Spirulina platensis prevents high glucose-induced oxidative stress mitochondrial damage mediated apoptosis in cardiomyoblasts

The current study was undertaken to study the effect of Spirulina platensis (Spirulina) extract on enhanced oxidative stress during high glucose induced cell death in H9c2 cells. H9c2 cultured under high glucose (33 mM) conditions resulted in a noteworthy increase in oxidative stress (free radical species) accompanied by loss of mitochondrial membrane potential, release of cytochrome c, increase in caspase activity and pro-apoptotic protein (Bax). Spirulina extract (1 μg/mL), considerably inhibited increased ROS and RNS levels, reduction in cytochrome c release, raise in mitochondrial membrane potential, decreased the over expression of proapoptotic protein Bax and suppressed the Bax/Bcl2 ratio with induced apoptosis without affecting cell viability. Overall results suggest that Spirulina extract plays preventing role against enhanced oxidative stress during high glucose induced apoptosis in cardiomyoblasts as well as related dysfunction in H9c2 cells.

Survivin, a molecular target for therapeutic interventions in squamous cell carcinoma

Squamous cell carcinoma (SCC) is the most common cancer worldwide. The treatment of locally advanced disease generally requires various combinations of radiotherapy, surgery, and systemic therapy. Despite aggressive multimodal treatment, most of the patients relapse. Identification of molecules that sustain cancer cell growth and survival has made molecular targeting a feasible therapeutic strategy. Survivin is a member of the Inhibitor of Apoptosis Protein (IAP) family, which is overexpressed in most of the malignancies including SCC and totally absent in most of the normal tissues. This feature makes survivin an ideal target for cancer therapy. It orchestrates several important mechanisms to support cancer cell survival including inhibition of apoptosis and regulation of cell division. Overexpression of survivin in tumors is also associated with poor prognosis, aggressive tumor behavior, resistance to therapy, and high tumor recurrence. Various strategies have been developed to target survivin expression in cancer cells, and their effects on apoptosis induction and tumor growth attenuation have been demonstrated. In this review, we discuss recent advances in therapeutic potential of survivin in cancer treatment.

Microbiome diversity in the sputum of patients with pulmonary tuberculosis

TB is a worldwide pandemic. India has the highest burden of TB, with WHO statistics for 2013 giving an estimated incidence figure of 2.1 million cases for India out of a global incidence of 9 million. Microbiota have been shown to be associated with many disease conditions; however, only few studies have been reported for microbiota associated with TB infection. For the first time, we characterized the composition of microbiota of TB patients of India, using high-throughput 16S rRNA gene sequencing and compared it with healthy controls. Phylum-level analysis showed that the relative abundance of Firmicutes and Actinobacteria was significantly higher in TB samples and Neisseria and Veillonella were two dominant genera after Streptococcus. In our study, significantly different core genera in TB and normal population were found as compared with the reported studies. Also, the presence of diverse opportunistic pathogenic microbiota in TB patients increases the complexity and diversity of sputum microbiota. Characterization of the sputum microbiome is likely to provide important pathogenic insights into pulmonary tuberculosis.

Growth inhibition and chemo-radiosensitization of head and neck squamous cell carcinoma (HNSCC) by survivin-siRNA lentivirus

BACKGROUND

Survivin expression is often associated with aggressive tumor behavior and therapy resistance. In this study, we investigated the effect of survivin knockdown by survivin-siRNA lentiviral vector (Svv-Lent) on the response of HNSCC to chemo-radiotherapy, tumor growth and metastasis.

METHODS

Four human HNSCC (OSC19, Cal27, Cal33 and FaDu) and one normal HOK cell lines were included in the study, and survivin knockdown was achieved with Svv-Lent treatment. Cell proliferation and apoptosis were measured by MTT and TUNEL assay, respectively. Transwell assays were performed to measure in vitro cell migration and matrigel invasion. Xenograft tumors were developed in nude mice by injecting Cal27 cells subcutaneously and following tail-vein injection of lung and liver metastasis.

RESULTS

Knockdown of survivin significantly suppressed HNSCC cell proliferation and induced apoptosis in vitro. Survivin inhibition could also significantly reduce in vitro cell migration and matrigel invasion that might be due to inactivation of matrix metalloproteinases. In vivo studies showed significant repression of Cal27 xenograft tumor growth and tissue metastasis leading to improvement in mice survival in the Svv-Lent treated group compared to controls. Our data indicated that survivin expression in HNSCC cells contributed to chemo-radioresistance, and its down-regulation increased anti-cancer effects of paclitaxel, cisplatin and radiation.

CONCLUSIONS

Our findings suggest that sustained survivin expression facilitates HNSCC tumor growth and confers resistance to chemo-radiotherapy. Svv-Lent therapy may be able to enhance the cytotoxic effect of commonly used anticancer drugs such as cisplatin and paclitaxel, and radiotherapy that could provide a promising strategy for the effective control of resistant head and neck cancer.

Status of antioxidant and lipid peroxidation in type 2 diabetic human subjects diagnosed with and without metabolic syndrome by using NCEP-ATPIII, IDF and WHO criteria

BACKGROUND

Antioxidants play a very crucial role in terms of disease incidence and its complications. Type 2 diabetes and metabolic syndrome (MetS) are now more prevalent than any other disorder. In this regard this study focuses on type 2 diabetic subjects with MetS having highest incidence of cardiovascular disease. Hence the aim of the study was to reveal the level of antioxidants and lipid peroxidation in MetS and non-MetS groups of type 2 diabetic subjects characterized by three different criteria.

METHODS

Present study was based on 70 type 2 diabetic subjects and 20 healthy controls. The metabolic syndrome criteria were defined by National Cholesterol Education Program (NCEP)-Adult Treatment Panel III (ATPIII), International Diabetes Federation (IDF), and World Health Organization (WHO). The selected subjects were of similar age group. The participants were selected from a diabetic camp being run in the University Campus. The antioxidant enzymes estimated were reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) while Thiobarbituric acid reactive substances (TBARS) measured as a marker of lipid peroxidation.

