Simultaneous Determination of Vincristine, Vinblastine, Catharanthine, and Vindoline in Leaves of Catharanthus roseus by High-Performance Liquid Chromatography

A simple reversed-phase liquid chromatographic method is developed for the simultaneous quantitation of the anticancerous drugs vincristine, vinblastine, and their precursors catharanthine and vindoline using a Merck Chromolith Performance reversed-phase high-performance liquid chromatography column. A better resolution is obtained in comparison with available particulate-type C18 columns. The column provides good reproducibility and peak symmetry. Chromatography is carried isocratically with a mobile phase of acetonitrile-0.1M phosphate buffer containing 0.5% glacial acetic acid (21:79, v/v; pH 3.5) at a flow rate of 1.2 mL/min and UV detection at 254 nm. Parameters such as linearity, limits of quantitation (LOQ) and detection (LOD), precision, accuracy, recovery, and robustness are studied. The method is selective and linear for alkaloid concentration in the range 0.25 microg-25 microg/mL. The LOQ and LOD are 25, 46, 56, and 32 microg/mL and 8, 14, 18, and 10 microg/mL, respectively. The results of accuracy studies are good. Values for coefficient of variation are 2.50, 1.82, 1.33, and 1.13, respectively. The percent recovery of the alkaloids was found to be 96%, 97%, 98%, and 98%, respectively. Peak purity and homogeneity of these compounds in plant extract is studied using a photodiode-array detector. This simple and rapid method of analysis is applied for the determination of these alkaloids in a large number of leaf extracts of Catharanthus roseus..

Arjunetin from Terminalia arjuna as an insect feeding-deterrent and growth inhibitor

Crude ethanolic extract of the stem bark of Terminalia arjuna (Combretaceae) and its three compounds namely arjunic acid, arjungenin and arjunetin were evaluated for antifeedant, growth inhibitory and oviposition-deterrent activities against a lepidopterous insect Spilarctia obliqua. The compound arjunetin showed highest growth inhibitory and feeding-deterrent properties with a growth inhibition (GI(50)) and feeding-inhibition (FD(50)) of 188.5 and 287.1 micro g/g diet respectively. Oviposition bioassays indicated no oviposition-deterrence in any of the compounds tested. The structure-activity relationship study indicated the importance of a glycosidation linkage in arjunetin.

Role of antibiosis in the biological control of spot blotch ( Cochliobolus sativus) of wheat by Chaetomium globosum

Chaetomium globosum Kunze, has been identified as a potential antagonist of Cochliobolus sativus (S. Ito & Kurib.) Deschler ex Dastur. (Syn = Drechslera sorokiniana). Production of antifungal compounds by Chaetomium globosum (Cg) and their role in suppression of spot blotch of wheat caused by this fungus under in vitro and in vivo has been evaluated. Interaction between Chaetomium globosum isolates and C. sativus showed mycoparasitism by isolates Cg 1 and Cg 6 whereas isolates Cg 2, Cg 3, Cg 4 and Cg 5 showed antibiosis. Syringe filtered culture extracts of Cg 2 completely inhibited mycelial growth of C. sativus in liquid broth. In vitro bioassays were undertaken by amending the medium with crude extracts and agar diffusion method in order to assess the fungistatic activity of crude extracts from culture filtrates of different isolates of Chaetomium globosum. Significant differences in antagonism between isolates were observed. Antifungal metabolite profiling, on TLC (Thin Layer Chromatography) plates identified 13 compounds in isolate Cg 2, 11 compounds in Cg 3 and 7 compounds in Cg 6. Isolate Cg 1 produced only two faint bands and Cg 5 produced two bands of the same Rf value but of higher intensity. The production of antifungal compounds by isolates was positively correlated with antagonism to C. sativus on seedlings in glasshouse studies. The results showed high antifungal metabolite production by isolate Cg 2, which also gave maximum bioefficacy under laboratory and glasshouse conditions.

