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1.
Mymensingh Med J ; 32(2): 580-583, 2023 Apr.
Article in English | MEDLINE | ID: mdl-37002773

ABSTRACT

Giant cell tumor of tendon sheath arises from the synovium of tendon sheaths, joints, or bursa, mostly affects adults between 30 and 50 years of age, and is slightly more common in females. It corresponds to a localized form of pigmented villonodular synovitis (PVNS). Typically occur in the hand where they represent the second most common type of soft tissue tumors after synovial ganglions. Bilateral giant cell tumor of tendon sheath of tendoachilles is a rare presentation. We report the case of a 22-years-old female presenting with pain in both ankles without any history of trauma. On clinical examination, tenderness on both tendoachilles and local indurations were observed. Ultrasonography showed focal thickening of Achilles tendon bilaterally, and Doppler demonstrated increased flow in peritendinous area. MRI findings showed that most of the tumor had intermediate signal intensity and portions of the tumor had low signal intensity. Fine needle aspiration cytology confirmed the diagnosis of giant cell tumor of tendon sheath. Excision biopsy was done with no recurrence on subsequent follow-up.


Subject(s)
Giant Cell Tumors , Synovitis, Pigmented Villonodular , Adult , Humans , Female , Young Adult , Giant Cell Tumors/diagnosis , Giant Cell Tumors/pathology , Giant Cell Tumors/surgery , Synovitis, Pigmented Villonodular/diagnosis , Synovitis, Pigmented Villonodular/surgery , Synovitis, Pigmented Villonodular/pathology , Magnetic Resonance Imaging , Biopsy , Tendons/diagnostic imaging
2.
Mymensingh Med J ; 30(2): 420-425, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33830123

ABSTRACT

Different types of solitary brain lesions and also tumefactive demyelinating lesions exhibit many features on CT and MRI that are characteristics of malignancy and surgical biopsy is often performed in suspected tumour. Proton MR Spectroscopy has been used to differentiate different type of these solitary brain lesions. Our purpose is to determine whether MR spectroscopy is able to improve preoperative diagnostic accuracy in case of intracranial solitary tumors. This cross sectional study was carried out among 44 patients who were referred to Radiology and Imaging Department by Neurosurgery and Neuro-medicine department of BSMMU, Dhaka, Bangladesh as MRI suspected glioma for MRS scan during the period of 24 months. MRS was performed in 44 patients with suspected glioma. Metabolic ratio of choline: Cr, NAA: Cr, Lactate: Cr was calculated in short and intermediated echo times (TES). Tumors were subdivided into neoplasm and inflammatory mass. Neoplasm was again subdivided into glioblastoma multiforme and solitary metastasis. The patients were followed up and surgical resection biopsy reports were collected. MRS findings and histopathological findings were then correlated. In this study 68.18% of patients were diagnosed as Glioblastoma multiform by MRS and also in histopathology 18.18%. Patient was diagnosed as solitary metastasis in MRS and 20.45%. Patient was diagnosed as solitary metastasis by histopathology and 13.64%. Patient was diagnosed as abscess in MRS while in histopathology 11.37% patients were diagnosed as abscess.


Subject(s)
Brain Neoplasms , Glioma , Bangladesh , Brain , Brain Neoplasms/diagnostic imaging , Cross-Sectional Studies , Humans , Magnetic Resonance Spectroscopy
3.
Mymensingh Med J ; 29(1): 162-168, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31915353

