Influence of PGRs on carbohydrate content in Lipaphis erysimi (Kalt.)

Six compounds (IBA, chlorogenic acid, cytokinine, GA3, alar B-9 and maleic hydrazide) belonging to four different categories of plant growth hormones were used to study their effect on carbohydrate content in L. erysimi. The second instar nymphs (48 hr old) were given both dipping and leaf surface treatment with 1024 ppm concentration of compounds for two time intervals i.e. 48 and 96 hr. The carbohydrate content decreased after treatment with 4 of the plant growth regulators i.e. GA3, alar B-9, IBA and chlorogenic acid with maximum suppression in GA3 treatment. Cytokinine did not induce any derogatory influence on carbohydrate content. The treatment with maleic hydrazide, on the other hand enhanced the carbohydrate content. It could be concluded that the application of these PGRs affected the carbohydrate synthesis or metabolism.     

Imprint cytology in the diagnosis of Helicobacter pylori. Does imprinting damage the biopsy specimen?

OBJECTIVE: To investigate the efficacy of imprint cytology in the diagnosis of Helicobacter pylori infection and whether it damages the biopsy specimen for subsequent histologic examination. STUDY DESIGN: Two antral biopsies were taken from 76 patients with dyspeptic symptoms undergoing upper gastrointestinal endoscopy. Imprint cytology was made from the first specimen. This specimen was fixed in 10% formalin and sent for histopathologic examination. The second specimen was directly fixed in 10% formalin for routine histopathologic examination without being used for an imprint. The imprint smears were examined by cytopathologists. The biopsy specimens were examined by pathologists who did not know which specimens were used for the imprints. RESULTS: H pylori was seen in smears from 55 (72%) patients and in both biopsy specimens from the same patients. The pathologists could not recognize the biopsy specimens from which the imprints were made. Concordance between imprint cytology and histopathology was 100%. CONCLUSION: Imprint cytology is a suitable test for H pylori diagnosis, and imprints do not adversely affect the quality of the biopsy specimen.     

Gastropathy and defense mechanisms in common bile duct ligated portal hypertensive rats

Portal hypertensive gastropathy is associated with a broad spectrum of gastric mucosal damage inspite of decreased gastric acid secretion, suggestive of compromised endogenous protective mechanisms. To determine the mechanisms of damage in portal hypertensive gastropathy we measured lipid peroxidation, glutathione, antioxidant and lysosomal enzymes in gastric mucosal homogenates from male Wistar rats with elevated intrasplenic pulp pressure, eighteen days after common bile duct ligation. Thiobarbituric acid-reactive substances and lysosomal enzymes (-glucuronidase and acid phosphatase) were increased in the common bile duct ligated group as compared to the sham-operated group. The levels of antioxidant defense enzymes, superoxide dismutase, glutathione peroxidase, catalase and glutathione were decreased as compared to the sham-operated controls. Pre-operative vitamin E administration decreased mucosal lipid peroxidation increased the levels of antioxidant defense enzymes and lowered the lysosomal enzymes. The plasma vitamin E levels in this group were lower when compared to animals receiving it post-operatively. In conclusion, free radical and lysosomal enzyme mediated damage may play a role in portal hypertensive gastropathy.     

Functional characterization of cultured cells derived from an intraepidermal carcinoma of the skin (IEC-1)

We have successfully isolated a cell line (IEC-1) from an intraepidermal carcinoma of the skin of a patient and compared its behavior, in vitro, to normal human epidermal keratinocytes (HEK) and squamous cell carcinoma cell lines (SCCs). HEK differentiation comprises an initial growth arrest followed by an induction of squamous differentiation-specific genes such as transglutaminase type 1 (TG-1). Using thymidine uptake and TG-1 induction as markers of proliferation and differentiation, respectively, we were able to show that HEKs and the IEC-1 cells undergo growth arrest and induce TG-1 mRNA expression in response to various differentiation-inducing stimuli, while neoplastic SCC cell lines did not. However, differentiation in HEKs was an irreversible process whereas differentiation of the IEC-1 cells was reversible. Furthermore, growth of IEC-1 cells in organotypic raft cultures revealed differences in their ability to complete a squamous differentiation program compared with that of normal HEKs. The IEC-1 cells also exhibited a transitional phenotype with respect to replicative lifespan; HEKs had a lifespan of 4-6 passages, IEC-1 cells of 15-17 passages, and SCC cells were immortal. These alterations in IEC-1 cell behavior were not associated with functional inactivation or mutations of the p53 gene. These data indicate that the IEC-1 cells, derived from a preneoplastic skin tumor, exhibit differences in their ability to undergo terminal differentiation and have an extended replicative lifespan.     

