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Biomedical subjects

N J Marsh

Publications and source records attributed to N J Marsh.

9 recordsLinked to original sources
PubMed1998

Vulnerability to stressor-induced disturbances in self-stimulation from the dorsal and ventral A10 area: differential effects of intraventricular D-Ala2-Met5-enkephalinamide, D-Ala2, N-Me-Phe4, Gly-Ol5-enkephalin, and D-Pen2, D-Pen5-enkephalin administration.

D-Ala2-Met5-enkephalinamide (DALA) (1.0 microg/microl) was administered intraventricularly to mice responding for electrical stimulation from the dorsal or ventral aspects of the VTA immediately prior to footshock (Experiment 1). Predictably, footshock reduced self-stimulation from the dorsal but not the ventral VTA immediately, 24, and 168 h following the stressor. Intraventricular DALA administration effected a partial attenuation of stressor-induced self-stimulation reductions from the dorsal VTA immediately and 24 h poststressor. Deficits appeared among DALA-Shocked mice responding for brain stimulation from the ventral VTA during comparable test intervals. The long-term depressant influence of footshock on self-stimulation from the dorsal VTA was abolished among DALA-treated mice and DALA-associated reductions in self-stimulation from the ventral A10 region among stressed mice were not evident 1 week later. Administration of D-Ala2, N-Me-Phe4, Gly-Ol5-enkephalin (DAGO) (0.01 microg/microl) or D-Pen2, D-Pen5-enkephalin (DPDPE) (1.0 microg/microl) intraventricularly prior to footshock effected an immediate and a delayed antagonism, respectively, of the stressor on self-stimulation from the dorsal VTA, which persisted for 1 week. Prophylactic administration of 0.001 microg/microl DAGO or 0.01 microg/microl DPDPE prior to the stressor failed to influence self-stimulation from the ventral VTA (Experiment 2). Administration of 0.01 microg/microl DAGO or 1.0 microg/microl DPDPE among mice responding for brain stimulation from the dorsal VTA following footshock produced a weak therapeutic effect immediately poststressor, but effected protracted amelioration of footshock-induced reductions of self-stimulation from the dorsal VTA (Experiment 3). Taken together, mu, delta, and mu-delta activation influenced self-stimulation differentially from the dorsal and ventral VTA according to the temporal order of opioid peptide challenge relative to stressor imposition. These data are discussed with respect to stressors, motivational alterations, and the putative modulating influence of endogenous enkephalin activity in subareas of the VTA.

Animals↗
PubMed1993

Effectiveness of the use of humor in the rehabilitation of people with SCI: a pilot study.

Despite the empirically established beneficial effects of laughter on psychological health, humor remains a much neglected area of research. This study examined the psychological impact of humor on people with SCI, the hypothesis being that it would significantly reduce the deleterious psychological effects of the injury. Mood state, frequency of intrusive thoughts and avoidance behavior of eight male inpatients at the National Spinal Injuries Centre were monitored before and after exposure to a series of five humorous video presentations. Although differences in these parameters were in the predicted direction, statistical analysis revealed no significant effect. Nevertheless, this pilot study highlighted pertinent issues and suggested modifications for further exploration.

Adolescent↗
PubMed1983

The protein composition of the ocular zonules.

Bovine and human zonules were found to be composed of noncollagenous acidic glycoprotein with a high cysteine content, double that previously reported. In reduced zonular fractions the most prominent peptide had a molecular weight (MW) of approximately 70,000. Lesser quantities of 170,000, 50,000, and 35,000 dalton peptides were also present and a variable number of lower MW bands, depending upon the degree of reduction and denaturation. A fraction of bovine zonules soluble in low ionic strength buffers contained primarily a peptide of approximately 50,000 daltons, often present as a doublet. Amino acid and hexosamine content of these two fractions was consistent with the presence of at least two different glycoconjugates, one a proteoglycan. Carbohydrate analysis of whole zonules suggested that these glycoconjugates include a sialofucose-containing glycoprotein and a lesser quantity of xylose-containing proteoglycan. The amino acid profile and peptide content of the zonules resembled that of elastic tissue microfibrils, increasing further the possibility of a close relationship between these two fibrils.

Adult↗
PubMed1981

Elevated serum creatine phosphokinase in subjects with McLeod syndrome.

McLeod phenotype red cells of the Kell blood group system have acanthocytic morphology and reduced in vivo survival. The phenotype has an X-linked mode of inheritance and is found in some males who have no abnormality of leukocyte function and in some who have X-linked chronic granulomatous disease (CGD). We now describe an association between the McLeod phenotype and an abnormal elevation of serum creatine phosphokinase (CPK). The increase is of the MM isoenzyme type, derived from skeletal muscle or cardiac muscle, and muscle biopsy shows evidence of muscle cell changes. All of 11 males who have McLeod syndrome but do not have CGD have high levels of serum CPK. Males with McLeod syndrome and CGD may have normal or high levels of the enzyme. Individuals with other variant phenotypes in the Kell system have normal levels of serum CPK. Studies on a large kindred, which includes 5 people of McLeod phenotype, show high CPK levels only in the members of McLeod type. We conclude that the high level of CPK in the serum of these people is a reflection of a muscle cell anomaly and that in these individuals it is a pleiotropic effect of the X-linked gene that produces the McLeod red cell phenotype.

Anemia, Hemolytic, Congenital↗
PubMed1972

Ordering of mutant sites in the isoleucine-valine genes of Escherichia coli by use of merogenotes derived from F 14 : a new procedure for fine-structure mapping.

F-merogenotes derived from F(14) by transductional shortening have previously been found to consist of the sex factor plus one or more of the ilv genes. It is shown here that they carry one or more ilv genes and a variable portion of the adjacent proximal ilv gene. This observation was used to develop a method, analogous to deletion mapping, for ordering mutant sites within the ilv genes. This method requires the use of a series of merogenotes each carrying an increasingly longer segment of the gene being mapped. A simplified method of fine-structure mapping is also described which requires only one or two F' donor strains to map any one gene. This method is based on the large differences observed in recombination frequencies for mutant sites at various distances from the origin of the incomplete merogenote gene. The sequence of 25 mutant sites within three of the ilv genes was determined by use of the simplified procedure.

Chromosome Mapping↗