Purification, Characterization, and Antifungal Activity of Chitinase from Streptomyces venezuelae P10

Streptomyces venezuelae P(10) could produce extracellular chitinase in a medium containing 0.6% colloidal chitin that was fermented for 96 hours at 30 degrees C. The enzyme was purified to apparent homogeneity with 80% saturation of ammonium sulfate as shown by chitin affinity chromatography and DEAE-cellulose anion-exchange chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the enzyme showed a molecular weight of 66 kDa. The chitinase was characterized, and antifungal activity was observed against phytopathogens. Also, the first 15 N-terminal amino-acid residues of the chitinase were determined. The chitin hydrolysed products were N-acetylglucosamine and N, N'-diacetylchitobiose.

Hyperinsulinemia and dyslipidemia in non-diabetic benign prostatic hyperplasia

BACKGROUND

BPH is a multifactorial disease. Several studies have elucidated the role of hormones and growth factors in its etiology. Insulin is a growth-stimulating hormone. Previous studies have reported the association between hyperinsulinemia, dyslipidemia and BPH in patients with metabolic disorders like diabetes. We evaluated insulin and lipid profile parameters in non-diabetic BPH cases and correlated it with prostate size.

METHODS

50 symptomatic BPH cases and 38 controls were included in this study. Fasting serum insulin concentrations were measured by radioimmunoassay. Insulin resistance was assessed by HOMA. Fasting glucose, total cholesterol and triglycerides were quantified by enzymatic methods. HDL-cholesterol was quantified by phosphotungstate magnesium chloride method. LDL-cholesterol was calculated by Friedwald's formula.

RESULTS

Fasting serum insulin, HOMA, total cholesterol, and LDL-cholesterol were significantly higher and HDL-cholesterol was significantly lower in cases as compared to controls. Insulin was significantly associated with prostate size, cholesterol, triglycerides, VLDL-cholesterol and LDL-cholesterol in BPH cases. Stepwise regression analysis showed insulin as an independent risk factor in the development of BPH.

CONCLUSIONS

Hyperinsulinemia associated with insulin resistance is an independent risk factor in the development of BPH.

Dibutyl phthalate, the bioactive compound produced by Streptomyces albidoflavus 321.2

It was found that the bioactive compound, dibutyl phthalate, was produced by a new soil isolate Streptomyces albidoflavus 321.2. Once this active compound was recovered by ethyl acetate from the fermented broth, being possible to isolate 13.4 mg/l, it was purified by paper, silica gel column, thin layer and gas chromatography. Structure was determined by analysing UV, IR and GC-MS spectra. During analysis, such active compound showed strong activity against gram-positive and gram-negative bacteria, as well as unicellular and filamentous fungi. The antimicrobial activity of the compound was reversed by the amino acid proline. No acute toxicity was observed.

Possible link between glycated hemoglobin and lipid peroxidation in hyperthyroidism

BACKGROUND

Glycated hemoglobin (HbA1C) levels are enhanced by elevated glucose concentrations. Glycation of hemoglobin is also modulated by lipid peroxides, ascorbic acid and reduced glutathione (GSH). We determined the strength of the relationships among these variables in a group of hyperthyroid patients.

METHODS

Twenty-two untreated hyperthyroid patients and 17 healthy controls were recruited for the study. Whole blood GSH, HbA1C, plasma lipid peroxides, ascorbic acid and fasting glucose were analyzed in both the groups. Direct and partial correlation analysis was performed to explore the possible relationships between these variables.

RESULTS

In hyperthyroid patients, HbA1C and lipid peroxides levels were found to be significantly increased than the controls. Ascorbic acid and GSH were decreased significantly in the test group when compared with the healthy control group. With partial correlation analysis, fasting glucose and lipid peroxides were found to have a significant positive correlation with HbA1C. Ascorbic acid and GSH showed no significant association with HbA1C levels.

CONCLUSION

These data suggest that HbA1C levels are closely associated with fasting glucose and lipid peroxides in hyperthyroid patients. Therefore, serum lipid peroxides level should be kept in mind while interpreting HbA1C as a long-term glycemic index in hyperthyroid cases.

