Risk Factors of Patients with Postpartum Acute Kidney Injury: An Observational Study.

Postpartum acute kidney injury (AKI) is a condition characterized by a sudden and rapid decline in kidney function that occurs shortly after childbirth. Several risk factors may be associated with postpartum acute kidney injury (AKI). Understanding the possible risk factors is essential for timely intervention and improved maternal healthcare. The aim of the study was to assess the risk factors of postpartum acute kidney injury patients. This prospective observational study took place at Mymensingh Medical College Hospital, from March 2020 to April 2021. It was carried out in the Departments of Nephrology and Departments of Obstetrics & Gynecology, where 153 postpartum acute kidney injury (AKI) patients were enrolled through purposive sampling. The study collected data on patient demographics, etiology and presentation. Statistical analysis was conducted using SPSS (Statistical Package for the Social Sciences) version 26.0, with a significance threshold set at p<0.05 for all tests. Among participants, puerperal sepsis (77.8%) and toxemia of pregnancy (58.8%) were prevalent risk factors. Intrauterine death was rare (1.3%). Other risk factors such as postpartum hemorrhage 22.2%, HELLP syndrome 11.1%, and antepartum hemorrhage 15.0% were found. A statistically significant difference in postpartum hemorrhage prevalence (p=0.038) was noted between hemodialysis and non-hemodialysis patients. Puerperal sepsis is the most common risk factor for postpartum acute kidney injury, closely followed by toxemia of pregnancy. Intrauterine death is rare, while postpartum hemorrhage significantly affects subjects, with variations noted between hemodialysis and non-hemodialysis patients.

Assessment of Dialysis Adequacy Using Small Solute Clearance Indices among Twice versus Thrice Weekly Maintenance Hemodialysis Patients in a Tertiary Care Hospital of Bangladesh.

This observational study was carried out in the Department of Nephrology, Mymensingh Medical College Hospital, Bangladesh from January 2020 to December 2020. A total of 179 patients were included in this study according to inclusion and exclusion criteria. Informed written consent was taken from each patient. All patients were underwent detail history taking, thorough physical examination and relevant investigations. Data collection was conducted through a structured questionnaire. Collected data were analyzed using the statistical software SPSS 23.0. Mean age ±SD of the study patients was 47.06±14.1 with a majority in age group 41-50 years. Male predominance was observed with a male: female ratio of 2.19:1 and 68.7% male patients. Level of pre-dialysis, post-dialysis urea in the study population was 123.77±26.86mg/dl, 50.27±15.70mg/dl respectively and mean ±SD of Urea Reduction Ratio (URR) in hemodialysis (target >65.0%) was 67.2±1.9. Most of the 8 hours (two times) per week hemolysis patients could not achieve the target value of dialysis adequacy parameters. On the other hand, maximum people in 12 hours (three times) per week hemodialysis group achieved the target value of dialysis adequacy parameters. It is important to calculate Kt/V or URR and individualize the dialysis doses for each patient.

Association of Serum Vitamin D Concentration with the Severity of Patients with Atopic Dermatitis.

