Blind esophageal brushing offers a safe and accurate method to monitor inflammation in children and young adults with eosinophilic esophagitis

Patients with eosinophilic esophagitis (EoE) require frequent evaluation of mucosal inflammation via endoscopy. Instead of endoscopy, mucosal evaluation in adults with esophageal cancer and candidiasis is achieved using a cytology brush inserted through a nasogastric tube (NGT). We conducted a prospective cross-sectional study in children and young adults scheduled for routine esophagogastroduodenoscopy (EGD) where in Phase 1, we performed esophageal brushing through the endoscope under direct visualization and in Phase 2, we inserted the brush through a Cortrak® NGT prior to endoscopy. Eosinophil-derived neurotoxin (EDN) measured by ELISA in the samples extracted from brushes was validated as the sensitive biomarker. We collected 209 esophageal brushing samples from 94 patients and we found that EDN in brushing samples collected via EGD or NGT was significantly higher in patients having active EoE (n = 81, mean EDN 381 mcg/mL) compared with patients having gastroesophageal reflux disease (n = 31, mean EDN 1.9 mcg/mL, P = 0.003), EoE in remission (n = 47, mean EDN 3.7 mcg/mL, P = 0.003), or no disease (n = 50, mean EDN 1.1 mcg/mL, P = 0.003). EDN at a concentration of ≥10 mcg/mL of brushing sample was found to accurately detect active EoE. NGT brushing did not cause any significant adverse effects. We concluded that blind esophageal brushing using an NGT is a fast, less invasive, safe, and well-tolerated technique compared with EGD to detect and monitor EoE inflammation using EDN as the sensitive biomarker.

RBx 7796: A novel inhibitor of 5-lipoxygenase

OBJECTIVE

To evaluate the pharmacological profile of RBx 7,796, a novel 5-lipoxygenase inhibitor.

MATERIALS AND METHODS

RBx 7,796 was evaluated for 5- lipoxygenase inhibitory potential using human recombinant enzyme and profiled for selectivity against 12 and 15 lipoxygenase. RBx 7,796 was evaluated in cell based assay for inhibition of A23,187 induced LTB(4) release from isolated neutrophils. Ex vivo activity was evaluated for inhibition of A23,187 induced LTB(4) release in blood from treated rats. In vivo efficacy of RBx 7,796 was profiled in LPS induced neutrophilia model in rats and also in ovalbumin induced bronchoconstriction and airway inflammation models in guinea pigs.

RESULTS

RBx 7,796, a novel chemotype, showed competitive inhibition of 5-lipoxygenase enzyme with an IC(50) of 3.5 +/- 1.1 microM. RBx 7,796 offered >100 fold selectivity against other related enzymes - 12 and 15 lipoxygenase. RBx 7,796 inhibited release of LTB(4) from human and rat neutrophils in vitro. Upon administration to rats, RBx 7,796 inhibited A23,187 induced LTB(4) release from rat neutrophils. Upon repeated administration, dosed once daily, RBx 7,796 inhibited LPS induced neutrophil influx in rat airway. RBx 7,796 also inhibited allergen induced bronchoconstriction and eosinophil influx in guinea pig airway in a dose dependent manner.

CONCLUSION

The results suggest that RBx 7,796, a novel chemotype, is an orally efficacious inhibitor of 5-lipoxygenase enzyme that is effective against both neutrophilic and eosinophilic airway inflammation and shows potent inhibition with once daily administration.

Reduction of hematotoxicity and augmentation of antitumor efficacy of cyclophosphamide by dopamine

Modulatory effects of dopamine (DA) on hematotoxicity and antitumor efficacy of cyclophosphamide (CY) were studied in Swiss mice bearing transplantable Ehrlich ascites carcinoma (EAC). DA was administered i.p. at a dose of 50 mg/kg/day for 5 consecutive days beginning day 3 after tumor transplantation. CY (200 mg/kg i.p.) was injected 24 hour after completion of DA treatment. DA pretreatment reduced the suppressive effects of CY on hemoglobin, RBC, total WBC, neutrophil, platelet, and bone marrow nucleated cell counts. Likewise, DA partially prevented the CY-induced fall in pluripotent (CFU-S12) and lineage-specific stem cells for granulocytes (CFU-C) in bone marrow. Moreover, mice receiving a combination of DA and CY illustrated greater reduction in tumor volume, viable tumor cell count and mitotic index along with upregulation of tumor cell apoptosis than CY-only group. As a result, the former group demonstrated prolonged hosts survival. Thus, DA protected to a great extent the hematopoietic cells of tumor bearing hosts from the suppressive action of CY and concomitantly augmented its antitumor efficacy resulting in improved hosts survival.

