Practice patterns and outcomes with the use of regorafenib in metastatic colorectal cancer: Results from the Regorafenib in Metastatic colorectal cancer - An Indian exploratory analysis study.

BACKGROUND: Regorafenib is considered a standard of care as third-line therapy in metastatic colorectal cancers (mCRCs). MATERIALS AND METHODS: The study was based on a computerized clinical data form sent to oncologists across the country for entry of anonymized patient data. The data entry form was conceived and generated by the coordinating center's (Tata Memorial Hospital) gastrointestinal medical oncologists and disseminated through personal contacts at academic conferences as well as through E-mail to various oncologists across India. RESULTS: A total of 19 physicians contributed data resulting in 80 patients receiving regorafenib who were available for the evaluation of practice patterns. The median age was 55 years (range: 24-75). Majority had received oxaliplatin-based (97.5%), irinotecan-based (87.5%), and targeted therapy (65%), previously. Patients were primarily started on reduced doses of regorafenib upfront (160 mg - 28.8%, 120 mg - 58.8%, and 80 mg - 12.5%). The median duration of treatment (treatment duration) with regorafenib was 3.1 months (range: 0.5-18), while the median progression free survival was 3.48 months (range: 2.6-4.3). Forty-five percent of patients required dose modifications due to toxicities, and the most common were (all grades) hand-foot syndrome (68.8%), fatigue (46.3%), mucositis (37.6%), and diarrhea (31.3%). CONCLUSIONS: Majority of physicians in this collaborative study from India used a lower dose of regorafenib at the outset in patients with mCRC. Despite a lower dose, there was a significant requirement for dose reduction. Duration of treatment with regorafenib as an efficacy end point in this study is similar to available data from other regions as it is the side effect profile.

Regulation by testosterone of the glucosamine-6-phosphate synthase activity in the male reproductive organs of rat.

Accessory reproductive organs of male rat were found to contain high activities of glucosamine-6-phosphate synthase (glucosaminephosphate isomerase (glutamine-forming), EC 5.3.1.19). Castration caused drastic reduction (75%) in the enzyme activity of ventral prostate. Testosterone propionate administration restored the enzyme activity while cortisol and estradiol-17 beta did not cause any effect. Cycloheximide blocked the stimulation caused by testosterone.

Quantitative aspects of metal ion binding to certain transfer RNA anticodon loop modified nucleosides.

Magnesium and manganese ions bind strongly to the unusual transfer RNA anticodon loop nucleotides, N-[(9-beta-D-ribofuranosyl-9H-purin-6-yl)carbamoyl]-L-threonine 5'-monophosphate (pt6A) and uridine-5-oxyacetic acid 5'-monophosphate (pV). Potentiometric measurements have shown that the delta G for metal ion-pt6A complex formation is 2-3-times more exothermic than for AMP. Electron-nuclear longitudinal dipolar relaxation data yielded manganese-ligand atom distances which permit a three-dimensional construct of the complex in which metal is coordinated to the phosphate, carboxylate of the threonine side-chain (with the nucleotide in the anti glycosidic conformation) and N7 of the adenine ring. Similarly, manganese binds strongly to pV, involving phosphate and carboxylate functions. It is possible that a facet of the functional role of these unusual residues is to chelate magnesium ions and in so doing permit optimum anticodon loop conformational stability and stability of tRNA-mRNA-ribosome complexes.

Novel functional association of rat testicular membrane-associated cytosolic glutathione S transferases and cyclooxygenase in vitro.

