Growth characteristics and immunogenicity of the R-3327 rat prostate carcinoma

The transplantable R-3327 prostate adenocarcinoma (Dunning tumor) has been studied in the Copenhagen rat. We present information about androgen-dependent and hormone-independent tumors in regard to metastasis, growth rate, extrapolated cell kinetics, and response to treatment.

Prostatic maldevelopment in the prune belly syndrome: a defect in prostatic stromal-epithelial interaction

The prune belly syndrome consists of a triad of abdominal wall musculature deficiency, cryptorchidism and urinary tract anomalies. A rarely described but fairly constant component of the syndrome is the lack of development of the epithelial elements of the prostate. We wish to suggest that this is a further expression of a postulated arrest in mesenchymal development responsible for other features of the syndrome.

Abnormalities in the sequence of filling and emptying of mesenteric arteries and veins: a guide to ischemic disease of the bowel

Functional abnormalities in the sequence of filling and emptying of mesenteric arteries and veins may indicate significant disease of the bowel which is not associated with identifiable structural alterations in the blood vessels. In three patients, focal ischemic damage to the bowel was associated with significantly delayed arterial emptying, delayed or absent filling and emptying of mesenteric veins or a combination of both. Evaluation for sequential filling and emptying of vessels proved most helpful since an abnormal pattern may represent the only angiographic abnormality indicative of intestinal infarction.

Clinical significance of serum alkaline phosphatase isoenzyme levels in advanced prostatic carcinoma

The alkaline phosphatase isoenzymes in 105 patients with stage D carcinoma of the prostate who entered the National Prostatic Cancer Study were analyzed and these values were correlated to clinical response. Only patients with at least 3 measurements of alkaline phosphatase were evaluated. In 91% of patients with metastatic bone disease, bone alkaline phosphatase was elevated. Those patients with higher pre-treatment levels of alkaline phosphatase generally showed a poorer response to therapy. The results of alkaline phosphatase isoenzyme estimation indicate that these biological markers may be used in the evaluation of patients with metastatic prostatic cancer to predict and monitor their response to chemotherapy. The evaluation of bone and liver alkaline phosphatase isoenzymes in earlier stages also may be valuable.

Immunochemical detection of serum prostatic acid phosphatase. Methodology and clinical evaluation

An immunochemical method for detection of prostatic acid prosphatase is described. Purified acid phosphatase was isolated from cancerous human prostate. A specific antiserum to the purified enzyme was produced in rabbits. The antiserum to postatic acid phosphatase did not react with acid phosphatase originating from other tissues. A counter immunolectrophoresis, utilizing the specific antibodies and a chemical staining technique, has been developed and clinically evaluated. Sera from patients with prostatic carcinoma (6/20 of stage B, 27/49 of stage C, and 98/125 of stage D) gave positive results. Sera from 19 patients with benign prostatic hypertrophy, from 89 patients with other tumors, from 12 patients with Gaucher's disease, from 107 healthy volunteers, and from 50 normal age-matched men all gave negative results. The sensitivity of this method was 0.4 IU of enzyme activity or 20 ng per ml of prostatic acid phosphatase protein. Further clinical evaluation of patients in the early stage of prostatic cancer and of patients undergoing chemotherapy is in progress.

Beneficial effect of propranolol in a histologically appropriate model of postischemic acute renal failure

Acute renal failure caused in the rabbit by clamping one renal pedicle for 1 hour and removing the opposite kidney produced a histologic picture very similar to that observed in "hypotensive" acute renal failure in man. Intravenous infusion of propranolol, a drug which prevents renin release, at 1 mg/kg for 70 minutes beginning at time of pedicle clamping resulted in significantly lower serum creatinine in this model (2.8 +/- 0.2 mg% at 48 hours with propranolol versus 5.2 +/- 0.8 mg% without). Renin stimulation by dehydration or feeding a low-salt diet enhanced the difference between treated and untreated groups (2.6 +/- 0.4 mg% with propranolol versus 6.2 +/- 1.8 mg% without, after dehydration; 3.5 +/- 1.0 mg% with propranolol versus 7.6 +/- 1.4 mg% without, after low-salt diet).Suppression of renin production by saline feeding eliminated propranolol's beneficial effect (5.6 +/- 0.9 mg% with propranolol versus 4.0 +/- 0.6 mg% without). In rabbits with a normal food and water intake, renal denervation using phenol also eliminated propranolol's effect (creatinine 8.6 +/- 1.4 mg% with propranolol versus 8.6 +/- 1.8 mg% without). In rabbits with intact kidneys, flow probe recording of renal blood flow showed a significantly higher blood flow immediately after unclamping in the propranolol-treated animals, and renal angiograms showed less vasoconstriction in this group after unclamping. In this model of acute renal failure, renal vasoconstriction plays an important role following the initial ischemic insult. Propranolol lessens the severity of this vasoconstriction and the resulting acute renal failure. Its probable action is interference with neurogenically stimulated renin release.

