuboidal and stratified squamous keratinized, while in MS MM lamina propria, cellular infiltration was increased. CD4+ cell content in sinus MM gradually increased, while at late periods after perforation occurrence it decreased. Low CD4+ cell count within the epithelium and the absence of muromidase on the surface of MS MM was detected. With the increase of the time interval since MS perforation, the number of CD8+ and CD20+ cells in MS MM was found to increase. PMID:21866807

Ba?dik, O D; Logvinov, S V; Zubarev, S G; Sysoliatin, P G; Gurin, A A

2011-01-01

246

Establishment and characterization of a primary calcifying epithelial odontogenic tumor cell population  

PubMed Central

Calcifying epithelial odontogenic tumors (CEOTs) are rare neoplasms derived from dental tissue with the unique characteristic of calcifying amyloid-like material. Objectives To establish primary CEOT epithelial-derived cell populations, investigate the expression of enamel matrix proteins (EMPs), and identify potential ameloblastin (AMBN) and patched I (PTCHI) gene alterations. Materials and Methods A 28-year-old patient with a lesion of the posterior maxilla, radiographically characterized by a radiolucency with well-defined borders containing mixed radiopacities, agreed to participate with informed consent. The patient's biopsy confirmed the diagnosis of CEOT, and a small representative tumor fragment was ascertained for cell culture. Explant cultures were established and used to establish primary cell populations. These were analyzed for morphology, cell proliferation, mineralization activity, expression of epithelial-associated markers (qRT-PCR and immunocytochemistry), and gene mutations of AMBN or PTCHI. DNA was extracted from tumor cells and gene coding and exon–intron boundaries overlapping fragments amplified. PCR products were bidirectional DNA sequenced and compared against reference sequence. Results A CEOT cell population was established and proliferated in culture and could be maintained for several passages. Expression of EMPs, cytokeratin 14 and 17, and patched (PTCHI), as well as ALP activity, was detected. These cells also had the ability to mineralize, similar to the primary tumor. Two AMBN alterations were identified in the sample: c.1323G>A/A441A (rs7680880) and c.1344*+111delA. Two single-nucleotide polymorphisms were identified in the PTCHI gene. Conclusions Our data support the establishment of a CEOT-derived cell population, which expresses known epithelial-associated proteins. PMID:24118390

Amm, Hope M.; Rollins, Douglas L.; Ren, Changchun; Dong, Juan; DeVilliers, Patricia; Rivera, Helen; MacDougall, Mary

2014-01-01

247

Orthokeratinized odontogenic cyst in a Hong Kong community: the clinical and radiological features  

PubMed Central

Objectives The aim was to evaluate the principal clinical and conventional radiological features of a consecutive series of cases of orthokeratinized odontogenic cyst (OOC) affecting a Hong Kong Chinese community and to determine the outcome by follow-up. Methods All cases were accompanied by appropriate radiography and were confirmed by histopathology. Results The clinical and conventional radiological presentations, differential diagnoses and outcomes of follow-up of five consecutive OOCs were reviewed. There were two males and three females. All affected the posterior sextant. The mean age at first presentation was 33.5 years. The mean of their period of prior awareness was 0.11 years. Swelling was the most frequent presenting symptom. All presented as well-defined corticated radiolucencies; three were unilocular and two were multilocular and all displayed expansion. This resulted in displacement and erosion of the lower border of the mandible in one case and the downward displacement past the lower border of a lateral cortex in two others. The inferior dental canal in each mandibular case exhibited both displacement and absence. The antrum was affected in a sole maxillary case. Four patients were followed up for a mean of 8.5 years. The fifth patient discharged himself shortly after surgery. No lesions recurred. Conclusions OOCs in this community displayed an expansile character, but did not recur after moderately long follow-up. The time between the prior awareness of their disease and their presentation for diagnosis and treatment was, so far, the shortest for any lesion affecting the jaw in this Hong Kong Chinese community. PMID:20395466

MacDonald-Jankowski, D S; Li, T K

2010-01-01

248

Comparative analysis of in vitro osteo\\/odontogenic differentiation potential of human dental pulp stem cells (DPSCs) and stem cells from the apical papilla (SCAP)  

Microsoft Academic Search

ObjectiveThe aim of this study was to compare the in vitro osteo\\/odontogenic differentiation potential of mesenchymal stem cells (MSCs) derived from the dental pulp (dental pulp stem cells – DPSCs) or the apical papilla (stem cells from the apical papilla – SCAP) of permanent developing teeth.

A. Bakopoulou; G. Leyhausen; J. Volk; A. Tsiftsoglou; P. Garefis; P. Koidis; W. Geurtsen

2011-01-01

249

Clinicopathological evaluation of 164 dental follicles and dentigerous cysts with emphasis on the presence of odontogenic epithelium in the connective tissue. The hypothesis of "focal ameloblastoma"  

PubMed Central

Objectives: Some ameloblastomas presumably originate from odontogenic epithelium within the connective tissue of dental follicles and dentigerous cysts. Therefore, it would seem reasonable to discuss as whether odontogenic epithelium proliferations, frankly displaying ameloblastomatous features (“focal ameloblastoma”), should be considered as an “early” ameloblastoma. Study Design: Histopathological reports from 164 dental follicles and dentigerous cysts from the Department of Oral and Maxillofacial Surgery/Oral Pathology of the VU Free University medical center in Amsterdam, The Ne-therlands, were reviewed. Histopathological slides from 39 cases reporting the presence of odontogenic epithelium within the connective tissue were re-evaluated in order to assess the possible presence of focal ameloblastomas. Results: Focal ameloblastomas were detected in one dental follicle and in two dentigerous cysts. During a follow-up period of 6, 8 and 22 years, respectively, no clinical signs of (recurrent) ameloblastoma have occurred in these patients. Conclusions: Focal ameloblastoma possibly represents the early stage of ameloblastoma development. Key words:Ameloblastoma, odontogenic epithelium, dentigerous cyst, dental follicle. PMID:23085710

Meleti, Marco

2013-01-01

250

Odontogenic differentiation of human dental pulp cells by calcium silicate materials stimulating via FGFR/ERK signaling pathway.  

PubMed

Bone healing needs a complex interaction of growth factors that establishes an environment for efficient bone formation. We examine how calcium silicate (CS) and tricalcium phosphate (?-TCP) cements influence the behavior of human dental pulp cells (hDPCs) through fibroblast growth factor receptor (FGFR) and active MAPK pathways, in particular ERK. The hDPCs are cultured with ?-TCP and CS, after which the cells' viability and odontogenic differentiation markers are determined by using PrestoBlue® assay and western blot, respectively. The effect of small interfering RNA (siRNA) transfection targeting FGFR was also evaluated. The results showed that CS promoted cell proliferation and enhances FGFR expression. It was also found that CS increases ERK and p38 activity in hDPCs, and furthermore, raises the expression and secretion of DSP, and DMP-1. Additionally, statistically significant differences (p<0.05) have been found in the calcium deposition in si-FGFR transfection and ERK inhibitor between CS and ?-TCP; these variations indicated that ERK/MAPK signaling is involved in the silicon-induced odontogenic differentiation of hDPCs. The current study shows that CS substrates play a key role in odontoblastic differentiation of hDPCs through FGFR and modulate ERK/MAPK activation. PMID:25175224

Liu, Chao-Hsin; Hung, Chi-Jr; Huang, Tsui-Hsien; Lin, Chi-Chang; Kao, Chia-Tze; Shie, Ming-You

2014-10-01

251

Identification of the involvement of LOXL4 in generation of keratocystic odontogenic tumors by RNA-Seq analysis  

PubMed Central

Keratocystic odontogenic tumors (KCOT) are benign, locally aggressive intraosseous tumors of odontogenic origin. KCOT have a higher stromal microvessel density (MVD) than dentigerous cysts (DC) and normal oral mucosa. To identify genes in the stroma of KCOT involved in tumor development and progression, RNA sequencing (RNA-Seq) was performed using samples from KCOT and primary stromal fibroblasts isolated from gingival tissues. Seven candidate genes that possess a function potentially related to KCOT progression were selected and their expression levels were confirmed by quantitative PCR, immunohistochemistry and enzyme-linked immunosorbent assay. Expression of lysyl oxidase-like 4 (LOXL4), the only candidate gene that encodes a secreted protein, was enhanced at both the mRNA and protein levels in KCOT stromal tissues and primary KCOT stromal fibroblasts compared to control tissues and primary fibroblasts (P<0.05). In vitro, high expression of LOXL4 could enhance proliferation and migration of the human umbilical vein endothelial cells (HUVECs). There was a significant, positive correlation between LOXL4 protein expression and MVD in stroma of KCOT and control tissues (r=0.882). These data suggest that abnormal expression of LOXL4 of KCOT may enhance angiogenesis in KCOT, which may help to promote the locally aggressive biological behavior of KCOT. PMID:24357854

Jiang, Wei-Peng; Sima, Zi-Han; Wang, Hai-Cheng; Zhang, Jian-Yun; Sun, Li-Sha; Chen, Feng; Li, Tie-Jun

2014-01-01

252

The role of lysyl oxidase-like 2 in the odontogenic differentiation of human dental pulp stem cells.  

PubMed

Adult human dental pulp stem cells (hDPSCs) are a unique population of precursor cells those are isolated from postnatal dental pulp and have the ability to differentiate into a variety of cell types utilized for the formation of a reparative dentin-like complex. Using LC-MS/MS proteomics approaches, we identified the proteins secreted from the differentiating hDPSCs in mineralization media. Lysyl oxidase-like 2 (LOXL2) was identified as a protein that was down-regulated in the hDPSCs that differentiate into odontoblast-like cells. The role of LOXL2 has not been studied in dental pulp stem cells. LOXL2 mRNA levels were reduced in differentiating hDPSCs, whereas the levels of other LOX family members including LOX, LOXL1, LOXL3, and LOXL4, are increased. The protein expression and secretion levels of LOXL2 were also decreased during odontogenic differentiation. Recombinant LOXL2 protein treatment to hDPSCs resulted in a dose-dependent decrease in the early differentiation and the mineralization accompanying with the lower levels of odontogenic markers such as DSPP, DMP-1 and ALP. These results suggest that LOXL2 has a negative effect on the differentiation of hDPSCs and blocking LOXL2 can promote the hDPSC differentiation to odontoblasts. PMID:23677379

Kim, Joo-Hyun; Lee, Eun-Hyang; Park, Hye-Jeong; Park, Eui-Kyun; Kwon, Tae-Geon; Shin, Hong-In; Cho, Je-Yoel

2013-06-01

253

The Role of Lysyl Oxidase-like 2 in the Odontogenic Differentiation of Human Dental Pulp Stem Cells  

PubMed Central

Adult human dental pulp stem cells (hDPSCs) are a unique population of precursor cells those are isolated from postnatal dental pulp and have the ability to differentiate into a variety of cell types utilized for the formation of a reparative dentin-like complex. Using LC-MS/MS proteomics approaches, we identified the proteins secreted from the differentiating hDPSCs in mineralization media. Lysyl oxidase-like 2 (LOXL2) was identified as a protein that was down-regulated in the hDPSCs that differentiate into odontoblast-like cells. The role of LOXL2 has not been studied in dental pulp stem cells. LOXL2 mRNA levels were reduced in differentiating hDPSCs, whereas the levels of other LOX family members including LOX, LOXL1, LOXL3, and LOXL4, are increased. The protein expression and secretion levels of LOXL2 were also decreased during odontogenic differentiation. Recombinant LOXL2 protein treatment to hDPSCs resulted in a dose-dependent decrease in the early differentiation and the mineralization accompanying with the lower levels of odontogenic markers such as DSPP, DMP-1 and ALP. These results suggest that LOXL2 has a negative effect on the differentiation of hDPSCs and blocking LOXL2 can promote the hDPSC differentiation to odontoblasts. PMID:23677379

Kim, Joo-Hyun; Lee, Eun-Hyang; Park, Hye-jeong; Park, Eui-Kyun; Kwon, Tae-Geon; Shin, Hong-In; Cho, Je-Yoel

2013-01-01

254

Effect of music on anaerobic exercise performance.  

PubMed

For years, mostly the effects of music on cardiorespiratory exercise performance have been studied, but a few studies have examined the effect of music on anaerobic exercise. The purpose of this study was to assess the effect of listening to music and its rhythm on anaerobic exercise: on power output, heart rate and the concentration of blood lactate. 28 male subjects were required to visit the laboratory on 6 occasions, each separated by 48 hours. Firstly, each subject performed the Running-based Anaerobic Sprint Test (RAST) under 3 conditions on separate days: while listening to "slow rhythm music", "fast rhythm music" or "no music". 48 hours after the subjects completed RAST under 3 conditions, Wingate Anaerobic Power (WAN) tests were performed under 3 music conditions. The order of the 3 conditions (slow music, fast music and no music) was selected randomly to prevent an order effect. Results showed no significant differences between 3 conditions in anaerobic power assessments, heart rate or blood lactate (p > 0.05). On the basis of these results it can be said that music cannot improve anaerobic performance. The type of music had no impact on power outputs during RAST and WAN exercise. As a conclusion, listening to music and its rhythm cannot enhance anaerobic performance and cannot change the physiological response to supramaximal exercise. PMID:24744463

Atan, T

2013-03-01

255

Vitamin B12-Mediated Restoration of Defective Anaerobic Growth Leads to Reduced Biofilm Formation in Pseudomonas aeruginosa  

PubMed Central

Pseudomonas aeruginosa undergoes cell elongation and forms robust biofilms during anaerobic respiratory growth using nitrate (NO3?) as an alternative electron acceptor. Understanding the mechanism of cell shape change induced upon anaerobiosis is crucial to the development of effective treatments against P. aeruginosa biofilm infection. Here, we uncovered the molecular basis of anaerobiosis-triggered cell elongation and identified vitamin B12 to be a molecule that can reinstate defective anaerobic growth of P. aeruginosa. The ratio of total cellular DNA content to protein content was significantly decreased in the PAO1 strain grown under anaerobic conditions, indicating that DNA replication is impaired during anaerobic growth. Anaerobic growth of PAO1 reached a higher cell density in the presence of vitamin B12, an essential coenzyme of class II ribonucleotide reductase. In addition, cell morphology returned to a normal rod shape and transcription of stress-response genes was downregulated under the same anaerobic growth conditions. These results suggest that vitamin B12, the production of which was suppressed during anaerobic growth, can restore cellular machineries for DNA replication and therefore facilitate better anaerobic growth of P. aeruginosa with normal cell division. Importantly, biofilm formation was substantially decreased when grown with vitamin B12, further demonstrating that anaerobiosis-induced cell elongation is responsible for robust biofilm formation. Taken together, our data reveal mechanistic details of a morphological change that naturally occurs during anaerobic growth of P. aeruginosa and illustrates the ability of vitamin B12 to modulate the biofilm-forming capacity of P. aeruginosa under such condition. PMID:22371376

Lee, Kang-Mu; Go, Junhyeok; Yoon, Mi Young; Park, Yongjin; Kim, Sang Cheol; Yong, Dong Eun

2012-01-01

256

Anaerobic Treatment of Domestic Sewage at Low Temperature  

Microsoft Academic Search

The main objective of this thesis was to asses the anaerobic treatment of domestic sewage at low temperature and the possibilities to optimize the performance of high-rate anaerobic systems treating domestic sewage at low temperature.The anaerobic biodegradability of domestic sewage and its fractions was investigated in batch experiments. The results showed a high potential of anaerobic treatment of domestic sewage

T. A. Elmitwalli; G. Zeeman; G. Lettinga

2000-01-01

257

The Role of Colour Doppler Ultrasonography in the Diagnosis of Fascial Space Infections - A Cross Sectional Study  

PubMed Central

Aims and Objectives: (1) To evaluate the role of ultrasonography with colour Doppler in the diagnosis of fascial space infections, (2) To determine the nature, size and extent of the odontogenic infections which involve the primary and secondary fascial spaces of the maxilla and the mandible (3) To evaluate the sensitivity of ultrasonography in determining whether the inflammatory process is in a stage of cellulitis or abscess and to thus determine the appropriate time for a surgical intervention during the course of the infection and to correlate the clinical and radiographic findings with the ultrasonographic findings and (4) to determine the treatment plan. Methodology: Thirty four patients with odontogenic infections which involved the superficial and the deep fascial spaces of the head and neck were subjected to ultrasonographic examinations over the suspected area in the transverse and axial directions to determine the stage of the infection, its anatomic location and the treatment plan. Results: Ultrasonography showed 95.7% sensitivity and 100% specificity as compared to the clinical and radiographic diagnoses and it proved to be an effective investigation modality in the diagnosis of fascial space infections. PMID:23814756

Nisha V., Aarthi; J., Parthiban; N., Santana; A.G, Giridhar; Devi B.K., Yashoda; Reddy S., Sujatha; N., Rakesh

2013-01-01

258

The Energetics of Aerobic versus Anaerobic Respiration.  

ERIC Educational Resources Information Center

Background information, laboratory procedures, and a discussion of the results of an experiment designed to investigate the difference in energy gained from the aerobic and anaerobic oxidation of glucose are presented. Sample experimental and calculated data are included. (CW)

Champion, Timothy D.; Schwenz, Richard W.

1990-01-01

259

Molecular Biology of Anaerobic Aromatic Biodegradation.  

National Technical Information Service (NTIS)

The molecular basis for the anaerobic degradation of benzoate and 4-hydroxybenzoate was investigated using the bacterium Rhodopseudomonas palustris as a model. A major thrust of the work involved cloning benzoate degradation and regulatory genes and assig...

C. S. Harwood

1996-01-01

260

Molecular Biology of Anaerobic Aromatic Biodegradation.  

National Technical Information Service (NTIS)

Aromatic acids are intermediates in the biodegradation of structurally diverse aromatic compounds, including lignin monomers and environmental pollutants, by many metabolic types of anaerobic bacteria. They are also the starting compounds for central path...

C. S. Harwood

1992-01-01

261

Genomic Analysis of Anaerobic Aromatic Degradation.  

National Technical Information Service (NTIS)

The anaerobic degradation of aromatic compounds is important for environmental bioremediation because substantial amounts of toxic aromatic compounds are produced industrially and make their way into anoxic groundwaters and sediments. Although the biodegr...

C. S. Harwood

2004-01-01

262

Anaerobic digestion of cattail by rumen cultures  

Microsoft Academic Search

The anaerobic digestion of aquatic plants could serve the dual roles for producing renewable energy and reducing waste. In this study, the anaerobic digestion of cattail (Typha latifolia linn), a lignocellulosic aquatic plant, by rumen microorganisms in batch cultures was investigated. At a substrate level of 12.4g\\/l volatile solids (VS) and pH 6.7, maximum VS conversion of 66% was achieved

Zhen-Hu Hu; Han-Qing Yu

2006-01-01

263

Anaerobic digestion and wastewater treatment systems  

Microsoft Academic Search

Upflow Anaerobic Sludge Bed (UASB) wastewater (pre-)treatment systems represent a proven sustainable technology for a wide range of very different industrial effluents, including those containing toxic\\/inhibitory compounds. The process is also feasible for treatment of domestic wastewater with temperatures as low as 14–16° C and likely even lower. Compared to conventional aerobic treatment systems the anaerobic treatment process merely offers

G. Lettinga

1995-01-01

264

Challenge of psychrophilic anaerobic wastewater treatment  

Microsoft Academic Search

Psychrophilic anaerobic treatment is an attractive option for wastewaters that are discharged at moderate to low temperature. The expanded granular sludge bed (EGSB) reactor has been shown to be a feasible system for anaerobic treatment of mainly soluble and pre-acidified wastewater at temperatures of 5–10°C. An organic loading rate (OLR) of 10–12 kg chemical oxygen demand (COD) per cubic meter

Gatze Lettinga; Salih Rebac; Grietje Zeeman

2001-01-01

265

Anaerobic electron acceptor chemotaxis in Shewanella putrefaciens  

NASA Technical Reports Server (NTRS)

Shewanella putrefaciens MR-1 can grow either aerobically or anaerobically at the expense of many different electron acceptors and is often found in abundance at redox interfaces in nature. Such redox interfaces are often characterized by very strong gradients of electron acceptors resulting from rapid microbial metabolism. The coincidence of S. putrefaciens abundance with environmental gradients prompted an examination of the ability of MR-1 to sense and respond to electron acceptor gradients in the laboratory. In these experiments, taxis to the majority of the electron acceptors that S. putrefaciens utilizes for anaerobic growth was seen. All anaerobic electron acceptor taxis was eliminated by the presence of oxygen, nitrate, nitrite, elemental sulfur, or dimethyl sulfoxide, even though taxis to the latter was very weak and nitrate and nitrite respiration was normal in the presence of dimethyl sulfoxide. Studies with respiratory mutants of MR-1 revealed that several electron acceptors that could not be used for anaerobic growth nevertheless elicited normal anaerobic taxis. Mutant M56, which was unable to respire nitrite, showed normal taxis to nitrite, as well as the inhibition of taxis to other electron acceptors by nitrite. These results indicate that electron acceptor taxis in S. putrefaciens does not conform to the paradigm established for Escherichia coli and several other bacteria. Carbon chemo-taxis was also unusual in this organism: of all carbon compounds tested, the only positive response observed was to formate under anaerobic conditions.

Nealson, K. H.; Moser, D. P.; Saffarini, D. A.

1995-01-01

266

Changes in gene expression of Actinobacillus pleuropneumoniae in response to anaerobic stress reveal induction of central metabolism and biofilm formation.  