RESULTS

The level of GSH, CAT, SOD decreases in non-MetS and MetS subjects as compared to normal. When comparison was made for GSH & SOD in the mentioned groups resulted a significant differences in non-MetS and MetS compared with normal subjects. TBARS levels was increased in non-MetS and MetS group of subjects. The results indicate reduction in antioxidant enzymes and elevation of lipid peroxidation in type 2 diabetic subjects with or without MetS defined by using any of the International criteria.

CONCLUSIONS

The study revealed that absolute reduction of antioxidant and involvement of lipid peroxidation in MetS group may lead to progressive intensification of cardiovascular disease in type 2 diabetic subjects irrespective of using any criteria.

Lipid-lowering and antioxidant functions of bottle gourd (Lagenaria siceraria) extract in human dyslipidemia

The study validated the antidyslipidemic, antioxidant, and antihyperglycemic effects of Lagenaria siceraria fruit extract in human subjects with dyslipidemia along with subjects of normal health. A total of 200 mL of freshly prepared Lagenaria siceraria fruit extract was administered daily on empty stomach for 90 days. Significant reductions (P < .01) were found in triglycerides and total cholesterol levels in blood. Cardiac risk ratio, atherogenic coefficient, and atherogenicity index of plasma were also improved. Appreciable reductions in body mass index (P < .01) and blood pressure (systolic P < .01, diastolic P < .05) along with a significant reduction (P < .05) in fasting blood glucose levels were also observed in these subjects. Lagenaria siceraria fruit extract exhibited significant antioxidant activity in dyslipidemic subjects as evident from elevations in SOD (P < .05) and GSH levels (P < .01) with marked improvement in catalase (P < .01) and TBARS levels (P < .05). Phytochemical screening confirmed the presence of saponins, glycosides, flavonoids, terpenoids, and phenolic compounds. Lagenaria siceraria fruit extract serves as dietary adjunct in treatment of human dyslipidemia and cardiovascular disease.

Anti-hyperglycemic and anti-hyperlipidemic potential of a polyherbal preparation "Diabegon" in metabolic syndrome subject with type 2 diabetes

BACKGROUND

In the present study, "Diabegon" a poly-herbal preparation, with hypoglycemic activity, was evaluated for its preventive effect in metabolic syndrome subjects with type 2 diabetes and also to reveal its side effects, on liver and kidney.

MATERIALS AND METHODS

Type 2 diabetic subjects with metabolic syndrome (N=58) were categorized on the basis of age and fasting blood glucose. The grouping was as follows: Group I (35-50 yrs), Group II (51-65 yrs), Group III >65 yrs, Group IV FBS<145.9, Group V FBS>145. Each group was administered 4 gm of diabegon daily. Blood glucose levels, lipid profile, liver and kidney function of the subjects were regularly monitored within 3 months of interval to 18 months.

RESULTS

The reduction in fasting blood glucose level ranged from 12.3% (P<0.05) to 42% (P<0.001) after 18 month of therapy whereas in postprandial blood glucose, the decrease ranged from 28% (P<0.05) to 32% (P<0.05) after 18 month of therapy. Overall reductions in the individual parameters of the metabolic syndrome subjects were significantly higher in Group I. Cholesterol level decreased from 11% to 27.2% (P<0.001), triglyceride levels decreased from 24% to 55%, VLDL and LDL levels reduced by 60% & 54% respectively after 18 months of therapy. The HDL-C level increased in all groups. Moreover, diabegon administration for 1.5 years exhibited no alteration in liver and kidney function tests, which indicate its non-toxicity.

CONCLUSION

Our study suggests that diabegon could be included as a preventive treatment in metabolic syndrome subjects with type 2 diabetes especially for long term treatment as it efficiently shows anti-hyperglycemic and anti-lipidemic effects with no adverse impacts on the liver and kidney.

Efficient ELISA for diagnosis of active tuberculosis employing a cocktail of secretory proteins of Mycobacterium tuberculosis

Rapid and accurate diagnosis is important for preventing transmission of Mycobacterium tuberculosis. Currently available tuberculosis (TB) diagnostic methods lack desired sensitivity and specificity, and require sophisticated equipment and skilled workforce including weeks' long duration to yield results. In this study, extracellular proteins or secretory protein antigens of M. tuberculosis H37Rv have been isolated using ion exchange chromatography, immunocharacterized and exploited for the development of efficient enzyme-linked immunosorbent assay (ELISA) for diagnosis of active TB with enhanced specificity and sensitivity. Apparent molecular masses for purified proteins were found to be 6, 27, 30, 38 and 64 kDa. Out of five purified proteins, one (64 kDa) was found to be novel. Of the five proteins, four (6, 27, 30 and 38 kDa) were found significant to be used in the development of ELISA for pulmonary and extra-pulmonary TB. The immune responses of serum samples of TB patients and other healthy subjects against the above-mentioned antigens' cocktail were evaluated. Critical parameters of newly developed ELISA were optimized and it was observed that the cocktail antigens have a greater specificity (98.06 %) and sensitivity (98.67 %) as compared to other commercially available diagnostic tests. The present findings suggest that the developed ELISA is an effective tool for routine screening and early-stage diagnosis of TB.

Prevalence of metabolic syndrome in type 2 diabetes mellitus using NCEP-ATPIII, IDF and WHO definition and its agreement in Gwalior Chambal region of Central India

The aim of study was to determine the prevalence of metabolic syndrome (MetS) in people with type 2 diabetes mellitus (T2DM). National Cholesterol Education Program (NCEP) ATPIII Criteria, International Diabetes Federation and the World Health Organization (WHO) definitions were used in quantifying the metabolic syndrome and also the concordance between these three criteria's used for identifying metabolic syndrome.

METHODS

This cross-sectional study involved 700 type 2 diabetic subjects from the urban areas of Gwalior Chambal region (Central India). Subjects in the age group of 28- 87 yrs were included in the study. Type I diabetics, pregnant ladies and those with chronic viral and bacterial infections and serious metabolic disorders were excluded from the study. Fasting blood glucose, Blood lipids (T-cholesterol, triglyceride, HDL-cholesterol) were assessed and anthropometry blood pressure were measured from all the subjects.