Increased protein glycation in non-diabetic pediatric nephrotic syndrome: possible role of lipid peroxidation

BACKGROUND

Malondialdehyde (MDA), ascorbic acid and reduced glutathione (GSH) have been reported to play a possible role in glycation of proteins. This study was performed to evaluate this correlation in nephrotic syndrome patients by comparing the levels of fructosamine with MDA, ascorbic acid and GSH.

METHODS

Fifteen children with nephrotic syndrome during relapse and 10 age- and sex-matched healthy controls were enrolled for this study. Whole blood GSH, plasma MDA, total ascorbic acid and fasting glucose were analyzed in both the groups. Partial correlation analysis was performed to predict the independent association of MDA, ascorbic acid and GSH on fructosamine.

RESULTS

Plasma MDA and fructosamine levels were found to be increased in nephrotic syndrome patients when compared with controls. Plasma ascorbic acid and whole blood GSH were decreased in nephrotic group vs. healthy controls. Partial correlation analysis showed a significant positive correlation between fructosamine and MDA.

CONCLUSIONS

Present data point to a possible involvement of MDA in the glycation of protein in non-diabetic nephrotic syndrome patients, and provide support for the potential use of an antioxidant therapy in these patients.

Characterization and identification of chitinase producing Streptomyces venezuelae P10

In an attempt to isolate chitinase producers from soil, a streptomycete strain was found potent using natural chitin as the substrate. Chitinolytic activity was tested directly on agar plates, also with crude enzyme. Chitinase assay showed that the isolate could produce 0.8 U/ml of the enzyme. The morphological, cultural, physiological and biochemical characters of the isolate P10 were studied, and identified as Streptomyces venezuelae P10.

Small group discussion followed by presentation as a revision exercise at the end of a teaching module in biochemistry

BACKGROUND

We evaluated the effect of student-dominated small group discussion followed by faculty-moderated presentation as a revision exercise after completion of a teaching module in biochemistry. We assessed the understanding of graduate medical students on the topic and the gain in retention of information, if any, after 15 days.

METHODS

Small group discussions involving 11-12 students in each group were conducted on 12 application-oriented problems in 'amino acid metabolism'. A group leader among the students helped to conduct the discussions. While two-thirds of the problems were taken up after the discussion during faculty- or student-moderated interactive presentations, the remaining were not. The effects on low-, medium- and high achievers were evaluated by a pre-test and post-test with multiple choice questions immediately after the session. A subjective feedback was also obtained. To test short-term memory, a post-test with the same multiple choice questions was conducted after 15 days.

RESULTS

The exercise was effective and equally beneficial for low-, medium- and high achievers. The gain was maximum when faculty moderated the presentation session. The students' retention of their gain after 15 days was complete. All the students wanted more such sessions in future.

CONCLUSION

Student-dominated small group discussion followed by a faculty-moderated presentation is an effective, revision exercise for undergraduate medical students.

TRACE METALS IN CANCER PATIENTS AND THEIR CORRELATION WITH RENAL FUNCTION

ABSTRACTTwo trace elements, copper (Cu) and zinc (Zn) in serum are elevated in cancer patients since both areconstituents of super oxide dismutase (SOD) as metalloenzyme, the enzyme that scavenge free radicals andactivated oxygen species in the body. The study of 52 cancer patients comprising of 31 carcinoma stomachand 21 breast cancer showed the elevation of both of these trace elements in serum when compared to 32healthy controls and effected the kidney functions as a consequences. Serum Cu and Zn were estimated byAtomic Absorption Spectrometer (AAS), analyzed statistically by student "t" test and marked elevationwas observed in cancer patient compared to healthy controls. Serum Cu and Zn values were 98.13 ± 17.49μg/dl 99..57 ± 13.91 μg /dl respectively in 38 healthy subjects and these trace metals were 156.23 ± 31.02 μg/dl and 171.86 ± 35.15 μg/dl in 52 cancer patients showing significant elevation (P <0.001). These elevatedelements were routed through kidneys and damaged nephrons since both of them are cationic heavy metals.Nephrotoxicity of these trace metals was reflected as elevated level of blood urea and creatinine and werefound to be 27.44 ± 7.72 mg /dl and 0.83 ± 0.30 mg/dl in control groups and 64.49 ± 49 mg /dl and 1.60 ± 0.72mg/dl in cancer patients respectively, a significant elevation (P<0.001) in study group. The elevation ofthese parameters may indicate renal origin.Key Words: Serum copper, serum zinc, super oxide dismutase, carcinoma stomach, carcinoma breastand nephrotoxicity.

