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Biomedical subjects

M M Walther

Publications and source records attributed to M M Walther.

At least 109 records · Page 6Linked to original sources
PubMed1993

Iodine-131-metaiodobenzylguanidine scintigraphy in preoperative and postoperative evaluation of paragangliomas: comparison with CT and MRI.

Iodine-131-metaiodobenzylguanidine (MIBG) scintigraphy, transmission computed tomography and magnetic resonance imaging were used to evaluate 36 patients with clinically suspected functioning paragangliomas. The patients were divided into two groups. In Group 1 (n = 21), studied before surgery, patients mainly had benign adrenal disease. In Group 2 (n = 15), studied after surgery, patients frequently had malignant or extra-adrenal tumors. In Group 1, transmission computed tomography and magnetic resonance imaging were more sensitive (100% for both) than MIBG scintigraphy (82%), which, however, was the most specific (100%). In Group 2, MIBG scintigraphy and magnetic resonance imaging were more sensitive (83% for both) than transmission computed tomography (75%), but MIBG was again the most specific (100%). Thus, all three were complementary modalities for localizing paragangliomas both preoperatively and postoperatively. MIBG imaging is indicated for both groups but it is especially recommended for postsurgical patients with recurrence because the disease is often malignant or extra-adrenal.

3-Iodobenzylguanidine↗
PubMed1992

Immunotherapy with interleukin-2 and alpha-interferon in patients with metastatic renal cell cancer with in situ primary cancers: a pilot study.

A total of 12 patients with stage 4 renal cell carcinoma and primary renal tumors in situ was entered into a pilot study using treatment with interleukin-2 and alpha-interferon followed by radical nephrectomy. Of the patients 11 underwent nephrectomy after an initial course of immunotherapy. Ten patients were able to receive a second course of immunotherapy given after nephrectomy. One patient achieved a complete response of lung and mediastinal metastases without any change in the primary renal tumor but after nephrectomy the patient remained in complete remission for greater than 11 months. A total of 3 patients achieved a partial response at some extrarenal sites but they had progression elsewhere. Toxicity was similar to previous experience with this immunotherapy regimen. Therefore, we demonstrated that metastatic tumor regression is possible with primary renal tumors in situ and that aggressive interleukin-2-based immunotherapy can be tolerated in the presence of a large renal tumor.

Adult↗
PubMed1992

The urological manifestations of chronic granulomatous disease.

Chronic granulomatous disease is a rare disorder of phagocytic cell oxidative metabolism. Patients have recurrent infections with catalase positive organisms and granulomatous lesions throughout the body. The genitourinary tract can be an occult site of involvement. We reviewed the prevalence of urological abnormalities in 60 patients with chronic granulomatous disease. Chart review revealed that 23 of the 60 patients (38%) had urological manifestations. Seven patients had 10 ureteral strictures. Treatment of the granulomatous strictures with steroids caused at least a temporary decrease in size or a resolution of the granulomas and strictures with steroids caused at least a temporary decrease in size or a resolution of the granulomas and relief of the obstruction. Three patients had bladder granulomas and 1 had a urethral stricture. A total of 12 patients had urinary tract infections and 7 had altered renal function. Ten patients had other manifestations of genitourinary disease. Abnormalities in the urinary tract are relatively frequent. Risk factors include X-linked disease and low percentile weight. Genitourinary manifestations can cause significant morbidity in chronic granulomatous disease patients. A variety of therapies, including judicious use of steroids and gamma-interferon, are proving to be useful in the treatment of this disorder and in some cases they may offer a nonoperative alternative for relief of chronic granulomatous obstructive disease in these patients.

Female↗
PubMed1992

Suramin: a novel growth factor antagonist with activity in hormone-refractory metastatic prostate cancer.

