Distillery effluent as a potential medium for bacterial cellulose production: A biopolymer of great commercial importance

In the present study, an attempt was made to utilize the distillery effluent for the production of bacterial cellulose by a novel bacterial species, Gluconacetobacter oboediens. Maximum bacterial cellulose production of 0.85g/100ml was achieved in crude distillery effluent. The production was successfully scaled up to 1.0L size producing 8.1g of bacterial cellulose. Morphological, structural and thermal characterization of purified bacterial cellulose by SEM, FT-IR and TGA analysis showed that it is pure cellulose having good properties. Henceforth, the present study proved a concept that distillery effluent could be utilized for the production of bacterial cellulose, a biopolymer of immense importance, which in turn may be used for producing different value added products.

Phototrophic cultivation of NaCl-tolerant mutant of Spirulina platensis for enhanced C-phycocyanin production under optimized culture conditions and its dynamic modeling

Commercial cultivation of Spirulina sp. is highly popular due to the presence of high amount of C-phycocyanin (C-PC) and other valuable chemicals like carotenoids and γ-linolenic acid. In this study, the pH and the concentrations of nitrogen and carbon source were manipulated to achieve improved cell growth and C-PC production in NaCl-tolerant mutant of Spirulina platensis. In this study, highest C-PC (147 mg · L^-1 ) and biomass (2.83 g · L^-1 ) production was achieved when a NaCl-tolerant mutant of S. platensis was cultivated in a nitrate and bicarbonate sufficient medium (40 and 60 mM, respectively) at pH 9.0 under phototrophic conditions. Kinetic study of wildtype S. platensis and its NaCl-tolerant mutant was also done to determine optimum nitrate concentrations for maximum growth and C-PC production. Kinetic parameter of inhibition (Haldane model) was fitted to the relationship between specific growth rate and substrate concentration obtained from the growth curves. Results showed that the maximum specific growth rate (μ_max ) for NaCl-tolerant mutant increased by 17.94% as compared to its wildtype counterpart, with a slight increase in half-saturation constant (K_s ), indicating that this strain could grow well at high concentration of NaNO₃ . C-PC production rate (C_max ) in mutant cells increased by 12.2% at almost half the value of K_s as compared to its wildtype counterpart. Moreover, the inhibition constant (K_i ) value was 207.85% higher in NaCl-tolerant mutant as compared to its wildtype strain, suggesting its ability to produce C-PC even at high concentrations of NaNO₃ .

Shikimic acid, a base compound for the formulation of swine/avian flu drug: statistical optimization, fed-batch and scale up studies along with its application as an antibacterial agent

The sudden outbreak of swine flu has increased the global demand of shikimic acid which is an industrially interesting compound, as it is used as a key starting material for the synthesis of a neuraminidase inhibitor Tamiflu(®), for the treatment of antiviral infections such as swine flu. Statistical optimization and evaluation of medium components for the production of shikimic acid by Citrobacter freundii is addressed in the present investigation. Plackett-Burman design was applied for the screening of the most significant variables affecting shikimic acid production, where glucose, asparagine, KH2PO4, CaCO3 and agitation rate were the most significant factors. Response surface methodology was also employed to study the interaction among the most significant variables through which shikimic acid production increased to 12.76 g/L. Further, fed-batch studies resulted in the production of 22.32 g/L of shikimic acid. The scalability of the process was also confirmed by running 14 L bioreactor (7.5 L production medium) where 20.12 g/L of shikimic acid was produced. In addition the antibacterial activity of the shikimic acid produced was analysed against four Gram positive and four Gram negative bacteria and it was found to have a greater inhibition effect against the Gram negative bacteria.

Dual substrate strategy to enhance butanol production using high cell inoculum and its efficient recovery by pervaporation

The present study deals with the development of an efficient ABE fermentation process using mixed substrate strategy for butanol production wherein no acetone was produced. For this, glucose was supplemented in the medium containing glycerol as main substrate which leads to a higher butanol production of 17.75 g/L in 72 h by Clostridium acetobutylicum KF158795. Moreover, the high cell inoculum also resulted in an increased ABE productivity of 0.46 g/L/h. Further, industrial scalability of the process was also successfully validated in a 300 L fermenter. Furthermore, potential of the Polymeric (PolyRMem) and Zeolite (ZeoMem) membranes for separation of butanol from fermentation broth was also studied by testing the pervaporation performance through which the butanol was successfully recovered.

An interactive study of influential parameters for shikimic acid production using statistical approach, scale up and its inhibitory action on different lipases

Shikimic acid is the promising candidate as a building block for the industrial synthesis of drug Tamiflu used for the treatment of Swine flu. The fermentative production process using microbes present an excellent and even more sustainable alternative to the traditional plants based extraction methods. In the present study, the fermentative production of shikimic acid by Citrobacter freundii GR-21 (KC466031) was optimized by process engineering using a statistical modeling approach and a maximum amount of 16.78 g L(-1) was achieved. The process was also scaled up to 14L bioreactor to validate the production of shikimic acid. Further, the potential of anti-enzymatic nature of purified shikimic acid was evaluated for different lipases wherein, shikimic acid inhibited the hydrolysis of triglycerides by 55-60%. Shikimic acid also profoundly inhibited pancreatic lipase activity by 66%, thus providing another valuable therapeutic aspect for treating diet induced obesity in humans.

Effect of arbuscular mycorrhizal inoculations on seedling growth and biomass productivity of two bamboo species

A study was conducted to identify suitable arbuscular mycorrhizal (AM) fungi for inoculation of Bambusa bambos and Dendrocalamus strictus at nursery stage for increasing growth and productivity. Twelve AM species, isolated from bamboo and other common trees of Bundelkhand were used for inoculations. In B. bambos, total dry weight and phosphorus (P) uptake were significantly increased by all studied fungi and shoot length was increased by eight AM inoculants. Maximum mycorrhizal dependency (MD) was recorded for Acaulospora scrobiculata (44.2%), followed by Glomus cerebriforme (41.6%) and G. intraradix (41.0%). In D. strictus, all tested AM inoculants significantly increased shoot length, dry shoot weight and P uptake, except Glomus 1. Dry root weight was significantly increased by only two inoculants namely, G. cerebriforme and G. etunicatum. Total dry weight was significantly increased by eight AM fungi. Maximum MD was recorded for G. cerebriforme (62.9%), followed by G. diaphanum (55.0%) and G. etunicatum (51.3%). Thus, the results showed that utilization of effective AM fungi can enhance the productivity of bamboo in the region.

