Spectrum of malignancies in human immunodeficiency virus - positive patients at a Tertiary Care Centre in South India.

CONTEXT: India has a very large number of patients living with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome. Opportunistic infections in these patients are commonly encountered. However, malignancies in such patients also do occur. AIM: The aim was to study the spectrum of malignancies in HIV-positive patients at a tertiary health care center. SETTINGS AND DESIGN: Retrospective study. MATERIALS AND METHODS: The cases were retrieved from pathology record files at our Institute from January 2003 to December 2008. The follow-up was obtained from Medical oncology records. The morphology of each case was reviewed along with immunohistochemistry wherever done. RESULTS: There were 61 such cases (51 males, 10 females). The age range was 7-78 years with a median of 35 years. The clinical presentation varied according to the malignancy. The largest group was non-Hodgkin lymphoma (18 nodal, 23 extra-nodal). The others included carcinoma breast (4), chronic myeloid leukemia (3), Burkitt Leukemia (2), squamous cell carcinoma anal region (2), multiple myeloma (2) and one each of miscellaneous malignancies (7). CONCLUSION: Malignancies in HIV positive individual occurred in younger individuals. Non-Hodgkin lymphomas, especially extra-nodal lymphomas, were the most common malignancy. There were no cases of proven Kaposi's sarcoma or invasive cervical carcinomas. There were two cases of multiple myeloma which are infrequently reported.

Insights into the mechanism of drug resistance: X-ray structure analysis of G48V/C95F tethered HIV-1 protease dimer/saquinavir complex.

The mutation G48V in HIV-1 protease is a major resistance mutation against the drug saquinavir. Recently, G48V mutation is found to co-exist with the mutation C95F in AIDS patients treated with saquinavir. We report here the three-dimensional crystal structure of G48V/C95F tethered HIV-1 protease/saquinavir complex. The structure indicates following as the possible causes of drug resistance: (1) loss of direct van der Waals interactions between saquinavir and enzyme residues PHE-53 and PRO-1081, (2) loss of water-mediated hydrogen bonds between the carbonyl oxygen atoms in saquinavir and amide nitrogen atoms of flap residues 50 and 1050, (3) changes in inter-monomer interactions, which could affect the energetics of domain movements associated with inhibitor-binding, and (4) significant reduction in the stability of the mutant dimer. The present structure also provides a rationale for the clinical observation that the resistance mutations C95F/G48V/V82A occur as a cluster in AIDS patients.

Alpha and beta-galactosidase activities and oligosaccharide content in peanuts.

Thirty-three peanut cultivars were examined for their alpha-1,6 and beta-1,4 galactosidase activities and oligosaccharide contents along with proximate compositions. The average moisture, protein, fat, ash, and carbohydrate contents were: 4.9%, 26.6%, 43.1%, 2.3% and 23.1%, respectively. The corresponding coefficients of variation were: 5.2%, 10.1%, 7.2%, 7.8% and 15.7%, respectively. Raffinose and stachyose contents (%) ranged from 0.05 to 0.12 and 0.31 to 0.61, respectively. The specific activity (micromol product/min/mg protein) of crude preparation of alpha-galactosidase for the 33 cultivars ranged from 1.096 to 2.784 for the non-germinated seeds and from not being detected in some samples up to 2.432 for the germinated seeds; the mean values for non-germinated and germinated seeds were: 1.781 and 1.410, respectively. The specific activity of beta-galactosidase ranged from 0.101 to 1.727 in the non-germinated seeds and from not being detected in some samples up to 0.898 in the germinated seeds. Germination decreased the activity of both galactosidases significantly (p < or = 0.05).

Dietary inulin suppresses azoxymethane-induced preneoplastic aberrant crypt foci in mature Fisher 344 rats.