Decrease in platelet serotonin level in uterine cervix cancer patients

Platelet serotonin (5-HT) concentration was measured by HPLC with electrochemical detection in 46 women suffering from cancer of the uterine cervix and 16 matched controls. About 53% reduction (p < 0.05) was recorded in platelet 5-HT level in cancer patients against a control value of 1.29 +/- 0.16 (mean +/- S.E.) nmol per 10(9) platelets. Depletion of intraplatelet 5-HT was positively correlated with clinical stage of the disease although a modest rise (p > 0.05) in platelet 5-HT was observed in patients at stage I. Serotonin release from platelets following activation with thrombin was considerably increased in cancer patients (38.2% compared to 17.4% in controls). The results demonstrate progressive depletion of intraplatelet 5-HT in cervical cancer patients. In addition, their platelets release more 5-HT than the controls upon activation by thrombin.

A soxA gene, encoding a diheme cytochrome c, and a sox locus, essential for sulfur oxidation in a new sulfur lithotrophic bacterium

A mobilizable suicide vector, pSUP5011, was used to introduce Tn5-mob in a new facultative sulfur lithotrophic bacterium, KCT001, to generate mutants defective in sulfur oxidation (Sox(-)). The Sox(-) mutants were unable to oxidize thiosulfate while grown mixotrophically in the presence of thiosulfate and succinate. The mutants were also impaired in oxidizing other reduced sulfur compounds and elemental sulfur as evident from the study of substrate oxidation by the whole cells. Sulfite oxidase activity was significantly diminished in the cell extracts of all the mutants. A soxA gene was identified from the transposon-adjacent genomic DNA of a Sox(-) mutant strain. The sequence analysis revealed that the soxA open reading frame (ORF) is preceded by a potential ribosome binding site and promoter region with -10- and -35-like sequences. The deduced nucleotide sequence of the soxA gene was predicted to code for a protein of 286 amino acids. It had a signal peptide of 26 N-terminal amino acids. The amino acid sequence showed similarity with a putative gene product of Aquifex aeolicus, soluble cytochrome c(551) of Chlorobium limicola, and the available partial SoxA sequence of Paracoccus denitrificans. The soxA-encoded product seems to be a diheme cytochrome c for KCT001 and A. aeolicus, but the amino acid sequence of C. limicola cytochrome c(551) revealed a single heme-binding region. Another transposon insertion mutation was mapped within the soxA ORF. Four other independent transposon insertion mutations were mapped in the 4.4-kb soxA contiguous genomic DNA region. The results thus suggest that a sox locus of KCT001, essential for sulfur oxidation, was affected by all these six independent insertion mutations.

Cloning and characterization of a high-copy-number novel insertion sequence from chemolithotrophic Thiobacillus ferrooxidans

Two distinct families of repetitive DNA elements (1.4 and 1.2 kb) were identified from S1 nuclease-treated genomic DNA of four strains of Thiobacillus ferrooxidans. The 1.4-kb fragment hybridized with IST2, an insertion sequence of T. ferrooxidans. The 1.2-kb fragment was cloned and sequenced. The sequence (IST445), 1219 bp in length, with features characteristic of an insertion element, has a terminal inverted repeat of 8 bp, which can be further extended to 23 or 48 bp with 9 and 26 mismatches, respectively. It displays 54.4% identity in 967 nucleotides of overlap with ISAE1 of Alcaligenes eutrophus. The IST445 contains three open reading frames which have codon usage almost similar to 56 different coding genes of T. ferrooxidans. In Southern blots of restricted genomic DNAs probed with IST445, each of the several strains of T. ferrooxidans gives a distinctive fingerprint. IST445 is present in the range of 10-20 copies per genome in the four strains studied.