PubMed

Actinobacillus pleuropneumoniae is an important porcine respiratory pathogen causing great economic losses in the pig industry worldwide. Oxygen deprivation is a stress that A. pleuropneumoniae will encounter during both early infection and the later, persistent stage. To understand modulation of A. pleuropneumoniae gene expression in response to the stress caused by anaerobic conditions, gene expression profiles under anaerobic and aerobic conditions were compared in this study. The microarray results showed that 631 genes (27.7% of the total ORFs) were differentially expressed in anaerobic conditions. Many genes encoding proteins involved in glycolysis, carbon source uptake systems, pyruvate metabolism, fermentation and the electron respiration transport chain were up-regulated. These changes led to an increased amount of pyruvate, lactate, ethanol and acetate in the bacterial cells as confirmed by metabolite detection. Genes encoding proteins involved in cell surface structures, especially biofilm formation, peptidoglycan biosynthesis and lipopolysaccharide biosynthesis were up-regulated as well. Biofilm formation was significantly enhanced under anaerobic conditions. These results indicate that induction of central metabolism is important for basic survival of A. pleuropneumoniae after a shift to an anaerobic environment. Enhanced biofilm formation may contribute to the persistence of this pathogen in the damaged anaerobic host tissue and also in the early colonization stage. These discoveries give new insights into adaptation mechanisms of A. pleuropneumoniae in response to environmental stress. PMID:24723105

Li, Lu; Zhu, Jiawen; Yang, Kui; Xu, Zhuofei; Liu, Ziduo; Zhou, Rui

2014-06-01

267

Anaerobic Nitrogen Fixers on Mars  

NASA Astrophysics Data System (ADS)

The conversion of atmospheric nitrogen gas to the protein of living systems is an amazing process of nature. The first step in the process is biological nitrogen fixation, the transformation of N2 to NH3. The phenomenon is crucial for feeding the billions of our species on Earth. On Mars, the same process may allow us to discover how life can adapt to a hostile environment, and render it habitable. Hostile environments also exist on Earth. For example, nothing grows in coal refuse piles due to the oxidation of pyrite and marcasite to sulfuric acid. Yet, when the acidity is neutralized, alfalfa and soybean plants develop root nodules typical of symbiotic nitrogen fixation with Rhizobium species possibly living in the pyritic material. When split open, these nodules exhibited the pinkish color of leghemoglobin, a protein in the nodule protecting the active nitrogen-fixing enzyme nitrogenase against the toxic effects of oxygen. Although we have not yet obtained direct evidence of nitrogenase activity in these nodules (reduction of acetylene to ethylene, for example), these findings suggested the possibility that nitrogen fixation was taking place in this hostile, non-soil material. This immediately raises the possibility that freeliving anaerobic bacteria which fix atmospheric nitrogen on Earth, could do the same on Mars.

Lewis, B. G.

2000-07-01

268

Anaerobic digestion of extruded OFMSW.  

PubMed

Organic fraction of municipal solid waste (OFMSW) was used to feed two pilot plants of 1000 l working in anaerobic conditions. The OFMSW had previously been treated using a system of extrusion which, due to exerted pressure, separates the undesired fractions of waste from organic waste and reduces the organic fraction in a kind of homogeneous jam. Pilot tests were performed in semi-continuous conditions with a stepwise progressive increase of the total solids content (TS) of the input material from 3% TS w/w (1.5 g VS l(-1) d(-1) organic loading rate) to 10% TS w/w (4.3 g VS l(-1) d(-1) organic loading rate) using activated sludge as diluting agent. The average specific biogas production obtained was 600 l kg(-1)VS. When the input TS content was increased to 10% w/w, the biogas average specific production went up to 800 l kg(-1)VS. The methane content in the biogas was always higher than 60% measured by volume. PMID:22074901

Novarino, Daniel; Zanetti, Maria Chiara

2012-01-01

269

Activation of Cholera Toxin Production by Anaerobic Respiration of Trimethylamine N-oxide in Vibrio cholerae*  

PubMed Central

Vibrio cholerae is a Gram-negative bacterium that causes cholera. Although the pathogenesis caused by this deadly pathogen takes place in the intestine, commonly thought to be anaerobic, anaerobiosis-induced virulence regulations are not fully elucidated. Anerobic growth of the V. cholerae strain, N16961, was promoted when trimethylamine N-oxide (TMAO) was used as an alternative electron acceptor. Strikingly, cholera toxin (CT) production was markedly induced during anaerobic TMAO respiration. N16961 mutants unable to metabolize TMAO were incapable of producing CT, suggesting a mechanistic link between anaerobic TMAO respiration and CT production. TMAO reductase is transported to the periplasm via the twin arginine transport (TAT) system. A similar defect in both anaerobic TMAO respiration and CT production was also observed in a N16961 TAT mutant. In contrast, the abilities to grow on TMAO and to produce CT were not affected in a mutant of the general secretion pathway. This suggests that V. cholerae may utilize the TAT system to secrete CT during TMAO respiration. During anaerobic growth with TMAO, N16961 cells exhibit green fluorescence when stained with 2?,7?-dichlorofluorescein diacetate, a specific dye for reactive oxygen species (ROS). Furthermore, CT production was decreased in the presence of an ROS scavenger suggesting a positive role of ROS in regulating CT production. When TMAO was co-administered to infant mice infected with N16961, the mice exhibited more severe pathogenic symptoms. Together, our results reveal a novel anaerobic growth condition that stimulates V. cholerae to produce its major virulence factor. PMID:23019319

Lee, Kang-Mu; Park, Yongjin; Bari, Wasimul; Yoon, Mi Young; Go, Junhyeok; Kim, Sang Cheol; Lee, Hyung-il; Yoon, Sang Sun

2012-01-01

270

Activation of cholera toxin production by anaerobic respiration of trimethylamine N-oxide in Vibrio cholerae.  

PubMed

Vibrio cholerae is a gram-negative bacterium that causes cholera. Although the pathogenesis caused by this deadly pathogen takes place in the intestine, commonly thought to be anaerobic, anaerobiosis-induced virulence regulations are not fully elucidated. Anerobic growth of the V. cholerae strain, N16961, was promoted when trimethylamine N-oxide (TMAO) was used as an alternative electron acceptor. Strikingly, cholera toxin (CT) production was markedly induced during anaerobic TMAO respiration. N16961 mutants unable to metabolize TMAO were incapable of producing CT, suggesting a mechanistic link between anaerobic TMAO respiration and CT production. TMAO reductase is transported to the periplasm via the twin arginine transport (TAT) system. A similar defect in both anaerobic TMAO respiration and CT production was also observed in a N16961 TAT mutant. In contrast, the abilities to grow on TMAO and to produce CT were not affected in a mutant of the general secretion pathway. This suggests that V. cholerae may utilize the TAT system to secrete CT during TMAO respiration. During anaerobic growth with TMAO, N16961 cells exhibit green fluorescence when stained with 2',7'-dichlorofluorescein diacetate, a specific dye for reactive oxygen species (ROS). Furthermore, CT production was decreased in the presence of an ROS scavenger suggesting a positive role of ROS in regulating CT production. When TMAO was co-administered to infant mice infected with N16961, the mice exhibited more severe pathogenic symptoms. Together, our results reveal a novel anaerobic growth condition that stimulates V. cholerae to produce its major virulence factor. PMID:23019319

Lee, Kang-Mu; Park, Yongjin; Bari, Wasimul; Yoon, Mi Young; Go, Junhyeok; Kim, Sang Cheol; Lee, Hyung-Il; Yoon, Sang Sun

2012-11-16

271

Appraisal of Anotox, a new anaerobic atmospheric detoxifying agent for use in anaerobic cabinets.  

PubMed Central

Using Clostridium sporogenes cultures, inhibitory effects of its gaseous metabolic end products on the activity of palladium Deoxo catalyst and on surface growth of some clinically significant anaerobes were demonstrated. A new product "Anotox" was shown to absorb these metabolites, which enabled uninhibited growth of anaerobes, and prolonged the life of the catalyst. PMID:7068916

Brazier, J S

1982-01-01

272

[Severe nosocomial infection of soft tissue in general surgery].  

PubMed

This paper aim is to emphasize the severity of soft tissue nosocomial infections, determined by anaerobic bacteria associated with Gram-negative aerobic bacteria: 50% mortality, higher economic costs, disabling morphologic and functional sequels. We present the pathogenic, clinical and therapeutically problems which characterize this type of postoperative infections. PMID:16106937

Vasile, I; Vîlcea, D; Persu, B; Neme?, R; Cheie, Mihaela; Calot?, F; Pa?alega, M; Me?in?, C; Curc?, T; Tra?c?, E; Scurtu, S

2005-01-01

273

Clostridium difficile infection and pseudomembranous colitis  

Microsoft Academic Search

Clostridium difficile causes a spectrum of diseases ranging from diarrhoea to pseudomembranous colitis, primarily in the hospitalized elderly, although community-acquired infection is probably under-documented. Host factors are increasingly recognized as critical determinants of disease expression. Exposure to antibiotics, particularly those adversely affecting anaerobic gut flora, appears to create a niche which is exploited by C. difficile. Several retrospective and intervention

Mark H Wilcox

2003-01-01

274

Clostridium difficile infection and pseudomembranous colitis  

Microsoft Academic Search

Clostridium difficile causes a spectrum of diseases ranging from diarrhoea to pseudomembranous colitis, primarily in the hospitalized elderly, although community-acquired infection is probably under-documented. Host factors are increasingly recognized as critical determinants of disease expression. Exposure to antibiotics, particularly those adversely affecting anaerobic gut flora, appears to create a niche which is exploited by C. difficile. Several retrospective and intervention

Mark H. Wilcox

275

Anaerobic energy metabolism in unicellular photosynthetic eukaryotes.  

PubMed

Anaerobic metabolic pathways allow unicellular organisms to tolerate or colonize anoxic environments. Over the past ten years, genome sequencing projects have brought a new light on the extent of anaerobic metabolism in eukaryotes. A surprising development has been that free-living unicellular algae capable of photoautotrophic lifestyle are, in terms of their enzymatic repertoire, among the best equipped eukaryotes known when it comes to anaerobic energy metabolism. Some of these algae are marine organisms, common in the oceans, others are more typically soil inhabitants. All these species are important from the ecological (O(2)/CO(2) budget), biotechnological, and evolutionary perspectives. In the unicellular algae surveyed here, mixed-acid type fermentations are widespread while anaerobic respiration, which is more typical of eukaryotic heterotrophs, appears to be rare. The presence of a core anaerobic metabolism among the algae provides insights into its evolutionary origin, which traces to the eukaryote common ancestor. The predicted fermentative enzymes often exhibit an amino acid extension at the N-terminus, suggesting that these proteins might be compartmentalized in the cell, likely in the chloroplast or the mitochondrion. The green algae Chlamydomonas reinhardtii and Chlorella NC64 have the most extended set of fermentative enzymes reported so far. Among the eukaryotes with secondary plastids, the diatom Thalassiosira pseudonana has the most pronounced anaerobic capabilities as yet. From the standpoints of genomic, transcriptomic, and biochemical studies, anaerobic energy metabolism in C. reinhardtii remains the best characterized among photosynthetic protists. This article is part of a Special Issue entitled: The evolutionary aspects of bioenergetic systems. PMID:22902601

Atteia, Ariane; van Lis, Robert; Tielens, Aloysius G M; Martin, William F

2013-02-01

276

Osteomyelitis in dogs and cats caused by anaerobic bacteria.  

PubMed

Localised osteomyelitis was diagnosed in 2 dogs and 2 cats. The disease was caused by fight wounds in 3 cases. Radiographic examination demonstrated a circumscribed zone of cortical bone lysis, sequestra and periosteal new bone. Each case was treated surgically by sequestrectomy and debridement. Infection was due mainly to anaerobic bacteria. The pathogenic bacteria isolated from the lesions of dogs were Actinomyces viscosus, Fusobacterium nucleatum and Bacteroides spp, and from the lesions in cats were Clostridium villosum , Peptostreptococcus anaerobius, Wolinella recta and Bacteroides gingivalis. As all the bacteria were sensitive to penicillin, each case was treated with penicillin and by irrigation of the wound. This resulted in resolution of the disease, within 4 weeks, in all cases. PMID:6732670

Johnson, K A; Lomas, G R; Wood, A K

1984-02-01

277

Urinary Tract Infection By Chromobacterium Violaceum  

PubMed Central

Chromobacterium violaceum, a facultative anaerobic proteobacterium, is particularly isolated from water and soil in tropical areas and has been implicated in few infections like septicemia, visceral abscesses, skin and soft tissue infections, meningitis and diarrhea. But urinary tract infection caused by it is very rare. Limited awareness about this pathogen and inappropriate antibiotic therapy contribute to a high mortality rate. Here, we describe an unusual case of urinary tract infection by Chromobacterium violaceum in a young immuno-competent male which was managed aggressively with proper antibiotics as per the culture sensitivity report. PMID:25302195

Otta, Sarita; Sahu, Kundan Kumar; Panda, Kirtika; Rout, Subhrajita

2014-01-01

278

ANAEROBIC BIOLOGICAL TREATMENT OF PRODUCED WATER  

SciTech Connect

During the production of oil and gas, large amounts of water are brought to the surface and must be disposed of in an environmentally sensitive manner. This is an especially difficult problem in offshore production facilities where space is a major constraint. The chief regulatory criterion for produced water is oil and grease. Most facilities have little trouble meeting this criterion using conventional oil-water separation technologies. However, some operations have significant amounts of naphthenic acids in the water that behave as oil and grease but are not well removed by conventional technologies. Aerobic biological treatment of naphthenic acids in simulated-produced water has been demonstrated by others; however, the system was easily overloaded by the large amounts of low-molecular-weight organic acids often found in produced waters. The objective of this research was to determine the ability of an anaerobic biological system to treat these organic acids in a simulated produced water and to examine the potential for biodegradation of the naphthenic acids in the anaerobic environment. A small fixed-film anaerobic biological reactor was constructed and adapted to treat a simulated produced water. The bioreactor was tubular, with a low-density porous glass packing material. The inocula to the reactor was sediment from a produced-water holding pond from a municipal anaerobic digester and two salt-loving methanogenic bacteria. During start-up, the feed to the reactor contained glucose as well as typical produced-water components. When glucose was used, rapid gas production was observed. However, when glucose was eliminated and the major organic component was acetate, little gas was generated. Methane production from acetate may have been inhibited by the high salt concentrations, by sulfide, or because of the lack, despite seeding, of microbes capable of converting acetate to methane. Toluene, a minor component of the produced water (0.1 g/L) was removed in the reactor. Batch tests were conducted to examine naphthenic acid biodegradability under several conditions. The conditions used were seed from the anaerobic reactor, wetland sediments under aerobic and anaerobic conditions, and a sterile control. The naphthenic acid was from a commercial source isolated from Gulf Coast petroleum as was dosed at 2 mg/mL. The incubations were for 30 days at 30 C. The results showed that the naphthenic acids were not biodegraded under anaerobic conditions, but were degraded under aerobic conditions. Despite poor performance of the anaerobic reactor, it remains likely that anaerobic treatment of acetate, toluene, and, potentially, other produced-water components is feasible.

John R. Gallagher

2001-07-31

279

Multiple bilateral supernumerary mandibular premolars in a non-syndromic patient with associated orthokeratised odontogenic cyst- A case report and review of literature.  

PubMed

Multiple supernumerary teeth are very rare, accounting for less than 1% of cases. They are commonly associated with syndromes like Gardner's syndrome and cleidocranial dysostosis and cleft lip and palate. Non-syndromic multiple supernumerary teeth have a predilection to occur in the mandibular premolar region. Orthokeratinized odontogenic cyst (OOC) is a relatively uncommon developmental cyst comprising about 10% of the cases that had been previously implied as odontogenic keratocysts. More than half of the cases of OOC are associated with impacted tooth; but not a single case of OOC associated with supernumerary teeth is reported. Hence, the purpose of this article is to report the first case of multiple supernumerary mandibular premolars associated with OOC in a 35-year-old male and to review the literature associated with multiple bilateral supernumerary mandibular premolars. PMID:23230374

Kasat, Vikrant O; Saluja, Harish; Kalburge, Jitendra V; Kini, Yogesh; Nikam, Atul; Laddha, Ruchi

2012-09-01

280

Multiple bilateral supernumerary mandibular premolars in a non-syndromic patient with associated orthokeratised odontogenic cyst- A case report and review of literature  

PubMed Central

Multiple supernumerary teeth are very rare, accounting for less than 1% of cases. They are commonly associated with syndromes like Gardner's syndrome and cleidocranial dysostosis and cleft lip and palate. Non-syndromic multiple supernumerary teeth have a predilection to occur in the mandibular premolar region. Orthokeratinized odontogenic cyst (OOC) is a relatively uncommon developmental cyst comprising about 10% of the cases that had been previously implied as odontogenic keratocysts. More than half of the cases of OOC are associated with impacted tooth; but not a single case of OOC associated with supernumerary teeth is reported. Hence, the purpose of this article is to report the first case of multiple supernumerary mandibular premolars associated with OOC in a 35-year-old male and to review the literature associated with multiple bilateral supernumerary mandibular premolars. PMID:23230374

Kasat, Vikrant O.; Saluja, Harish; Kalburge, Jitendra V.; Kini, Yogesh; Nikam, Atul; Laddha, Ruchi

2012-01-01

281

Submerged filter biotreatment of hazardous leachate in aerobic, anaerobic, and anaerobic/aerobic systems  

SciTech Connect

Aerobic, anaerobic and anaerobic/aerobic biotreatment of an industrial hazardous waste landfill leachate was evaluated in bench scale biofilm reactor systems operated under steady-and non-steady-state conditions. The leachate contained volatile and semi-volatile organics that exceeded the best-demonstrated-available-technology (BDAT) standard established for multi-source leachate wastewater under the Resources Conservation and Recovery Act (RCRA). The influent leachate stream was continuously applied to three parallel systems: (1) an upflow anaerobic filter followed by a submerged aerobic filter, both plastic packing, (2) an anaerobic granular activated carbon column, and (3) an upflow, plastic packed aerobic filter. All systems achieved steady-state COD removals of 66-82 percent. The sequential anaerobic/aerobic filter system was most resistant to hydraulic and organic shock loading, whereas the aerobic filter performance deteriorated significantly. Though transformations of specific chemical compounds were achieved in both anaerobic and aerobic treatment, the sequential anaerobic/aerobic system was cost effective for meeting BDAT standards for hazardous organics. 25 refs., 6 figs., 15 tabs.

Smith, D.P. [Utah State Univ., Logan, UT (United States)

1995-12-31

282

Wingate Anaerobic Test peak power and anaerobic capacity classifications for men and women intercollegiate athletes.  

PubMed

The Wingate Anaerobic Test (WAnT) has been established as an effective tool in measuring both muscular power and anaerobic capacity in a 30-second time period; however, there are no published normative tables by which to compare WAnT performance in men and women intercollegiate athletics. The purpose of this study was to develop a classification system for anaerobic peak power and anaerobic capacity for men and women National Collegiate Athletic Association (NCAA) Division I college athletes using the WAnT. A total of 1,585 (1,374 men and 211 women) tests were conducted on athletes ranging from the ages of 18 to 25 years using the WAnT. Absolute and relative peak power and anaerobic capacity data were recorded. One-half standard deviations were used to set up a 7-tier classification system (poor to elite) for these assessments. These classifications can be used by athletes, coaches, and practitioners to evaluate anaerobic peak power and anaerobic capacity in their athletes. PMID:19910814

Zupan, Michael F; Arata, Alan W; Dawson, Letitia H; Wile, Alfred L; Payn, Tamara L; Hannon, Megan E

2009-12-01

283

Biochemistry and physiology of anaerobic bacteria  

SciTech Connect

We welcome you to The Power of Anaerobes. This conference serves two purposes. One is to celebrate the life of Harry D. Peck, Jr.,who was born May 18, 1927 and would have celebrated his 73rd birthday at this conference. He died November 20, 1998. The second is to gather investigators to exchange views within the realm of anaerobic microbiology, an area in which tremendous progress has been seen during recent years. It is sufficient to mention discoveries of a new form of life (the archaea), hyper or extreme thermophiles, thermophilic alkaliphiles and anaerobic fungi. With these discoveries has come a new realization about physiological and metabolic properties of microorganisms, and this in turn has demonstrated their importance for the development, maintenance and sustenance of life on Earth.

NONE

2000-05-18

284

Use of biochars in anaerobic digestion.  

PubMed

This study investigated the behavior of biochars from pyrolysis (pyrochar) and hydrothermal carbonization (hydrochar) in anaerobic digestion regarding their degradability and their effects on biogas production and ammonia inhibition. A batch fermentation experiment (42°C, 63 days) was conducted in 100mL syringes filled with 30 g inoculum, 2g biochar and four levels of total ammonium nitrogen (TAN). For pyrochar, no clear effect on biogas production was observed, whereas hydrochar increased the methane yield by 32%. This correlates with the hydrochar's larger fraction of anaerobically degradable carbon (10.4% of total carbon, pyrochar: 0.6%). Kinetic and microbiota analyses revealed that pyrochar can prevent mild ammonia inhibition (2.1 g TANk g(-1)). Stronger inhibitions (3.1-6.6 g TAN kg(-1)) were not mitigated, neither by pyrochar nor by hydrochar. Future research should pay attention to biochar-microbe interactions and the effects in continuously-fed anaerobic digesters. PMID:24859210

Mumme, Jan; Srocke, Franziska; Heeg, Kathrin; Werner, Maja

2014-07-01

285

Original article Anaerobic bacteria isolated from the alimentary canals  

E-print Network

bee (Megachile rotundata) larvae under strict anaerobic conditions. In all 3 years of the study, small, Ascosphaera aggregata. © Inra/DIB/- AGIB/Elsevier, Paris Megachile rotundata / larvae / alimentary canals / anaerobic microflora 1. INTRODUCTION Alfalfa leafcutting bees (Megachile rotundata Fabricius

Paris-Sud XI, Université de

286

ANAEROBIC TRANSFORMATION PROCESSES: A REVIEW OF THE MICROBIOLOGICAL LITERATURE  

EPA Science Inventory

The purpose of the review is to evaluate and summarize available information about the role of microorganisms in the anaerobic transformation of xenobiotic compounds in natural environments. The review focuses on the anaerobic transformation of xenobiotic compounds and natural st...

287

Diversity of Anaerobic Dehalogenation in Estuarine and Marien Sediment.  

