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Biomedical subjects

J Carson

Publications and source records attributed to J Carson.

At least 55 records · Page 3Linked to original sources
PubMed1995

In vivo actions of insulin-like growth factor-I (IGF-I) on brain myelination: studies of IGF-I and IGF binding protein-1 (IGFBP-1) transgenic mice.

To study the effects and mechanisms of insulin-like growth factor I (IGF-I) on brain myelination in vivo, the morphology of myelinated axons and the expression of myelin specific protein genes have been examined in transgenic (Tg) mice that overexpress IGF-I and that those ectopically express IGF binding protein-1 (IGFBP-1), a protein that inhibits IGF-I actions when present in molar excess. Our data show that the percentage of myelinated axons and the thickness of myelin sheaths are significantly increased in IGF-I Tg and decreased in the IGFBP-1 mice. Cerebral cortical proteolipid protein (PLP) and myelin basic protein (MBP) mRNAs consistently exhibit approximately 200% increases in IGF-I Tg mice and approximately 50% decreases in IGFBP-1 Tg mice. The percentage of oligodendrocytes labeled with a PLP cRNA probe in the corpus callosum and cerebral cortex also is increased in IGF-I Tg mice and reduced in IGFBP-1 Tg mice, suggesting that IGF-I promotes oligodendrocyte survival and/or proliferation. The alterations in the number of oligodendrocytes, however, can not completely account for the changes in myelin gene expression. These results strongly indicate that IGF-I increases myelination by increasing the number of myelinated axons and the thickness of myelin sheaths, the latter by mechanisms that involve stimulation of the expression of myelin protein genes and increase of oligodendrocyte number.

Animals↗
PubMed1994

Diagnostic ultrasound in pregnancy and low birthweight.

Diagnostic ultrasound has been used increasingly in obstetric practice over the past decade. To date, adverse effects of ultrasound on the fetus have not been reported, but studies have been done on small sample sizes. This study looks specifically at the association of ultrasound exposure during pregnancy and the risk of low birthweight in the offspring. A validation case-control study was also performed based on information from a sample of medical charts. With a database of more than 13,000 pregnancies, there was no indication of an adverse effect of ultrasound performed during the first two trimesters of pregnancy.

Adolescent↗
PubMed1994

Characteristics of Vagococcus salmoninarum isolated from diseased salmonid fish.

Isolates of the salmonid pathogen Vagococcus salmoninarum were recovered from Atlantic salmon, rainbow trout and brown trout with peritonitis. The phenotypes of these isolates and the type strain of Vag. salmoninarum NCFB 2777 were determined by morphological, biochemical and physiological tests and whole cell protein profiles by SDS-PAGE. There was a high level of phenetic similarity between the salmonid isolates and the type strain. The species forms short Gram-positive rods, hydrolyses L-pyrrolidonyl-beta-naphthylamide, is alpha-haemolytic on sheep's blood agar, grows at pH 9.6 and 10 degrees C but not at 40 degrees C or in 6.5% NaCl and is catalase-negative; a Lancefield group N antigen is not present. Vagococcus salmoninarum can be distinguished phenetically from similar fish pathogens including Carnobacterium piscicola, Enterococcus seriolicida and Lactococcus piscium.

Animals↗
PubMed1994

Occupational stress amongst care staff working in nursing homes: an empirical investigation.

A questionnaire survey of care staff in nursing homes examined staff stress. Staff completed questionnaires covering Type A behaviour, job satisfaction, psychological well-being, relaxation behaviour, coping skills and demographic details. A specific measure of nursing home stress was developed following a pilot study. From a total sample of 375, 112 (30%) responses were obtained. On the stress questionnaire the major stressors were found to be 'unsatisfactory wages', 'shortage of essential resources', 'not enough staff per shift', 'feeling undervalued by management', 'lifting heavy patients' and 'working with colleagues who are happy to let others do the work'. Factor analysis of stress questionnaire responses identified five major stress groupings. These were, 'differing expectations about patient care', 'management factors', 'lack of support from other staff', 'feeling inadequately trained to deal with job demands' and 'home-work conflicts'. Examination of stress outcomes showed that many staff were under pressure, with high levels of smoking and alcohol intake. Given the increasing importance of nursing home care for the elderly the present study is timely. The implications of the findings for further research, and for the training of staff in nursing homes are considered.

Adult↗
PubMed1994

Forging a future for nursing. A system's nurse executives collaborate to create a strategic plan.

