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Biomedical subjects

S Moore

Publications and source records attributed to S Moore.

At least 307 records · Page 17Linked to original sources

A platelet-derived factor chemotactic for rabbit arterial smooth muscle cells in culture.

Following endothelial injury in a blood vessel, intimal proliferation of smooth muscle cells is preceeded by platelet adherence to the subendothelium and migration of cells from the media. Factors released from platelets were examined for their ability to induce directed migration of smooth muscle cells across a filter in a modified Boyden chamber. Thrombin and collagen induced the release of a nondialysable, heat stable chemotactic factor from washed rabbit platelets. Release of this factor does not depend on primary aggregation but is associated with the release reaction and is independent of products derived from the metabolism of arachidonic acid. Directed migration of the smooth muscle cells in response to the platelet-derived chemotactic factor does not require the presence of serum.

Animals↗

Effects of complete or partial occlusion of a coronary artery.

We investigated the effects of a partial compared to a complete thrombotic occlusion of the left anterior descending coronary artery in dogs. A completely occlusive thrombus was associated with a full thickness myocardial infarction. Mural thrombus was associated with focal areas of myocardial injury, mainly subendocardial in location. The findings are compatible with the concept that mural thrombus can give rise to platelet or platelet-fibrin emboli in the microcirculation which cause focal areas of ischemic damage. This pathogenesis was further explored using a thrombogenic wire placed in the left anterior descending coronary artery by indirect technique. Five of 10 dogs had developed a completely occlusive thrombus, whereas five had a mural thrombus at death, which occurred within 2 days. Three of the five dogs with mural thrombus had focal ischemic myocardial damage and platelet-fibrin thrombi; the other two that died early showed only platelet fibrin masses in the microcirculation. When platelets were labeled with 111Indium, there was increased radioactivity in the territory of the myocardium served by the artery containing a developing thrombus.

Animals↗

William H. Stein.

Explore the source record for details and available documents.

Biochemistry↗

Identification of 2':3'-cyclic nucleotide 3'-phosphodiesterase in the vertebrate retina.

The enzyme, 2':3'-cyclic nucleotide 3'-phosphodiesterase (2':3'-cNMP-3'-ase) has been used as a marker in the nervous system for the presence of myelin membrane or myelin-producing glial cells. In this study, goldfish and bovine neural retinas are found to have high levels of such a diesterase activity. Analysis of retinal tissue incubated with 2':3'-cAMP shows only 2'-AMP as the reaction product, indicating the selective hydrolysis of the cyclic nucleotide. Microdissection of the goldfish retina demonstrates the highest 2':3'-cNMP-3'-ase activity in the region of the photoreceptors. A fraction enriched in bovine rod outer segments has about a 5-fold increase in specific enzyme activity when compared to whole retina preparations. These data suggest that 2':3'-cNMP-3'-ase is either closely associated with or is an intrinsic feature of vertebrate photoreceptor elements. The retina, which contains this enzyme, may serve as a model to investigate the influence of 2':3'-cyclic nucleotides on a function of the nervous system.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗

Dissociated vertical deviation. Treatment with the faden operation of Cuüppers.

Thirty-four patients (49 eyes) who had dissociated vertical deviation were treated with faden operation of Cüppers. The median follow-up period was 14 months. The operation produced good results in 23 of the patients, some improvement in seven, and did not help four. The posterior fixation suture was placed 14 mm behind the superior rectus muscle insertion and the superior rectus muscle was recessed.

Adolescent↗

Ribonuclease inhibitor from bovine brain.