Ester antibiotic accumulation by Streptomyces hygroscopicus

In an attempt to maximize the ester antibiotic production by Streptomyces hygroscopicus D1.5, its efficacy was found to be enhanced by manipulation of the nutrient and physical environment. The two stage fermentation using seed inoculum (10% v/v) resulted in better production while fermentation continued for 5 days in pH 7.0 at 30 degrees C. Enhanced yield was also observed in whole cell immobilization. Under entrapment, maximum yield was achieved at 7th and 9th day of fermentation for mycelia and spore. In addition, the beads could be reused up to the 3rd cycle.

Duckweed (Lemna polyrhiza) leaf meal as a source of feedstuff in formulated diets for rohu (Labeo rohita Ham.) fingerlings after fermentation with a fish intestinal bacterium

Eight isonitrogenous (35% crude protein approximately) and isocaloric (4.2 kcal g(-1) approximately) diets were formulated including raw and fermented duckweed (Lemna polyrhiza) leaf meal at 10%, 20%, 30% and 40% levels. A particular bacterial strain (Bacillus sp.) isolated from carp (Cyprinus carpio) intestine and having extracellular amylolytic, cellulolytic, proteolytic and lipolytic activities was used for leaf meal fermentation for 15 days at 37 degrees C. The fibre content of leaf meal reduced from 11.0% to 7.5% and the antinutritional factors, tannin and phytic acid, were reduced from 1.0% to 0.02% and 1.23% to 0.09%, respectively after fermentation. However, the available reducing sugars, free amino acids and fatty acids increased in the fermented leaf meal. The response of rohu, Labeo rohita, fingerlings fed the experimental diets for 80 days was compared with fish fed a fish meal based reference diet. On the basis of growth response, food conversion ratio and protein efficiency ratio, 30% fermented Lemna leaf meal incorporated in the diet resulted in the best performance of rohu fingerlings. In general, growth and feed utilization efficiencies of fish fed fermented leaf meal containing diets were superior to those fed diets containing raw leaf meal. The apparent protein digestibility (APD) decreased with increasing levels of leaf meal irrespective of treatment. The APD for raw leaf meal was lower at all levels of inclusion in comparison to those for the fermented meals. The highest carcass protein and lipid deposition was recorded in fish fed the diet containing 30% fermented leaf meal. The results showed that fermented Lemna leaf meal can be incorporated into carp diets up to 30% level compared to 10% level of raw meal.

Survey of antimicrobial streptomycetes from soils of West Bengal: characterization and identification of potent broad spectrum antibiotic producing Streptomyces albidoflavus 321.2

Survey of 611 streptomycetes isolates from 330 soil samples from various parts of West Bengal were done for their antimicrobial activity against Gram positive, Gram negative bacteria, unicellular and filamentous fungi. The strain 321.2 showed inhibition against all the test organisms used and found as potent. The morphological, cultural, physiological and biochemical characters were studied, compared with known species and identified as Streptomyces albidoflavus. This strain produces an antibiotic.

Esterase isozyme polymorphism, specific and nonspecific esterase, syngenic lines development and natural occurrence of a thermostable esterase in the tropical silkworm Bombyx mori L