National Technical Information Service (NTIS)

The overall objective of the project was to characterize the activity and interactions of diverse anaerobic microbial communities involved in dehalogenation in marine sediments. Understanding the role of anaerobic respiratory processes and different micro...

M. M. Haggblom

1998-01-01

288

Anaerobic alkalithermophiles, a novel group of extremophiles  

Microsoft Academic Search

Although some anaerobic and aerobic mesophiles have long been known to grow at alkaline pH (above 9.5), little was known\\u000a until recently about thermophilic alkaliphiles, termed now alkalithermophiles. This minireview describes presently known and\\u000a recently validly described anaerobic alkalithermophilic bacteria (pHopt\\u000a 55C > 8.5; Topt > 55°C) and alkalitolerant thermophiles (pHopt\\u000a 55C max\\u000a 55C above 9.0). Some of these are

Juergen Wiegel

1998-01-01

289

Anaerobic and aerobic bacteriology of the saliva and gingiva from 16 captive Komodo dragons (Varanus komodoensis): new implications for the "bacteria as venom" model.  

PubMed

It has been speculated that the oral flora of the Komodo dragon (Varanus komodoensis) exerts a lethal effect on its prey; yet, scant information about their specific oral flora bacteriology, especially anaerobes, exists. Consequently, the aerobic and anaerobic oral bacteriology of 16 captive Komodo dragons (10 adults and six neonates), aged 2-17 yr for adults and 7-10 days for neonates, from three U.S. zoos were studied. Saliva and gingival samples were collected by zoo personnel, inoculated into anaerobic transport media, and delivered by courier to a reference laboratory. Samples were cultured for aerobes and anaerobes. Strains were identified by standard methods and 16S rRNA gene sequencing when required. The oral flora consisted of 39 aerobic and 21 anaerobic species, with some variation by zoo. Adult dragons grew 128 isolates, including 37 aerobic gram-negative rods (one to eight per specimen), especially Enterobacteriaceae; 50 aerobic gram-positive bacteria (two to nine per specimen), especially Staphylococcus sciuri and Enterococcusfaecalis, present in eight of 10 and nine of 10 dragons, respectively; and 41 anaerobes (one to six per specimen), especially clostridia. All hatchlings grew aerobes but none grew anaerobes. No virulent species were isolated. As with other carnivores, captive Komodo oral flora is simply reflective of the gut and skin flora of their recent meals and environment and is unlikely to cause rapid fatal infection. PMID:23805543

Goldstein, Ellie J C; Tyrrell, Kerin L; Citron, Diane M; Cox, Cathleen R; Recchio, Ian M; Okimoto, Ben; Bryja, Judith; Fry, Bryan G

2013-06-01

290

The IWA Anaerobic Digestion Model No 1 (ADM1)  

Microsoft Academic Search

The IWA Anaerobic Digestion Modelling Task Group was established in 1997 at the 8th World Congress on Anaerobic Digestion (Sendai, Japan) with the goal of developing a generalised anaerobic digestion model. The structured model includes multiple steps describing biochemical as well as physicochemical processes. The biochemical steps include disintegration from homogeneous particulates to carbohydrates, proteins and lipids; extracellular hydrolysis of

D. J. Batstone; J. Keller; I. Angelidaki; S. V. Kalyuzhnyi; S. G. Pavalostathis; A. Rozzi; W. T. M. Sanders; H. Siegrist; V. A. Vavilin

2002-01-01

291

Parameter identification in dynamical models of anaerobic waste water treatment  

E-print Network

Parameter identification in dynamical models of anaerobic waste water treatment T.G. Muuller a,*, N how to solve them, we analyze two different second order models for anaerobic waste water treatment identifiability; Confidence intervals; Waste water treatment processes 1. Introduction Anaerobic waste water

Timmer, Jens

292

Aerobic and anaerobic biodegradation of nitrilotriacetate in subsurface soils  

Microsoft Academic Search

Studies were conducted to characterize mineralization of nitrilotriacetate (NTA) in subsurface soils under aerobic and anaerobic conditions. Chemical (redox indicator, resazurin) and biological (dentrification) markers were used as indicators of anaerobic conditions in the test system. The indigenous microflora in subsurface soils previously exposed to septage containing NTA were able to rapidly mineralize NTA under aerobic and anaerobic conditions. The

T WARD

1986-01-01

293

Assessing Enhanced Anaerobic and Intrinsic Aerobic Biodegradation of Trichloroethene  

Microsoft Academic Search

Biodegradation of chloroethenes can proceed either anaerobically or aerobically; however, the techniques for monitoring the two pathways are quite different. At the Idaho National Engineering and Environmental Laboratory's Test Area North (TAN, a combination of anaerobic and aerobic biodegradation of trichloroethene (TCE) is being employed for restoration of a large plume of contaminated groundwater. During stimulation of anaerobic biodegradation of

K. S. Sorenson; R. L. Ely; J. P. Martin; L. Alvarez-Cohen; M. E. Kauffman

2001-01-01

294

The Influence of Hydration on Anaerobic Performance: A Review  

ERIC Educational Resources Information Center

This review examines the influence of dehydration on muscular strength and endurance and on single and repeated anaerobic sprint bouts. Describing hydration effects on anaerobic performance is difficult because various exercise modes are dominated by anaerobic energy pathways, but still contain inherent physiological differences. The critical…

Kraft, Justin A.; Green, James M.; Bishop, Phillip A.; Richardson, Mark T.; Neggers, Yasmin H.; Leeper, James D.

2012-01-01

295

Studies on SAGO wastewater treatment using anaerobic rotating biological contactor  

Microsoft Academic Search

Experimental studies were done in a laboratory scale Anaerobic Rotating Biological Contactor (RBC), for treatment of Synthetic sago wastewater. This paper describes the development and laboratory testing of an Anaerobic RBC process that couples the advantages of the fixed film horizontal flow RBC process with the high strength, starch degradation capabilities of anaerobic systems. The reactor was operated at ambient

P. Sujana; T. K. Ramanujam

1997-01-01

296

Thermochemical liquidization of anaerobically digested and dewatered sludge and anaerobic retreatment  

Microsoft Academic Search

The pretreatment effect of thermochemical liquidization for the anaerobic retreatment of anaerobically digested and dewatered sludge was studied. The digested sludge (dry matter; 15.7%) was thermochemically liquidized at 175°C and 4 MPa with a holding time of 1 h. The liquidized sludge was separated by centrifugation to produce a supernatant of 44.7% (w\\/w) and precipitate of 52.3%. The liquidized sludge

Shigeki Sawayama; Seiichi Inoue; Kenichiro Tsukahara; Tomoko Ogi

1996-01-01

297

Anaerobic utilization of essential oils bydenitrifying bacteria  

Microsoft Academic Search

Plant volatile organic compounds are a major carbonsource in nature. We studied the degradability ofthese substances by anaerobic microorganisms inenrichment cultures with representative essential oilsas organic substrates and nitrate as electronacceptor. Lemon and pine needle oil supportedmicrobial growth in the presence of pure oil, whereasparsley seed, camphor, sage, fennel, and mint oilsupported growth only when the essential oils weredissolved in

Jens Harder; Udo Heyen

2000-01-01

298

New perspectives on anaerobic methane oxidation  

Microsoft Academic Search

Summary Anaerobic methane oxidation is a globally important but poorly understood process. Four lines of evidence have recently improved our understanding of this process. First, studies of recent marine sediments indicate that a consortium of methanogens and sulphate-reducing bacteria are responsible for anae- robic methane oxidation; a mechanism of 'reverse methanogenesis' was proposed, based on the prin- ciple of interspecies

David L. Valentine; William S. Reeburgh

2000-01-01

299

UNCORRECTEDPROOF Assessment of anaerobic benzene degradation  

E-print Network

potential was demonstrated. This is the first report of the use of real-time quantitative PCR for forensic on intrinsic anaerobic bioremediation processes that proceed without human intervention, and has been selected processes (rather than dilution or sorption) are effective at a given site (USEPA, 1998b). Although

Alvarez, Pedro J.

300

ANAEROBIC BIODEGRADABILITY OF NON-PETROLEUM OILS.  

EPA Science Inventory

Research has demonstrated that vegetable oils are amenable to anaerobic biodegradation. This is in contrast to petroleum oils. Vegetable oils are already oxygenated because they are composed of fatty acids and glycerols, which contribute to the biodegradability. A strategy has be...

301

Anaerobic digestion of crude glycerol: a review  

Microsoft Academic Search

Several researchers have used crude glycerol as a source of substrate for methane production and power generation, which is a way of adding value to this residue that has a high chemical oxygen demand (COD) and is rich in impurities. This review article summarizes recent data and discussions on the use of crude glycerol as substrate and co-substrate for anaerobic

M. B. Viana; A. V. Freitas; R. C. Leitão; G. A. S. Pinto; S. T. Santaella

2012-01-01

302

Monitoring the Atmosphere in an Anaerobic Chamber  

PubMed Central

The Couloximeter, a fuel cell designed to measure trace amounts of oxygen, was used to monitor the atmosphere in an anaerobic chamber. The device, easy to operate and to maintain, allowed both major and minor fluctuations in oxygen concentration to be measured. Using a hose attached to the outlet within the box, defective (ruptured) gloves were consistently distinguishable from intact gloves. PMID:16350004

Sudo, Sara Z.; Hersch, Paul A.

1974-01-01

303

Anaerobic Electron Acceptor Chemotaxis in Shewanella putrefaciens  

Microsoft Academic Search

Shewanella putrefaciensMR-1 can grow either aerobically or anaerobically at the expense of many different electron acceptors and is often found in abundance at redox interfaces in nature. Such redox interfaces are often characterized by very strong gradients of electron acceptors resulting from rapid microbial metabolism. The coincidence of S. putrefaciens abundance with environmental gradients prompted an examination of the ability

KENNETH H. NEALSON; DUANE P. MOSER; ANDDAAD A. SAFFARINI

1995-01-01

304

Hemicellulases from anaerobic thermophiles. Progress report  

SciTech Connect

The longterm goal of this research effort is to obtain an anaerobic thermophilic bacterium that efficiently converts various hemicellulose-containing biomass to ethanol over a broad pH range. The strategy is to modify the outfit and regulation of the rate-limiting xylanases, glycosidases and xylan esterases in the ethanologenic, anaerobic thermophile Thermoanaerobacter ethanolicus, which grows between pH 4.5 and 9.5. Although it utilizes xylans, the xylanase, acetyl(xylan) esterase and O-methylglucuronidase activities in T. ethanolicus are barely measurable and regarded as the rate limiting steps in its xylan utilization. Thus, and also due to the presently limited knowledge of hemicellulases in anaerobic thermophiles, we characterize the hemicellulolytic enzymes from this and other anaerobic thermophiles as enzyme donors. Beside the active xylosidase/arabinosidase from T. ethanolicus, exhibiting the two different activities, we characterized 2 xylosidases, two acetyl(xylan) esterases, and an O-methylglucuronidase from Thermoanaerobacterium spec. We will continue with the characterization of xylanases from novel isolated slightly acidophilic, neutrophilic and slightly alkalophilic thermophiles. We have cloned, subcloned and partially sequenced the 165,000 Da (2 x 85,000) xylosidase/arabinosidase from T. ethanolicus and started with the cloning of the esterases from Thermoanaerobacterium spec. Consequently, we will develop a shuttle vector and continue to apply electroporation of autoplasts as a method for cloning into T. ethanolicus.

Wiegel, J.

1994-05-01

305

Continuous Drip Flow System to Develop Biofilm of E. faecalis under Anaerobic Conditions  

PubMed Central

Purpose. To evaluate a structurally mature E. faecalis biofilm developed under anaerobic/dynamic conditions in an in vitro system. Methods. An experimental device was developed using a continuous drip flow system designed to develop biofilm under anaerobic conditions. The inoculum was replaced every 24 hours with a fresh growth medium for up to 10 days to feed the system. Gram staining was done every 24 hours to control the microorganism purity. Biofilms developed under the system were evaluated under the scanning electron microscope (SEM). Results. SEM micrographs demonstrated mushroom-shaped structures, corresponding to a mature E. faecalis biofilm. In the mature biofilm bacterial cells are totally encased in a polymeric extracellular matrix. Conclusions. The proposed in vitro system model provides an additional useful tool to study the biofilm concept in endodontic microbiology, allowing for a better understanding of persistent root canal infections. PMID:25371913

Gonzalez, Ana Maria; Corpus, Erika; Silva-Herzog, Daniel; Aragon-Piña, Antonio; Cohenca, Nestor

2014-01-01

306

Bacteremic skin and soft tissue infection caused by Prevotella loescheii  

PubMed Central

Background Anaerobes are a major component of gut flora. They play an important role in the pathogenesis of infections resulting from breaches in mucus membranes. Because of the difficulties in cultivating and identifying it, their role continues to be undermined. The purpose of this paper is to report a case of Prevotella loescheii bacteremic skin and soft tissue infection and review the literature. Case presentation A 42-year-old Caucasian man was admitted for an elective bariatric surgery. A lengthy intensive care unit stay and buttocks decubitus ulcers complicated his post-operative course. After being transferred to a long-term care facility, the decubitus ulcer became secondarily infected with multiple bacteria including P. loescheii; an anaerobe that grew in blood and wound cultures. The patient was treated successfully with aggressive surgical debridement, antibiotics and subsequent wound care. Conclusion P. loescheii colonizes the gut and plays an important role in periodontal infections. In rare occasions and under suitable circumstances, it can infect skin and soft tissues as well as joints. Given the difficulties in isolating anaerobes in the microbiology lab, considering this bacterium alongside other anaerobes in infections of devitalized tissue is indicated even if cultures were reported negative. PMID:24661318

2014-01-01

307

Comparative in vitro activity of PH-027 versus linezolid and other anti-anaerobic antimicrobials against clinical isolates of Clostridium difficile and other anaerobic bacteria.  

PubMed

PH-027 is a new 5-triazole oxazolidinone synthesized in our laboratories, which shows strong activity against gram-positive aerobic bacteria including clinical isolates. The objective of this study was to investigate the in vitro activity of this compound in comparison with linezolid and other antibiotics against gram-positive and gram-negative anaerobes. The in vitro activity of PH-027 in comparison with those of linezolid and other antimicrobial agents was evaluated against 201 clinical isolates of gram-positive and gram-negative anaerobic bacteria by agar dilution and Etest methods. PH-027 showed excellent activity, with minimum inhibitory concentrations (MIC) in the range of 0.12-4.0 microg/ml against all isolates; MIC90s being 4.0, 1.0, 2.0, 2.0 and 2.0 microg/ml against Clostridium difficile, Peptostreptococcus spp., Bacteroides fragilis, Prevotella bivia and Fusobacterium spp. respectively. In comparison, linezolid had MIC in the range of 0.5-4.0 microg/ml against all isolates, with MIC90s of 2.0, 4.0, 4.0, 4.0 and 2.0 microg/ml against the same set of bacteria respectively. PH-027 demonstrated excellent in vitro activity that is superior to linezolid against Peptostreptococcus spp., B. fragilis and P. bivia. However, against C. difficile and Fusobacterium spp, PH-027 and linezolid showed comparable in vitro activity. Against all anaerobes, metronidazole, PH-027 and, to a lesser extent, linezolid had the most potent activity. From the results of in vitro susceptibility testing, both linezolid and PH-027 show promise in the treatment of anaerobic infections. PMID:12797385

Phillips, O A; Rotimi, V O; Jamal, W Y; Shahin, M; Verghese, T L

2003-04-01

308

Odontogenic Keratocysts Arise from Quiescent Epithelial Rests and Are Associated with Deregulated Hedgehog Signaling in Mice and Humans  

PubMed Central

Odontogenic keratocysts in humans are aggressive, noninflammatory jaw cysts that may harbor PTCH1 mutations, leading to constitutive activity of the embryonic Hedgehog (Hh) signaling pathway. We show here that epithelial expression of the Hh transcriptional effector Gli2 is sufficient for highly penetrant keratocyst development in transgenic mice. Mouse and human keratocysts expressed similar markers, leading to tooth misalignment, bone remodeling, and craniofacial abnormalities. We detected Hh target gene expression in epithelial cells lining keratocysts from both species, implicating deregulated Hh signaling in their development. Most mouse keratocysts arose from rests of Malassez—quiescent, residual embryonic epithelial cells that remain embedded in the periodontal ligament surrounding mature teeth. In Gli2-expressing mice, these rests were stimulated to proliferate, stratify, and form a differentiated squamous epithelium. The frequent development of keratocysts in Gli2-expressing mice supports the idea that GLI transcription factor activity mediates pathological responses to deregulated Hh signaling in humans. Moreover, Gli2-mediated reactivation of quiescent epithelial rests to form keratocysts indicates that these cells retain the capacity to function as progenitor cells on activation by an appropriate developmental signal. PMID:16936257

Grachtchouk, Marina; Liu, Jianhong; Wang, Aiqin; Wei, Lebing; Bichakjian, Christopher K.; Garlick, Jonathan; Paulino, Augusto F.; Giordano, Thomas; Dlugosz, Andrzej A.

2006-01-01

309

A Qualitative and Quantitative Analysis of AgNORs in Keratocystic Odontogenic Tumor, Unicystic Ameloblastoma and Multicystic Ameloblastoma  

PubMed Central

Aims: A comparative evaluation of proliferation activity in unicystic ameloblastoma (UA), multicystic ameloblastoma (MA) and keratocystic odontogenic tumor (KCOT) using silver staining technique. Settings and Design: In the present study 21 histopathologically confirmed paraffin blocks,7 each of UA, MA and KCOT were selected and stained with silver nitrate. Materials and Methods: For quantitative analysis, 100 cells were counted at 1000x magnification for AgNORs and the mean value was calculated. Qualitative analysis of AgNORs included normal (oval shaped) and abnormal groups (bean shaped) in the lesion. Statistical Analysis: The statistical analysis of data was done by a specialist statistician using two way ANOVA and multiple comparisons with Tukey’s test in advanced excel. Results: The AgNOR count was more in KCOT when compared to MA and UA with the pattern of distribution of AgNORs more in basal than in the parabasal layer in KCOT. The qualitative analysis showed small to large oval AgNOR’s in KCOT and few clusters in MA whereas in UA irregular clusters were seen. Conclusion: This concludes the expediency of AgNOR staining in reflecting the high proliferation rate and a more aggressive behavior of KCOT in comparison to MA and UA which signifies requirement of a more hostile surgical approach in KCOT to avoid recurrences following different treatment modalities. PMID:25386440

Udayashankar, Urmila; Guduru, Vijay Srinivasvas; Ramprasad, V V S; Ramisetty, Sabitha Devi; Namala, Srilekha; Badavath, Kiran Kumar Naik

2014-01-01

310

In situ detection of anaerobic alkane metabolites in subsurface environments.  

PubMed

Alkanes comprise a substantial fraction of crude oil and refined fuels. As such, they are prevalent within deep subsurface fossil fuel deposits and in shallow subsurface environments such as aquifers that are contaminated with hydrocarbons. These environments are typically anaerobic, and host diverse microbial communities that can potentially use alkanes as substrates. Anaerobic alkane biodegradation has been reported to occur under nitrate-reducing, sulfate-reducing, and methanogenic conditions. Elucidating the pathways of anaerobic alkane metabolism has been of interest in order to understand how microbes can be used to remediate contaminated sites. Alkane activation primarily occurs by addition to fumarate, yielding alkylsuccinates, unique anaerobic metabolites that can be used to indicate in situ anaerobic alkane metabolism. These metabolites have been detected in hydrocarbon-contaminated shallow aquifers, offering strong evidence for intrinsic anaerobic bioremediation. Recently, studies have also revealed that alkylsuccinates are present in oil and coal seam production waters, indicating that anaerobic microbial communities can utilize alkanes in these deeper subsurface environments. In many crude oil reservoirs, the in situ anaerobic metabolism of hydrocarbons such as alkanes may be contributing to modern-day detrimental effects such as oilfield souring, or may lead to more beneficial technologies such as enhanced energy recovery from mature oilfields. In this review, we briefly describe the key metabolic pathways for anaerobic alkane (including n-alkanes, isoalkanes, and cyclic alkanes) metabolism and highlight several field reports wherein alkylsuccinates have provided evidence for anaerobic in situ alkane metabolism in shallow and deep subsurface environments. PMID:23761789

Agrawal, Akhil; Gieg, Lisa M

2013-01-01

311

In situ detection of anaerobic alkane metabolites in subsurface environments  

PubMed Central

Alkanes comprise a substantial fraction of crude oil and refined fuels. As such, they are prevalent within deep subsurface fossil fuel deposits and in shallow subsurface environments such as aquifers that are contaminated with hydrocarbons. These environments are typically anaerobic, and host diverse microbial communities that can potentially use alkanes as substrates. Anaerobic alkane biodegradation has been reported to occur under nitrate-reducing, sulfate-reducing, and methanogenic conditions. Elucidating the pathways of anaerobic alkane metabolism has been of interest in order to understand how microbes can be used to remediate contaminated sites. Alkane activation primarily occurs by addition to fumarate, yielding alkylsuccinates, unique anaerobic metabolites that can be used to indicate in situ anaerobic alkane metabolism. These metabolites have been detected in hydrocarbon-contaminated shallow aquifers, offering strong evidence for intrinsic anaerobic bioremediation. Recently, studies have also revealed that alkylsuccinates are present in oil and coal seam production waters, indicating that anaerobic microbial communities can utilize alkanes in these deeper subsurface environments. In many crude oil reservoirs, the in situ anaerobic metabolism of hydrocarbons such as alkanes may be contributing to modern-day detrimental effects such as oilfield souring, or may lead to more beneficial technologies such as enhanced energy recovery from mature oilfields. In this review, we briefly describe the key metabolic pathways for anaerobic alkane (including n-alkanes, isoalkanes, and cyclic alkanes) metabolism and highlight several field reports wherein alkylsuccinates have provided evidence for anaerobic in situ alkane metabolism in shallow and deep subsurface environments. PMID:23761789

Agrawal, Akhil; Gieg, Lisa M.