PURPOSE: Suramin is known to inhibit the growth of malignant prostate carcinoma cells in vitro. This led us to evaluate the effectiveness of suramin in the treatment of 38 patients with prostate carcinoma refractory to hormone therapy. PATIENTS AND METHODS: Suramin was administered by continuous infusion at a rate designed to reach a peak of 300 micrograms/mL at the end of 14 days. Patients were given 8 weeks to recover from any toxicity before beginning the second cycle. Subsequent cycles were administered in the same manner except the starting dose rate was 280 mg/m2. RESULTS: In 17 patients with measurable soft tissue disease, three had complete disappearance of soft tissue disease for 4, 5, and 11 months, whereas three patients had a greater than or equal to 50% decrease in the sum of the products of the diameters of all measurable disease for greater than or equal to 1 month. Of these 17 patients, pretreatment prostate-specific antigen (PSA) decreased by 75% or more in five (29%) and normalized in one (6%). The remaining 21 patients had disease limited to bone, and only one of these experienced resolution of more than 50% of all lesions on bone scan. Of these 21 patients, pretreatment PSA decreased by 75% or more in eight (38%) and normalized in five (25%). Median time to progression for all patients was 26.3 weeks, and median survival was 42.3 weeks. Patients with bone involvement alone exhibited a better survival than patients with soft tissue involvement (P2 = .02). Survival was strongly correlated (P2 = .0001) with a decline in the pretreatment PSA of greater than or equal to 75% by the eighth week on therapy, with nearly an 85% survival at 1 year compared with a 20% survival for those whose pretreatment PSA did not decline by that amount. CONCLUSION: We conclude that suramin is an active agent in hormone-refractory prostate carcinoma.

Aged↗
PubMed1992

Suramin inhibits bone resorption and reduces osteoblast number in a neonatal mouse calvarial bone resorption assay.

The antineoplastic properties of suramin, a polyanionic agent with demonstrated antigrowth factor activity, are under evaluation in vitro, in vivo, and in clinical trials. Suramin has been shown to have antitumor activity in patients with advanced, hormone refractory prostate cancer. During these trials, significant resolution of osseous pain was observed in nearly three quarters of the patients treated with suramin. To evaluate the effect of suramin on bone cells, we studied the effect of suramin on bone resorption in a neonatal mouse calvarial assay. Suramin inhibited bone-resorbing activity in a dose-related fashion and had an additive effect with calcitonin. Calvaria pretreated with suramin had less bone-resorbing activity, fewer attached osteoblasts, and less medium alkaline phosphatase activity than control calvaria. Suramin also inhibited osteoclastic release of tritiated proline from labeled bone in a dose-dependent fashion. The effect of metastatic prostate carcinoma on bone is incompletely understood, but may be moderated by tumor-produced factors and/or cytokines. The effects of several such agents, therefore, were examined in combination with suramin. Bone resorption induced by PTH, epidermal growth factor, tumor necrosis factor, and a tumor-produced factor, PTH related-protein, was blocked by suramin. The ability of suramin to inhibit the bone-resorbing effects of several cytokines suggests that its mechanism may involve direct action on bone metabolism. Autoradiography performed on calvaria treated with labeled suramin demonstrated heavy deposition of suramin on the outer surface of the matrix, adjacent to osteoblasts and osteoclasts lining the outer table, suggesting that bone cells may be subject to high local concentrations of the drug, in keeping with this hypothesis.

Alkaline Phosphatase↗
PubMed1992

The natural history of renal lesions in von Hippel-Lindau disease: a serial CT study in 28 patients.

OBJECTIVE: Von Hippel-Lindau disease is a multisystem disorder predisposing to renal cysts and cancer. The growth and development of these renal lesions have not been documented previously. We reviewed serial CT scans to determine the rates and patterns of growth of renal lesions associated with von Hippel-Lindau disease. SUBJECTS AND METHODS: Twenty-eight patients with von Hippel-Lindau disease and renal involvement, including the spectrum from simple cysts to solid masses, had follow-up examinations for at least 1 year (mean, 2.4 years; range, 1-12 years) with serial contrast-enhanced abdominal CT. Renal lesions were measured and characterized. Surgical correlation was available in 12 patients. RESULTS: Two hundred twenty-eight lesions (eight lesions per patient) were detected. On the basis of their CT appearance, 168 lesions (74%) were classified as cysts, 18 (8%) as cysts with solid components, and 42 (18%) as solid masses. Among 12 patients with pathologic confirmation, the solid components of cystic lesions and solid lesions almost always contained renal carcinoma. The majority of cysts remained the same size (71%) or enlarged (20%); 9% became smaller or entirely involuted during the follow-up period. Although it is generally presumed that renal cysts are precursors to cancers, the transformation of a simple cyst to a solid lesion was observed in only two patients. Among the 42 solid lesions, all but two enlarged with time, with a mean doubling time of 10 months. CONCLUSION: The renal lesions associated with von Hippel-Lindau disease exhibited wide differences in growth. The majority of renal cysts grew slowly but some involuted. Transition to solid renal cancer was rare among cysts. Complex cystic and solid lesions contained neoplastic tissue that uniformly enlarged. These data may be used to help predict the progression of renal lesions in von Hippel-Lindau disease.