ABSTRACT

Hypertension and diabetes co-exist frequently. Therefore, salt intake behavior, a risk factor of hypertension, in diabetic patients plays an important role in determining their cardiovascular outcome. The purpose of this study was to assess the knowledge and behaviors of health risks associated with a salt intake in adults with type 2 diabetes. This cross-sectional study was conducted among the type 2 diabetic in-patients of Bangladesh Institute of Health Sciences General Hospital, Dhaka, Bangladesh from October to December 2016. Data were collected from 131 respondents through interview using WHO STEPS module of salt with adaptation to local context like on amount of added salt while taking meal. Information on blood pressure, body mass index and relevant co-morbidities were also collected. About half of the respondents were women (56.5%). Mean age of the respondents was 54.3±14.4 years. More than six in 10 of them (62.6%) took added salt while taking meal; and 40.5% took processed foods with high salt. The mean amount of added salt intake among the users was 4.4±1.6gm per day having no significant difference between men and women. Though 47.3% of the respondents believed that lowering salt in meal is very important and 77.9% of them believed that excess salt or salty sauce can cause health problems. Salt intake behavior is poor in patients with type 2 diabetes even having regular contacts with doctors and other health professionals. Appropriate measures can be taken to increase awareness, change their attitude and behavior regarding salt consumption.


Subject(s)
Diabetes Mellitus, Type 2/diagnosis , Health Behavior , Health Knowledge, Attitudes, Practice/ethnology , Sodium Chloride, Dietary/adverse effects , Adult , Aged , Bangladesh/epidemiology , Cross-Sectional Studies , Diabetes Mellitus, Type 2/epidemiology , Feeding Behavior , Female , Humans , Male , Middle Aged , Sodium Chloride, Dietary/administration & dosage
4.
Mymensingh Med J ; 27(4): 813-819, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30487499

ABSTRACT

Diastolic function usually declines before systolic function, and this precedes clinical signs in patients with acute coronary syndrome. Therefore, diagnosis of diastolic dysfunction is very important for early diagnosis, follow-up, treatment, and prognostic evaluation in heart failure with preserved ejection fraction (HFpEF) patients. The main objective of the study was to find out association between prolonged QTc dispersion and left ventricular diastolic dysfunction in Non ST Segment Elevation Myocardial Infarction (NSTEMI) patients in HFpEF. This cross sectional analytical study was conducted in the Department of Cardiology and 60 patients were included as study population from August 2015 to July 2016. Then the study population was divided into two groups, each group consisted of 30 patients. NSTEMI patients with prolonged QTc dispersion treated as Group I and NSTEMI patients with normal QTc dispersion treated as Group II. The study shows 20.0% vs. 26.6% patients had detected as Grade I in Group I and Group II respectively with statistically insignificant association (p=0.16). On the contrary, 30.0% vs. 13.4% patients had detected as Grade II in Group I and Group II respectively with statistically significant association (p=0.001). Again, 40.0% vs. 10.0% patients had detected as Grade III in Group I and Group II respectively with statistically significant association (p=0.001). QTc dispersion was found sequentially significant increased (p=0.007) among 3 grades of LVDD (63.6±4.9 vs. 79.4±8.6 vs. 98.2±28.8). QTc dispersion in surface ECG which is a cheap, non-invasive, easily available tool can help us predicting left ventricular diastolic dysfunction in patients with NSTEMI.


Subject(s)
Non-ST Elevated Myocardial Infarction , Ventricular Dysfunction, Left , Cross-Sectional Studies , Electrocardiography , Heart Ventricles , Humans , Non-ST Elevated Myocardial Infarction/complications , Stroke Volume , Ventricular Dysfunction, Left/etiology
5.
Mymensingh Med J ; 26(4): 756-761, 2017 Oct.
Article in English | MEDLINE | ID: mdl-29208862

ABSTRACT

Pituitary adenoma is the third most common primary intracranial neoplasm involving the adult population with clinical features due to excess or deficient hormone secretion or due to its mass effect. Debate about the diagnostic accuracy, sensitivity and specificity of MRI imaging in detecting pituitary adenoma has been continuing. The study was aimed to evaluate the accuracy, sensitivity and specificity of MR imaging in detecting pituitary adenoma. This cross sectional study was conducted in the Department of Radiology and imaging, Bangabandhu Sheikh Mujib medical University (BSMMU) from July 2013 to August 2015. It was carried out in 50 pituitary adenoma cases of which, 28 male and 22 female to see the impact of MRI in the diagnosis of pituitary of adenoma. Out of 50 cases 43 cases were diagnosed by MRI, 3 were normal and 2 were pituitary apoplexy, one was immature teratoma as confirmed through histopathology. So, MRI has got major impact in the diagnosis of pituitary adenoma.