AIM: To analyze the role of cytosolic glutathione S-transferases cGSTs and membrane-associated cytosolic GSTs macGSTs in prostaglandin biosynthesis and to evaluate the possible interaction between glutathione S-transferases GSTs and cyclooxygenase (COX) in vitro. METHODS: SDS-PAGE analysis was undertaken for characterization of GSTs, thin layer chromatography (TLC) to monitor the effect of GSTs on prostaglandin biosynthesis from arachidonic acid (AA) and spectrophotometric assays were done for measuring activity levels of COX and GSTs. RESULTS: SDS-PAGE analysis indicates that macGSTs have molecular weights in the range of 25-28 kDa. In a coupled assay involving GSTs, arachidonic acid and cyclooxygenase-1, rat testicular macGSTs produced prostaglandin E2 and F2alfa, while the cGSTs caused the generation of prostaglandin D2, E2 and F2alfa. In vitro interaction studies on GSTs and COX at the protein level have shown dose-dependent inhibition of COX activity by macGSTs and vice versa. This effect, however, is not seen with cGSTs. The inhibitory effect of COX on macGST activity was relieved with increasing concentrations of reduced glutathione (GSH) but not with 1-chloro 2,4-dinitrobenzene (CDNB). The inhibition of COX by macGSTs, on the other hand, was potentiated by glutathione. CONCLUSION: We isolated and purified macGSTs and cGSTs from rat testis and analyzed their involvement in prostaglandin biosynthesis. These studies reveal a reversible functional interaction between macGSTs and COX in vitro, with possible interactions between them at the GSH binding site of macGSTs.

Baseline body mass index among children and adults undergoing allogeneic hematopoietic cell transplantation: clinical characteristics and outcomes.

Obesity is an important public health problem that may influence the outcomes of hematopoietic cell transplantation (HCT). We studied 898 children and adults receiving first-time allogeneic hematopoietic SCTs between 2004 and 2012. Pretransplant body mass index (BMI) was classified as underweight, normal weight, overweight or obese using the WHO classification or age-adjusted BMI percentiles for children. The study population was predominantly Caucasian, and the median age was 51 years (5 months-73 years). The cumulative 3-year incidence of nonrelapse mortality (NRM) in underweight, normal weight, overweight and obese patients was 20%, 19%, 20% and 33%, respectively. Major causes of NRM were acute and chronic GVHD. The corresponding incidence of relapse was 30%, 41%, 37% and 30%, respectively. Three-year OS was 59%, 48%, 47% and 43%, respectively. Multivariate analysis showed that obesity was associated with higher NRM (hazard ratio (HR) 1.43, P=0.04) and lower relapse (HR 0.65, P=0.002). Pretransplant plasma levels of ST2 and TNFR1 biomarkers were significantly higher in obese compared with normal weight patients (P=0.04 and P=0.05, respectively). The increase in NRM observed in obese patients was partially offset by a lower incidence of relapse with no difference in OS.

Novel antidiabetic and hypolipidemic agents. 3. Benzofuran-containing thiazolidinediones.

Several thiazolidinedione derivatives having 5-hydroxy-2,3-dihydro-2, 2,4,6,7-pentamethylbenzofuran moieties and their 5-benzyloxy derivatives and 5-hydroxy-2,4,6,7-tetramethylbenzofuran moieties were synthesized and evaluated in db/db mice. Insertion of an N-Me group into the linker between thiazolidinedione and substituted benzofuran pharmacophores showed considerable improvement in their euglycemic activity. Further improvement has been observed when a pyrrolidine moiety is introduced in the structure to give 5-[4-[N-[3(R/S)-5-benzyloxy-2,3-dihydro-2,2,4,6, 7-pentamethylbenzofuran-3-ylmethyl]-(2S)-pyrrolidin-2- ylmethoxy]pheny lene]thiazolidine-2,4-dione (21a). At a 100 mg/kg/day dose of the maleate salt, compound 21a reduced the plasma glucose and triglyceride to the level of lean littermate, i.e. 8 +/- 1 mM, and is the most potent and efficacious compound reported in this series.

Glycoprotein glycosyltransferases in male reproductive organs and their hormonal regulation.

The prostate glands of rats, mice, guinea pigs and hamsters were found to be a rich source of enzymes catalyzing the Mn2+-dependent transfer of galactose from UDP-galactose to glycoprotein acceptors such as ovomucoid and ovalbumin. The ventral prostate was also very active in promoting transfer of fucose from GDP-fucose to ovomucoid. The prostatic enzymes promoting both galactosyl and fucosyl transfers to glycoproteins were very largely membrane-bound, and were markedly activated by the non-ionic detergent Triton X-100. Castration of adult male resulted in a many-fold and roughly parallel decline in both glycosyltransferase activities over a period of two weeks, which was reversed by subsequent daily treatment with testosterone for 8 days. The very low galactosyltransferase of the ventral prostate of hypophysectomized rats was markedly enhanced by testosterone administration, whereas prolactin alone or in combination with androgen had no significant effect.

