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Biomedical subjects

M Dunn

Publications and source records attributed to M Dunn.

At least 19 recordsLinked to original sources
PubMed1992

Antisense-mediated specific inhibition of P120 protein expression prevents G1- to S-phase transition.

A pentadecadeoxyribonucleotide (5'-AAAGCCCCCCACCAC), complementary to a splice junction site of mRNA for human proliferation-associated nucleolar protein P120, inhibited expression of the P120 gene and the mitogen-induced proliferation of human lymphocytes. The inhibition of P120 gene expression and proliferation was concentration dependent and reached 90% at 200 microM, as measured by [3H]thymidine uptake and by densitometric scanning of Northern (mRNA) and Western (protein) blots of P120. Inhibition was not observed in cells treated with the correspondent nonsense oligomer. P120 antisense oligomer treatment prevented S-phase entry of mitogen-stimulated lymphocytes, as determined by flow cytometric analysis, but did not block G0-G1 transition assessed by morphological blast transformation and induction of [3H]uridine incorporation. Results of this study suggest that P120 expression may be required for the upregulation of nucleolar function necessary for cell proliferation.

Base Sequence↗
PubMed1992

Latex agglutination testing directly from throat swabs for rapid detection of beta-hemolytic streptococci from Lancefield serogroup C.

A latex agglutination method for the rapid detection of beta-hemolytic streptococci from Lancefield serogroup C in throat swabs from 403 university students with symptomatic pharyngitis was evaluated. Compared with culture, the rapid test was poorly sensitive (34.4%) but very specific (98.4%) in detecting group C beta-hemolytic streptococci. The sensitivity of the rapid test improved with an increasing quantity of growth on culture.

Adolescent↗
PubMed1992

Pulmonary embolism in younger adults.

To test the hypothesis that the clinical presentation and outcomes are different when pulmonary embolism occurs in younger (age 18 to 40 years) as compared to older (age greater than 40 years) adults, 40 younger patients were compared with older patients. No risk factors could be identified in 28 percent of the younger group. Normal physical examinations were more common (58 vs 28 percent, p = 0.01) among younger as compared with older adults. Hypoxemia was absent in 29 percent of the younger and 3 percent of the older group (p = 0.004); P(A-a)O2 was significantly lower among younger patients even after controlling for age. Mortality was decreased sevenfold (2.5 vs 18 percent, p = 0.03) among younger patients. These data indicate that pulmonary embolism tends to have a subtle presentation in younger adults. When diagnosed and treated, the mortality rate is substantially less among younger as compared with older patients.

Adolescent↗
PubMed1992

Anticoagulant treatment of atrial fibrillation in the elderly.

There is now adequate clinical evidence that the most appropriate treatment of elderly patients with non-valvular atrial fibrillation is with low dose warfarin. Patients may have contraindications to therapy with this agent, but should not be denied treatment based on age alone. Withholding treatment based on age places patients at unwarranted risk for severely disabling thromboembolic complications.

Aged↗
PubMed1991

Effects of endothelin on cultured human and rat glomerular mesangial cells.

Figure 5 summarizes our results and the data in the literature with regard to both short-term signalling and long-term signalling induced by endothelin. Short-term signalling, which induces vasoconstriction, is undoubtedly mediated by multiple signals including increments of cytosolic calcium, stimulation of protein kinase C and alkalinization of the cytosol. Endothelin also activates negative feedback pathways including arachidonate release with the synthesis of vasorelaxant prostaglandins and potentiation, in a prostaglandin-dependent manner, of beta-adrenergic-stimulated adenylate cyclase. Long-term signalling is less well understood and may depend not only on phospholipase activation with subsequent changes of calcium and protein kinase C but also stimulation of other protein kinases which phosphorylate key intermediates. Endothelin stimulates the transient appearance of protooncogenes that might play a role in the induction of cellular proliferation.

Animals↗
PubMed1979

Simultaneous bilateral retinal arterial occlusions treated by exchange transfusions.

Bilateral retinal vascular occlusions occurred simultaneously in a 25-year-old man. They were treated by exchange transfusions. After the transfusions, the patency of the previously occluded vessels was reestablished. Subsequently, the patient recovered good central vision. It is interesting to speculate how exchange transfusions, used during the past few years for treatment of life-threatening situations, may be useful for the treatment of retinal arterial occlusions in patients with sickle cell disease.

Adult↗
PubMed1979

Sensitivity and specificity of echocardiography in the assessment of valve calcification in mitral stenosis.

Eighty-seven patients (64 females and 23 males) with mitral stenosis were studied by M-mode echocardiography to assess the sensitivity and the specificity of the echocardiographic technique in the identification of valve calcification. The mitral valves were examined at operation, and the amounts of calcium were graded as heavy, light, or absent. We compared this with the amount of calcification assessed by radiographic, previously accepted echocardiographic, and newly derived echocardiographic criteria. In identifying the presence or absence of valve calcification, radiography was the least sensitive (53.7 per cent), but the most specific (90.9 per cent) technique, and has the highest predictive accuracy (90.6 per cent). Previously accepted echocardiographic criteria had the highest sensitivity (92.6 per cent), but the lowest specificity (12.1 per cent), and the lowest predictive accuracy (63.3 per cent). The newly derived echocardiographic parameter MT/ST (ratio between the maximal thickness of the left ventricular margin of the interventricular septum) was both sensitive (75.9 per cent) and specific (81.8 per cent) and also had a predictive accuracy (87.2 per cent) similar to that of radiographic techniques. The MT/ST ratio is demonstrated to be the most useful non-invasive method for assessing valve calcification in mitral stenosis.

