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Biomedical subjects

H Gould

Publications and source records attributed to H Gould.

71 records · Page 4Linked to original sources
PubMed1973

Transcription of rat-liver chromatin with homologous enzyme.

The product of transcription of rat-liver chromatin with homologous rat-liver Form-B polymerase in vitro is high molecular weight RNA with sedimentation coefficients principally in the range of 18-45 S. The average size is somewhat smaller than that of the heterogeneous high molecular weight RNA synthesized by the endogenous enzyme in vivo (or in isolated nuclei). We have excluded the possibility that this difference can be attributed to degradation of the nascent RNA occurring under the conditions of our experiments. The size of the RNA produced by the homologous enzyme nevertheless approaches that of the natural transcripts much more closely than does that of the RNA produced by bacterial RNA polymerases, which we, in addition to other authors, have found to sediment around 10 S.

Animals↗
PubMed1965

A comparison of methods for the isolation and fractionation of reticulocyte ribosomes.

1. Polysomes, ribosomes and pH5 enzymes were isolated from rabbit reticulocytes by acidifying the post-mitochondrial supernatant to pH6.0 to precipitate all ribonucleoprotein particles and about half the pH5 enzymes; the precipitate was redissolved in buffer, pH7.6, and fractionated by zone centrifuging. 2. The isolation of polysome-rich and ribosome-rich fractions from the post-mitochondrial supernatant was also examined. 3. Studies of the stability of polysomes revealed that dissociation into sub-units occurred when both bound and free Mg(2+) was chelated by EDTA or when the pH was increased above pH8.8.

Animals↗
PubMedDate not supplied

Selective unfolding of erythroid chromatin in the region of the active beta-globin gene.

Globin gene expression, which occurs exclusively in the erythroid cell lineage, is controlled at the level of transcription. It is thus of some considerable interest to compare the chromatin structure of this gene with that of inactive genes in erythroid cell nuclei and to compare the chromatin structure of the globin gene in its active and inactive states in nuclei of different cell types. Other workers have observed that globin genes in erythroid cell nuclei exhibit the enhanced overall sensitivity to nucleases and the hypersensitive site in the 5'-flanking sequence typical of many active genes. The nature of the structural changes giving rise to nuclease sensitivity are however obscure. We have investigated the local higher order structure of chromatin in the region of unique genes in chicken by sucrose gradient sedimentation of chromatin restriction fragments. We find that ovalbumin and alpha 2-collagen gene fragments in erythrocyte chromatin and an adult beta-globin gene fragment in spleen chromatin sediment with bulk chromatin fragments of the same DNA size, whereas the beta-globin gene fragment in erythrocyte chromatin sediments more slowly than bulk fragments of equivalent size. The simplest interpretation of the results is that the solenoid structure in the region of the globin gene is selectively and permanently unfolded on gene activation.

Animals↗
PubMedDate not supplied

Inhibition of the Prausnitz-Küstner reaction by an immunoglobulin epsilon-chain fragment synthesized in E. coli.

The Prausnitz-Küstner (P-K) reaction is a sensitive test for the presence and activity in the skin of immunoglobulin E, an important class of immunoglobulin mediating allergic reactions. A fragment of the human myeloma ND epsilon-chain gene, encoding the second, third and fourth domains of the IgE constant region (C epsilon 2-4) was assessed here for its ability to inhibit the P-K reaction in vivo. Injection of the fragment in skin sites of healthy human adults prevented subsequent sensitization with serum containing IgE antibody to ragweed antigen. Inhibition of the P-K reaction required a 200-fold molar excess of the C epsilon fragment over the IgE present in the sensitizing serum. The efficacy of the C epsilon fragment in inhibiting the P-K reaction compared favourably with that of natural myeloma IgE (PS) in terms of both blocking concentrations and duration of the blocking effect. The inhibition of the P-K reaction by C epsilon 2-4 fragments was specific and probably caused by the saturation of IgE receptors on mast cells by the recombinant gene product.

Escherichia coli↗
PubMedDate not supplied

A conceptual model for the recruitment of diverse women into research studies.

Researchers' understanding of recruitment and retention of study subjects is in its infancy. To address the dearth of information on the underrepresentation of diverse populations of women in research studies relating to health issues, the University of California, San Francisco (UCSF) National Center of Excellence in Women's Health completed a comprehensive examination of issues related to recruitment. By synthesizing data from literature reviews, focus groups, surveys, one-on-one interviews, and direct experience recruiting diverse populations of women for research, a conceptual model was developed. This model outlines the interplay of three factors found to be relevant to the recruitment of diverse populations of women into research studies: awareness, acceptance, and access. Practical examples of cost-effective recruitment strategies to be considered for implementation to increase the presence of awareness, acceptability, and access are included in this report.

Adult↗
PubMedDate not supplied

Retrorectal cyst-hamartomas: CT diagnosis.

Retrorectal cyst-hamartomas (RRCH) are congenital lesions characterized by the presence of cysts lined by multiple types of epithelium, often predominantly mucin-secreting. Three cases of RRCH are presented with their associated histologic and CT findings. The lesion requires complete surgical excision to prevent complications of recurrence, infection, or metastasis.

Adult↗
PubMedDate not supplied

Does laser trabeculoplasty prevent steroid glaucoma?

OBJECTIVE: To investigate the effect of laser trabeculoplasty in the normal myopic eye on steroid intraocular pressure responsiveness in patients undergoing radial keratotomy. MATERIALS AND METHODS: Diode laser trabeculoplasty was performed on 94 patients with myopia undergoing radial keratotomy who were then started on dexamethasone drops. Intraocular pressures were measured by applanation tonometry compensated for corneal flattening. RESULTS: Twenty-eight percent of patients had an intraocular pressure increase of 6 mm Hg or more by the fourth week. CONCLUSION: Laser trabeculoplasty does not prevent steroid intraocular pressure increase in patients with myopia.

Administration, Topical↗