Expanding horizons of shikimic acid. Recent progresses in production and its endless frontiers in application and market trends

Shikimic acid is an industrially important chiral compound used as a key ingredient in formulation of drug Oseltamivir phosphate (Tamiflu) for the treatment of swine/avian flu. The high cost and limited availability of shikimic acid isolated from plants has detained the use of this valuable building block of the drug. It is a versatile compound having many characteristic properties for many synthetic reactions particularly in pharmaceuticals and cosmetic industries. By virtue of being a natural product, the relevant biochemical pathway in microorganisms can be harnessed into fermentation processes to produce shikimic acid. This is an excellent alternative for the sustainable and efficient production of shikimic acid over the tedious and cumbersome process of plant based extraction methods. Various strategies of shikimic acid production are reviewed and an account of comparison of their challenges, promises and restraint is presented. Furthermore, present review attempts to focus on the market trend of shikimic acid due to its high demand with particular emphasis laid on the pandemics of swine flu. This review not only covers the recent advances in shikimic acid production but also highlights the versatile applications and its market scenario. The concluding remarks and its potential as a commercial bulk chemical are discussed in the light of current research.

Fermentative production of shikimic acid: a paradigm shift of production concept from plant route to microbial route

Different physiological and nutritional parameters affect the fermentative production of shikimic acid. In our study, Citrobacter freundii initially produced 0.62 g/L of shikimic acid in 72 h. However, when process optimization was employed, 5.11 g/L of shikimic acid was produced in the production medium consisting of glucose (5.0 %), asparagine (4.5 %), CaCO3 (2.0 %), at pH 6.0, when inoculated with 6 % inoculum and incubated at 30 ± 1 °C, 200 rpm for 60 h. Preliminary fed-batch studies have resulted in the production of 9.11 g/L of shikimic acid on feeding the production medium by 20 g/L of glucose at 24 h of the fermentation run. Production of similar amount of shikimic acid was observed when the optimized conditions were employed in a 10-L bioreactor as obtained in shake flask conditions. A total of 9.11 g/L of shikimic acid was produced in 60 h. This is approximately 14.69-fold increase in shikimic acid production when compared to the initial un-optimized production conditions. This has also resulted in the reduction of the production time. The present study provides useful information to the industrialists seeking environmentally benign technology for the production of bulk biomolecules through manipulation of various chemical parameters.

Efficient production of L-asparaginase from Bacillus licheniformis with low-glutaminase activity: optimization, scale up and acrylamide degradation studies

L-Asparaginase has potential as an anti-cancer drug and for prevention of acrylamide formation in fried and baked foods. Production of the enzyme by Bacillus licheniformis (RAM-8) was optimized by process engineering using a statistical modeling approach and a maximum yield of 32.26 IU/ml was achieved. The L-asparaginase exhibited glutaminase activity of only 0.8 IU/ml and would therefore be less prone to cause the side effects associated with asparaginase therapy compared to enzyme preparations with higher glutaminase activities. When production was carried out in a 30-L bioreactor, enzyme production reached 29.94 IU/ml in 15 h. The enzyme inhibited poly-acrylamide formation in 10% acrylamide solution and reduced acrylamide formation in fried potatoes by 80%.

Retained foreign body in sino-orbital region

It is rare to find foreign bodies in nose and paranasal sinuses. The further rarity is to encounter impacted foreign body in this region and route of entry being through the orbit. We are here by presenting a case, where a metallic foreign body was retained for duration of 4 months in sino - orbital region.

Haemorrhagic cystic sino-nasal fibrous dysplasia

A 9 years old boy reported with left nasal blockage, occasional left nasal bleeding, protruding left eye ball and widening of the nasal bridge for the last nine months. Clinical examination and radiological evaluation were suggeitive of fibrous dysplasia. Mass was excised by transfacial and transcranial approach. Histopathology of the excised muns proved to be a case of haemorrhagic cystic sino-nasal fibrous dysplasia.

Fermentation behavior of osmophilic yeast Candida tropicalis isolated from the nectar of Hibiscus rosa sinensis flowers for xylitol production

Eighteen yeast species belonging to seven genera were isolated from ten samples of nectar from Hibiscus rosa sinensis and investigated for xylitol production using D-xylose as sole carbon source. Amongst these isolates, no. 10 was selected as the best xylitol producer and identified as Candida tropicalis on the basis of morphological, biochemical and 26S rDNA sequencing. C. tropicalis produced 12.11 gl(-1) of xylitol in presence of 50 gl(-1) of xylose in 72 h at pH 5, 30°C and 200 rpm. The strain of C. tropicalis obtained through xylose enrichment technique has resulted in a yield of 0.5 gg(-1) with a xylitol volumetric productivity of 1.07 gl(-1)h(-1) in the presence of 300 gl(-1) of xylose through batch fermentation. This organism has been reported for the first time from Hibiscus rosa sinensis flowers. Realizing, the importance of this high valued compound, as a sugar substitute, xylose enrichment technique was developed in order to utilize even higher concentrations of xylose as substrate for maximum xylitol production.