Adolescent↗
PubMed1979

The risk of pericardiocentesis.

The risk and potential risk factors of pericardiocentesis were assessed by a review of a series of 52 pericardiocenteses comprising all those performed in the cardiac catheterization laboratory of one institution from 1971 to 1978. On the basis of the operative results, the patients were separated into two groups for comparison; Group I comprised all patients with a successful uncomplicated (35) pericardiocentesis and Group II all those with a nonproductive (16), nontherapeutic (1) or complicated (8) pericardiocentesis. Complications consisted of one death, one cardiac arrest, one aspiration of a subdiaphragmatic abscess and five ventricular punctures without adverse sequelae. Among the patients who had a nonproductive pericardiocentesis, the condition of 11 had probably been misdiagnosed but at least 4 had a false negative pericardiocentesis. Comparison of the two groups showed no significant difference in the incidence of cardiac tamponade or in the clinical presentation based on historical, physical, electrocardiographic, roentgenographic or echocardiographic findings of pericardial disease. Pericardiocentesis was usually successful when performed for suspected malignant pericardial effusion but often unsuccessful when performed for suspected hemopericardium. Anatomically, all patients in Group II had either minimal or loculated posterior pericardial effusion. It is concluded that pericardiocentesis can be performed at a low risk that can be further minimized by consideration of the disease process and the anatomic location of the pericardial fluid.

Adolescent↗
PubMed1979

The early results of treatment of stricture of the male urethra using the Sachse optical urethrotome.

Thirty-nine male patients with urethral stricture have undergone urethrotomy using the Sachse optical urethrotome. Post-operatively a urethral catheter was used for 24 to 72 h. The technique is simple, the stay in hospital is short and complications are uncommon. Eighty-two per cent of the patients are now symptom-free and further 13% are sufficiently improved to be able to void satisfactorily at follow-up varying from 4 months to 2 1/2 years (mean 12 months). The 2 patients in whom unsatisfactory results were obtained had long strictures. We feel that direct vision urethrotomy should be considered as a treatment for urethral stricture.

Adolescent↗
PubMed1979

Balanitis xerotica obliterans.

Twenty patients with histologically proven balantis xerotica obliterans have undergone different forms of treatment; their progress has been reviewed and discussed. Balanitis xerotica obliterans involving only the foreskin was best treated by circumcision. The patients in whom meatal stenosis was present responded well to regular meatal dilatation, meatotomy followed by regular dilatation and, in advanced cases, to meatoplasty. At present there is no evidence to indicate that associated urethral strictures, proximal to the fossa navicularis, are due to balanitis xerotica obliterans.

Adolescent↗
PubMed1979

The long-term results of ileal conduit urinary diversion in children.

Sixty-seven children undergoing urinary diversion by ileal conduit tolerated this procedure well. The initial results were most satisfying, but late complications occurred in 55 children (82%), and this is a cause for concern. Even when the surgical complications were avoided, it seemed important to consider carefully the psychological problems that these children with ileal loop diversion could develop as they advanced into adult life.

Adolescent↗
PubMed1979

Hibitane bladder irrigation in the prevention of catheter-associated urinary infection.

The effect of regular chlorhexidine bladder irrigations on catheter-induced urinary infection in patients admitted as urological emergencies was investigated. Excluding patients infected on admission the urine remained sterile throughout the period of catheterisation in 52% of those receiving chlorhexidine but in only 26% of a control group of patients.

Aged↗
PubMed1979

Vesicoplication in the management of chronic urinary retention.

Eighteen patients have been treated by vesicoplication for low tension chronic urinary retention. The clinical presentation, operative technique and results in these 18 patients are discussed. Vesicoplication is shown to be a simple, safe and effective method of relieving symptoms in this group of patients.

Chronic Disease↗
PubMed1979

The role of selective internal urethrotomy in the management of urethral stricture: a multi-centre evaluation.

The advent of selective internal urethrotomy under direct vision has enabled precision endoscopic surgery to be undertaken on a wide range of urethral strictures. A multi-centre survey of 197 cases involving 322 urethrotomy procedures from 5 urological departments in England is reported. The overall results after a follow-up of up to 4 years suggest that there is no indication for further procedures currently existing in 160 (81%) of those cases subjected to selective internal urethrotomy. The additional injection of triamcinalone acetate into the strictured area prior to urethrotomy is recommended in resistant cases. The procedure of selective internal urethrotomy is, in our opinion; the best primary method for the treatment of urethral stricture, and it is hoped this will reduce the indications for anastomotic or substitution urethroplasty.

Adolescent↗
PubMed1979

A double blind trial of bromocryptine in the treatment of idiopathic bladder instability.

Fifty-one patients (aged 20 to 68 years) entered a 6-week double-blind trial of Bromocryptine, a dopamine agonist. All patients complained of the complex: frequency, nocturia, urgency and urge incontinence which was due to demonstrable bladder instability. No significant improvement in either symptoms or cystometric findings was seen in the Bromocryptine treated as compared with the control group. A high incidence of nausea was noted in the treated groups. The results of this study suggest that Bromocryptine does not have a therapeutic role in the treatment of idiopathic bladder instability.

Adult↗