alpha-Hydroxy phosphinyl-based inhibitors of human renin

The design and application of alpha-hydroxy phosphonates, a new class of transition state analogs, toward the discovery of novel and potent inhibitors of the aspartyl protease renin is described. Tripeptidic alpha-hydroxy diethyl phosphonate 3, the first example in this series, was found to be a good inhibitor of human renin (IC50 = 29 nM), and preliminary studies led to the choice of alpha-hydroxy dimethyl phosphonate 15 (IC50 = 16 nM) as a base-line compound for further structure-activity relationship study. Corresponding phosphinate (28-30) and phosphine oxide (23 and 24) analogs of 15 were prepared to assess the steric and electronic requirements around the phosphorus center. Evaluation of these analogs suggested that the presence of at least one alkoxy group on phosphorus was a critical requirement for good activity. Inhibitors with leucine at P2 possessed better in vitro activity than the corresponding P2 histidine analogs (15, IC50 = 16 nM vs 37, IC50 = 220 nM; 33, IC50 = 8.5 nM vs 40, IC50 = 41 nM). Compound 34 (IC50 = 31 nM), the P3 aminocaproic analog of 15, showed complete and long-lasting inhibition of plasma renin activity while eliciting a 10-15 mmHg drop in mean arterial pressure when administered intravenously at 1 mumol/kg in conscious, sodium-depleted, cynomolgus monkeys. In summary, the alpha-hydroxy phosphonates represent a promising and structurally novel class of transition state analog inhibitors of human renin.

Repeat treatment of obese mice with BRL 49653, a new potent insulin sensitizer, enhances insulin action in white adipocytes. Association with increased insulin binding and cell-surface GLUT4 as measured by photoaffinity labeling

(+/-)-5-([4-[2-Methyl-2(pyridylamino)ethoxy]phenyl]methyl) 2,4-thiazolidinedione (BRL 49653) is a new potent antidiabetic agent that improves insulin sensitivity in animal models of NIDDM. In C57BL/6 obese (ob/ob) mice, BRL 49653, included in the diet for 8 days, improved glucose tolerance. The half-maximal effective dose was 3 mumol/kg diet, which is equivalent to approximately 0.1 mg/kg body wt. Improvements in glucose tolerance were accompanied by significant reductions in circulating triacylglycerol, nonesterified fatty acids, and insulin. The insulin receptor number of epididymal white adipocytes prepared from obese mice treated with BRL 49653 (30 mumol/kg diet) for 14 days was increased twofold. The affinity of the receptor for insulin was unchanged. In the absence of added insulin, the rates of glucose transport in adipocytes from untreated and BRL 49653-treated obese mice were similar. Insulin (73 nmol/l) produced only a 1.5-fold increase in glucose transport in adipocytes from control obese mice, whereas after BRL 49653 treatment, insulin stimulated glucose transport 2.8-fold. BRL 49653 did not alter the sensitivity of glucose transport to insulin. The increase in insulin responsiveness was accompanied by a 2.5-fold increase in the total tissue content of the glucose transporter GLUT4. Glucose transport in adipocytes from lean littermates was not altered by BRL 49653. To establish the contribution of changes in glucose transporter trafficking to the BRL 49653-mediated increase in insulin action, the cell-impermeant bis-mannose photolabel 2-N-[4-(1-azi-2,2,2-trifluoroethyl)benzoyl]-1,3-bis-(D-mannos++ +-4-yloxy) -2-[2-3H]-propylamine was used to measure adipocyte cell-surface-associated glucose transporters.(ABSTRACT TRUNCATED AT 250 WORDS)

Patella of selected bats: patterns of occurrence or absence and associated modifications of the quadriceps femoris tendon

BACKGROUND

Having observed the apparent absence of a bony patella in a Madagascar flying fox (Pteropus sp.), other species from the two suborders of bats (Megachiroptera and Microchiroptera) were examined to determine the presence or absence of a bony patella and the distribution of this feature among bats.

METHODS

Gross, radiographic, and histologic examination of seven megachiropteran species representing four genera, as well as six microchiropteran species representing six genera, was performed.

RESULTS

A bony patella was observed in all six microchiropteran and in three megachiropteran species. The tendon of the quadriceps femoris muscle in Microchiropteran species was composed mainly of dense regular connective tissue. The quadriceps tendon in Megachiropteran species with a patella contained an abundance of fibrocartilage and hyaline cartilage, unlike the quadriceps femoris tendon of the Microchiroptera or a laboratory mouse examined for comparison.