Experimental models for the study of prostatic adenocarcinoma

The Dunning R3327H transplantable rat tumor is a well differentiated prostatic adenocarcinoma. The biological properties of this tumor have been characterized, and it appears that this animal model is well suited for studying the nature of prostatic cancer. The established tumor responds to castration therapy and this is subsequently followed by relapse to a predominant state of hormone insensitivity. Cell kinetic studies indicate that 70 to 90 per cent of the total tumor cells are hormonally sensitive, and a subpopulation of 8 to 30 per cent are hormone insensitive. The therapeutic relapse to androgen deprivation represents the continued growth of the clone of cells, which were hormone insensitive. It appears that this animal mimics the relapse of phenomenon observed in the hormone control of human prostatic cancer.

Functional abnormalities, of mesenteric blood flow. A guide to organic disease of the bowel

Analysis of functional as well as anatomic aspects of blood flow greatly increases the diagnostic accuracy of superior mesenteric artery angiography. In almost all normal individuals the major branches of the superior mesenteric artery empty within a spain of two seconds. The corresponding draining veins all first appear within a two second span. Deviations from the pattern must be explained, as they usually signal abnormality. Five pertinent cases illustrate functional abnormalities leading to the detection of tumors where definite tumor vascularity was not demonstrated, the localization of a bleeding site where extravasation was not detected, and the recognition of obstructing adhesive bands.

B-scan ultrasound in the diagnosis of popliteal aneurysms

Sonography gives a characteristic picture of popliteal aneurysms, with an easily demonstrable connection of the sonolucent aneurysmal sac with the popliteal artery. It is a good screening procedure for suspected aneurysms and for patients with popliteal pain, mass, or sudden distal ischemia. Three case reports of five popliteal aneurysms diagnosed by ultrasound are presented. A case of neurofibrosarcoma occurring in the popliteal fossa is shown for comparison.

Characterization of the Dunning R3327H prostatic adenocarcinoma: an appropriate animal model for prostatic cancer

The Dunning R3327H rat prostatic adenocarcinoma appears to be an appropriate animal model for studying prostatic cancer. This report contains a detailed characterization of this tumor at the morphologic, biochemical, and therapeutic levels. Electron micrographic, histologic, and histochemical studies clearly establish the adenocarcinoma nature of this tumor. The histology of the R3327H tumor is similar to well-differentiated human prostatic cancer. The biochemical and enzymatic profile of the tumor indicates its origin from the rat dorsolateral prostate. The cell kinetics and growth rates of this tumor following a variety of hormonal manipulations (castration, estrogens, androgens, and antiandrogens) have established that 70%-90% of the cells in this tumor require androgens for their growth. However, 10%-30% of the cells are capable of growth in the absence of androgens. Both cell types are present in the initial tumor inoculum and these different cell types possess similar growth rates. The predominance of the androgen-sensitive cells accounts for the relatively greater size of the tumor achieved in the intact male animal at a given growth time. After the tumor is well established in an intact animal, subsequent estrogen therapy or castration resulted in a marked diminution in tumro volume. This was followed by a subsequent relapse. In addition, estramustine phosphate was also shown to cause shrinkage in the tumor volume.

Cell kinetic studies of prostatic cancer: adjuvant therapy in animal models

Cell kinetic studies have been applied to the rat prostatic cancer R-3327-AT. This transplantable anaplastic tumor has a rapid growth rate and doubles its volume every 2.17 days. Cell kinetic considerations have been used to design a therapeutic approach which is capable of curing animals carrying this tumor, or providing long periods of complete remission. This treatment approach involves chemotherapy followed by surgery and immuno-stimulation with pyran copolymer. Such adjuvant tumor therapy is most effective against a small tumor load. The application of cell kinetic considerations to the control of human prostatic cancer is discussed.

Diagnosis and pathophysiology of paradoxical embolism

Three cases of paradoxical embolism are presented. Although most systemic emboli originate in the heart, detection of other sources is aided by venography of the lower extremities, indocyanine green-dye curve studies of the inferior vena cava, obtaining right heart pressures, oximetry, and pulmonary angiography. Forty per cent of 55 patients reviewed had repeat episodes of systemic embolism and 2 of the 3 proved cases of paradoxical embolism had repeat episodes. Prolonged anticoagulant therapy may prevent recurrence.

Prostatic carcinoma. relationship between primary tumor, histologic grade, and response to chemotherapy

This National Cooperative Study has randomly compared the usefulness of 5-fluorouracil (5-FU), cyclophosphamide (Cytoxan) and standard therapy in patients with advanced carcinoma of the prostate (Stage D). All patients studied were endocrine failures and were in progression. Favorable responses were seen with all three treatments regardless of histologic grade. Actual tumor regression occurred only in patients who received either 5-FU or cyclophosphamide. In patients with poorly differentiated or anaplastic tumors treated with cyclophosphamide, progression of disease was significantly less rapid than in patients treated with 5-FU or standard therapy. However, favorable responders could not always be identified in advance on the basis of histologic grade alone.