Subject(s)
Adenoma , Magnetic Resonance Imaging , Pituitary Neoplasms , Adenoma/diagnostic imaging , Adult , Cross-Sectional Studies , Female , Humans , Male , Pituitary Apoplexy/diagnostic imaging , Pituitary Neoplasms/diagnostic imaging
6.
Mymensingh Med J ; 26(3): 574-578, 2017 07.
Article in English | MEDLINE | ID: mdl-28919612

ABSTRACT

Determination of age is one of the most important and vital demand in legal affairs, court and young sports, especially from 7-21 years. There is no established age determination table in our county. So we are dependent upon Galstaun, Bashu & Bashu and other European tables, which sometimes provide misinterpretation and variation of opinion. We should have our own table suitable for our nation. So, this prospective study was carried out in the Department of Radiology and Imaging of Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from July 2010 to June 2014 (five years) to assess the general skeletal maturity. Three hundred boys and girls of known date of birth were selected on random basis from Dhaka. Ages were limited within 7 to 21 year. Every 20 person for each age group, of them 10 were male and 10 were female. To observe the bony maturity, radiographs were taken at the end of their age belongs to. Thus a growth table is to be prepared for further evaluation.


Subject(s)
Age Determination by Skeleton , Adolescent , Age Determination by Skeleton/methods , Bangladesh , Child , Female , Humans , Male , Prospective Studies , Radiography , Young Adult
7.
Mymensingh Med J ; 26(3): 628-634, 2017 07.
Article in English | MEDLINE | ID: mdl-28919620

ABSTRACT

In spite of the global decline in its incidence and mortality, gastric carcinoma still remains a major cause of death due to cancer. Early detection of gastric carcinoma is expected to reduce mortality rates. The applications of measuring of pepsinogen I and pepsinogen II are useful in screening of gastric carcinoma. This cross sectional comparative study was done to find out the correlation of histopathological pattern of gastric carcinoma with serum pepsinogen I & II ratio in the Department of Pathology, Sylhet MAG Osmani Medical College, Sylhet, Bangladesh from January 2010 to December 2010. For these purpose 40 patients with gastric carcinoma, endoscopically visible and histopathologically proved malignant lesions were enrolled as case group. Forty subjects with normal upper GI endoscopy were taken as control. Five ml of venous blood was taken from both case and control subjects to determine serum pepsinogen I and pepsinogen II level by ELISA method, subsequently pepsinogen I and II ratio was calculated. In this study different cut off values of serum pepsinogen I and II ratio was determined and the sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 70.0%, 97.5% 96.6% 76.5% and 83.8% respectively, at cut off value of 6. Which is the most suitable cut off point of serum pepsinogen I and II ratio for gastric cancer screening.


Subject(s)
Pepsinogen A , Pepsinogen C , Stomach Neoplasms , Bangladesh , Cross-Sectional Studies , Early Detection of Cancer , Humans , Pepsinogen A/blood , Pepsinogen C/blood , Stomach Neoplasms/blood , Stomach Neoplasms/diagnosis
8.
Mymensingh Med J ; 26(1): 104-108, 2017 01.
Article in English | MEDLINE | ID: mdl-28260763

ABSTRACT

Tuberculosis is a very common disease in our country. This retrospective histopathological study was designed to assess the distribution of extra-pulmonary tuberculosis (EPTB) in various organs through examination of biopsy specimens. A total of 216 specimens were diagnosed as tubercular lesion by histopathological evaluation in the Department of pathology, Community Based Medical College and a private laboratory during the period from January 2014 to December 2014. Mean age of the case was 32 years. Majority of the cases were female (126 out of 216). Lymph nodes were the most common site of EPTB (62.96%) followed by skin and subcutaneous tissue (17.59%), intestine (11.11%), breast (2.77%), female genital tract (2.31%), male genital tract (1.38%), bone and joint (1.85%). Out of 136 cases of tubercular lymphadenitis, 96(70.58%) were cervical, 18(13.23%) were axillary, 12(3.82%) were mesenteric and 10(7.35%) were inguinal. This study reveals, in our locality, EPTB is very common in adulthood with female preponderance. Cervical lymph node is very common sites for EPTB.