Mitomycin C induced inhibition of adrenal steroidogenesis in female rats

Mitomycin C (MC), an antibiotic which depresses DNA synthesis causes suppression of enzyme delta 5 3 beta-hydroxysteroid dehydrogenase (delta 5 3 beta OHD) and glucose-6 phosphate dehydrogenase (G-6 PD) in the rat adrenal tissue. The treatment resulted in a fall in DNA content together with an accumulation of cholesterol and ascorbic acid in the gland. The results suggest a diminution in adrenal steroid biogenesis similar to gonadal inhibition previously reported.

Suppressive effect of quinalphos on the activity of accessory sex glands and plasma concentrations of gonadotrophins and testosterone in rats

Biochemical estimation of prostatic acid phosphatase and fructose content in accessory sex glands, along with radioimmunoassay of plasma gonadotrophins (FSH and LH) and testosterone were performed in Wistar rats following treatment with quinalphos, an organophosphorus insecticide, for 13 and 26 days. Prostatic acid phosphatase activity and fructose content of the accessory sex glands, and plasma levels of testosterone and FSH were significantly lower in all rats treated with quinalphos. However, the degree of inhibition was more extensive in the 26 day-treatment group who, in addition also exhibited a significant reduction in relative weights of the testes and accessory sex organs, and plasma levels of LH. All these adverse effects of quinalphos were prevented when exogenous HCG was administered in concomitant with the insecticide for 26 days. These results suggest that quinalphos may exert a suppressive effect on the functional activity of accessory sex glands by decreasing testicular testosterone production following inhibition of pituitary gonadotrophins release.

Effect of aldrin on accessory sex glands and plasma testosterone levels in rats

The effects of aldrin, an organochlorine insecticide, on accessory sex glands and plasma testosterone levels in rats were studied. The aldrin was administered i.p. for 13 days and 26 days at a dose of 150 micrograms/kg. Relative weights of prostate, seminal vesicles and coagulating glands were significantly decreased in the treated rats compared to those in controls. In addition, there was a significant fall in acid phosphatase activity in prostate and fructose content in accessory sex glands was also observed in treated animals. Plasma testosterone values showed a decrease with the duration of treatment. HCG supplementation with aldrin treatment prevented all those untoward effects of aldrin in experimental rats.

Effect of aldrin on spermatogenesis, plasma gonadotrophins and testosterone, and testicular testosterone in the rat

Quantitative evaluation of the different varieties of germ cells at stage VII of the seminiferous epithelium cycle, namely type-A spermatogonia (ASg), preleptotene spermatocytes (pLSc), mid-pachytene spermatocytes (mPSc) and step 7 spermatids (7Sd), along with radioimmunoassay of plasma gonadotrophins (FSH and LH), testosterone and testicular testosterone were performed in Wistar rats following treatment with aldrin (polycyclic chlorinated hydrocarbon insecticide) for approximately one (13 days) or two cycles (26 days) of the seminiferous epithelium. Extensive degeneration of all varieties of germ cells at stage VII, reduction in the sperm count and significant reductions in plasma concentrations of LH and testosterone were observed following aldrin treatment. The reduction in plasma concentrations of FSH was statistically significant only after treatment for two cycles. The inhibitory effect of aldrin on plasma gonadotrophins, testosterone levels, testicular testosterone content and numbers of 7Sd and ASg was maximum after treatment for two cycles. Administration of human chorionic gonadotrophin along with aldrin treatment for two cycles partially prevented the degeneration of germ cells and enhanced testosterone production. The results indicate that aldrin may have a direct inhibitory influence on gonadotrophin release, but the possibility of a direct action of the insecticide at the level of the testes is also discussed.