CONCLUSIONS

Four species of the megachiropteran genus Pteropus lacking a bony patella displayed a similar occurrence and distribution of fibrocartilage and hyaline cartilage within the quadriceps tendon as seen in the other bats. In reference to this singular feature, Pteropus is unique among the representatives of megachiropteran and microchiropteran genera examined here.

Isolation and mapping of a gene encoding a novel human ADP-ribosylation factor on chromosome 17q12-q21

A gene encoding a low-molecular-weight GTP-binding protein was isolated from a retinal cDNA library and mapped to human chromosome 17q12-q21. Comparison of the predicted protein with the protein databases revealed striking homology to the family of ADP-ribosylation factors (ARFs), which are thought to be involved in membrane trafficking and protein secretion. The greatest homology observed was with the rat ARF-like 4 protein (ARL4), with which it shared 58% identity, while the more highly conserved human ARF1 and ARF3 proteins each shared 46% identity. Inspection of the predicted new protein showed that it contained each of the six conserved motifs that are required for guanine nucleotide binding and hydrolysis, and thus it is probably a novel ARF isoform. We have designated the new protein and its corresponding gene ARF4L.

Detection of eight BRCA1 mutations in 10 breast/ovarian cancer families, including 1 family with male breast cancer

Genetic epidemiological evidence suggests that mutations in BRCA1 may be responsible for approximately one half of early onset familial breast cancer and the majority of familial breast/ovarian cancer. The recent cloning of BRCA1 allows for the direct detection of mutations, but the feasibility of presymptomatic screening for cancer susceptibility is unknown. We analyzed genomic DNA from one affected individual from each of 24 families with at least three cases of ovarian or breast cancer, using SSCP assays. Variant SSCP bands were subcloned and sequenced. Allele-specific oligonucleotide hybridization was used to verify sequence changes and to screen DNA from control individuals. Six frameshift and two missense mutations were detected in 10 different families. A frameshift mutation was detected in a male proband affected with both breast and prostate cancer. A 40-bp deletion was detected in a patient who developed intra-abdominal carcinomatosis 1 year after prophylactic oophorectomy. Mutations were detected throughout the gene, and only one was detected in more than a single family. These results provide further evidence that inherited breast and ovarian cancer can occur as a consequence of a wide array of BRCA1 mutations. These results suggests that development of a screening test for BRCA1 mutations will be technically challenging. The finding of a mutation in a family with male breast cancer, not previously thought to be related to BRCA1, also illustrates the potential difficulties of genetic counseling for individuals known to carry mutations.

A gene (DLG2) located at 17q12-q21 encodes a new homologue of the Drosophila tumor suppressor dIg-A

We have isolated a novel cDNA that maps distal to BRCA1 at 17q12-q21. The total sequence predicts a protein of 576 amino acids with three conserved regions: a 90-amino-acid repeat domain, a SH3 (src homology region 3) motif, and a guanylate kinase domain. These conserved regions are shared among members of the discs-large family of proteins that include human p55, a membrane protein expressed in erythrocytes, rat PSD-95/SAP90, a synapse protein expressed in brain, Drosophila dIg-A, a septate junction protein expressed in various epithelia, and human and mouse ZO-1 and canine ZO-2, two tight junction proteins. dIg-A has been shown to act as a tumor suppressor, and the other members may all be involved in signal transduction through specialized membrane domains with highly organized cytoskeletons and thus are potential tumor suppressors. Since allelic loss has been reported in the 17q12-q21 region in breast and ovarian cancer and it appears that BRCA1 is not the target of the losses, we looked for somatic alterations in DLG2 in sporadic breast tumors. No evidence for mutation was found, making it unlikely that DLG2 is involved in sporadic breast cancer.