Subject(s)
Lymphadenitis , Tuberculosis, Lymph Node , Tuberculosis , Adult , Female , Humans , Lymph Nodes , Male , Retrospective Studies , Tuberculosis/diagnosis , Tuberculosis/pathology , Tuberculosis, Lymph Node/diagnosis , Tuberculosis, Lymph Node/pathology
9.
Mymensingh Med J ; 24(3): 516-20, 2015 Jul.
Article in English | MEDLINE | ID: mdl-26329949

ABSTRACT

Salivary gland tumors are relatively infrequent and account for less than 2% of all human tumors. This study was conducted to see the prevalence of patterns of non neoplastic and neoplastic lesions of salivary glands in greater Mymensingh. It was a retrospective study carried out in the department of Pathology, Community Based Medical College Bangladesh from January 2010 to December 2012. Heamatoxylin and eosin stained sections were studied in all cases. Total 98 cases of salivary gland lesions were retrieved and evaluated. Out of them 55 cases were female and 43 were male. Mean age of the cases were 42 years. Among the salivary gland lesions non-neoplastic lesions 24.48% and neoplastic lesions 75.51%. Among neoplastic lesions benign tumor comprises 91.89% and malignant tumor comprises 8.10%.


Subject(s)
Salivary Gland Diseases/epidemiology , Adenocarcinoma/epidemiology , Adenocarcinoma/etiology , Adenocarcinoma/pathology , Adenoma, Pleomorphic/epidemiology , Adenoma, Pleomorphic/etiology , Adenoma, Pleomorphic/pathology , Adolescent , Adult , Aged , Bangladesh/epidemiology , Carcinoma, Mucoepidermoid/epidemiology , Carcinoma, Mucoepidermoid/etiology , Carcinoma, Mucoepidermoid/pathology , Child , Female , Humans , Male , Middle Aged , Prevalence , Retrospective Studies , Salivary Gland Diseases/etiology , Salivary Gland Diseases/pathology , Salivary Gland Neoplasms/epidemiology , Salivary Gland Neoplasms/etiology , Salivary Gland Neoplasms/pathology , Tertiary Care Centers , Young Adult
10.
Mymensingh Med J ; 23(3): 441-8, 2014 Jul.
Article in English | MEDLINE | ID: mdl-25178594

ABSTRACT

An intervention study was carried out in the department of paediatrics of Mymensingh Medical College Hospital, Mymensingh to compare the clinical efficacy of Azithromycin in the treatment of childhood typhoid fever with that of cefixime for a period of one year from January 2011 to December 2011. A total of 60 cases of typhoid fever were enrolled in to a randomized clinical trial and was divided into two groups. The inclusion criteria of the cases were: Documented fever for more than 4 days plus two or more of the following clinical features: toxic physical appearance, intestinal complaints, coated tongue, ceacal gurgling, hepatomegaly and splenomegaly, diarrhoea and constipation plus positive Widal test and/or blood culture positivity. Patients who had complication like GIT heamorrhage; intestinal perforaion and/or shock were excluded from the study. Data were collected in a structured questionnaire. Azithromycin was given at a dose of 10mg/kg/day for a period of 07 days Cefixime was given at a dose of 20mg/kg/day in two divided dose for 14 days. The mean time of defervesence was 4.05+1.14 days with azithromycin and 3.41+0.95 with cefixime respectively. The minimum defervesence time was 02 days and maximum defervesence time was 07 days. Clinical cure rate was 87% in azithromycin group and 93% in cefixime group. No serious adverse effect was noted related to azithromycin and cefixime therapy except nausea, vomiting, diarrhoea and jaundice. It was found that azithromycin is almost as effective as cefixime in the treatment of typhoid fever.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Azithromycin/therapeutic use , Cefixime/therapeutic use , Typhoid Fever/drug therapy , Child , Child, Preschool , Female , Humans , Male
11.
Mymensingh Med J ; 22(2): 267-74, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23715347

