Pentoxifylline in severe alcoholic hepatitis: a prospective, randomised trial.

BACKGROUND: Role of corticosteroids in treatment of severe alcoholic hepatitis (SAH) is controversial. Pentoxifylline (PTX), an inhibitor of TNF, has also been shown to decrease short term mortality in SAH. Aim of this study was to evaluate the effect of PTX on short term mortality, renal and hepatic functions in patients with SAH. METHODS: Fifty patients with SAH {Maddrey's Discriminant Function (DF) > or = 32} were prospectively enrolled. Twenty five patients received PTX (400 mg orally, three times a day), and 25 received placebo for 4 weeks. Serum tumor necrosis factor (TNF) was measured in both groups. RESULTS: Baseline characteristics of the two groups were similar. At 4 weeks, mortality in PTX group was lower than that in controls {20% (5/25) versus 40% (10/25) respectively; p = 0.216; RR 0.5; 95% CI 0.19-1.25}. Renal failure was the cause of mortality in 20% (1/5) patients in PTX group, and 70% (7/10) in controls (p = 0.11). Significant reduction in urea, creatinine, DF and TNF was noted in PTX group. Reduction in TNF did not correlate with reduction in creatinine or DF. CONCLUSIONS: In patients with SAH, PTX leads to a significant improvement in renal and hepatic functions, and a trend towards decreased short term mortality.

A novel 40 kDa protein from goat mammary secretions: purification, crystallization and preliminary X-ray diffraction studies.

A novel 40 kDa protein has been purified from dry secretions of the mammary gland of goats. The first 15 N-terminal residues were sequenced and showed a sequence identity of 30% to a novel 39 kDa whey protein from bovine mammary secretions. The protein was crystallized by the microdialysis method. Protein was dissolved to a concentration of 40 mg ml(-1) in 0.025 M Tris-HCl pH 8.0 and equilibrated with the same buffer containing 19%(v/v) ethanol. The crystals belong to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 66.1, b = 107.8, c = 63.2 A and one molecule per asymmetric unit. Intensity data were collected to 2.9 A resolution, with a completeness of 95%. Since no similar model is available in the protein structure database, heavy-atom derivatives have been prepared and three-dimensional structure determination using the isomorphous replacement method is in progress.

Preparation and characterization of the N and C monoferric lobes of buffalo lactoferrin produced by proteolysis using proteinase K.

The two glycosylated N- and C-terminal lobes of buffalo lactoferrin have been produced by limited proteolysis using proteinase K. Lactoferrin is a single chain glycoprotein of molecular mass 80 kDa with two iron-binding sites and two structural lobes connected by a short peptide. Purified samples of lactoferrin, isolated from buffalo colostrum, were subjected to hydrolysis using trypsin, chymotrypsin, pepsin, subtilisin and proteinase K. The first three proteinases produced two major fragments of approximately 35 and 23 kDa together with small molecular mass peptides. Trypsin and chymotrypsin partly digested lactoferrin, while pepsin converted all the intact lactoferrin into fragments. Subtilisin hydrolysis produced fragments of 40 and 26 kDa together with low molecular mass peptides. However, SDS-PAGE of the proteinase K hydrolysis product gave a clear band at 40 kDa together with a band indicating a substantial quantity of low molecular mass peptides (< 14.4 kDa). Upon ion-exchange chromatography this product gave two major fractions, which were further purified by gel filtration and identified as the C and N lobes from their N-terminal sequences. Thus, the 40 kDa band in SDS-PAGE of the proteinase K hydrolysis product contained two fragments of equal molecular mass. On further hydrolysis with proteinase K, the N lobe was completely hydrolysed into low molecular mass peptides, while only a small fraction of the C lobe was converted into small products. This suggested that an inhibitory fragment was present in the C lobe that was released on hydrolysis to small fragments and prevented complete digestion of the C lobe by high-affinity binding to the active site of proteinase K. This fragment was isolated from the lactoferrin-proteinase K complex and its sequence determined to be Val-Ala-Gln-Gly-Gly-Ala-Ala-Gly-Leu-Ala. Circular dichroism studies indicated a high alpha-helical content in the native lactoferrin while comparatively lower helical structures were present in the N and C lobes. In addition, the iron saturations of the N and C lobes appeared to be lower than that of the native protein.

