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Biomedical subjects

M M Christensen

Publications and source records attributed to M M Christensen.

35 records · Page 2Linked to original sources
PubMed1991

Antimicrobial prophylaxis in transurethral resection of the prostate. With special reference to preoperatively sterile urine.

The literature on antimicrobial prophylaxis in connection with transurethral resection of the prostate (TURP) is reviewed, and it is concluded that there is no proof of clinically significant beneficial effect of prophylaxis when the urine is sterile preoperatively. Prophylaxis is indicated when bacteriuria or an indwelling urethral catheter is present at the time of operation. Other possible risk factors, such as diabetes mellitus, neurogenic bladder dysfunction, immunosuppression, earlier coronary bypass operation and the presence of prosthetic devices, need further investigation.

Anti-Bacterial Agents↗
PubMed1990

Critical evaluation of transurethral resection and incision of the prostate.

Next to cataract extraction, surgical treatment of benign prostatic hyperplasia is the second most prevalent surgical procedure in the United States, with an estimated 400,000 transurethral resection procedures performed annually. A critical evaluation and brief history of transurethral resection and incision of the prostate for benign prostatic hyperplasia follows.

Aged↗
PubMed1990

A guinea pig model for study of bladder mast cell function: histamine release and smooth muscle contraction.

To study the function of mast cells in bladder tissue, guinea pigs were sensitized with ovalbumin by intraperitoneal injections, bladder tissue strips were superfused, and tissue contractile force and histamine release were studied. Upon challenge with ovalbumin, bladder tissue contracted 64 +/- 4% (mean +/- S.E.M.) of the maximum carbachol contraction and released 14.1 +/- 1.6% of the total tissue histamine content. Incubation of sensitized bladder tissue with indomethacin led to an increased force and duration of the contraction while incubation with nordihydroguaiaretic acid combined with pyrilamine reduced histamine release and abolished the contraction. Tissue histamine content was significantly higher in the bladder neck than in the dome, and significantly elevated following sensitization. Histochemical studies of bladder tissue demonstrated mast cell degranulation in antigen challenge experiments. In addition, a group of guinea pigs were sensitized to ovalbumin through bladder instillations. With this model, study of the functional characteristics of bladder mast cells and the acute actions of mast cell products on the bladder microenvironment, should now be feasible.

Animals↗
PubMed1990

Clinical manifestations of benign prostatic hyperplasia and indications for therapeutic intervention.

The symptomatology of benign prostatic hyperplasia is a complex issue, and the clear-cut indications for therapeutic intervention are few. Overflow incontinence is a clear indication for treatment, and it seems prudent to recommend surgical intervention for patients with large postvoiding residual volumes. Acute urinary retention, recurrent infection, azotemia, and severe hematuria are other strong indications. When the indications are less clear, the patient's perspective on the impact of prostate disease on his life is important.

Humans↗
PubMed1990

Transurethral resection versus transurethral incision of the prostate. A prospective randomized study.

In this ongoing study, patients with an estimated prostate size of no more than 20 gm are randomized to undergo either transurethral resection of the prostate (TURP) or transurethral incision (TUIP) at the 6 o'clock position. To date, 93 patients have been included, and 3 months postoperatively, 80 to 90 per cent of the patients in each group reported improvement. There was also a significant decrease in symptom scores and a significant increase in maximum urinary flow rate, with great variation within each group but without difference between the groups. In both groups, there appears to be some deterioration over time. Operating time, estimated blood loss, time to catheter removal postoperatively, and duration of postoperative hospital stay were all significantly in favor of TUIP. Loss of ejaculation was reported by 37 per cent of patients after TURP and by 13 per cent after TUIP (not statistically significant). There was no difference between the groups in the need for further surgery. Therefore, TUIP is recommended as an alternative to TURP in patients with small prostates.

Adult↗
PubMed1990

Reasons for delay of endocrine treatment in cancer of the prostate (until symptomatic metastases occur).

The VACURG studies showed that 1) In early (stage I and II) cancer of the prostate, radical prostatectomy dose not increase survival compared with initial placebo treatment, it is therefore a definite option (and possibly advisable) to initially just observe the patients with early cancer of the prostate (the "watch and see" or "watchful waiting" policy), 2) 1.0 mg as well as 5.0 mg DES daily retards progression from stage III to stage IV but does not improve survival in stage III, 3) 5.0 mg DES daily is associated with increased risk of cardiovascular death, and 4) in stage IV patients, early endocrine treatment (e.g. 1 mg DES) is advisable, especially in younger patients with high-grade tumors.

Combined Modality Therapy↗
PubMed1989

Symptom analysis and uroflowmetry 7 years after transurethral resection of the prostate.

The long-term result after transurethral resection of the prostate is not well documented. From 1981 to 1983, 84 consecutive consenting patients completed detailed symptom analysis and urodynamic examination before transurethral resection of the prostate. These studies were repeated 3 and 12 months postoperatively. Of the 84 patients 44 were interviewed at 86 months: 75% reported improvement compared to preoperative symptoms. In addition, 23 patients underwent uroflowmetry at 7 years. For this group the maximum urine flow rate remained virtually unchanged from 1 to 7 years postoperatively). When uroflowmetry results from all patients undergoing testing at the various followup intervals are considered, the maximum urine flow rate was 9.5 ml. per second preoperatively, 17.0 ml. per second at 3 months and 19.6 ml. per second at 1 year. Of the 44 patients 7 (16%) underwent repeat transurethral resection of the prostate.

Aged↗
PubMed1989

Urethral strictures after transurethral bladder tumor resection.

The charts on 241 patients, consecutively undergoing a total of 2043 transurethral resections of bladder tumors and subsequent controls, were reviewed to find the incidence and possible causes of postoperative urethral stricture. The incidence of urethral stricture was 15% in males and 4% in females, but less than one-third were symptomatic. The strictures were found distally in the urethra in 83% of the patients and were treated with optical urethrotomy. Cumulated duration of postoperative catheterization was significantly longer and size of resectoscope used larger in patients with stricture. Repeated transurethral instrumentations may increase the risk of stricture development.

Female↗
PubMedDate not supplied

Histochemical tracing of bismuth in testis from rats exposed intraperitoneally to bismuth subnitrate.

The histochemical silver amplification technique autometallography (AMG), was used to trace bismuth in the testis of Wistar rats injected intraperitoneally with bismuth subnitrate. In the seminiferous tubules, bismuth was located in lysosomes of Sertoli cells closely associated with heads of spermatids in the late stages of the spermatogenesis, i.e. shortly before the release of Step 19 spermatids in Stage XIII. No bismuth-specific AMG silver grains were detected in the spermatogenic cell line. However, tails of free sperm cells located in the tubular lumen showed autometallographic grains in close contact to the nine outer microtubule doublets in the axonema. Leydig cells concentrated huge amounts of AMG-bismuth in their lysosomes. Furthermore, parallel exposure to selenium significantly increased the amount of histochemically traceable bismuth in the rat testis.

Animals↗