Conjunctival goblet cells and mitotic rate in children with retinol deficiency and measles.

To study the effect of retinol deficiency and measles on the conjunctival epithelium, we determined the epithelial mitotic rate (MR) and goblet cell frequency (GCF) in conjunctival biopsy specimens from preschool children in Hyderabad, India. We studied three groups of children: normal appearing, clinically retinol deficient (defined by the presence of superficial fine punctate keratitis), and clinically retinol deficient with measles. The last group was subdivided into those with low serum retinol levels (less than or equal to 20 micrograms/dL [less than or equal to mumol/L]) and those with normal serum retinol levels (greater than 20 micrograms/dL [greater than 0.70 mumol/L]). In the control group of seven normal-appearing children with a mean age of 4.6 years, the mean MR was 1.3% +/- 0.4%, and the mean GCF was 8.0% +/- 3.6% of the basal epithelial cells. In seven children with clinical retinol deficiency, the mean MR was 15.4% +/- 1.2%, and the mean GCF was 1.0% +/- 0.5%, values significantly different from normal ones. Among 11 children with clinical retinol deficiency, measles, and low serum retinol levels, the mean MR was 9.0% +/- 1.9%, and the mean GCF was 3.1% +/- 1.1%, values not statistically different from those in children with clinical retinol deficiency alone. Five children with clinical retinol deficiency, measles, and normal serum retinol levels had a mean MR of 10.2% +/- 3.7% and a mean GCF of 1.9% +/- 1.7%, values similar to those in the other disease groups. This indicates that retinol deficiency sufficient to cause clinical signs without subepithelial scarring or keratinization is associated with hyperproliferation of the conjunctiva whether or not there is a superimposed measles infection.

Effect of 2',4'-dichlorobenzamil hydrochloride, a Na(+)-Ca(2+) exchange inhibitor, on human spermatozoa.

The present study is aimed to investigate the contact spermicidal efficacy of 2',4'-dichlorobenzamil hydrochloride (DBZ), a Na(+)-Ca(2+) exchange inhibitor, on ejaculated human spermatozoa. The drug produced a dose- and time-dependent spermicidal action on human spermatozoa. A concentration of 4 mM produced total loss of sperm viability within 1 min of addition to total semen. On the other hand, a similar action on spermatozoa separated from semen was noted at 0.5 mM concentration. The loss of spermatozoal viability was accompanied with an increase in intracellular Ca(2+). Sperm revival testing with glucose suggested a spermicidal rather than a spermiostatic action.

Superoxide anions and other components of human renal adenocarcinoma.

The levels of superoxide anion production, cytochrome P450, ornithine decarboxylase(E.C.4.1.1.17), catalase(E.C.1.11.1.6), deoxyribonucleic acid, ribonucleic acid and protein have been studied in human kidney and renal clear-cell adenocarcinoma tissues. The levels of superoxide anion production, ornithine decarboxylase, catalase and ribonucleic acid in the tumor tissue are very different from those in the kidney.

Desensitization of ornithine decarboxylase activity to norepinephrine in the testis of rat.

Injection of norepinephrine (NE) at a dose of 10 micrograms per testis caused the testis refractory in terms of ornithine decarboxylase (ODC) activity at 24 h. This desensitization was found to be both time and dose dependent. Injection with follicle stimulating hormone, luteinizing hormone, prostaglandin F2 alpha, cyclic AMP or epinephrine to norepinephrine desensitized testis caused stimulation of ODC activity. This indicates that the refractoriness caused by norepinephrine is specific to this agent alone.

Direct inhibitory effect of gonadotropin releasing hormone in the uterus of rat.