Expression, purification and characterization of allelic variants of MSP-1(42) from Indian Plasmodium falciparum isolates

The C-terminal 19 and 42 kDa fragments of Plasmodium falciparum merozoite surface protein 1 (MSP-1) have shown to be protective in animals against lethal parasite challenge. The MSP-1(19) being highly conserved may lack sufficient number of T-cell epitopes in order to elicit a broader response in genetically diverse populations. The inclusion of additional epitopes from the N-terminal MSP-1(42) has shown to enhance the protective efficacy of MSP-1(19) vaccine. In an attempt to examine the strain specific immunogenicity to MSP-1, we have cloned and expressed three diverse allelic variants of MSP-1(42) from Indian P. falciparum isolates in bacteria. Among three alleles, one was extremely rare and not been found before. These purified and refolded recombinant products were recognized by conformation specific monoclonal antibodies and hyper-immune sera. Immunization of mice and rabbits with the purified proteins generated high titer biologically active polyclonal antibodies supporting further development of this vaccine candidate antigen.

Amphotericin B--fat emulsion in treatment of visceral leishmaniasis--a cost effective substitute for liposomal amphotericin B

In spite of high dosage and prolonged treatment schedule of sodium antimony gluconate, unresponsiveness and relapse ranging from 25 to 40% has been reported. The cure rate of 90 to 92.9% with amphotericin B-fat emulsion is comparable to that with liposomal amphotericin B (80 to 100%). Due to high cost liposomal amphotericin B is beyond the reach of most of the Indian patients, whereas the cost of treatment with amphotericin B-fat emulsion is quite affordable. Further large scale studies with amphotericin B-fat emulsion are required to evaluate its effectiveness in Indian kala-azar patients and to establish its optimal dose.

Characterization of cross-linked immobilized lipase from thermophilic mould Thermomyces lanuginosa using glutaraldehyde

Cross-linked enzyme aggregates (CLEAs) have emerged as an interesting biocatalyst design for immobilization. Using this approach, a 1,3 regiospecific, alkaline and thermostable lipase from Thermomyces lanuginosa was immobilized. Efficient cross-linking was observed when ammonium sulphate was used as precipitant along with a two fold increase in activity in presence of SDS. The TEM and SEM microphotographs of the CLEAs formed reveal that the enzyme aggregates are larger in size as compared to the free lipase due to the cross-linking of enzyme aggregates with glutaraldehyde. The stability and reusability of the CLEA with respect to olive oil hydrolysis was evaluated. The CLEA showed more than 90% residual activity even after 10 cycles of repeated use.

Immunogenicity of a recombinant malaria vaccine candidate, domain I+II of AMA-1 ectodomain, from Indian P. falciparum alleles

Among the few vaccine candidates under development, apical membrane antigen (AMA-1) of Plasmodium falciparum is one of the most promising erythrocyte stage malaria vaccine candidates under consideration. The overall structure of AMA-1 appears to be conserved as compared to other surface proteins, but there are numerous amino acid substitutions identified among different P. falciparum isolates. Antisera raised against recombinant AMA-1 or naturally acquired human antibodies were strongly inhibitory only towards homologous parasites. In an attempt to examine the strain specificity of antibodies elicited to AMA-1, we have cloned, expressed and purified two allelic variants of domain I+II of AMA-1 ectodomain from Indian P. falciparum isolates in bacteria. One of these is a new haplotype not reported so far and varies in 18 aa positions from the geographically diverse forms 3D7 and 15 from FVO. Refolded proteins were recognized by a conformation specific monoclonal antibody 4G2.dc1 and hyper immune sera. Immunization of mice and rabbits with the purified proteins using CFA/IFA adjuvant generated high titer polyclonal antibodies. Both the alleles induced high levels of IgG1, IgG2a and IgG2b and a low level of IgG3 in mice. Lymphocyte proliferation assays using splenocytes from immunized mice showed significant proliferative responses and cytokines interleukin-2 (IL-2), IL-4, IL-10 and IFN-gamma presence in the culture supernatants. The anti-AMA-1 rabbit antibodies obtained with both the proteins were active in an in vitro parasite growth invasion/inhibition assay. These results suggest that recombinant AMA-1 domain I+II formulated with CFA/IFA adjuvant elicited cellular and humoral responses and is capable of inducing high titer invasion inhibitory antibodies supporting further development of this vaccine candidate.

Electrical impedance signal analysis in assessing the possibility of non-invasive diagnosis of knee osteoarthritis

Knee osteoarthritis (OA) is a degenerating disorder that leads to pain, disability and dependence. Although significant numbers of elderly people are affected by this irreversible damage, not many non-invasive methods have been found that can detect onset of OA. The traditional x-ray has the disadvantage of detecting a problem only after many changes have taken place. Others, such as MRI and ultrasound, are either expensive or unsuitable for mass screening and repeated use. In this paper, an attempt has been made to study the usefulness of electrical impedance plethysmography (EIP) in non-invasive diagnosis of knee OA. In two experiments on 10 OA knees and eight control knees in groups aged 45 - 65 years (OA group: 62.40 +/- 3.47 years, controls: 53.38 +/- 8.55 years), knee swing (active flexion and extension of leg in sitting position, KS) and normal walking (WN) electrical impedance changes (DeltaZ) around the knee were analysed. The results indicate that there is significant difference in amplitudes of signals. Difference in mean of variances of two groups was significant (p < 0.05) for KS and WN. The difference in the mean rms values was also significant (p < 0.05) for KS and WN. Impedance changes suggest that EIP signal around the knee have the potential for non-invasive diagnosis of knee OA.

Statistical optimization for tannase production from Aspergillus niger under submerged fermentation

Statistically based experimental design was employed for the optimization of fermentation conditions for maximum production of enzyme tannase from Aspergillus niger. Central composite rotatable design (CCRD) falling under response surface methodology (RSM) was used. Based on the results of 'one-at-a-time' approach in submerged fermentation, the most influencing factors for tannase production from A. niger were concentrations of tannic acid and sodium nitrate, agitation rate and incubation period. Hence, to achieve the maximum yield of tannase, interaction of these factors was studied at optimum production pH of 5.0 by RSM. The optimum values of parameters obtained through RSM were 5% tannic acid, 0.8% sodium nitrate, 5.0 pH, 5 × 10(7) spores/50mL inoculum density, 150 rpm agitation and incubation period of 48 h which resulted in production of 19.7 UmL(-1) of the enzyme. This activity was almost double as compared to the amount obtained by 'one-at-a-time' approach (9.8 UmL(-1)).