Atopic Dermatitis (AD) is a chronically relapsing, highly pruritic, allergic inflammatory skin disease with significant cost and morbidity to the patients and their families. The underlying cause of AD has not been understood, however some studies have shown initial epidermal barrier defect with subsequent immune activation as the underlying mechanism of AD. Vitamin D is now recognized as an immunomodulator. The role played by vitamin D in atopic dermatitis is controversial and has been the focus of many studies. The aim of the study was to measure serum vitamin D in the form of 25-hydroxy vitamin D in patients with AD and to correlate them with disease severity. This cross-sectional study included 41 patients (25 males and 16 females) of any age with the clinical diagnosis of AD seen in Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from September 2015 to February 2017. Disease severity was determined using Scoring Atopic Dermatitis (SCORAD) index and the patients were divided into three groups: mild (SCORAD index <25), moderate (25-50) and severe (>50). Serum vitamin D levels were classified as sufficient (≥30ng/mL), insufficient (21-29ng/mL) and deficient (≤20ng/mL). Statistical analysis was performed using analysis of variance (ANOVA) and Pearson's correlation coefficient test. P value of <0.05 was considered as statistically significant. Among 41 patients 33 represent infantile and childhood AD and only 8 represent adolescent and adult AD. According to SCORAD index, 12 patients had mild, 20 had moderate and 9 had severe Atopic dermatitis. Levels of 25-hydroxyvitamin D were deficient or insufficient in 75.6% of patients and normal in 24.4% patients. There was no significant association between serum level of vitamin D and the severity of AD (r=-0.173). The mean±SD serum vitamin D level in mild AD (25.7±8.1) was higher compared with those with moderate (23.9±8.8) or severe (19.5±8.3) AD. But the result was not statistically significant (p=0.249). Variables such as sex, age, skin prototype, season and food allergy were not significantly associated with vitamin D levels. The results from this study suggesting that millions of children living in Bangladesh may have suboptimal levels of vitamin D, which should be a matter of public health concern. But these deficient results are not significantly related to AD severity. Thus, the study provides epidemiological evidence against the association of vitamin D status with atopic dermatitis for the first time in Bangladesh.

Clinical Profiles and Outcomes of Cytomegalovirus Positive Renal Transplant Patients in Early Post-Transplant Period.

Cytomegalovirus infection can cause increased mortality and morbidity in renal transplant recipient. The purpose of the present study was to observe the clinical profiles and outcomes of Cytomegalovirus positive renal transplant patients in early post-transplant period. This prospective cohort study was conducted in the Department of Nephrology at Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from September 2016 to August 2017. Adult patients who had undergone renal transplantation were selected as study population. CMV serology (CMV IgM and CMV IgG) of both donor and recipient were detected before renal transplantation. Cytomegalovirus viral DNA was extracted from both serum by using a commercially available DNA extraction kit and PCR was done by the StepOne™ PCR machine using real time PCR kit in all patient during the early post-transplant period. During this period, sign symptoms of patients with cytomegalovirus infection as well as clinical outcomes were also noted. Total number of 32 patients was included in this study with the mean age of 31.15±11.56 years. Cytomegalovirus was found positive in 11(34.4%) patients and negative in 21(65.6%) patients. Anorexia was the most common presentation which was found in 81.8% cases followed by renal impairment, fever, diarrhea, cough and weight loss which were present in 6(54.5%), 3(27.3%), 2(18.2%), 2(18.2%) and 2(18.2%) cases respectively. The outcomes of cytomegalovirus positive patients in first 6 months after renal transplantation revealed 25.0% patients had cytomegalovirus infection; 6.2% patients had cytomegalovirus disease and 6.2% patients were died. However, 9.4% patients had co-infection in the form of UTI and 6.2% patients had re activation of hepatitis C infection associated with cytomegalovirus infection. Cytomegalovirus was found positive in approximately one third of renal transplant recipients in early post-transplant period. Careful clinical evaluation and appropriate laboratory parameters should be looked over for timely diagnosis and management of these cases.

SARS-CoV-2 Infection after Vaccination: A Comparative Profile between Dose 1 and Dose 2.

