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Biomedical subjects

W W Koontz

Publications and source records attributed to W W Koontz.

At least 19 recordsLinked to original sources
PubMed1992

The effect of polyethylene glycol-superoxide dismutase administration on histological damage following spermatic cord torsion.

Oxygen free radicals generated during the ischemic/reperfusion period have been suggested as a possible cause for tissue damage in different organs. In this study we address the question of whether administration of polyethylene glycol-superoxide dismutase, an oxygen free radical scavenger, can alleviate histological damage associated with testicular torsion. The study included 67 Sprague-Dawley rats. In 60 rats the left testicle was rotated 720 degrees clockwise through a scrotal incision. Torsion duration was 3 hours. Five minutes before and 5 minutes after detorsion the testicle color was evaluated and scored. The remaining 7 rats underwent a sham operation. After randomization 8,000 units per kg. polyethylene glycol-superoxide dismutase were injected intraperitoneally in the treated group 1 hour before detorsion. After 14 days histological evaluation was performed on both testicles of 58 rats (2 rats died before the evaluation). No statistically significant difference was demonstrated between the treatment (28 rats) and the control groups (30 rats). Testicular color after detorsion correlated with the histological damage.

Animals↗
PubMed1992

Effects of lithotripter-generated high energy shock waves of mammalian cells in vitro.

The effects of high energy shock waves on an established human prostatic carcinoma cell line (PC-3) were investigated. HESW were administered to PC-3 cell suspensions using an electrohydraulic lithotripter (Dornier HM3). Experimental variables included the number of shocks to which the cells were exposed, spark generator potential, and the position of the cell sample in the acoustic field. Two types of cellular damage were observed: immediate cell destruction (lysis) as measured by electronic particle counting and the loss of reproductive capacity (viability) among the remaining cells as determined by colony formation assay. Over the range of the experimental variables studied, cell lysis was dependent to a greater extent on the number of shocks administered than the generator potential. Viability was affected less but was also dependent on both the generator potential and shock number. Cell lysis was strongly dependent on the position of the sample in the acoustic field with the extent of damage increasing as the sample was moved along the central axis of the shock wave from the f2 focus towards the electrodes. Possible mechanisms of damage and the relationship of the in vitro effects to the damage observed in normal tissues of patients undergoing extracorporeal lithotripsy for kidney stone disease are discussed.

Cell Division↗
PubMed1991

Immunohistochemical detection of c-erbB-2 protein in human benign and neoplastic prostate.

Both the polyclonal anti-c-erbB-2 peptide antiserum pAB 60 and the monoclonal anti-c-erbB-2 protein antibody mAB-1 detect the c-erbB-2 protein in human breast adenocarcinomas. We investigated c-erbB-2 expression in adult human benign hyperplastic and neoplastic prostates, using the avidin-biotin complex immunoperoxidase method. Formalin-fixed, paraffin-embedded specimens of benign hyperplastic prostate (13), prostatic adenocarcinoma (22), and prostatic adenocarcinoma lymph node metastases (two) were tested with pAB 60. Ten formalin-fixed, paraffin-embedded specimens of prostate adenocarcinoma, 11 frozen sections of benign hyperplastic specimens, and eight frozen sections of prostate adenocarcinoma were tested with mAB-1. Our results demonstrated consistent detection of c-erbB-2 immunohistochemically in frozen sections of both benign and malignant prostate. Preincubation of pAB 60 with the immunizing peptide blocked subsequent reactivity with prostatic tumor tissue, indicating specificity. However, fixation and processing protocols significantly affected the reactivity of the antigenic determinants detected by these antibodies, as mAB-1 was nonreactive with formalin-fixed, paraffin-embedded prostatic tissues. Differential reactivity of pAB 60 with malignant rather than benign glands was maximized by exposure of the specimen to the antibody at 4 degrees C rather than 22 degrees C. The most frequently observed staining pattern with both antibodies was cytoplasmic. However, mAB-1 produced distinctly membranous staining in two frozen specimens of benign hyperplasia and one specimen of prostate cancer.

Adenocarcinoma↗
PubMed1991

Effect of radiation combined with hyperthermia on human prostatic carcinoma cell lines in culture.

The effect of radiation combined with heat on three human prostatic carcinoma cell lines growing in vitro was investigated. Cells were exposed to different radiation doses followed by heat treatment at 43 degrees C for one hour. Heat treatment, given ten minutes after radiation, significantly enhanced the radiation response of all the cell lines studied. The combined effect of radiation and heat produced greater cytotoxicity than predicted from the additive effects of the two individual treatment modalities alone. These results indicate that a combined treatment regimen of radiation plus hyperthermia (43 degrees, 1 hr) might be an important tool in maintaining a better local control of prostatic cancer.

Cell Survival↗
PubMed1991

The effect of radiation therapy and hyperthermia on a human prostatic carcinoma cell line grown in athymic nude mice.