Crystal structure of a complex formed between proteolytically-generated lactoferrin fragment and proteinase K.

Lactoferrin is an iron binding glycoprotein with a molecular weight of 80 kDa. The molecule is divided into two lobes representing the N-terminal and C-terminal halves of the polypeptide chain, each containing an iron binding site. The serine proteinases such as trypsin, chymotrypsin, and pepsin hydrolyze lactoferrin into two unequal halves while proteinase K divides this protein into two equal halves. In the first step of hydrolysis by proteinase K, the C- and N-lobes, each having a molecular weight of approximately 40 kDa, are generated. In the next step, the lobes are further hydrolyzed into small molecular weight peptides. The proteinase K isolated from the hydrolyzed product does not show enzymatic activity suggesting that the enzyme is inhibited. Furthermore, the hydrolysis experiments on N-lobe and C-lobe showed that the inhibitory fragment came from the C-lobe. The purified lactoferrin fragment was found to be a decapeptide with an amino acid sequence of H2N-Val-Ala-Gln-Gly-Ala-Ala-Gly-Leu-Ala-COOH. The complex formed between proteinase K and lactoferrin fragment was crystallized by microdialysis. The crystals belonged to the monoclinic space group P2(1) with cell dimensions a = 44.4 A, b = 38.6 A, c = 79.2 A, beta = 105.8 degrees and Z = 2. The crystal structure has been determined at 2.4 A resolution. It has been refined to an R factor of 0.163 for 9044 reflections. The Lf-fragment forms several intermolecular interactions with proteinase K. The Ser-224 Ogamma and His-57 N epsilon2 move away to a distance of 3.68 A in the complex. In the crystal structure, Gln-3I (I indicates inhibitor i.e., lactoferrin fragment) is involved in a direct intermolecular interaction with a symmetry related proteinase K molecule through a strong hydrogen bond with Asp-254. The mode of intermolecular interactions in the complex conformational features of the enzyme and placement of the fragment with respect to the enzyme resemble with the molecular complex of proteinase K with its natural inhibitor PKI3 from wheat.

Crystallization and preliminary X-ray diffraction studies of the proteolytically engineered C-terminal half of buffalo lactoferrin in its iron-saturated form.

The glycosylated functional monoferric C-terminal half (C lobe) (M(r) approximately 40 kDa) of buffalo lactoferrin has been produced by limited proteolysis using proteinase K. The iron-saturated C lobe has been crystallized by microdialysis. The crystals belong to the monoclinic system, space group P2(1) with unit-cell dimensions of a = 44.4, b = 152.3, c= 38.8 A and beta = 105.5 degrees. There is one protein molecule of 40 kDa in the asymmetric unit. A data set at 2.8 A has been collected on an imaging-plate scanner.

Purification, crystallization and preliminary X-ray crystallographic analysis of lactoperoxidase from buffalo milk.

The lactoperoxidase was prepared from buffalo milk and purified using CM-Sephadex C-50 and Sephadex G-100. The activity of the enzyme was measured using 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt as a chromogenic substrate at pH 6.0. The purified protein was crystallized from 0.01 M sodium phosphate buffer (pH 8.0) with 10%(v/v) ethanol by the sitting-drop vapour-diffusion method. The green-coloured plate-like crystals are orthorhombic in space group P2(1)2(1)2(1) with unit-cell dimensions a = 116.9, b = 103.2 and c = 62.3 A. The asymmetric unit contains one molecule with a solvent content of 52%. The crystals were stable in the X-ray beam and diffract beyond 3.2 A. The native data to 3.5 A have been collected and the structure determination is in progress.

Ascitic fluid cholesterol in malignant and tubercular ascites.

Cholesterol was estimated in ascitic fluid of 44 patients (29 malignant and 15 tubercular). Mean ascitic cholesterol level was significantly higher in malignant ascites (89.52 mg/dl) as compared to tubercular ascites (35.07 mg/dl). At a cut off value of 54.5 mg/dl (mean in tubercular ascites + 2SD), the sensitivity, specificity, positive and negative predictive value and overall diagnostic accuracy for differentiating malignant from tubercular ascites was found to be 89.65%, 100%, 100%, 83.33% and 93.18% respectively. Ascitic fluid cholesterol estimation is a reliable and simple test for differentiating malignant ascites from tubercular ascites.