Esterase isozyme polymorphism was documented for digestive juice and haemolymph of the tropical multivoltine silkworm, Bombyx mori L., breed CB5 (GP) and its syngenic lines (CB5Lm(e)-1, CB5Lm-2 and CB5Lm-5) using alpha- and beta-naphthylacetate separately as nonspecific substrates (Ogita, Z., Kasai, T., 1965. Genetico-biochemical analysis of specific esterases in Musca domestica. Jpn. J. Genet. 40, 173-184). Polymorphism existed in the isozyme pattern of alpha-esterase with two or three bands in digestive juice and three to five bands in haemolymph. No polymorphism was observed in beta-esterase isozyme pattern having four bands in digestive juice and two bands in haemolymph. During the course of esterase isozyme studies, the presence of some specific alpha-esterase bands (Est-1, 4 and 5) in haemolymph and beta-esterase bands (Est-1, 2 and 3) in digestive juice were observed. But both alpha- and beta-esterase bands Est-3 and 4 in digestive juice and Est-2 and 3 in haemolymph were found to be nonspecific. Nonspecific beta-esterase band (Est-3) in haemolymph of CB5 (GP) and its syngenic lines withstood a temperature up to 80+/-1 degrees C for 10 min. No thermostable band was observed in the isozyme zymogram of alpha-esterase in digestive juice and haemolymph or beta-esterase in digestive juice. Overall, this study discusses the presence of esterase heterogeneity in the CB5 (GP) genepool, syngenic lines development, occurrence of specific alpha- and beta-esterase bands in digestive juice and haemolymph and thermostable beta-esterase band Est-3 in haemolymph in tropical silkworm Bombyx mori L.

Purification and characterization of a thermostable alpha-amylase from Bacillus stearothermophilus

A soil isolate of Bacillus stearothermophilus was found to synthesize thermostable alpha-amylase. The enzyme was purified to homogeneity by ammonium sulfate fractionation and IECC on DEAE-cellulose column. The purified enzyme was considered to be a monomeric protein with a molar mass of 64 kDa, as determined by SDS-PAGE. The enzyme showed a wide range of pH tolerance and maximum activity at pH 7.0. The temperature tolerance was up to 100 degrees C with more than 90% catalytic activity; the maximum activity was observed at 50 degrees C. Divalent metal ions exhibited inhibitory effect on the enzyme activity. However, proteinase inhibitor did not react positively.

Two naturally occurring insulin receptor tyrosine kinase domain mutants provide evidence that phosphoinositide 3-kinase activation alone is not sufficient for the mediation of insulin's metabolic and mitogenic effects

We have recently reported (1) that two naturally occurring mutants of the insulin receptor tyrosine kinase domain, Arg-1174 --> Gln and Pro-1178 --> Leu (Gln-1174 and Leu1178, respectively), both found in patients with inherited severe insulin resistance, markedly impaired receptor tyrosine autophosphorylation, with both mutant receptors being unable to mediate the stimulation of glycogen synthesis or mitogenesis by insulin when expressed in Chinese hamster ovary cells. However, these mutations did not fully prevent IRS-1 phosphorylation in response to insulin in these cells, suggesting that IRS-1 alone may not be sufficient to mediate insulin's metabolic and mitogenic effects. In the present study, we have demonstrated that these mutations also impair the ability of the insulin receptor to activate the transcription factor Elk-1 and promote GLUT4 translocation to the plasma membrane. Although at low concentrations of insulin, the mutant receptors were impaired in their ability to stimulate the tyrosine phosphorylation of IRS-1, at higher insulin concentrations we confirmed that the cells expressing the mutant receptors showed significantly increased tyrosine phosphorylation of IRS-1 compared with parental nontransfected cells. In addition, at comparable insulin concentrations, the association of the p85alpha subunit of phosphoinositide 3-kinase (PI3-kinase) with IRS-1 and the enzymatic activity of IRS-1-associated PI3-kinase were significantly enhanced in cells expressing the mutant receptors. In contrast, no significant stimulation of the tyrosine phosphorylation of Shc, GTP loading of Ras, or mitogen-activated protein kinase phosphorylation was seen in cell lines expressing these mutant receptors. Thus, no activation of any measurable mitogenic or metabolic response was detectable, despite significant insulin-induced phosphorylation of IRS-1 and its association with PI3-kinase in cells stably expressing the mutant insulin receptors. These findings suggest that PI3-kinase activation alone may be insufficient to mediate a wide range of the metabolic and mitogenic effects of insulin. Additionally, the data provide support for the notion that insulin activation of Ras is more closely linked with Shc, and not IRS-1, phosphorylation.