Since the initial shipment of vaccination campaign against SARS-CoV-2 infection, it was a major concern all over the world regarding appropriate gapping between the first and second dose and also the necessity of booster dose after being vaccinated with the second dose. This cross-sectional type of comparative study was conducted at Kuwait Bangladesh Friendship Government Hospital, from the period of March 01 2021 to August 31 2021, on 148 hospitalized patients who were vaccinated with Astra Zeneca. They were divided into two groups on the background of 1st dose and 2nd dose. Collected data were entered into SPSS-26 version and after data cleaning, descriptive analysis was done with frequency distribution. To find out the significant difference between the two groups considering clinico-demographic information, disease severity, and duration of the last dose of vaccine; the Pearson Chi-square test was done with a significance level ≤0.05. The patients from both groups were mostly male and above 60 years. There were no significant age or sex variations between the two groups. SARS-CoV-2 infection was common after 38 days of dose 1 and after 63 days of dose 2. Fever, cough, running nose, shortness of breath, fatigue, nausea, vomiting, lower oxygen saturation, radiological involvement were comparatively more in patients who got only a single dose. Mild pneumonia (70.7%) was the commonest presentation in both doses of vaccinated patients and single dose vaccinated patients mostly (45.5%) presented with severe pneumonia. Elderly clinically risks group patients were mostly hospitalized with infection after 1 month of the 1st dose and on the other hand after 2 months of completing the 2nd dose. Symptomatic infection and disease severity were more in 1st dose vaccine recipients in comparison to 2nd dose.

Pattern of Glomerular Disease in a Tertiary Care Hospital of Bangladesh.

Glomerular disease is one of the most important causes of chronic kidney disease in developing countries like Bangladesh as well as the whole world. The pattern of glomerular disease varies in different countries and can have different clinical presentations. The aim of the study was to analyze the clinical profile and to determine the histological pattern of glomerular diseases in a large tertiary care hospital in Bangladesh. All kidney biopsies performed in Mymensingh Medical College Hospital, Bangladesh from October 2018 to March 2020 were prospectively analyzed in the study. A total of 101 patients with kidney biopsy were examined by clinical and laboratory findings and by light and immuno-fluorescence microscopy. The mean age was 30.0±14.6 years and 50(49.5%) were male and 51(50.5%) were female with a male to female ratio of 1:1. The clinical syndromes namely nephrotic syndrome, nephritic syndrome, nephrito-nephrotic presentation, RPGN like presentation, macroscopic haematuria and asymptomatic urine abnormality were present in 31.7%, 34.5%, 22.8%, 11.9%, 19.8% and 10.9% patients respectively. The most common histological varieties found in the study were mesangial proliferative glomerulonephritis (MesPGN) (18.8%) and focal segmental glomerulosclerosis (FSGS) (18.8%). Other histopathological pattern among the studied subjects revealed minimal change disease (MCD) in 5.9%, membranous nephropathy (MN) in 7.9%, membranoproliferative glomerulonephritis (MPGN) in 16.8%, IgA nephropathy in 5%, IgM nephropathy in 2%, IgG nephropathy in 2%, diffuse proliferative glomerulonephritis (DPGN) in 1%, focal proliferative glomerulo-nephritis (FPGN) in 3%, crescentic GN in 3%, lupus nephritis (LN) in 13.9%, amyloidosis in 1% and fibrillary glomerulopathy in 1% patient. The pattern of glomerular disease found in this study was similar to other studies performed in Bangladesh with a little variation. It may guide the future researchers to establish a national kidney biopsy registry in Bangladesh.

A Middle-Aged Woman Presented with Catastrophic Anti-phospholipid Syndrome in Nephrology Department of BSMMU.

A life threatening rare condition called catastrophic antiphospholipid syndrome leading to multiple organ failure is characterized by vascular thrombosis in the presence of anti-phospholipid antibody which often appear as a medical emergency. Antiphospholipid antibody syndrome whether primary or secondary cause thromboembolic manifestation resulting recurrent fetal loss, but catastrophic antiphospholipid antibody syndrome may not present in such a way, rather multi-system involvement occurs within a short period of time. We would like to present a case of 50 years old female who is hypertensive, non-diabetic, a known case of hypothyroidism for two years, who was admitted to our hospital after developing fever for 7 days and black discoloration of lateral three fingers of left hand for short period of time. The patient had no medical problems and had been in her usual state of health until 7 days before admission. Patient is anaemic and found to have severe renal failure. She was found high titer antiphospholipid antibody both IgM and IgG positive and anti-cardiolipin antibody positive. Her routine investigations revealed very high neutrophilic leukocytosis, high acute phase reactant, urinary findings revealed no active sediment; we thought that our patient might have sepsis that may trigger catastrophic antiphospholipid syndrome. Multi-disciplinary consultation gave us valuable opinion. Considering her septicemia, she was given broad spectrum antibiotic. Anticoagulation was given with unfractionated heparin followed by warfarin and as an immunosuppressive protocol methylprednisolone followed by prednisolone along with pulse cyclophosphamide was given. Treatment option with plasma pheresis and monoclonal antibody was not attempted, but she was given several session of hemodialysis, within a few days her biochemical parameters improved. Severe renal failure in this patient may be explained by septicemia or thrombotic micro-angiopathy that was reversed with anti-coagulation or proper antibiotic. Amputation of three digit of left hand was done by orthopedic surgeon but unfortunately two weeks after admission the patient expired due to sudden stroke.