Ascitic fluid cholesterol in differential diagnosis of ascites.

Cholesterol was estimated in ascitic fluid of 89 patients (29 malignant and 60 non-malignant ascites). Mean ascitic cholesterol level was significantly higher in malignant ascites (89.52 mg/dl) as compared to non-malignant ascites (29.93 mg/dl). At a cut off value of 48 mg/dl, the sensitivity, specificity, positive and negative predictive value and overall diagnostic accuracy for diagnosing malignant ascites is 96.5%, 96.6%, 93.3%, 98.3% and 96.6% respectively. Ascitic fluid cholesterol estimation is an easy and reliable test for differentiating malignant ascites from non-malignant ascites.

Purification, crystallization, and X-ray diffraction studies of lactotransferrin from buffalo colostrum.

Lactotransferrin is an iron-binding protein. It has been purified from buffalo colostrum. The purified lactotransferrin has been crystallized in 10% ethanol solution. The crystals are orthorhombic and the space group is P2(1)2(1)2(1) with unit cell dimensions a = 161.70 A, b = 155.75 A, c = 113.48 A. The asymmetric unit contains three molecules of the protein with a solvent content of about 59%. The crystals were stable in the X-ray beam and diffract beyond 3.5 A resolution. The native data have been collected and the structure determination is in progress.

Endoscopic and histopathological study of duodenitis.

Fifty patients who presented with symptoms suggestive of disease related to peptic acidity having endoscopic evidence of duodenitis were analysed. Endoscopic duodenal biopsy was done in all these patients. Histologically duodenitis was labelled if there was infiltration of epithelial layer. Male to female ratio was found to be 3:2. Duration of symptoms in the patients ranged from less than one month to more than 5 years. Possible aetiological factors like drugs, alcohol and smoking were established in 26 patients (52%), drugs being the commonest (26%). Stool examination showed cyst or ova of parasites in 8 patients (16%). Endoscopically multiple hyperaemic patches were seen in 15 (30%), erosions in 19 (38%), coarse mucosal folds in 5 (10%), nodules in 2 (4%) and multiple lesions in 9 (18%) patients. Histological and endoscopical correlationship was established in 40 (80%) cases.

Jaundice in Plasmodium falciparum.

Thirty-two patients of smear positive Plasmodium falciparum malaria having jaundice were analysed retrospectively. Majority of the cases were in the age group of 31-40 years. Serum bilirubin levels ranged from 2 mg to 40 mg%. Fourteen (42.6%) had serum bilirubin above 10 mg%. Conjugated bilirubinaemia was found in twenty one patients (65.5%), unconjugated in 4 (12.5%) while 7 patients (21.8%) had a mixed pattern. Serum transaminases were high in 21.8% patients. Twenty five patients (78%) had associated azotaemia, 11(34.3%) had intravascular haemolysis and 3(9.3%) had possible cerebral malaria. Hepatosplenomegaly was seen in all the 32 patients. Mortality was 21% but none died of hepatic encephalopathy. Histologically the most consistent finding in liver biopsies was reticulo-endothelial cell hyperplasia. Pigmentation in kupffer cells, fatty change, sinusoidal and portal infiltration and cholestasis were the other features seen.

Amine production by Streptococcus lactis under different growth conditions.

The highest amount of histamine, tyramine and tryptamine were produced by S. lactis at 30 degrees C in 24 h at pH = 5.0. Maximum amount of different amines was noted in a growth medium lacking NaCl. After addition of NaCl even at 0.5% concentration, slight inhibitory effect on the synthesis of these amines was obtained.

Dynamic orientation of spin I nuclei. II.

The Jeffries-Abragam effect in an electron-nuclear coupled spin system (S = (1/2), I = 1) is studied in detail. From a population-distribution analysis of the system, the nuclear orientation parameters are computed and their temperature dependence discussed. Conditions for obtaining stimulated emission are examined in detail. The results are compared with those of an earlier paper.