C6 modification of the pyridinone core of thrombin inhibitor L-374,087 as a means of enhancing its oral absorption

1 (L-374,087) is a potent, selective, efficacious, and orally bioavailable thrombin inhibitor that contains a core 3-amino-2-pyridinone moiety. Replacement of the C6 pyridinone methyl group of 1 by a propyl group gave 5 (L-375,052), which retained all the excellent properties of 1, and also yielded higher plasma levels after oral dosing in dogs and rats.     

Fractional allelic loss in gastric carcinoma correlates with growth patterns

To gain an insight into the genetic events underlying morphological phenotypes, we analysed 58 gastric carcinoma tissues for the genome-wide allelotype study using microsatellite markers. Based on a binomial distribution, loss of heterozygosity (LOH) that was significantly more frequent than expected (P<0.05) thus interpreted as nonrandom LOH selected during tumorigenesis. The overall extent of chromosomes undergoing LOH i.e. fractional allelic loss (FAL, the ratio of LOH-positive markers to the total number of informative markers) was measured in each tumor patient. Nonrandom LOH was found on 17p (48.0%), 18q (38.4%), 13q (38.1%) and 9p (36.4%). Overall, there were no significant phenotypes correlated with allelic loss on specific chromosome regions. Based on a bimodal distribution of FAL values with two peaks bordered by a mean of 0.233, tumors were classified into LOH-related (>0.233) and LOH-unrelated (<0.233) types. Among 24 patients with LOH-related tumors, increase in the infiltrative type of growth pattern was found to correspond with a significant trend of increasing FAL values. This study shows that the growth pattern of gastric carcinoma is correlated with FAL, suggesting that a malignant phenotype is influenced by LOH event.     

Mode of action of site-directed irreversible folate analogue inhibitors of thymidylate synthase

5,8-Dideazafolate analogues are tight binding but not irreversible inhibitors of thymidylate synthase (TS). However, when a chloroacetyl (ClAc) group is substituted at the N10-position of 2-desamino-2-methyl-5,8-dideazafolate (DMDDF), the resulting compound, ClAc-DMDDF, although still a reversible inhibitor (KI = 3.4 x 10(-3) M), gradually inactivates thyA-TS irreversibly at a rate of 0.37 min-1. The corresponding iodoacetyl derivative alkylated the enzyme somewhat slower (k3 = 0.15 min-1 ) than ClAc-DMDDF but was bound more tightly (KI = 1.4 x 10(-5) M), resulting in a second-order rate constant (k3/KI) of inactivation that was 100-fold greater than that of ClAc-DMDDF. A tryptic digest of the ClAc-DMDDF-inactivated enzyme yielded a peptide on HPLC, which revealed that cysteine-146, the residue at the active site that is intimately involved in the catalytic process, had reacted with ClAc-DMDDF to form a covalent bond. This derivative was confirmed indirectly by Edman analysis and more directly by mass spectrometry. Deoxyuridine 5'-monophosphate, a substrate in the catalytic reaction, protected against inactivation. Similar to previously described Lactobacillus casei TS inhibition studies with sulfhydryl reagents [Galivan, J., Noonan, J., and Maley, F. (1977) Arch. Biochem. Biophys. 184, 336-345], the kinetics of inhibition suggested that complete inhibition occurs on reaction of only one of the two active site cysteines, although sequence and amino acid analysis revealed that iodoacetate and ClAc-DMDDF had reacted with both active site cysteines. These studies demonstrate that a sulfhydryl reactive compound that is directed to the folate binding site of TS may diffuse to the active site cysteine, and form a covalent bond with this residue. How this inhibition comes about is suggested in a stereoscopic view of the ligand when modeled to the known crystal structure of Escherichia coli TS.     

Glucose intolerance and associated factors in the Fergana Valley, Uzbekistan

Prevalence of glucose intolerance and other noncommunicable diseases has been examined in subjects aged 35 years and over in semirural and urban communities in the Fergana Valley in the eastern part of Uzbekistan, Central Asia. Diabetes and impaired glucose tolerance (IGT) were diagnosed according to the recommendations of the latest WHO Study Group on diabetes. Crude prevalence of diabetes was 9% and 5%, respectively, in semirural men and women, 13% and 9% in urban men and women. Crude prevalence of impaired glucose tolerance (IGT) was 6% and 9%, respectively, in semirural men and women, 9% and 8% in urban men and women. After adjustment for non-response, prevalence of diabetes was 5% and 4%, respectively, in semirural men and women and 8% in both urban men and women. Adjusted prevalence of IGT was 4% and 8%, respectively, in semirural men and women, 5% and 6% in urban men and women. The majority of subjects with a prior diagnosis of diabetes were being treated with oral hypoglycaemic agents. Almost one-half of subjects in both communities had body mass index of 25 kg m(-2) or greater. Central obesity (waist-hip ratio 0.95 or greater for men, 0.85 or greater for women) was observed in over one-quarter of subjects in both communities. Clinical hypertension was not frequent by international standards (9% in semirural subjects and 13% in urban subjects) but a number of subjects who were clinically normotensive claimed to be taking antihypertensive medication. It is concluded that glucose intolerance and central obesity are common in this region of Uzbekistan, about which there was previously little information.     

The role of laparoscopy in the management of pelvic pain in women of reproductive age

OBJECTIVE: To review the diagnostic and therapeutic roles of laparoscopy in women of reproductive age with acute and chronic pelvic pain. DATA IDENTIFICATION: Studies relating to the use of laparoscopy in women with acute and chronic pelvic pain were identified through the literature and MEDLINE searches. CONCLUSION(S): Laparoscopy has an important place in the management of conditions that cause acute pelvic pain in women of reproductive age, including ectopic pregnancy, pelvic inflammatory disease, tubo-ovarian abscess, and adnexal torsion. The procedure frequently facilitates the diagnosis and provides the necessary access for surgical treatment. Prompt diagnosis and effective management prevent complications and help preserve fertility. The role of laparoscopy in women with chronic pelvic pain is more controversial and limited, but abnormal laparoscopic findings are detected in approximately 60% of those who have undergone a multidisciplinary investigation and received a tentative clinical diagnosis. The access provided by laparoscopy permits the effective surgical treatment of many of the conditions encountered, including endometriosis, pelvic adhesions, ovarian lesions, and symptomatic uterine retroversion.     

The Bacillus thuringiensis vegetative insecticidal protein Vip3A lyses midgut epithelium cells of susceptible insects

The Vip3A protein is a member of a newly discovered class of vegetative insecticidal proteins with activity against a broad spectrum of lepidopteran insects. Histopathological observations indicate that Vip3A ingestion by susceptible insects such as the black cutworm (Agrotis ipsilon) and fall armyworm (Spodoptera frugiperda) causes gut paralysis at concentrations as low as 4 ng/cm2 of diet and complete lysis of gut epithelium cells resulting in larval death at concentrations above 40 ng/cm2. The European corn borer (Ostrinia nubilalis), a nonsusceptible insect, does not develop any pathology upon ingesting Vip3A. While proteolytic processing of the Vip3A protein by midgut fluids obtained from susceptible and nonsusceptible insects is comparable, in vivo immunolocalization studies show that Vip3a binding is restricted to gut cells of susceptible insects. Therefore, the insect host range for Vip3A seems to be determined by its ability to bind gut cells. These results indicate that midgut epithelium cells of susceptible insects are the primary target for the Vip3A insecticidal protein and that their subsequent lysis is the primary mechanism of lethality. Disruption of gut cells appears to be the strategy adopted by the most effective insecticidal proteins.