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Biomedical subjects

R D Williams

Publications and source records attributed to R D Williams.

At least 109 records · Page 6Linked to original sources
PubMed1990

Current options in the management of clinical stage C prostatic carcinoma.

The evaluation of clinical stage C prostatic cancer has been enhanced by advances in staging modalities over the past 15 years. Better staging of the local lesion is possible with transrectal ultrasound-guided multiple biopsies of the prostate and its vicinity. Biopsies of suspect pelvic lymph nodes guided by CT (or lymphangiography) may obviate pelvic lymphadenectomy, particularly in patients with high-grade stage C lesions. Advances in the understanding of serum markers have supplemented other staging information. No single therapeutic modality is appropriate for all cases of clinical stage C cancer. In C1 lesions, radical prostatectomy with adjunctive radiation or hormonal therapy seems to produce the best 5- and 10-year survival rates. External-beam radiation alone, or in combination with interstitial radiation, may have equivalent success. In clinical stage C2 disease, external-beam radiotherapy seems at present to be the best therapeutic modality. Interstitial radiation as a sole method of management in stage C disease carries a high local recurrence rate and a significant risk of metastatic progression. Transurethral prostatectomy and hormonal treatment continue to have a place in the management of selected poor-risk patients. The current results with surgery or radiation therapy alone are less than ideal. It is recommended that aggressive combination treatment be compared with monotherapy in randomized clinical trials monitored jointly by radiation and urologic oncologists.

Combined Modality Therapy↗
PubMed1989

Pathophysiology of transitional tumor cell adherence to sites of urothelial injury in rats: mechanisms mediating intravesical recurrence due to implantation.

The mechanism by which transitional tumor cells adhere to areas of urothelial injury and the means by which heparin prevents this phenomenon were studied. Scanning electron microscopy and a radiolabeled tumor cell adherence assay were used to assess the activity of heparin and a "nonglycosaminoglycan" thrombolytic agent, recombinant tissue plasminogen activator, in preventing tumor cell adherence to areas of urothelial injury. Systemically administered heparin and intravesical therapy with recombinant tissue plasminogen activator duplicated the activity of intravesical heparin. Scanning electron microscopy showed tumor cells entrapped at the injury surface in a RBC/fibrin clot, which was prevented by intravesical heparin. These data suggest that clotting cascade activation by urothelial injury is the mechanism by which particulate adherence to the urothelium occurs. Interruption of this process by local or systemic anticoagulation with heparin or shifting of the equilibrium of clot formation/lysis toward thrombolysis with recombinant tissue plasminogen activator prevents tumor cell adherence. Intravesical thrombolytic therapy may represent a new approach to recurrence prophylaxis for superficial bladder carcinoma.

Animals↗
PubMed1989

Construction of the intestinal stoma with an intraluminal stapling device.

We have used the intraluminal circular stapler to facilitate construction of the intestinal conduit stoma. We have encountered no complications related to the stapled stoma construction technique in 8 patients. The stoma is circular, uniform in size and is fitted easily with an appliance. The circular staple line provides a watertight seal that prevents contamination of the subcutaneous tissues. The technique is rapid, reliable and reproducible.

Colostomy↗
PubMed1989

Magnetic resonance imaging in the diagnosis and followup of idiopathic retroperitoneal fibrosis.

Four cases of idiopathic retroperitoneal fibrosis are reported. Magnetic resonance and computerized tomographic images were obtained for diagnosis in each case, and followup scans were obtained at various intervals after therapy. In all 4 cases magnetic resonance imaging was equal or superior to computerized tomography in the diagnosis of retroperitoneal fibrosis, outlining the extent of involvement, preoperative planning and assessing response to medical or surgical therapy.

Aged↗
PubMed1989

Studies on the stability and detection of cocaine, benzoylecgonine, and 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid in whole blood using Abuscreen radioimmunoassay.

A study was undertaken to assess the stability and the radioimmunoassay (RIA) detection of cocaine, benzoylecgonine (BZE), and 11-nor-delta-9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH) in whole blood while stored in 4 different kinds of blood collection tubes for up to 30 days at refrigeration and room temperatures. At various intervals, the tubes were sampled and analyzed using Abuscreen RIA. Also, semi-quantitative data derived from RIA analysis of forensic blood specimens were compared with quantitative data acquired using gas chromatography (GC) or GC/mass spectrometry (GC/MS) on the same specimens. RIA and chromatographic studies revealed that BZE and THC-COOH were stable in blood under all conditions studied. Cocaine, however, was found not to be stable in blood, especially when stored at room temperatures. Despite cocaine's instability in blood, RIA was able to detect the presence of cocaine and its breakdown products in blood under all conditions studied.

Blood Preservation↗
PubMed1988

Renal sinus malignant lymphoma: a case report.

We report a case of renal sinus non-Hodgkin's lymphoma without contiguous adenopathy. Magnetic resonance and computed tomography images of this rare tumor were correlated with a pathologic specimen. On computed tomography the renal sinus lymphoma was evaluated as a well circumscribed, low-density mass owing to the mixture of the lymphomatous cells and fat tissues. Magnetic resonance showed the replacement of the renal sinus fat tissues with a spoke-like solid mass. The renal artery and vein were also evaluated thoroughly and were without tumor thrombosis.