Preneoplastic aberrant crypt foci (ACF) are generally accepted as reliable markers for colon carcinogenesis in animal models. Rat model ACF studies, however, use younger rats, and there are no published reports on the suitability of adult rats for ACF studies. In this study, inulin, a known suppressor of azoxymethane (AOM)-induced ACF, was tested for its ability to suppress ACF formation in mature rats. After a 2-wk acclimation period, 12-mo-old Fisher 344 retired male breeders received two subcutaneous injections of AOM dissolved in saline at weekly intervals. In experiment 1, six groups received 0, 4, 8, 10, 12 and 16 mg AOM/kg body at each injection and were fed AIN-93M diet. In experiment 2, four groups of rats were fed 10 mg AOM/kg body at each injection based on the results of experiment 1, and were fed 0, 2.5, 5 and 10 g long-chain inulin diets/100 g. All the rats were killed after 11-wk feeding periods. In experiment 1, there was a significant (P < 0.05) AOM dose response on ACF formation. Rats fed >10 mg of AOM had greater (P < 0.05) mortality. In experiment 2, there was a significant increase in cecal weight and a decrease in cecal pH from 7.17 in the control group to 6.87, 6.61 and 5.76 in the groups fed inulin at 2.5, 5.0 and 10 g/100 g, respectively. Long-chain inulin dose-dependently reduced ACF incidence in the colon (P < 0.01). Compared with rats fed the control diet, the percentage reductions of ACF in rats fed 2.5, 5.0 and 10 g inulin diets/100 g were 25, 51, and 65, respectively. The results of this study indicate that mature rats can be used as models in ACF studies, and dietary long-chain inulin dose-dependently suppresses AOM-induced ACF formation in Fisher 344 mature male rats.

Dietary inulin suppresses azoxymethane-induced aberrant crypt foci and colon tumors at the promotion stage in young Fisher 344 rats.

This study was designed to determine the effect of 10% dietary long-chain inulin on the azoxymethane (AOM)-induced colonic preneoplastic aberrant crypt foci (ACF) and small intestinal and colon tumors at the initiation (I), promotion (P) and I + P stages (20 rats per treatment) in Fisher 344 male weanling rats. After an acclimatization period of 1 wk, groups of Fisher 344 male weanling rats were assigned to consume AIN 93G diet (control) or AIN 93G diet containing 10% inulin. All the rats received 16 mg/kg body AOM dissolved in saline subcutaneously at 7 wk of age followed by a second injection at 8 wk of age. An additional group of five rats received only saline and consumed the control diet. The rats received the assigned diets until asphyxiation by CO(2) at 16 wk of age for the ACF experiment and 45 wk for the end-point tumor experiment. Feed intake, weight gain, diarrheal index, cecal weight, cecal pH, ACF and tumors in the colon were determined. Rats fed inulin had diarrhea after 2 wk of feeding and recovered by approximately 4 wk. Cecal weight was greater in rats fed inulin and cecal pH was lower. The inulin group had more than 66% fewer aberrant crypts and 60% fewer ACF compared with the control group. Tumor incidences in the small intestine and colon of rats in the control, I, P and I + P groups were: 78, 31, 0 and 11% and 90, 73, 69 and 50%, respectively. The corresponding values for the distal portion of the colon were 87, 63, 45 and 33%, respectively. Colon tumors per tumor-bearing rat were 4.2, 3.09, 1.36 and 1.2 for the control, I, P and I + P groups, respectively. All groups differed, P < 0.05. The results of this study indicate that dietary long-chain inulin suppresses AOM-induced ACF formation, an early preneoplastic marker of colon tumorigenesis in rats, and colon tumors, particularly at the promotion stage.

Various levels of cross-resistance to Bacillus sphaericus strains in Culex pipiens (Diptera: Culicidae) colonies resistant to B. sphaericus strain 2362.

We studied the cross-resistance to three highly toxic Bacillus sphaericus strains, IAB-59 (serotype H6), IAB-881 (serotype H3), and IAB-872 (serotype H48), of four colonies of the Culex pipiens complex resistant to B. sphaericus 2362 and 1593, both of which are serotype H5a5b strains. Two field-selected highly resistant colonies originating from India (KOCHI, 17,000-fold resistance) and France (SPHAE, 23,000-fold resistance) and a highly resistant laboratory-selected colony from California (GeoR, 36,000-fold resistance) showed strong cross-resistance to strains IAB-881 and IAB-872 but significantly weaker cross-resistance to IAB-59 (3- to 43-fold resistance). In contrast, a laboratory-selected California colony with low-level resistance (JRMM-R, 5-fold resistance) displayed similar levels of resistance (5- to 10-fold) to all of the B. sphaericus strains tested. Thus, among the mosquitocidal strains of B. sphaericus we identified a strain, IAB-59, which was toxic to several Culex colonies that were highly resistant to commercial strains 2362 and 1593. Our analysis also indicated that strain IAB-59 may possess other larvicidal factors. These results could have important implications for the development of resistance management strategies for area-wide mosquito control programs based on the use of B. sphaericus preparations.

