Search

The recent emergence of dengue hemorrhagic fever/dengue shock syndrome (DHF/ DSS) in India has been a source of concern. In the present study a quantitative comparison of 406 nucleotide long sequence from the capsid-premembrane junction region (C-PrM) of 9 dengue virus type 2 (DEN-2) isolates from Delhi with 10 DEN-2 isolates from diverse geographic areas provided sufficient information for estimating genetic relationships. The data indicated that the 1996 epidemic of DHF in Delhi was caused by genotype IV strains of DEN-2. This genotype, perhaps, displaced genotype V strains of DEN-2, which was circulating genotype in 1967. The period during which this displacement had occurred is not clear from the present study. Nonetheless, similar experience in four countries in Latin America and in Sri Lanka suggest that the introduction of new genotypes of DEN-2 displacing the circulating genotype may be associated with the appearance of DHF/DSS. More work is required to elucidate this hypothesis. Transitions at nucleotide positions 406 and 431 resulted in amino acid substitutions near (aa position 104, methionine --valine) and at the hinge region (aa position 112, valine --alanine) of C-PrM, respectively in all/most genotypes of group III and IV DEN-2 viruses analysed. Most of these virus strains have been isolated from DHF/DSS outbreaks. Significance of this observation is discussed. The data presented in this study suggest the utility of C-PrM sequence analysis for molecular epidemiology of dengue viruses.

The structural changes in the granulosa lutein cells in the pregnant cows between 60 and 245 days, were observed. The polyhedral or plump cells had an acido-philic cytoplasm around the spherical nucleus. The glycogen granules increased in number up to 230 days of pregnancy. The lipid globules increased in size and amount during advanced pregnancy. The mitochondria showed a wide range of variations in shape and size. The matrix of many mitochondria contained dense inclusions which replaced the entire matrix in late pregnancy. The endoplasmic reticulum was chiefly of smooth type but a few stacks of the rough variety could be seen in the early days of pregnancy. Sometimes, whorls of smooth-surfaced endoplasmic reticulum enclosing mitochondria were seen. The Golgi complex was fully developed in the granulosa cells of all cases studied. The dense granules and lipid globules increased in size and number in the older corpora lutea. The cell surface showed numerous infoldings of the plasma membrane.

1. The production rates of bacteria in the rumen of buffalo (Bos bubalis) calves were estimated using an isotope-dilution technique. A series of fifteen experiments was done with animals given green maize and nine experiments with animals given cowpea (Vigna unguiculata).2. The turnover time ranged from 205 to 567 min in the group given green maize and from 330 to 648 min in animals offered cowpea. The production rates of bacteria were (mean±SE; g/d) 145.77±7.240 and 237.09±11.847 in animals given green maize and cowpea respectively.3. There was a significant correlation between bacterial production rates and dry matter intake, digestible organic matter and total volatile fatty acids formed in the rumen.4. Regression equations obtained for the two foodstuffs were different suggesting that the bacterial growth rate may vary depending upon the quantity and quality of foodstuff digested and possibly the ratio nitrogen: energy of the foodstuff.

The testicular seminal pathway in the camel is divided into two portions: an intratesticular and an extratesticular portion. The intratesticular seminal pathway consists of three portions: a 'tapering terminal segment' of the seminiferous tubules opening into the receptacle, the tubuli recti with three parts and the rete testis. The extratesticular portion consists of the rete testis, as an extension of the intratesticular portion and an elongated sac from which 6-7 ductuli efferentes originated. The tapering terminal segments are lined by modified Sertoli cells. Both, the tubuli recti and rete testis, are lined by simple cuboidal to columnar cells. The epithelium of the ductuli efferentes which, at its origin from the sac is simply cuboidal, gradually changes to an epithelium that consists of alternating groups of high-columnar ciliated and low-columnar non-ciliated cells. The strongly PAS-positive basement membrane of the ductuli efferentes is surrounded by a thin circular layer of smooth muscle fibres. The pseudo-stratified columnar epithelium of the epididymis is supported by an intensely PAS-reactive basement membrane. Morphological changes in the epithelium of the head and body regions of the epididymis due to seasonal variations are well marked in the camels of all age groups.