2013-01-01

312

Evaluation of the Oxyrase OxyPlate Anaerobe Incubation System  

PubMed Central

The Oxyrase OxyPlate anaerobe incubation system was evaluated for its ability to support the growth of clinically significant anaerobic bacteria previously identified by the Anaerobe Reference Laboratory at the Centers for Disease Control and Prevention. The results were compared with those obtained with conventional anaerobe blood agar plates incubated in an anaerobe chamber. We tested 251 anaerobic bacterial strains. Plates were read at 24, 48, and 72 h; growth was scored by a numerical coding system that combines the degree of growth and the colony size. Organisms (number of strains tested) used in this study were Actinomyces (32), Anaerobiospirillum (8), Bacteroides (39), Campylobacter (8), Clostridium (96), Fusobacterium (12), Leptotrichia (8), Mobiluncus (8), Peptostreptococcus (16), and Propionibacterium (24). At 24 h, 101 (40.2%) of the 251 strains tested showed better growth with the anaerobe chamber than with the OxyPlate system, 10 (4.1%) showed better growth with the OxyPlate system, and the remaining 140 (55.8%) showed equal growth with both systems. At 48 h, 173 (68.9%) showed equal growth with both systems, while 78 (31.1%) showed better growth with the anaerobe chamber. At 72 h, 176 (70.1%) showed equal growth with both systems, while 75 (29.9%) showed better growth with the anaerobe chamber. The OxyPlate system performed well for the most commonly isolated anaerobes but was inadequate for some strains. These results indicate that the Oxyrase OxyPlate system was effective in creating an anaerobic atmosphere and supporting the growth of anaerobic bacteria within 72 h. OxyPlates would be a useful addition to the clinical microbiology laboratory lacking resources for traditional anaerobic culturing techniques. PMID:10655335

Wiggs, Lois S.; Cavallaro, Joseph J.; Miller, J. Michael

2000-01-01

313

Nitrification of anaerobically treated coal gasifier effluent  

SciTech Connect

Coal gasifier effluent with high phenol, cresols and ammonia concentrations and lower amounts of cyanide, thiocyanate and other organic compounds was nitrified after treatment in an anaerobic fluidised-bed granular activated carbon filter. The single-stage biological nitrification system was operated at a solids retention time of 31 days and a hydraulic retention time of 18-30 hours. Removal efficiencies were 97% for total Kjeldahl nitrogen, 91% for TOC and 85% for COD; residual phenol and o-cresol were completely removed and removal of residual m-cresol and p-cresol depended on concentration. The nitrification process was inhibited by more than 15 mg/l of m-cresol and p-cresol, but this could be eliminated by addition of powdered activated carbon or periodic replacement of a portion of the granular activated carbon in the anaerobic filter.

Lu, F.

1984-09-01

314

New perspectives on anaerobic methane oxidation.  

PubMed

Anaerobic methane oxidation is a globally important but poorly understood process. Four lines of evidence have recently improved our understanding of this process. First, studies of recent marine sediments indicate that a consortium of methanogens and sulphate-reducing bacteria are responsible for anaerobic methane oxidation; a mechanism of 'reverse methanogenesis' was proposed, based on the principle of interspecies hydrogen transfer. Second, studies of known methanogens under low hydrogen and high methane conditions were unable to induce methane oxidation, indicating that 'reverse methanogenesis' is not a widespread process in methanogens. Third, lipid biomarker studies detected isotopically depleted archaeal and bacterial biomarkers from marine methane vents, and indicate that Archaea are the primary consumers of methane. Finally, phylogenetic studies indicate that only specific groups of Archaea and SRB are involved in methane oxidation. This review integrates results from these recent studies to constrain the responsible mechanisms. PMID:11233156

Valentine, D L; Reeburgh, W S

2000-10-01

315

Anaerobic Biodegradation of Organic Chemicals in Groundwater  

NSDL National Science Digital Library

The "Anaerobic Biodegradation of Organic Chemicals in Groundwater" report and database are available at this site. The report (.pdf format), by Syracuse Research Corporation (SRC), reviews anaerobic groundwater biodegradation literature "for 44 common organic chemicals (including BTEX, chlorinated aliphatic compounds, phenolic compounds, common freons, ketones, organic acids, and polychlorinated aromatic hydrocarbons)" and provides biodegradation rate constants based on these studies. The database, which may be downloaded (.zip format), contains information about the site, including location and type, sampling protocol and analysis, type of study, compound status, "pH, temperature, dissolved oxygen concentrations, redox conditions, initial and final concentrations of the compound, a published or calculated rate constant, length of the study, lag period, control results, general comments, and an abbreviated reference."

Aronson, Dallas.; Howard, Philip H.

316

FCPP application to utilize anaerobic digester gas  

SciTech Connect

Toshiba and a municipal organization of Yokohama city are jointly conducting a program to utilize ADG (Anaerobic Digester Gas) more effectively. ADG which contains about 60% methane is produced by anaerobic digestion of waste water treatment sludge and has been used as an energy source for heating digestion tanks in sewage treatment plants and/or for combustion engine fuel. This program is focused on operating a commercial Phosphoric Acid Fuel Cell (PAFC) power plant on ADG because of its inherently high fuel efficiency and low emissions characteristics. According to the following joint program, we have successfully demonstrated an ADG fueled FCPP The success of this study promises that the ADG fueled FCPP, an environment-friendly power generation system, will be added to the line-up of PC25{trademark}C applications.

Nakayama, Yoshio; Kusama, Nobuyuki; Wada, Katsuya [Toshiba Corp., Tokyo (Japan)

1996-12-31

317

Cultivation of Anaerobic and Facultatively Anaerobic Bacteria from Spacecraft-Associated Clean Rooms?  

PubMed Central

In the course of this biodiversity study, the cultivable microbial community of European spacecraft-associated clean rooms and the Herschel Space Observatory located therein were analyzed during routine assembly operations. Here, we focused on microorganisms capable of growing without oxygen. Anaerobes play a significant role in planetary protection considerations since extraterrestrial environments like Mars probably do not provide enough oxygen for fully aerobic microbial growth. A broad assortment of anaerobic media was used in our cultivation strategies, which focused on microorganisms with special metabolic skills. The majority of the isolated strains grew on anaerobic, complex, nutrient-rich media. Autotrophic microorganisms or microbes capable of fixing nitrogen were also cultivated. A broad range of facultatively anaerobic bacteria was detected during this study and also, for the first time, some strictly anaerobic bacteria (Clostridium and Propionibacterium) were isolated from spacecraft-associated clean rooms. The multiassay cultivation approach was the basis for the detection of several bacteria that had not been cultivated from these special environments before and also led to the discovery of two novel microbial species of Pseudomonas and Paenibacillus. PMID:19363082

Stieglmeier, Michaela; Wirth, Reinhard; Kminek, Gerhard; Moissl-Eichinger, Christine

2009-01-01

318

Anaerobic degradation of cresols by denitrifying bacteria  

Microsoft Academic Search

The initial reactions in anaerobic metablism of methylphenols (cresols) and dimethylphenols were studied with denitrifying bacteria. A newly isolated strain, possibly a Paracoccus sp., was able to grow on o-or p-cresol as sole organic substrate with a generation time of 11 h; o-or p-cresol was completely oxidized to CO2 with nitrate being reduced to N2. A denitrifying Pseudomonas-like strain oxidized

Angelika Rudolphi; Andreas Tschech; Georg Fuchs

1991-01-01

319

ANAEROBIC AMMONIUM OXIDATION IN THE MARINE ENVIRONMENT  

Microsoft Academic Search

Oceanographers noticed already many years ago that far less ammonium accumulated in anoxic fjords and basins, than would be\\u000a expected from the stoichiometry of heterotrophic denitrification. It was suggested that this ‘missing’ ammonium was oxidized\\u000a with nitrate to freeN2. Since then several otherworkers have argued based on chemical profiles that ammonium is oxidized anaerobically in oxygen\\u000a deficient marine sediments and

Marcel M. M. Kuypers; Gaute Lavik; Bo Thamdrup

320

Microbial transformation of styrene by anaerobic consortia.  

PubMed

Methanogenic microbial consortia, originally enriched from anaerobic sewage sludge with ferulic acid or styrene (vinylbenzene) as sole organic carbon and energy sources, were used to study transformation of styrene under strictly anaerobic conditions. Styrene, which was added as the substrate in a range of concentrations from 0.1 to 10 mmol/l, was extensively degraded but no methane production was observed during incubation for eight months. The addition of yeast extract during the enrichment stage completely inhibited degradation of styrene. Gas chromatography (GC), gas chromatography/mass spectrometry (GC/MS), high performance liquid chromatography (HPLC) analyses of the culture fluid, and GC analyses of the anaerobic headspace, indicated that the transformation of this arylalkene was initiated through an oxidation-reduction reaction and that the favoured mechanism was most likely the addition of water across the double bond in the alkenyl side-chain. The degradation proceeded through to carbon dioxide, the final product. Benzoic acid and phenol were transient compounds found in highest concentrations in the spent culture fluid and are suggested as the key intermediates of the transformation process. The tentative routes of anaerobic transformation partially overlap with those previously proposed for aromatic hydrocarbons such as toluene. Several pure cultures, which were tentatively identified as Clostridium spp. and Enterobacter spp., were isolated from the styrene-degrading consortia. Two of these cultures were demonstrated to grow on styrene as sole carbon and energy source. Additionally, a pure culture of Enterobacter cloacae DG-6 (ATCC 35929) which had been isolated previously from the ferulate-degrading consortium, was shown to degrade styrene through to carbon dioxide. PMID:2272946

Grbi?-Gali?, D; Churchman-Eisel, N; Mrakovi?, I

1990-08-01

321

Anaerobic digestion of slaughterhouse by-products  

Microsoft Academic Search

Anaerobic digestion of animal by-products was investigated in batch and semi-continuously fed, reactor experiments at 55°C and for some experiments also at 37°C. Separate or mixed by-products from pigs were tested. The methane potential measured by batch assays for meat- and bone flour, fat, blood, hair, meat, ribs, raw waste were: 225, 497, 487, 561, 582, 575, 359, 619dm3kg?1 respectively,

Anette Hejnfelt; Irini Angelidaki

2009-01-01

322

Monitoring and Control of Anaerobic Reactors  

Microsoft Academic Search

The current status in monitoring and control of anaerobic reactors is reviewed. The influence of reactor design and waste\\u000a composition on the possible monitoring and control schemes is examined. After defining the overall control structure, and\\u000a possible control objectives, the possible process measurements are reviewed in detail. In the sequel, possible manipulated\\u000a variables, such as the hydraulic retention time, the

Peter F. Pind; Irini Angelidaki; Birgitte K. Ahring; Katerina Stamatelatou; Gerasimos Lyberatos

323

SHEWANELLA: NOVEL STRATEGIES FOR ANAEROBIC RESPIRATION  

Microsoft Academic Search

Metal-reducing members of the genus Shewanella are important components of the microbial community residing in redox-strati.ed freshwater and marine environments. Metal-reducing\\u000a gram-negative bacteria such as Shewanella, however, are presented with a unique physiological challenge: they are required to respire anaerobically on terminal electron\\u000a acceptors which are either highly insoluble (Fe(III)- and Mn(IV)-oxides) and reduced to soluble end-products or highly soluble

Thomas J. DiChristina; David J. Bates; Justin L. Burns; Jason R. Dale; Amanda N. Payne

324

Anaerobic methane oxidation on the Amazon shelf  

SciTech Connect

Anaerobic methane oxidation on the Amazon shelf is strongly controlled by dynamic physical sedimentation processes. Rapidly accumulating, physically reworked deltaic sediments characteristic of much of the shelf typically support what appear to be low rates of steady state anaerobic methane oxidation at depths of 5-8 m below the sediment-water interface. Methane oxidation in these cases is responsible for < {approximately}10% of the {Sigma}CO{sub 2} inventory in the oxidation zone and is limited largely by the steady-state diffusive flux of methane into the overlying sulfate reduction zone. In contrast, a large area of the shelf has been extensively eroded, reexposing once deeply buried (>10 m) methane-charged sediment directly to seawater. In this nonsteady-state situation, methane is a major source of recently produced {Sigma}CO{sub 2} and an important reductant for sulfate. These observations suggest that authigenic sedimentary carbonates derived from anaerobic methane oxidation may sometimes reflect physically enhanced nonsteady-state exposure of methane to sulfate in otherwise biogeochemically unreactive deposits. The concentration profiles of CH{sub 4}, SO{sub 4}{sup =}, and {Sigma}CO{sub 2} in the eroded deposit were reproduced by a coupled reaction-transport model. This area of the shelf was reexposed to seawater approximately 5-10 years ago based on the model results and the assumption that the erosion of the deposit occurred as a single event that has now ceased. The necessary second order rate constant for anaerobic methane oxidation was {le}0.1 mM{sup -1} d{sup -1}.

Blair, N.E. [North Carolina State Univ., Raleigh, NC (United States)] [North Carolina State Univ., Raleigh, NC (United States); Aller, R.C. [State Univ. of New York, Stony Brook, NY (United States)] [State Univ. of New York, Stony Brook, NY (United States)

1995-09-01

325

Sulfonates: novel electron acceptors in anaerobic respiration  

Microsoft Academic Search

The enrichment and isolation in pure culture of a bacterium, identified as a strain of Desulfovibrio, able to release and reduce the sulfur of isethionate (2-hydroxyethanesulfonate) and other sulfonates to support anaerobic\\u000a respiratory growth, is described. The sulfonate moiety was the source of sulfur that served as the terminal electron acceptor,\\u000a while the carbon skeleton of isethionate functioned as an

Thomas J. Lie; Thomas Pitta; E. R. Leadbetter; Jared R. Leadbetter

1996-01-01

326

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry: a new possibility for the identification and typing of anaerobic bacteria.  

PubMed

Anaerobic bacteria predominate in the normal flora of humans and are important, often life-threatening pathogens in mixed infections originating from the indigenous microbiota. The isolation and identification of anaerobes by phenotypic and DNA-based molecular methods at a species level is time-consuming and laborious. Following the successful adaptation of the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for the routine laboratory identification of bacteria, the extensive development of a database has been initiated to use this method for the identification of anaerobic bacteria. Not only frequently isolated anaerobic species, but also newly recognized and taxonomically rearranged genera and species can be identified using direct smear samples or whole-cell protein extraction, and even phylogenetically closely related species can be identified correctly by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Typing of anaerobic bacteria on a subspecies level, determination of antibiotic resistance and direct identification of blood culture isolates will revolutionize anaerobe bacteriology in the near future. PMID:24571074

Nagy, Elizabeth

2014-02-01

327

Physical properties and biological/odontogenic effects of an experimentally developed fast-setting ?-tricalcium phosphate-based pulp capping material  

PubMed Central

Background Recently, fast-setting ?-tricalcium-phosphate (TCP) cement was developed for use in the pulp capping process. The aim of this study was to investigate the physical properties and biological effects of ?-TCP cement in comparison with mineral trioxide aggregate (MTA). Methods We measured the setting time, pH values, compressive strength, and solubility of the two materials. We evaluated biocompatibility on the basis of cell morphology and a viability test using human dental pulp cells (hDPCs). Chemical composition of each material was analyzed by energy dispersive x-ray spectroscopic (EDS) analysis. The expression of odontogenic-related genes was evaluated by Western blotting and immunofluorescence. The calcified nodule formation was measured by Alizarin red staining. We performed the pulp capping procedure on rat teeth for histological investigation. The data were analyzed by an independent t-test for physical properties, one-way ANOVA for biological effects, and the Mann-Whitney U test for tertiary dentin formation. A P value of less than 0.05 was considered statistically significant for all tests. Results The setting time, pH values, and compressive strength of ?-TCP was lower than that of MTA (P??0.05). Scanning electron microscopy (SEM) revealed that cells attached to both materials were flat and had cytoplasmic extensions. The expression of odontogenic-related markers and mineralized nodule formation were higher in the two experimental groups compared to the control group (P?odontogenicity comparable to MTA, whereas it had a quicker setting time. PMID:25015173

2014-01-01

328

Prevalence of nim genes in anaerobic/facultative anaerobic bacteria isolated in South Africa.  

PubMed

This study investigated the prevalence of nim genes (proposed to encode a 5-nitroimidazole resistance product) in 64 anaerobic/facultative anaerobic bacteria. Employing universal nim gene primers, 458-bp amplified fragments were recorded as presumptive positives in 22/64 strains at an annealing temperature of 52 degrees C and 15/64 strains at 62 degrees C, of which seven were propionibacteria. DNA sequencing confirmed the presence of nimA genes in Propionibacterium spp. (five strains), Actinomyces odontolyticus (one strain), Prevotella bivia (one strain) and Clostridium bifermentans (one strain) and nimB genes from five strains of Bacteroides fragilis. nimA genes were predominant in propionibacteria indicating a potential nimA gene source in anaerobic environments. PMID:10079531

Lubbe, M M; Stanley, K; Chalkley, L J

1999-03-01

329

Surveillance and trends of antimicrobial resistance among clinical isolates of anaerobes in Kuwait hospitals from 2002 to 2007.  

PubMed

The susceptibility trends for all anaerobes processed by the Anaerobe Reference Laboratory against various antibiotics were determined by using data for 2557 isolates referred by all government hospitals in Kuwait from 2002 to 2007. MIC were determined for the following anti-anaerobic antibiotics: amoxicillin-clavulanic acid, clindamycin, imipenem, meropenem, metronidazole, penicillin, piperacillin, piperacillin-tazobactam and vancomycin (for Gram-positive anaerobes only), using E-test method. The commonest isolates were Bacteroides fragilis (36.8%), followed by Peptostreptococcus spp. (21.9%), Bacteroides ovatus (15.5%) and Prevotella bivia (12.1%). In addition, Prevotella oralis and other Bacteroides spp. represented 8.5% and 8.1% of total number of isolates, respectively. Resistance rate varied among the antimicrobial agents and the species tested. The beta-lactams, with the exception of penicillin, were the most active drugs. Piperacillin-tazobactam was the only antimicrobial agent to which all the isolates were uniformly susceptible. Imipenem and metronidazole were highly active with resistance rate of only <5% recorded against most isolates. However, 42.8, 55.8 and 9.3% of Clostridium difficile isolates were resistant to imipenem, clindamycin and meropenem, respectively. It is noteworthy that from 2002 to 2007, there was a gradual increase in resistance rates to clindamycin, amoxicillin-clavulanic acid and piperacillin among B. fragilis. Periodic surveillance of antibiotic resistance among the anaerobic bacteria is recommended as a guide to empiric antibiotic use and formulation of guideline for appropriate choice of antimicrobial therapy in anaerobic infections. PMID:19406247

Jamal, W; Shahin, M; Rotimi, V O

2010-02-01

330

Effect of radiation dose on the recovery of aerobic and anaerobic bacteria from mice  

SciTech Connect

The presence of aerobic and anaerobic bacteria in the blood, spleen, and liver was investigated in mice that were exposed to 7, 8, 9, or 10 Gy /sup 60/Co radiation. Microorganisms were detected more often in animals exposed to higher doses of radiation. The number of mice that were culture positive and the number of isolates in one site increased with increasing dose. Bacteria were recovered in mice killed at various times after radiation, in 3 of 100 mice exposed to 7 Gy, in 13 of 100 irradiated with 8 Gy, in 23 of 90 exposed to 9 Gy, and in 34 of 87 irradiated with 10 Gy. The predominant organisms recovered were Escherichia coli, anerobic Gram-positive cocci, Proteus mirabilis, Staphylococcus aureus, and Bacteroides spp. Escherichia coli and anaerobes were more often isolated in animals exposed to 10 Gy, while S. aureus was more often recovered in those irradiated with 9 Gy. These data demonstrate a relationship between the dose of radiation and the rate of infection due to entire aerobic and anaerobic bacteria. Reprints.

Brook, I.; Walker, R.I.; MacVittie, T.J.

1986-01-01

331

Global Perspective of Anaerobic Treatment of Industrial Wastewater  

Microsoft Academic Search

\\u000a While anaerobic process had been widely used for stabilizing concentrated solids, the process long suffered a poor reputation\\u000a because of lack of understanding regarding its fundamentals. Nearly a century later, anaerobic treatment is now arguably the\\u000a most promising and favorable wastewater treatment system for meeting the desired criteria for future technology in environmentally\\u000a sustainable development. The development of anaerobic processes,

Kuan Yeow Show; Joo Hwa Tay; Yung-Tse Hung

332

Catalase (KatA) Plays a Role in Protection against Anaerobic Nitric Oxide in Pseudomonas aeruginosa  

PubMed Central

Pseudomonas aeruginosa (PA) is a common bacterial pathogen, responsible for a high incidence of nosocomial and respiratory infections. KatA is the major catalase of PA that detoxifies hydrogen peroxide (H2O2), a reactive oxygen intermediate generated during aerobic respiration. Paradoxically, PA displays elevated KatA activity under anaerobic growth conditions where the substrate of KatA, H2O2, is not produced. The aim of the present study is to elucidate the mechanism underlying this phenomenon and define the role of KatA in PA during anaerobiosis using genetic, biochemical and biophysical approaches. We demonstrated that anaerobic wild-type PAO1 cells yielded higher levels of katA transcription and expression than aerobic cells, whereas a nitrite reductase mutant ?nirS produced ?50% the KatA activity of PAO1, suggesting that a basal NO level was required for the increased KatA activity. We also found that transcription of the katA gene was controlled, in part, by the master anaerobic regulator, ANR. A ?katA mutant and a mucoid mucA22 ?katA bacteria demonstrated increased sensitivity to acidified nitrite (an NO generator) in anaerobic planktonic and biofilm cultures. EPR spectra of anaerobic bacteria showed that levels of dinitrosyl iron complexes (DNIC), indicators of NO stress, were increased significantly in the ?katA mutant, and dramatically in a ?norCB mutant compared to basal levels of DNIC in PAO1 and ?nirS mutant. Expression of KatA dramatically reduced the DNIC levels in ?norCB mutant. We further revealed direct NO-KatA interactions in vitro using EPR, optical spectroscopy and X-ray crystallography. KatA has a 5-coordinate high spin ferric heme that binds NO without prior reduction of the heme iron (Kd ?6 ?M). Collectively, we conclude that KatA is expressed to protect PA against NO generated during anaerobic respiration. We proposed that such protective effects of KatA may involve buffering of free NO when potentially toxic concentrations of NO are approached. PMID:24663218

Su, Shengchang; Panmanee, Warunya; Wilson, Jeffrey J.; Mahtani, Harry K.; Li, Qian; VanderWielen, Bradley D.; Makris, Thomas M.; Rogers, Melanie; McDaniel, Cameron; Lipscomb, John D.; Irvin, Randall T.; Schurr, Michael J.; Lancaster, Jack R.; Kovall, Rhett A.; Hassett, Daniel J.