ABSTRACT

The school age is a dynamic period of growth and development. During this period physical, mental, social development of child takes place. The purpose of the study is to observe the nutritional status among the school aged children and to compare the urban and rural children. It is a descriptive cross sectional study. Data were collected from 600 children of primary school in Mymensingh district for a period of one year from October 2009 to September 2010. Among the primary school children in Mymensingh, Bangladesh 15.1% were wasted, 22.1% were stunted, 2.3% were both stunted and wasted and 60.4% children were within normal limit. Malnutrition was more in rural area in comparison with urban area. In rural area severely underweight, moderately underweight children were 62.1%, 65.6%, and corresponding result in urban area were 37.9%, 34.4% respectively. In rural area severely stunted, moderately stunted children were 100%, 58.6%, and in urban area they were 0%, 41.4% respectively. Again severely wasted and moderately wasted, children were 62.5%, 59.5% in rural area and 37.5%, 40.5% in urban area respectively. Malnutrition among girls were more then the boys.


Subject(s)
Nutrition Disorders/epidemiology , Nutritional Status , Bangladesh/epidemiology , Child , Cross-Sectional Studies , Female , Humans , Male , Rural Population , Surveys and Questionnaires , Urban Population
12.
Mymensingh Med J ; 21(4): 767-71, 2012 Oct.
Article in English | MEDLINE | ID: mdl-23134934

ABSTRACT

Smooth muscle tumors presenting as mediastinal soft tissue masses are rare and are often mistaken for other neoplasms. Benign tumors of the esophagus account for fewer than 1% of all esophageal tumors, the most common of which are leiomyomas. They are frequently located in the lower third of the esophagus. We report two cases of esophageal leiomyoma in the thoracic esophagus which were firstly presented as huge mediastinal mass with intermittent dysphagia and radiologically flecks of calcification.


Subject(s)
Esophageal Neoplasms/diagnosis , Leiomyoma/diagnosis , Adult , Esophageal Neoplasms/pathology , Female , Humans , Leiomyoma/pathology , Mediastinal Neoplasms/diagnosis
13.
Mymensingh Med J ; 20(3): 446-9, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21804510

ABSTRACT

Because of hypoxemia, different organ systems of the body are affected in perinatal asphyxia. In this study, the functional status of liver of the asphyxiated babies was assessed through estimation of liver enzymes to see any correlation existing between enzyme changes and severity of perinatal asphyxia. A total of 70 full-term asphyxiated newborns (study group) were studied during January'2008 to December'2008 in the department of Paediatrics, Mymensingh Medical College Hospital. After enrollment these babies were grouped according to Sarnat & Sarnat stages of Hypoxic-ischemic encephalopathy (HIE) as stage I, II & III. Babies who are small for gestational age, having severe jaundice, sepsis or congenital anomalies of the hepatobiliary system were excluded from the study. Another 50 healthy newborns were also studied as control group. Venous blood was analyzed between 2nd and 5th day of life to estimate serum AST, ALT & alkaline phosphatase (ALP). Unpaired student's 't' test and Spearman's rank correlation was used for data analysis and P value of <0.05 were considered significant. Mean AST, ALT and ALP of the asphyxiated babies were 76.27±37.44, 82.16±48.08 & 369.59±123.05 U/L and that of normal babies were 23.46±8.45, 26.54±7.76 & 208.20±46.95 U/L respectively and these rise were statistically significant (p<0.001). The levels of transaminases and ALP were positively correlated with the severity of asphyxia and these correlations were also statistically significant (p<0.001). So, this study concludes that AST, ALT & ALP significantly elevated in perinatal asphyxia and this elevation was proportional to the severity of hypoxia.