The University of Minnesota Cancer Prevention Research Unit vegetable and fruit classification scheme (United States)

High vegetable and fruit (V&F) intake has been associated with a lower risk of many cancers. However, the specific V&F, the active compounds present in V&F, and the dose at which they confer protection are unknown. Standard methods for assessing, classifying, and quantifying V&F exposures in epidemiologic studies have not been established. Differences among studies occur due to inherent differences among V&F, and across dietary assessment methods, study populations, etiologic hypotheses, and analytic methods. The V&F classification scheme presented here characterizes and quantifies V&F consumption for elucidating risk relationships, identifying chemopreventive compounds present in V&F, and facilitating identification of potential biomarkers of V&F intake. Broad criteria define which plant foods count as V&F. Formation of food groups is based on proposed biological mechanisms of action. Five main groups are included: Total V&F; Total Vegetables; Total Fruits; and two groups orthogonal to these -- the Botanical and Phytochemical groups. Subgroups are specified within each main group. V&F exposure is quantified as the absolute amount consumed (weight) or as the number of household servings. This classification scheme has public health applications and may be used to examine associations with chronic diseases other than cancer.

An in-vitro biomechanical comparison of the Orosco and AO locking plates for anterior cervical spine fixation

The Orosco anterior cervical spine plate (H-plate) and the Morscher AO cervical locking plate (CSLP) were studied to determine their comparative in vitro mechanical properties in flexion. Human cadaver cervical spines were tested nondestructively in flexion as intact, destabilized, and stabilized specimens with both implants. Stabilized specimens were also subjected to a large angular displacement in an attempt to induce implant failure. Differences between intact, destabilized, and stabilized specimens were significant for both the CSLP and H-plate groups in flexion testing (p < 0.05). Large angular displacement testing resulted in plate/screw displacement with the H-plate but not with the CSLP. Small angular displacements in flexion was tolerated well by both implants, but only the CSLP maintained stability with large angular displacements.

Commonly asked questions about thyroid function

Thyroid function abnormalities in asymptomatic outpatients are common. When a patient is found to have an abnormality in thyrotropin (thyroid-stimulating hormone) or free or total thyroxine (T4), a review of the patient's medications and a careful neck examination will usually provide the explanation. Further diagnostic laboratory studies should include additional tests of T4 or thyrotropin. Determining the presence of antimicrosomal antibodies is useful for further assessment of "subclinical" hypothyroidism, and measures of protein binding (T4-binding capacity or T4-binding protein electrophoresis) help confirm a suspected congenital or acquired abnormality of T4 binding. Recognition of euthyroid hypothyroxinemia and hyperthyroxinemia is important in order to avoid intervention with inappropriate treatment. Management of subclinical hypothyroidism and hyperthyroidism necessitates clinical judgment about the patient's symptom profile and risks for long-standing or progressive thyroid dysfunction.

Prostate cancer in Florida: knowledge, attitudes, practices, and beliefs

In Florida, prostate cancer continues to be an increasing public health problem, especially among the elderly and medically underserved. Bilingual, random-digit-dialed telephone interviews were conducted with 897 men who were 65 years and older in Dade and Hillsborough counties, with the sample stratified along racial and ethnic lines. The purpose of the survey was to obtain information regarding knowledge, attitudes, practices, and beliefs about prostate cancer, its prevention, and early detection. More than 60% of the 897 respondents believed that a person with prostate cancer had an 80% or greater chance for cure, yet only 67% reported ever having a digital rectal examination. Black (35.7%) and Hispanic respondents (42.5%) were twice as likely to have never had a digital rectal examination than were their white counterparts (19.8%). When asked why they had never had this examination or had not had one in the past 2 years, 38.5% replied that it was "not needed/not necessary" and 27.6% replied they "had not had any problems." When asked their sources for answers to health-related questions, physicians ranked first whereas family and friends ranked near the bottom on a list of some 11 sources. Clearly, efforts need to be increased to identify, reduce, and/or eliminate potential barriers to use of early-detection programs.

Long-term survival in the Wolf-Hirschhorn (4p-) syndrome

The clinical features of Wolf-Hirschhorn syndrome are described in a 29-year-old woman who shows severe retardation of growth and development. It is important for health care professionals involved with families in which this condition is present to realize that long-term survival may occur.

A quick screening test of competency to stand trial for defendants with mental retardation

19 terms and concepts from evaluations of competency to stand trial of 55 defendants with mental retardation were rated to examine whether a quick screening test could be devised that would differentiate those who were judged competent or not competent. A multiple regression and discriminant analysis gave four items that yielded maximum predictability (R = .84): court strategy, plead, testify, and jury. Guilty, trial, and prosecutor were also significantly more difficult for those who were not competent than those who were.