Differential effects of cyclic and static pressure on biochemical and morphological properties of chondrocytes from articular cartilage

BACKGROUND

Mechanical stresses are known to play important role on articular cartilage functions in vivo and also on cartilage explants and chondrocytes monolayer culture. This study examined the differential effect of cyclic and static pressures on chondrocytes cultured in alginate matrix, which is physiologically closer to the in vivo environment of cells in cartilage.

METHODS

Goat knee joint articular cartilage chondrocytes cultured in alginate beads were exposed to 1.2 and 2.4 MPa cyclic and static loadings via a custom-made cam/follower based machine. Biochemical contents (glycosaminoglycan, collagen, DNA) and protease activity of cells were analyzed separately in cellular matrix, further removed matrix and in culture medium. Morphology of chondrocytes was studied under transmission electron microscopy.

FINDINGS

Compared with controls (unloaded cells), cyclic loading increased the glycosaminoglycan content of cells at 1.2 and 2.4 MPa in cellular matrix and further removed matrix (P<0.001) whereas it decreased at similar static loads (P<0.001). In alginate matrix, chondrocytes released a metalloprotease, which required Mn(2+) for activity. Both cyclic load levels inhibited its specific activity in cellular matrix but increased it at static loading (P<0.001). The protease specific activity in further removed matrix increased at both cyclic and static loadings (P<0.001). Transmission electron microscopy data showed improved cells ultrastructure and cell-matrix interactions under cyclic load whereas these deteriorated under static loadings.

INTERPRETATION

The study suggests that cyclic load has a positive effect on chondrocytes metabolism and morphology whereas static load has a degenerative effect.

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.

A cost effective fermentative production of succinic acid from cane molasses and corn steep liquor by Escherichia coli

AIM

Development and optimization of an efficient and inexpensive medium for succinic acid production by Escherichia coli under anaerobic conditions.

METHODS AND RESULTS

Initially, 0.8 gl(-1) of succinic acid was produced in 60 h in 300-ml medium. On optimization, glucose and peptone were replaced by cane molasses and corn steep liquor. Three hundred ml of this medium was inoculated with 4% (v/v) of seed inoculum, incubated at 39 degrees C for 72 h, resulted in 7.1 gl(-1) of succinic acid in 36 h. Scale up in a 10-l fermentor under conditions of controlled pH and continuous CO2 supply in this medium resulted in 17 gl(-1) of succinic acid in 30 h.

CONCLUSIONS

A ninefold increase in succinic acid production was obtained in 500-ml anaerobic bottles with optimized medium having cane molasses and corn steep liquor as against initial medium containing glucose and peptone. However, a subsequent scale up in a 10-l fermentor resulted in a 2.5-fold increase in succinic acid production as against optimized medium used in 500-ml anaerobic bottles.

SIGNIFICANCE AND IMPACT OF THE STUDY

Succinic acid production was enhanced in medium consisting of inexpensive carbon and nitrogen sources in a shorter span of time.

Arteriovenous malformation and Color Doppler: posterior auricular artery

Arterio-venous malformations (AVM) are rare in head and neck region and are generally arise from intracranial vessels. We present a case of spontaneous AV malformation in the post auricular region with posterior auricular artery as the feeding vessel that was diagnosed by Color Doppler sonography.

Esthesioneuroblastoma: A case report and review of the literature

Esthesioneuroblastoma (ENB) is an extremely rare malignant neoplasm of the nasal cavity. We report the case of a middle aged man who presented with a 6-months history of progressive nasal obstruction, watering of the eye, headache and occasional epistaxis. A diagnosis of esthesioneuroblastoma was established by histopathology and confirmed by immunohistochemistry. On staging the mass was classified as a kadish stage C tumor. The mass was excised via a craniofacial resection through a bi-coronal approach and the tumor mass was peeled away completely from the frontal lobe dura. The patient underwent postoperative radiation, and he was free of recurrence at follow-up 3 months later.

Glomerular diseases in the elderly in India

Three hundred fifteen (315) elderly (> or = 60 years) patients with clinical renal diseases were evaluated for the evidence of glomerular diseases between November 1998 to June 2002. Glomerular diseases (GN) were observed in 20.6% (65/315) of the elderly patients. The age of the patients (male 56; female 9) ranged between 60-90 (mean 64.17 +/- 3.83) years. The clinical presentation of GN included: nephrotic syndrome 40 (61.5%), acute nephritic syndrome 19 (29.2%), rapidly progressive GN 4 (6.15%) and asymptomatic urinary abnormality 2 (3.0%). Overall, primary and secondary glomerular disease were seen in 47 (72.3%) and 18 (27.6%) elderly patients respectively. Idiopathic membranous nephropathy was the most common GN responsible for nephrotic syndrome in 11 (27.5%) of elderly patients. Diabetic Nephropathy related to type 2 diabetes mellitus was the second common cause 9 (22.5%) of nephrotic syndrome. Amyloidosis was noted in 6 (15%) patients. Nephrotic syndrome was related to leprosy in one patient. Amyloidosis occurred in association with multiple myeloma in 5 and carcinoma colon in 1 patient. Thus, primary and secondary GN were responsible for nephrotic syndrome in 60% and 40% of cases respectively. Endocapillary proliferative GN of post infectious etiology was the most prevalent (82.6%) form of acute GN in our elderly patients. Hypertension occurred in 78.2% of cases and edema in 69.5%. Pulmonary congestion (52.2%) and ARF (73.9%) were the dominant presenting feature of acute GN and 39% of patients required dialytic support. Glomerular crescents were seen in 4 (17.4%) patients with acute glomerulonephritis. Pauci-immune crescentic GN which is the commonest type of acute GN in the elderly in western countries was not observed in this study. Renal biopsy revealed mesangiocapillary GN (1) and mesangioproliferative GN (1) in two patients with asymptomatic urinary abnormalities. Thus, overall spectrum of glomerular disease in the Indian elderly population is similar to that of developed countries except in two ways: (1) post infectious endocapillary proliferative-GN was the commonest type of acute GN (2) rarity or absence of pauci-immune crescentic glomerulonephritis.

