A comparison of genomes of sheep pox virus isolates.

Sheep pox virus DNAs from field isolates and vaccine strains were analysed by digestion with the restriction enzymes PstI and Bam HI. The restriction profiles generated by these enzymes show very close relationship between isolates from different geographical regions. The patterns of isolates can be grouped by the animal of origin (e.g. a cattle pox isolate can be differentiated from sheep pox isolate). The molecular weights of the genomes of different isolates varied from 91 to 94 MDa. The restriction enzyme patterns can be used as a molecular epidemiological tool for differentiating field and vaccine isolates.

Identification and size variation of terminal fragments of sheep pox virus genome.

Terminal fragments of sheep pox virus DNA identified by snap-back analysis showed terminal covalent cross-links. Southern blot hybridization using a terminal fragment probe confirmed the termini and terminal repeats (common sequences) of the sheep pox virus genome. Terminal fragment length variability was observed between virus isolates.

Unusual features of Helicobacter (Campylobacter) pylori--associated gastritis in India. A study of 200 cases.

Helicobacter (Campylobacter) pylori has been cultured from the antral biopsies of 85-90% of patients of gastritis, gastric ulcer and duodenal ulcer at different centres. Studies conducted all over the world have firmly implicated this organism in the aetiology of active superficial gastritis and recurrences of duodenal ulcer. Two hundred patients with upper abdominal pain, distension, vomiting and/or haemetemesis were subjected to OGD scopy. In 163 of these patients there was endoscopic evidence of gastritis; in 24 there was DU; in 3, GU and in 10 it was normal. Diagnosis of H pylori infection was made by the rapid biopsy urease test which is nearly 100% specific and 98% sensitive. 170 out of 200 patients were positive for H pylori. Among these were 138 patients of gastritis (84.6%); 22 cases of DU (91.6%); 2 cases of GU (66.6%) and 8 in whom endoscopy was normal. Histological examination of the antral biopsy specimens showed mild to severe infiltration of mucosa with lymphocytes and plasma cells. None of the 170 H pylori positive cases showed polymorphonuclear infiltration which has been stressed repeatedly by most Western authors to be characteristic of "active" superficial gastritis associated with H pylori infection. Even in those with a history of dyspepsia of barely 4 weeks duration or less there was no PMN infiltration in the mucosa. Thus the local response to infection by H pylori of the gastric mucosa is different in Indian patients.

Rapid diagnostic test of Campylobacter pylori infection in patients of gastritis, duodenal ulcer and gastric ulcer. A study of 100 cases.

Campylobacter pylori has been cultured from 85-90% of antral biopsies of patients of gastritis, duodenal ulcer and gastric ulcer at different centres in the world. It has been now firmly implicated in the aetiology of active gastritis as well as suspected to cause repeated recurrences of peptic ulcers. However, the organism is very fastidious and is difficult to grow by standard culture methods as a result of which low positivity is often obtained even in well equipped centres. The rapid biopsy urease test for the diagnosis of C pylori infection, in which the biopsy is directly cultured in a solid medium containing urea, is a very simple test. A change in colour indicates the growth of the organism. This test is 100% specific and 98% sensitive. We performed this test in 100 patients; 93 of gastritis, 6 of DU and 1 of GU during a three month period. 87 of 93 cases of gastritis (90%) and all 6 cases of DU (100%) were positive. The single case of gastric ulcer was negative. Treatment of C pylori positive cases showed that they responded poorly to 4 weeks therapy with tinidazole; 33% were cured after 2 weeks of 1.5 g amoxycillin daily, but all responded when the therapy was continued for 4 weeks.

The characterization of African strains of capripoxvirus.

Isolates of capripoxvirus collected from sub-Saharan Africa were compared in sheep, goats and cattle and by restriction endonuclease digestion of their purified DNA. Biochemical techniques were used to precisely identify strains of capripoxvirus for epidemiological investigations. Strains of capripoxvirus infecting cattle have remained very stable over a 30-year period and are closely related to strains recovered from sheep in Africa.

Polymorphism of mitochondrial DNA (mtDNA) in cattle and buffaloes.

Mitochondrial DNA (mtDNA) from two breeds of cattle, viz., [Hariana (Bos indicus), Holstein (Bos taurus)] and Indian water buffalo (Bubalis bubalus), was analyzed using 13 restriction endonucleases which recognized an average of about 40 six-base sites. Polymorphism among cattle was detected with six of these enzymes. The two Holstein differed at six sites, whereas the Hariana breed (Bos indicus) did not show any site polymorphism. Surprisingly, the Hariana type differed by only one site from one of the Holstein types. The total size of buffalo mtDNA was estimated to be 16.4 kb. Polymorphism within the Murrah buffalo breed was observed with respect to a Bg/I site. Scarcely any of the restriction fragments of buffalo mtDNA matched those of cattle mtDNA.

Haemaglobin and transferrin polymorphism in the Muzaffarnagri breed of sheep and its crosses with Corriedale.

Allelic frequencies for haemoglobins and transferrins in the Muzaffarnagri breed of sheep have been reported. All the three haemoglobin types were recorded. Seven transferrin phenotypes, TfAB, TfAD, TfBB, TfBC, TfBD, TfBE and TfDD, were observed. The gene frequencies for TfA, TfB, TfC, TfD and TfE were 0.032, 0.330, 0.001, 0.620 and 0.010, respectively.