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Biomedical subjects

M Dunn

Publications and source records attributed to M Dunn.

At least 145 records · Page 8Linked to original sources
PubMed1981

Surgical management of urethral stricture in the male.

Urethral dilatation has long been the standard treatment for patients with urethral stricture. However, in many patients such dilatations may be difficult, painful, or have to be done at frequent intervals. The alternative techniques of direct vision urethrotomy or urethroplasty have been considered in 101 patients over a twelve-year period. Skin inlay urethroplasty in this series showed a significant level of complications and an absolute failure rate of 15 per cent. A prospective study of 39 patients undergoing urethrotomy using the Sachse optical urethrotome has shown that 82 per cent of patients are symptom-free and 13 per cent symptomatically improved at a follow-up ranging from sixteen months to three and one-half years (mean twenty-five months). We believe that urethrotomy using the Sachse optical urethrotome should now be the initial treatment of choice in the management of urethral stricture. Urethral dilatations or urethroplasty should be reserved for those patients who have persisting stricture despite such urethrotomy.

Adolescent↗
PubMed1980

A cell cycle study of the effects of Con A on synchronized mouse embryo fibroblasts: arrest at two specific stages of the cycle and dissociation between uptake of thymidine and DNA synthesis.

We have examined the effects of 50 microgram ml-1 of Con A added to synchronized mouse embryo fibroblasts at different times during the cell cycle. We found that Con A caused arrest of growth not solely by preventing G1-G0 cells from entering the S-phase but also by exerting a G2 block. We also found that Con A, which prevented commencement of S-phase, did not arrest cells already in S from reaching the G2 stage but inhibited the S-phase associated process of thymidine uptake. The inhibition was greater when the Con A receptors were extensively clustered.

Animals↗
PubMed1980

Echocardiographic evaluation of mitral stenosis in predicting mitral valve replacement vs commissurotomy. Relation to hemodynamic measurements.

Fifty-one patients with mitral stenosis were studied by M-mode echocardiograms to verify the possibility of predicting if they will require mitral valve replacement or commissurotomy. Fifteen of 18 patients with heavy calcification and restricted or poor valvular mobility underwent mitral valve replacement. Twelve of 14 patients with normal valve amplitude underwent mitral commissurotomy regardless of the presence of valvular calcification. A newly derived measurement, the MT/ST, which is the ratio between the maximal thickness of the widest echo from the mitral valve and the maximal thickness of the left ventricular margin of the interventricular septum, was used to assess valvular calcification. Values above 1.7 were present only in valves with restricted or poor mobility and indicated mitral valve replacement in 14 of 15 cases. All of the patients undergoing mitral valve replacement who had MT/ST ratios between 1.5 and 1.7 had restricted or poor valvular mobility. Of the patients with MT/ST ratios less than 1.5, ten of 12 with normal valvular amplitude underwent mitral commissurotomy, and four of five with restricted valvular mobility underwent mitral valve replacement. We conclude that echocardiographic assessment of mitral valvular calcification and amplitude is useful in predicting patients who will require mitral valve replacement vs mitral commissurotomy.

Adolescent↗
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↗