Reduction of fecal shedding of enterohemorrhagic Escherichia coli O157:H7 in lambs by feeding microbial feed supplement.

Enterohemorrhagic Escherichia coli O157:H7, an emerging food-borne pathogen, has been implicated in several outbreaks in the US. Ruminants, including cattle, sheep and deer are reservoirs of E. coli O157:H7 and fecal shedding of the pathogen forms the vehicle of entry into the human food chain. We studied the efficacy of Lactobacillus acidophilus, Streptococcus faecium, a mixture of L. acidophilus and S. faecium and a mixture of L. acidophilus, S. faecium, Lactobacillus casei, Lactobacillus fermentum and Lactobacillus plantarum in reducing fecal shedding of E. coli O157:H7 by sheep experimentally infected with the pathogen prior to administration with the microbials. Following oral inoculation with 10(10)CFU of E. coli O157:H7, 30 Suffolk ram lambs were blocked by body weight (six blocks of five lambs each) and lambs within the block randomly assigned to five groups. The lamb groups were fed daily for 7 weeks a basal diet without microbial supplement (control) or the basal diet with L. acidophilus or with S. faecium or with a mixture of L. acidophilus and S. faecium or with a mixture of L. acidophilus, S. faecium, L. casei, L. fermentum and L. plantarum. The microbial supplements contained stabilized live naturally occurring bacteria and were mixed with the diet at the rate of 6.0x10(6)CFU per kilogram of diet. Fecal samples were collected weekly and analyzed for E. coli O157:H7 using modified tryptic soy broth with novobiocin as a pre-enrichement broth and cefixim-tellurite sorbitol MacConkey agar (CT-SMAC) as a selective media. E. coli O157:H7 was confirmed by its reaction with O157 and H7 antisera. E. coli O157:H7 was shed continuously and in varying numbers in the feces throughout the 7-week experimental period by all five groups. However, lambs administered a mixture of L. acidophilus, S. faecium, L. casei, L. fermentum and L. plantarum shed significantly lower (P=0.0211) average number of E. coli O157:H7 (2.3log(10)CFU per gram of feces per week) than the other lamb groups over the entire experimental period. S. faecium supplemented lambs were comparable (P=0.0884) to lambs fed a mixture of L. acidophulus and S. faecium in fecal shedding of the pathogen (3.5 versus 4.4log(10)CFU per gram of feces) but significantly lower (P=0.0001) than the control lambs (5.6log(10)CFU per gram of feces) and those supplemented with L. acidophilus (5.5log(10)CFU per gram of feces). Average daily gain (ADG) and gain to feed ratio (G:F) were significantly improved (P=0.0145) by the mixed culture microbials (163.0g and 0.33 for the control, 186.4g and 0.37 for L. acidophulus, 168.2g and 0.36 for S. faecium, 213.6g and 0.46 for L. acidophulus and S. faecium, and 219.1g and 0.44, respectively for L. acidophilus, S. faecium, L. casei, L. fermentum and L. plantarum supplemented lambs. The study indicates that supplementing lambs infected with E. coli O157:H7 with S. faecium or a mixture of S. faecium, L. acidophilus, L. casei, L. fermentum and L. plantarum in the diet can reduce total number of E. coli O157:H7 shed in the feces and improve animal meat production performance as well.

Cross-resistance to Bacillus sphaericus strains in Culex quinquefasciatus resistant to B. sphaericus 1593M.

