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Biomedical subjects

M Murphy

Publications and source records attributed to M Murphy.

At least 505 records · Page 28Linked to original sources
PubMed1979

Patterns of skin injury in nonaccidental and accidental injury.

The patterns of soft tissue injuries in a group of 154 children reported to protective services for child abuse or neglect were compared with patterns of soft tissue injury found in a group of 91 emergency room patients who sustained an accidental injury and 105 children seen in a pediatric ambulatory clinic. All children in the three groups were 1 to 12 years old. Children in the suspected child abuse and neglect group had significantly more (P less than .01) soft tissue injuries over the cheeks, trunk, genitals, and upper legs. Lacerations were significantly more common (P less than .001) in the emergency room group.

Accidents↗
PubMed1978

The identification of the products of folate catabolism in the rat.

Further analysis of rat urine containing labelled catabolites derived from administered 3H- or 14C-labelled folic acid is described. The results support previously described studies, and show that folate catabolism in the rat takes place by cleavage of the C9-N10 bond, and not by excretion of inactive forms of the vitamin which still contain the intact folate skeleton.

Animals↗
PubMed1978

Clinical and immunological study of percutaneous revaccination in children who originally received smallpox vaccine subcutaneously.

In a large multicenter smallpox vaccination study carried out from 1970 to 1973, it was found that 39% of children who were initially immunized by the subcutaneous route and then challenged percutaneously with a standard vaccination did not have measurable neutralizing antibody upon follow-up. Because of this finding, a percutaneous revaccination study was conducted at the St. Louis study center in 1975 and 1976. There were four study groups, which were composed on the basis of route of primary immunization (subcutaneous or percutaneous) and whether neutralizing antibody was detectable following the original percutaneous challenge immunization. Of 52 children revaccinated, all but four had accelerated reactions. There was no difference in size of lesions or day of maximum erythema among the four study groups. Only 66% of children originally vaccinated subcutaneously who did not have postchallenge neutralizing antibody had measurable neutralizing antibody following revaccination. Transformation studies with vaccinia viral antigen before and after revaccination were performed on lymphocytes from 50 children. There was no appreciable differences in responses either before or after revaccination when the four groups were compared. However, the mean stimulation ratio for the total group increased from 2.4 before revaccination to 4.6 3 weeks later. In primary subcutaneous vaccine recipients without pre-revaccination neutralizing antibody, lymphocyte transformation correlated directly with the neutralizing antibody response.

Antibodies, Viral↗
PubMed1977

Somatostatin inhibition of glucose-induced electrical activity in cultured rat islet cells.

Electrophysiological studies of rat islet cells in monolayer culture were undertaken to determine the role of transmembranous ionic fluxes in the inhibitory action of somatostatin on insulin release. In the presence of somatotropin release inhibiting factor (SRIF) (2.5 nM), hyperpolarization occured with or without glucose (16.6 mM) in the medium. SRIF also inhibited the incidence of glucose-induced spike activity. The inhibitory action of SRIF occurred within 5 min and was readily reversible. An increase in extracellular K+ (5-13 mM) or Ca2+ (2.3-4.6 mM) prevented SRIF inhibition of glucose-induced electrical activity. The secretory response of cultured islets to glucose (16.6 mM) was completely inhibited by SRIF (2.5 nM). The presence of high [Ca2+]o or [k+]o enhanced insulin release in the presence of SRIF and glucose. Although phentolamine (5.0 microgram/ml) did not block the inhibition of glucose-induced electrical responses by SRIF, it prevented the inhibitory action of epinephrine (0.2 microgram/ml). It is concluded that the primary action of SRIF is to alter transmembranous cationic fluxes, as manifested by hyperpolarization and a decrease in the incidence of spike activity, which may prevent glucose from eliciting a normal secretory response.

Action Potentials↗
PubMed1976

Exchange of phospholipids between mitochondria and microsomes in vitro stimulated by yeast cell cytosol.

Yeast cell cytosol stimulated the exchange of phospholipids between yeast mitochondria and microsomes in vitro, and also between organelles isolated from rat liver. The major phospholipids exchanged in both cases were phosphatidylinositol and phosphatidylcholine, together with smaller amounts of phosphatidylethanolamine. Evidence was also obtained that interconversion of phospholipids occurred during the incubation, probably via base exchange mechanisms.