Molecular characterization of Vibrio cholerae O139 bengal isolated from water and the aquatic plant Eichhornia crassipes in the River Ganga, Varanasi, India

A collection of ten strains of Vibrio cholerae O139, comprising six isolates from Eichhornia crassipes, two from water of the River Ganga, and one each from a well and a hand pump, were characterized. All the strains carried the CTX genetic element (ctxA, zot, and ace) except for the st gene and carried structural and regulatory genes for toxin-coregulated pilus (tcpA, tcpI, and toxR), adherence factor (ompU), and accessory colonization factor (acfB); all produced cholera toxin (CT). These strains were resistant to trimethoprim, sulfamethoxazole, streptomycin, and to the vibriostatic agent pteridine. Results obtained by ribotyping and enterobacterial repetitive intergenic consensus sequence-PCR fingerprint analysis indicate that multiple clones of toxigenic-pathogenic V. cholerae O139 were present in the aquatic environment.

Characterization of a toxigenic Vibrio cholerae O139 strain belonging to a new ribotype and isolated from a diarrheal patient

We characterized a Vibrio cholerae O139 strain isolated from a diarrheal patient admitted to Taluk Hospital, Cherthala, Alleppey, Kerala, India, on 9 June 2000. The V. cholerae O139 strain possesses the core of the CTX genetic element, colonization toxin-coregulated pilus, the adherence outer membrane protein, and the central regulatory protein encoded by toxR and produces cholera toxin (200 pg/ml). We provide molecular evidence showing that toxigenic V. cholerae O139 strain ALO95 belongs to a distinct genotype characterized by a unique ribotype designated B-VII and has a unique enterobacterial repetitive intergenic consensus sequence PCR fingerprint profile designated E-V.

Development of a hexaplex PCR assay for rapid detection of virulence and regulatory genes in Vibrio cholerae and Vibrio mimicus

We have developed a hexaplex PCR assay for rapid detection of the virulence and regulatory genes for cholera toxin enzymatic subunit A (ctxA), zonula occludens toxin (zot), accessory cholera enterotoxin (ace), toxin-coregulated pilus (tcpA), outer membrane protein (ompU), and central regulatory protein ToxR (toxR) in Vibrio cholerae and Vibrio mimicus. This hexaplex PCR proved successful in screening pathogenic-toxigenic and nonpathogenic-nontoxigenic V. cholerae and V. mimicus strains from both clinical and environmental sources.

Cranial vault Salmonella osteomyelitis leading to extradural abscess - a case report

A case of rarely encountered Salmonella typhi osteomyelitis of left occipital bone leading to extradural abscess, is reported. The causative organism was not suspected until the culture report was obtained. The patient responded promptly to surgical drainage and antibiotic therapy.

Quantitative determination of oleane derivatives in Terminalia arjuna by high performance thin layer chromatography

A simple, precise and rapid high performance thin layer chromatographic method has been developed for the simultaneous quantitative determination of five oleane derivatives, namely, arjunic acid, arjunolic acid, arjungenin, arjunetin and arjunglucoside I from stem bark extract of Terminalia arjuna. The isolation and separation of these compounds was carried out on 60F254 layers eluted with chloroform:methanol (90:10), and the analytes were visualised through colour development with vanillin in concentrated sulphuric acid:ethanol. Scanning and quantification of the spots at 640 nm showed good recoveries in the range 96.40-101.7%.

RP-LC determination of oleane derivatives in Terminalia arjuna

A rapid sensitive and reproductive reversed phase high performance liquid chromatographic method with photo diode arrray detection is described for the simultaneous quantification of major oleane derivatives: arjunic acid (4), arjunolic acid (3), arjungenin (2) and arjunetin (1) in Terminalia arjuna extract. The method involves the use of a Waters Spherisorb S10 ODS2 column (250 x 4.6 mm, I.D., 10 microm) and binary gradient mobile phase profile. The various other aspects of analysis viz. Extraction efficiency, peak purity and similarity were validated using a photo diode array detector.