The effect of radiation and/or hyperthermia on a human prostatic carcinoma xenograft in athymic nude mice was investigated. A human prostate carcinoma subline (1-LN-PC-3-1A) was inoculated subcutaneously in the thigh of male athymic nude mice. When tumors reached a size of approximately 200 mm.3, they were treated with either radiation (X) or hyperthermia (H) alone, or in combination (X + H). In the combined treatment, hyperthermia was delivered immediately after radiation exposure. Comparison of the time required to reach twice the tumor volume observed at the time of treatment was used to define therapeutic impact on tumor growth. The combined treatment resulted in median tumor volume doubling time of 35.5 days, compared to 18 days and 25.5 days, respectively, for hyperthermia or radiation alone. Analysis of tumor doubling time using a proportional hazards regression indicates that under the conditions of this experiment, the effect of radiation and hyperthermia for 1-LN-PC-3-1A tumors is additive. The impact of this treatment regimen in the management of prostatic cancer requires further investigation.

Animals↗
PubMed1989

The effect of hyperthermia on human prostatic carcinoma cell lines: evaluation in vitro.

The effect of hyperthermia on established human prostate carcinoma cell lines (PC-3, DU-145) and related sublines (1-LN, 125-1L) was investigated in vitro. Cells were exposed to heat treatment at 43C or 37C for varying time intervals, (one hr or two hrs) and cell survival was evaluated by the colony formation assay and by measurement of cellular growth rate. While one hr exposure at 43C did show a mean inhibition of colony formation, ranging from 29 to 41%, a statistically significant increase in inhibition rate (p less than 0.001) was observed at two hr exposure, ranging from 57 to 92%. This study is a report of the cytotoxic effect of hyperthermia on established human prostatic tumor cell lines. These in vitro results indicate that hyperthermia may become a potentially useful form of adjunctive therapy for local control of prostatic cancer. However, the temperature and exposure time may have an important impact on cell kill when this new modality for cancer treatment is proposed for a clinical trial.

Cell Line↗
PubMed1989

Segmental medullary sponge kidney mimicking a renal mass.

We report an unusual case of a medullary sponge kidney that presented clinically and radiologically as a renal mass. Histopathological study after nephrectomy proved the mass to be consistent with segmental medullary sponge kidney.

Diagnosis, Differential↗
PubMed1989

Twenty-five years of renal trauma at a teaching hospital.

In a study of 535 patients with renal trauma admitted to the Medical College of Virginia Hospitals from 1962 to 1988, the authors found indications of a decrease in the rate of total nephrectomy in patients with blunt trauma, due in part to advances in diagnostic technology. In the cases of gunshot wounds, however, a persistently high rate of nephrectomy prevailed, reflecting, the authors believe, the proliferation of increasingly lethal weaponry.

Humans↗
PubMed1988

Intravesical thiotepa versus mitomycin C in patients with Ta, T1 and TIS transitional cell carcinoma of the bladder: a phase III prospective randomized study.

A prospective randomized clinical trial was conducted by the National Bladder Cancer Group to compare thiotepa and mitomycin C in ablating residual Ta, T1 and TIS transitional cell carcinoma of the bladder. Eight weekly instillations were given followed by cystoscopy 4 weeks after the treatment was stopped. The over-all complete response rate based on cystoscopy and either biopsy or cytology was 26 per cent for thiotepa versus 39 per cent for mitomycin C (p equals 0.08). The greatest efficacy was seen in the Ta group with mitomycin C demonstrating superiority over thiotepa. Patients with negative cystoscopy and biopsy but who had positive cytology were considered to be partial responders. When partial and complete responders were combined the over-all response rate was 53 per cent for thiotepa and 63 per cent for mitomycin C (p equals 0.23). Patients with TIS appeared to respond equally to thiotepa and mitomycin C. Toxicity included urinary frequency in 22 of the 73 patients in the thiotepa arm and 31 of the 76 patients receiving mitomycin C. A rash was observed in 2 of the thiotepa group versus 14 of the mitomycin C group. Bone marrow depression occurred in 15 patients receiving thiotepa and in 12 receiving mitomycin C.

Administration, Intravesical↗
PubMed1985

Mitomycin for patients who have failed on thiotepa. The National Bladder Cancer Group.

The National Bladder Cancer Group undertook a study to determine the effectiveness and toxicity of mitomycin in patients who failed on thiotepa. A total of 117 patients with residual superficial transitional cell bladder cancer (Ta, T1, Tis) who had previously failed on intravesical thiotepa were treated with 40 mg of mitomycin instilled intravesically weekly for eight weeks. Four to six weeks after the last treatment, tumor response was evaluated by cystoscopy, biopsy of the site of the index lesion, and cytology. In 57 patients (48.7%), visible tumor had been ablated. Results of cystoscopy, biopsy, and cytology were negative in 32 (27.4%) patients. Eleven patients (9.4%) had no visible tumor and negative cytology unconfirmed by biopsy. In 14 patients (12%) who had complete destruction of the tumor at cystoscopy, and biopsy specimen was negative for tumor, cytology was positive, indicating a partial response. Six patients (5.1%) withdrew from the study before the first evaluation because of local toxicity (cystitis).

Administration, Topical↗