Correlation of eGFR By MDRD and CKD-EPI Formula with Creatinine Clearance Estimation in CKD Patients and Healthy Subjects.

This cross sectional comparative study was conducted in the Nephrology and Medicine outdoor and in-patients department of Mymensingh Medical College Hospital, Bangladesh from April 2014 to March 2015. A total of 100 patients with CKD and 100 healthy subjects were included in the study. Data were collected by interview of the patients, clinical examination and laboratory investigations using a semi-structured case record form. Among all subjects, 50.0% had no CKD and 50.0% patients had CKD: Stage 3 CKD were 8.5%, CKD Stage 4 CKD were 21.0%, CKD Stage 5 CKD were 20.5%. Serum creatinine was 4.32±3.08mg/dl in patients with CKD and 1.00±0.22mg/dl was in healthy subjects. Mean±SD of CCR/ml/min was found 17.67±11.63ml/min in patients with CKD and 79.31±13.31ml/min was found in healthy subjects. On the other hand, Mean±SD CCCR/ml/m/1.73m² was found 19.79±12.85 ml/m/1.73m² in patient with CKD and healthy subjects had 83.83±13.33 ml/m/1.73m². Urinary creatinine was 45.59±15.63 & 57.66±11.45mg/dl respectively. CKD-EPI eGFR was 22.10±15.02 & 90.61±23.27ml/m/1.73m²; MDRD eGFR was 22.15±14.18 & 89.35±26.19 ml/m/1.73m² respectively. Difference between all the variables between CKD group and healthy group was found statistically significant (p<0.001). CKD-EPIeGFR and MDRDeGFR were increased both in CKD patients and healthy subjects in respect to CCR and CCCR. There was a strong positive correlation between CCCR (ml/m/1.73m2) and CKD-EPI (ml/m/1.73m²) among all patients (r=0.934 and p<0.001) and also a positive correlation of CCCR with MDRD among all patients (r=0.913 and p<0.001). A positive correlation of CCCR was found with CKD-EPIeGFR among CKD patients (r=0.848 and p<0.001). A positive correlation of CCCR was also found with MDRDeGFR among CKD patients (r=0.841, p<0.001). There are positive correlations between CCCR and CKD/EPI among healthy subjects (r=0.616 and p<0.05) and between CCCR with MDRD among healthy subjects (r=0.568 and p<0.05). Various formulae were used to calculate GFR on the basis of serum creatinine levels. The Overall correlation of population (healthy and CKD patients) between CCCR and CKD EPI and MDRD formula was (r=0.93 and 0.91) respectively, among CKD patients it was (r=0.848 and r=0.841) in healthy subjects it was (r=0.616 and r=0.568) respectively. CKD EPI eGFR and MDRD eGFR formula had fairly good correlation with conventional 24 hours creatinine clearance in both CKD patient and healthy subjects, there was even more strong correlation especially in CKD patients. The performance of CKD-EPI equation is better than MDRD equation to estimate the eGFR in both CKD patients and healthy subjects.

Prevalence of Subclinical Hypothyroidism in Hospitalized Pre-dialysis Patients with Chronic Kidney Disease.