A ribonuclease inhibitor from bovine brain has been purified 27 000-fold by affinity chromatography on Sepharose-RNase A with an overall yield of 46% (ca. 0.4 mg/kg tissue). The purified inhibitor gives a single band by SDS-gel electrophoresis. By gel filtration the molecular weight is ca. 50 000; the molecular weight of the complex with bovine pancreatic RNase A is ca. 62 000, indicative of 1:1 binding on a molar basis. The inhibition of the action of RNase A on yeast RNA by the inhibitor is noncompetitive with a Ki of 7 x 10(-10) M. The protein is very similar in its properties, including amino acid composition, to the inhibitor previously isolated from human placenta. The amount of inhibitor per g of protein in bovine brain is about one-seventh of the value for human placenta. No difference was found in the distribution of inhibitor between white and gray matter; one-tenth of the inhibitor present is bound to a brain ribonuclease which is released in active form after reaction with p-hydroxymercuribenzoate. Essentially no free neutral ribonuclease activity could be detected in brain homogenates in the absence of p-hydroxymercuribenzoate.

Amino Acids↗

N-Terminal sequence of human big gastrin: sequence, synthetic and immunochemical studies.

The previously assigned structure of human big gastrin is revised as a result of sequencing and immunological studies on synthetic peptides. A nonadecapeptide has been synthesized and found to have full immunochemical potency compared with natural human G34 in a radioimmunoassay which is specific for the N-terminal sequence. Syntheses of the peptides were achieved using the stepwise procedure with benzyloxycarbonyl-amino acids and fragment couplings mediated mainly by the dicyclohexylcarbodiimide procedure in the presence of either N-hydroxysuccinimide or 1-hydroxybenzotriazole. Purification of the peptide fragments was by Sephadex LH-20 chromatography and removal of protecting groups was effected using 90% trifluoroacetic acid in the presence of scavengers. Purification of the nonadecapeptide was achieved by high performance liquid chromatography.

Amino Acid Sequence↗

Critical light reflection at a plastic/glass interface and its application to foot pressure measurements.

The necessary properties of plastic materials for use in a method of foot pressure distribution measurements have been assessed, and the mechanisms in operation at an illuminated plastic to glass interface underload have been investigated. A hypothesis is given of the physical principles upon which the operation of this technique is based and it is shown that a calibrated analysis of both the static and dynamic distribution of pressure under the foot is possible by this technique.

Biomechanical Phenomena↗

Glycosaminoglycan distribution in rabbit aortic wall following balloon catheter deendothelialization. An ultrastructural study.

The glycosaminoglycan (GAG), content of rabbit aortic wall was assayed morphometrically using ruthenium red-stained sections viewed by transmission electron microscopy. Two types of ruthenium red-positive granules were identified in the intercellular matrix. Large granules (20 to 50 nm. in diameter) with interconnecting fibrils were removed by digestion of the tissue with testicular hyaluronidase or chondroitinase ABC. Smaller granules (20 nm). were localized mainly in endothelial basement membrane and were resistant to digestion by these enzymes. Both types of granules were removed from the tissue by the action of nitrous acid. At intervals of 11 to 17 weeks after a single balloon deendothelialization of the aortas of normolipemic rabbits, there were significantly more granules of both types in areas where endothelium had regenerated over the neointima than in areas not covered by endothelium. Lipid also accumulated preferentially in the endothelium-covered neointima. Compared to normal aortas, there is an increase in the large granule content in the reendothelialized areas and a decrease in both large and small granule content in the nonendothelialized areas. It is suggested that GAG may trap low density lipoproteins. The low GAG content of the nonendothelialized neointima may account for the low lipid content; additionally, the lack of endothelial cover may allow diffusion of GAG out of these areas carrying low density lipoprotein into the blood stream in the form of GAG-low density lipoprotein complexes or low density lipoprotein removal may be facilitated by high density lipoprotein.

Animals↗

Levamisole reduces the thrombocytopenia associated with myxovirus vaccination.

Mature dogs were vaccinated with a myxovirus vaccine. At this time, half of the dogs were also given a subcutaneous injection of levamisole hydrochloride (2.2 mg/kg). Blood platelets were counted daily. The dogs that had received only the vaccine showed, after 48 hours, a 48% decrease in platelets. Levamisole reduced the thrombocytopenia associated with myxovirus vaccination. Levamisole could have a protective effect on platelets by preventing their aggregation induced by viral neuraminidase.

