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Biomedical subjects

S Gibson

Publications and source records attributed to S Gibson.

At least 145 records · Page 8Linked to original sources

Mast cell subsets in the rat distinguished immunohistochemically by their content of serine proteinases.

The specificities of antibodies raised in rabbits against rat mast cell proteinase 1 (RMCP 1) from connective tissue mast cells (CTMC), and against RMCP II from mucosal mast cells (MMC), were analysed by SDS-PAGE and Western blotting. Significant cross-reactivity was detected, and was eliminated by affinity purification and cross-absorption techniques. The resultant F(ab')2 antibodies, monospecific for each enzyme, were used for the immunohistochemical localization of RMCP I and II in rat tissues. Cells in skin, tongue, intestinal serosa and lung parenchyma which, by histochemical techniques, have been identified as CTMC, contained RMCP I exclusively. Cells in jejunal lamina propria and bronchial epithelium, previously classified as MMC, contained RMCP II. The results demonstrate the feasibility of distinguishing mast cell subsets by their content of serine proteinases.

Animals↗

Histochemical demonstration of chymotrypsin like serine esterases in mucosal mast cells in four species including man.

Serine esterases were detected in the granules of mucosal mast cells from rat, mouse, sheep, and man. Successful demonstration of enzyme activity required brief fixation (6 h) of tissues in 4% paraformaldehyde. Staining with naphthol AS-D chloroacetate produced an intense red reaction product in intraepithelial mucosal mast cells (globule leucocytes) and mucosal mast cells within the lamina propria of the gastrointestinal tract. The mast cell identity of cells stained for esterase was confirmed by sequential staining with toluidine blue (pH 0.5). Furthermore, the numbers of cells detected after staining for esterases or with toluidine blue were highly correlated. Esterase activity within mucosal mast cells/globule leucocytes from all species was inhibited with the serine enzyme inhibitor phenylmethylsulphonyl fluoride. Further histochemical studies with the substrate, N-acetyl-DL-phenylalanine B-naphthyl ester, indicated that mucosal mast cells and globule leucocytes contain esterases which are chymotrypsin like in substrate specificity.

Animals↗

Predictive value of urodynamic evaluation in newborns with myelodysplasia.

We examined 36 infants with myelodysplasia, using excretory urography, voiding cystourethrography, and urodynamic assessment in the newborn period and periodically thereafter to determine those at risk for decompensation of the urinary tract. Urodynamic evaluation showed 18 with dyssynergia of the detrusor and external sphincter, nine with synergic activity of the sphincter, and nine with no activity of the sphincter. Thirteen (72%) of the group with dyssynergia had or later were found to have hydroureteronephrosis, while this was the case in only two (22%) with synergy and one (11%) with absent activity. The conditions of these 16 patients improved after decompression by cutaneous vesicostomy or intermittent catheterization. Infants with dyssynergia of the detrusor-external sphincter are at high risk for deterioration of the urinary tract; they should be followed up closely, and intermittent catheterization should be started early.

Child, Preschool↗

The postnatal physiological and neurochemical development of peripheral sensory C fibres.

The postnatal development of sensory C fibre function was investigated in neonatal rats aged 1-21 days. From birth, flexor-withdrawal reflexes (measured from the hamstring electromyograph) to pinching and heating the skin of the hindfoot were easily recorded under light anaesthesia and in fact were exaggerated in amplitude and duration compared to adult responses. Flexor reflexes to irritant chemicals, however, were not present until day 10-11 of life. In parallel with this late development of specific chemical sensitivity, neurogenic oedema, a C fibre-mediated inflammatory reaction, also did not occur until day 11. Substance P and fluoride-resistant acid phosphatase histochemistry were used to investigate the neurochemical development of sensory C fibres. Substance P was present in the skin, nerve, dorsal root ganglion and spinal cord from birth and fluoride-resistant acid phosphate within 12 h of birth. The adult neurochemical appearance of C-fibre terminals in the dorsal horn was established in a few days. The results show that despite the apparent early anatomical and neurochemical maturity of C fibres, physiological function is not fully established until the second week of life.

Acid Phosphatase↗

The effect of 6-OHDA lesions of the nucleus accumbens septum on schedule-induced drinking, wheelrunning and corticosterone levels in the rat.

In a series of four experiments the relationship between 6-OHDA lesions of the nucleus accumbens septum (NAS), schedule-induced behaviors and plasma corticosterone levels was explored. Data from the first experiment show a significant decrease in water intake during a scheduled food delivery test hour for 6-OHDA lesioned groups of rats compared with sham or non-lesioned groups of rats, while during the remaining 23 hours of the day water intake was the same for 6-OHDA lesioned and sham lesioned groups. In a second experiment similar decreases in schedule-induced wheelrunning were observed for 6-OHDA lesioned rats when compared with sham lesioned rats. Data from a third experiment showed significant increases in plasma corticosterone levels of rats in the presence of a scheduled food delivery compared with rats given non-scheduled food. In a fourth experiment it was shown that 6-OHDA lesions of the NAS abolish this increase of corticosterone levels in rats on a food delivery schedule. These data extend the findings of Robbins and Koob [19] and show a more general involvement of the dopaminergic pathways of the NAS in schedule-induced behaviors and in concomitant plasma corticosterone changes.

Animals↗

The concept of coping.

Coping is action directed at the resolution or mitigation of a problematic situation. There are a number of ways in which this may be attempted, and a number of ways of classifying coping strategies. This paper presents a simple schema of six coping themes, ordered in terms of their defensiveness and the degree of attempted personal control which they imply. They comprise rejection, control, resignation, dependency, avoidance and minimization, and characterize the meaning or qualitative 'style' of the individual's response, rather than the formal characteristics of the strategies employed. Data from studies of breast cancer and surgical patients are cited to illustrate the substance of the themes.