Bacillus sphaericus 1593M resistant larvae of Culex quinquefasciatus were reared in the laboratory since 1995. Resistance in the larvae was monitored by subjecting selection pressure using B. sphaericus 1593M at every generation. Bioassays were conducted with different strains of B. sphaericus (Bs 2297, Bs 2362 and Bs IAB 59) and confirmed cross-resistance in the present study. The level ranged between 27.3 to 18.2 fold in comparison with susceptible larvae. But Bacillus thuringiensis var israelensis strains (Bti PG14 and Bti 426) did not show any cross-resistance in the larvae and it emphasized a need to study the mode of action of B. sphaericus toxin that induces cross-resistance in the larval strain.

Interactive suppression of aberrant crypt foci induced by azoxymethane in rat colon by phytic acid and green tea.

Several epidemiological studies point to a strong correlation between nutrient composition of the diet and cancer of the colon. Phytic acid, present in grains, has been credited with reducing the risk of cancer of the colon. A number of reports are available indicating the benefits of green tea consumption in reducing the risk of stomach, lung and skin cancer, but little data are available on the effect of green tea in reducing the risk of colon cancer. Also, there are no studies on the combined effect of these compounds on colon tumorigenesis. Thus the primary objective of this investigation was to elucidate the combined effects of green tea and phytic acid on colonic preneoplastic lesions and the Phase II enzyme glutathione S-transferase. Fisher 344 male weanling rats were divided into nine groups of 15 rats each and fed the experimental diet for 13 weeks. Rats received two s.c. injections of azoxymethane in saline at 16 mg/kg body wt at 7 and 8 weeks of age. Rats received three levels (0, 1 and 2%) of phytic acid with three levels (0, 1 and 2%) of green tea within each phytic acid level in a 3 x 3 factorial experiment. Results indicate that while green tea had a marginal effect (P < 0.14), phytic acid significantly reduced the incidence of aberrant crypt foci (P < 0.008). The interaction between green tea and phytic acid was significant (P < 0.029 for distal and < 0.0168 for entire colon) and positive, pointing to a synergistic effect of green tea and phytic acid.

Bifidobacterium longum and lactulose suppress azoxymethane-induced colonic aberrant crypt foci in rats.

Bifidobacterium longum has been shown to afford protection against colon tumorigenesis. Lactulose, a keto analog of lactose, serves as a substrate for preferential growth of Bifidobacterium. It is not known whether feeding lactulose along with B. longum will have any advantage over feeding of B. longum alone. To test this combination effect, 61 male Fisher 344 weanling rats were divided into four groups of 15 rats each (16 in the control group) and assigned to one of the following four diets for 13 weeks: (i) AIN76A (control, C); (ii) C + 0.5% B. longum (C+Bl, containing 1 x 10(8) viable cells/g feed); (iii) C + 2.5% lactulose (C+L); (iv) C + 0.5% B. longum + 2.5% lactulose (C+Bl+L). All animals received a s.c. injection of azoxymethane at 16 mg/kg body wt at 7 and 8 weeks of age. Colons of 10 rats from each dietary group were analyzed for aberrant crypt foci (ACF), which are preneoplastic markers. Colonic mucosa and livers from five rats were analyzed for glutathione S-transferase (GST, a Phase II enzyme marker). Results indicate that feeding of lactulose and B. longum singly and in combination reduces the number of ACF (P = 0.0001) and the total number of aberrant crypts significantly (P = 0.0005). The total number of ACF in diets C, C+Bl, C+L and C+Bl+L were 187 +/- 9, 143 +/- 9, 145 +/- 11 and 97 +/- 11 respectively. There was no significant difference in weight gain among treatments. Colonic mucosal GST levels were significantly (P = 0.05) higher in the Bl and L groups compared with group C. Initially there was a mild diarrhea in lactulose-fed rats. There was a positive correlation between higher cecal pH and number of ACF. Results of the study indicate that Bifidobacterium and lactulose exert an additive antitumorigenic effect in rat colon.

Analysis of the amino acid sequences of plant Bowman-Birk inhibitors.

