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Biomedical subjects

M Williams

Publications and source records attributed to M Williams.

At least 703 records · Page 39Linked to original sources
PubMed1980

Hypogammaglobulinemia in patients with cystic fibrosis.

To investigate some aspects of immune function in cystic fibrosis, we measured serum immunoglobulins in 419 patients. Twenty-two per cent of the 154 patients less than 10 years old had hypogammaglobulinemia-G, whereas the older patients had normal or elevated serum immunoglobulins. A single mechanism accounting for the extraordinary prevalence of hypogammaglobulinemia in young patients with cystic fibrosis was not defined in studies of T and B-lymphocyte function in vitro or in studies of IgG metabolism in vivo. Analysis of objective clinical data, including arterial blood gases, chest roentgenograms, and bacteriologic cultures, indicated that the patients with hypogammaglobulinemia had significantly less severe lung disease than did age-matched patients with cystic fibrosis and normal or elevated IgG levels. We conclude that progression of lung disease may be due in part to a hyper-immune response.

Adolescent↗
PubMed1980

Fine structure of an octopaminergic neuron and its terminals.

The large octopaminergic dorsal unpaired median neuron of the locust that innervates the extensor tibiae muscle, DUMETi, was examined electronmicroscopically. Its soma contains many Golgi complexes apparently making dense-core vesicles similar to those found in peripheral branches and terminals. There are also larger stores of the dense material in the soma, especially near the exit of the principal neurite, that are not in vesicular form. Since the neurons can be penetrated and stimulated by microelectrodes, they form favorable subjects for direct studies of the control of neurosecretion. Preterminal fine branches of the neuron were located in proximal outer bundles of muscle fibers into which they had been traced electrophysiologically. They contain numerous large dense-core vesicles arrayed in rows near microtubules. These fine branches have a thick layer of collagenous connective tissue between the axon and the muscle fiber. Final terminals have varicosities containing many vesicles, lying inside the outer layers of the sarcolemmal complex of muscle fibers. They do not form synaptic structures. Terminals of another DUM neuron, one that innervates the dorsal longitudinal flight muscles (DUMDL), were similar in detail to those of DUMETi. DUMETi swelled about 20-fold in cross-sectional area above a ligature, in a 12-hr period, indicating that there is an extensive centrifugal flow of material in it, and sprouted a branch.

Animals↗
PubMed1980

Malignant properties and DNA content of daughter clones from a mouse fibrosarcoma: differentiation between malignant properties.

Freshly isolated cones of high cloning efficiency from a mouse fibrosarcoma were examined for DNA content, cell size, protein content, and malignant characteristics such as artificial lung-colony-forming ability, s.c. tumour take, host survival, and spontaneous metastatic ability. These malignant characteristics and other cell properties were heterogeneous among these clones; the malignant characteristics could vary and were not "all or none" in their nature. The higher the DNA content or the larger the cell volume, the higher the malignancy in terms of artificial lung-colony forming, efficiency, s.c. tumour take, and host survival. Despite variability of each parameter, the ratio of DNA content to cell size or protein content remained constant through these variations: the increased DNA paralleled increased protein and increased cell volume. The increased DNA was correlated with the more malignant characteristics of local growth and lung-colony-forming efficiency. Spontaneous metastasis to the lung was totally different from the local growth abilities; the small-cell clone produced more metastases. The graded nature of malignant properties and the differentiation between local growth and metastatic potential among the daughter clones indicate that malignancy reflects a complex moiety of cell properties.

Animals↗
PubMed1980

Biochemical characterization of putative central purinergic receptors by using 2-chloro[3H]adenosine, a stable analog of adenosine.

After pretreatment of rat brain synaptic membranes with adenosine deaminase to remove endogenous adenosine, 2-chloro[3H]adenosine, a stable analog of adenosine, binds to two sites with Kd values of 1.3 and 16 nM and corresponding Bmax values of 207 and 380 fmol/mg of protein. Binding is reversible, and the highest density of sites occurs in enriched synaptosomal fractions. In peripheral tissue, negligible binding is observed in heart, kidney, and liver, while testicle has 11 fmol of binding sites/mg of protein. In brain, caudate and hippocampus have the highest density of sites, and spinal cord and hypothalamus have the lowest. This high-affinity binding is stereospecific; the L diasteromer of N6-phenylisopropyladenosine is approximately 30-times more potent as a displacer of 2-chloro[3H]adenosine than the D isomer and is also sensitive to theophylline (IC50 = 8.8 microM) and other purine-related compounds. Several putative neurotransmitters, neurotransmitter antagonists, and other centrally active compounds have no effect on binding. The data are consistent with the hypothesis that 2-chloro[3H]adenosine is binding to central purinergic receptors.

Adenosine↗
PubMed1980

48-hour cephradine and post-prostatectomy bacteriuria.

In a randomised, controlled trial of intramuscular cephradine given in a dose of 1 g 6-hourly for 48 h, there was a significant reduction in the incidence of significant bacteriuria after transurethral resection. In contrast, the incidence of significant bacteriuria after open prostatectomy was unchanged. Post-operative complications were reduced in patients who received cephradine. The use of short-term cephradine would appear to be justified.

Aged↗
PubMed1979

Enhancement of in vitro binding and some of the pharmacological properties of diazepam by a novel anthelmintic agent, Avermectin B1a.

A novel macrocyclic lactone disaccharide anthelmintic agent, Avermectin B1a (AVM) has been found to cause a concentration-dependent increase in the in vitro binding of 3H-diazepam to rat and mouse brain membranes. The increase in binding is manifested as both an increase in the affinity and number of bindings sites for 3H-diazepam. Preliminary in vivo studies demonstrate that AVM can also enhance some of the pharmacological actions of diazepam.

Animals↗
PubMed1979

Protein phosphorylation in rat caudate homogenate: stimulatory effects of dopamine and enhancement of dopamine response following 6-hydroxydopamine treatment.

Dopamine (3-hydroxytyramine) stimulates the incorporation of 32P into proteins endogenous to a homogenate of rat caudate nucleus when 10 microM [gamma-32P]-ATP is used as a substrate following preincubation with 400 microM ATP. The increase in 32P incorporation has pharmacological characteristics similar to caudate tissue. Chronic depletion of striatal dopamine in vivo by stereotaxic injection of 6-hydroxydopamine in the nigrostriatal pathway results in a significant enhancement of the dopamine stimulation of 32 p incorporation in vitro. Cyclic AMP-stimulated phosphorylation of caudate proteins remains unchanged following 6-hydroxydopamine treatment.

Adenosine Triphosphate↗