Nitrogen and sulphur relations in effecting yield and quality of cereals and oilseed crops

Nitrogen and sulphur, both vital structural elements, are especially needed for the synthesis of proteins and oils. Investigations revealed the required application of sulphur is one half to one third the amount of nitrogen, and the ratio becomes narrower in mustard (Brassica juncea L.), followed by wheat and rice. The efficiency of an increased level of nitrogen required a proportionately higher amount of sulphur. A critical investigation on the effective utilization of applied vis-à-vis absorbed nitrogen in wheat and mustard envisaged accumulation of NO3-N in vegetative parts when sulphur remained proportionately low. Application of sulphur hastened the chemical reduction of absorbed NO3- for its effective utilization. The effect was more pronounced in mustard than in wheat. Easily available forms of sulphur, like ammonium sulphate and gypsum, as compared to pyrite or elemental sulphur, maintained adequate N to S ratio in rice, resulting in a reduction in the percent of unfilled grain, a major consideration in rice yield. A narrow N to S ratio, with both at higher levels, increased the oil content but raised the saponification value of the oil, a measure of free fatty acids. Whereas, a proportionately narrow N to S ratio at moderate dose resulted in adequately higher seed and oil yield with relatively low saponification value, associated with increased iodine value of the oil, indicating respectively low free fatty acids and higher proportion of unsaturated fatty acids, an index for better quality of the oil.

Carbofuran induced impairment in the hypothalamo-neurohypophyseal-gonadal complex in the teleost, Channa punctalus (Bloch)

The effect of chronic exposure to carbofuran (4.5 ppm in static water) for six months on the gonadal histophysiology and hypothalamo-neurohypophyseal complex was studied in Channa punctatus. Experimental observations revealed significant inhibition of gonadal development with associated degenerative abnormalities as evidenced by ovarian and testicular histology and reduced gonadosomatic index. Degenerative changes in ovary were exihibited by stage I (oogonium) and stage II (immature/non-vitellogenic) oocytes as marked by perinuclear ooplasmic lysis, clumping and dissolution resulting in disintigration of nuclear material altogether attributed to complete degeneration of such oocytes. Testicular deleterious changes included degeneration of spermatogenic elements and necrosis of interstitial cells of Leydig. Correlative histophysiological changes were also observed in the pituitary gonadotrophs and hypothalamic, nucleus pre-opticus, neurons that were smaller, inactive and less in number with associated necrosis. Corresponding to the changes in nucleus pre-opticus neurons, significant inhibition of brain monoamine oxidase enzyme activity was also recorded in treated group. These observations suggest that carbofuran even at low concentration level under long-term exposure is capable of inducing retardation of gonadal development which might have been mediated through the impairment of the hypothalamo-neurohypophyseal-gonadal axis in this species.

Molecular analysis of Vibrio cholerae O1, O139, non-O1, and non-O139 strains: clonal relationships between clinical and environmental isolates

A total of 26 strains of Vibrio cholerae, including members of the O1, O139, and non-O1, non-O139 serogroups from both clinical and environmental sources, were examined for the presence of genes encoding cholera toxin (ctxA), zonula occludens toxin (zot), accessory cholera enterotoxin (ace), hemolysin (hlyA), NAG-specific heat-stable toxin (st), toxin-coregulated pilus (tcpA), and outer membrane protein (ompU), for genomic organization, and for the presence of the regulatory protein genes tcpI and toxR in order to determine relationships between epidemic serotypes and sources of isolation. While 22 of the 26 strains were hemolytic on 5% sheep blood nutrient agar, all strains were PCR positive for hlyA, the hemolysin gene. When multiplex PCR was used, all serogroup O1 and O139 strains were positive for tcpA, ompU, and tcpI. All O1 and O139 strains except one O1 strain and one O139 strain were positive for the ctxA, zot, and ace genes. Also, O1 strain VO3 was negative for the zot gene. All of the non-O1, non-O139 strains were negative for the ctxA, zot, ace, tcpA, and tcpI genes, and all of the non-O1, non-O139 strains except strain VO26 were negative for ompU. All of the strains except non-O1, non-O139 strain VO22 were PCR positive for the gene encoding the central regulatory protein, toxR. All V. cholerae strains were negative for the NAG-specific st gene. Of the nine non-ctx-producing strains of V. cholerae, only one, non-O1, non-O139 strain VO24, caused fluid accumulation in the rabbit ileal loop assay. The other eight strains, including an O1 strain, an O139 strain, and six non-O1, non-O139 strains, regardless of the source of isolation, caused fluid accumulation after two to five serial passages through the rabbit gut. Culture filtrates of all non-cholera-toxigenic strains grown in AKI media also caused fluid accumulation, suggesting that a new toxin was produced in AKI medium by these strains. Studies of clonality performed by using enterobacterial repetitive intergenic consensus sequence PCR, Box element PCR, amplified fragment length polymorphism (AFLP), and pulsed-field gel electrophoresis (PFGE) collectively indicated that the V. cholerae O1 and O139 strains had a clonal origin, whereas the non-O1, non-O139 strains belonged to different clones. The clinical isolates closely resembled environmental isolates in their genomic patterns. Overall, there was an excellent correlation among the results of the PCR, AFLP, and PFGE analyses, and individual strains derived from clinical and environmental sources produced similar fingerprint patterns. From the results of this study, we concluded that the non-cholera-toxin-producing strains of V. cholerae, whether of clinical or environmental origin, possess the ability to produce a new secretogenic toxin that is entirely different from the toxin produced by toxigenic V. cholerae O1 and O139 strains. We also concluded that the aquatic environment is a reservoir for V. cholerae O1, O139, non-O1, and non-O139 serogroup strains.