Blastomycosis. Report of a case with noninvasive, rapid diagnosis of dermal lesions by the Papanicolaou technique

BACKGROUND

Blastomycosis is a rare fungal infection that occurs most often in young to middle-aged men. A common route of infection is through continued contact with soil, occurring in such occupations as gardening and construction work. The skin and lungs are primarily affected. When the respiratory system is involved, blastomycosis may be misdiagnosed as pulmonary miliary tuberculosis.

CASE

A 54-year-old, African American male presented with dry cough and multiple verrucous skin lesions affecting the face, shoulder and legs. Chest roentgenography indicated bilateral lung involvement. The patient died following a short, difficult hospital course. Autopsy revealed verrucous skin lesions with dry, thick, raised margins and central necrosis and umbilication, and severe, diffuse pulmonary involvement clinically and radiologically, resembling miliary tuberculosis. A smear from a leg ulcer stained by the Papanicolaou technique revealed fungi within the giant cells.

CONCLUSION

Clinical and radiologic findings alone do not establish the diagnosis of blastomycosis. Respiratory involvement may lead to a misdiagnosis of pulmonary miliary tuberculosis. Sputum and bronchial washing examinations by a laboratory technique are in order. This case indicates that cytologic examination of the exudate from an ulcer may result in a strongly suggestive diagnosis.

Transgenic elite indica rice plants expressing CryIAc delta-endotoxin of Bacillus thuringiensis are resistant against yellow stem borer (Scirpophaga incertulas)

Generation of insect-resistant, transgenic crop plants by expression of the insecticidal crystal protein (ICP) gene of Bacillus thuringiensis (Bt) is a standard crop improvement approach. In such cases, adequate expression of the most appropriate ICP against the target insect pest of the crop species is desirable. It is also considered advantageous to generate Bt-transgenics with multiple toxin systems to control rapid development of pest resistance to the ICP. Larvae of yellow stem borer (YSB), Scirpophaga incertulas, a major lepidopteran insect pest of rice, cause massive losses of rice yield. Studies on insect feeding and on the binding properties of ICP to brush border membrane receptors in the midgut of YSB larvae revealed that cryIAb and cryIAc are two individually suitable candidate genes for developing YSB-resistant rice. Programs were undertaken to develop Bt-transgenic rice with these ICP genes independently in a single cultivar. A cryIAc gene was reconstructed and placed under control of the maize ubiquitin 1 promoter, along with the first intron of the maize ubiquitin 1 gene, and the nos terminator. The gene construct was delivered to embryogenic calli of IR64, an elite indica rice cultivar, using the particle bombardment method. Six highly expressive independent transgenic ICP lines were identified. Molecular analyses and insect-feeding assays of two such lines revealed that the transferred synthetic cryIAc gene was expressed stably in the T2 generation of these lines and that the transgenic rice plants were highly toxic to YSB larvae and lessened the damage caused by their feeding.

Optimisation of cultural conditions for antifungal antibiotic accumulation by Streptomyces rochei G164

To induce higher amount of antifungal antibiotic production by variation of cultural parameters has been studied. The maximum effectivity was found in sucrose as carbon source, peptone as nitrogen source and at pH 7.0. The effect of other selected factors were also evaluated in order to judge the variables that influenced antibiotic production.

Efficient transgenic plant regeneration throughAgrobacterium-mediated transformation of Chickpea (Cicer arietinum L.)

Three genotypes of chickpea ICCV-1, ICCV-6 and a Desi (local) variety were tested for plant regeneration through multiple shoot production. The embryo axis was removed from mature seeds, the root meristem and the shoot apex were discarded. These explants were cultured on medium containing MS macro salts, 4X MS micro salts, I35 vitamins, 3.0 mg/1 BAP, 0.004 mg/1 NAA, 3% (w/v) sucrose and incubated at 26(0)C. The explants were transformed withAgrobacterium tumefaciens strain LBA4404 with binary vector pBI121 containing theuidA andnptIl genes. Multiple shoots were repeatedly selected with kanamycin. The selected kanamycin resistant shoots were rooted on MS medium supplemented with 0.05 mg/1 113A. The presumptive transformants histochemically stained positive for GUS. Additionally, nptll assay confirmed the expression ofnptII in kanamycin resistant plants. Transgenic plants were transferred to soil and grown in the green house.