Sino-nasal haemangiopericytoma

Hemangiopericytomas are very rare soft tissue tumors of vascular origin featurding pericyts distributed around vascular spaces. They have unpredictable biological behavior and a high local recurrence rate. Silver reticulin stain is essential for their histologic diagnosis. Approximately one third occur in the head and neck. Metastases occurs in nearly one half of all cases. They are relatively radioresistant despite their great vascular component. Wide local excision of the lesion, whenever feasible and lifelong follow-up should be the treatment of choice.

Testing of newly developed glycophospholipid antigen for the detection of P. falciparum malaria by laser light immunoassay in endemic and non-endemic areas

A glycophospholipid (GPL) antigen isolated from Plasmodium falciparum culture supernatant has been tested for its antigenicity. Detection of malaria positive known blood samples and unknown field samples from endemic and non-endemic areas were compared. In this study laser light scattering immunoassay (LIA) was used for the detection of P. falciparum malaria. Test results of control (malaria negative samples from Surat) were compared with known positive samples and unknown malaria positive field samples. A positive correlation has been observed (97%) in falciparum positive samples from laboratory and unknown samples from endemic area (Haldwani) by LIA method using GPL antigen. From the results of the study it was found that GPL antigen has a better antigenic property and can detect almost all the cases of Pf malaria by LIA method.

Acute renal failure in Plasmodium vivax malaria

OBJECTIVES

To analyze incidence, clinical feature and outcome of acute renal failure due to Plasmodium vivax malaria.

MATERIAL & METHOD

This is retrospective analysis of smear positive Plasmodium vivax patients with acute renal failure between Jan 1995 to Dec 2000.

RESULT

Out of 577 cases of ARF, 93 [falciparum 74 (79.61%); vivax 19 (20.4%)] were related to complicated malaria. 3.2% (19/577) patients, 16 males and three females with age range 17-72, mean 43.3 +/- 13.4 years were due to vivax malaria. Thirteen had only vivax and six had mixed falciparum and vivax infection. The presenting features were fever (100%), jaundice (36.8%), hypotension--eight (42%), encephalopathy--11 (57.9%), sepsis--five (26.3%) and DIC--four (21%). The probable contributory factors for ARF were heavy parasitemia--11 (57.9%), hypotension--six (31.5%), hyperbilirubinemia--seven (36.8%), hemolysis--eight (42%) and DIC--four (21%). Oliguria was present in 47.3%, 13 (68.4%) patients required dialysis. Mortality was noted in 15.7% (3/19) patients.

CONCLUSIONS

P. vivax malaria can cause ARF, which occurs more commonly in P. falciparum malaria. Renal ischemia is the dominant pathogenic mechanism that results in acute tubular necrosis. The prognosis of ARF in P. vivax malaria is favorable.

Design and development of an immunosensor for the detection of malaria in field conditions

Eradication of malaria in Southeast Asian countries is still a distant goal, due to the absence of a simple, rapid and inexpensive diagnostic technique. Here, an immunosensor for the photometric detection of malaria, the malaria-detecting immunosensor (MDI), is developed to detect Plasmodium falciparum malarial antibodies in human blood. The method uses the principle of laser light-scattering by latex bead agglutinates in media monitored by a light-detecting device. Agglutination is induced by mixing antigen-coated latex beads with serum antibodies. Immunoreactions are measured in terms of the Tyndall effect in the transmitted beam detected by photodiodes. MDI sensitivity and specificity are compared with the results of enzyme-linked immunoabsorbent assay and laser light-scattering immunoassay techniques, which show that it is a good and sensitive monitoring device.

Acute renal failure due to intrinsic renal diseases: review of 1122 cases

In this study we have analyzed incidence, causes and clinical course of ARF due to primary intrarenal disease other than acute tubular necrosis. Thousand hundred and twenty two cases of ARF of diverse etiology were studied over a period of 16 years; July 1984 to Dec, 1999. Surgical ARF 231 (20.6%) were not included in the present study. Intrinsic renal diseases were responsible for ARF in 891 (79.4%) of cases. The most common intrinsic renal diseases 705 (79.4%) causing ARF were ischemic/toxic acute tubular necrosis, but not included in this study. Acute renal failure was related to acute glomerulonephritis (9.3%), acute interstitial nephritis (7%), and renal cortical necrosis in (4.6%) of cases. Therefore intrinsic renal diseases other than ATN were the causative factor for acute renal failure in 186 (20.8%) patients in our study. Crescentic (51.8%) and endocapillary proliferative glomerulonephritis (34.9%), were the main glomerular diseases responsible for ARF and 75.9% of GN was related to infectious etiology. Fifty three percent of acute interstitial nephritis was drug induced and in 25 (40%) patients it was related to an infectious etiology. Renal cortical necrosis due to HUS was observed in 16 (39%) children and majority (76.47%) of the cases had a diarrhoeal prodrome. Obstetrical complications were the main causes (61%) of cortical necrosis in adults with acute renal failure. Thus, intrinsic renal diseases other than ATN were responsible for ARF in 186 (20.8%) cases. Post-infectious glomerulonephritis, acute interstitial nephritis and renal cortical necrosis (complicating HUS in children and obstetrical complications in adult) are the main causes of acute renal failure in our study. Both acute GN and interstitial nephritis had excellent prognosis, however renal cortical necrosis was associated with a very high mortality.