RESULTS

The Prevalence of metabolic syndrome was found to be 45.8%, 57.7% and 28% following NCEP-ATPIII Criteria, IDF and WHO definitions, respectively. Using all the three definitions the prevalence was higher in women in all age groups. ATP III and IDF criteria showed good agreement (k 0.68) compared to ATP III with WHO (k 0.54) and IDF with WHO (k 0.34) criteria. Highest prevalence was observed following IDF definition.

CONCLUSIONS

A good agreement was observed between ATPIII and IDF criteria. Maximum prevalence of Metabolic syndrome was recorded when IDF criteria was followed. NCEP-ATPIII criteria for the diagnosis of MetS and this criterion reflected equal importance to the every variable and showed a good agreement between the different criteria used.

An omics approach to understand the plant abiotic stress

Abiotic stress can lead to changes in development, productivity, and severe stress and may even threaten survival of plants. Several environmental stresses cause drastic changes in the growth, physiology, and metabolism of plants leading to the increased accumulation of secondary metabolites. As medicinal plants are important sources of drugs, steps are taken to understand the effect of stress on the physiology, biochemistry, genomic, proteomic, and metabolic levels. The molecular responses of plants to abiotic stress are often considered as a complex process. They are mainly based on the modulation of transcriptional activity of stress-related genes. Many genes have been induced under stress conditions. The products of stress-inducible genes protecting against these stresses includes the enzymes responsible for the synthesis of various osmoprotectants. Genetic engineering of tolerance to abiotic stresses help in molecular understanding of pathways induced in response to one or more of the abiotic stresses. Systems biology and virtual experiments allow visualizing and understanding how plants work to overcome abiotic stress. This review discusses the omic approach to understand the plant response to abiotic stress with special emphasis on medicinal plant.

Factors affecting in vitro propagation of Momordica balsamina: a medicinal and nutritional climber

A protocol was developed for multiple shoot induction in a climber with highly medicinal and nutritional values i.e. Momordica balsamina (Cucurbitaceae). Effects of various factors on micropropagation were also studied. Addition of BAP at 1.0 mg/l in MS medium stimulated proliferation of shoots with 6-8 coefficients from the axillary buds. Low concentration of activated charcoal (0.2 %) promoted shoot elongation and reduced callus formation. The combination of 1.0 mg/l BAP and 1.0 mg/l KN promoted shoot elongation and proliferation. NAA proved to be more effective in inducing higher number of roots per shoot than IBA. The plantlets raised in vitro were acclimatized in green house and successfully transplanted to natural condition with 85 % survival. The present investigation showed that direct regeneration of M. balsamina offer a good opportunity to use micropropagation technique as a complementary tool for breeding and other applications.

Lentinus edodes: a macrofungus with pharmacological activities

Lentinus edodes is the first medicinal macrofungus to enter the realm of modern biotechnology. It is the second most popular edible mushroom in the global market which is attributed not only to its nutritional value but also to possible potential for therapeutic applications. Lentinus edodes is used medicinally for diseases involving depressed immune function (including AIDS), cancer, environmental allergies, fungal infection, frequent flu and colds, bronchial inflammation, heart disease, hyperlipidemia (including high blood cholesterol), hypertension, infectious disease, diabetes, hepatitis and regulating urinary inconsistencies. It is the source of several well-studied preparations with proven pharmacological properties, especially the polysaccharide lentinan, eritadenine, shiitake mushroom mycelium, and culture media extracts (LEM, LAP and KS-2). Antibiotic, anti-carcinogenic and antiviral compounds have been isolated intracellularly (fruiting body and mycelia) and extracellularly (culture media). Some of these substances were lentinan, lectins and eritadenine. The aim of this review is to discuss the therapeutic applications of this macrofungus. The potential of this macrofungus is unquestionable in the most important areas of applied biotechnology.

Ganoderma lucidum: a potent pharmacological macrofungus

Ganoderma lucidum (Ling Zhi) is a basidiomycete white rot macrofungus which has been used extensively as "the mushroom of immortality" in China, Japan, Korea and other Asian countries for 2000 years. A great deal of work has been carried out on therapeutic potential of Ganoderma lucidum. The basidiocarp, mycelia and spores of Ganoderma lucidum contain approximately 400 different bioactive compounds, which mainly include triterpenoids, polysaccharides, nucleotides, sterols, steroids, fatty acids, proteins/peptides and trace elements which has been reported to have a number of pharmacological effects including immunomodulation, anti-atherosclerotic, anti-inflammatory, analgesic, chemo-preventive, antitumor, chemo and radio protective, sleep promoting, antibacterial, antiviral (including anti-HIV), hypolipidemic, anti-fibrotic, hepatoprotective, anti-diabetic, anti-androgenic, anti-angiogenic, anti-herpetic, antioxidative and radical-scavenging, anti-aging, hypoglycemic, estrogenic activity and anti-ulcer properties. Ganoderma lucidum has now become recognized as an alternative adjuvant in the treatment of leukemia, carcinoma, hepatitis and diabetes. The macrofungus is very rare in nature rather not sufficient for commercial exploitation for vital therapeutic emergencies, therefore, the cultivation on solid substrates, stationary liquid medium or by submerged cultivation has become an essential aspect to meet the driving force towards the increasing demands in the international market. Present review focuses on the pharmacological aspects, cultivation methods and bioactive metabolites playing a significant role in various therapeutic applications.