In early 1991 the Nurse Executives' Council (NEC) of the Seattle-based Sisters of Providence Health System completed a survey assessing the effectiveness of patient care delivery processes and gauging the extent to which nurses participate in planning programs and services. Later that spring the NEC reviewed the survey and made a preliminary identification of nursing strategic issues. To complement this internal survey, in fall 1991 the council was given an overview of the external environment as it relates to nursing. The council also formed three committees--Strategic Planning/Bylaws, Human Resources, and Productivity--to address concerns that surfaced in the internal assessment survey process and to help design a document outlining the council's strategic plan for system nurses. After working with the NEC liaison, the Strategic Planning/Bylaws Committee drafted a plan for review by NEC members before submitting it for approval by appropriate bodies within the organization. The final plan, unveiled at the fall 1992 NEC meeting, identifies four key strategic issues for nursing, including the need to: Develop nursing leadership; Maximize human resources; Coordinate client and patient care over a continuum of healthcare services; Demonstrate fiscal stewardship.

Decision Making, Organizational↗
PubMed1993

Transfusion and surgery.

In this survey of transfusion in surgery, we have attempted to provide the surgeon with an understanding of the problems associated with homologous transfusion and a practical knowledge of treatment strategies and alternatives designed to reduce homologous blood exposure. Such a review cannot be encyclopedic. Our hope is that it will serve the reader as a stimulus to examine his or her transfusion practices and as a guide for future self-learning.

Animals↗
PubMed1993

The inhibition by ionophores in vitro of an Enterococcus-like pathogen of rainbow trout, Oncorhynchus mykiss.

Streptococcosis is a major disease of several fish species in Australia, Japan and South Africa. The minimum inhibitory concentration of some ionophores (lasalocid, monensin, narasin and salinomycin) was determined in vitro for an Enterococcus-like species pathogenic for rainbow trout (Oncorhynchus mykiss) in Australia. Forty isolates of the fish pathogen were tested, together with control strains of Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212 and Streptococcus bovis ATCC 9809. The minimum inhibitory concentrations (MIC) of erythromycin, the drug of choice for controlling streptococcosis, ranged between 0.1 and 0.8 microgram/ml whereas the MIC values for the ionophores ranged between 0.2 and 1.5 micrograms/ml. Of the ionophores tested, narasin was the most inhibitory (0.2-0.4 microgram/ml), while monensin was the least inhibitory (0.4-1.5 micrograms/ml). Salinomycin was marginally more inhibitory (0.4-0.8 microgram/ml) than lasalocid (0.8 microgram/ml).

Animals↗
PubMed1993

Dupuytren's contracture in pensioners at the Royal Hospital Chelsea.

Dupuytren's disease of the hands was present in 55 (13.75%) of the 400 elderly ex-servicemen living at the Royal Hospital Chelsea. Five men (9.1%) reported the condition in either a parent or sibling, but none was aware of an affected child. The prevalence of heavy drinking, non-insulin dependent diabetes or manual occupation was statistically the same in those with or without the condition. Overall, both hands were equally affected, but they differed in severity in 29 men. In milder cases the left hand was the more severely affected (grades 1 and 2); the reverse was true when the difference in severity was greater (grade 3). Since the original description of Dupuytren's disease [1] attempts have been made to link it with a variety of other conditions. These have included trauma, alcoholism and cirrhosis, [2] epilepsy [3] and diabetes mellitus [4]. A genetic link is accepted [5]. The condition is more common in men than women and becomes increasingly common with advancing age [6]. The prevalence in elderly men has been reported as high as 28.9%, rising to 64.3% in surveys of affected families [7]. There are still many physicians who, with a knowing wink when they spot that one of their patients has a Dupuytren's contracture, mentally register that he is an alcoholic. This paper is an attempt to disprove this fairy story. It describes a survey of Dupuytren's disease in a population of elderly men drawn from all parts of the United Kingdom and Ireland.

Aged↗
PubMed1992

Patient voices.

Patients and nurses at a psychiatric hospital were asked which aspects of care they rated most highly. The results showed that the two groups had very different perceptions. Tonmoy Sharma and colleagues report their findings and the implications.

England↗
PubMed1992

Serological responses and immunity produced in salmonids by vaccination with Australian strains of Vibrio anguillarum.

The Australian populations of rainbow trout (Onchorhynchus mykiss) and Atlantic salmon (Salmo salar) were found to have similar immunological responses to local strains of Vibrio anguillarum as those reported for the more genetically diverse populations of these fish and strains of V. anguillarum found in the Northern Hemisphere. In addition, our studies more precisely defined the respective responses of rainbow trout and Atlantic salmon to immersion vaccination by the bath and dip methods.

Animals↗
PubMed1992

Freon injection injury to the hand. A report of four cases.