Purification strategies for microbial lipases

Microbial lipases today occupy a place of prominence among biocatalysts owing to their ability to catalyze a wide variety of reactions in aqueous and non-aqueous media. The chemo-, regio- and enantio-specific behaviour of these enzymes has caused tremendous interest among scientists and industrialists. Lipases from a large number of bacterial, fungal and a few plant and animal sources have been purified to homogeneity. This has enabled their successful sequence determination and their three-dimensional structure leading to a better understanding of their unique structure-function relationships during various hydrolytic and synthetic reactions. This article presents a critical review of different strategies which have been employed for the purification of bacterial, yeast and fungal lipases. Since protein purification is normally done in a series of sequential steps involving a combination of different techniques, the effect of sequence of steps and the number of times each step is used is analyzed. This will prove to be of immense help while planning lipase purification. Novel purification technologies now available in this field are also reviewed.

Spectrum of renal diseases in the elderly: single center experience from a developing country

From November 1998 to March 2000, two hundred patients over the age of 60 years (Elderly) with clinical renal disease were studied. 144 patients were between ages of 60-69 years, 46 between 70-79 years and 10 were above 80 years. The elderly patients (Male 165; Female 35) with renal disease constituted 11% (200/1816) of the total nephrology consultation during the study period. The clinical presentation included chronic renal failure (42.5%); acute renal failure (28%); nephrotic syndrome (14.5%); acute glomerulonephritis (7.5%); renal vascular disease (5%) and renal cystic disease (2.5%). Diabetic nephropathy, obstructive uropathy and hypertensive nephrosclerosis were the major causes of CRF, accounting for 80% of total CRF in the elderly. Chronic glomerulonephritis and chronic pyelonephritis (CPN) were less common and etiology of CRF was uncertain in 5.9% of cases. However, diabetic nephropathy was the commonest (49.4%) cause of chronic renal failure. We did not see a single case of ischemic nephropathy causing CRF in the present study. Prerenal ARF, obstructive uropathy and sepsis were contributing factors for ARF in 82% of the cases. Volume depletion due to gastrointestinal fluid loss and urinary tract obstruction on account of enlarged prostate were the leading causes of ARF in 20 (35.7%) and 8 (14.3%) cases respectively. Sepsis with or without multiorgan failure was the major (46.7%) cause of mortality in patients with ARF and overall mortality was 26.8%. The commonest (31%) cause of nephrotic syndrome was the idiopathic membranous nephropathy. Diabetic nephropathy related to type-2 diabetes mellitus was the second most common (24.1%) cause of nephrotic syndrome. Diffuse endocapillary proliferative GN of post infectious etiology was the commonest (73.3%) type of acute GN in our elderly patients. Renal cystic diseases were noted in 5 (ADPKD 3; Simple cyst-2) patients. Thus, overall spectrum of renal disease in our elderly patients is similar to that of developed nations except in two ways: (i) Endocapillary proliferative GN of post infectious origin was the commonest type of acute GN and (ii) Rarity or absence of ischemic nephropathy and atherosclerotic renal artery occlusive disease.

Study of malaria in a village of lower Myanmar

Malaria endemicity in lower Myanmar has been studied to identify the causes for the prevalence of malaria in Yeasitkan village of lower Myanmar. Vector mosquitoes were collected by mosquito net in cattlesheds and in human dwellings (indoor and outdoor) by biting and catching procedure for the identification of species, insecticide susceptibility test and sporozoites detection. Larvae of mosquitoes were also collected in and around the village for vector identification and for breeding sources. Malaria infection in humans was examined by blood examination and blood antibody detection by ELISA method. Results showed that malaria infection was 43.2% in children under 10 years of age and An. dirus and An. minimus were found as main vectors. Total parasite positive rate was found to be 41.28% and in this 78.87% were P. falciparum infections and remaining 18.31% were of P. vivax. Spleen positive rate has been found very high in children between 2 and 9 years (52.94%). Study indicates that villages near to dam areas are more prone to malaria infection.

Kinetics of changes in lymphocyte sub-populations in mouse lungs after intrapulmonary infection with M. bovis (Bacillus Calmette-Guerin) and identity of cells responsible for IFNgamma responses

Gamma interferon (IFNgamma) plays a key role in host defense against pulmonary mycobacterial infections. A variety of lymphocyte subsets may participate in producing pulmonary IFNgamma responses, but their relative contributions after mycobacterial infection have not been clearly elucidated. To address this question, C57Bl/6 female mice were infected by intrapulmonary instillation of 2.5 x 104 BCG (Mycobacterium bovis Bacillus Calmette-Guerin). Lymphocyte populations in lung interstitium were examined at different time points after the infection. BCG load in lungs peaked between 4 and 6 weeks post-infection and declined to very low levels by the 12th week of infection. Recovery of lung interstitial lymphocytes doubled by 4-6 weeks after infection and declined thereafter. Flow cytometric analysis of the lung-derived lymphocytes revealed that about 5% of the these cells made IFNgamma in control mice, and this baseline IFNgamma production involved T (CD3+NK1.1-), NK (CD3-NK1.1+) and NKT (CD3+NK1.1+) cells. As the BCG lung infection peaked, the total number of CD3+ T cells in the lungs increased threefold at 5-6 weeks post-infection. There was a marked increase (sixfold) in the number of T cells secreting IFNgamma 5-6 weeks post-infection. Some increase was also noted in the NKT cells making IFNgamma, but the numbers of NK cells making IFNgamma in BCG-infected lungs remained unaltered. Our results suggest that whereas NK and NKT cells contribute to baseline IFNgamma secretion in control lungs, expansion in the IFNgamma-producing T-cell population was essentially responsible for the augmented response seen in lungs of BCG-infected mice.