Momordica balsamina: a medicinal and neutraceutical plant for health care management

Momordica balsamina, African pumpkin (Cucurbitaceae), is a tendril-bearing, wild climber containing wide spectrum of medicinal and nutritional values and has been used as a traditional folk medicine in many countries. The leaves, fruits, seeds, and bark of the plant contains resins, alkaloids, flavonoids, glycosides, steroids, terpenes, cardiac glycoside, saponins having various medicinal importance viz. anti-HIV, anti-plasmodial, shigellocidal, anti-diarrheal, anti-septic, anti-bacterial, anti-viral, anti-inflammatory, anti-microbial, hypoglycemic, antioxidant, analgesic and hepatoprotective properties. The therapeutic agent 'Momordin' is capable of inhibiting the growth of HIV and other viruses. The leaves are also important source of nutrients having 17 amino acids with adequate mineral composition like potassium, magnesium, phosphorus, calcium, sodium, zinc, manganese and iron. It also helps to combat the problem of micronutrient deficiencies in soil and high value of protein and fat with low fibre content. High potassium content is a good source for the management of hypertension and other cardiovascular conditions. This plant is being promoted as a protein supplement for cereal-based diets in poor rural communities. The commercial exploitation of this plant for biopharmaceuticals and neutraceuticals are some of the prospective future potential of this wild herb. This review discusses the potential of medicinal and nutritional importance of this wild herb for health care management.

Indoor resting density pattern of mosquito species in Fingeswar block of Raipur district in Chhattisgarh, central India

Anopheline mosquitoes are vectors of human malaria and hence they are of greatest concern. Around 40% of the world's population resides in malaria affected areas. Malaria affects poor communities and causes enormous economic losses. The deadly disease annually causes clinical illness in 400-600 million people and kills 2-3 millions annually (WHO 2008). Faunistic survey was conducted in Fingeswar block in Raipur district of Chhattisgarh state of India during January 2003 to March 2004 to asses the prevalence of different species of mosquitoes and their seasonal variations.Indoor resting mosquitoes were collected from selected houses in 5 villages using aspirator tube and torch light in the morning between 06:00-08:00. Adult mosquitoes were identified using standard morphological and pictorial keys following Rao (1984), Das et al. (1991) and Reuben et al. (1994) and assessed as person hour density.A total of 13,248 mosquitoes were collected during the study period. Nine species of mosquitoes comprising of 4 genera with 5 Anopheles, two Culex and one each Armigeres and Aedes were recorded. The malaria vectors constituted 14.09% of the total mosquito collections. Anopheles subpictus (25.81%) showed the dominance followed by A. annularis (8.68%), A. barbirostris (6.76%), A. culicifacies (5.41%) and A. pallidus (4.11%). The other genus recorded included Culex quinquefasciatus (38.38%), C. vishnui (3.32%), Armigeres subalbatus (6.92%) and Aedes albopictus (0.29%). The density of all the species were high in months of August, September and October, decreased in month of May and June 2003. There was a significant (p < 0.01) positive correlation between temperature and density of A. culicifacies and A. annularis. The seasonal distribution pattern of A. culicifacies (primary) and A. annularis (secondary) malaria vectors along with other mosquito species was studied which is an important component of epidemiological study of malaria. This information will help in formulating a baseline structure for control program in the study region.

Impact of season on filarial vector density and infection in Raipur City of Chhattisgarh, India

BACKGROUND & OBJECTIVES

Bionomics and transmission dynamics of vector population are profoundly influenced by local climatic conditions. The study monitored variations in density, infection and infectivity rates of Culex quinquefasciatus with respect to season in randomly selected localities of Raipur City of Chhattisgarh state.

METHODS

The indoor resting density of Cx. quinquefasciatus, Wuchereria bancrofti infection and infectivity rates were monitored in Raipur City at regular monthly intervals for over a period of 12 months and the impact of meteorological conditions on transmission indices were assessed. The frequency distribution of different stages of filarial larvae in naturally infected vector population, host efficiency and transmission intensity index of the vector population was also worked out.

RESULTS

The mean vector density of Cx. quinquefasciatus during the study period was 55.22 while the mean vector infection and infectivity rates recorded in Raipur were 4.05 and 0.25% respectively. A gradual increase in Culex infection rate was recorded from June onwards with a maximum (22.14%) in August and minimum (2.38%) in February. No vector with filarial infection was detected during December when the vector density was high. Analysis of frequency distribution of different stages of larvae revealed dominance of microfilarial stage with a mean larval intensity of 5.37. The highest infectivity rate was observed during June (1.15%) and the lowest was in March (0.41%). Both the infection and infectivity rates were at their low during winter season although the density of Cx. quinquefasciatus was at its maximum. Highest mean host efficiency of 0.44 was recorded in February. The annual transmission intensity index (TII) was 32.72. The highest TII was recorded during January and February months.

INTERPRETATION & CONCLUSION

The climate appeared to have profound impact on vector density, infection and infectivity rates. The vector infection and infectivity rates were high in rainy season followed by summer and winter seasons. The highest host efficiency was observed in winter followed by summer and rainy seasons. An apparent negative correlation was observed between vector infection rate and vector density. Lower temperatures (23-25 degree) with low rainfall favoured progression of mf to L3 in Cx. quinquefasciatus in the study region.

Filarial infection is resisted differentially by subjects having different blood group phenotypes

This study was aimed to elucidate the relationship between major blood group antigens (BGAs) and susceptibility or resistance to human lymphatic filariasis. A total of 492 human subjects, living in Raipur city of Chhattisgarh, endemic for bancroftian filariasis in Central India, were screened for the presence of Wuchereria bancrofti microfilariae and disease manifestations. The frequency of BGAs was tabulated as a function of the status of filariasis, namely normal (no infection), mf carrier (presence of microfilariae in blood), and elephantiasis (confirmed clinical manifestations). The comparison of ABO phenotype distributions among all the three groups clearly indicated that disease status has a significant relationship with the blood group attributes. The result of chi2 analysis of the frequencies of ABO phenotypes observed in microfilaraemic and elephantiasis groups (observed frequency vs. expected frequency computed based on the distribution of the normal population) revealed that there has been a significant alteration in the distribution of ABO phenotypes in microfilaraemic, but not in elephantiasis, group. The susceptibility to filarial infection was computed as a function of blood group phenotypes in the population. The susceptibility and conditional susceptibility for elephantiasis were the least among the subjects with AB phenotypes. The mechanism of association between filariasis and ABO antigens needs to be further explored to understand how the distribution of BGAs affects susceptibility/resistance to infection.