Ontogenic changes in enzymes of carbon metabolism in relation to carbohydrate status in developing mungbean reproductive structures

The content of free sugars and the activities of enzymes involved in carbon metabolism-sucrose synthase, acid and alkaline invertase, phosphoenol pyruvate carboxylase, malic enzyme and isocitrate dehydrogenase were determined during seed development in mungbean pods. A decrease in carbohydrate content of pod wall from 10 to 25 days after flowering (DAF) and a concomitant increase in the seed till 20 DAF was observed. Sucrose remained the dominant soluble sugar in the pod wall and seed. In the branch of inflorescence and pod wall, the activities of sucrose metabolizing enzymes, viz. acid and alkaline invertase, sucrose synthase (synthesis and cleavage) and sucrose phosphate synthase were higher at 5-10 DAF, whereas in seed the maximum activities of these enzymes were observed at the time of maximum seed filling stage (10-20 DAF). High activities of sucrose synthase at the time of rapid seed filling can be correlated to its sink strength. Higher activities of phosphoenol pyruvate carboxylase in the branch of inflorescence and pod wall than in seed may indicate the involvement of the fruiting structure for recapturing respired CO2. High activities of isocitrate dehydrogenase and malic enzyme in the seed at the time of rapid seed filling could provide NADPH and carbon skeletons required for the synthesis of various seed reserves.     

Vaccine protection against simian immunodeficiency virus by recombinant strains of herpes simplex virus

An effective vaccine for AIDS may require development of novel vectors capable of eliciting long-lasting immune responses. Here we report the development and use of replication-competent and replication-defective strains of recombinant herpes simplex virus (HSV) that express envelope and Nef antigens of simian immunodeficiency virus (SIV). The HSV recombinants induced antienvelope antibody responses that persisted at relatively stable levels for months after the last administration. Two of seven rhesus monkeys vaccinated with recombinant HSV were solidly protected, and another showed a sustained reduction in viral load following rectal challenge with pathogenic SIVmac239 at 22 weeks following the last vaccine administration. HSV vectors thus show great promise for being able to elicit persistent immune responses and to provide durable protection against AIDS.     

The importance of homologous recombination in the generation of large deletions in hybrid plasmids in Amycolatopsis mediterranei

The whole nucleotide sequence of pT3.2I, the smallest plasmid of the acidophilic bacterium Thiobacillus T3.2, has been determined. pT3.2I is 15,390 bp long with a 53.7% GC content. Different regions can be defined in it: one 2569-bp putative insertion sequence similar to other insertion sequences of some Agrobacterium Ti plasmids; and a longer sequence, which occurs in two almost identical copies, differing only in a 1-bp deletion (6406 and 6405 bp). Several open reading frames and some smaller sequences were found in this duplicated region: ORFA and ORFG, encoding a putative polyol dehydrogenase and a putative RepA replication protein, respectively, an 83-bp sequence which could code for an antisense RNA, and a 36-bp region highly homologous to ori sequences of ColE2- and ColE3-related plasmids. Another putative gene, ORFH, is only present in the longer copy of this region (it is deleted in the short copy) and might encode a 90-amino-acid polypeptide which could act as a second replication protein, RepB. Based on sequence comparisons, pT3. 2I can be related to plasmids in the pColE2-CA42 incB incompatibility group.     

Clonal propagation of Acacia catechu Willd. by shoot tip culture

A method is described for in vitromicropropagation through shoot apices of Acaciacatechu Willd., a semi-arid tree valued for Katha (atanin-like substance obtained from red heart wood of10–20 year old trees) and timber. Explants wereexcised from 15-days-old in vitro grownseedlings raised from superior seed stocks. Shoot budinduction from shoot apex explants was observed onMurashige and Skoog's (MS) [12] medium containingvarious growth regulators. A maximum of 12 shoots wasobtained on MS medium supplemented with 1.5 mg/l 6-benzylaminopurine (BAP) and 1.5 mg/l kinetin.Well-developed shoots (3–4 cm long) were rooted on strength MS medium with 3.0 mg/l indole-3-acetic acid (IAA) and sucrose 1.5%. In vitro regenerated plantlets of A. catechu were transferred to field conditions.     

A critical evaluation of copper metabolism in indian wilson’s disease children with special reference to their phenotypes and relatives

Wilson’s disease is an autosomal recessive disorder of copper accumulation in various organs, with most common clinical manifestations such as hepatic, neurological, and renal dysfunctions. Serum copper and ceruloplasmin in Wilson’s disease were significantly lower as compared to normals, controls, and relatives of Wilson’s disease patients, whereas marked hypercupriuria (145 ± 7 μg/24 h) was observed in Wilson’s children only. A good correlation (r = 0.92) was found between non-ceruloplasmin-bound copper and 24-h urinary copper excretion in Wilson’s disease patients. Further, copper studies among the different phenotypes of Wilson’s disease revealed substantially low serum ceruloplasmin and a marked hypercupriuria in Wilson’s disease children associated with renal tubular acidosis as compared to the patients with either hepatological or neurological manifestations. Serum ceruloplasmin levels in 14 patients of Wilson’s disease were between 14 and 20 mg/dL. These patients of Wilson’s disease were confirmed by measuring liver biopsy copper, which was about nine times higher than normal hepatic copper content. During the family screening by copper studies, four asymptomatic siblings were diagnosed for Wilson’s disease. These subjects were then started on D-penicillamine therapy because presymptomatic treatment prevents progression of the disease complications.