2014-01-01

333

Catalase (KatA) plays a role in protection against anaerobic nitric oxide in Pseudomonas aeruginosa.  

PubMed

Pseudomonas aeruginosa (PA) is a common bacterial pathogen, responsible for a high incidence of nosocomial and respiratory infections. KatA is the major catalase of PA that detoxifies hydrogen peroxide (H2O2), a reactive oxygen intermediate generated during aerobic respiration. Paradoxically, PA displays elevated KatA activity under anaerobic growth conditions where the substrate of KatA, H2O2, is not produced. The aim of the present study is to elucidate the mechanism underlying this phenomenon and define the role of KatA in PA during anaerobiosis using genetic, biochemical and biophysical approaches. We demonstrated that anaerobic wild-type PAO1 cells yielded higher levels of katA transcription and expression than aerobic cells, whereas a nitrite reductase mutant ?nirS produced ?50% the KatA activity of PAO1, suggesting that a basal NO level was required for the increased KatA activity. We also found that transcription of the katA gene was controlled, in part, by the master anaerobic regulator, ANR. A ?katA mutant and a mucoid mucA22 ?katA bacteria demonstrated increased sensitivity to acidified nitrite (an NO generator) in anaerobic planktonic and biofilm cultures. EPR spectra of anaerobic bacteria showed that levels of dinitrosyl iron complexes (DNIC), indicators of NO stress, were increased significantly in the ?katA mutant, and dramatically in a ?norCB mutant compared to basal levels of DNIC in PAO1 and ?nirS mutant. Expression of KatA dramatically reduced the DNIC levels in ?norCB mutant. We further revealed direct NO-KatA interactions in vitro using EPR, optical spectroscopy and X-ray crystallography. KatA has a 5-coordinate high spin ferric heme that binds NO without prior reduction of the heme iron (Kd ?6 ?M). Collectively, we conclude that KatA is expressed to protect PA against NO generated during anaerobic respiration. We proposed that such protective effects of KatA may involve buffering of free NO when potentially toxic concentrations of NO are approached. PMID:24663218

Su, Shengchang; Panmanee, Warunya; Wilson, Jeffrey J; Mahtani, Harry K; Li, Qian; Vanderwielen, Bradley D; Makris, Thomas M; Rogers, Melanie; McDaniel, Cameron; Lipscomb, John D; Irvin, Randall T; Schurr, Michael J; Lancaster, Jack R; Kovall, Rhett A; Hassett, Daniel J

2014-01-01

334

Anaerobic Metabolism and Bioremediation of Explosives-Contaminated Soil  

NASA Astrophysics Data System (ADS)

Nitroaromatic compounds pollute soil, water, and food via use of pesticides, plastics, pharmaceuticals, landfill dumping of industrial wastes, and the military use of explosives. Biotransformation of trinitrotoluene and other nitroaromatics by aerobic bacteria in the laboratory has been frequently reported, but the anaerobic bacterial metabolism of nitroaromatics has not been studied as extensively perhaps due to the difficulty in working with anaerobic cultures and the slow growth of anaerobes. Sulfate-reducing and methanogenic bacteria can metabolize nitroaromatic compounds under anaerobic conditions if appropriate electron donors and electron acceptors are present in the environment.

Boopathy, Raj

335

Whipworm infection  

MedlinePLUS

... of the large intestine with a type of roundworm. ... Whipworm infection is caused by the roundworm, Trichuris trichiura. It is a common infection that mainly affects children. Children may become infected if they swallow soil contaminated with whipworm ...

336

Clostridium difficile infection: A critical overview  

Microsoft Academic Search

Clostridium difficile is a gram-positive, spore-forming, toxin-producing anaerobic bacillus identified as the causal agent of a variety of manifestations\\u000a typically isolated to the colon, but in its severe form, it can lead to sepsis and death. C. difficile infection due to a toxin gene variant strain (BI\\/NAP1) has been identified at the center of outbreaks and has resulted in\\u000a increased

Bayan Missaghi; August J. Valenti; Robert C. Owens Jr

2008-01-01

337

Clostridium difficile Infection: A Worldwide Disease  

PubMed Central

Clostridium difficile, an anaerobic toxigenic bacterium, causes a severe infectious colitis that leads to significant morbidity and mortality worldwide. Both enhanced bacterial toxins and diminished host immune response contribute to symptomatic disease. C. difficile has been a well-established pathogen in North America and Europe for decades, but is just emerging in Asia. This article reviews the epidemiology, microbiology, pathophysiology, and clinical management of C. difficile. Prompt recognition of C. difficile is necessary to implement appropriate infection control practices. PMID:24516694

Burke, Kristin E.

2014-01-01

338

Biofilms in pediatric respiratory and related infections  

Microsoft Academic Search

Bacteria can grow as free-floating, planktonic bacteria or complex communities called biofilms. Biofilms promote bacterial\\u000a growth and diversity and offer bacteria unique environments, including aerobic and anaerobic layers, that facilitate resistance\\u000a to antimicrobial therapies. Respiratory and related structures provide ideal environments for the development of bacterial\\u000a biofilms, which predispose patients to recurrent and chronic infections. Biofilms are important for the

Yi-Chun Carol Liu; J. Christopher Post

2009-01-01

339

Culturable Aerobic and Facultative Anaerobic Intestinal Bacterial Flora of Black Cobra (Naja naja karachiensis) in Southern Pakistan  

PubMed Central

Using morphological analysis and biochemical testing, here for the first time, we determined the culturable gut bacterial flora (aerobes and facultative anaerobes) in the venomous Black Cobra (Naja naja karachiensis) from South Asia. The findings revealed that these snakes inhabit potentially pathogenic bacteria including Serratia marcescens, Pseudomonas aeruginosa, Shewanella putrefaciens, Aeromonas hydrophila, Salmonella sp., Moraxella sp., Bacillus sp., Ochrobactrum anthropi, and Providencia rettgeri. These findings are of concern, as injury from snake bite can result in wound infections and tissue necrosis leading to sepsis/necrotizing fasciitis and/or expose consumers of snake meat/medicine in the community to infections. PMID:25002979

Iqbal, Junaid; Sagheer, Mehwish; Tabassum, Nazneen; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

2014-01-01

340

40 CFR Table Jj-6 to Subpart Jj of... - Collection Efficiencies of Anaerobic Digesters  

...Efficiencies of Anaerobic Digesters Anaerobic digester type Cover type Methane collection efficiency Covered anaerobic lagoon (biogas capture) Bank to bank, impermeable 0.975 Modular, impermeable 0.70 Complete mix, fixed film, or plug...

2014-07-01

341

40 CFR Table Jj-6 to Subpart Jj of... - Collection Efficiencies of Anaerobic Digesters  

Code of Federal Regulations, 2013 CFR

...Efficiencies of Anaerobic Digesters Anaerobic digester type Cover type Methane collection efficiency Covered anaerobic lagoon (biogas capture) Bank to bank, impermeable 0.975 Modular, impermeable 0.70 Complete mix, fixed film, or plug...

2013-07-01

342

Stimulation of Organic Contaminant Biodegradation Through The Amendment of Anaerobic Electron Acceptors To Estuarine Sediments  

E-print Network

was undertaken to test the feasibility of anaerobic electron acceptor (AEA) amendment to stimulate the in situ changes in sediment terminal electron accepting processes and increasing anaerobic biodegradationStimulation of Organic Contaminant Biodegradation Through The Amendment of Anaerobic Electron

Rockne, Karl J.

343

Integrated Genotypic Analysis of Hedgehog-Related Genes Identifies Subgroups of Keratocystic Odontogenic Tumor with Distinct Clinicopathological Features  

PubMed Central

Keratocystic odontogenic tumor (KCOT) arises as part of Gorlin syndrome (GS) or as a sporadic lesion. Gene mutations and loss of heterozygosity (LOH) of the hedgehog receptor PTCH1 plays an essential role in the pathogenesis of KCOT. However, some KCOT cases lack evidence for gene alteration of PTCH1, suggesting that other genes in the hedgehog pathway may be affected. PTCH2 and SUFU participate in the occurrence of GS-associated tumors, but their roles in KCOT development are unknown. To elucidate the roles of these genes, we enrolled 36 KCOT patients in a study to sequence their entire coding regions of PTCH1, PTCH2 and SUFU. LOH and immunohistochemical expression of these genes, as well as the downstream targets of hedgehog signaling, were examined using surgically-excised KCOT tissues. PTCH1 mutations, including four novel ones, were found in 9 hereditary KCOT patients, but not in sporadic KCOT patients. A pathogenic mutation of PTCH2 or SUFU was not found in any patients. LOH at PTCH1 and SUFU loci correlated with the presence of epithelial budding. KCOT harboring a germline mutation (Type 1) showed nuclear localization of GLI2 and frequent histological findings such as budding and epithelial islands, as well as the highest recurrence rate. KCOT with LOH but without a germline mutation (Type 2) less frequently showed these histological features, and the recurrence rate was lower. KCOT with neither germline mutation nor LOH (Type 3) consisted of two subgroups, Type 3A and 3B, which were characterized by nuclear and cytoplasmic GLI2 localization, respectively. Type 3B rarely exhibited budding and recurrence, behaving as the most amicable entity. The expression patterns of CCND1 and BCL2 tended to correlate with these subgroups. Our data indicates a significant role of PTCH1 and SUFU in the pathogenesis of KCOT, and the genotype-oriented subgroups constitute entities with different potential aggressiveness. PMID:23951062

Shimada, Yasuyuki; Katsube, Ken-ichi; Kabasawa, Yuji; Morita, Kei-ichi; Omura, Ken; Yamaguchi, Akira; Sakamoto, Kei

2013-01-01

344

Human serum activity of telithromycin, azithromycin and amoxicillin/clavulanate against common aerobic and anaerobic respiratory pathogens.  

PubMed

Telithromycin is a new ketolide antimicrobial with a good in vitro activity against both aerobic and anaerobic respiratory pathogens. In this study, we evaluated the antibacterial activity over time of telithromycin (800mg), azithromycin (500mg), and amoxicillin/clavulanate (875/125mg) in serum following single oral doses of these agents to 10 healthy subjects. Inhibitory and bactericidal titers were determined at 2, 6, 12, and 24h after each dose and the median titer was used to determine antibacterial activity. Against two azithromycin-resistant strains of Streptococcus pneumoniae, both telithromycin (MIC=0.25 and 0.5 microg/mL) and amoxicillin/clavulanate exhibited inhibitory and cidal activity for at least 6h. All three antibiotics provided prolonged (>or=12h) inhibitory activity against strains of Hemophilus influenzae (telithromycin MIC=4.0 microg/ml). Both telithromycin and amoxicillin/clavulanate exhibited rapid and prolonged inhibitory activity (>or=12h) against each of the anaerobes studied (Finegoldia [Peptostreptococcus] magna Peptostreptococcus micros, Prevotella bivia, and Prevotella melaninogenica). Moreover, both agents provided bactericidal activity against both Prevotella species. In this ex vivo pharmacodynamic study, we found that telithromycin provided rapid and prolonged antibacterial activity in serum against macrolide-resistant strains of S. pneumoniae, beta-lactamase-positive and -negative strains of H. influenzae, and common respiratory anaerobic pathogens. These findings suggest that telithromycin could have clinical utility in the treatment of community-acquired mixed aerobic-anaerobic respiratory tract infections, including chronic sinusitis and aspiration pneumonia. PMID:17189093

Stein, Gary E; Schooley, Sharon; Tyrrell, Kerin L; Citron, Diane M; Goldstein, Ellie J C

2007-01-01

345

Improving thermophilic anaerobic digestion of swine manure  

Microsoft Academic Search

Thermophilic (55°C) anaerobic degradation of swine manure was found possible even at an ammonia content of 6g-N\\/l, with a low methane yield of only 67ml CH4\\/g-VS and a high concentration of volatile fatty acids (11.5g acetate\\/l). Several methods were tested in order to increase the methane yield. Addition of 1.5% (w\\/w) activated carbon, 10% (w\\/w) glauconite or 1.5% (w\\/w) activated

Kaare Hvid Hansen; Irini Angelidaki; Birgitte KiÆr Ahring

1999-01-01

346

Reduction of azo dyes by intestinal anaerobes.  

PubMed Central

Reduction of seven azo dyes (amaranth, Ponceau SX, Allura Red, Sunset Yellow, tartrazine, Orange II, and methyl orange) was carried out by cell suspensions of predominant intestinal anaerobes. It was optimal at pH 7.4 in 0.4 M phosphate buffer and inhibited by glucose. Flavin mononucleotide caused a marked enhancement of azo reduction by Bacteroides thetaiotaomicron. Other electron carriers, e.g., methyl viologen, benzyl viologen, phenosafranin, neutral red, crystal violet, flavin adenine dinucleotide, menadione, and Janus Green B can replace flavin mononucleotide. These data suggest that an extracellular shuttle is required for azo reduction. PMID:25047

Chung, K T; Fulk, G E; Egan, M

1978-01-01

347

Management of human and animal bite wound infection: An overview  

Microsoft Academic Search

Animal and human bite wounds can lead to serious infections. The organisms recovered generally originate from the biter’s\\u000a oral cavity and the victim’s skin flora. Anaerobes were isolated from more than two thirds of human and animal bite infections.\\u000a Streptococcus pyogenes is often recovered in human bites, Pasteurella multocida in animal bites, Eikenella corrodens in animal and human, Capnocytophaga spp,

Itzhak Brook

2009-01-01

348

In storage psychrophilic anaerobic digestion of swine slurry  

Microsoft Academic Search

Anaerobic digestion of manures induces deodorization and conserves nitrogen. Livestock producers could transform their long-term (250–300 day) manure storages into psychrophilic anaerobic digesters, thus greatly reducing the investment, operational and technical cost associated with the treatment. But, sufficient inoculation is required and the feeding regime differs from that of a fixed volume digester, as the fed manure volume to digester

J. Abou Nohra; S. Barrington; J. C. Frigon; S. R. Guiot

2003-01-01

349

Metabolism of alkylbenzenes, alkanes, and other hydrocarbons in anaerobic bacteria  

Microsoft Academic Search

Aromatic and aliphatic hydrocarbons are the main constituents of petroleum and its refined products. Whereas degradation of hydrocarbons by oxygen-respiring microorganisms has been known for about a century, utilization of hydrocarbons under anoxic conditions has been investigated only during the past decade. Diverse strains of anaerobic bacteria have been isolated that degrade toluene anaerobically, using nitrate, iron(III), or sulfate as

Alfred M. Spormann; Friedrich Widdel

2000-01-01

350

Identification of Anaerobic Selenate-Respiring Bacteria from Aquatic Sediments  

Microsoft Academic Search

The diversity population of microorganisms with the capability to use selenate as a terminal electron acceptor, reducing it to selenite and elemental selenium by the process known as dissimilatory selenate reduction, is largely unknown. The overall objective of this study was to gain an in-depth understanding of anaerobic biotransformation of selenium in the environment, particularly anaerobic respiration, and to characterize

Priya Narasingarao; Max M. Haggblom

2007-01-01

351

LOVES CREEK ANAEROBIC, UPFLOW (ANFLOW) PILOT PLANT: PERFORMANCE SUMMARY  

EPA Science Inventory

Anaerobic filter technology for municipal wastewater treatment has been studied in Knoxville, Tennessee with a 190-m exp 3 /d facility from August 1981 to October 1983. The ORNL project (described by the acronym ANFLOW for the anaerobic, upflow characteristics of the technology) ...

352

Doctoral Defense "Low-Temperature Anaerobic Membrane Bioreactor for  

E-print Network

highlighting microbial community shifts in the bioreactor and biofilm during changes in membrane foulingDoctoral Defense "Low-Temperature Anaerobic Membrane Bioreactor for Energy Recovery from Domestic such as anaerobic membrane bioreactors (AnMBRs) are emerging as one option to recover energy during domestic

Kamat, Vineet R.

353

Mediation of sulfur speciation by a Black Sea facultative anaerobe  

Microsoft Academic Search

Shewanella putrefaciens, a respiratory facultative anaerobe isolated from the Black Sea, can reduce thiosulfate, sulfite, and elemental sulfur to sulfide readily and quantitatively. This widespread and anaerobically versatile microorganism, which is incapable of reducing sulfate, uses oxidized sulfur intermediates as electron acceptors during the respiratory oxidation of organic matter. Because of its widespread distribution and abundance, it may play a

K. A. Perry; J. E. Kostka; G. W. Luther; K. H. Nealson

1993-01-01

354

Anaerobic Methane Oxidation in a Landfill-Leachate Plume  

E-print Network

Anaerobic Methane Oxidation in a Landfill-Leachate Plume E T H A N L . G R O S S M A N , * , L U I of leachate contamination into underlying aquifers. Landfills are the U.S.'s largest anthropogenic sourceNormanLandfillinOklahomaprovidesanexcellentnatural laboratory for the study of anaerobic methane oxidation in landfill-leachate plumes. Several comprehensive

Grossman, Ethan L.

355

Enhanced dechlorination of aroclor 1242 in an anaerobic continuous bioreactor  

Microsoft Academic Search

Disappearance of Aroclor 1242 was observed in a continuously operated upflow anaerobic sludge bed (UASB) reactor inoculated with granular anaerobic sludge. To distinguish between sorption and dechlorination processes, extraction of Aroclor from the sludge was performed along with the measurements of chloride and Aroclor in the reactor effluent. A release of inorganic chloride combined with the enrichment in lightly chlorinated

B Tartakovsky; J Hawari; S. R Guiot

2000-01-01

356

Evaluation of Fastidious Anaerobe Broth as a blood culture medium  

Microsoft Academic Search

Three commercial blood culture media were compared with a freshly prepared cooked meat medium in tests to stimulate the recovery of small inocula of anaerobic and aerobic bacteria in routine blood cultures. The cooked meat medium gave the most reliable recovery and supported continued viability, whilst Fastidious Anaerobe Broth (LAB M) was a good alternative. Results with Southern Group thioglycollate

L A Ganguli; L J Turton; G S Tillotson

1982-01-01

357

Recent developments in hydrogen management during anaerobic biological wastewater treatment  

Microsoft Academic Search

A comprehensive review of the microbial kinetics, energetics, and substrate specificities of anaerobic wastewater treatment systems is presented with descriptions of three different state-of-the-art reactor configurations. Each of these reactor systems is intended to enrich different populations of anaerobic acidogens and methanogens as a result of design and operational strategies for control of hydrogen and volatile acids. Imposition of these

Stephen R. Harper; Frederick G. Pohland

1986-01-01

358

Modeling for anaerobic fixed-bed biofilm reactors  

Microsoft Academic Search

Biofilm models, developed by previous researchers, were incorporated with an equilibrium model to study the physical and chemical aspects of the anaerobic fixed-bed biofilm reactors. In order to investigate the mechanism of equilibrium in an anaerobic biofilm reactor, a non-equilibrium model was derived from the equilibrium model to simulate the gas transfer process involved in biogas production. The equilibrium model

Yeongming Bill

1989-01-01

359

Solids removal in upflow anaerobic reactors, a review  

Microsoft Academic Search

This desk study deals with the mechanisms and parameters affecting particles separation from wastewater in mainly upflow anaerobic reactors. Despite the fact that the functioning of upflow anaerobic sludge blanket (UASB) systems depends on both physical parameters and biological processes, the physical parameters have been barely reported in the literature. The reason is that the underlying mechanisms are very complex

Nidal Mahmoud; Grietje Zeeman; Huub Gijzen; Gatze Lettinga

2003-01-01

360

Importance of the methanogenic archaea populations in anaerobic wastewater treatments  

Microsoft Academic Search

Methane derived from anaerobic treatment of organic wastes has a great potential to be an alternative fuel. Abundant biomass from various industries could be a source for biomethane production where combination of waste treatment and energy production would be an advantage. This article summarizes the importance of the microbial population, with a focus on the methanogenic archaea, on the anaerobic

Meisam Tabatabaei; Raha Abdul Rahim; Norhani Abdullah; André-Denis G. Wright; Yoshihito Shirai; Kenji Sakai; Alawi Sulaiman; Mohd Ali Hassan

2010-01-01

361

Equipment used for testing anaerobic biodegradability and activity  

Microsoft Academic Search

Recently there has been a growing demand for information on the biodegradability and microbial toxicity of xenobiotic compounds. The environmental fate and effect of these chemicals in aerobic and anaerobic conditions has been extensively studied using a variety of different methods. This paper reviews the different protocols, equipment and instruments used in anaerobic biodegradation and activity tests, including the more

A. J. Guwy

2004-01-01

362

Anaerobic treatment of effluents from an industrial polymers synthesis plant  

Microsoft Academic Search

The feasibility of the anaerobic treatment of an industrial polymer synthesis plant effluent was evaluated. The composition of the wastewater includes acrylates, styrene, detergents, a minor amount of silicates and a significant amount of ferric chloride. The average chemical oxygen demand (COD) corresponding is about 2000mg\\/l. The anaerobic biodegradability of the effluent is shown and the toxicity effect on the

P. Araya; G. Aroca; R. Chamy

1999-01-01

363

TEST RESULTS FOR FUEL CELL OPERATION ON ANAEROBIC DIGESTER GAS  

EPA Science Inventory

EPA, in conjunction with ONSI Corp., embarked on a project to define, design, test, and assess a fuel cell energy recovery system for application at anaerobic digester waste water (sewage) treatment plants. Anaerobic digester gas (ADG) is produced at these plants during the proce...