Animals↗
PubMed1976

The use of a single venous blood sample to assess oxygen binding in haemoglobin.

The measurement of pH, PO2, PCO2 and SO2 in a single venous blood sample can be used to determine the P50 at standard or at in vivo conditions. This technique makes it feasible for a physician, firstly, to make an assessment of the net adaptation of the red cell to reductions in blood oxygen content or flow and, secondly, to make an initial assessment of whether a haemoglobin with altered affinity for oxygen is present in subjects with polycythaemia or anaemia.

Acidosis↗
PubMed1976

Defective bud formation in human cells chronically infected with subacute sclerosing panencephalitis virus.

Human prostate cells chronically infected with the Mantooth strain of subacute sclerosing panencephalitis (SSPE) virus multiply normally, fuse only occasionally to form giant cells, and yet have twisted intracytoplasmic nucleocapsids. These cells are able to support replication of vesicular stomatitis virus, although they release only small amounts of SSPE virus. To determine why carrier cells do not produce virus, they were examined with techniques for surface replication, freeze-fracturing, and immunoperoxidase labeling with SSPE antibody. The surface of carrier cells, like that of productive cells, is characterized by ridges crowned with viral antigens and devoid of the intramembrane particles revealed by freeze-fracture techniques. Since surface ridges form where nucleocapsids attach to the membrane, the shape and length of ridges are indicative of the shape and length of the underlying nucleocapsid. Whereas ridges on productive cells are serpentine in shape, those on carrier cells are typically straight or hairpin shaped, and the hairpin ridges are twice as long as serpentine ridges on productive cells. Furthermore, the spacing between ridges on carrier cells is never as small as that in productive infections, so that continuous sheets of viral membrane are never formed. The majority of carrier cells lack the round viral buds observed in productive cells but have, instead, many elongated processes attached to the cell surface. Each of these processes contains one or two hairpin ridges overlying hairpin-shaped nucleocapsids. These "hairpin buds" are restricted to a single region of the carrier cell surface, whereas viral buds are distributed over the entire surface of productive cells. Thus, there are several structural defects in carrier cells that depend on the specific interaction of a certain viral strain with a certain cell type. These defects prevent the deployment of viral antigen in some regions of the cell surface, the formation of nucleocapsids of normal length, the coiling of attached nucleocapsids, and the consolidation of sheets of viral membrane into spherical buds with the nucleocapsids coiled inside. These defects may account for the failure of carrier cells to shed infectious virus.

Antigens, Viral↗
PubMed1974

The relationships between arterial oxygen flow rate, oxygen binding by hemoglobin, and oxygen utilization after myocardial infarction.

The interrelationships of arterial oxygen flow rate index, oxygen binding by hemoglobin, and oxygen consumption have been examined in patients with acute myocardial infarction. Proportional extraction of oxygen increased in close association with decreasing oxygen flow rate, and hence, whole body oxygen consumption was constant over nearly a three-fold variation in arterial oxygen flow rate. A reduction in hemoglobin-oxygen affinity at in vivo conditions of pH. Pco(2) and temperature also occurred in proportion to the reduction in arterial oxygen flow rate. Therefore, the increased proportional removal of oxygen from arterial blood at low oxygen flow rates, required to maintain oxygen consumption, may have been facilitated by the reduced affinity of hemoglobin for oxygen at in vivo conditions. However, the decrease in affinity did not appear to explain more than 30-40% of the increased extraction. Respiratory alkalosis was a frequent occurrence in these patients and 2,3-diphosphoglycerate was positively associated with blood pH as well as with the time-averaged proportion of deoxyhemoglobin in arterial and venous blood.Hemoglobin-oxygen affinity measured at standard conditions and the mixed venous oxygen saturation were equally good indicators of reduced arterial oxygen flow rate in patients without shock. However, Svo(2) is more easily measured and is a more useful indicator of reduced oxygen flow rate, since its relationship to oxygen flow appears to be independent of affinity changes and time.

Adult↗