Adult↗
PubMed1991

Transvenous occlusion of clinical and subclinical varicoceles.

Forty-four subfertile men with a palpable or clinically suspected varicocele underwent physical examination, nuclear scan, and testicular venography. The ability of these tests to detect a varicocele was compared. The sensitivity of physical examination was 0.94 on the left and 0.35 on the right. Specificity was 0.22 on the left and 0.77 on the right. The sensitivity of nuclear scan was 0.97 on the left and 0.73 on the right. Specificity was 0.56 on the left and 0.50 on the right. Patients with varicoceles demonstrated by venography were treated with testicular vein embolization. There were no complications except two asymptomatic subintimal injections, both of which occurred on the right side. A total of 19 patients had pre- and post-embolization semen analyses performed. The total motile sperm count increased from 27.0 million to 35.5 million. The overall pregnancy rate in the embolization-treated group was 43.7 percent.

Adult↗
PubMed1991

von Hippel-Lindau disease: inadequacy of angiography for identification of renal cancers.

Selective renal angiograms were retrospectively evaluated for the identification of renal cell cancers in patients with von Hippel-Lindau disease (VHL). Seven patients underwent angiography and surgery because of solid or complex renal masses identified at cross-sectional imaging. Nine kidneys underwent detailed examination by the surgeon and by a pathologist. There were 31 renal cancers. Angiography had enabled identification of only five cancers (16%), and six others (19%) had been suspected. Cancers detected angiographically were larger than those not detected (P less than .05). Solid tumors tended to appear less hypervascular than expected and occasionally had the angiographic appearance of atypical cysts. There were no false-positive angiograms. Angiography revealed only one cancer not previously suspected and changed the surgeon's approach for only one kidney (11%). The sensitivity and specificity of angiography were 35% and 100%, respectively. In these patients, selective renal angiography is not helpful for the detection or exclusion of cancer in a kidney. It does not have a limited role for vascular mapping prior to partial nephrectomy or tumor enucleation.

Adult↗
PubMed1991

Use of suramin in treatment of prostatic carcinoma refractory to conventional hormonal manipulation.

Suramin and related compounds, in view of their growth factor and enzyme binding properties, represent in many respects a novel approach to the treatment of cancer. Although in this preliminary analysis of suramin use in the treatment of metastatic prostate cancer, the objective response rate does not appear impressive, much work still needs to be done to optimize suramin's administration to patients and to elucidate its various postulated mechanisms of action. The development of related compounds with more specific enzyme and growth factor antagonist properties is under way.

Adrenal Cortex↗
PubMed1991

Simple renal cysts, atypical renal cysts, and renal cell carcinoma in von Hippel-Lindau disease: a lectin and immunohistochemical study in six patients.

We compare the expression of four markers of renal tubular differentiation in six renal cell carcinomas, five atypical renal cysts, and five simple renal cysts from six patients with von Hippel-Lindau disease. Proximal tubular markers were expressed by five of six renal cell carcinomas, three of five atypical renal cysts, and zero of five simple renal cysts. Distal tubular markers were expressed by one of six renal cell carcinomas, five of five atypical renal cysts, and four of five simple renal cysts. One of the three atypical cysts which expressed distal tubular markers was associated with a renal cell carcinoma which also expressed distal tubular markers. Our findings suggest that simple renal cysts in von Hippel-Lindau disease arise more commonly from distal rather than proximal tubules, while atypical renal cysts show tubular origin similar to renal cell carcinomas.

