Localization of hup determinants in Rhizobium sp. sesbania.

Rhizobium sp. sesbania strain SRS 78, a Hup wild type carrying three plasmids was mutagenised using Tn5-sac BR cassette and clones carrying Tn5 insertion in plasmids were identified on the basis of transfer frequency of Tn5-sac BR labelled plasmids from Rhizobium to A. tumefaciens. Neomycin sensitive (Nms) clones were isolated from clones containing Tn5 labelled plasmids by plating on sucrose (5%). Nms clones did not show loss of hup activity. Preliminary results on curing studies indicated that hup genes are located on chromosome. These results were later confirmed by southern hybridization using plasmid pKHT30 containing hup genes of Azotobacter chroococcum. None of the three plasmids showed hybridization with hup gene probe while chromosomal DNA left in the wells showed positive signal.

"Orthoryhthmia" or postural cardiac dysrhythmia: clinical significance.

The objective of present paper is to present results of preliminary observations and studies carried out in fifty individuals developing cardiac dysrhythmia on assuming a supine posture. Detailed history taking, clinical examination, and study of metabolic parameters were carried out. Blood pressure, ECGs and rhythm strips were recorded in supine and upright postures, after exercise and DMT, after i.v. injection of atropine and after oral administration of probanthine. Majority of the individuals studied were asymptomatic. Palpitation was the commonest symptom. Bradycardia was observed in all as well as a low blood pressure. Supraventricular ectopic rhythm was the commonest dysrhythmia observed. Arythmia appeared on assuming a supine posture and tended to disappear in upright position and after exercise. I.v. atropine had a similar effect in a majority of cases, oral probanthine was not very effective. These observations highlight the existence of a hitherto unreported effect of posture on cardiac rhythm. This phenomenon appears to be a benign condition and can be termed as "orthorhythmia".

Styrene induced pancreatic changes in rodents.

Subchronic oral exposure to styrene in rodents (25 or 50 mg/kg/day in mice; 160 or 320 mg/kg/day in rats and guinea pigs, 5 days/week) for 4 weeks resulted in moderate congestion of pancreatic lobules, focal inflammatory reactions around islets (in mice) and altered serum insulin level while blood glucose levels remained unaffected. Increased beta cell degranulation together with characteristic neoformation of islets were predominantly seen in pancreas of guinea pigs.

Modulatory effects of metanil yellow on immunity in rodents.

Pathomorphological and immunological studies were carried out on rodents following oral administration of 0, 0.1, 0.25 and 0.5% (w/w) metanil yellow, mixed in diet, for 30 days. No significant change in hematologic parameters and histologic architecture of liver, kidney, mesenteric lymph node, thymus and urinary bladder was observed except for mild desquamation of intestinal villi and moderate changes in Peyer's patches of small intestine with higher doses. Among immunological parameters, significant enhancement in the primary humoral immune response (anti-SRBC IgM plaque forming cells of spleen) was observed with the lowest dose of metanil yellow while higher doses produced opposing effects. An elevated cutaneous delayed type hypersensitivity (DTH) reaction to SRBC was seen in 0.1% metanil yellow treated animals but higher doses did not influence the reaction. The treatment also caused changes in functional capabilities of macrophages. Although these immune alterations could hardly influence the local immunity of gut, as measured by the capacity of animals to cause rejection of Nippostrongylus brasiliensis parasite, the potential to modulate the immunity in general by metanil yellow however assumes considerable biological significance.