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Biomedical subjects

A Hayes

Publications and source records attributed to A Hayes.

At least 127 records · Page 7Linked to original sources
PubMed1986

Lethal osteogenesis imperfecta with amniotic band lesions: collagen studies.

An infant was born with osteogenesis imperfecta (OI) and died after 7 days. In addition, there were amniotic constriction bands and amputations of several digits of the upper and lower limbs. The radiologic picture was suggestive of type III OI. Histomorphometric analysis of the bone showed a trabecular bone volume of 15.1% compared to 26.9% for age-matched controls. This was due to a decreased apposition of matrix by the osteoblasts. Because abnormal collagen synthesis has been suggested as the underlying defect in most forms of OI, collagen studies were undertaken using intact tissues. Bone and skin collagen solubilities were strikingly reduced. Shortened type I collagen molecules, representing 25% of the total type I collagen, were produced by pepsin digestion of the demineralized bone matrix. The molecular weight of the shortened collagen, was 10 kd lower than normal for both the alpha 1 and alpha 2 chains as determined by gel electrophoresis. The bone acetic acid-soluble collagen showed few shortened alpha-chains. Twenty-five percent of the acid-soluble bone collagen was cleaved into shortened molecules by a pepsin digestion. The shortened alpha 1 chain was purified by high-performance liquid chromatography (HPLC) and digested with CNBr. The analysis of the resulting fragments by HPLC and by gel electrophoresis unequivocally demonstrated that the shortened alpha 1 chain was derived from the alpha 1(I) chains and that the pepsin sensitivity extends from the amino terminal end of the chain to the alpha 1(I) CB5 peptide, approximately 120 residues inside the triple helix. These studies show a distinct structural abnormality of type I collagen in the bone matrix of this patient resulting in an increased sensitivity of the collagen to general enzymatic proteolysis. The importance of correlating clinical and biochemical information in OI is emphasized; classification and genetic counseling based only on clinical observations are inaccurate.

Amniotic Band Syndrome↗
PubMed1986

Molecular markers of hemostatic activation in atherosclerosis: a new concept in diagnostic profiling of endogenous pathophysiologic transition.

Molecular markers of hemostatic activation provide a reliable measure of the endogenous pathophysiologic state in atherosclerosis. Measurement of these markers before and after exercise provides a diagnostic probe for cellular-vascular interactions in patients with atherosclerosis. Molecular markers may possibly identify very early stages of atherosclerosis due to their inherent sensitivity. A high-risk cardiovascular population can be easily recognized by profiling molecular markers of hemostatic activation. Newly developed immunoassays can be used to quantitate these markers in routine laboratories. Additional clinical studies are needed to establish the diagnostic role of these molecular markers in patients with atherosclerosis and related disorders.

6-Ketoprostaglandin F1 alpha↗
PubMed1986

Maternal control of co-vocalization and inter-speaker silences in mother-infant vocal engagements.

Co-vocalizations and inter-speaker silences were used to investigate the vocal engagements of six mother-infant dyads. Observed records of vocal behaviours were compared with records in which the vocal behaviours were randomized. The results indicated that there were significantly fewer co-vocalizations in observed than in randomized records; that the durations of inter-speaker silences following infant vocalization were significantly shorter in observed than in randomized records; and that the durations of inter-speaker silences following maternal vocalization were significantly longer in observed than in randomized records. These findings were interpreted as being consistent with the view that mothers attempt to engage their infants in turn-taking encounters, and that descriptions of such engagements in terms of conversational metaphors may be misleading in this regard.

Female↗
PubMed1985

Profile of activity of kappa receptor agonists in the rabbit vas deferens.