Among general population sub-clinical primary hypothyroidism is common. The cross sectional descriptive type of observational study was conducted in medicine and allied wards in Mymensingh Medical College Hospital, Mymensingh, Bangladesh from January 2010 to December 2010; among 230 purposively selected hospitalized pre-dialysis patients with chronic kidney disease. The purpose of the study was to find out the prevalence of sub-clinical hypothyroidism in hospitalized pre-dialysis patients with chronic kidney disease. Data were collected from the patients using a case record form by face to face interview, clinical examination and laboratory investigations. The collected data were entered into SPSS version 20.0 and analyzed accordingly. Mean age of the patients was 47.2 years with a SD of ±2.05 years. Maximum patients were male with a male female ratio of 5:1. A significant number of patients were smoker- 11.8% of sub-clinical hypothyroidism group and 13.6% of euthyroid group. Among the patients 40 (17.40%) had sub-clinical hypothyroidism while the majority 190 (82.60%) did not have it. Estimated prevalence of sub-clinical hypothyroidism in hospitalized pre-dialysis patients with chronic kidney disease was 17.40%. Co-morbidities found in the patients were hypertension, diabetes mellitus, chronic glomerulonephritis and obstructive uropathy. All the patients (40, 100.0%) with sub-clinical hypothyroidism were hypertensive. On the other hand, 184 (97.1%) patients without sub-clinical hypothyroidism were hypertensive. Presence of co-morbidities in patients with sub-clinical hypothyroidism did not differ significantly (p>0.05) from patients without sub-clinical hypothyroidism. Patients in group with sub-clinical hypothyroidism were more over weight in comparison to patients without sub-clinical hypothyroidism (p<0.05). Biochemical parameters of patients with sub-clinical hypothyroidism differed significantly (p<0.05) from those of patients without sub-clinical hypothyroidism. There was no significant difference between urinary albumin of two groups of patients (p>0.05). Stage 4 CKD patients were more in sub-clinical hypothyroidism group in comparison to euthyroid group. As this study may not reflect the actual picture, further large scale multi-centric study is recommended to explore the real situation of sub-clinical hypothyroidism in patients with chronic kidney disease.

Comparison of Cardiac Outcome of Continuous Ambulatory Peritoneal Dialysis & Hemodialysis in CKD5 Patients with Heart Failure.

Prevalence of heart failure (HF) among end stage renal disease (ESRD) patients is high and HF remains the main cardiovascular co-morbidity at dialysis initiation. There is paucity of data comparing change of NYHA class, improvement of ejection fraction (EF) and major cardiac events in ESRD patients with concomitant heart failure on haemodialysis to those on peritoneal dialysis. The objective of the study was to compare the cardiac outcome of continuous ambulatory peritoneal dialysis (CAPD) & hemodialysis (HD) in chronic kidney disease 5 (CKD5) patients with HF. This prospective observational study was carried out from March 2018 to February 2019 in seventy CKD 5 patients with HF who opted for CAPD or HD. Seven patients dropped out during the follow-up & sixty three patients (CAPD=31; HD=32) were followed up for symptomatic assessment of cardiac status in terms of NYHA class as well as echocardiography and serum haemoglobin at baseline and at 3rd & 6th month. Major cardiovascular events like non fatal MI, non fatal stroke & death duo to cardiovascular diseases and co-morbidities were recorded during the study period. Statistical analysis was done using SPSS 22.0. Mean age was 53.33±6.38 and 54.23±10.15 years & male to female ratio was 1.81:1 and 1.46:1 in CAPD and HD groups respectively. Both NYHA class & left ventricular ejection fraction (EF) were significantly increased after six months compared to baseline in each group and significantly more increased in the CAPD group than the HD group. Left ventricular internal diameter in diastole (LVIDd) was reduced significantly after six months compared to baseline in both groups and there was no significant difference in LVIDd reduction between the CAPD and HD groups. Major cardiovascular events were found to occur more frequently in the HD group. According to NYHA functional class, echocardiographic findings and major cardiovascular events during six months, improvement of cardiac function in CKD 5 patients with HF was better on CAPD in comparison to HD.