During a 6-month period, the poison center was consulted on three occasions for advice regarding accidental injection of hexafluorethane (Freon) used in the manufacturing process of athletic shoes. A fourth case was later identified after consulting physicians near the manufacturing facility. Little information exists in the medical literature concerning injection of freon or other volatile substances. In each of these cases, workers inadvertently injected concentrated hexafluorethane into a finger while holding the shoe component and attempting to inject hexafluorethane. Each case presented with edema, limitation of motion, and crepitation. Hand roentgenogram revealed subcutaneous gas. Treatment was nonsurgical, consisting of splinting, tetanus immunization, and antibiotics. Rapid resolution of symptoms occurred in all four cases. Hexafluorethane is relatively inert when injected and has low toxicity. However, potential rapid expansion warrants observation for pressure injury.

Accidents, Occupational↗
PubMed1992

Systemic and regional hemodynamic effects of 1,25-dihydroxyvitamin D3 administration.

OBJECTIVE: To evaluate the cardiovascular effects of 1,25-dihydroxyvitamin D3 (1,25-D). DESIGN: Recent studies suggest that Ca-regulating hormones may contribute to the genesis of hypertension. We determined systemic and regional hemodynamics 24 h after administration of 1,25-D or vehicle to normal conscious Sprague-Dawley rats. In addition, to dissociate the vascular effects of 1,25-D from changes in serum ionized Ca2+, 1,25-D and vehicle were administered to rats maintained for 3 days on a low-Ca diet. To evaluate the effect of the slight rise in serum ionized Ca2+ with 1,25-D administration, we infused CaCl or vehicle over 1 h into normal rats to raise the serum Ca2+ to near that of rats treated with 1,25-D. METHODS: The radioactive microsphere technique was used. RESULTS: Systemic hemodynamics (blood pressure, heart rate, cardiac output, total peripheral resistance and stroke volume) did not differ between the two groups receiving a normal-Ca diet. In these rats 1,25-D significantly decreased renal blood flow (RBF), increased renal vascular resistance (RVR) and slightly increased serum ionized Ca2+. Similarly, in rats receiving a low-Ca diet, 1,25-D administration decreased renal blood flow, increased renal vascular resistance and caused only a minimal increase in serum ionized Ca2+. A low-Ca diet also increased heart rate, cardiac blood flow and renal blood flow. Although CaCl infusion raised serum ionized Ca2+, blood pressure, renal blood flow and renal vascular resistance did not change significantly. CONCLUSION: 1,25-D may constrict the renal vasculature directly or indirectly by enhancing the vascular sensitivity to circulating vasoconstrictors.

Animals↗
PubMed1991

Decreased spinal cord content of calcitonin gene-related peptide in the spontaneously hypertensive rat.

Calcitonin gene-related peptide (CGRP), produced by alternative processing of the primary transcript of the calcitonin gene, is a potent vasodilator. We have shown that dietary calcium deficiency accompanied by decreased serum ionized calcium significantly decreases the neuronal content of CGRP in laminae I and II of the dorsal horn of the spinal cord in the growing rat. The spontaneously hypertensive rat (SHR) is characterized by decreased serum ionized calcium levels and is thought to most closely resemble human essential hypertension. To determine if the neuronal content of CGRP is decreased in the SHR compared to the Wistar-Kyoto (WKY) parent strain, CGRP was localized immunocytochemically in the dorsal horn of the spinal cord. The density of immunocytochemical staining was quantitated by computer-assisted image processing of laminae I and II of the upper thoracic spinal cord of 12-14 week old male SHR (n = 4) and WKY (n = 4) normotensive, control rats. The SHR had significantly decreased neuronal CGRP content compared to the WKY rats (107 +/- 5 vs 121 +/- 6 arbitrary units, P less than 0.01). In contrast, the neuronal density of substance P (SP), which frequently co-exists with CGRP in this neuronal population, was not different between the two groups (SHR, 91 +/- 6 (n = 4) vs WKY, 88 +/- 3 arbitrary units (n = 4)).

Animals↗
PubMed1991

A case of insect borne tularemia above the tree line.

A case of insect borne transmission of ulceroglandular tularemia in Canada above the tree line is presented. It seems likely from the available entomological data that a mosquito was the vector in this case. Mosquito vectors may be important in inducing the high seroprevalence of antibodies to F. tularensis above the treeline. This case is presented to make clinicians aware of the possibility of tularemia in cases of insect borne ulceroglandular disease in the arctic and, the necessity of measuring tularemia agglutinins in these patients. It should be noted that isolation of this organism poses a risk to laboratory personnel, and therefore should only be attempted in a reference laboratory. Therefore the diagnosis is based upon the finding, in the appropriate clinical context, of a four-fold rise in the tularemia agglutinins, or a single convalescent titre of 1:160 or greater.

Adolescent↗