Spirulina in health care management

Spirulina is a photosynthetic, filamentous, spiral-shaped and multicellular edible microbe. It is the nature's richest and most complete source of nutrition. Spirulina has a unique blend of nutrients that no single source can offer. The alga contains a wide spectrum of prophylactic and therapeutic nutrients that include B-complex vitamins, minerals, proteins, gamma-linolenic acid and the super anti-oxidants such as beta-carotene, vitamin E, trace elements and a number of unexplored bioactive compounds. Because of its apparent ability to stimulate whole human physiology, Spirulina exhibits therapeutic functions such as antioxidant, anti-bacterial, antiviral, anticancer, anti-inflammatory, anti-allergic and anti-diabetic and plethora of beneficial functions. Spirulina consumption appears to promote the growth of intestinal micro flora as well. The review discusses the potential of Spirulina in health care management.

Natural bioactive compounds and biotechnological potential of marine bacteria

Adaptation of marine bacteria to the harsh environments has led to a rich biological and genetic diversity. Marine bacteria are attracting attention as new biotechnological resources. These bacteria can be a potential source of new bioactive compounds for industrial, agricultural, environmental, pharmaceutical and medical uses. The present paper reveals the potential of the marine bacteria with biotechnological applications related to antimicrobial drug discovery, environmental remediation, and developing new resources for industrial processes.

Rapid liposomal agglutination card test for the detection of antigens in patients with active tuberculosis

SETTING

A total of 1360 subjects with clinically confirmed pulmonary and extra-pulmonary tuberculosis (TB) and other non-tuberculous conditions.

OBJECTIVES

To develop a rapid, sensitive and specific diagnostic test for the detection of the glycolipid antigen of Mycobacterium tuberculosis in a variety of clinical samples.

STUDY DESIGN

Affinity-purified rabbit anti-glycolipid antibodies (IgG) were coupled to liposome particles (0.2-0.4 microm) in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysuccinamide to prepare the working reagent of the TB/M card test.

RESULTS

Antibody-conjugated liposomes, when determined with the glycolipid antigens present in the specimens, formed a dark blue agglutination within 4 min. No clumping was observed in samples from normal healthy subjects or patients with other diseases. The test was shown to be effective in detecting glycolipid antigens of M. tuberculosis in clinical samples from patients with active TB with as low as 1 ng/ml analytical sensitivity, 97.4% clinical sensitivity and 96.9% specificity.

CONCLUSION

The TB/M card test was found to be comparatively economical (4 Indian Rupees or US$ 0.09/test), rapid (4 min) and seems fairly useful for mass testing of a variety of biological specimens (cerebrospinal, pleural and synovial fluids, serum, tissue biopsy extract) from patients with tuberculous meningitis, pulmonary TB and other extra-pulmonary TB in endemic countries.

Physiological and biochemical alterations in a diazotrophic cyanobacterium Anabaena cylindrica under NaCl stress

Growth, morphological variation, and liquid chromatography-photodiode array detection-mass spectrometric analysis of pigments have been studied in a diazotrophic cyanobacterium Anabaena cylindrica in response to NaCl stress. The chlorophyll and cellular protein contents increased initially in response to 50 mM: NaCl. Further increment in NaCl concentration, however, resulted in a significant decrease in both chlorophyll and cellular protein. A. cylindrica cells subjected to NaCl stress also showed morphological variations by having alteration in their size and volume. A. cylindrica cells subjected to NaCl stress also exhibited altered plastoquinone and chlorophyll-a (chl a) levels in comparison to its NaCl-untreated counterpart. Furthermore, a relative increase in plastoquinone level and a subsequent decrease in chl a level were recorded in NaCl adapted cells of A. cylindrica in response to NaCl stress. These results suggest that owing to adaptation various morphological, physiological, and biochemical changes occur in the cyanobacterium A. cylindrica in response to NaCl stress.

Subjects with Impaired Glucose Tolerance Exhibit a High Degree of Tolerance to Honey

The present study compared the relative tolerance to honey and glucose of subjects with impaired glucose tolerance or mild diabetes. Thirty individuals 35-60 years old with a proven parental (mother or father) history of type II diabetes mellitus were subjected simultaneously to an oral glucose tolerance test (GTT) and a honey tolerance test (HTT). Glucose tolerance was found to be impaired in 24 subjects, while six of the subjects were diagnosed as mildly diabetic. All subjects with impaired glucose tolerance exhibited significantly lower plasma glucose concentrations after consumption of honey at all time points of the HTT in comparison to the GTT. The plasma glucose levels in response to honey peaked at 30-60 minutes and showed a rapid decline as compared to that to glucose. Significantly, the high degree of tolerance to honey was recorded in subjects with diabetes as well, indicating a lower glycemic index of honey. Thus, it is evident from the present investigation that honey may prove to be a valuable sugar substitute for subjects with impaired glucose tolerance or mild diabetes.

Iron mediated regulation of growth and siderophore production in a diazotrophic cyanobacterium Anabaena cylindrica

Iron mediated regulation of growth and siderophore production has been studied in a diazotrophic cyanobacterium Anabaena cylindrica. Iron-starved cells of A. cylindrica exhibited reduced growth (30%) when the cells were growing under N2-fixing conditions. In contrast, N03-, NO2-, NH4' and urea grown cells exhibited almost 50% reduction in their growth in the absence of iron as compared to their respective counterparts cultured in the presence of iron. However, at 60 microM of iron, A. cylindrica cells exhibited almost equal growth regardless of the nitrogen source available. Siderophore production in A. cylindrica was started after day 2nd of the cell growth and attained its optimal level on day 5th when the cells were at their mid-log phase. No siderophore production was, however, recorded on day 2nd at all the concentrations of iron tested. The production of siderophore in A. cylindrica further increased with increase in iron concentration and attained its optimum level on day 5th at 60 microM iron. A. cylindrica cells took at least 3 days for initiation of siderophore production and produced about 60% siderophore on day 5th even under iron-starved condition. A. cylindrica produced dihydroxamate type of siderophore.

