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Biomedical subjects

A Goldman

Publications and source records attributed to A Goldman.

At least 145 records · Page 8Linked to original sources
PubMed1990

Myo-inositol and prostaglandins reverse the glucose inhibition of neural tube fusion in cultured mouse embryos.

Neural tube defects in infants of diabetic mothers constitute an important and frequent cause of neonatal mortality/morbidity and long-term chronic handicaps. The mechanism by which normal neural tube fusion occurs is not known. The failure of rostral neural tube fusion seen in mouse embryos incubated in the presence of excess-D-glucose can be significantly prevented by the supplementation of myo-inositol to the culture medium. This protective effect of myo-inositol is reversed by indomethacin, an inhibitor of arachidonic acid metabolism leading to prostaglandin synthesis. Prostaglandin E2 added to the culture medium completely protects against the glucose-induced neural tube defect. These data suggest that the failure of neural tube fusion seen in diabetic embryopathy is mediated through a mechanism involving abnormalities in both the myo-inositol and arachidonic acid pathways, resulting in a functional deficiency of prostaglandins at a critical time of neural tube fusion.

Animals↗
PubMed1990

Genetic diversity at an oncogene locus and in mitochondrial DNA between populations of cancer-prone Atlantic tomcod.

It has been reported that Atlantic tomcod (Microgadus tomcod) from the Hudson River exhibit an extremely high incidence of liver tumors. More than 90% of spawning 2-year-old fish display hepatocellular carcinomas. In contrast, representatives of this species from a relatively pristine environment show a much lower incidence of tumors. Genomic DNA and mitochondrial DNA (mtDNA) were isolated from tomcod from the Hudson River, New York, and the Saco River and Royal River, Maine. We found a statistically significant difference in the frequency of PstI-generated restriction fragment length polymorphisms in the abl cellular oncogene between Hudson and Maine tomcod. Allelic variation was observed at two of the three abl domains scored. A single composite genotype seen in approximately 40% of Hudson River fish was seen in only one Maine fish. This polymorphism enabled us to differentiate a Hudson River population from that encountered in the Maine rivers. This is the first demonstration of a population-specific polymorphism at a cellular oncogene locus in any species. In contrast, no restriction site polymorphisms were seen in mtDNA between the populations. The lack of mtDNA diversity in these fish is consistent with the geological history of the area. In combination, these results suggest that the genetic diversity observed at the c-abl oncogene locus must have been a fairly recent event and that oncogene loci may be particularly sensitive to mutational change.

Animals↗
PubMed1990

Popliteal lymph node enlargement induced in syngeneic hosts by T cells from foster-nursed mice.

Splenocytes from adult F1 mice were assayed for their capacity to induce popliteal lymph node enlargement (PLNE) when inoculated in the footpad of identical or reciprocal F1 hosts. The results obtained showed that: (i) T Lyt 1+ splenocytes from adult F1 hybrids were able to induce a significant PLNE when inoculated in reciprocal but not in identical F1 hosts. (ii) Foster-nursing of F1 hybrids on mothers from the paternal strain was able to induce permanent alterations in the ability of their T splenocytes to induce PLNE: Lyt 1+ splenocytes were able to induce significant PLNE in identical but not in reciprocal F1 hosts. Thus, the ability of T splenocytes from foster-nursed F1 hybrids to induce PLNE resembled that observed in reciprocal F1 hybrids nursed by their own mothers. (iii) PLNE was accompanied by cell proliferation involving host B and T lymphocytes. (iv) This PLNE could be detected using F1 hybrids from parental strains differing or not at H-2 antigens but involving a parental strain expressing the stimulatory Mlsa allele and a parental strain bearing the nonstimulatory Mlsb allele while it was not observed in F1 hybrids from parental strains sharing Mlsa antigens.

Animals↗
PubMed1990

Educational intervention as an adjunct to treatment of erectile dysfunction in older couples.

This study examined the effects of a sex and aging workshop highlighting permission and limited information on the sexual knowledge, attitudes, behaviors, and satisfaction of a group of older heterosexual couples experiencing erectile dysfunction. The workshop focused on disseminating information about the physiological and psychological changes that occur in the sexual response during the aging process. Twenty couples participated in this study: 10 attended a workshop and 10 served as controls. The study utilized a randomized control group pretest/posttest design. Workshop participants completed an evaluation form and were interviewed at the time of follow-up. Data analysis revealed that the workshop participants reported significant increases in knowledge levels and in sexual satisfaction. The workshop evaluations and follow-up interviews reinforced these quantitative results. This study lends support to educational intervention as an adjunct to treatment of erectile dysfunction in the elderly population.