Subject(s)
Alanine Transaminase/metabolism , Alkaline Phosphatase/metabolism , Aspartate Aminotransferases/metabolism , Asphyxia Neonatorum/enzymology , Hypoxia/metabolism , Liver/enzymology , Asphyxia Neonatorum/complications , Humans , Hypoxia/etiology , Infant, Newborn , Severity of Illness Index
14.
Mymensingh Med J ; 20(3): 450-8, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21804511

ABSTRACT

A randomized clinical trial was conducted to asses the effects of dexamethasone on brain oedema following acute ischemic stroke in the departments of Medicine of different hospitals from July, 2003 to December, 2006. A total of 60 patients were included in the study. They were divided into two groups keeping the similarity regarding the age, sex and severity of the stroke between two groups. There were 30 patients in experimental group and 30 in control group. The level of consciousness was compared by Glasgow Coma Scale (GCS) on 3rd, 7th and 10th day of intervention and improvement was found in both the groups, but the improvement of level of consciousness was statistically significant in Dexamethasone treated group. The volume of hypodense area did not differ significantly in two groups in CT scans before and after treatment (p=0.74). The study results demonstrate that Dexamethasone improves the level of consciousness in acute ischemic stroke associated with brain oedema but did not reduce volume of hypodense area.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Brain Edema/drug therapy , Brain Ischemia/complications , Consciousness/drug effects , Dexamethasone/therapeutic use , Stroke/complications , Adult , Aged , Brain Edema/diagnostic imaging , Brain Edema/etiology , Double-Blind Method , Female , Humans , Male , Middle Aged , Radiography , Treatment Outcome
15.
Mymensingh Med J ; 19(3): 335-9, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20639822

ABSTRACT

Kala-azar is one of the major public health problem in Bangladesh. But the diagnosis of the problem often is difficult, unusual and time consuming, a simple, noninvasive, easy to perform, reliable and rapid diagnostic test has been a long-felt need of the clinicians. Therefore, the present study was conducted to see the sensitivity and specificity of Latex Agglutination test (KAtex) to detect leishmanial antigen from urine of kala-azar cases. The study was carried out in the department of Paediatrics, Mymensingh Medical College and Hospital, Bangladesh during July to December, 2008. A total of 100 urine samples were collected of which 50 were confirmed kala-azar cases and 50 were age and sex matched controls. Out of 50 kala-azar cases 47 showed positive result of KAtex. The test was also positive in 01 out of 30 healthy controls. None of the febrile controls was positive by KAtex. The sensitivity, specificity, positive predictive value and negative predictive value of the test using presence of LD bodies in splenic and/or bone marrow aspirate as gold standard were 94%, 98%, 97.91% and 94.23% respectively. KAtex is simple, noninvasive, easy to perform, rapid and reliable test for diagnosing kala-azar in endemic area and useful for small, less equipped laboratories as well as for the laboratories with better facilities.


Subject(s)
Latex Fixation Tests , Leishmaniasis, Visceral/diagnosis , Adolescent , Case-Control Studies , Child , Child, Preschool , Cross-Sectional Studies , Early Diagnosis , Female , Humans , Infant , Leishmaniasis, Visceral/urine , Male , Predictive Value of Tests , Sensitivity and Specificity
16.
Mymensingh Med J ; 18(1): 13-7, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19182742

ABSTRACT

A recently developed DOT enzyme immunoassay known as "Typhidot" for detecting IgM antibody against 50 KDa OMP antigen of Salmonella typhi, was evaluated on 100 clinically suspected typhoid fever cases and 40 age-sex matched controls, in the Department of Microbiology, Mymensingh Medical College during, the period from June 2006 to July 2007. Blood culture, Widal test, and DOT EIA for IgM test were performed in all patients. Among 100 clinically suspected typhoid fever cases, 35 were subsequently confirmed on the basis of positive blood culture for S. typhi and/or significant rising titre of Widal test. The DOT EIA IgM test could produce results within 1 hour. The result of the DOT EIA IgM test showed a good diagnostic value for typhoid fever. The sensitivity, specificity, positive and negative predictive value of the test was found as 91.42%, 90.00%, 88.88% and 92.30% respectively. On the other hand corresponding values for Widal test were of 42.85%, 85.00%, 71.42% and 62.96% respectively. Thus, The DOT EIA IgM seems to be a practical alternative to Widal test for early diagnosis of typhoid fever.