Animals↗

The primary care network--a new type of HMO for private practice physicians.

A new type of health maintenance organization has been developed to encourage primary care physicians in private practice to become coordinators and financial managers for all medical care. Each patient chooses one internist, family or general physician, or pediatrician and must be referred by that physician for all hospital admissions and care by specialists. The primary care physician authorizes all payments from his own account for care provided to his patients. He shares any deficit or surplus remaining at the end of the year. Hospital admission rates and length of stay are lower than those of Blue Cross, with only one of three dollars paid to hospitals. The plan is providing care to 38,000 persons with 750 participating physicians in Northern California, Washington and Utah. This plan represents an attempt by physicians to control costs without government regulation.

Cost Control↗

Cost containment through risk-sharing by primary-care physicians.

A new type of independent practice association has been organized to encourage primary-care physicians in private practice to become coordinators and financial managers for all medical care. Each patient chooses one internist, family or general physician or pediatrician and must be referred by that physician for all specialized care. The primary-care physician authorizes payment from his own account for all care provided to his patients. He shares any dificit or surplus remaining at the end of the year. After four years of operation, United Healthcare has 610 primary-care physicians treating 23,000 patients. Total hospital use during 1978 and 293 bed-days per 1000 patients, as compared with 479 for Blue Cross. The hospital-admission rate per 1000 was 88, as compared with 101 for Blue Cross. Average lengths of stay were 3.3 and 4.7 dyas, respectively. This plan represents another means to control costs in the private medical marketplace.

Consumer Behavior↗

Strabismus in the aphakic patient.

Fifty patients with aphakia and strabismus were studied. The chief complaint was diplopia following full optical correction. Prism therapy was recommended if the diplopia persisted after 3 to 4 months. When prism therapy was ineffective or impractical, surgery was recommended. The result of therapy was not influenced by the cause of the cataract treatment was considered successful in approximately 80% of patients. Patients who had convergence insufficiency did well with prism therapy alone. Half of the patients who had divergence excess needed extraocular-muscle surgery. One fourth of the patients had esotropia, nearly half associated with lateral rectus palsy. While prism therapy resulted in fusion, a reduction in prism power was not tolerated in this group. For this reason, surgery was suggested for all patients who had esotropia.

Adolescent↗

Effect of cold submersion on intramuscular temperature of the gastrocnemius muscle.

This study investigated the effect of a 30-minute, 10 degrees C water bath on the intramuscular temperature of a lower leg and the contralateral lower leg. Intramuscular temperature was measured in 10 subjects using hypodermic thermistor probes inserted 25.3 mm into the lateral head of the gastrocnemius muscles of both legs. One lower leg was submersed in a 10 degrees C cold bath with the water level maintained 5 cm above the patella and with the subject in a nonweight-bearing position. Intramuscular temperature significantly decreased in both lower legs during treatment, although the intramuscular temperature of the treatment lower leg was significantly lower than that of the contralateral lower leg. A temperature difference continued for four hours after treatment; however, the temperature of both lower legs was significantly lower after four hours than it was before the cold bath treatment.

Adipose Tissue↗

Minigastrin; corrected structure and synthesis.

Evidence is presented that minigastrin is the C-terminal tetradecapeptide amide of gastrin and not the tridecapeptide amide as previously reported. Synthesis of the tetradecapeptide amide sequence, Trp-Leu-[Glu]5-Ala-Tyr-Gly-Trp-Met-Asp-Phe-Nh2, was achieved by a series of fragment couplings which were mediated by the dicyclohexylcarbodiimide procedure in presence of either N-hydroxysuccinimide or 1-hydroxybenzotriazole. Purification of all intermediate fragments, and of the final protected tetradecapeptide amide, was by Sephadex LH-20 chromatography. Removal of the protecting groups was effected by treatment with 90% trifluoroacetic acid in the presence of a large excess of scavengers. Purification by ion-exchange chromatography afforded the pure tetradecapeptide amide. This material had full physiological activity.

Amino Acid Sequence↗