Effect of quinalphos on testicular steroidogenesis in rats

The effect of quinalphos (250 micrograms/kg i.p.) an organophosphorus insecticide treatment for 13 and 26-days on the testicular steroidogenic enzymes viz. 3 beta-Hydroxysteroid Dehydrogenase and 17 beta-Hydroxysteroid Dehydrogenase, as well as cholesterol content and histology of the testes of the Wistar strain rats was studied. The time duration of 13 days is approximately equivalent to one cycle of the seminiferous epithelium in Wistar strain rats. Treatment of quinalphos for 13 days failed to produce any effect on the relative weights of the testes and accessory sex glands. However, significant inhibition of 3 beta-HSD activity and increased cholesterol level in testis were observed. The rats treated for 26 days similarly showed a highly significant inhibition of the activity of both 3 beta-HSD and 17 beta-HSD. The relative weights of the testes and accessory sex glands were also significantly reduced. Histological examination of the testis revealed that quinalphos treatment produced detrimental changes in the seminiferous epithelium. Treatment with quinalphos for 13-days produced no toxic effect with the exception of a significant increase in serum alkaline phosphatase. However, after 26-days of treatment toxicity was significantly increased as reflected on serum transaminases, phosphatases and blood urea levels of rat. Present study indicated that quinalphos impairs testicular functions in rats.

Suppression of testicular steroidogenesis in rats by the organochlorine insecticide Aldrin

Treatment with Aldrin, an organochlorine insecticide, for 13 and 26 days caused suppression of 3beta-hydroxysteroid dehydrogenase (3beta-HSD) and 17beta-hydroxysteroid dehydrogenase (17beta-HSD) activities, along with accumulation of cholesterol in the testicular tissues of adult rats. The same treatment also resulted in a reduction in the nuclear diameter of Leydig cells (LCND) and diameter of seminiferous tubules. A decrease in the weight of testes, seminal vesicles and ventral prostate was also noted. HCG administration in the long-term (26 days) treatment restored the steroidogenic enzymes activity and the nuclear diameter of the Leydig cells. It also reduced the accumulation of tissue cholesterol towards the vehicle-injected controls. The inhibition of steroidogenesis in the testes possibly reflects a decrease in pituitary gonadotrophin release after the treatment with Aldrin.

Possible role of pituitary in Mitomycin C induced inhibition of testicular steroidogenesis

To find out the role of pituitary in Mitomycin C (MC) induced reduction of testicular steroidogenesis, MC was administered along with HCG and the testicular steroidogenic activity was assessed on the basis of different parameters which are directly and indirectly related to the rate of testicular steroid biogenesis. The results indicate that MC induced reduction in testicular steroidogenesis is not only due to its direct effect but suppression of pituitary gonadotrophin secretion may be one of the responsible factor.

A histochemical study of leucine amino peptidase activity in the testes of immature and mature guinea-pigs

The distribution of the enzyme leucine amino peptidase (LAP) has been studied histochemically in immature and mature guinea-pig testes. Immature guinea-pig testis showed a very feeble LAP activity, while in mature ones strong LAP activity was noted. The present communication indicates a direct relationship between the activity of the enzyme LAP and sexual maturation.

Action of mitomycin C on testicular steroidogenesis and its probable mode of action in albino rats

Testicular steroidogenesis was determined by radioimmuno assay of serum testosterone and histochemical demonstration of the key steroidogenic enzyme (delta 5 3 beta hydroxysteroid dehydrogenase) activity in the Leydig cells after treatment with mitomycin C (mc), (500 microgram/kg, Bwt). In vivo experiments showed mc treatment causes a remarkable fall of serum testosterone level along with significant reduction in the weights of testis and sex accessories. In vitro studies resulted in a diminution in the delta 5 3 beta hydroxysteroid dehydrogenase and glucose-6-phosphate dehydrogenase activity in the section of the testis after addition of mc (100, 200 microgram/ml) in the incubation medium. The consideration of the above findings coroborated to the suggestion that mc reduced testicular steroidogenesis.

Action of mitomycin C on testicular steroidogenesis in immature rats

Treatment with mitomycin C resulted in a decrease in the testicular delta 5-3 beta-hydroxysteroid dehydrogenase level along with a fall of Leydig cell nuclear area. Following the same treatment the significant fall of sex accessory organ weights and testicular accumulation of ascorbic acid and cholesterol were noted. On the basis of above evidence it is suggested that mitomycin C probably suppressed testicular steroidogenesis.