Comparison of Serum Amylase and Lipase Levels between Predialysis and Maintenance Haemodialysis CKD Patients.

This cross sectional study was done to compare serum levels of amylase and lipase between predialysis and maintenance haemodialysis chronic kidney disease (CKD) patients and also to find out their relationship between degrees of renal impairment in Mymensingh Medical College Hospital and National Institute of Kidney Diseases and Urology, Dhaka, Bangladesh from May 2016 to April 2017. A total of 80 patients were included purposively as study subjects and made into two groups namely predialysis CKD group comprising 50 patients and other as maintenance haemodialysis group comprising of 30 patients. Among the predialysis group majority of the CKD was caused by glomerulonephritis (48%) followed by diabetes (26%), HTN (2%) and large portion undiagnosed (24%) whereas in the haemodialysis group ESRD was caused by diabetes (46%) followed by glomerulonephritis (16%), HTN (13%) and undiagnosed (23%). This study showed that mean serum amylase (158±718U/L vs. 111±41U/L) did not significantly differ between study groups except being above reference level but serum lipase (739±888U/L vs. 434±214U/L) was significantly higher in the predialysis group. There was a correlation between rising serum creatinine with serum amylase and lipase.

Renal Involvement as a Presenting Feature of Multiple Myeloma.

Renal involvement may be the presenting feature in a vast majority of patients with multiple myeloma and is one of the key for clinical manifestations of symptomatic multiple myeloma. The purpose of the study was to find out the pattern of renal involvement at the time of presentation of multiple myeloma and to explore its association with clinical, laboratory and pathologic features of these cases. This cross sectional study was conducted in the Department of Nephrology at Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from February 2016 to September 2017. Forty seven (47) patients of newly diagnosed multiple myeloma having renal involvement were included in the study. Multiple myeloma was diagnosed as per criteria proposed by the International Myeloma Working Group, 2003. Renal involvement was considered to be present when any one of proteinuria, microscopic haematuria, renal impairment or urinary tract infection (UTI) was found in the patient. Renal biopsy was done in suitable patients under ultrasound guidance after taking informed written consent. The pattern of renal involvement was detected and status of renal function was assessed and its clinical, laboratory and pathologic associations were analyzed. Data were managed by using computer based software, the Statistical Package for Social Sciences (SPSS) version 23 (IBM Corp.). Median age at presentation was 59 years with the range of 37-76 years. Female (53.2%) was slightly predominant than male (46.8%) and male to female ratio was 1:1.14. Renal impairment, microscopic haematuria, proteinuria, nephrotic range proteinuria, urinary Bence Jones protein and UTI were found in 70%, 19%, 79%, 25%, 19% and 17% of patients respectively. Median serum creatinine and proteinuria were 256µmol/l and 1.24gm/day. Hypercalcaemia and Bence Jones proteinuria were detected in 36% and 27% of patients respectively with renal impairment which were statistically significant. The precipitating factors for renal impairment were NSAIDs use (67%), hyperuricaemia (49%), hypercalcaemia (36%), dehydration (27%), UTI (18%) and no identifiable factor (3%). Dialysis was required in 15% new myeloma patient. Renal biopsy and histopathological examination revealed myeloma cast nephropathy (30%), amyloidosis (30%), glomerulosclerosis (chronic kidney disease) (20%), monoclonal immunoglobulin deposition disease (MIDD) (10%) and interstitial nephritis with fibrosis (10%). Renal involvement was a common and severe complication of multiple myeloma. Renal impairment was strongly associated with hypercalcaemia, NSAIDs use, hyperuricaemia, Bence Jones proteinuria etc.

Time-integrated thyroid dose for accidental releases from Pakistan Research Reactor-1.