Aged↗
PubMed1989

A growth-limiting, mild zinc-deficiency syndrome in some southern Ontario boys with low height percentiles.

A double-blind, pair-matched 12-mo study examined the effects of a zinc supplement (10 mg Zn/d as ZnSO4) on linear growth, taste acuity, attention span, biochemical indices, and energy intakes of 60 boys (aged 5-7 y) with height less than or equal to 15th and midparent height greater than 25th percentiles. Boys with initial hair Zn less than 1.68 mumol/g (n = 16) had a lower mean (+/- SD) weight-for-age Z score (-0.44 +/- 0.59 vs -0.08 +/- 0.84), and a higher median recognition threshold for salt (15 vs 7.5 mmol; p = 0.02) than those with hair Zn greater than 1.68 mumol/g. Only boys with hair Zn less than 1.68 mumol/g responded to the Zn supplement with a higher mean change in height-for-age Z score (p less than 0.05); taste acuity, energy intakes, and attention span were unaffected. A growth-limiting Zn deficiency syndrome exists in boys with low height percentiles, hair Zn levels less than 1.68 mumol/g, and impaired taste acuity.

Body Height↗
PubMed1989

[Ontogeny of T-cell recognition of self histocompatibility antigens: parenteral influences].

The existence of parental influences on the recognition of self histocompatibility was investigated. The results obtained showed that: 1) fetal liver and neonatal splenocytes and thymocytes from F1 mice differed in their capacity to regulate parental alloreactive T reactions against self histocompatibility antigens either of maternal or paternal origin. Fetal and neonatal F1 cells--until day 5--were able to suppress systemic and local GvH reactions induced in F1 hosts with maternal but not with paternal splenocytes; 2) this differential regulatory activity concerning parental GvH reactions against self histocompatibility antigens are correlated with the existence of a differential time lag in the appearance of thymic contrasuppressor activity on maternal anti-paternal and paternal anti-maternal GvH reactivity; 3) splenocytes from reciprocal F1 hybrids--from day 14 onwards--differed in their ability to stimulate F1 T cell proliferation in SMLC reactions; 4) foster nursing of F1 hybrids on mothers from the paternal strain was able to induce permanent alterations in the ability of their splenocytes to stimulate the proliferation of responder F1 T cells. The stimulatory ability of splenocytes from foster-nursed hybrids was indistinguishable from that observed in the reciprocal F1 combination nursed by their own mother, suggesting that lactation would be involved in the differences registered; 5) reciprocal F1 mice differed in their response to conventional antigens presented in the context of parental Ia antigens, lactation also being responsible for the induction of these differences. The different mechanisms involved in the alterations of the outcome of self recognition in the litter are discussed.

Animals↗
PubMed1989

Oropharyngeal mucositis complicating bone marrow transplantation: prognostic factors and the effect of chlorhexidine mouth rinse.

Oral mucosal ulceration complicating bone marrow transplantation interferes with patients' comfort, nutrition and may lead to systemic infection derived from the mouth. The mucosal injury results from epithelial damage due to the cytotoxic effects of chemotherapy and radiation conditioning as well as from superficial oropharyngeal infection. Because chlorhexidine gluconate is a broad spectrum topical antimicrobial which has been demonstrably effective in preventing oral infection and gingivitis, we performed a randomized, placebo controlled, double-blind trial of chlorhexidine as a mouth rinse in BMT recipients to study the severity of oral mucositis and both oral and systemic infectious complications. One hundred patients were randomly assigned to receive either chlorhexidine gluconate 0.12% mouth rinse or placebo three times daily from the initiation (day -8) of chemoradiotherapy conditioning until day +35 post-BMT. Chlorhexidine use resulted in a trend toward improved oral hygiene index (reduced dental plaque) (p = 0.06) but did not modify the oral mucositis. Patients using chlorhexidine developed a maximum ulceration of 18 +/- 22% of their oral mucosa, while placebo patients ulcerated 25 +/- 31% of the mouth. Ulcerative mucositis was significantly worse in adults compared with children, in individuals who received methotrexate for graft-versus-host disease prophylaxis, and was most prominent on non-keratinized epithelium. Overall, there was no clinically demonstrable additional therapeutic advantage to the use of chlorhexidine in either reducing the mucositis, controlling oral pain, facilitating oral nutrition, shortening hospital stay, or reducing oral infection with herpes simplex virus. There was a trend toward diminished oral candidiasis in chlorhexidine users (p = 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Combined anterior and posterior approach to the hip joint in reconstructive and complex arthroplasty.