The bacteria production rates in the rumen have been estimated by injecting 14C- and 35S-labelled mixed rumen bacteria, either live or killed by treatment with formaldehyde, into the rumen and applying isotope dilution technique. The rate of bacteria production when estimated by using either live- or dead-(protected-)labelled bacterial cells were comparable.

Total microbial protein synthesis rates in the rumen of buffaloes were estimated by isotope dilution technique, using 131I-albumin treated with tannic acid as a marker. The animals were fed groundnut cake treated with formaldehyde to meet 50% of their digestible crude protein (DCP) requirement and 2.5% urea molasses mixture was given to meet the remaining requirement of DCP. Wheat straw was fed as the basal roughage. The total average microbial protein synthesis was 58.14 g/day.

Histological and a few histochemical studies were done on the testes of 34 camels between 4 and 20 years of age, during three seasons: the tunica albuginea of the testes was composed of collagenous and a few elastic fibers. Isolated bundles of the smooth muscle fibers were observed in the capsule. The mediastinum testis and its radiating septula into the parenchyma also consisted of mainly collagenous and a few elastic fibers. The interstitial tissue was composed of Leydig cells and a network of reticular fibers. These cells increased in volume in the rutting period from December to March, and were distorted and reduced in volume in the nonrutting period from April to November. The seminiferous tubules were 113--250 micrometer in diameter, and were lined by many layers of spermatogenic cells and a single layer of Sertoli cells. The spermatogenesis was observed as a continuous process throughout the year, particularly in the camels between 4 and 15 years of age. Almost in all the testes studied, three types of spermatogonia, two to three layers of primary spermatocytes, rarely secondary spermatocytes and spermatids in two stages were observed. The spermatozoa were present attached to the Sertoli cells as well as free in the lumen of the tubules. The oval head of the spermatozoa was characterized by the presence of an elongated pointed, strongly PAS-positive acrosome.

SummaryThe rates of production of protozoa in the rumen of buffalo calves have been estimated using a single-injection isotope dilution technique. The calves were fed at 2 levels of crude protein, namely, 13% lower and 19% higher than that recommended by the National Research Council. The animals were given their rations at 2-h intervals for 3 weeks. Thereafter 14C-labelled rumen protozoa were injected into the rumen of each calf in a single injection. Samples of the rumen liquor were drawn at various time-intervals for 10 h and were analysed for the concentration of protozoa and radioactivity. The decline in the specific radioactivity of protozoa cells in the rumen as a function of time was used for calculating half life (t½). A mathematical equation was used to calculate the rate of production of protozoa. The average t½ was 1077 min for both groups and the rates of production of protozoa were 73·9 and 92·1mg/min in groups fed on low and high planes of crude protein respectively, showing that the production of protozoa is significantly (P < 0·01) higher in animals consuming a ration high in crude protein.

Im Gelbkorper von Kuhen wurden wahrend der Periode von 80–240 Trachtigkeitstagen in den Granulosaluteinzellen Einschlusse gefunden, die beinahe ganze Mitochondrien ausfullten. Die Elektronendichte war der von Fett-Tropfchen ahnlich. Die Einschlusse konnten morphologisch dahin deuten, dass die Mitochondrien zur Steroidsynthese der Granulosazellen enge Beziehungen haben.

— Monkeys exposed to a rhythmically flickering light (flicker frequency 7/sec, intensity 1614 lumens/m2) show a higher incorporation of intracisternally administered l-(U-3H)-lysine into proteins of the visual cortex as compared to monkeys kept in darkness. An increase in specific radioactivity is noticed in both the soluble and particulate (including membrane linked) proteins. The 105,000 g supernatant proteins from the visual cortex have been fractionated on DEAE-cellulose columns followed by resolution of each fraction on polyacrylamide gels. The results suggest that there is a group of acidic low molecular weight proteins whose synthesis is significantly stimulated during the exposure of the animal to flickering light. The fractions give immunological cross-reaction with anti S-100 Serum.