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Biomedical subjects

R L Jack

Publications and source records attributed to R L Jack.

At least 19 recordsLinked to original sources
PubMed2000

TatD is a cytoplasmic protein with DNase activity. No requirement for TatD family proteins in sec-independent protein export.

The Escherichia coli Tat system mediates Sec-independent export of protein precursors bearing twin arginine signal peptides. Genes known to be involved in this process include tatA, tatB, and tatC that form an operon with a fourth gene, tatD. The tatD gene product has two homologues in E. coli coded by the unlinked ycfH and yjjV genes. An E. coli strain with in-frame chromosomal deletions in all three of tatD, ycfH, and yjjV exhibits no significant defect in the cellular location of five cofactor-containing enzymes that are synthesized with twin arginine signal peptides. Neither these mutations nor overproduction of the TatD protein cause any discernible effect on the export kinetics of an additional E. coli Tat pathway substrate. It is concluded that proteins of the TatD family have no obligate involvement in protein export by the Tat system. TatD is shown to be a cytoplasmic protein. TatD binds to immobilized Ni(2+) or Zn(2+) affinity columns and exhibits magnesium-dependent DNase activity. Features of the tatA operon that may control TatD expression are discussed.

Biological Transport↗
PubMed1991

The role of attributions in self-poisoning.

Sixty patients who had taken an overdose of drugs within the previous 24 hours completed the Attributional Style Questionnaire and the Profile of Mood States scale. Their scores were compared with two age-matched samples: 31 medical patients and 71 non-patient controls. Overdose patients had significantly higher stable and global attributions for negative events than controls, but were no different in attribution for positive events. They were also more disturbed in their mood, but their level of mood disturbance did not correlate with levels of attribution. Thirty-two of the overdose group were followed up one week later, by which time there had been a reliable downward shift in mood. However, there was no corresponding reliable shift in attributions, which remained significantly higher than normal. These results suggest that attributions may be important in determining how self-poisoners cope with life-events, but the relationship with mood is complex; attributions are not simply mood-dependent, nor is mood level or recovery simply attribution-dependent.

Adult↗
PubMed1991

Attribution and intervention in self-poisoning.

This paper discusses factors which have affected progress in the primary and secondary prevention of suicidal behaviour. An attributional model of helping and coping described by Brickman and his colleagues (1982) is used to suggest that the match or mismatch between attitudes and attributions of helpers and helped is critical in determining (a) whether or not people seek help when in a crisis, and (b) whether or not people respond to help when they receive it. The evidence for the efficacy of cognitive-behavioural problem-solving therapies is reviewed in the light of their ability to take account of matches or mismatches in attitudes towards helping and being helped.

Adaptation, Psychological↗
PubMed1986

Q-switched neodymium: YAG laser surgery of the vitreous.

Fifty-nine eyes underwent vitreous surgery (vitreolysis) with the Q-switched Nd: YAG laser. This was used to cut vitreoretinal bands and membranes in 16 eyes and to clear persistent vitreous opacities in 25 eyes. The use of appropriate specialized contact lenses and modification of the standard slit-lamp delivery system were essential for vitreous YAG laser surgery. Successful results occurred in eyes where the target tissues were located at distances greater than 2 mm from the crystalline lens and the retina. Vision was improved in 18 eyes, unchanged in 40 eyes, and worse in 1. Complications included focal opacities of the crystalline lens in 5 eyes, retinal holes with detachment in 1 eye, and minor retinal hemorrhages in 4. Methods of preventing complications are discussed.

Cataract↗
PubMed1983

Prediction of outcome in psychogeriatric patients.

A 1-year follow-up study was carried out of the 212 patients aged 65 and over admitted to Fulbourn Hospital in 1980. Outcome was uniformly poor for patients with dementia and better but more variable in those with functional illnesses. No social or demographic variables were significantly associated with outcome in the demented group but age, female sex, previous admission and independent accommodation prior to admission were significantly associated with good outcome in those with functional illnesses. A predictive index was constructed relating social variables on admission to 1-year outcome.

Aged↗
PubMed1978

Choroidal Osteoma.

Choroidal osteomas caused visual symptoms in four healthy young women. A positive 32P test led to enucleation and histopathologic confirmation of the diagnosis in one patient. The characteristic ophthalmoscopic findings in these patients included the following: (1) slightly and irregularly elevated, yellow-white, juxtapapillary, choroidal tumor and well-defined geographic borders; (2) diffuse and mottled depigmentation of the overlying pigment epithelium; and (3) multiple small vascular networks on the tumor surface. A diffuse mottled pattern of hyperfluorescence in the area of the tumor occurred during the early and later stages of angiography. The tumors were ultrasonically dense, and the orbital tissue behind them was rendered silent. The tumors were visible on routine orbital x-ray films and computerized tomograms. The latter study demonstrated the tumors as having the consistency of normal bone.

Adult↗
PubMed1978

Peripapillary disciform degeneration of the retina: diagnosis and treatment.

Peripapillary disciform detachments are infrequent disorders of the ocular fundus. They may occur in patients of all age groups and result from a number of different causes. It is important to suspect this potentially treatable diagnosis when a patient presents with visual loss and a rounded, oval, or tongue-like mass extending from the optic nervehead in any meridian. Accurate diagnosis depends on intravenous fluorescein angiography. The subretinal neovascular net extending from the optic nervehead peripherally can be demonstrated only with angiography. Treatment of peripapillary disciform macular degenerations with photocoagulation is often successful, but is difficult due to their location. With inadequate treatment, the subretinal neovascular membrane may continue to spread and proliferate, and with excessive treatment, there may be damage to the papillomacular nerve fiber bundle, with permanent loss of central vision. It is most important to carry out close postoperative patient follow-up and retreatment when indicated once treatment has been initiated.

Adolescent↗
PubMed1976

Techniques of argon laser photocoagulation of diabetic disk new vessels.

Four argon laser techniques have been evaluated in the eradication of diabetic disk neovascularization: focal (nonfeeder) photocoagulation, feeder-frond photocoagulation alone, panretinal photocoagulation alone, and feeder-frond treatment combined with panretinal photocoagulation. Focal photocoagulation was dangerous and the least effective technique in preventing recurrence of neovascularization. Feeder-frond photocoagulation was effective initially, but was associated with a high incidence of recurrent neovascularization. Panretinal photocoagulation and panretinal photocoagulation combined with feeder-frond treatment produced results superior to those obtained with the two earlier techniques. The best results were obtained with combined feeder-frond and panretinal photocoagulation done concurrently. Early diagnosis, aggressive photocoagulation therapy, and close follow-up were essential in order to obtain good results.

Adolescent↗
PubMed1976

B-scan ultrasonography of the retina and vitreous.

We feel that ultrasonography performed prior to vitreous surgery should be performed or at least observed by the operating surgeon or the assistant. The actual dynamic scanning process allows much more information about the status of the eye than looking at static pictures. Although vitreous surgery can be performed without preoperative ultrasonographic examination, we feel that ultrasonography can provide the surgeon with valuable, accurate information about the status of the vitreous humor and the retina.

Eye Diseases↗