A putative heat-labile enterotoxin expressed by strains of Aeromonas media

Fifteen isolates of Aeromonas media (seven from diarrhoeal stools, four from water and four from superficial skin ulcers of catfish) were examined for enterotoxin production. Ten of these isolates (six diarrhoeal, one from water and three from fish) caused accumulation of fluid in the initial rabbit ileal loop (RIL) tests. Isolates from diarrhoeal stools and fish caused relatively more fluid accumulation than those from water. Those strains that caused little or no fluid accumulation in the initial experiments became enterotoxin producers after one passage through RILs, regardless of source, and also showed gradual enhancement of fluid outpouring after each subsequent passage. Inocula of c. 1 x 10(4) viable cells and 0.25 ml of culture filtrate (CF) caused fluid accumulation similar to that of toxigenic Vibrio cholerae 569B. The enterotoxic factor(s) were inactivated when held at 56 degrees C for 20 min or 65 degrees C for 10 min and showed biological activity over a wide range of pH values. These results suggest that strains of A. media, whether from diarrhoeal stools, water or infected fish, are potentially enterotoxigenic and may have the potential to produce a heat-labile and pH-stable diarrhoeagenic factor in the same way as other known heat-labile and pH-stable enterotoxins.

Production of heat-labile enterotoxin by strains of Aeromonas veronii bv veronii

Three isolates of Aeromonas veronii bv veronii (2 environmental, one blood infection) were examined to see if they produce any enterotoxin and, if so, to determine its characteristics. Two isolates caused fluid accumulation in the initial rabbit ileal loop tests. The other strain did so after a single passage through the rabbit ileal loop. All the isolates showed gradual enhancement of fluid secretion after each subsequent passage. Inocula of 1 x 10(4) viable cells and 0.25 mL of culture filtrate caused fluid accumulation comparable to those of toxigenic Vibrio cholerae 569B. The enterotoxic activity was inactivated at higher temperature, and showed biological activity over a wide range of pH. The only histopathological change observed was depletion of mucous from goblet cells. The findings of the study indicate that strains of A. veronii bv veronii produce a heat-labile, pH-stable diarrhoeagenic factor without causing any damage to the intestinal mucosa.

Infundibulopelvic anatomy and clearance of inferior caliceal calculi with shock wave lithotripsy

PURPOSE

We evaluate the significance of inferior caliceal radiographic anatomy and determine its influence on successful fragmentation and clearance of inferior caliceal calculi with extracorporeal shock wave lithotripsy (ESWL).

