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Biomedical subjects

J Jackson

Publications and source records attributed to J Jackson.

At least 271 records · Page 15Linked to original sources

Effect of different corticosteroid regimens on hypothalamic-pituitary-adrenal axis and growth in juvenile chronic arthritis.

Linear growth was recorded in 36 children with juvenile chronic arthritis. In 20, the hypothalamic-pituitary-adrenal axis (HPA axis) was assessed by insulin-induced hypoglycaemia, the results of which correlated well with resting cortisol levels. Three groups were identified according to type of corticosteroid regimen administered. Group 1 (6 children), receiving daily corticosteroid therapy, were clearly suppressed and failing to grow. Group 2 (13 children) had received an alternate-day regimen from the initiation of corticosteroid therapy; they were not suppressed and growth was satisfactory in 11. Group 3 (17 children) were receiving alternate-day therapy, but had had daily corticosteroid in the past; they showed no clear pattern of suppression or growth. Factors influencing the recovery of the HPA axis and resumption of growth were assessed. No difference was found in the individual growth of 7 children who commenced alternate-day therapy before the age of 5, compared with matched controls. It is suggested that daily divided doses of corticosteroid should not be used. Ideally, a single morning dose (up to 2 mg/kg) alternate-day regimen should be employed, as this regimen has minimal effects on HPA function and growth, even in young children. For very severe systemic features, it may be necessary to add a small single dose on the alternate day.

Adolescent↗

Chemical renal medullectomy: effect on blood pressure in normal rats.

The renal medulla may have a vasodepressor function in blood pressure control. We have studied the effect of selective ablation of the medulla produced with 2-bromoethylamine hydrobromide on blood pressure in the rat. Increasing doses of bromoethylamine produced a corresponding degree of histological damage. Five weeks after medullary ablation intra-arterial blood pressure was elevated only in those groups of animals which had confluent necrosis of the papilla. The degree of hypertension was not related to plasma renin concentration but showed a significant correlation with urinary prostaglandin E2 excretion. Hypertension in medullectomized animals is probably due to a loss of a medullary vasodepressor function.

Animals↗

Corneal transparency changes resulting from osmotic stress.

Corneal thickness and transparency changes were measured following exposure of the cornea to various levels of osmotic stress. Bathing the cornea in hypotonic solutions of NaCl caused an increase in corneal thickness and light scatter within the cornea. Transparency changes with hypotonicity were determined by comparing the relative brightness of haloes around a bright lamp source for the various concentrations of NaCl solutions. Corresponding corneal thickness changes were determined by pachometry. A nearly linear relationship was found between solution hypotonicity and the degree of corneal swelling, whilst an exponential relationship was found between hypotonicity and relative halo brightness. The rate of corneal recovery from osmotic stress was found to be constant with different degrees of tonicity, although the rate of thickness recovery was much slower than the recovery from haloes.

Cornea↗

The Women's Centre in Jamaica: an innovative project for adolescent mothers.

In 1978 the Jamaican Women's Bureau established the Women's Centre, the first project in the developing world to help pregnant teenagers avoid the usual hardships of poverty and dependence. The women take courses in academic subjects and prenatal and postnatal health, and receive good medical care. Fathers and parents are involved in counseling sessions where practical life skills, including family planning, are emphasized. The young mothers improve dramatically in self-confidence, self-esteem, and in their ability to take care of their babies. The Centre's success has helped to loosen the policies of the Jamaican government on the education of pregnant school-age women.

Adolescent↗

The effects of phonetic context and linguistic complexity on /s/ misarticulation in children.

The present investigation was designed to examine the effects of phonetic context and linguistic complexity level on /s/ misarticulations in children. The subjects were normal children who misarticulated the /s/ phoneme interdentally in all positions of words. The stimuli were 48 sound-in-context initiative sequences which contained one /s/ phoneme embedded in a C1SC2 frame with all permutations of the phonemes /k,t,n,p/ in the C1 and C2 positions. The 48 sequences were composed of two basic linguistic complexity levels. The simple level consisted of the C1SC2 frame occurring in 16 noun phrases and in the more complex linguistic level seven-word sentences contained the C1SC2 frames in the subject-noun-phrase and object-noun-phrase positions. All presentations of complexity levels were counterbalanced over the three trials for a total of 144 /s/ productions for each child. Results demonstrated that certain phonemes were more facilitory for correct /s/ production than other phonemes. The analysis revealed no position effect. The mean percent correct /s/ productions over three trials did not differ significantly; however, the mean percent correct /s/ productions did vary significantly with linguistic complexity levels by position.

Articulation Disorders↗

Prevalence of asbestos related lung disease among employees in non-asbestos industries.

Employees from two non-asbestos industries wee examined to assess the prevalence of asbestos-related lung disease. Of the 214 employees, one suffered from a malignant mesothelioma of the pleura and in 13 (6.1%), pleural plaques were diagnosed radiologically. the plaques were symptomless and not associated with any disturbance in respiratory function. The sole source of asbestos fibre in one factory was the asbestos insulation surrounding steam and hot water pipes similar to that found throughout industry. Exposure occurred as the result of the way in which this insulation has been handled routinely in industry by people who have commonly been unaware either of their exposure or of its significance. In the second factory there was the possibility of additional exposure originating from a neighbouring industry that was a major consumer of asbestos. The results suggest that maintenance workers may be particularly at risk and that the presence of pleural plaques may be under-reported in the absence of a history of asbestos exposure to direct attention towards them. The presence of pleural plaques has important consequences for the individual and for others who have shared the work environment.