Iron induced metabolic changes in the diazotrophic cyanobacterium Anabaena PCC 7120

Iron induced changes in growth, N2-fixation, CO2 fixation and photosynthetic activity were studied in a diazotrophic cyanobacterium Anabaena PCC 7120. Iron at 50 microM concentration supported the maximum growth, heterocyst frequency, CO2 fixation, photosystem I (PS I), photosystem II (PS II) and nitrogenase activities in the organism. Higher concentration of iron inhibited these processes. Chl a and PS II activities were more sensitive to iron than the protein and PS I activity.

Structural, functional and therapeutic biology of survivin

Survivin is a unique member of the inhibitor of apoptosis (IAP) protein family that interferes with post-mitochondrial events including activation of caspases. Survivin regulates cell cycle also. It is expressed in most of the human tumors, but it is barely detectable in the terminally differentiated normal cells/tissues. Molecular mechanisms of regulation of survivin in cancer are not clearly understood. Nevertheless, the functional loss of wild type p53 is often associated with upregulation of survivin. Tumors that over-express survivin generally bear a poor prognosis and are associated with resistance to therapy. The differential expression of survivin in cancer versus normal tissues makes it a useful tool in cancer diagnosis and a promising therapeutic target. A growing body of literature suggests nuclear expression of survivin as a good prognostic marker. Disruption of the survivin induction pathway has resulted in an increase in apoptosis and inhibition of tumor growth. Regular therapies, such as, radiotherapy in combination with anticancer drugs in clinical practice may yield promising results.

Micropropagation: a tool for the production of high quality plant-based medicines

Medicinal plants are the most important source of life saving drugs for the majority of the world's population. The biotechnological tools are important to select, multiply and conserve the critical genotypes of medicinal plants. Plant tissue culture techniques offer an integrated approach for the production of standardized quality phytopharmaceutical through mass-production of consistent plant material for physiological characterization and analysis of active ingredients. Micropropagation protocols for cloning of some medicinal plants such as Catharanthus roseus (Apocynaceae), Chlorophytum borivilianum (Liliaceae), Datura metel (Solanaceae), and Bacopa monnieri (Scrophulariaceae) have been developed. Regeneration occurred via organogenesis and embryogenesis in response to auxins and cytokinins. The integrated approaches of our culture systems will provide the basis for the future development of novel, safe, effective, and high-quality products for consumers.

Nutritional and therapeutic potential of Spirulina

Spirulina, a filamentous cyanobacterium, possesses diverse biological activities and nutritional significance due to high concentration of natural nutrients, having bio-modulatory and immuno-modulatory functions. Different Spirulina preparations influence immune system viz. increase phagocytic activity of macrophages, stimulating the production of antibodies and cytokines, increase accumulation of NK cells into tissue and activation and mobilization of T and B cells. Spirulina have also shown to perform regulatory role on lipid and carbohydrate metabolism by exhibiting glucose and lipid profile correcting activity in experimental animals and in diabetic patients. Preparations have been found to be active against several enveloped viruses including herpes virus, cytomegalovirus, influenza virus and HIV. They are capable to inhibit carcinogenesis due to anti-oxidant properties that protect tissues and also reduce toxicity of liver, kidney and testes.

Physiological and biochemical alterations in Anabaena 7120 under iron stress

Various physiological and biochemical process like growth, NO3- -uptake, nitrate reductase, glutamine synthetase and ATPases (Mg2+ and Ca2+ dependent) in the cyanobacterium Anabaena 7120 were observed under iron stress. Growth was found to be maximum in 50 microM Fe3+ added cells however, 20 microM Fe3+ (the Fe3+ concentration generally used for routine culturing of cyanobacterial cell in Chu 10 medium) incubation resulted in lower growth. Fe3+ starvation on the other hand showed very poor growth up to 4th day but once the growth started it reached at significant level on 7th day. Higher Fe3+ concentration reflected reduced growth with lethality at 500 microM Fe3+. Chlorophyll a fluorescence under Fe3+ stress reflected almost the similar results as in case of growth. However, the pigment was found to be more sensitive as compared to protein under Fe3+ stress. Similar results have been observed in case of NO3-uptake with only 80% reduction in nutrient uptake in 500 microM Fe3+ incubated cells. Nitrate reductase activity was lower in Fe3+ starved cells as compared to significant enzyme activity in 20 and 50 microM Fe3+ incubated cells. Similar to nitrate reductase, glutamine synthetase also showed maximum level in 50 microM Fe3+ added cells, however, higher Fe3+ concentration (300-500 microM ) resulted in reduced enzymatic activity. Glutamine synthetase activity was less sensitivity as compared to nitrate reductase activity under Fe3+ stress. ATPase (Mg2+ and Ca2+ dependent) always showed higher level with increasing Fe3+ concentration.

Isolation and partial characterization of Het- Fix- mutant strain of the diazotrophic cyanobacterium Anabaena variabilis showing chromatic adaptation

We propose a model to describe the changes taking place in biochemical processes/events to explain the development of heterocyst and nitrogenase in a diazotrophic cyanobacterium Anabaena variabilis. For this purpose, a mutant strain of A. variabilis lacking heterocyst differentiation and incapable of growth with dinitrogen as the sole source of nitrogen has been isolated after nitrosoguanidine (NTG) mutagenesis and selection by penicillin enrichment. The mutant strain (Het- Fix-) thus isolated has morphological variation and was incapable of reducing acetylene under anaerobic conditions, indicating its mutational loss of the process of nitrogen fixation. The Het- Fix- mutant strain had reduced glutamine synthetase (transferase) activity compared with its wild-type counterpart, suggesting a link between nif gene expression and the expression of gln A, the structural gene of GS. The Het- Fix- mutant strain compared with its wild-type strain also had an extremely high level of phycobiliprotein and a low level of carotenoids. Furthermore, the coiling of vegetative filaments in the Het- Fix- mutant strain, which reduced the surface area to be exposed to light, was a direct indication of the chromatic adaptation, because the mutant strain was found to be photosensitive, showing bleaching of the cells under high light intensity.