MATERIALS AND METHODS

Between November 1996 and February 1998, 88 patients and 90 renal units with single or multiple inferior caliceal calculi of all sizes and composition were treated with ESWL. The size, number and area of calculi, length and width of the stone bearing inferior calix and infundibulopelvic angle were determined on pretreatment excretory urography. The infundibulopelvic angle was measured by 2 methods using the angle between the inferior caliceal infundibular and ureteral axes (angle 1), and between the infundibular and ureteropelvic axes (angle 2). Cases with residual fragments not clearing within 6 months of satisfactory fragmentation after lithotripsy were considered failures.

RESULTS

Overall stone clearance at 6 months was achieved in about 72% of the renal units. Infundibular length was 30 mm. or less in 77% of successful cases and in 64% of failures. Similarly, the smallest infundibular width of 5 mm. or more was found in 75% of successful cases compared to 41% of failures. Angle 1 of 35 degrees or more was observed in 73% of cases with compared to 18% without clearance. Angle 2 of 45 degrees or more was seen in 71% of successful cases compared to 9% of failures. The chances of a patient becoming stone-free with all favorable criteria of infundibular length 30 mm. or less, infundibular width 5 mm. or greater and infundibular ureteropelvic angle 45 degrees or greater was 100% (23 patients).

CONCLUSIONS

Radiographic features of a stone bearing inferior calix and its relation to the renal pelvis can be easily measured on standard excretory urography. An infundibular width of 5 mm. or more and infundibulopelvic angle 1 of 35 degrees or more or angle 2 of 45 degrees or more were statistically significant factors of radiographic anatomy in stone clearance following ESWL. Inferior caliceal length was not statistically significant, although length of 30 mm. or less appeared to be more favorable for stone clearance. The ideal treatment of inferior caliceal calculi in patients with all 3 favorable criteria is ESWL.

Virulence patterns of Aeromonas eucrenophila isolated from water and infected fish

Six isolates of Aeromonas eucrenophila--2 from water and 4 from superficial skin ulcer of cat fish--were examined for haemagglutination, serum sensitivity, chitinase production and enterotoxicity, and correlation, if any, between them; only one strain showed haemagglutination and was inhibited by both D-mannose and L-fucose. All the strains showed resistance to normal human serum, but produced chitinase; one of them elaborated inducible chitinase. All these strains caused fluid accumulation only after 1-4 serial passages through rabbit ileal loops, of which one strain that elaborated inducible chitinase caused significantly more (p < 0.005) fluid accumulation. These observations indicate that there is no correlation between enterotoxicity and haemagglutination and/or serum resistance, and these properties did not change after animal passage. However, a correlation could be observed between elaboration of inducible chitinase and enterotoxin production.

Risk assessment of thyroid follicular cell tumors

Thyroid follicular cell tumors arise in rodents from mutations, perturbations of thyroid and pituitary hormone status with increased stimulation of thyroid cell growth by thyroid-stimulating hormone (TSH), or a combination of the two. The only known human thyroid carcinogen is ionizing radiation. It is not known for certain whether chemicals that affect thyroid cell growth lead to human thyroid cancer. The U.S. Environmental Protection Agency applies the following science policy positions: 1) chemically induced rodent thyroid tumors are presumed to be relevant to humans; 2) when interspecies information is lacking, the default is to assume comparable carcinogenic sensitivity in rodents and humans; 3) adverse rodent noncancer thyroid effects due to chemically induced thyroid-pituitary disruption are presumed to be relevant to humans; 4) linear dose-response considerations are applied to thyroid cancer induced by chemical substances that either do not disrupt thyroid functioning or lack mode of action information; 5) nonlinear thyroid cancer dose-response considerations are applied to chemicals that reduce thyroid hormone levels, increase TSH and thyroid cell division, and are judged to lack mutagenic activity; and 6) nonlinear considerations may be applied in thyroid cancer dose-response assessments on a case-by-case basis for chemicals that disrupt thyroid-pituitary functioning and demonstrate some mutagenic activity. Required data for risk assessment purposes is mode of action information on mutagenicity, increases in follicular cell growth (cell size and number) and thyroid gland weight, thyroid-pituitary hormones, site of action, correlations between doses producing thyroid effects and cancer, and reversibility of effects when dosing ceases.