Estradiol induced increase in ornithine decarboxylase (ODC) and glucosamine-6-phosphate synthase activities of rat uterus were inhibited by simultaneous treatment with gonadotropin releasing hormone (GnRH) or its agonists. The direct inhibitory effect of GnRH analogs was found to be dose dependent. It was observed that a higher dose of GnRH analog was needed to cause inhibition of glucosamine-6-phosphate synthase when compared to ODC activity. The inhibitory effect of GnRH was not observed if its injection was delayed following estradiol treatment. These results show that the extra-pituitary inhibitory effects of GnRH involves enzymes associated with cell proliferation.

Androgen regulation of poly(A) polymerase in the ventral prostate of rat.

The effect of various hormones on the levels of poly(A) polymerase in the ventral prostate of castrated rats was investigated. It was observed that this enzyme is specifically induced by androgens; progesterone and estradiol-17 beta did not cause stimulation of poly(A) polymerase activity. Dihydrotestosterone-induced poly(A) polymerase was inhibited by cordycepin, actinomycin-D and cycloheximide, which indicates that the genetic transcription leading to the enzyme poly(A) polymerase is regulated by androgens in the ventral prostate.

Effect of estradiol and progesterone on glucosamine 6-phosphate synthase in the uterus of rat.

Injection of estradiol to ovariectomised rats caused significant increase in the activity of glucosamine 6-phosphate synthase of uterus. Progesterone did not cause any increase in the activity of the enzyme; however, it antagonised the effect of estradiol. It was observed that the enzyme is predominantly localised in the endometrium of uterus.

Alpha-difluoromethylornithine as a postcoitally effective antifertility agent in female rats.

Intraperitoneal injection of alpha-difluoromethylornithine (DFMO) at a dose of 200 mg/kg, twice a day, during days 4-7 of pregnancy caused inhibition of embryogenesis in rats. These animals did not deliver any pups at term. However, there was no effect of DFMO on pregnant rats following treatment during day 1-3 of pregnancy. It was observed that DFMO completely abolished ornithine decarboxylase levels in the pregnant uterus. The action of DFMO appears to be due to the inhibition of putrescine and polyamines during a critical period of early embryo development. We suggest that this drug may act as a postcoitally effective antifertility agent in females.

Guar gum as a carrier for colon specific delivery; influence of metronidazole and tinidazole on in vitro release of albendazole from guar gum matrix tablets.

PURPOSE: The present investigation is to study the influence of metronidazole and tinidazole on the usefulness of guar gum, a colon-specific drug carrier based on the metabolic activity of colonic bacteria, using matrix tablets of albendazole (containing 20% of guar gum) as a model formulation. METHODS: The matrix tablets of albendazole were subjected to in vitro drug release studies in simulated colonic fluids (4%w/v of rat caecal contents) obtained after oral treatment of rats for 7 days either with varying doses of metronidazole/ tinidazole and 1 mL of 2%w/v of guar gum or with 1 mL of 2%w/v of guar gum alone (control study) after completing the dissolution study in 0.1 M HCl (2 h) and pH 7.4 Sorensen's phosphate buffer (3 h). RESULTS: The guar gum matrix tablets of albendazole were found degraded by colonic bacteria of rat caecal contents and released about 44% of albendazole in simulated colonic fluids (control study) at the end of 24 h indicating the susceptibility of the guar gum formulations to the rat caecal contents. However, the release of albendazole decreased when the drug release studies were carried out in caecal contents of rats treated for 7 days with either metronidazole (10-50 mg/ kg once daily) or tinidazole (10-30 mg/ kg once daily), and the release of albendazole from the matrix tablets was found to be dose dependent. The release of the drug from guar gum formulations was found to increase with a decrease in the dose of metronidazole/tinidazole administered. The antimicrobial activity of metronidazole/ tinidazole against the anaerobic bacteria of the rat"s GI flora might have been inhibited to a varying degree depending on the dose of metronidazole/tinidazole administered. CONCLUSIONS: The results of the study showed that concomitant administration of either metronidazole or tinidazole with guar gum based colon-specific drug delivery systems may interfere with the targeting of drugs to colon.

Hormonal contraception for human males: prospects.