Regulation of sodium influx in the NaCl-resistant (NaCl(r)) mutant strain of the cyanobacterium Anabaena variabilis

A NaCl(r) mutant of the diazotrophic cyanobacterium Anabaena variabilis has been isolated by NTG mutagenesis and selection for NaCl resistance. The NaCl(r) strain has been characterized with respect to its mechanism of NaCl tolerance and regulation of Na(+) influx. NaCl(r) strain exhibits low Na(+) influx, accumulated high level of glycine betaine as a compatible solute, and persistent synthesis of SSPs at a higher rate than its wild-type counterpart. DCMU, an inhibitor of PS-II, inhibited Na(+) influx, suggesting that Na(+) influx is an energy-dependent process and that the energy is derived from photophosphorylation. This contention is further supported by the inhibition of Na(+) influx under dark conditions. The inhibition of Na(+) influx by KCN, DNP, NaN(3) also supports the involvement of oxidative phosphorylation in the regulation of active Na(+) influx. Thus, it appears that the synthesis of SSPs, accumulation of compatible solutes, and exhibition of low Na(+) influx in the NaCl(r) strain made this organism NaCl tolerant.

Valine 77 of heterocystous ferredoxin FdxH2 in Anabaena variabilis strain ATCC 29413 is critical for its oxygen sensitivity

Ferredoxins are small iron sulfur proteins necessary for electron donation. FdxH1 and FdxH2 are associated with two different nif gene clusters where they transfer electrons for the reduction of nitrogenase complex. FdxH1 was observed to be stable towards oxygen, whereas, FdxH2 was relatively unstable. We had identified the amino acid involved in oxygen sensitivity of ferredoxin protein using protein modeling. The exchange of valine to leucine at position 77 was critical for ferredoxin proteins in relation to its oxygen sensitivity. This exchange leads to a longer side chain, which inhibits the accessibility of oxygen to the iron sulfur cluster. Site directed mutagenesis and in vitro experiments confirms that valine indeed is involved in the oxygen sensitivity. The exchange of leucine to valine in FdxH1 makes it oxygen unstable. Thus, from the above results we can conclude that the position of leucine at position 77 is critical for oxygen sensitivity of ferredoxin and protein modeling can be used to identify specific amino acids in other oxygen-sensitive proteins.

Isolation and characterization of the thylakoid membranes from the NaCl-resistant (NaCl(r)) mutant strain of the cyanobacterium Anabaena variabilis

NaCl-induced changes in the thylakoid membrane of wild-type Anabaena variabilis and its NaCl(r) mutant strain have been studied. Biochemical characterization of the thylakoid membrane was done by taking its absorption and fluorescence spectra at different wavelength. The thylakoid membranes of both strains were isolated by mechanical disruption of the freeze-dried and lysozyme-treated cells, followed by differential and density gradient centrifugation. The light absorption spectra of the thylakoid membrane showed three and two peaks in NaCl(r) mutant strain and its wild-type counterpart respectively at wavelengths of 400-850 nm. These peaks revealed that the thylakoid membrane contains a large amount of carotenoid and chlorophyll a. Fluorescence emission spectra of thylakoid membrane of NaCl(r) mutant and its wild-type strain at excitation wavelength of 335 nm showed two different peaks, one at 340 nm and the other at 663 nm respectively. The light absorption and fluorescence spectra of the thylakoid membrane also revealed that the membrane contained carotenoid pigment, chlorophyll (Chl) a, and a pigment with an emission peak at 335 nm. The HPLC analysis of the pigments of the thylakoid membrane indicates that the NaCl(r) mutant strain under NaCl stress contained an additional peak for the carotenoid pigment, which was lacking in its wild-type counterpart. The major peak in thylakoid membrane was that of echinenone and beta-carotene. Whereas the polypeptide composition of thylakoid membrane differed in the wild-type and its NaCl(r) mutant strain, no difference in the cell wall protein pattern was observed in both strains. The thylakoid membrane of NaCl(r) mutant strain contained two additional protein bands that were absent in its wild-type counterpart. The thylakoid membrane of the wild-type and its NaCl(r) mutant strain also showed morphological variations under NaCl stress.

Identification of amino acids responsible for the oxygen sensitivity of ferredoxins from Anabaena variabilis using site-directed mutagenesis

The filamentous cyanobacterium Anabaena variabilis (ATCC 29413) possesses two molybdenum dependent nitrogenase systems, nif1 and nif2. The nif1 system is regulated by a developmental program involving heterocyst differentiation; the nif2 system is expressed in all cells only under anaerobic conditions and the expression is controlled environmentally. The genes fdxH1 and fdxH2, encoding two [2Fe-2S] ferredoxins, are part of the these two distinct and differently regulated nif gene clusters. The sensitivity of both ferredoxins to oxygen was different; the half-life of FdxH2 in air was only approximately 1.5 h, while FdxH1 retained 80% of its nitrogenase activity after 24 h. We used site-directed mutagenesis to identify the role of individual amino acid residues responsible for oxygen sensitivity and found out that the FdxH2 double mutant I76A/V77L was much more resistant to oxygen than the wild-type ferredoxin (FdxH2) and similar to FdxH1. By modelling it was shown that the accessibility of the cavity around the iron-sulfur cluster was responsible for that.