Plant seeds contain a large number of protease inhibitors of animal, fungal, and bacterial origin. One of the well-studied families of these inhibitors is the Bowman-Birk family(BBI). The BBIs from dicotyledonous seeds are 8K, double-headed proteins. In contrast, the 8K inhibitors from monocotyledonous seeds are single headed. Monocots also have a 16K, double-headed inhibitor. We have determined the primary structure of a Bowman-Birk inhibitor from a dicot, horsegram, by sequential edman analysis of the intact protein and peptides derived from enzymatic and chemical cleavage. The 76-residue-long inhibitor is very similar to that of Macrotyloma axillare. An analysis of this inhibitor along with 26 other Bowman-Birk inhibitor domains (MW 8K) available in the SWISSPROT databank revealed that the proteins from monocots and dicots belong to related but distinct families. Inhibitors from monocots show larger variation in sequence. Sequence comparison shows that a crucial disulphide which connects the amino and carboxy termini of the active site loop is lost in monocots. The loss of a reactive site in monocots seems to be correlated to this. However, it appears that this disulphide is not absolutely essential for retention of inhibitory function. Our analysis suggests that gene duplication leading to a 16K inhibitor in monocots has occurred, probably after the divergence of monocots and dicots, and also after the loss of second reactive site in monocots.

Role of disulfide linkages in structure and activity of proteinase inhibitor from horsegram (Dolichos biflorus).

Proteinase inhibitor isolated from horsegram (Dolichos biflorus or Macrotyloma uniflorum) inhibited specifically the enzymes trypsin and chymotrypsin. The inhibitor contained seven disulfide linkages and was free from thiol groups. The inhibitor is resistant to denaturation by urea, guanidine hydrochloride or sodium dodecyl sulfate. Reduction of the inhibitor with dithiothreitol abolished both trypsin and chymotrypsin inhibitory activities. The kinetic plots of the reduction as followed by activity and loss in structure as reflected in the 257 nm CD band could be superposed; loss in the activity paralleled the loss in structure. The kinetics of the reduction process was complex; reduction of the inhibitor was slow and depended on the concentration of DTT. Reduction of the disulfide linkages with DTT affected the tertiary structure significantly and secondary structure was not affected considerably. Fluorescence quenching by acrylamide and potassium iodide suggested the unfolding of the molecule due to reduction. Thus, disulfide linkages play a predominant role in maintaining the three-dimensional structure of the inhibitor.

Pyrethroid-impregnated hessian curtains for protection against mosquitoes indoors in south India.

Hessian curtains impregnated with deltamethrin 50 mg/m2 were hung in the eaves and doorways of eight one-roomed huts in Madurai, Tamil Nadu State, South India. Statistically significant reductions of indoor-resting and man-biting densities of the mosquitoes Anopheles subpictus and Culex quinquefasciatus were observed for 14 weeks, in two field trials. Bioassays on curtains in the field showed over 50% mortality of Cx quinquefasciatus and An.stephensi for up to 8 weeks. The curtains were highly acceptable to the community, and cost approximately Rs.33.15 (US$1.05) for material and Rs.10 ($0.32) for delta-methrin per hut, totalling Rs 53.15 ($1.70) for two impregnations giving 6 months protection. Comparative costs of house-spraying with residual insecticides are estimated as Rs.1.92 ($0.06) for two rounds of DDT at 1 g/m2, or Rs.40 ($1.27) for three rounds of malathion at 2 g/m2. Therefore the relative annual cost of protection using deltamethrin-impregnated hessian curtains is 28 x or 1.3 x more than for house-spraying with DDT or malathion, respectively (excluding operational expenditure).

Development of a high level of resistance to Bacillus sphaericus in a field population of Culex quinquefasciatus from Kochi, India.

Field resistance to Bacillus sphaericus was observed in a population of Culex quinquefasciatus in Kochi, India, exposed to 35 rounds of spraying with a formulation of B. sphaericus 1593 M over a 2-year period. Larvae from the sprayed area gave LC50 and LC90 values that were 146 and 180 times greater than corresponding values for a susceptible strain from an unsprayed locality. When the resistant strain was colonized in the laboratory and subjected to moderate selection pressure at each generation, resistance rapidly increased and by the 18th generation it was 6,223 and 31,325 times greater at the LC50 and LC90 levels in comparison with the susceptible strain. There were no significant differences among 6 susceptible strains tested. Tests were repeated and validated using the standard primary powder SPH88, B. sphaericus 2362. No cross resistance was observed against B. thuringiensis H-14.