Andrenogonadal interactions in nicotine-induced alteration of steroidogenesis in male rat

Chronic nicotine administration in larger doses inhibits steroidogenesis in testis. This inhibition is possibly secondary to increased adrenomedullary norepinephrine activity, since the anti-steroidogenic effect of nicotine can be prevented by alpha-adrenergic blocker like phentolamine. In vitro incubation of testicular slices with nicotine failed to elicit any appreciable effect on delta 5-3 beta-hydroxysteroid dehydrogenase activity indicating lack of direct action of nicotine on testicular steroidogenesis.

In vitro studies on histochemical localization of testicular delta5-3beta-hydroxysteroid dehydrogenase activity from indomethacin pretreated rats--effect of prostaglandins and luteinizing hormone

In vitro studies on the effect of LH and prostaglandins on delta5 3beta-hydroxysteroid dehydrogenase activity using indomethacin pre-treated testis as the experimental model, revealed a greater stimulation of the enzyme activity when the incubation medium contained LH and PGE2 both at a concentration of 1 microgram/ml in comparison to the effect produced by 1 microgram LH/ml alone, but the augmentory effect of PGE2 on testicular response to LH was not evidenced as the LH: PGE2 ratio became 1 : 10. Neither PGE2 nor PGF2A produced any stimulation of the enzyme activity at concentrations of 1, 10, or 20 microgram/ml in the incubating medium. PGF2A at concentrations of 1 or 10 microgram/ml did not appear to interfere with LH action on this steroidogenic enzyme. On the contrary, prostaglandins, both PGE2 and PGF2A, at concentrations of 20 microgram/ml, antagonized LH action over testicular delta5-3beta-hydroxysteroid dehydrogenase activity. On the basis of these findings, it appears that prostaglandin E2 in some way, is necessary for manifestation of the steroidogenic action of LH in testis.

Effect of long-term treadmill running on gonadal activity in female rats

Histochemical studies of delta5-3beta-HSD and G-6-PD activities in the ovaries of female rats undergoing long term-treadmill running showed a marked reduction. This change was associated with increased concentration of total cholesterol and total ascorbic acid in the same organ. All these results suggest ovarian hypoactivity.

Pentose phosphate pathway and testicular steroidogenesis in rats following oxythiamine treatment

Suppression of delta5-3beta-hydroxy steroid dehydrogenase (delta5-3beta-OHD) and glucose-6-phosphate dehydrogenase (G-6-P-D) activities along with concomitant stimulation of succinic dehydrogenase (SDH) activity were observed in the rat testicular tissues following treatment with oxythiamine HC1, an inhibitor of pentose phosphate pathway. The same treatment also resulted in an accumulation of cholesterol and ascorbic acid in the gland associated with a decrease in the weights of seminal vesicle and prostate. The results suggest a diminution in testicular steroid biogenesis following an alteration of pentose phosphate pathway.

A method for the estimation of free and esterified cholesterol involving thin-layer chromatography

A method for the estimation of both free and bound cholesterol in serum and plasma involving thin-layer chromatography has been developed. The serum or plasma is applied as a band directly on the plate. Extraction of lipid material from this band and the chromatographic separation of the above components are carried out on the same plate. The components are extracted from the adsorbent directly with acetic acid and measured colorimetrically using iron(III) chloride-sulphuric acid reagent.

Leucyl naphthylamidase activity in pigeon and toad testes under various experimental conditions

The activity pattern and functional significance of leucyl naphthylamidase (LNase) in the pigeon testis under different hormonal and photoperiod conditions as well as in the testes of short- and long-term HCG-treated toads have been studied histochemically. In both the species, the enzyme activity was present in the maturing spermatids and those embedded in the Sertoli cell components, the mature spermatozoa released in the lumen being devoid of any LNase activity. In pigeon, the stimulation of spermatogenic process was associated with enhanced activity of the enzyme, whereas arrest of spermatogenesis showed little or no activity. In toad, short-term HCG treatment caused mild stimulation of spermiation resulting in sperm release from the Sertoli cells and this was accompanied by moderate decrease in LNase activity. The long-term HCG treatment produced an enhanced stimulation of spermiogenesis and spermiation processes resulting in almost total disappearance of LNase activity. The above observations suggest that the enzyme in the testes of both species is related to spermiogenesis and/or spermiation events of spermatogenesis.