Subject(s)
Agglutination Tests , Immunoenzyme Techniques , Immunoglobulin M/blood , Salmonella typhi/isolation & purification , Typhoid Fever/diagnosis , Case-Control Studies , Cross-Sectional Studies , Humans , Immunoblotting , Predictive Value of Tests , Salmonella typhi/immunology , Sensitivity and Specificity , Time Factors
17.
J Biosci Bioeng ; 92(5): 423-8, 2001.
Article in English | MEDLINE | ID: mdl-16233122

ABSTRACT

Thermotoga maritima MSB8 possesses two xylanase genes, xynA and xynB. The xynB gene was isolated from the genomic DNA of T. maritima, cloned, and expressed in Escherichia coli. XynB was purified to homogeneity by heat treatment, affinity chromatography and ion-exchange column chromatography. The purified enzyme produced a single band upon SDS-PAGE corresponding to a molecular mass of 42 kDa. At 70 degrees C, the enzyme was stable between pH 5.0 and pH 11.4, and it was stable at temperatures of up to 100 degrees C from pH 7.0 to pH 8.5. At 50 degrees C, XynB displayed an optimum pH of 6.14 and at this pH the temperature for optimal enzyme activity was 90 degrees C. XynB exhibited broad substrate specificity and was highly active towards p-nitrophenyl-beta-D-xylobioside with K(m) and k(cat) values of 0.0077 mM and 5.5 s(-1), respectively, at 30 degrees C. It was also active towards p-nitrophenyl-beta-D-xyloside. The initial product of the cleavage of p-nitrophenyl-beta-D-xyloside was xylobiose, indicating that the major reaction in the cleavage was transglycosylation, not hydrolysis.

18.
J Bacteriol ; 178(19): 5732-40, 1996 Oct.
Article in English | MEDLINE | ID: mdl-8824619

ABSTRACT

The Clostridium thermocellum F1 celJ gene, encoding endoglucanase J (CelJ), consists of an open reading frame (ORF) of 4,803 nucleotides and encodes a protein of 1,601 amino acids with a molecular weight of 178,055. The ORF was confirmed as celJ by comparison with the N-terminal sequence of a truncated CelJ derivative. CelJ is a modular enzyme composed of N-terminal signal peptide and six domains in the following order: an S-layer homology domain, a domain of unknown function (UD-1), a subfamily E1 endoglucanase domain, a family J endoglucanase domain, a docking domain, and another domain of unknown function (UD-2). UD-1 has no significant similarity to UD-2. CelJ hydrolyzed carboxymethylcellulose and xylan, and xylanase activity was ascribed to the family J domain. Antiserum raised against the truncated CelJ cross-reacted with proteins contained in the cellulosome of C. thermocellum F1. These results strongly suggest that CelJ is equivalent to S2, which was identified as the largest catalytic component in the cellulosome of C. thermocellum YS. A second but incomplete ORF encoding an enzyme classified in subfamily E2 endoglucanase, was located downstream of celJ.


Subject(s)
Bacterial Proteins/genetics , Cellulase/genetics , Clostridium/genetics , Genes, Bacterial , Multienzyme Complexes/genetics , Amino Acid Sequence , Bacterial Proteins/biosynthesis , Base Sequence , Catalysis , Cloning, Molecular , Clostridium/enzymology , Gene Expression , Molecular Sequence Data , Multienzyme Complexes/biosynthesis , Restriction Mapping , Sequence Analysis, DNA , Sequence Homology, Amino Acid
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