364

Response of anaerobic ammonium-oxidizing bacteria to hydroxylamine  

Microsoft Academic Search

Anaerobic ammonium oxidation is a recent addition to the microbial nitrogen cycle, and its metabolic pathway, including the production and conversion of its intermediate hydrazine, is not well understood. Therefore, the effect of hydroxylamine addition on the hydrazine metabolism of anaerobic ammonium-oxidizing (anammox) bacteria was studied both experimentally and by mathematical modeling. It was observed that hydroxylamine was disproportionated biologically

Maarten J. Van De Graaf; Boran Kartal; Cristian Picioreanu; Mike S. M. Jetten

2008-01-01

365

A marine microbial consortium apparently mediating anaerobic oxidation of methane  

Microsoft Academic Search

A large fraction of globally produced methane is converted to CO2 by anaerobic oxidation in marine sediments. Strong geochemical evidence for net methane consumption in anoxic sediments is based on methane profiles, radiotracer experiments and stable carbon isotope data. But the elusive microorganisms mediating this reaction have not yet been isolated, and the pathway of anaerobic oxidation of methane is

Antje Boetius; Katrin Ravenschlag; Carsten J. Schubert; Dirk Rickert; Friedrich Widdel; Armin Gieseke; Rudolf Amann; Bo Barker Jørgensen; Ursula Witte; Olaf Pfannkuche

2000-01-01

366

Comparison of techniques for isolation and identification of anaerobic bacteria\\  

Microsoft Academic Search

In this symposium a variety of systems for cultivation of anaerobic bacteria have been described and the advantages of some of the recently described culture techniques have been clearly shown. However, there is litfie published information on comparison of these systems, and it is difficult for microbi- ologists with limited experience in anaerobic bacteriology to choose which system(s) are most

V. R. Dowel

367

Balancing hygienization and anaerobic digestion of raw sewage sludge.  

PubMed

The anaerobic digestion of raw sewage sludge was evaluated in terms of process efficiency and sludge hygienization. Four different scenarios were analyzed, i.e. mesophilic anaerobic digestion, thermophilic anaerobic digestion and mesophilic anaerobic digestion followed by a 60 °C or by an 80 °C hygienization treatment. Digester performance (organic matter removal, process stability and biogas yield) and the hygienization efficiency (reduction of Escherichia coli, somatic coliphages and F-specific RNA phages) were the main examined factors. Moreover, a preliminary economical feasibility study of each option was carried out throughout an energy balance (heat and electricity). The obtained results showed that both thermophilic anaerobic digestion and mesophilic anaerobic digestion followed by a hygienization step were able to produce an effluent sludge that fulfills the American and the European legislation for land application. However, higher removal efficiencies of indicators were obtained when a hygienization post-treatment was present. Regarding the energy balance, it should be noted that all scenarios have a significant energy surplus. Particularly, positive heat balances will be obtained for the thermophilic anaerobic digestion and for the mesophilic anaerobic digestion followed by 60 °C hygienization post-treatment if an additional fresh-sludge/digested sludge heat exchanger is installed for energy recovery. PMID:23063441

Astals, S; Venegas, C; Peces, M; Jofre, J; Lucena, F; Mata-Alvarez, J

2012-12-01

368

Anaerobic Threshold and Salivary ?-amylase during Incremental Exercise  

PubMed Central

[Purpose] The purpose of this study was to clarify the validity of salivary ?-amylase as a method of quickly estimating anaerobic threshold and to establish the relationship between salivary ?-amylase and double-product breakpoint in order to create a way to adjust exercise intensity to a safe and effective range. [Subjects and Methods] Eleven healthy young adults performed an incremental exercise test using a cycle ergometer. During the incremental exercise test, oxygen consumption, carbon dioxide production, and ventilatory equivalent were measured using a breath-by-breath gas analyzer. Systolic blood pressure and heart rate were measured to calculate the double product, from which double-product breakpoint was determined. Salivary ?-amylase was measured to calculate the salivary threshold. [Results] One-way ANOVA revealed no significant differences among workloads at the anaerobic threshold, double-product breakpoint, and salivary threshold. Significant correlations were found between anaerobic threshold and salivary threshold and between anaerobic threshold and double-product breakpoint. [Conclusion] As a method for estimating anaerobic threshold, salivary threshold was as good as or better than determination of double-product breakpoint because the correlation between anaerobic threshold and salivary threshold was higher than the correlation between anaerobic threshold and double-product breakpoint. Therefore, salivary threshold is a useful index of anaerobic threshold during an incremental workload. PMID:25140097

Akizuki, Kazunori; Yazaki, Syouichirou; Echizenya, Yuki; Ohashi, Yukari

2014-01-01

369

Anaerobes and bacterial vaginosis in pregnancy: virulence factors contributing to vaginal colonisation.  

PubMed

The aetiology and pathogenesis of bacterial vaginosis (BV) is unclear but it appears to be associated with factors that disrupt the normal acidity of the vagina thus altering the equilibrium between the normal vaginal microbiota. BV has serious implications for female morbidity, including reports of pelvic inflammatory disease, adverse pregnancy outcomes, increased susceptibility to sexually transmitted infections and infertility. This paper reviewed new available information regarding possible factors contributing to the establishment of the BV vaginal biofilm, examined the proposed role of anaerobic microbial species recently detected by new culture-independent methods and discusses developments related to the effects of BV on human pregnancy. The literature search included Pubmed (NLM), LISTA (EBSCO), and Web of Science. Because of the complexity and diversity of population groups, diagnosis and methodology used, no meta-analysis was performed. Several anaerobic microbial species previously missed in the laboratory diagnosis of BV have been revealed while taking cognisance of newly proposed theories of infection, thereby improving our understanding and knowledge of the complex aetiology and pathogenesis of BV and its perceived role in adverse pregnancy outcomes. PMID:25014248

Africa, Charlene W J; Nel, Janske; Stemmet, Megan

2014-07-01

370

Anaerobes and Bacterial Vaginosis in Pregnancy: Virulence Factors Contributing to Vaginal Colonisation  

PubMed Central

The aetiology and pathogenesis of bacterial vaginosis (BV) is unclear but it appears to be associated with factors that disrupt the normal acidity of the vagina thus altering the equilibrium between the normal vaginal microbiota. BV has serious implications for female morbidity, including reports of pelvic inflammatory disease, adverse pregnancy outcomes, increased susceptibility to sexually transmitted infections and infertility. This paper reviewed new available information regarding possible factors contributing to the establishment of the BV vaginal biofilm, examined the proposed role of anaerobic microbial species recently detected by new culture-independent methods and discusses developments related to the effects of BV on human pregnancy. The literature search included Pubmed (NLM), LISTA (EBSCO), and Web of Science. Because of the complexity and diversity of population groups, diagnosis and methodology used, no meta-analysis was performed. Several anaerobic microbial species previously missed in the laboratory diagnosis of BV have been revealed while taking cognisance of newly proposed theories of infection, thereby improving our understanding and knowledge of the complex aetiology and pathogenesis of BV and its perceived role in adverse pregnancy outcomes. PMID:25014248

Africa, Charlene W. J.; Nel, Janske; Stemmet, Megan

2014-01-01

371

Comparative in-vitro and in-vivo activity of AM-1155 against anaerobic bacteria.  

PubMed

The in-vitro activity of AM-1155, a 6-fluoro-8-methoxy quinolone, was compared with those of temafloxacin, sparfloxacin, tosufloxacin, ciprofloxacin, ofloxacin and cefmetazole, a cephamycin, against a variety of anaerobic bacteria. Although AM-1155 demonstrated only modest activity against the Bacteroides fragilis group and Prevotella bivia (MIC90s > or =3.13 mg/mL), 76% of the B. fragilis strains tested were inhibited at AM-1155 concentrations of 0.78 mg/L. AM-1155 was highly active against Prevotella intermedia, Porphyromonas gingivalis, Fusobacterium spp., Clostridium perfringens and Mobiluncus spp. (MIC90s < or =0.39 mg/L). An in-vivo study using a mixed infection with AM-1155- and tosufloxacin-susceptible B. fragilis and Escherichia coli strains in rat granuloma pouch was performed. AM-1155 was effective against both organisms whereas tosufloxacin was effective only against E. coli. These results correlated well to the higher pouch levels of AM-1155 than those of tosufloxacin. Clostridium difficile overgrowth was found in the caecum of mice treated with ampicillin both 1 and 7 days after 5 days dosing, but not in AM-1155-treated mice. These results suggest that the clinical efficacy of AM-1155 against infections involving most anaerobic bacteria except for the B. fragilis group and P. bivia should be evaluated further. PMID:9421310

Kato, N; Kato, H; Tanaka-Bandoh, K; Watanabe, K; Ueno, K

1997-11-01

372

Influence of cyanide on the anaerobic degradation of glucose.  

PubMed

Bacteria in the anaerobic degradation process convert the substrate to the final products methane and carbon dioxide. Toxic substances can change the process substantially. The purpose of this study was to investigate the influence of toxic cyanide on biogas production in anaerobic degradation of glucose at 40°C. The OxiTop respirometric system offers a quick and simple method for measurement of the biogas formed. Concentrations of cyanide (CN(-)) added to 640?mg?COD/L of glucose varied from 0.325 up to 31.000?mg/L. The inhibition of anaerobic degradation of glucose was evaluated from the lag phase, the coefficient of anaerobic degradation (D(h)), the volume and composition of the biogas and degradation of COD in the liquid phase. If the concentration of cyanide was above 2.600?mg/L inhibition of the anaerobic process was substantial. PMID:20962395

Pirc, E Tratar; Levstek, Meta; Bukovec, Peter

2010-01-01

373

Anaerobic and aerobic transformation of TNT  

SciTech Connect

Most studies on the microbial metabolism of nitroaromatic compounds have used pure cultures of aerobic microorganisms. In many cases, attempts to degrade nitroaromatics under aerobic conditions by pure cultures result in no mineralization and only superficial modifications of the structure. However, mixed culture systems properly operated result in the transformation of 2,4,6-trinitrotoluene (TNT) and in some cases mineralization of TNT occurs. In this paper, the mixed culture system is described with emphasis on intermediates and the characteristics of the aerobic microbial process including the necessity for a co-substrate. The possibility of removing TNT under aerobic/anoxic conditions is described in detail. Another option for the biodegradation of TNT and nitroaromatics is under anaerobic, sulfate reducing conditions. In this instance, the nitroaromatic compounds undergo a series of reductions with the formation of amino compounds. TNT under sulfate reducing conditions is reduced to triaminotoluene presumably by the enzyme nitrite reductase, which is commonly found in many Desulfovibrio spp. The removal of nitro groups from TNT is achieved by a series of reductive reactions with the formation of ammonia and toluene by Desulfovibrio sp. (B strain). These metabolic processes could be applied to other nitroaromatic compounds like nitrobenzene, nitrobenzoic acids, nitrophenols, and aniline. The data supporting the anaerobic transformation of TNT under different growth condition are reviewed in this report.

Kulpa, C.F. [Univ. of Notre Dame, IN (United States). Dept. of Biological Sciences; Boopathy, R.; Manning, J. [Argonne National Lab., IL (United States). Environmental Research Div.

1996-12-31

374

The anaerobic digestion of solid organic waste.  

PubMed

The accumulation of solid organic waste is thought to be reaching critical levels in almost all regions of the world. These organic wastes require to be managed in a sustainable way to avoid depletion of natural resources, minimize risk to human health, reduce environmental burdens and maintain an overall balance in the ecosystem. A number of methods are currently applied to the treatment and management of solid organic waste. This review focuses on the process of anaerobic digestion which is considered to be one of the most viable options for recycling the organic fraction of solid waste. This manuscript provides a broad overview of the digestibility and energy production (biogas) yield of a range of substrates and the digester configurations that achieve these yields. The involvement of a diverse array of microorganisms and effects of co-substrates and environmental factors on the efficiency of the process has been comprehensively addressed. The recent literature indicates that anaerobic digestion could be an appealing option for converting raw solid organic wastes into useful products such as biogas and other energy-rich compounds, which may play a critical role in meeting the world's ever-increasing energy requirements in the future. PMID:21530224

Khalid, Azeem; Arshad, Muhammad; Anjum, Muzammil; Mahmood, Tariq; Dawson, Lorna

2011-08-01

375

Tolerance of Anaerobic Bacteria to Chlorinated Solvents  

PubMed Central

The aim of this research was to evaluate the effects of four chlorinated aliphatic hydrocarbons (CAHs), perchloroethene (PCE), carbon tetrachloride (CT), chloroform (CF) and 1,2-dichloroethane (1,2-DCA), on the growth of eight anaerobic bacteria: four fermentative species (Escherichia coli, Klebsiella sp., Clostridium sp. and Paenibacillus sp.) and four respiring species (Pseudomonas aeruginosa, Geobacter sulfurreducens, Shewanella oneidensis and Desulfovibrio vulgaris). Effective concentrations of solvents which inhibited growth rates by 50% (EC50) were determined. The octanol-water partition coefficient or log Po/w of a CAH proved a generally satisfactory measure of its toxicity. Most species tolerated approximately 3-fold and 10-fold higher concentrations of the two relatively more polar CAHs CF and 1,2-DCA, respectively, than the two relatively less polar compounds PCE and CT. EC50 values correlated well with growth rates observed in solvent-free cultures, with fast-growing organisms displaying higher tolerance levels. Overall, fermentative bacteria were more tolerant to CAHs than respiring species, with iron- and sulfate-reducing bacteria in particular appearing highly sensitive to CAHs. These data extend the current understanding of the impact of CAHs on a range of anaerobic bacteria, which will benefit the field of bioremediation. PMID:24441515

Koenig, Joanna C.; Groissmeier, Kathrin D.; Manefield, Mike J.

2014-01-01

376

Treatment of slaughterhouse wastewaters using anaerobic filters.  

PubMed

In this paper, a laboratory-scale experimentation allowed comparing the performances of two upflow anaerobic packed-bed filters filled with different packing materials and operating at mesophilic conditions (30 degreeC) for treating slaughterhouse wastewaters. Methane production was experimentally evaluated considering different volumetric organic loading rates as well as feeding overloading conditions. Although filter performances declined with loading rates higher than 6 kg CODin m-3 d-1 , the chemical oxygen demand (COD) removal efficiency remained always above 60%. The experimental results allowed for determining kinetic parameters for bacterial growth rate and methane production, following Monod and Chen-Hashimoto models, respectively. Results demonstrated that the reactors reached a cellular retention time significantly greater than the hydraulic retention time. The kinetic parameter values (Ks, l/max) revealed the low microorganisms' affinity for the substrate and confirmed the moderate biodegradability of slaughterhouse wastewater. The kinetic analysis also allowed the comparison of the filters performances with another anaerobic system and the assessment of the parameters useful for real-scale plant design. The system design, applied to a medium-sized Argentinean slaughterhouse, demonstrated to (i) be energetically self-sufficient and (ii) contribute to the plant's water heating requirements. PMID:24600871

Martinez, Sandra Luz; Torretta, Vincenzo; Minguelac, Jésus Vázquez; Siñeriz, Faustino; Raboni, Massimo; Copelli, Sabrina; Rada, Elena Cristina; Ragazzi, Marco

2014-01-01

377

Obstetric Infections  

PubMed Central

Maternal infections are unique because of their implications for the outcome of pregnancy. Bacterial infections that can be favorably influenced by prompt diagnosis and preventive management include urinary tract infections and chorioamnionitis. However, viral infections such as genital herpes and cytomegalovirus, and the parasitic disease toxoplasmosis, require specialized forms of testing and a complicated management plan. Altered physiological and immunological states during pregnancy are important in understanding the pathophysiology of maternal infections. PMID:7020253

Oster, Henry A.

1981-01-01

378

Biochemistry and Evolution of Anaerobic Energy Metabolism in Eukaryotes  

PubMed Central

Summary: Major insights into the phylogenetic distribution, biochemistry, and evolutionary significance of organelles involved in ATP synthesis (energy metabolism) in eukaryotes that thrive in anaerobic environments for all or part of their life cycles have accrued in recent years. All known eukaryotic groups possess an organelle of mitochondrial origin, mapping the origin of mitochondria to the eukaryotic common ancestor, and genome sequence data are rapidly accumulating for eukaryotes that possess anaerobic mitochondria, hydrogenosomes, or mitosomes. Here we review the available biochemical data on the enzymes and pathways that eukaryotes use in anaerobic energy metabolism and summarize the metabolic end products that they generate in their anaerobic habitats, focusing on the biochemical roles that their mitochondria play in anaerobic ATP synthesis. We present metabolic maps of compartmentalized energy metabolism for 16 well-studied species. There are currently no enzymes of core anaerobic energy metabolism that are specific to any of the six eukaryotic supergroup lineages; genes present in one supergroup are also found in at least one other supergroup. The gene distribution across lineages thus reflects the presence of anaerobic energy metabolism in the eukaryote common ancestor and differential loss during the specialization of some lineages to oxic niches, just as oxphos capabilities have been differentially lost in specialization to anoxic niches and the parasitic life-style. Some facultative anaerobes have retained both aerobic and anaerobic pathways. Diversified eukaryotic lineages have retained the same enzymes of anaerobic ATP synthesis, in line with geochemical data indicating low environmental oxygen levels while eukaryotes arose and diversified. PMID:22688819

Muller, Miklos; Mentel, Marek; van Hellemond, Jaap J.; Henze, Katrin; Woehle, Christian; Gould, Sven B.; Yu, Re-Young; van der Giezen, Mark

2012-01-01

379

Low temperature pre-treatment of domestic sewage in an anaerobic hybrid or an anaerobic filter reactor  

Microsoft Academic Search

The pre-treatment of domestic sewage for removal of suspended solids (SS) at a process temperature of 13 °C and an hydraulic retention time (HRT) of 4 h was investigated in an anaerobic filter (AF) and anaerobic hybrid (AH) reactor. The AF and the top of the AH reactor consisted of vertical sheets of reticulated polyurethane foam (RPF) with knobs. All

Tarek A Elmitwalli; Vladimir Sklyar; Grietje Zeeman; Gatze Lettinga

2002-01-01

380

Treatment of domestic sewage in a two-step anaerobic filter\\/anaerobic hybrid system at low temperature  

Microsoft Academic Search

The treatment of domestic sewage at low temperature of 13°C was investigated in a two-step system consisting of an anaerobic filter (AF) +an anaerobic hybrid (AH) reactor operated at different hydraulic retention times (HRTs). The AF reactor was efficient in the removal of suspended COD, viz. 81%, 58% and 57% at an HRT of, respectively, 4, 2 and 3h. For

Tarek A. Elmitwalli; Kim L. T. Oahn; Grietje Zeeman; Gatze Lettinga

2002-01-01

381

Anaerobic degradation of aircraft deicing fluid (ADF) in upflow anaerobic sludge blanket (UASB) reactors and the fate of ADF additives  

Microsoft Academic Search

A central composite design was employed to methodically investigate anaerobic treatment of aircraft deicing fluid (ADF) in bench-scale Upflow Anaerobic Sludge Blanket (UASB) reactors. A total of 23 runs at 17 different operating conditions were conducted in continuous mode. The development of four empirical models describing process responses (i.e., chemical oxygen demand (COD) removal efficiency, biomass specific acetoclastic activity, methane

Thi Tham Pham

2002-01-01

382

Microbiology of Animal Bite Wound Infections  

PubMed Central

Summary: The microbiology of animal bite wound infections in humans is often polymicrobial, with a broad mixture of aerobic and anaerobic microorganisms. Bacteria recovered from infected bite wounds are most often reflective of the oral flora of the biting animal, which can also be influenced by the microbiome of their ingested prey and other foods. Bacteria may also originate from the victim's own skin or the physical environment at the time of injury. Our review has focused on bite wound infections in humans from dogs, cats, and a variety of other animals such as monkeys, bears, pigs, ferrets, horses, sheep, Tasmanian devils, snakes, Komodo dragons, monitor lizards, iguanas, alligators/crocodiles, rats, guinea pigs, hamsters, prairie dogs, swans, and sharks. The medical literature in this area has been made up mostly of small case series or case reports. Very few studies have been systematic and are often limited to dog or cat bite injuries. Limitations of studies include a lack of established or inconsistent criteria for an infected wound and a failure to utilize optimal techniques in pathogen isolation, especially for anaerobic organisms. There is also a lack of an understanding of the pathogenic significance of all cultured organisms. Gathering information and conducting research in a more systematic and methodical fashion through an organized research network, including zoos, veterinary practices, and rural clinics and hospitals, are needed to better define the microbiology of animal bite wound infections in humans. PMID:21482724

Abrahamian, Fredrick M.; Goldstein, Ellie J. C.

2011-01-01

383

Dentigenous infectious foci - a risk factor of infective endocarditis  

PubMed Central

Summary Background Dentigenous, infectious foci are frequently associated with the development of various diseases. The role of such foci in the evolution of endocarditis still remains unclear. This article presents the concluding results of an interdisciplinary study verifying the influence of dentigenous, infectious foci on the development of infective endocarditis. Material/Methods The study subjects were 60 adult patients with history of infective endocarditis and coexistent acquired heart disease, along with the presence at least 2 odontogenic infectious foci (ie, 2 or more teeth with gangrenous pulp and periodontitis). The group had earlier been qualified for the procedure of heart valve replacement. Swabs of removed heart valve tissue with inflammatory lesions and blood were then examined microbiologically. Swabs of root canals and their periapical areas, of periodontal pockets, and of heart valves were also collected. Results Microbial flora, cultured from intradental foci, blood and heart valves, fully corresponded in 14 patients. This was accompanied in almost all cases by more advanced periodontitis (2nd degree, Scandinavian classification), irrespective of the bacterial co-occurrence mentioned. In the remaining patients, such consistency was not found. Conclusions Among various dentigenous, infectious foci, the intradental foci appear to constitute a risk factor for infective endocarditis. PMID:22293883

Wisniewska-Spychala, Beata; Sokalski, Jerzy; Grajek, Stefan; Jemielity, Marek; Trojnarska, Olga; Choroszy-Krol, Irena; Sojka, Anna; Maksymiuk, Tomasz

2012-01-01

384

Anaerobic work capacity in elite wheelchair athletes.  