Development of an ideal hormonal contraceptive for man has been the goal of several research workers during the past few decades. Suppression of pituitary gonadotropic hormones, which in turn would inhibit spermatogenesis while maintaining normal libido and potential has been the approach for a contraceptive agent. Intramuscularly administered and orally active testosterone or testosterone in combination with progesterone have been shown to cause inhibition of spermatogenesis resulting in azoospermia in normal men. Similarly testosterone has been used in combination with gonadotropin releasing hormone antagonists and agonists to inhibit pituitary gonadotropic hormone release. Immunological approach to neutralize the circulating levels of follicle stimulating hormone has also been shown to cause inhibition of spermatogenesis. The available literature shows that testosterone causes reversible azoospermia without any significant side effects in Asian population effectively and appears to be a promising chemical for control of fertility in man.

Purification and characterization of rat testicular glutathione S-transferases: role in the synthesis of eicosanoids.

AIM: Purification of glutathione S-transferases (GSTs) from rat testis; separation and identification of various subunits and their role in eicosanoid biosynthesis. METHODS: Purification of rat testicular GSTs by affinity chromatography, employing S-hexylglutathione-linked epoxy-activated Sepharose 6B column and separation of individual subunits by reverse phase-high pressure liquid chromatography (RP-HPLC). Characterization of affinity purified GSTs by Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis. The role of testicular GSTs in eicosanoid biosynthesis was determine by incubating GSTs with 5, 6-Leukotriene A4Me (LTA4Me) and prostaglandin H2(PGH2) and analyzing the products formed on HPLC/TLC. RESULTS: The present study reveals that majority of rat testicular GSTs are of Yb size (60%) with molecular weight of 27 kDa. The most predominant subunits, however, are GST Yn2(27%), followed by GST Yc(24%) and GST Yn1(20%). These testicular GSTs showed very high Leukotriene C4 (LTC4) synthase activity with 5, 6-Leukotriene A4Me (LTA4Me) as the substrate and prostaglandin D (PGD) synthase activity with prostaglandin H2(PGH2) as the substrate. CONCLUSION: Majority of rat testicular GSTs are Yb sized and are involved in the synthesis of eicosanoids like LTC4 and PGD2.

Studies on the development of oral colon targeted drug delivery systems for metronidazole in the treatment of amoebiasis.

The aim of the present study is to develop colon targeted drug delivery systems for metronidazole using guar gum as a carrier. Matrix, multilayer and compression coated tablets of metronidazole containing various proportions of guar gum were prepared. All the formulations were evaluated for the hardness, drug content uniformity, and were subjected to in vitro drug release studies. The amount of metronidazole released from tablets at different time intervals was estimated by high performance liquid chromatography method. Matrix tablets and multilayer tablets of metronidazole released 43-52% and 25-44% of the metronidazole, respectively, in the physiological environment of stomach and small intestine depending on the proportion of guar gum used in the formulation. Both the formulations failed to control the drug release within 5 h of the dissolution study in the physiological environment of stomach and small intestine. The compression coated formulations released less than 1% of metronidazole in the physiological environment of stomach and small intestine. When the dissolution study was continued in simulated colonic fluids, the compression coated tablet with 275 mg of guar gum coat released another 61% of metronidazole after degradation by colonic bacteria at the end of 24 h of the dissolution study. The compression coated tablets with 350 and 435 mg of guar gum coat released about 45 and 20% of metronidazole, respectively, in simulated colonic fluids indicating the susceptibility of the guar gum formulations to the rat caecal contents. The results of the study show that compression coated metronidazole tablets with either 275 or 350 mg of guar gum coat is most likely to provide targeting of metronidazole for local action in the colon owing to its minimal release of the drug in the first 5 h. The metronidazole compression coated tablets showed no change either in physical appearance, drug content or in dissolution pattern after storage at 40 degrees C/75% RH for 6 months.

Effect of various flours on the production of thermostable beta-amylase and pullulanase by Clostridium thermosulfurogenes SV2.

The effects of various flours on production of thermostable beta-amylase and pullulanase using Clostridium thermosulfurogenes SV2 was studied in submerged fermentation. Among the flours added to PYE basal medium, potato flour was the best substrate for enzyme production, and under optimal conditions C. thermosulfurogenes SV2 produced 0.87 and 0.98 U of thermostable beta-amylase and pullulanase, respectively, per ml culture broth.