Development of combined use of neem (Azadirachta indica) and water management for the control of culicine mosquitoes in rice fields.

Crude neem products have earlier shown considerable promise for control of culicine mosquito vectors in rice fields as a by-product of their agricultural use as fertilizers, but suffer from disadvantages of bulkiness and lack of stability in storage. Relatively stable lipid-rich fractions of neem were shown to be as effective as good-quality crude neem products in control of breeding of culicine vectors of Japanese encephalitis, and also produced a slight but significant reduction in populations of anopheline pupae. Neem-based formulations coated over urea significantly increased grain yield, but used alone did not, whereas combining the use of neem-coated urea and water management by intermittent irrigation had a greater effect on grain yield than that of water management alone. The neem fractions were relatively cost-effective, and the combined water management and neem-coated urea strategy is acceptable to farmers, who are already aware of the benefits of the use of neem-coated urea, and of water management. This technology therefore has considerable promise as an environmentally benign method of rice-field mosquito control that could be sustainably implemented by farmers.

Detection of lectin activity on western blots using erythrocytes.

A method is described for the direct detection of lectins, agglutinating erythrocytes, on nitrocellulose membranes after Western blotting, thus avoiding protein extraction from specific bands in the gel, followed by agglutination assays. The methodology essentially involves exposing the lectin band on a nitrocellulose strip to trypsinized rabbit erythrocytes (2%, in 0.15 M NaCl) for 30 min at 37 degrees C and then carefully transferring the membrane to saline (4 degrees C) for a few gentle washes and then fixing it in a solution (0.2% glutaraldehyde in 0.15 M NaCl) for 30 min. Later, the membrane is gently washed several times in 0.15 M NaCl containing 10 mM beta-alanine. The lectin band is visualized as a red agglutinated patch. The method is specific for lectins that can agglutinate red blood cells and virtually has no cross reactivity with the various nonlectin proteins tested. Binding of erythrocytes to the lectin band on the nitrocellulose strip can be prevented by specific competing sugars. The method can be applied to screen for the presence of lectins in natural materials and to monitor lectin fractions during purification.

Prevalence of lactose maldigestion. Influence and interaction of age, race, and sex.

Ninety-eight adults ranging from 20 to 89 years in age (52 blacks, 46 whites, 48 males, 50 females) were tested for lactose maldigestion by breath hydrogen analysis after consuming milk containing 16.5 g lactose (360 ml milk). Older adults (> or = 50 years) displayed a significantly higher incidence (46%) of lactose maldigestion than younger adults (< 50 years, 26%). In younger adults there were 2.4 times more maldigesters in blacks than in whites, while in older groups this ratio was 3.6. Level of breath hydrogen significantly increased with age up to the age group of 60-69 years. The interaction between age groups and race was highly significant. Of the maldigesters, 63% reported symptoms and 3% of the total sample reported severe symptoms. Results of this study indicate that the prevalance of lactose maldigestion significantly increases with age in blacks compared to whites and that the magnitude of the problem may be greater in black maldigesters than in white maldigesters.

The complete primary structure of a unique mannose/glucose-specific lectin from field bean (Dolichos lab lab).

The complete amino acid sequence of two non-identical subunits of the glucose/mannose-specific lectin from Dolichos lab lab (field bean) has been determined by sequential Edman analyses of the intact subunits and peptides derived by enzymatic and chemical cleavage. Peptides were purified by reverse phase high performance liquid chromatography and ion pair chromatography. The D. lab lab lectin is a glycoprotein having two polypeptide chains of 132 and 105 amino acid residues. The amino acid sequence of the D. lab lab lectin is compared with the various lectins of the family Leguminosae. The D. lab lab lectin is the only species of the tribe Phaseoleae that contains two nonidentical subunits of almost equal size and that shows a specificity to glucose/mannose. The lectin shows a greater homology to the glucose/mannose-specific lectins, especially concanavalin A. The unique subunit architecture of the D. lab lab lectin indicates the presence of new post-translational cleavage sites.