PubMed

To study the anaerobic work capacity in wheelchair athletes, 67 elite wheelchair athletes (50 male) were studied in a 30-second sprint test on a computer-controlled wheelchair ergometer during the World Championships and Games for the Disabled in Assen (1990). The experimental set-up (ergometer, protocol) proved to be adequate in terms of power output (P30, P5) velocity and heart rate. Male and female athletes were comparable with respect to personal characteristics (age, body weight, training hours). Track athletes (classified in 4 different functional classes) showed a class-related mean power output (P30: mean power produced during the 30-second sprint period) of 23, 68, 100, and 138 W for the male athletes (n = 38) and 38, 77, and 76 W for females in the upper three classes (n = 10). Sprint power was low for the group of subjects with cerebral palsy (35 W; mixed, n = 6) and relatively high for the amputee group (121 W; mixed, n = 6), female basketball players (81 W; n = 5), and two male field athletes (110 W). Significant differences between male and female athletes were found for P30 and P5 (highest mean power output over any of the six 5-second periods). As was to be expected, mean maximum heart rate in the sprint test varied significantly between the track groups from 112 (high lesion group) to 171 beats/minute(-1) (low lesion group) but not for both genders. The lower P30 in the T1 and T2 groups must be explained not only by the reduced functional muscle mass and impaired coordination but also by phenomena of cardiovascular dysfunction. Based on the performance parameters, the functional classification of the track athletes into four groups seems adequate. P30 was significantly associated with the personal characteristics of gender and hours of training. A significant correlation was found between P30 and sprint performance times for 200 meters (r = -0.79). No correlation was found between either of the forms of power output and the marathon times. Anaerobic wheelchair work capacity can be adequately studied with the 30-second sprint test that was used in this study. Anaerobic work capacity is highly variable among elite wheelchair athletes with different disabilities and from different sports disciplines and appeared quite strongly influenced by functionality, hours of training, and gender. PMID:9354488

van der Woude, L H; Bakker, W H; Elkhuizen, J W; Veeger, H E; Gwinn, T

1997-01-01

385

Anaerobic digestibility of marine microalgae Phaeodactylum tricornutum in a lab-scale anaerobic membrane bioreactor  

Microsoft Academic Search

The biomass of industrially grown Phaeodactylum tricornutum was subjected in a novel way to bio-methanation at 33A degrees C, i.e., in an anaerobic membrane bioreactor (AnMBR) at a hydraulic retention time of 2.5 days, at solid retention times of 20 to 10 days and at loading rates in the range of 2.6-5.9 g biomass-COD L(-1) day(-1) with membrane fluxes ranging

C. Zamalloa; J. De Vrieze; N. Boon; W. Verstraete

2012-01-01

386

Low temperature treatment of domestic sewage in upflow anaerobic sludge blanket and anaerobic hybrid reactors  

Microsoft Academic Search

The treatment of sewage at a temperature of 13°C was investigated in three reactors (each 3.84 litre) a UASB and two anaerobic hybrid (AH) reactors with small sludge granules with an average diameter of 0.73mm. The media used in the AH reactors were vertical polyurethane foam sheets. The reactors were operated at a HRT of 8h. The use of small

Tarek A. Elmitwalli; Marcel H. Zandvoort; Grietje Zeeman; Harry Bruning; Gatze Lettinga

1999-01-01

387

Anaerobic digestion of secondary residuals from an anaerobic bioreactor at a brewery to enhance bioenergy generation  

Microsoft Academic Search

Many beer breweries use high-rate anaerobic digestion (AD) systems to treat their soluble high-strength wastewater. Biogas\\u000a from these AD systems is used to offset nonrenewable energy utilization in the brewery. With increasing nonrenewable energy\\u000a costs, interest has mounted to also digest secondary residuals from the high-rate digester effluent, which consists of yeast\\u000a cells, bacteria, methanogens, and small (hemi)cellulosic particles. Mesophilic

Benjamin T. Bocher; Matthew T. Agler; Marcelo L. Garcia; Allen R. Beers; Largus T. Angenent

2008-01-01

388

Development of anaerobic migrating blanket reactor (AMBR), a novel anaerobic treatment system.  

PubMed

A novel anaerobic treatment system, the anaerobic migrating blanket reactor (AMBR), was developed after completing a parallel study with upflow anaerobic sludge blanket (UASB) and anaerobic sequencing batch reactor (ASBR) processes. Using sucrose as the main component of a synthetic wastewater, the AMBR achieved a maximum chemical oxygen demand (COD) loading rate of 30 g.l-1.day-1 at a 12-h hydraulic retention time (HRT). This resulted in a standard methane production rate (SMPR) of 6.51.l-1.day-1 and an average methane-based COD (MCOD) removal efficiency of 62.2%. A key element in granular biomass formation was migration of the biomass blanket through the reactor. Although a carbohydrate-rich wastewater was used, no separate pre-acidification was required for the AMBR, because of high mixing intensities and wash out of acidogenic bacteria. In contrast, the absence of pre-acidification created "bulking" problems (caused by abundant acidogenic bacteria at the surface of granules) in a UASB reactor, operated under conditions similar to that of the AMBR. As a result, a maximum COD loading rate and SMPR of 21 g.l-1.day-1 and 4.91.l-1.day-1 were achieved, respectively, for the UASB reactor at a 12-h HRT. These values were 18 g.l-1.day-1 and 3.71.l-1.day-1, respectively, for an ASBR at a 12-h HRT. Hence, the performance of the AMBR in treating a carbohydrate-rich wastewater was found to be superior in terms of maximum loading rate and SMPR. PMID:11329676

Angenent, L T; Sung, S

2001-05-01

389

PCB dechlorination in anaerobic soil slurry reactors  

SciTech Connect

Many industrial locations, including the US Department of Energy`s, have identified needs for treatment of polychlorinated biphenyl (PCB) wastes and remediation of PCB-contaminated sites. Biodegradation of PCBs is a potentially effective technology for the treatment of PCB-contaminated soils and sludges, including mixed wastes; however, a practical remediation technology has not yet been demonstrated. In laboratory experiments, soil slurry bioreactors inoculated with microorganisms extracted from PCB-contaminated sediments from the Hudson River have been used to obtain anaerobic dechlorination of PCBS. The onset of dechlorination activity can be accelerated by addition of nutritional amendments and inducers. After 15 weeks of incubation with PCB-contaminated soil and nutrient solution, dechlorination has been observed under several working conditions. The best results show that the average chlorine content steadily dropped from 4.3 to 3.5 chlorines per biphenyl over a 15-week period.

Klasson, K.T.; Evans, B.S.

1993-11-29

390

Cellulase production by the anaerobic digestion process  

SciTech Connect

An anaerobic digestion process is described for the production of cellulolytic enzymes using a methanogenic cellulose-enrichment culture. After a heat treatment designed to destroy all but spore-forming bacteria, this culture produced cellulase from a variety of cellulosic materials as well as from cellobiose. The enzyme system contained endo- and exoglucanase, acted on filter paper, and showed cellobiase and xylanase activities. It was stable at 2/sup 0/C under aerobic conditions and showed a pH optimum at 5 and a temperature optimum at 50/sup 0/C. Endoglucanase and filter paper activities were mostly exogenic, whereas cellobiase and xylanase activities were cell associated. The cellulolytic activity produced by this mixed culture was comparable to that of commercially available fungal preparations, and the process could be useful as an alternate source for these enzymes.

Khan, A.W.; van den Berg, L.

1981-01-01

391

Monitoring and control of anaerobic reactors.  

PubMed

The current status in monitoring and control of anaerobic reactors is reviewed. The influence of reactor design and waste composition on the possible monitoring and control schemes is examined. After defining the overall control structure, and possible control objectives, the possible process measurements are reviewed in detail. In the sequel, possible manipulated variables, such as the hydraulic retention time, the organic loading rate, the sludge retention time, temperature, pH and alkalinity are evaluated with respect to the two main reactor types: high-rate and low-rate. Finally, the different control approaches that have been used are comprehensively described. These include simple and adaptive controllers, as well as more recent developments such as fuzzy controllers, knowledge-based controllers and controllers based on neural networks. PMID:12747567

Pind, Peter F; Angelidaki, Irini; Ahring, Birgitte K; Stamatelatou, Katerina; Lyberatos, Gerasimos

2003-01-01

392

Antimicrobial susceptibility of anaerobic bacteria in New Zealand: 1999-2003  

Microsoft Academic Search

Objectives: Routine susceptibility testing of all anaerobic organisms is not advocated, but it is useful for laboratories to test periodically for anaerobic organisms and provide local susceptibility data to guide therapy.Thisstudy reports thenational trendof antibiotic susceptibilityof clinically significant anaerobes in New Zealand. Methods: Clinical isolates were tested using standardized methods against a range of antibiotics commonly used to treat anaerobic

Sally A. Roberts; Keith P. Shore; Susan D. Paviour; David Holland; Arthur J. Morris

2006-01-01

393

The anaerobic life of Bacillus subtilis: Cloning of the genes encoding the respiratory nitrate reductase system  

Microsoft Academic Search

The Gram-positive soil bacterium Bacillus subtilis, generally regarded as an aerobe, grows under strict anaerobic conditions using nitrate as an electron acceptor and should be designated as a facultative anaerobe. Growth experiments demonstrated a lag phase of 24 to 36 hours after the shift from aerobic, to the onset of anaerobic respiratory growth. Anaerobically adapted cells grew without further lag

Tamara Hoffmann; Barbara Troup; Alexandra Szabo; Christoph Hungerer; Dieter Jahn

1995-01-01

394

Mediation of sulfur speciation by a Black Sea facultative anaerobe  

SciTech Connect

Shewanella putrefaciens, a respiratory facultative anaerobe isolated from the Black Sea, can reduce thiosulfate, sulfite, and elemental sulfur to sulfide readily and quantitatively. This widespread and anaerobically versatile microorganism, which is incapable of reducing sulfate, uses oxidized sulfur intermediates as electron acceptors during the respiratory oxidation of organic matter. Because of its widespread distribution and abundance, it may play a significant role in sulfur and trace metal cycling in the Black Sea and in other marine and freshwater anaerobic environments. 28 refs., 3 figs., 1 tab.

Perry, K.A.; Kostka, J.E.; Luther, G.W. III (Univ. of Delaware, Lewes (United States)); Nealson, K.H. (Univ. of Wisconsin, Milwaukee (United States))

1993-02-05

395

Electron beam/biological processing of anaerobic and aerobic sludge  

NASA Astrophysics Data System (ADS)

Besides common chemical and biological methods, the radiation technology is a promising way of sludge treatment. The paper describes possibilities of combined accelerated electrons/biological processing of both anaerobic and aerobic sludge. Besides one-shot experiments, experimental reactors for the simulation of anaerobic processes have been used. Main effort has been aimed to decrease organic compounds concentration and overall volume of solids, to improve some physico-chemical parameters of sludge, to validate hygienisation effects of the ionising radiation, and in the case of anaerobic sludge, to increase the volume of the produced biogas. Positive effects of the electron beam processing have been observed on all previously named parameters.

?uba, V.; Pospíšil, M.; Mú?ka, V.; Jení?ek, P.; Dohányos, M.; Zábranská, J.

2003-01-01

396

Heartworm infection.  

PubMed

Dirofilaria immitis is an epizootic filarial parasite that most often infects domestic dogs. This article provides information about the life cycle of Dirofilaria immitis as well as the epidemiology, diagnosis, clinical signs, and treatment of heartworm infection. PMID:3328398

Knight, D H

1987-11-01

397

Campylobacter Infections  

MedlinePLUS

Campylobacter infection is a common foodborne illness. You get it from eating raw or undercooked poultry. You ... whether you need to take antibiotics. To prevent campylobacter infection, cook poultry thoroughly. Use a separate cutting ...

398

Atmospheric vs. anaerobic processing of metabolome samples for the metabolite profiling of a strict anaerobic bacterium, Clostridium acetobutylicum.  

PubMed

Well-established metabolome sample preparation is a prerequisite for reliable metabolomic data. For metabolome sampling of a Gram-positive strict anaerobe, Clostridium acetobutylicum, fast filtration and metabolite extraction with acetonitrile/methanol/water (2:2:1, v/v) at -20°C under anaerobic conditions has been commonly used. This anaerobic metabolite processing method is laborious and time-consuming since it is conducted in an anaerobic chamber. Also, there have not been any systematic method evaluation and development of metabolome sample preparation for strict anaerobes and Gram-positive bacteria. In this study, metabolome sampling and extraction methods were rigorously evaluated and optimized for C. acetobutylicum by using gas chromatography/time-of-flight mass spectrometry-based metabolomics, in which a total of 116 metabolites were identified. When comparing the atmospheric (i.e., in air) and anaerobic (i.e., in an anaerobic chamber) processing of metabolome sample preparation, there was no significant difference in the quality and quantity of the metabolomic data. For metabolite extraction, pure methanol at -20°C was a better solvent than acetonitrile/methanol/water (2:2:1, v/v/v) at -20°C that is frequently used for C. acetobutylicum, and metabolite profiles were significantly different depending on extraction solvents. This is the first evaluation of metabolite sample preparation under aerobic processing conditions for an anaerobe. This method could be applied conveniently, efficiently, and reliably to metabolome analysis for strict anaerobes in air. Biotechnol. Bioeng. 2014;111: 2528-2536. © 2014 Wiley Periodicals, Inc. PMID:24942337

Lee, Sang-Hyun; Kim, Sooah; Kwon, Min-A; Jung, Young Hoon; Shin, Yong-An; Kim, Kyoung Heon

2014-12-01

399

Anaerobic growth of microorganisms with chlorate as an electron acceptor.  

PubMed

The ability of microorganisms to use chlorate (ClO(3)) as an electron acceptor for respiration under anaerobic conditions was studied in batch and continuous tests. Complex microbial communities were cultivated anaerobically in defined media containing chlorate, all essential minerals, and acetate as the sole energy and carbon source. It was shown that chlorate was reduced to chloride, while acetate was oxidized to carbon dioxide and water and used as the carbon source for synthesis of new biomass. A biomass yield of 1.9 to 3.8 g of volatile suspended solids per equivalent of available electrons was obtained, showing that anaerobic growth with chlorate as an electron acceptor gives a high energy yield. This indicates that microbial reduction of chlorate to chloride in anaerobic systems is coupled with electron transport phosphorylation. PMID:16348537

Malmqvist, A; Welander, T; Gunnarsson, L

1991-08-01

400

Agar medium for gas-liquid chromatography of anaerobes.  

PubMed

This study evaluates a method of performing gas-liquid chromatography (GLC) by direct extraction of fatty acids from agar for identification of clinically significant anaerobic bacteria. The potential use of agar cultures for GLC was studied by comparing chromatograms of 117 clinically isolated anaerobes grown in peptone yeast glucose broth and chopped meat carbohydrate broth, and on enriched brucella blood agar. For 98 of 117 anaerobes, fatty acid patterns from agar cultures were similar to those in broth. Significant differences were only found with Streptococcus intermedius, Clostridium perfringens, Clostridium tertium, and Actinomyces species, which produced less of certain fatty acids on agar than in broth. Results of this study indicate that GLC of short chain fatty acids produced on agar medium by anaerobes, combined with simple tests such as Gram's stain and colonial morphology, may allow fir direct presumptive genus identification from an initial pure agar culture. PMID:3940426

Pankuch, G A; Appelbaum, P C

1986-01-01

401

Interactions of rumen chitinolytic bacterium, Clostridium tertium with anaerobic fungi  

E-print Network

Interactions of rumen chitinolytic bacterium, Clostridium tertium with anaerobic fungi B Hodrova J spore forming, Gram- positive rods. The isolate ChK5 was identified as Clostridium tertium and further

Paris-Sud XI, Université de

402

ANAEROBIC BIOTRANSFORMATIONS OF POLLUTANT CHEMICALS IN AQUIFERS (JOURNAL VERSION)  

EPA Science Inventory

Anaerobic microbial communities sampled from either a methanogenic or sulfate-reducing aquifer site have been tested for their ability to degrade a variety of groundwater pollutants, including halogenated aromatic compounds, simple alkyl phenols and tetrachloroethylene. The haloa...

403

Decolourisation of textile wastewater in a submerged anaerobic membrane bioreactor.  

PubMed

Azo dye decolourisation can be easily achieved by biological reduction under anaerobic conditions. The aim of this study was to evaluate the applicability of submerged anaerobic membrane bioreactors (SAMBRs) for the decolourisation of dyeing wastewater containing azo dyes. The reactive orange 16 was used as model of an azo dye. The results demonstrated that very high decolourisation (higher than 99%) can be achieved by SAMBRs. Although decolourisation was not significantly influenced by the azo dye concentrations up to 3.2 g L(-1), methane production was greatly inhibited (up to 80-85%). Since volatile fatty acids accumulated in the treatment system with the azo dye concentration increase, methanogenes seem to be the most sensitive microbial populations of the anaerobic ecological community. The results demonstrated that anaerobic process combined with membrane filtration can deal with highly concentrated wastewaters that result from stream separation of industrial discharges. PMID:22613894

Spagni, Alessandro; Casu, Stefania; Grilli, Selene

2012-08-01

404

Energy transduction by anaerobic ferric iron respiration in Thiobacillus ferrooxidans  

SciTech Connect

Formate-grown cells of the obligately chemolithoautotrophic acidophile Thiobacillus ferrooxidans were capable of formate- and elemental sulfur-dependent reduction of ferric iron under anaerovic conditions. Under aerobic conditions, both oxygen and ferric iron could be simultaneously used as electron acceptors. To investigate whether anaerobic ferric iron respiration by T. ferrooxidans is an energy-transducing process, uptake of amino acids was studied. Glycine uptake by starved cells did not occur in the absence of an electron donor, neither under aerobic conditions nor under anaerobic conditions. Uptake of glycine could be driven by formate- and ferrous iron-dependent oxygen uptake. Under anaerobic conditions, ferric iron respiration with the electron donors formate and elemental sulfur could energize glycine uptake. Glycine uptake was inhibited by the uncoupler 2,4-dinitrophenol. The results indicate that anaerobic ferric iron respiration can contribute to the energy budget of T. ferrooxidans.

Pronk, J.T.; Liem, K.; Bos, P.; Kuenen, J.G. (Delft Univ. of Technology (Netherlands))

1991-07-01

405

Modeling anaerobic digestion of microalgae using ADM1.  

PubMed

The coupling between a microalgal pond and an anaerobic digester is a promising alternative for sustainable energy production by transforming carbon dioxide into methane using solar energy. In this paper, we demonstrate the ability of the original ADM1 model and a modified version (based on Contois kinetics for the hydrolysis steps) to represent microalgae anaerobic digestion. Simulations were compared to experimental data of an anaerobic digester fed with Chlorella vulgaris. The modified ADM1 fits adequately the data for the considered 140 day experiment encompassing a variety of influent load and flow rates. It turns out to be a reliable predictive tool for optimising the coupling of microalgae with anaerobic digestion processes. PMID:21536430

Mairet, Francis; Bernard, Olivier; Ras, Monique; Lardon, Laurent; Steyer, Jean-Philippe

2011-07-01

406

Culturing and Maintaining Clostridium difficile in an Anaerobic Environment  

PubMed Central

Clostridium difficile is a Gram-positive, anaerobic, sporogenic bacterium that is primarily responsible for antibiotic associated diarrhea (AAD) and is a significant nosocomial pathogen. C. difficile is notoriously difficult to isolate and cultivate and is extremely sensitive to even low levels of oxygen in the environment. Here, methods for isolating C. difficile from fecal samples and subsequently culturing C. difficile for preparation of glycerol stocks for long-term storage are presented. Techniques for preparing and enumerating spore stocks in the laboratory for a variety of downstream applications including microscopy and animal studies are also described. These techniques necessitate an anaerobic chamber, which maintains a consistent anaerobic environment to ensure proper conditions for optimal C. difficile growth. We provide protocols for transferring materials in and out of the chamber without causing significant oxygen contamination along with suggestions for regular maintenance required to sustain the appropriate anaerobic environment for efficient and consistent C. difficile cultivation. PMID:24084491

Edwards, Adrianne N.; Suarez, Jose M.; McBride, Shonna M.

2014-01-01

407

Anaerobic Growth of Microorganisms with Chlorate as an Electron Acceptor  

PubMed Central

The ability of microorganisms to use chlorate (ClO3-) as an electron acceptor for respiration under anaerobic conditions was studied in batch and continuous tests. Complex microbial communities were cultivated anaerobically in defined media containing chlorate, all essential minerals, and acetate as the sole energy and carbon source. It was shown that chlorate was reduced to chloride, while acetate was oxidized to carbon dioxide and water and used as the carbon source for synthesis of new biomass. A biomass yield of 1.9 to 3.8 g of volatile suspended solids per equivalent of available electrons was obtained, showing that anaerobic growth with chlorate as an electron acceptor gives a high energy yield. This indicates that microbial reduction of chlorate to chloride in anaerobic systems is coupled with electron transport phosphorylation. Images PMID:16348537

Malmqvist, Asa; Welander, Thomas; Gunnarsson, Lars

1991-01-01

408

Design of an anaerobic digester in Quebec, Canada  

E-print Network

.In response to the future Quebec, Canada regulations prohibiting landfilling of organic matter by 2020, EBI, a waste management company located near Montreal is considering constructing an anaerobic digester. This thesis ...

Bouaziz, Alexandre N. (Alexandre Nathanel)

2014-01-01

409

INCREASE OF INDICATOR ORGANISMS FOLLOWING ANAEROBIC DIGESTION AND CENTRIFUGE DEWATERING.  

EPA Science Inventory

The Water Environment Research Foundation (WERF) recently published a report titled ?Examination of Reactivation and Regrowth of Fecal Coliforms in Anaerobically Digested Sludges?. Seven full-scale publicly owned treatment facilities were sampled several times to determine if bac...