Adult↗

Where volunteers wear uniform.

With increasing emphasis on the role that the voluntary services can play in our hospitals and social services Jo Jackson, voluntary services co-ordinator at Whittington Hospital, thought it was time to look at and perhaps learn from the American system.

Hospital Auxiliaries↗

Toothpaste abrasive requirements to control naturally stained pellicle. The relation of cleaning power to toothpaste abrasivity.

Toothpaste abrasivity should be sufficiently high to give effective cleaning without causing mechanical damage to tooth tissue. A clinical trial carried out to measure the cleaning power of calcium carbonate toothpastes of different abrasivity is described; cleaning power is then related to in vitro dentine abrasivity measurements. These findings are used to derive an expression specifying the toothpaste cleaning power which ensures that a chosen low and cosmetically acceptable level of stain is not exceeded providing a consistent daily brushing routine is adhered to.

Calcium Carbonate↗

Recurrent systemic lupus erythematosus involving renal allografts.

Two cases of recurrent lupus erythematosus involving renal transplants are described. Neither case showed changes of transplant rejection. The clinical course, serologic tests, and renal histopathologic findings remarkably paralleled those seen during each patient's primary disease presentation. Typical and severe extrarenal manifestations of dermatitis, pleuritis, and polyarthritis were noted before renal allograft lupus involvement. Rapid renofunctional deterioration was halted in one patient by plasmapharesis. In the second patient a more protracted course involving the allograft is anticipated. Although previous experiences suggest that lupus disease activity "burns out" after the development of chronic renal failure, findings from these two cases argue against this presumption. Longer periods of transplant follow-up may show more recurrence of lupus erythematosus.

Adult↗

Altering genotype and phenotype by DNA-mediated gene transfer.

Transformation, or DNA-mediated gene transfer, permits the introduction of new genetic information into a cell and frequently results in a change in phenotype. The transforming DNA is ultimately integrated into a recipient cell chromosome. No unique chromosomal locations are apparent, different lines contain the transforming DNA on different chromosomes. Expression of transformed genes frequently results in the synthesis of new polypeptide products which restore appropriate mutant cells to the wild-type phenotype. Thus transformation provides an in vivo assay for the functional role of DNA sequence organization about specific genes. Transforming genes coding for selectable functions, such as adenine phosphoribosyltransferase or thymidine kinase, have now been isolated by utilizing transformation in concert with molecular cloning. Finally, transformation may provide a general approach to the analysis of complex heritable phenotypes by permitting the distinction between phenotypic changes without concomitant changes in DNA and functional genetic rearrangements.

Adenine Phosphoribosyltransferase↗

Induction of four proteins in chick embryo cells by sodium arsenite.

Four proteins of Mr = 89,000, 73,000, 35,000, and 27,000 are strongly induced in chick fibroblasts by sodium arsenite. Induction of these proteins is discoordinate as a function of arsenite concentration. Kinetically, all species appear 1 h after exposure to 50 microM arsenite, after 24 and 48 h of exposure, the 27,000 protein is still synthesized extensively, whereas normal cell proteins and the three other induced proteins are greatly reduced. The four proteins are unrelated by tryptic peptide-mapping procedures. Multiple subspecies of p89, p73, and p27 were observed in two-dimensional gels. The subspecies of p73 appear to be related as determined by partial proteolytic maps as are those of p27. Two-dimensional gel analysis of in vitro translation products from rabbit reticulocyte lysates primed with mRNA from uninduced and induced cells reveals that the amount of translatable mRNA specific for these proteins is increase by induction. This increase is attributable to new mRNA synthesis since actinomycin D prevent induction and new bands of RNA (Mr = 0.9 X 10(6) and 1.3 X 10(6)) appear in methyl mercury gels of oligo(dT) selected RNA from induced cells. These bands are assigned to p73 and p89 based on translation of electroeluted RNA from a similar preparative gel. A comparison is made between induction of these proteins and the heat shock response in Drosophilla melanogaster.

Animals↗

Chronic respiratory disease and respiratory function in a group of fire fighters.

A sample of 193 subjects drawn from the New South Wales Fire Brigade was studied to examine the prevalence of chronic respiratory disease and impairment of respiratory function. The prevalence of respiratory disease was less than that reported in other groups of firemen and reflects the lower level of occupational exposure, and possibly a survivor effect, within the New South Wales Fire Brigade. Among recent recruits, the effects of cigarette smoking far outweighed any contribution from occupational exposure. Among firemen with 20 years or more service a twofold increase in the prevalence of chronic bronchitis is considered to result from the additive effects of cigarette smoking and the high occupational smoke exposures consequent to the availability of respiratory protection and earlier attitudes to its use. The increasingly toxic nature of combustion products at fires was not accompanied by a discernible increase in the prevalence of chronic respiratory disease or impairment of respiratory function. The major combustion products responsible for respiratory damage were self-administered, arising from burning tobacco rather than from burning buildings.

Adult↗