An evaluation of genetic heterogeneity in 145 breast-ovarian cancer families. Breast Cancer Linkage Consortium

The breast-ovary cancer-family syndrome is a dominant predisposition to cancer of the breast and ovaries which has been mapped to chromosome region 17q12-q21. The majority, but not all, of breast-ovary cancer families show linkage to this susceptibility locus, designated BRCA1. We report here the results of a linkage analysis of 145 families with both breast and ovarian cancer. These families contain either a total of three or more cases of early-onset (before age 60 years) breast cancer or ovarian cancer. All families contained at least one case of ovarian cancer. Overall, an estimated 76% of the 145 families are linked to the BRCA1 locus. None of the 13 families with cases of male breast cancer appear to be linked, but it is estimated that 92% (95% confidence interval 76%-100%) of families with no male breast cancer and with two or more ovarian cancers are linked to BRCA1. These data suggest that the breast-ovarian cancer-family syndrome is genetically heterogeneous. However, the large majority of families with early-onset breast cancer and with two or more cases of ovarian cancer are likely to be due to BRCA1 mutations.

Furosemide pharmacokinetics following intratracheal instillation in the guinea pig

Inhaled furosemide has been shown to attenuate bronchospasm in asthmatics and to increase lung compliance in infants with bronchopulmonary dysplasia (BPD). The reports involving BPD used a dose of 1 mg/kg and some have failed to show an effect with that dose. We determined the pharmacokinetics of furosemide administered directly to the airway in 7 young adult male guinea pigs who received intravenous and intratracheal doses of furosemide. Each animal received a 3 mg/kg i.v. bolus, 1, 3 and 6 mg/kg i.t. in 2 ml/kg normal saline and 3 mg/kg i.t. in 2 ml/kg bovine extract surfactant. Blood was sampled multiple times after each dose. The mean fraction of the intratracheal dose absorbed was 0.50-0.60 for all doses. Surfactant delayed the absorption of furosemide but did not alter the fraction absorbed.

Ultrasound findings in renal parenchymal disease: comparison with histological appearances

Ultrasound examination was carried out in 55 patients undergoing renal biopsy for suspected renal parenchymal disease. Analysis of sonographic and histological findings showed statistically significant positive correlations between renal size and the extent of glomerular hyper-cellularity and crescent formation and between cortical echogenicity and severity of glomerular sclerosis, crescent formation, interstitial inflammatory cell infiltration, tubular atrophy and interstitial fibrosis. Positive correlation was also observed between prominence of the medullary pyramids and glomerular sclerosis. The most marked sonographic abnormalities were seen in proliferative (including crescentic) glomerulonephritis, diabetic glomerulosclerosis and tubulo-interstitial nephritis. IgA, membranous and minimal change nephropathy were less likely to be associated with sonographic abnormalities. We conclude that certain sonographic appearances in renal parenchymal disease reflect the presence and severity of light microscopical abnormalities but, although ultrasound assessment provides a high positive predictive value for renal parenchymal disease, specific conditions cannot be distinguished.

The complete cDNA derived sequence of the rat prolyl 4-hydroxylase alpha subunit

A rat cDNA encoding the prolyl 4-hydroxylase alpha subunit (P4H alpha) was isolated and sequenced. The primary aa sequence deduced from the nucleotide sequence reveals a 534-aa protein that shows extensive aa identity with the human (88%) and chick (77%) P4H alpha.

[[omega-(Heterocyclylamino)alkoxy]benzyl]-2,4-thiazolidinediones as potent antihyperglycemic agents

A series of [(ureidoethoxy)benzyl]-2,4-thiazolidinediones and [[(heterocyclylamino)alkoxy]-benzyl]-2,4-thiazolidinediones was synthesized from the corresponding aldehydes. Compounds from the urea series, exemplified by 16, showed antihyperglycemic potency comparable with known agents of the type such as pioglitazone and troglitazone (CS-045). The benzoxazole 49, a cyclic analogue of 16, was a very potent enhancer of insulin sensitivity, and by modification of the aromatic heterocycle, an aminopyridine, 37, was identified as a lead compound from SAR studies. Evaluation of antihyperglycemic activity together with effects on blood hemoglobin content, to determine the therapeutic index, was performed in 8-day repeat administration studies in genetically obese C57 Bl/6 ob/ob mice. From these studies, BRL 49653 (37) has been selected, on the basis of antihyperglycemic potency combined with enhanced selectivity against reductions in blood hemoglobin content, for further evaluation.