Adaptation, Psychological↗

Foot shock analgesia. Lack of correlation with pituitary and plasma immunoreactive-beta-endorphin.

Effects of inescapable foot shock on pain threshold and on levels of immunoreactive beta-endorphin (ir-beta EP) in anterior pituitary, neuro-intermediate lobe and plasma were determined by hot plate test and radioimmunoassay respectively. Whereas handling and conditioned stress failed to alter baseline pain threshold, 20 min inescapable foot shock produced modest and transient analgesia. Levels of plasma ir-beta EP and corticosterone were significantly and concurrently raised by all treatments and remained elevated 40 min after foot shock. Changes in plasma levels of ir-beta EP and corticosterone were found to parallel one another but did not correlate with changes in pain threshold. AP content of ir-beta EP was significantly reduced 60 min after the cessation of inescapable foot shock, and N-IL content from 20 min after. The findings suggest that (i) plasma levels of ir-beta EP and corticosterone do not reflect changes in pain threshold, and (ii) ir-beta EP levels in anterior pituitary, neurointermediate lobe and plasma probably are not causally related to foot shock analgesia.

Analgesia↗

Blunt renal trauma: the value of a conservative approach to major injuries in clinically stable patients.

A 10-year retrospective study of 393 cases of blunt renal trauma was carried out to evaluate the use of a conservative approach to therapy in clinically stable patients with major renal injuries. Injuries were minor in 357 patients who were successfully treated conservatively. Major injuries occurred in 36 patients; 28 were treated conservatively. Of the 28, 17 had no complications. Seven required total or partial nephrectomy to control bleeding and four had drainage, one with marsupialization of a large renal cyst, 1 year after injury. The authors advocate conservative treatment of major blunt renal injuries in clinically stable patients.

Adolescent↗

Effects of capsaicin applied locally to adult peripheral nerve. II. Anatomy and enzyme and peptide chemistry of peripheral nerve and spinal cord.

(1) Capsaicin solution was applied for 15 min around a 1 cm length of sciatic nerve in the mid upper leg of adult rats. (2) Electron microscopic examinations of the nerve in the treated region after 14 days shows no signs of degeneration of either myelinated or unmyelinated fibres attributable to the capsaicin. (3) Fluoride resistant acid phosphatase FRAP disappears from the central terminals of the treated nerve by 7 days. (4) 1.5 mM capsaicin is sufficient to product a complete reduction of FRAP in the spinal cord. (5) The peptides substance P and cholecystokinin (CCK) are markedly depleted in the region of spinal cord terminations of the treated nerve at 14 days. (6) Substance P and CCk are not affected in spinal cord regions other than in the unmyelinated afferent terminal zone. Similarly neurotensin and neurophysin which are not present in afferent fibres are not influenced by capsaicin treatment of the sciatic. (7) It is concluded that there are chemical changes in the spinal cord terminals of fine afferents after local peripheral capsaicin.

Acid Phosphatase↗

A critique of the 'objectives model of curriculum design' applied to the education and training of district nurses.

In 1976 the Panel of Assessors for Nurse Training published the 'Right on the Education and Training of District Nurses SRN/RGN'. This recommends an extended form of training based on an outline curriculum. The new scheme of training will be implemented in 1981, and responsibility for developing the detailed curriculum will rest with district nurse tutors and will be undertaken at local level. One method that might be used by district nurse tutors is the 'objectives model of curriculum design', which requires educators to (a) consider sources for the derivation of objectives; (b) identify and express objectives, preferably in behavioural terms; (c) utilize the objectives to identify skills, attitudes and learning experiences required to produce desired learning outcomes and (d) evaluate whether or not objectives have been achieved. It is generally acknowledged that this particular model, which has been tested and tried in the spheres of general and vocational education, has strengths and weaknesses. Some of these are identified in this paper and applied to the education and training of district nurses. District nurse tutors might, therefore, consider both the strengths and the weaknesses of this approach as they prepare to develop the outline curriculum.

Curriculum↗

Ineffectiveness of adenine arabinoside and adenine arabinoside 5'-monophosphate in simian varicella infection.

Adenine arabinoside and adenine arabinoside 5'-monophosphate (ara-AMP) have been evaluated for antiviral activity against simian varicella virus infection in monkeys. In a preliminary study for toxicity, intramuscular injection of ara-AMP at 15 mg/kg per day as a single injection for 5 days to two normal patas monkeys caused no detectable local reaction, no weight loss or changes in serum transaminase levels, and no hematological abnormalities. When this dose was given in the treatment of four simian varicella virus-infected patas monkeys, no effect was observed on the clinical course of infection, as compared with four infected monkeys which received phosphate-buffered saline. Treatment was begun 43 h after virus inoculation and was continued for 16 days. Toxicity of intravenously administered ara-AMP at 100 to 50 mg/kg per day for 5 days to pairs of uninfected patas monkeys was evident by hematological and hepatic histological alterations, as well as the death of one monkey in each pair. No gross evidence of toxicity occurred in two monkeys which received 20 mg of ara-AMP per kg per day. The antiviral efficacy of intravenous treatment was studied in groups of four African green monkeys which received adenine arabinoside at 15 mg/kg per day or ara-AMP at 18.4 mg/kg per day. Drug administration began 48 h after inoculation with simian varicella virus and continued for 10 days. The monkeys that received treatment did not respond to infection differently from four infected control monkeys similarly treated with phosphate-buffered saline.

Animals↗