The two-hourly time-integrated thyroid dose due to radio-iodines released to the atmosphere through the exhaust stack of Pakistan Research Reactor-1 (PARR-1), under accident conditions, has been calculated. A computer program, PAKRAD (which was developed under an IAEA research grant, PAK/RCA/8990), was used for the dose calculations. The sensitivity of the dose results to different exhaust flow rates and atmospheric stability classes was studied. The effect of assuming a constant activity concentration (as a function of time) within the containment air volume and an exponentially decreasing air concentration on the time-integrated dose was also studied for various flow rates (1000-50000 m3 h(-1)). The comparison indicated that the results were insensitive to the containment air exhaust rates up to or below 2000 m3 h(-1), when the prediction with the constant activity concentration assumption was compared to an exponentially decreasing activity concentration model. The results also indicated that the plume touchdown distance increases with increasing atmospheric stability.

Hydrogen ion equilibria of Cajanus cajan lectin.

Hydrogen ion titration of an affinity-purified mannose/glucose-specific lectin from Cajanus cajan pulse was carried out at 30 degrees C and ionic strength of 0.15 by a discontinuous method. The titration was reversible in the pH range 2-12.0. The numbers of different ionizable groups per 39,000 g of the lectin were 43 carboxyl groups (pKint = 3.93), 10 imidazole groups, 21 epsilon-amino groups, 12.8 phenoxyl groups (pKint = 10.0), and 5 guanidyl groups. Only seven tyrosine residues of the lectin were dissociated under native conditions. The remaining six tyrosines became available for titration upon denaturation of the lectin in 9 M urea.

Interleukin-6 in the fever and multiorgan crisis of pheochromocytoma.

A 31-y-old black man with neurofibromatosis, alcoholism and hypertension was admitted because of abdominal pain, hematemesis and cough. In the hospital he had prolonged fever and developed a multiorgan crisis. Despite thorough investigation, no infectious cause for fever was found. Urinary catecholamines and metabolites were markedly elevated. Computerized tomography revealed a mass abutting the left kidney. A diagnosis of pheochromocytoma was made, and as soon as treatment with phenoxybenzamine and propranolol was begun, the fever resolved. Serum interleukin-6 (IL-6) concentration was initially elevated, decreased after the start of adrenergic blockade, and gradually fell to an undetectable level after surgery. These observations suggest that interleukin-6 might have been causally related to the patient's fever and possibly the multiorgan crisis.

Isolation, purification and properties of cathepsin B from buffalo liver.

Cathepsin B was isolated from buffalo liver by salt fractionation, ion-exchange resin treatment, gel filtration and repeated ion-exchange chromatography using a linear salt gradient. The enzyme showed activity, against denatured hemoglobin (or ovalbumin), alpha-N-benzoyl-DL-arginine p-nitroanilide (BAPNA), and alpha-benzoyl-DL-arginine-naphthylamine (BANA). It inactivated buffalo muscle aldolase with a half life period of 21 min. The pH-activity profiles obtained for the digestion of hemoglobin (or ovalbumin) and aldolase inactivation by the enzyme were found to be different. The enzyme (mol wt 27,800 by SDS-PAGE) eluted in gel filtration with a molecular weight of 27,000 and a Stokes radius of 2.31 nm. The results showed buffalo cathepsin B to be a single-chain molecule. The N- and C-terminal amino acids of the enzyme were found to be leucine and aspartic acid, respectively. It contained 0.7% concanavalin A reactive neutral carbohydrate. The amino acid composition of buffalo cathepsin B was found to be similar to that of human liver cathepsin B. The optical properties of the buffalo enzyme were found consistent with its aromatic amino acid content. The isoionic pH of the enzyme was found to be 5.70 and the intrinsic viscosity was 3.48 ml/g whence the frictional ratio, f/f0 was computed to be 1.10 suggesting that the native enzyme conformation is compact and is globular in solution.

Effect of organic solvents on lysozyme-antilysozyme precipitin reaction.