Biomarkers, Tumor↗
PubMed1990

Surgical management of pheochromocytoma with the use of metyrosine.

Despite recommended preoperative preparation with alpha-adrenergic blockers, severe hemodynamic instability may occur during operations to resect pheochromocytoma. We combined the alpha-blocker phenoxybenzamine with the tyrosine hydroxylase inhibitor metyrosine in an attempt to better manage the hypertension of patients with pheochromocytoma undergoing surgical resection. This report reviews the cases of 25 consecutive patients undergoing surgery for known intra-abdominal pheochromocytoma. Each patient had elevated serum or urine levels of catecholamines or their metabolites. Nineteen patients were prepared before operation with phenoxybenzamine and metyrosine and six patients were given phenoxybenzamine alone. There were no significant differences in maximum, minimum, or mean blood pressure before or after tumor resection between patients who received metyrosine and those who did not. However careful review suggested that those who received metyrosine had more severe disease as judged by biochemical criteria. Study of selected patients matched for age and severity of disease suggested that the intraoperative blood pressure management of patients prepared with phenoxybenzamine and metyrosine was facilitated. In addition metyrosine-prepared patients lost less blood and required less volume replacement during surgery than did non-metyrosine-prepared patients. There were no apparent differences in postoperative fluid requirements. Although the study is not a prospective randomized trial, a retrospective review of patients managed with the combination of phenoxybenzamine and metyrosine suggests that surgery to resect pheochromocytoma can be better performed with both drugs than with phenoxybenzamine alone. The combination regimen appears to result in better blood pressure control, less blood loss, and the need for less intraoperative fluid replacement than does the traditional method of single-agent alpha-adrenergic blockade.

Adrenal Gland Neoplasms↗
PubMed1988

Cytologic features of prostatic adenocarcinoma in urine: a clinicopathologic and immunocytochemical study.

Cells of adenocarcinoma of the prostate (ACP) are infrequently shed in urine. We examined the clinicopathologic features of 22 patients with ACP and tumor cells in urine. Patients typically were clinical stage C or D and had hematuria (13 cases, 59%) and/or obstruction (11 cases, 50%). Prostatic palpation or instrumentation preceded collection of 15 urine specimens. Histologically, tumors were high grade (Gleason score 7-10) and extensive, with involvement of prostatic ducts and acini (10 cases, 45%) and prostatic urethra (5 cases, 23%). Cytologically, the background was clean, and neoplastic cells appeared singly, in loose clusters, as large "casts," or, rarely, in papillary structures. The cells were small, round to oval, with a moderate amount of finely granular or vacuolated cytoplasm; nuclei were generally round with a thin, often irregular membrane, finely granular chromatin, and a single prominent nucleolus. Immunoperoxidase staining for prostatic acid phosphatase and prostate-specific antigen was useful in distinguishing ACP from transitional cell carcinoma.

Adenocarcinoma↗
PubMed1988

Splenic gonadal fusion.

Splenogonadal fusion is a rare anomaly to be included in the differential diagnosis of testicular masses. It is often associated with congenital defects, including peromelia and micrognathia. A case is presented and the literature reviewed.

Gonadal Dysgenesis↗
PubMed1987

Cutaneous horn of penis.

Cutaneous horns of the penis are hyperkeratotic lesions of the skin which arise secondary to chronic irritation. Treatment is local excision with removal of a broad base. Examination of the base is important to rule out carcinoma as the underlying cause of the lesion. A case report is presented and the literature reviewed.

Aged↗
PubMed1987

Periurethral abscess.

From 1963 to 1985, 63 periurethral abscesses were treated in 47 men. The records were reviewed to characterize the natural course of the disease. The most common predisposing factors were a history of gonorrhea, previous periurethral abscess and urethral stricture disease. Treatment consisted of abscess drainage, suprapubic urinary diversion and intravenous antibiotic therapy, consisting of an aminoglycoside and a cephalosporin. Mortality was 1 of 63 patient hospitalizations (1.6 per cent). Improved survival over historical cohorts is attributed to the availability of better antibiotics and medical support.

Abscess↗