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Biomedical subjects

M L Harris

Publications and source records attributed to M L Harris.

16 recordsLinked to original sources
PubMed1992

Increased interleukin-2 messenger RNA in the intestinal mucosal lesions of Crohn's disease but not ulcerative colitis.

Crohn's disease (CD) is characterized by granulomatous inflammation of the intestinal mucosa, but the etiology and pathogenesis of the inflammatory lesions are unknown. The aim of this study was to determine whether T-cell activation and lymphokine production occurs in the mucosal lesions of this disease. Total cellular RNA was isolated from peripheral blood lymphocytes and from colonoscopic mucosal biopsies of normal individuals and patients with CD of the colon or ulcerative colitis (UC). Levels of interleukin-2 (IL-2) messenger RNA (mRNA) transcripts in samples were determined using a quantitative reverse transcriptase polymerase chain reaction method. IL-2 mRNA transcripts were detected in histologically normal intestinal mucosal biopsies obtained from control subjects. In CD, higher levels of IL-2 mRNA transcripts were detected in the mucosa from areas of active inflammation, but in areas that were histologically normal, levels were similar to control subjects. The levels of IL-2 mRNA transcripts in biopsies from active and inactive UC were similar to control subjects. Levels of IL-2 mRNA in peripheral blood lymphocytes were low and not significantly different in all groups of subjects. In conclusion, the normal intestinal mucosa contains IL-2 mRNA transcripts and may be an important source of IL-2. Furthermore, the inflammatory lesions of CD, but not UC, have higher levels of IL-2 mRNA transcripts, suggesting that T-cell activation and lymphokine secretion in the intestine may be important in the pathogenesis of CD. These data provide further evidence that the pathogenesis of CD and UC are different.

Base Sequence↗
PubMed1992

Free radicals and other reactive oxygen metabolites in inflammatory bowel disease: cause, consequence or epiphenomenon?

Oxygen-derived free radicals and other reactive oxygen metabolites have emerged as a common pathway of tissue injury in a wide variety of otherwise disparate disease processes. This has given rise to the hope that efforts directed towards the pharmacologic control of free radical-mediated tissue injury (Reilly, P.M., Schiller, H. J. and Bulkley, G. B. (1991) Pharmacologic approach to tissue injury mediated by free radicals and other reactive oxygen metabolites. Am. J. Surg. 161: 488-503) may have particular application to patients suffering from Crohn's disease and/or ulcerative colitis. However, because tissue injury by any mechanism, even direct mechanical trauma, can elicit an inflammatory response which entails the secondary generation of toxic oxidants by neutrophils and tissue macrophages, it is important that the evidence for this association be examined critically, so as to discriminate the possibility of an etiologic role for these toxic compounds from their presence as a reflection of injury caused primarily by other agents. Similarly, in considering the therapeutic potential of free radical ablation for the treatment of patients with IBD it is important to distinguish between interventions that might specifically block the fundamental injury mechanism from those which would act in a more nonspecific, anti-inflammatory role.

Animals↗
PubMed1992

Changes in light scatter and width measurements from the human lens cortex with age.

Light scatter and width measurements of the anterior cortical layers of the human lens were made in 50 eyes of 50 subjects using computerised linear scanning densitometry of Scheimpflug images. It was demonstrated that the amount of light scatter increased with age in all of the three major zones and that zone C3 showed the most marked increase. Most lens growth occurs in zone C2 with C3 showing little increase in width once it has become established. Zone C1 showed a tendency to decrease in width with age. In addition it was shown that the C3 zone, which is not present at birth and during early childhood, appears as a distinct layer during the second decade of life. Its scattering properties continue to increase throughout life, exceeding all other zones after approximately 30 years of age, in the absence of cataract. Possible explanations for the lens zone pattern are discussed.

Adolescent↗
PubMed1992

Capsular 'pits' in the human lens.

The lens capsule is an atypical basement membrane surrounding the lens epithelial cells and lens fibres which make up the remainder of the human lens. A seemingly unreported morphological change visible in the lens capsule with the biomicroscope is described.

Coronary Disease↗
PubMed1992

The stressfulness of separation among nine-month-old infants: effects of social context variables and infant temperament.

This manuscript reports on the results of 2 experiments dealing with behavioral and adrenocortical responses to separation among 9-month-old human infants. In both experiments the social context of separation was manipulated. The results of Experiment 1 yielded evidence of a statistically significant adrenocortical response to 30 min of separation under conditions in which the substitute caregiver responded sensitivity to infant distress, but was busy and relatively noninteractive when babies were not distressed during the separation period. Altering the behavior of the substitute caregiver such that she was warm, responsive, and interactive throughout the separation produced a significant reduction in adrenocortical activity and in negative affect. In fact, these measures were not significantly different than those obtained when the mother and infant remained together in the playroom (No Separation). In Experiment 2, the effects of group versus singleton care were examined using the less stressful mode of substitute caregiving as described above. No significant condition differences in behavioral distress or cortisol were found. Furthermore, neither condition elicited a significant increase in cortisol over basal levels. Finally, these data provide evidence that maternal reports of infant Distress to Limits temperament, using Rothbart's Infant Behavior Questionnaire, predict adrenocortical responses to separation, while reports of Fear of Novelty do not.

Adrenal Cortex↗
PubMed1991

Inter and intra observer reproducibility of the new Oxford CCD Scheimpflug camera.

Scheimpflug photography is a well recognised technique for obtaining sagittal views of the anterior structures of the human eye in vivo. A new generation of Scheimpflug camera, which uses a CCD (charge coupled device) instead of film, permitting the digitised image achieved to be directly analysed using computerised linear scanning densitometry, is described. The advantages and present limitations of this system over the older film using system are discussed and the reproducibility of the new CCD system in its ability to measure certain features of the crystalline lens is presented.

Anthropometry↗
PubMed1991

Definition of normal macular thresholds on the Dicon AP2000 autoperimeter.

This paper presents the results of a study into the normal macular threshold measured by automated perimetry. The effect of age upon this parameter is demonstrated in a normal clinic population. A comparison is made with other age dependent tests of visual function and the clinical importance of the findings is discussed.

Adult↗
PubMed1990

Inflammatory bowel disease and irritable bowel syndrome.

The irritable bowel syndrome accounts for 30 to 50 per cent of patients cared for by gastroenterology practices. Irritable bowel syndrome is more common than inflammatory bowel disease. Therefore, it should not be surprising that some patients with inflammatory bowel disease are initially told that they have irritable bowel syndrome before a diagnosis of inflammatory bowel disease is firmly established. This article contends that many people have both irritable bowel syndrome and inflammatory bowel disease.

Caffeine↗
PubMed1989

Intravitreal ganciclovir in CMV retinitis: case report.

A case is reported of a 35-year-old male with established acquired immune deficiency syndrome who developed cytomegalovirus retinitis. When intravenous treatment with ganciclovir had to be withdrawn because of toxicity, one eye was treated successfully by intravitreal injections of the drug. After 15 weeks of intravitreal treatment this eye developed endophthalmitis.

Acquired Immunodeficiency Syndrome↗
PubMed1969

Flexibility.

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Adolescent↗