The effect of nine organic solvents and urea on hen-eggwhite lysozyme-rabbit antilysozyme precipitin reaction was studied at a ratio of the antigen to the antibody of 1:26 by weight in 70 mM sodium phosphate buffer, pH 7.0. The organic solvents used were dioxane, acetonitrile, dimethylsulfoxide, N,N-dimethylformamide, 1-propanol, propylene glycol, trifluoroethanol, ethylene glycol and glycerol. These solvents invariably caused reduction in the amount of protein precipitated during the antigen-antibody reaction. The concentration of an organic solvent, CM, required for 50% reduction in the precipitin reaction value was determined for each organic solvent. Among the nine organic solvents, dioxane was the most potent inhibitor of the precipitin reaction. The nine organic solvents did not cause irreversible inactivation of the antigen and the antibody, and at concentrations used in this study most of them would be nondenaturing. These solvents seem to destabilize the antigen-antibody complex.

Isolation and characterization of domain I of ovoinhibitor.

Domain I of ovoinhibitor was isolated by subjecting the protein to specific chemical cleavage by cyanogen bromide followed by repeated gel filtration. The first domain of ovoinhibitor was found to be homogeneous by the criteria of gel chromatography, SDS-PAGE and PAGE. Mr values by gel filtration (10900) and SDS-PAGE (8300) were slightly higher than that computed from amino-acid sequence. This discrepancy has been attributed to the glycoprotein nature of domain I as it was found to contain 10% neutral carbohydrate and 2% sialic acid. Fluorescence spectral properties showed the presence of tryptophan in domain I. The amino-acid composition of domain I isolated in this study was in very good agreement with that computed from amino-acid sequence. Gel filtration behaviour of the first domain was consistent with a Stokes radius of 1.6 nm and a frictional ratio of 1.2 suggesting asymmetry and/or excessive hydration. Domain I was found to be a potent inhibitor of bovine trypsin but was virtually devoid of activity against chymotrypsin, elastase and proteinase K. The equilibrium association constant for domain I-trypsin complex was computed to be 6.6x10(8)M-1.

Studies on activation and inhibition of cathepsin B from buffalo liver.

Cathepsin B (EC 3.4.22.1) was purified from buffalo liver. The enzyme activity against alpha-benzoyl-DL-arginine-naphthylamine (BANA) was substantially reduced by heat (above 37 degrees C) and by nondenaturing concentrations of urea (3 M) and guanidine hydrochloride (1 M). Cathepsin B was significantly activated by 1.5 mM EDTA alone. The activation of the enzyme was further enhanced in the presence of thiol compounds, e.g., cysteine thioglycolic acid, 2,3-dimercapto-1-propenol, and dithioerythritol (DTE). The minimum concentration of the thiol compound required for optimal activation of cathepsin B was found to be lowest (0.2 mM) for DTE. The BANA hydrolyzing activity of cathepsin B was substantially reduced by Cu2+ (20-200 microM) and Ca2+ (30-250 mM) as well as by thiol blocking reagents, e.g., iodoacetate, 5,5'-dithiobis(2-nitro-benzoic acid) (DTNB), and p-hydroxymercuribenzoate (pHMB). The enzyme activity was completely abolished when the molar ratio of the reagent: cathepsin B was close to 1. The number of free sulfhydryl groups in cathepsin B was determined to be 2 by titration against DTNB and pHMB. Modification of one free thiol group of cathepsin B resulted in complete loss of BANA hydrolyzing activity.

Spectrophotometric titration of phenoxyl groups of sheep brain tubulin.

Spectrophotometric titration of phenoxyl group of sheep brain tubulin carried out in 6M guanidine hydrochloride indicated 36 tyrosine residues per dimer of tubulin. A plot of log alpha/(1-alpha) versus pH showed that 26 residues titrated with apparent pK of 10.4 and 10 residues titrated with apparent pK of 11.0. The high pK value of tyrosine could be attributed to the possibility that the molecules containing tyrosine residues were not completely utilised as these residues could have been partially shielded from the solvent. Alternatively, they could have proximal negative charges.