Clinical significance of serum acid phosphatase levels in advanced prostatic carcinoma

This cooperative study was sponsored by the National Prostatic Cancer Project to determine the usefulness of serum acid phosphatase levels as a predictive indicator with regard to performance status, sites of metastases, response to treatment, and survival in patients with advanced prostatic carcinoma. The results indicate that survival was significantly shorter for those patients who had elevation of thier on-study (pretreatment) total serum acid phosphatase ler cent reduction of primary tumor mass, relief of pain, and acid phosphatase activity. No correlation could be demonstrated between serum acid phosphatase and performance status, site of metastases, and other criteria of response to therapy. It is concluded that this test as currently determined spectrophotometrically at this stage of disease and if employed alone is not sufficient to allow for total evaluation of the response of therapy. It is, however, helpful when used in correlation with the previously mentioned positive factors.

The continued evaluation of the effects of chemotherapy in patients with advanced carcinoma of the prostate

The response and duration of survival were evaluated for patients with stage D relapsing prostatic cancer who were randomized to cyclophosphamide (cytoxan), 5-fluorouracil (5-FU) or standard therapy, or to subsequent chemotherapies. The chemotherapies on initial randomization were superior to the standard therapy in the number of responders and duration of response. Survival was longer for responders (stable or partial regression) on chemotherapy by comparison to responders (stable only) on standard therapy. The survival for patients receiving initial and crossover chemotherapy was significantly improved for patients who responded to therapy. Chemotherapy of advanced relapsing stage D prostatic cancer is more beneficially treated by specific chemotherapy as shown in this randomized study.

Chemotherapy of advanced prostatic cancer. Evaluation of response parameters

A total of 125 patients with progressing advanced prostatic cancer were entered into a chemotherapy study comparing cyclophosphamide, 5-fluorouracil, and standard therapy. Parameters of response were studied in 110 patients who could be evaluated. Thirty-six patients (33 per cent) were considered to have an objective response, that is becoming stable (29 patients) or in partial regression (7 patients). Negative response parameters (predictors of a poor response to chemotherapy or standard theraphy leading to progress) included (1) bone marrow evidence of prostatic cancer, (2) abnormal liver scan, (3) prior radiation therapy (indirectly through increased toxicity to chemotherapy), and (4) lack of bilateral orchiectomy prior to randomization. Positive indicators (predictors of good responses) included (1) reduction of primary tumor mass, especially after administration of 5-fluorouracil or cyclophosphamide, and (2) hemoglobin values. There were more objective responders to cyclophosphamide than standard therapy whether the hemoglobin was initially normal or low. Indeterminate parameters of response included weight gain, presence of bony or soft tissue metastases, relief of pain, performance status, excretory urography, and biochemical determinations of liver and renal function.

Chemotherapy of advanced prostatic carcinoma with cyclophosphamide or 5-fluorouracil: results of first national randomized study

The National Prostatic Cancer Project has randomized this study for endocrine-resistant prostatic cancer patients for treatment with standard hormonal or other therapies compared to 5-fluorouracil and cyclophosphamide. Both agents were found at the probability level of 0.05 to have a significant advantage over standard treatment in terms of objective response, subjective improvement and minimal toxicity. Additional chemotherapy protocols are currently under way. This randomized trial is the first report of such a national study completed to date. We are much encouraged by this program and believe that additional agents now under consideration will provide additionally encouraging results.

The effects of 5-fluorouracil on prostatic DNA synthesis

A new animal model has been developed for studying the effects of nonhormonal drugs on the androgen-induced growth of the rat prostate. The antimetabolite 5-fluorouracil caused a 60 per cent reduction of the rate of prostatic DNA synthesis in androgen-stimulated castrate rats. This drug did not decrease the size of the prostate in normal intact animals and did not exhibit significant antiandrogenic activity. Its distribution is primarily in the acid-soluble fraction of the total prostatic homogenate.

Concepts and limitations in the application of radiolabeled antiandrogens, estrogens, or androgens as isotopic scanning agents for the prostate

The distribution of labeled antiandrogens, estrogens, and androgens has been studied in the rat and dog to elucidate the principles and limitations encountered when these agents are used in radioscanning the prostate. The bulk of the label is rapidly cleared in the biliary secretions and in the urine. The concentration of label in the prostate in comparison to other tissues such as the intestines limits the application of these agents in radioscanning of the prostate. The tissue distributions were confirmed by total body radioscans of rats and dogs receiving a labeled 3'-iodinated analog of the antiandrogen flutamide (Sch 13521 or 3'-trifluoromethyl-4'-nitroisobutyranilide).

Evaluation of a magnetic bladder pump for neurogenic bladders

A new bladder pump prosthesis has been designed and evaluated in the normal dog bladder. This encompasses a magnetic pump located subcutaneously with internal silicone catheters from bladder to the urethra. The pump is powered from a hand-held activator which is magnetically coupled externally across the skin. This pump was evaluated in 12 dogs for an average of 65 days and provided adequate emptying of the bladder without alteration of the normal urinary tract or pump malfunction. The potential and limitations of this new approach are discussed.