Calcium-dependent metabolic regulations in prokaryotes indicate conserved nature of calmodulin gene

Role of free calcium and calcium binding protein calmodulin as signal molecule in cellular regulation is well established in eukaryotes. However, reports on Ca(2+)-dependent processes and their inhibition by calcium and/or calmodulin antagonists indicate towards the presence of calmodulin in prokaryotes as well. The common evolutionary origin of pro- and eukaryotes and many examples of evolutionary conservation of structure and functions support the contention of such conservation of the role of Ca2+ and calmodulin. Eukaryotic calmodulin (CaM) contains four structurally and functionally similar Ca2+ domains named I, II, III and IV. Each Ca2+ binding loop consists of 12 amino acid residues with ligands arranged spatially to satisfy the octahedral symmetry of Ca2+ binding. Plant calmodulin differ from vertebrate ones in 13 to 14 amino acid positions of which nine occur at -COOH- terminal half. Differences between protozoan and mammalian CaM also occur mostly in the same half. Isolation and characterization, although to a little extent, of CaM-like proteins from bacteria and cyanobacteria and their comparison with CaMs from diverse origin suggest high degree of conservation. Non-bulky amino acids like glycine, alanine and serine with low specific rotation are present in greater number in the primitive form of calmodulin and have been significantly reduced in highly evolved form of calmodulin, suggesting that their requirement was insignificant and were eliminated from EF hand structure during evolution. However, amino acids like glutamate/glutamine and aspartate/asparagine were highly conserved and did not show any major change in their frequency since their positions are too significant in calcium binding domain. While the number of positively charged amino acids like arginine and leucine was increased, histidine containing weakly ionized group and having a significant buffering capacity was reduced to a major extent, further suggesting that the acidic nature of calmodulin protein has been maintained during evolution. Thus it is now clear that the entire superfamily of Ca2+ binding proteins have arisen from a common genetic ancestry. Two successive tandem duplications of gene encoding a single domain containing protein of 30-40 residues gave rise to a four domain molecule from which this family was then derived.

Phytolectins: natural molecules with immense biotechnological potential

Lectins are structurally diverse, carbohydrate binding proteins that bind reversibly to specific mono- or oligosaccharides. Their abundance in the plant kingdom suggest that they have diverse roles to perform. They serve as recognition factor between symbiotic nitrogen fixing bacteria and host plants, as a deterrent to phytopathogens like fungi, insects, and animals, as storage protein and as an aid in sexual reproduction in Chlamydomonas, amongst others. The possible application of lectins as a factor in increasing soil fertility and as a biopesticide by genetically engineered organisms is yet to be fully explored by the biotechnologists. However, they are being used by the biomedical scientists and biochemists in blood typing and stimulation of cells for chromosome analysis and gene mapping, in cell separation, identification of complex glycoproteins and typing of bacteria. Cell targeting by lectins in cancer therapy is still in its infancy. This review gives an insight into the potential of these wonder biomolecules in agriculture, biochemistry, cell biology and medicine for the benefit of mankind.

Copper-induced changes in the urea uptake and urease activity in the cyanobacteria Anabaena doliolum and Anacystis nidulans: interaction with sulphur containing amino acids

Copper-induced changes in the urea uptake and urease activity have been investigated in the cyanobacteria Anabaena doliolum and Anacystis nidulans. Copper, at and above 5 mumol/L concentration, inhibited urea uptake and urease activity systems in both the cyanobacteria in a concentration dependent manner. However, the urea uptake and urease activity systems in A. nidulans appeared slightly more tolerant to copper than than of A. doliolum. The inhibitory effect of copper on urea uptake and urease activity was mitigated by sulphur containing amino acids (cystine and cysteine), however, methionine could not do so, indicating the involvement of sulfhydryl (-SH) groups in the assimilation of urea in cyanobacteria.

Glutamine synthetase and arginine inhibition of nitrate reductase activity in Anabaena cycadeae

Wild-type Anabaena cycadeae with normal glutamine synthetase (GS) activity utilized arginine as sole N source whereas a mutant strain lacking GS activity did not. Nitrate reductase (NR) activity, higher in the mutant strain than the wild-type strain, was inhibited by arginine though arginine-dependent NH 4 (+) generation was higher in the mutant strain than in the wild-type. This suggests that (1) NR activity is NO inf3 (sup-) -inducible and arginine-repressible; and (2) while GS activity is required for the assimilation of arginine as sole N-source, it is not required for arginine inhibition of NR activity.

Adaptive response of wild and mutant type Synechococcus cedrorum to a polychlorinated pesticide-endosulfan

The effect of endosulfan, a hexachlorinated pesticide, on growth, inorganic nitrogenous nutrient uptake (NO3-, NO2- and NH4+), change in pigmentation and glycogen content on wild type and chemically mutagenised cells of Synechococcus cedrorum was investigated. The pattern of response to pesticide stress in wild and mutant type was the same. Growth reappeared in both after a period of initial lag in presence of endosulfan. The duration of lag increased with increasing doses of pesticide. Paradoxically, however, the rate of uptake of NO3-, NO2- and NH4+, pigment and glycogen content progressively increased with increasing doses. The difference in the adaptation response between wild and mutant types was observed only in the concentration of pesticide that could be tolerated; with the mutant tolerating 2.5 fold more.

Isolation and physiological characterization of Synechococcus cedrorum 1191 strain tolerant to heavy metals and pesticides

The toxicity of heavy metals (Hg2+, Zn2+) and pesticides has been investigated by comparing the physiological properties in wild and tolerant strains of Synechococcus cedrorum 1191. The differential pattern of growth, absorption spectra of pigments and nutrient uptake was observed in tolerant strain.

Demonstration of an altered phenylalanyl-tRNA synthetase in an analogue-resistant mutant of Aspergillus nidulans

We have isolated and characterized a new class of p-fluorophenylalanine (FPA)-resistant mutant in Aspergillus nidulans using a phenA strain as the wild type, by optimizing the conditions of growth. All four spontaneous mutants selected on a medium containing FPA were found to be recessive to their wild-type alleles in heterozygous diploids. Complementation analyses and linkage data showed that they were allelic and mapped at a single locus (fpaU) in the facA-riboD interval on the right arm of linkage group V. Partial purification and characterization of Phe-tRNA synthetase from wild-type and mutant strains revealed that the mutant enzyme had a greatly reduced ability to activate the analogue. It is suggested that mutation in the fpaU gene brings about a structural alteration in Phe-tRNA synthetase.