The purpose of this study was to investigate further the kappa opioid receptor selectivity of the field-stimulated isolated rabbit vas deferens preparation and to study the profile of a series of kappa agonists in this tissue. Agonists acting at mu, delta and sigma receptors were without detectable effect in the rabbit vas deferens. But a number of kappa agonists, including bremazocine, tifluadom, ethylketocyclazocine, ketocyclazocine, U-50,488 and Win 42,610 all depressed contractions, producing parallel dose-response curves. Mr 2034 generally produced a shallower dose-response curve and achieved a lower maximum effect, thus acting like a partial agonist. The effect of ethylketocyclazocine was not reduced by the irreversible mu antagonist, beta-funaltrexamine, confirming that it is not acting via mu receptors. Another group of drugs, including nalorphine, butorphanol and proxorphan, which produce an agonist action via kappa receptors in the guinea-pig ileum and mouse vas deferens, were antagonists in the rabbit vas deferens, suggesting that this tissue will only respond to high efficacy kappa agonists.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1985

The effect of Mendelian disease on human health. II: Response to treatment.

We describe an attempt to measure efficacy of treatment in the Mendelian diseases of man. We used the McKusick Catalogs to identify 351 single gene diseases. We scored the impact of each disease in seven phenotypic categories: lifespan, reproductive capability, somatic growth, intellectual development, learning ability, capacity to work, and cosmetic effect. We then scored the success of treatment in ameliorating each of these component manifestations separately and together. The response to treatment was slight in the whole sample (n = 351): lifespan was increased in 15%, reproductive capability in 11%, and social adaptation in 6%. We observed that the mutant gene product was known in only 15% of the conditions comprising our sample. Since the mutant polypeptide is known in most inborn errors of metabolism, the diseases of this type (n = 65) in our sample of Mendelian traits were studied separately. In each of the seven categories of phenotypic impact, only a few of the hereditary metabolic diseases responded in any degree to specific treatment: the treatment gave complete relief in 12%, there was a partial response in 40%, and none in the remaining 48%. These findings have implications for prognosis, genetic counseling, and medical care of patients with Mendelian disease.

Adaptation, Psychological↗
PubMed1985

The Okihiro syndrome of Duane anomaly, radial ray abnormalities, and deafness.

We report on a child with Duane anomaly, deafness, cervical spine, and radial ray abnormalities. A sister of the proposita had hemifacial microsomia, cervical abnormalities, and hypoplasia of the thenar eminence. Four relatives had hypoplasia of the thenar eminence. A fifth had preaxial polydactyly. Duane anomaly was present in two sixth-degree relatives. This appears to be an autosomal dominant trait. Singly or in combination the abnormalities seen in this family have all been described in association with Duane anomaly. Their occurrence in the same family suggests that they are not independent entities but represent pleiotropic effects of the same gene.

Abnormalities, Multiple↗
PubMed1985

Evaluation of effects of levamisole and surgery on canine mammary cancer.

Three hundred and forty-five dogs with mammary tumors were initially evaluated for study. One hundred and forty-four dogs with untreated malignant mammary tumors (136 adenocarcinomas, 5 malignant mixed, 3 sarcomas) were selected for study. All dogs were clinically staged and stratified on the basis of tumor volume and body weight. Dogs were randomized to either a radical mastectomy or simple mastectomy group, and then further randomized to a levamisole or placebo group. There was no significant difference in either survival time or cancer-free survival time between the surgery groups or between the levamisole and placebo groups. The most significant prognostic factor was tumor volume; dogs with tumors less than 41 cc had significantly enhanced survival time (p = 0.0007) and cancer-free survival time (p = 0.0005).

Animals↗
PubMed1984

Effect of extraction time on ability of calmodulin to activate 30S and 14S dynein ATPases.

Cilia from the protozoan Tetrahymena pyriformis were demembranated and then extracted for 5 min with a buffer containing 0.5 M NaCl. The briefly extracted axonemal pellet was then reextracted for about 20 hr. The soluble material obtained from each extraction was resolved into 14S and 30S dynein ATPases by sedimentation on sucrose density gradients and tested for sensitivity to added calmodulin. The 14S dynein obtained by a 5-min extraction was generally insensitive to added calmodulin, whereas that obtained by 20-hr extraction of the 5-min extracted axonemes was activated by calmodulin, the activation being much larger in the "light" 14S fractions than in the "heavy" fractions. The 30S dynein ATPase obtained by a 5-min extraction was generally activated over 1.6-fold by added calmodulin, whereas that obtained by the subsequent long extraction was usually activated only 1.3-fold. After further purification of the 5-min extracted 30S dynein and of the 5-min to 20-hr-extracted 14S dynein on DEAE-Sephacel, these dyneins retained much of their calmodulin activatability. The ATPase activity of both 14S and 30S dyneins was inhibited more strongly by erythro-9-[3-(2-hydroxynonyl)] adenine and by vanadate in the presence of added calmodulin than in its absence. These data suggest that the only ATPase activity present in the fractions studied is that of the dyneins and demonstrate that both the 14S and 30S dynein ATPases may be obtained in forms that are activated by added calmodulin as well as in forms that are insensitive to added calmodulin.