Female↗
PubMed1988

Alpha-interferon in superficial bladder cancer: a Northern California Oncology Group Study.

Thirty-five patients with superficial transitional carcinoma of the bladder were treated intravesically with escalating doses of recombinant alpha-2-interferon administered weekly for 8 weeks. Of the 19 patients with high-grade intraepithelial neoplasia (17 carcinoma in situ [CIS], two severe dysplasia, all cytology positive), six (32%) had complete resolution of all histologic and cytologic evidence of disease (complete response). An additional three patients (16%) had complete resolution of CIS, but the interval appearance of a low-grade transitional cell neoplasm. Five (26%) had a partial response (complete resolution of all evidence of CIS on multiple bladder biopsies but persistently positive cytologic preparations). Sixteen patients with recurrent papillary tumors and extensive prior therapy were also treated. Four (25%) had a complete response. Twenty-three of the 35 patients had prior intravesical therapy. Seven of the 23 (30%) patients with prior intravesical chemotherapy or immunotherapy had a complete or partial response to interferon, while eight of the 12 patients (67%) without prior intravesical treatment responded. These responses were achieved with minimal local and systemic toxicity. Of the ten complete responders, five remain in continuous unmaintained remission for 18+ to 37+ months. Intracavitary alpha-2-interferon is an effective new treatment for some patients with bladder cancer.

Adult↗
PubMed1988

Surgical removal of an "inoperable" neurofibroma.

An 8-month-old girl had ipsilateral ptosis, proptosis, and glaucoma caused by a massive left-sided plexiform neurofibroma. The tumor extended from the cavernous sinus into the orbit, involving the optic nerve, extraocular muscles, and eyelid. Although the prognosis in such cases is considered very poor, most of the mass was excised by a radical neurosurgical and ophthalmologic procedure. Today, the patient remains asymptomatic with no further neurologic defects. This case is unusual in that the glaucoma developed prior to clinically evident eyelid involvement.

Blepharoptosis↗
PubMed1987

Testicular failure in patients with extragonadal germ cell tumors.

Eight patients with mediastinal or retroperitoneal germ cell tumors who had undergone testicular biopsy or orchiectomy were retrospectively analyzed for primary testicular abnormalities, subfertility, and abnormal sex hormone levels. Testicular tissue was abnormal in all patients, revealing peritubular fibrosis (six), decreased spermatogenesis (eight), interstitial edema (five), Sertoli cells only (one), and Leydig cell hyperplasia (two). Detailed hormone analysis in five patients revealed elevations of luteinizing hormone in four, decreased serum testosterone in two, elevations of estradiol in two, and elevation of human chorionic gonadotropin in one patient. A history of infertility was documented 2 months to 13 years before presentation in four patients and suspected in another. Extragonadal germ cell tumors, like their testicular counterparts are associated with primary germ cell defects, some of which seem to be independent of gonadotropin production by the tumor. In addition, the rather high incidence of antecedent infertility suggests that either a congenital or acquired primary germ cell defect contributes to defective spermatogenesis and the development of cancer in incompletely migrated germ cells.

Adolescent↗
PubMed1987

Synthesis of messenger RNAs for transforming growth factors alpha and beta and the epidermal growth factor receptor by human tumors.

Human tumors and tumor cell lines were analyzed for the presence of mRNA coding for transforming growth factors alpha and beta (TGF-alpha and -beta) and the epidermal growth factor receptor. TGF-alpha mRNA was not detectable in hematopoietic tumor cell lines but was found in a variety of solid tumor cells, particularly carcinomas. Many of the tumors that contained TGF-alpha mRNA also expressed high levels of epidermal growth factor receptor mRNA. The concentration of TGF-alpha in the media of several tumor cell lines did not necessarily correlate with TGF-alpha mRNA levels, as a substantial fraction of TGF-alpha can remain cell associated. The levels of TGF-beta mRNA in tumor cell lines and tumor specimens were variable, but higher in tumors than in the adjacent normal tissues.

Cell Line↗
PubMed1987

Magnetic resonance imaging evaluation of radiation-induced changes in experimentally implanted renal cell carcinoma.

The effect of radiation on the magnetic resonance imaging appearance and relaxation parameters of human renal cell tumors implanted in male white-Swiss athymic nude mice was evaluated. Twenty-three mice were treated with external beam radiation, receiving a total dose of 2,500 rads administered in a single treatment limited to subcutaneous tumor. Twenty-two tumor-bearing mice served as control animals. Experimental and control mice were studied with MRI at four (n = 9), seven (n = 20), 14 (n = 8), and 28 (n = 8) days following experimental radiotherapy. A 0.35 tesla superconductive MRI system was employed. Images were generated using spin-echo technique with repetition times (TR) of 500 and 2,000 ms and echo-delay times (TE) of 28 to 30 and 56 to 60. Relaxation time calculations were made on the basis of tumor signal-intensity measurements in assigned regions of interest. The MRI appearances and relaxation times of irradiated tumors that decreased in size following treatment, irradiated tumors that grew, and control tumors were similar, as were their histologic features. No statistically significant differences could be detected in relaxation times of the four experimental and four control groups. Statistical evaluation was performed using analysis of variance. Further investigation of MRIs potential in tissue characterization following radiotherapy is warranted, but evaluation of change in tumor dimensions remains the most reliable indicator of therapeutic response.

Animals↗