Effect of different doses of ascorbic acid on thyroid activity in rats at different levels of dietary protein intake

Rats, which can synthesize vitamin C, react similarly to graded doses of ascorbic acid as guinea pigs. Low doses of ascorbic acid stimulate and high doses inhibit the thyroid activity of rats which are supplied with normal and high percentages of protein. The stimulatory effect of low doses of ascorbic acid on hyperactive thyroid of high protein fed animals is additive. Ascorbic acid has no significant effect on the thyroid of low protein fed animals (deficient diet supplied for 21 days). In the initial stages of protein deficiency (deficient diet supplied for 11 days) the effectiveness of vitamin C on thyroid of rats was still significant. Deiodinase enzyme activity of peripheral tissues is markedly reduced in animals supplied with 2% of protein for 21 days, but this effect is less intense in animals supplied with 2% of protein for 11 days.

Dehydrogenases in the prepubertal rat ovary: a histochemical study of delta-5-3 beta-hydroxysteroid dehydrogenase and enzymes of carbohydrate oxidation following oxythiamine treatment

A histochemical study of the NAD- and NADP-linked dehydrogenases, Δ5-3β-hydroxysteroid dehydrogenase (Δ5-3β-ODH) and glucose-6-phosphate dehydrogenase (G-6-PD), and the corresponding tetrazolium reductases in prepubertal rat ovaries following the administration of oxythiamine HCl revealed diminution in the activities of the two dehydrogenases, while the NAD- and NADP-tetrazolium reductase activities remained unchanged. The same treatment resulted in stimulation of dihydrolipoic dehydrogenase (DLDH) and succinic dehydrogenase (SDH) activities in the ovarian tissues. Supplementary histochemical demonstration of Δ5-3β-OHD activity in phosphate buffer at pH 9.0 revealed a similar localization of the enzyme as that observed at pH 7.1 and which was free of the NAD-linked diaphorase activity. A diminution of this ovarian enzyme activity at this pH was also evident, following oxythiamine treatment. The results indicate a suppression of ovarian steroidogenesis in the prepubertal rats as a result of an alteration of the pentose phosphate pathway enzyme, G-6-PD, following treatment with oxythiamine HCl.

Pentose phosphate pathway and steroidogenesis in the immature rat ovary after malonate treatment

Suppression of succinic dehydrogenase (SDH) activity resulted in stimulation of glucose-6-phosphate dehydrogenase (G-6-PD) and Δ5-3β-hydroxysteroid dehydrogenase (Δ5-3β-OHD) activities in the immature rat ovary after malonate treatment. The same treatment also produced depletion in the ovarian ascorbic acid and elevation in cholesterol concentrations, together with increase in the ovarian and uterine weight. The results indicate that stimulation of ovarian steroidogenesis, resulting from accelerated pentose phosphate pathway in combination with increased concentration of cholesterol in the gland, is possibly due to a direct effect of malonate on the immature rat ovary. The rise in ovarian and uterine weights is not due to the decreased inactivation of oestrogen in the liver, but rather to stimulation of steroid hormone synthesis in the immature ovary following malonate administration.

Carcinogens 3,4-benzpyrene and 3-methylcholanthrene: induction of mitochondrial oxidative enzymes

Sections of liver from rats injected with 3,4-benzpyrene and 3-methylcholanthrene, when incubated in mediums specific for the histochemical demonstration of mitochondrial oxidative enzymes, show greater activity of several of these enzymes than do sections from control rats. This observation was confirmed by comparison of the staining of mitochondria isolated from the control and from "induced" rats. The fact that an inhibitor of protein synthesis, actinomycin D, effectively diminished the stimulation provided evidence that the stimulation of activity is due to an increase in enzyme synthesis, generally called induction.