Adenine↗
PubMed1984

Specific anion effects on ATPase activity, calmodulin sensitivity, and solubilization of dynein ATPases.

The basal ATPase activity of 30S dynein, whether obtained by extraction of ciliary axonemes with a high (0.5 M NaCl) or low (1 mM Tris-0.1 mM EDTA) ionic strength buffer is increased by NaCl, NaNO3, and Na acetate, with NaNO3 causing the largest increase. The calmodulin-activated ATPase activity of 30S dynein is also increased by addition of NaCl, NaNO3, or Na acetate, but the effects are less pronounced than on basal activity, so that the calmodulin activation ratio (CAR) decreases to 1.0 as salt concentration increases to 0.2 M. These salts also reduce the CAR of 14S dynein ATPase to 1.0 but by strongly inhibiting the calmodulin-activated ATPase activity and only slightly inhibiting the basal activity. Sodium fluoride differs both quantitatively and qualitatively from the other three salts studied. It inhibits the ATPase activity of both 14S and 30S dyneins at concentrations below 5 mM and, by a stronger inhibition of the calmodulin-activated ATPase activities, reduces the CAR to 1.0. Na acetate does not inhibit axonemal ATPase, nor does it interfere with the drop in turbidity caused by ATP and extracts very little protein from the axonemes. NaCl and, especially, NaNO3, cause a slow decrease in A350 of an axonemal suspension and an inhibition of the turbidity response to ATP. NaF, at concentrations comparable to those that inhibit the ATPase activities of the solubilized dyneins, also inhibits axonemal ATPase activity and the turbidity response. Pretreatment of demembranated axonemes with a buffer containing 0.25 M sodium acetate for 5 min followed by extraction for 5 min with a buffer containing 0.5 M NaCl and resolution of the extracted dynein on a sucrose density gradient generally yields a 30S dynein that is activated by calmodulin in a heterogeneous manner, ie, the "light" 30S dynein ATPase fractions are more activated than the "heavy" 30S dynein fractions. These results demonstrate specific anion effects on the basal and calmodulin-activated dynein ATPase activities, on the extractability of proteins from the axoneme, and on the turbidity response of demembranated axonemes to ATP. They also provide a method that frequently yields 30S dynein fractions with ATPase activities that are activated over twofold by added calmodulin.

Acetates↗
PubMed1982

Heterogeneity of 14S and 30S dynein ATPase activities with respect to activation by calmodulin.

Demembranated cilia of Tetrahymena pyriformis were extracted with KCl or Tris-EDTA and the crude dyneins from each resolved by sucrose density gradient sedimentation into 14S-K, 30S-K, 14S-E and 30S-E dyneins, respectively. The calmodulin activation ratio (ATPase activity in presence of added calmodulin/ATPase activity in absence of added calmodulin) did not vary across the 30S dynein fractions regardless of the method of extraction nor did it vary across the 14S-E region. However, in going from the "heavy" fractions to the "light" fractions of the 14S-K region, it increased markedly. The concentration of calmodulin required for half-maximal activation did not differ appreciably in the "light" versus the "heavy" fractions of the 14S-K region, suggesting that the affinity for calmodulin does not vary in these fractions. SDS-polyacrylamide gel electrophoresis studies showed the presence of several polypeptides that varied in a systematic fashion across the 14S-K region and hence may be involved in regulating the sensitivity of 14S-K dynein ATPase activity to added calmodulin.

Adenosine Triphosphatases↗