410

The identification of anaerobic bacteria using MALDI-TOF MS  

Microsoft Academic Search

Matrix Assisted Laser Desorption and Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) has gained more and more popularity for the identification of bacteria. Several studies show that bacterial diagnosticis is being revolutionized by the application of MALDI-TOF MS. For anaerobic bacteria, MALDI-TOF MS has been used for the identification of Prevotella spp., Fusobacterium spp., Clostridium spp., Bacteroides spp. and Gram-positive anaerobic

A. C. M. Veloo; G. W. Welling; J. E. Degener

2011-01-01

411

Anaerobic biodegradation of Para -cresol under three reducing conditions  

Microsoft Academic Search

The anaerobic degradation ofp-cresol was studied with one sediment source under three reducing conditions—denitrifying, sulfidogenic, and methanogenic.\\u000a Loss ofp-cresol (1 mM) in all the anaerobic systems took initially 3 to 4 weeks. In acclimated culturesp-cresol was degraded in less than a week.p-Cresol was completely metabolized under denitrifying, sulfidogenic, and methanogenic conditions, with formation of nitrogen\\u000a gas, loss of sulfate, and

Max M. Häggblom; Maria D. Rivera; Ingeborg D. Bossert; John E. Rogers; L. Y. Young

1990-01-01

412

Validity and reliability of the Hawaii anaerobic run test.  

PubMed

This study examined the reliability and validity of the Hawaii anaerobic run test (HART) by comparing anaerobic capacity measures obtained to those during the Wingate Anaerobic Test (WAnT). Ninety-six healthy physically active volunteers (age, 22.0 ± 2.8 years; height, 163.9 ± 9.5 cm; body mass, 70.6 ± 14.7 kg; body fat %, 19.29 ± 5.39%) participated in this study. Each participant performed 2 anaerobic capacity tests: the WAnT and the HART by random assignment on separate days. The reliability of the HART was calculated from 2 separate trials of the test and then determined through intraclass correlation coefficients (ICCs). Blood samples were collected, and lactate was analyzed both pretest and posttest for each of the 2 exercise modes. Heart rate and rate of perceived exertion were also measured pre- and post-exercise. Hawaii anaerobic run test peak and mean momentum were calculated as body mass times highest or average split velocity, respectively. Intraclass correlation coefficients between trials of the HART for peak and mean momentum were 0.98 and 0.99, respectively (SEM = 18.8 and 25.7, respectively). Validity of the HART was established through comparison of momentum on the HART with power on the WAnT. High correlations were found between peak power and peak momentum (r = 0.88), as well as mean power and mean momentum (r = 0.94). The HART was considered to be a reliable test of anaerobic power. The HART was also determined to be a valid test of anaerobic power when compared with the WAnT. When testing healthy college-aged individuals, the HART offers an easy and inexpensive alternative maximal effort anaerobic power test to other established tests. PMID:24126898

Kimura, Iris F; Stickley, Christopher D; Lentz, Melissa A; Wages, Jennifer J; Yanagi, Kazuhiko; Hetzler, Ronald K

2014-05-01

413

Enrichment of anaerobic methanotrophs in sulfate-reducing membrane bioreactors  

Microsoft Academic Search

Anaerobic oxidation of methane (AOM) in marine sediments is coupled to sulfate reduction (SR). AOM is mediated by distinct groups of archaea, called anaerobic methanotrophs (ANME). ANME co-exist with sulfate-reducing bacteria, which are also involved in AOM coupled SR. The microorganisms involved in AOM coupled to SR are extremely difficult to grow in vitro. Here, a novel well-mixed submerged-membrane bioreactor

Roel J. W. Meulepas; Christian G. Jagersma; Jarno Gieteling; Cees J. N. Buisman; Alfons J. M. Stams; Piet N. L. Lens

2009-01-01

414

Impact of membrane configuration on fouling in anaerobic membrane bioreactors  

Microsoft Academic Search

The filtration performance of flocculated and granulated configured anaerobic membrane bioreactors (MBR) treating domestic wastewater has been evaluated and compared to conventional aerobic MBR. Immersed hollow fibre (HF) and external tubular membrane geometries were additionally compared with the latter operated in both pumped and gas-lift mode. After 200d of operation, both granular and flocculated anaerobic MBR (AnMBR) suspensions were characterised

I. Martin-Garcia; V. Monsalvo; M. Pidou; P. Le-Clech; S. J. Judd; E. J. McAdam; B. Jefferson

2011-01-01

415

[Evaluation for anaerobic culture system: Anoxomat Mart II].  

PubMed

Anoxomat Mart II (Mart Microbiology BV, Lichtenvooorde, Netherlands, Central Scientific Commerce Inc., Tokyo, Japan) is an anaerobic jar apparatus which uses a vacuum pump in combination with catalyst as gas replacement procedure to remove all traces of oxygen. As we had a chance to use Anoxomat Mart II, we compared it with other two anaerobic culture methods; namely AnaeroPack anaero (Mitsubishi Gas Chemical Co., Tokyo, Japan) which employs anaerobic jar method, and Concept400 (RUSKINN TECHNOLOGY LTD, England; Central Scientific Commerce INc., Tokyo, Japan) which uses anaerobic chamber method. We used 10 different species of anaerobic bacteria obtained from ATCC. One strain each of 10 species was cultured and examined for measurement of the sensitibity of an anaerobic indicator, th number of bacteria after 48 hour culture, the diameter of colonies, and MIC value. As a result, the time to reach the anaerobic condition was around 30 minutes by the Mart II against around 60 minutes by the AnaeroPack anaero. There was no difference concerning the number of bacteria after 48 hour culture among three methods. But anaerobic bacteria cultured by Mart II tended to make bigger colonies compared to other two methods in the 5 strains out of 9, except for one strain in which the diameter of colonies could not be measured. On the other hand, the comparison of MIC value showed good correlation in 11 antibiotics out of 12 among three methods. The MIC value of 11 antibiotics fitted within 1-fold difference, and 2-fold difference was observed in only one antibiotic. Mart II is so small that it does cheep consumables. From these reasons, we concluded that Mart II can be one of the useful anerobic culture methods. PMID:17803362

Kikuchi, Yuji; Sasaki, Hiromi; Furuhata, Yukie; Tazawa, Yoko; Horiuchi, Hajime; Okada, Jun

2007-01-01

416

INFLUENCE OF THERMAL PRETREATMENT ON MESOPHILIC ANAEROBIC DIGESTION OF SLUDGES  

Microsoft Academic Search

The anaerobic degradation of sludge is usually limited by the rate of hydrolysis of suspended matter and organic solids. Low temperature pre-treatment (below 80°C) results in incomplete destruction of micro-flora but many enzymes maintain their biocatalytic activity. Increasing hydrolysis through thermal and alkali pre-treatment was studied in an anaerobic thermophilic reactor operating between 70°C and 100°C with hydraulic retention times

Anne Menert; Tarmo Vaalu; Merje Michelis; Viktoria Blonskaja; Ergo Rikmann; Aita Mets; Raivo Vilu

2008-01-01

417

Treatment of methanolic wastewater using anaerobic sequencing batch reactor  

Microsoft Academic Search

Treatment of methanolic wastewater was studied in an anaerobic sequencing batch reactor (ASBR) for a period of 193 days. The results showed that the system worked efficiently when the system volume loading was of 4-8g COD\\/l. d. Both Methanol concentration and bicarbonate play an important role in the anaerobic conversion of methanol. The route by which methanol was converted into

Shao Xiangwen; Peng dangcong

2011-01-01

418

Anaerobic degradation of benzoate to methane by a microbial consortium  

Microsoft Academic Search

A stabilized consortium of microbes which anaerobically degraded benzoate and produced CH4 was established by inoculation of a benzoate-mineral salts medium with sewage sludge; the consortium was routinely subcultured anaerobically in this medium for 3 years. Acetate, formate, H2 and CO2 were identified as intermediates in the overall conversion of benzoate to CH4 by the culture. Radioactivity was equally divided

J. G. Ferry; R. S. Wolfe

1976-01-01

419

Effect of Anaerobic Growth on Quinolone Lethality with Escherichia coli?  

PubMed Central

Quinolone activity against Escherichia coli was examined during aerobic growth, aerobic treatment with chloramphenicol, and anaerobic growth. Nalidixic acid, norfloxacin, ciprofloxacin, and PD161144 were lethal for cultures growing aerobically, and the bacteriostatic activity of each quinolone was unaffected by anaerobic growth. However, lethal activity was distinct for each quinolone with cells treated aerobically with chloramphenicol or grown anaerobically. Nalidixic acid failed to kill cells under both conditions; norfloxacin killed cells when they were grown anaerobically but not when they were treated with chloramphenicol; ciprofloxacin killed cells under both conditions but required higher concentrations than those required with cells grown aerobically; and PD161144, a C-8-methoxy fluoroquinolone, was equally lethal under all conditions. Following pretreatment with nalidixic acid, a shift to anaerobic conditions or the addition of chloramphenicol rapidly blocked further cell death. Formation of quinolone-gyrase-DNA complexes, observed as a sodium dodecyl sulfate (SDS)-dependent drop in cell lysate viscosity, occurred during aerobic and anaerobic growth and in the presence and in the absence of chloramphenicol. However, lethal chromosome fragmentation, detected as a drop in viscosity in the absence of SDS, occurred with nalidixic acid treatment only under aerobic conditions in the absence of chloramphenicol. With PD161144, chromosome fragmentation was detected when the cells were grown aerobically and anaerobically and in the presence and in the absence of chloramphenicol. Thus, all quinolones tested appear to form reversible bacteriostatic complexes containing broken DNA during aerobic growth, during anaerobic growth, and when protein synthesis is blocked; however, the ability to fragment chromosomes and to rapidly kill cells under these conditions depends on quinolone structure. PMID:17043118

Malik, Muhammad; Hussain, Syed; Drlica, Karl

2007-01-01

420

Peak anaerobic power in patients with COPD: gender related differences  

Microsoft Academic Search

The aim of the study was to investigate peak anaerobic power during all-out exercise in patients with COPD. Twenty patients (ten women, ten men) [FEV1 = 50.5 (7.6)% of predicted] and 11 healthy subjects (six women, five men) performed: (1) three maximal sprints on a cycle ergometer to measure peak anaerobic power (P\\u000a max) and optimal velocity (V\\u000a opt), (2) assessment of

R. J. Yquel; F. Tessonneau; M. Poirier; J. Moinard; O. Pillet; G. Manier

2006-01-01

421

Anaerobic propane oxidation in marine hydrocarbon seep sediments  

NASA Astrophysics Data System (ADS)

Propane (C 3H 8) is an abundant hydrocarbon in subsurface reservoirs with significance to atmospheric chemistry and to marine biogeochemistry. The anaerobic oxidation of propane coupled to sulfate reduction may prevent sub-seafloor accumulations of propane from entering the ocean and atmosphere. Anaerobic oxidation of propane has recently been demonstrated in cultures of novel sulfate-reducing bacteria, but has not been directly demonstrated or quantified in nature. In this work we describe a method involving incubation with 13C-propane to quantify rates of anaerobic oxidation of propane in anoxic sediment, and we conclusively demonstrate the oxidation of propane under sulfidic conditions in fresh sediments of a marine hydrocarbon seep. Observed rates of anaerobic oxidation of propane adhere to first-order kinetic behavior, enabling the modification of this method for whole core rate determinations. Whole core rates in nine cores from two hydrocarbon seeps measured 0.04-2100 nmoles C 3H 8 cm -3 day -1 by this method. The seep persistently supplied with more propane displayed substantially higher rates of anaerobic oxidation of propane, by 1-2 orders of magnitude when averaged over the top 10-cm, suggesting the development of the microbial community is strongly modulated by the availability of propane. This work is the first to estimate rates for anaerobic oxidation of propane in any environment, and demonstrates the potential importance of the process as a filter for preventing propane from entering the ocean and atmosphere.

Quistad, Steven D.; Valentine, David L.

2011-04-01

422

Anaerobic treatment of effluents from an industrial polymers synthesis plant  

SciTech Connect

The feasibility of the anaerobic treatment of an industrial polymer synthesis plant effluent was evaluated. The composition of the wastewater includes acrylates, styrene, detergents, a minor amount of silicates and a significant amount of ferric chloride. The average chemical oxygen demand (COD) corresponding is about 2,000 mg/l. The anaerobic biodegradability of the effluent is shown and the toxicity effect on the populations of anaerobic bacteria is evaluated. The results of the anaerobic biodegradation assays show that 62% of the wastewater compounds, measured as COD, could be consumed. An upflow anaerobic sludge blanket (UASB) reactor was used in the evaluation, it has a diameter-height ratio of 1:7, and 4-liter volume. The inoculum was obtained from a UASB pilot plant that treats brewery wastewaters. At the beginning of the operation, the biomass showed an anaerobic activity of 0.58 gCOD/(gVSS {times} d), it decreased only 2.5% in the subsequent 4 months. After 35 days of continuous operation, the reactor was operated at different steady states for 140 days. The COD was maintained at 2,200 mg/l in the feed. The results were: organic loading rate (OLR): 4.3 kg COD/(m{sup 3} {times} d), hydraulic retention time: 12 h, superficial velocity: 1 m/h, average biogas productivity: 290 L CH{sub 4}/kg COD fed, biogas composition: 70--75% methane and a COD removal percentage > 75%.

Araya, P.; Aroca, G.; Chamy, R. [Univ. Catolica de Valparaiso (Chile). School of Biochemical Engineering] [Univ. Catolica de Valparaiso (Chile). School of Biochemical Engineering

1999-06-01

423

Effect of alkaline pretreatment on anaerobic digestion of solid wastes  

SciTech Connect

The introduction of the anaerobic digestion for the treatment of the organic fraction of municipal solid waste (OFMSW) is currently of special interest. The main difficulty in the treatment of this waste fraction is its biotransformation, due to the complexity of organic material. Therefore, the first step must be its physical, chemical and biological pretreatment for breaking complex molecules into simple monomers, to increase solubilization of organic material and improve the efficiency of the anaerobic treatment in the second step. This paper describes chemical pretreatment based on lime addition (Ca(OH){sub 2}), in order to enhance chemical oxygen demand (COD) solubilization, followed by anaerobic digestion of the OFMSW. Laboratory-scale experiments were carried out in completely mixed reactors, 1 L capacity. Optimal conditions for COD solubilization in the first step of pretreatment were 62.0 mEq Ca(OH){sub 2}/L for 6.0 h. Under these conditions, 11.5% of the COD was solubilized. The anaerobic digestion efficiency of the OFMSW, with and without pretreatment, was evaluated. The highest methane yield under anaerobic digestion of the pretreated waste was 0.15 m{sup 3} CH{sub 4}/kg volatile solids (VS), 172.0% of the control. Under that condition the soluble COD and VS removal were 93.0% and 94.0%, respectively. The results have shown that chemical pretreatment with lime, followed by anaerobic digestion, provides the best results for stabilizing the OFMSW.

Lopez Torres, M. [National Center for Scientific Researcher (CNIC), Environmental Pollution Department (DECA), Ave. 25 y 158, Cubanacan, Playa, Havana City (Cuba)], E-mail: matilde.lopez@cnic.edu.cu; Espinosa Llorens, Ma. del C. [National Center for Scientific Researcher (CNIC), Environmental Pollution Department (DECA), Ave. 25 y 158, Cubanacan, Playa, Havana City (Cuba)

2008-11-15

424

Diversity of Anaerobic Microbes in Spacecraft Assembly Clean Rooms ? †  

PubMed Central

Although the cultivable and noncultivable microbial diversity of spacecraft assembly clean rooms has been previously documented using conventional and state-of-the-art molecular techniques, the occurrence of obligate anaerobes within these clean rooms is still uncertain. Therefore, anaerobic bacterial communities of three clean-room facilities were analyzed during assembly of the Mars Science Laboratory rover. Anaerobic bacteria were cultured on several media, and DNA was extracted from suitable anaerobic enrichments and examined with conventional 16S rRNA gene clone library, as well as high-density phylogenetic 16S rRNA gene microarray (PhyloChip) technologies. The culture-dependent analyses predominantly showed the presence of clostridial and propionibacterial strains. The 16S rRNA gene sequences retrieved from clone libraries revealed distinct microbial populations associated with each clean-room facility, clustered exclusively within gram-positive organisms. PhyloChip analysis detected a greater microbial diversity, spanning many phyla of bacteria, and provided a deeper insight into the microbial community structure of the clean-room facilities. This study presents an integrated approach for assessing the anaerobic microbial population within clean-room facilities, using both molecular and cultivation-based analyses. The results reveal that highly diverse anaerobic bacterial populations persist in the clean rooms even after the imposition of rigorous maintenance programs and will pose a challenge to planetary protection implementation activities. PMID:20228115

Probst, Alexander; Vaishampayan, Parag; Osman, Shariff; Moissl-Eichinger, Christine; Andersen, Gary L.; Venkateswaran, Kasthuri

2010-01-01

425

Anaerobic Benzene Oxidation via Phenol in Geobacter metallireducens  

PubMed Central

Anaerobic activation of benzene is expected to represent a novel biochemistry of environmental significance. Therefore, benzene metabolism was investigated in Geobacter metallireducens, the only genetically tractable organism known to anaerobically degrade benzene. Trace amounts (<0.5 ?M) of phenol accumulated in cultures of Geobacter metallireducens anaerobically oxidizing benzene to carbon dioxide with the reduction of Fe(III). Phenol was not detected in cell-free controls or in Fe(II)- and benzene-containing cultures of Geobacter sulfurreducens, a Geobacter species that cannot metabolize benzene. The phenol produced in G. metallireducens cultures was labeled with 18O during growth in H218O, as expected for anaerobic conversion of benzene to phenol. Analysis of whole-genome gene expression patterns indicated that genes for phenol metabolism were upregulated during growth on benzene but that genes for benzoate or toluene metabolism were not, further suggesting that phenol was an intermediate in benzene metabolism. Deletion of the genes for PpsA or PpcB, subunits of two enzymes specifically required for the metabolism of phenol, removed the capacity for benzene metabolism. These results demonstrate that benzene hydroxylation to phenol is an alternative to carboxylation for anaerobic benzene activation and suggest that this may be an important metabolic route for benzene removal in petroleum-contaminated groundwaters, in which Geobacter species are considered to play an important role in anaerobic benzene degradation. PMID:24096430

Tremblay, Pier-Luc; Chaurasia, Akhilesh Kumar; Smith, Jessica A.; Bain, Timothy S.; Lovley, Derek R.

2013-01-01

426

Biogas recovery from a temperate climate covered anaerobic pond.  

PubMed

New Zealand has over 1000 anaerobic waste stabilisation ponds treating wastewater from farms and industry. Traditional anaerobic ponds were not designed to optimise anaerobic digestion to produce biogas and are therefore uncovered, releasing biogas to the atmosphere, which can cause odour problems and contributes to GHG emissions. The biogas production and treatment performance of an anaerobic piggery pond retrofitted with a perimeter cover working under field conditions was monitored over a 14 month period. The cover design proved successful in capturing biogas, mitigating odour and GHG issues and coping with New Zealand weather conditions. High solids removal rates (73% and 86% for TS and VS respectively) were achieved. An annual average biogas methane production rate of 0.263 m(3) CH(4)/kgVS(added) was observed, which is similar to gas production rates of mesophilic farm waste digesters, and indicates that the prolonged hydraulic and solids retention times of covered anaerobic ponds can fully compensate for lower operating temperatures. These results suggest that covered anaerobic ponds treating agricultural wastes in New Zealand have great potential to reduce odour and GHG emissions and recover renewable energy, while producing an easy to handle effluent for land irrigation or further treatment. PMID:20182082

Heubeck, S; Craggs, R J

2010-01-01

427

Hydrogen Biogeochemistry in Anaerobic and Photosynthetic Ecosystems  

NASA Technical Reports Server (NTRS)

The simple biochemistry of molecular hydrogen is central to a large number of microbial processes, affecting the interaction of organisms with each other and with the environment. In anoxic sediments, a great majority of microbial redox processes involve hydrogen as a reactant, product or potential by-product. Accordingly, the energetics (thermodynamics) of each of these processes is affected by variations in local H2 concentrations. It has long been established that this effect is important in governing microbe-microbe interactions and there are multiple demonstrations that "interspecies hydrogen transfer" can alter the products of, inhibit/stimulate, or even reverse microbial metabolic reactions. In anoxic sediments, H2 concentrations themselves are thought to be controlled by the thermodynamics of the predominant H2-consuming microbial process. In sediments from Cape Lookout Bight, this relationship quantitatively describes the co-variation of H2 concentrations with temperature (for methanogens and sulfate reducers) and with sulfate concentration (for sulfate reducers). The quantitative aspect is import= for two reasons: 1) it permits the modeling of H2-sensitive biogeochemistry, such as anaerobic methane oxidation or pathways of organic matter remineralization, as a function of environmental controls; 2) for such a relationship to be observed requires that intracellular biochemistry and bioenergetics are being directly expressed in a component of the extracellular medium. H2 could therefore be utilized a non-invasive probe of cellular energetic function in intact microbial ecosystems. Based on the latter principle we have measured down-core profiles of H2 and other relevant physico-chemical parameters in order to calculate the metabolic energy yields (DG) that support microbial metabolism in Cape Lookout Bight sediments. Methanogens in this system apparently function with energy yields significantly smaller than the minimum requirements suggested by pure culture studies. Our recent work has extended the study of hydrogen to cyanobacterial mat communities. The large amounts of reducing power generated during photosynthetic activity carry the potential to contribute a swamping term to the H2 economy of the anaerobic microbial populations within the mat - and thereby to alter the population structure and biogeochemical function of the mat as a whole. In hypersaline microbial mats, we observe a distinct diel cycle in H2 production and a substantial corresponding flux. On an early Earth dominated by microbial mats, this transmission of photosynthetic reducing power may have carried important implications for both biospheric and atmospheric evo