The combined anterior and posterior approach permits access to the front and back of the hip joint for reconstruction and complex arthroplasty, usually without osteotomy of the greater trochanter, with minimal muscle release. There is ease of access to the anterior and posterior capsule, which can be resected under direct vision, thus permitting accurate hemostasis. The entire acetabular rim is exposed for bone grafting as required. The authors review the useful standard approaches and illustrate the combination of the anterior and posterior approaches through a straight lateral incision. Concomitant exploration of the sciatic nerve is demonstrated, as is the osteotomy of the trochanter performed when the ilium superior to the acetabulum must be reconstructed. The utility and limitations of the operation is illustrated by representative cases. This extensive procedure usually can prevent neurologic and vascular compromise and allows excellent observation of the skeletal structures for accurate component alignment.

Aged↗
PubMed1988

Some aspects of sensory properties of food that relate to food habits and associated problems of elderly consumers.

A questionnaire was developed and administered to 30 elderly consumers to explore perceptions about sensory properties of food that relate to food habits and food-related problems. Fifty percent of the survey sample believed that their food habits had changed considerably in the past 10 years, and 47% believed that health problems influenced their food selection. Few reported changes in food preparation because of mastication problems. Approximately half believed that foods smelled and tasted as good to them now as foods did when the consumers were young. Sensory properties of food were significantly (p less than or equal to .05) more important than several other factors in making purchase decisions for food preparation in three specific social contexts.

Aged↗
PubMed1987

Crystal structure of muconate lactonizing enzyme at 3 A resolution.

The crystal structure of muconate lactonizing enzyme has been solved at 3 A resolution, and an unambiguous alpha-carbon backbone chain trace made. The enzyme contains three domains; the central domain is a parallel-stranded alpha-beta barrel, which has previously been reported in six other enzymes, including triose phosphate isomerase and pyruvate kinase. One novel feature of this enzyme is that its alpha-beta barrel has only seven parallel alpha-helices around the central core of eight parallel beta-strands; all other known alpha-beta barrels contain eight such helices. The N-terminal (alpha + beta) and C-terminal domains cover the cleft where the eighth helix would be. The active site of muconate lactonizing enzyme has been found by locating the manganese ion that is essential for catalytic activity, and by binding and locating an inhibitor, alpha-ketoglutarate. The active site lies in a cleft between the N-terminal and barrel domains; when the active sites of muconate lactonizing enzyme and triose phosphate isomerase are superimposed, barrel-strand 1 of triose phosphate isomerase is aligned with barrel-strand 3 of muconate lactonizing enzyme. This implies that structurally homologous active-site residues in the two enzymes are carried on different parts of the primary sequence; the ancestral gene would had to have been transposed during its evolution to the modern proteins, which seems unlikely. Therefore, these two enzymes may be related by convergent, rather than divergent, evolution.

Binding Sites↗
PubMed1987

The intrinsic synthesis of juvenile hormone-III diol by locust corpora allata in vitro.

Juvenile hormone (JH)-III 10-11-diol is intrinsically synthesized and released from the corpora allata (CA) of adult locust females in vitro, together with JH-III. JH-III synthesis is preferentially stimulated and diol production only slightly enhanced, by cerebral locust allatotropin. The identification of JH-III diol is based on: similar ratio of incorporation of 14C/3H from radiolabelled [2-14C]acetate and [methyl-3H]methionine, to that of JH-III; similar chromatographic properties to those of synthetic diol on an RP-18 column eluted with acetonitrile, and similar chromatographic properties of acetylated derivatives; mass spectrometric analysis of derivatives and fragmentation products. Exogenous radiolabelled JH-III is not degraded during incubation with locust CA in vitro, corroborating the endogenous production of JH-III diol. Allatal diol formation may be an additional mechanism for the control of JH-III levels in locusts, preceding release into the hemolymph.

Animals↗