Kinetic constants determination for an alkaline protease from Bacillus mojavensis using response surface methodology

The kinetic constants for an alkaline protease from Bacillus mojavensis were determined using a central composite circumscribed design (CCCD) where concentration of substrate (casein) and the assay temperature were varied around their center point. The K(m),V(max), K(cat), activation energy (E(a)) and temperature coefficient (q(10)) were determined and the values of these kinetic constants obtained were found comparable to that obtained with conventional methods. The Michaelis-Menten constant (K(m)) for casein decreased with corresponding increase in V(max), as reaction temperature was raised from 45-60 degrees C. The protease exhibited K(m) of 0.0357 mg/ml, 0.0270 mg/ml, 0.0259 mg/ml, and 0.0250 mg/ml at 45, 50, 55, and 60 degrees C, respectively, whereas V(max) values at these temperatures were 74.07, 99.01, 116.28, and 120.48 microg/ml/min, respectively, as determined by response surface methodology. The Arrhenius plot suggested that the enzyme undergoes thermal activation above 45 degrees C until 60-65 degrees C followed by thermal inactivation. Likewise, the energy of activation (E(a)) was more between 45-55 degrees C (9747 cal/mol) compared to E(a) between 50-60 degrees C (4162 cal/mol).

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.

Microwave-assisted rapid characterization of lipase selectivities

A rapid screening procedure for characterization of lipase selectivities using microwaves was developed. The rate of reaction of various commercial lipases (porcine pancreas, Mucor miehei, Candida rugosa, Pseudomonas cepacia) as well as lipases from laboratory isolates-Bacillus stearothermophilus and Burkholderia cepacia RGP-10 for triolein hydrolysis was 7- to 12-fold higher in a microwave oven as compared to that by pH stat. The esterification of sucrose/methanol and ascorbic acid with different fatty acids was also achieved within 30 s in a microwave using porcine pancreas, B. stearothermophilus SB-1 and B. cepacia RGP-10 lipases. The relative rates and selectivity of the lipases both for hydrolytic and synthesis reactions remains unaltered. However, the rate of reaction was dynamically enhanced when exposed to microwaves. Microwave-assisted enzyme catalysis can become an attractive procedure for rapid characterization of large number of enzyme samples and substrates, which otherwise is a cumbersome and time-consuming exercise.

Detection of Mycobacterium tuberculosis antigens in urinary proteins of tuberculosis patients

A sensitive sandwich enzyme-linked immunosorbent assay (ELISA) that can detect up to 0.5 ng of culture filtrate proteins (CFPs) of Mycobacterium tuberculosis strain H37Ra is described. This detection system features several special characteristics: (i) the use of CFPs from the H37Ra strain of Mycobacterium tuberculosis to generate capture and detection antibodies in rabbits and mice, respectively; (ii) affinity purification of CFP-reactive antibodies and selection of the antibody preparations for best performance in the sandwich ELISA system; and (iii) the use of urine-derived protein preparations for antigen detection. The sandwich ELISA could detect up to 0.5 ng of CFPs of the H37Ra strain of Mycobacterium tuberculosis. The assay did not detect antigens of Escherichia coli, Candida albicans or Saccharomyces cerivisiae but efficiently detected CFP preparations from nine different clinical isolates of Mycobacterium tuberculosis. Significant variations, however, were noted in the relative efficacy of the assay to detect CFPs from different clinical isolates of Mycobacterium tuberculosis. The procedure was utilized for detecting tubercular antigens in urine samples from 29 patients with confirmed (sputum-positive) tuberculosis and from 25 healthy controls. Significant levels of antigen could be detected in 22 of the 29 samples tested.

Microwave induced synthesis and antibacterial activity of cephalosporin derivatives using solid support

Reaction of 7-amino-3-[5'-methyl-1',3',4'-thiadiazol-2'-ylthiomethyl]cephalo-sporanic acid with heterocyclic amines using basic alumina under microwave irradiation (MWI) afforded new cephalosporin analogs in shorter reaction time with improved yield as compared to conventional heating. All the synthesised compounds were tested for their in vitro antibacterial activity, using cefotaxime and cephalothin as reference drugs. All compounds showed significant in vitro antibacterial activity against E. herbicola, P. vulgaries, and Z. mobilis.

Reduced uptake as a mechanism of zinc tolerance in Oscillatoria anguistissima

Oscillatoria anguistissima could tolerate 50 ppm ZnSO4 x 7H2O, and a zinc-tolerant strain with maximum tolerance concentration (MTC) of 100 ppm ZnSO4 x 7H2O was obtained by stepwise transfer to higher concentrations. The adaptation was irreversible even after three generations in metal-free medium. In the presence of metal, the tolerant strain grew with a shorter lag period of 4 days as against 6 days in the case of the wild strain. The tolerant strain had higher MTC than that of the wild strain for other metals also, viz., Ni2+, Co2+, Cu2+ and Cd2+. The zinc resistance in the tolerant strain was a result of reduced uptake, since around 42% of the total metal was present on the surface as against only 30% in the wild strain. The calcium-stimulated uptake, as observed in the wild strain, was absent in the tolerant strain. Ultrastructural comparisons revealed no structural change in the tolerant strain on exposure to zinc, whereas in the wild strain a thick extracellular matrix was observed.

Acute renal failure complicating rifampicin therapy

BACKGROUND

Since 1971, 55 case-reports of rifampicin-induced acute renal failure (ARF) have been published. Covic et al described 60 consecutive cases of rifampicin-induced ARF during a period of eight years (1987-1995) from Iasi Dialysis Centre, Romania. The systenic data on this condition are not available, in view of the anecdotal nature of the observation from our country.

OBJECTIVE

The aims of study were to analyze clinical features, course and outcome of ARF complicating rifampicin therapy at our centre.

METHODS

We retrospectively studied prevalence, clinical presentations and renal histology and outcome of 11 cases (eight males, three females, aged 42-72 years) who were referred to Nephrology Unit of University Hospital, Varanasi for acute renal failure following retreatment with rifampicin between period of 1994-1999.

