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Biomedical subjects

J Stevenson

Publications and source records attributed to J Stevenson.

At least 199 records · Page 11Linked to original sources
PubMed1985

The effect of high energy (HZE) particle radiation (40Ar) on aging parameters of mouse hippocampus and retina.

Eight month old C57BL6 mice were exposed (head only) to 0.5 rad or 50 rads of Argon particles at the Lawrence Berkeley Radiation Facility, CA. Neuromotor performance was assessed monthly for six months beginning twelve weeks post-irradiation using a "string test". The decline in motor performance was dose-related and none of the animals was able to complete the task after four months of testing. Morphological changes were monitored six and twelve months post-irradiation by light and electron microscopy. The synaptic density in the CA-1 area of the hippocampus decreased six and twelve months after irradiation. The decrease after twelve months was less than after six months. The width of the outer nuclear layer (ONL) of the retina increased with increasing dose. The number of blood vessels between the ONL and the ganglion layer decreased twelve months after irradiation and this area did not show significant accumulation of age pigment.

Aging↗
PubMed1983

Streptobacillus moniliformis isolated from blood in four cases of Haverhill fever.

During February, 1983, an outbreak of an unusual febrile illness occurred in over 130 children attending a boarding school in Chelmsford, Essex. The clinical features included fever, an erythematous rash that was most prominent on the hands and feet, arthralgia, and the subsequent development of a sore throat. The nature and distribution of the rash varied considerably between patients and at different stages of illness. At first a viral aetiology was regarded as most likely. When Streptobacillus moniliformis was later isolated from the blood of 4 of the patients with moderately severe illnesses it became apparent that an outbreak of Haverhill fever had occurred at this school. The most probable source of the outbreak was raw milk, since all 4 patients had consumed raw milk at the school shortly before the onset of symptoms and there was no evidence of person-to-person spread of infection.

Adolescent↗
PubMed1983

Pharmacology of the human iris: development and use of challenge strategies in the study of antidepression response.

Basic physiological and neurochemical control mechanisms of human iris musculature are reviewed. The advantages and limitations of using pupillary responses to cholinergic and adrenergic drug challenges as peripheral indices of neuronal receptor sensitivity, are examined. A group of 15 depressed patients were tested with ocular instillation of pilocarpine and phenylephrine before and during treatment with Tranylcypromine. No change of pilocarpine sensitivity was found. A significant enhancement of phenylephrine sensitivity during weeks 3-5, but not during the first or second week of treatment was noted. The above potentiation of alpha-adrenergic responsiveness was correlated with clinical recovery.

Depressive Disorder↗
PubMed1983

Long-term effects of treatment in a pre-school day centre: a controlled study.

A five-year follow-up of 25 children who attended a psychiatric day centre for pre-school children is described. This group was compared at eight years of age with two matched control groups who had not received intensive treatment. There were few differences between the treated and untreated groups. Possible reasons for the findings are discussed and some methodological issues involved in carrying out evaluation studies are raised.

Attitude↗
PubMed1983

Response of the seminiferous epithelium of the mouse exposed to low dose high energy (HZE) and electromagnetic radiation.

This study was undertaken to observe the response of a rapidly dividing cell population (spermatogonial) to Helium and Argon ions as compared to x-rays. Low doses (below 100 rads) were used to more nearly simulate radiation encountered during space missions. The methods used proved compatible for both light and electron microscope studies. The average relative biological effectiveness (RBE) for Helium ions is 1, while Argon is twice as effective in killing spermatogonial cells. Part of this mixed population of cells exhibits a higher sensitivity to radiation below 15 rads. Quantitation of the radiation effects by counting the necrotic cells is not feasible because of their rapid removal, therefore all measurements were done using the surviving fraction (S/So) of spermatogonial cells.

Animals↗
PubMed1982

Temperament: a consideration of concepts and methods.

This paper discusses conceptual issues and begins with a consideration of definitions of temperament. It is suggested that the purposes for which temperament has been studied have, to some degree, dictated methods used and inferences drawn. Those psychopathologists interested in the relationship between temperament and psychiatric disorder, or emotional and behavioural disturbance, have tended to use different methods from those more concerned with delineating the structure of personality. Some issues and problems are common to both approaches, e.g. the definition of behaviour reflecting temperament in terms of style rather than content. Other issues, such as the difficulty involved in drawing a clear distinction between temperamental attributes and mental disorders, are restricted to one approach. The relative contribution of gentic and environmental effects is of interest to both psychopathologists (who wish to examine this issue in relation to the development of the individual), and to psychologists (who are usually more concerned with populations or aggregate effects). The application of biometric genetic models might clarify this issue, and various suggestions are made regarding steps that need to be taken if such models are to be successfully applied.

Biometry↗
PubMed1980

Short-term inpatient care and readmission rates: the CMHC approach versus the private approach.

Community mental health centers hospitalize patients for a significantly shorter time than do private psychiatric hospitals. Proponents of the private system of care assert that the shorter hospitalization contributes to an increased probability of readmission. A comparison of the readmission experience of CMHC patients and private patients who were hospitalized at the same institution showed no significant differences in the short-term recidivism rate. It is suggested that an aftercare network that is closely integrated with hospital care is a necessary supplement to brief hospitalization. In addition, it appears that restrictive reimbursement policies for outpatient care result in an increase in the duration of hospitalization and in the probability of rehospitalization.

Aftercare↗
PubMed1980

A study of private hearing aid users in London.

A pilot study of 40 hearing aid users sampled directly from private hearing aid dispensers' records is described. Some comparisons are made between this sample and (a) 37 private hearing aid users who had sought help from the RNID Hearing Aid Advisory Service, and (b) 58 NHS hearing aid clinic patients who also possessed a private hearing aid. The main objective was to discover people's reasons for buying a hearing aid rather than obtaining one free of charge from the NHS. The reasons given were found to be mainly those of range of design and choice of hearing aids in addition to some advantages in the type of service offered by private hearing aid dispensers.

Adolescent↗