Elevated serum nickel concentration in psoriasis vulgaris

BACKGROUND

Psoriasis vulgaris is a common skin disease afflicting 1-3% of the American population. Its pathogenesis remains unknown despite concerted research efforts. Our purpose was to study baseline serum nickel concentrations in psoriasis vulgaris subjects and in healthy control subjects.

METHODS

Sixteen psoriasis vulgaris subjects with active disease (in 14 of moderate to marked severity), and 11 age- and sex-matched healthy control subjects were studied. Serum nickel determinations were performed using electrothermal atomic absorption spectrophotometry (ETAAS).

RESULTS

Despite the relatively small sample size, significant elevation of mean serum nickel concentration was found in the psoriasis group compared to the control group (P = 0.019).

CONCLUSIONS

Recognition of abnormal nickel homeostasis could point the way to greater understanding of the primary biochemical defect in the psoriatic process. Alternatively, this finding may mark an association without pathogenic significance. Further investigation is needed.

Protein expression using cotranslational fusion and cleavage of ubiquitin. Mutagenesis of the glutathione-binding site of human Pi class glutathione S-transferase

Expression of cloned genes in prokaryotes such as Escherichia coli is a widely used technique in both basic research and biotechnology. Despite the availability of several E. coli expression vector systems, adequate levels of expression may not be achieved. Expressing proteins as fusions to the highly conserved eukaryotic protein ubiquitin has been reported by several investigators to enhance protein yield in both bacterial and eukaryotic systems. We have modified this technique by the co-expression in E. coli of a ubiquitin-fusion protein and the Saccharomyces cerevisiae ubiquitin-specific protease Ubp2. This allows the co-translational cleavage of engineered ubiquitin-fusion proteins expressed in E. coli. This system was used to express a human Pi class glutathione S-transferase (GST) GSTP1 as well as two mutant GSTP1 derivatives, Trp39-->Cys and Gln52-->Glu. The yield of these enzymes was improved 40-fold by using the ubiquitin-fusion/co-translational cleavage technique, and no uncleaved product was detected. The Trp39-->Cys mutant was totally devoid of GST activity, while the activity of the Gln52-->Glu mutant was reduced to 6% of wild-type GSTP1-1. As both of the mutated residues map within the glutathione-binding site, the reduced GST activity is consistent with a marked reduction in glutathione binding ability.

The beta-adrenoceptor selectivity profile of BRL 37344 in the pithed rat

1. Rats were pithed in order to disrupt baroreflex pathways. Heart rate was used as a measure of beta 1-adrenoceptor activity, blood pressure as a measure of beta 2-adrenoceptor activity and oxygen consumption and brown adipose tissue temperature as measures of beta 3-adrenoceptor activity. 2. The effects of the selective beta 3-adrenoceptor agonist BRL 37344 were compared with those of isoprenaline, a non-selective beta-adrenoceptor agonist, and denopamine and salbutamol, which are respectively beta 1 and beta 2-adrenoceptor agonists. 3. Denopamine was 10-fold more potent on heart rate than blood pressure, whilst salbutamol was 18-fold more potent on blood pressure than heart rate. These findings confirm that in this preparation increases in heart rate are predominantly beta 1 adrenoceptor-mediated, whilst blood pressure is beta 2-adrenoceptor-mediated. Further confirmation is provided by the blockade with atenolol, of the chronotropic effect, but not the blood pressure effect, of isoprenaline. 4. BRL 37344 was the most potent beta-adrenoceptor agonist on both oxygen consumption and brown adipose tissue temperature, revealing the beta 3-nature of these responses. Dose-response curves for oxygen consumption and brown adipose tissue temperature were identical, whichever of the beta-adrenoceptor agonists was used. Both systems may be considered equally effective as indicators of beta 3-adrenoceptor agonist activity.

Severe microphthalmia, diaphragmatic hernia and Fallot's tetralogy associated with a chromosome 1;15 translocation

A 9-year-old boy with multiple abnormalities including severe bilateral microphthalmia, diaphragmatic hernia and Fallot's tetralogy is presented. He has also been shown to have an apparently balanced de novo reciprocal translocation, 46,XY,t(1;15)(q41;q21.2), which suggests that one of those breakpoints may be the locus for a gene which is important in morphogenesis.