RESULTS

The gastrointestinal symptoms (abdominal pain, nausea and vomiting) and 'flu like' (fever, weakness and body ache) syndrome were the most frequent presenting features. The clinical signs of intravascular hemolysis were observed in four cases. The commonest laboratory findings included: Anaemia (7), leukocytosis (5), thrombocytopenia (3) and toxic hepatitis in (2) patients. Toxic hepatitis, hemolysis and ARF was seen in one patient in combination. The typical clinical features of allergic interstitial nephritis and acute tubular necrosis were seen in six and two patients respectively. Renal biopsy in three cases revealed; crescentic GN (1) and ATN in (2) patients. Acute renal failure complicating rifampicin accounted for 1.8% (11/607) of all ARF cases hospitalized in our centre during the study period. Renal function returned to normal in nine cases and one patient died on account of hepatic failure (toxic hepatitis). The patients with crescentic GN remained anuric and became dialysis dependent. Thus, clinical course of rifampicin induced ARF was favourable; with only one mortality, compared to a 18% mortality rate among all ARF patients.

CONCLUSION

Acute renal failure complicating rifampicin therapy is not an uncommon condition, and typically occurs after reintroduction of rifampicin. The renal prognosis is usually favourable. Intermittent or interrupted therapy appears to be a significant risk factor for the development of acute renal failure.

Abrogation of tumor induced Ly49 expression on mouse spleen cells by mitomycin C

Mouse spleen cells were activated with IL2 for 4 days in the presence or absence of paraformaldehyde fixed YAC (PFY) tumor cells (spleen cell: PFY ratio 100:1). Fresh spleen cells had poor expression of Ly49A but the expression was significantly upregulated by IL2 activation. Addition of PFYs resulted in a further boosting of Ly49A expression. Besides Ly49A, the Ly49C receptors were also upregulated by PFYs. Upregulated Ly49 expression was not restricted to NK cells (NK1.1 positive cells) but was also seen on T cells (TCRbeta positive cells). Time kinetics studies indicated that maximum upregulation of Ly49 in response to PFY cells occurred on day 3 and 4 and the expression declined thereafter. Ly49 expression in response to PFYs was completely blocked if spleen cells were pre-treated with Mitomycin C, an inhibitor of DNA synthesis. These results show that the addition of a small number of paraformaldehyde fixed YAC cells to spleen cell cultures undergoing IL2 activation, resulted in a significant upregulation of Ly49 receptors and this process was dependent upon cell proliferative activity.

Biocatalytic potential of Fusarium globulosum lipase in selective acetylation/deacetylation reactions and in ester synthesis

AIMS

The present study was carried out to assess the potential of Fusarium globulosum lipase (FGL) for chemoselective and regioselective biotransformations for the synthesis of industrially important organic compounds.

METHODS AND RESULTS

Different acetylation/deacetylation reactions and ester synthesis reactions were carried out in organic media. Fusarium globulosum lipase showed exclusive selectivity for the acetylation of the alcoholic hydroxyl group over the phenolic hydroxyl group of the hydroxymethylated phenols and aryl alkyl ketones. This also led to the enantiomeric resolution of the aryl alkyl ketone. In contrast, the lipase showed reversed selectivity in deacetylation where it preferred the phenolic acetoxy group over the alcoholic acetoxy moiety of the peracetates of hydroxymethylated compounds. The enzyme also exhibited strict regioselection for deacetylation at the para position of the peracetate of an aryl alkyl ketone. In addition, the lipase also synthesized a variety of industrially important fatty acid esters of sugars, sugar alcohols, alcohols and ascorbic acid with high preference for middle-chain fatty acids.

CONCLUSION

Fusarium globulosum lipase shows versatile catalytic potential in terms of chemo-, enantio- and regioselectivity and fatty acid specificity in carrying out a variety of industrially important biotransformations.

SIGNIFICANCE AND IMPACT OF THE STUDY

The biocatalytic potential of FGL can thus be utilized for the synthesis and modification of different types of polyphenolic compounds and esters. These compounds find widespread uses as surfactants, bioactive analogues, antioxidants and flavour components in the food, detergent, pharmaceutical and cosmetic industries.

Microwave assisted solid support synthesis of novel 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazepines as potent antimicrobial agents

An environmentally benign and economic synthesis of 1,2,4-triazolo[3,4-b]-1,3,4-thiadiazepines is described from readily accessible substituted 2-mercapto-1-amino triazoles and substituted chalcones on basic alumina that are accelerated by exposure to microwaves. The reaction time has been brought down from hours to seconds with improved yield as compared to conventional heating. The method reported herein is devoid of the hazards of solution phase reactions. All the synthesised compounds were tested for their in vitro antibacterial and antifungal activity. Some compounds showed significant antimicrobial properties. The best activity was observed with compounds 3a, 3c, 4a and 4d.

Efficacy of culture filtrate protein preparations from Indian isolates of M. tuberculosis to activate T cells derived from healthy donors

SETTING

While culture filtrate proteins (CFPs) of Mycobacterium tuberculosis appear to be good vaccine candidates for tuberculosis, only CFPs derived from certain popular laboratory strains of M. tuberculosis have been studied for this purpose.

OBJECTIVE

To compare the relative efficacies of CFP preparations from two laboratory strains and four contemporary clinical isolates of M. tuberculosis to induce T-cell activation.

DESIGN

CFPs were isolated from six strains of M. tuberculosis and were used to induce 1) T-cell proliferation, 2) IFN-gamma secretion, and 3) IL-12 secretion from peripheral blood derived mononuclear cell (PBMC) preparations from 33 healthy donors.

RESULTS

Significant amounts of IL-12 were spontaneously secreted by PBMC preparations; CFP preparations from two clinical isolates (JNU-7 and JNU-51) significantly boosted this response. All six CFP preparations induced IFN-gamma secretion by PBMCs, but those from two contemporary strains of M. tuberculosis (JNU-7 and JNU-22) were most effective in this regard. The effect of CFPs from JNU-7 and JNU-22 was significantly better than those from the laboratory strains (H37Ra and Erdman). Similar results were obtained with the T-cell proliferation parameter.

CONCLUSION

These results suggest that CFPs derived from selected clinical isolates of M. tuberculosis may outperform those of standard laboratory strains, and may therefore be a better source of potential candidates for a tuberculosis vaccine.