Newer products and formulas for alimentation.

Adequate nutritional support for the critically ill patient has evolved over the past 150 years from a time when starvation was accepted practice for patients with fever. Three to four thousand calories and other essential nutrients can now be safely provided each day to patients with infection or other critical illness. Nutrients may be provided in meals, administered by specialized enteral feedings, or infused intravenously. Nutrient mixtures with a high proportion of carbohydrate and protein appear the best dietary therapy to maintain body protein and support other organ systems and and cellular functions. New products and formulas offer the physician a wide variety of techniques for providing adequate nutrition to all patients with critical illness.

The pathophysiology of hyperchloremic metabolic acidosis after urinary diversion through intestinal segments.

The pathophysiology of hyperchloremic metabolic acidosis after urinary diversion through intestinal segments has not been defined. This study employs a canine model in which an ileal segment is interposed between one kidney and the urinary bladder. Comparison of urinary solute excretion rates between the normal and interposed renal units allows quantitation of solute reabsorption and secretion by the ileal segment. Ileal segments reabsorb urinary chloride, potassium, and ammonium. Ammonium is reabsorbed in part as its conjugate free base, ammonia, with the liberated hydrogen ion reabsorbed with chloride or excreted as titratable acid. Inability to excrete acid as ammonium results in depletion of body buffers and a diminished capacity to compensate an additional acid challenge. Bicarbonate is secreted by the ileal segments but not in amounts that are physiologically significant. Impaired renal function predisposes to the development of this syndrome but is not a primary pathophysiologic mechanism.

The effect of exogenous substrate on hepatic metabolism and membrand transport during endotoxemia.

Endotoxemia in dogs reduced hepatic uptake and biliary excretion of indocyanine green dye. This diminished active membrane transport was associated with reduced hepatocyte membrane potential difference. Studies of arteriovenous concentration differences and flow across the liver demonstrated that endotoxemia increased hepatic glucose and lactate production and decreased oxygen consumption. Correction of this energy deficit occurred following infusion of glucose and insulin, but not after administration of isocaloric quantities of intravenous amino acids. The glucose-insulin infusion during endotoxemia shifted the liver back to an organ of glucose uptake, improved oxygen consumption, and provided the necessary energy for normal dye transport and maintenance of the normal membrane potential difference.

Cavoatrial tumor thrombectomy using cardiopulmonary bypass without circulatory arrest.

Of 29 patients with inferior vena caval tumor thrombus, 14 with supradiaphragmatic extension were deemed suitable for operation. Patients (age, 7.5 to 70 years) had renal cell carcinoma (n = 8), Wilms' tumor (n = 2), transitional cell carcinoma (n = 1), and adrenal carcinoma (n = 3). Seven patients had stage III disease, and 7 patients had stage IV disease. Two patients (group A) had unresectable disease at exploratory celiotomy, 4 patients (group B) underwent tumor thrombectomy without cardiopulmonary bypass, and cardiopulmonary bypass was employed in 8 patients (group C). Three of 8 group C patients had Budd-Chiari syndrome at diagnosis. Cardiopulmonary bypass with moderate hypothermia, and inferior vena caval interruption (clip or filter), was employed in all patients. There were no perioperative deaths. Transient neurological impairment was observed postoperatively in 2 patients. Coagulopathy developed in 1 patient who had hepatic encephalopathy and Budd-Chiari syndrome preoperatively and in another patient in whom protamine could not be administered. No patient had acute renal failure requiring hemodialysis. Median survival is 41 and 17 months in groups B and C, respectively. Some authors have advocated profound hypothermia and circulatory arrest in these patients. We find that satisfactory visualization and excision can be performed with cardiopulmonary bypass and moderate hypothermia, avoiding potential renal, hepatic, neurological, and septic complications associated with circulatory arrest.

Transureteroureterostomy: an adjunct to cystectomy.

Eight elderly patients with carcinoma of the bladder have been managed over the last three years with cystectomy done along with transureteroureterostomy. The decision for surgery was dictated by intractable bleeding, disabling symptoms, and extensive recurrent lesions of life-threatening degree. All of these patients were a poor risk. All successfully had cystectomy with urinary diversions achieved by transureteroureterostomies in association with a cutaneous ureterostomy. The surgery was done extraperitoneally; the patients were usually ambulated quickly, and the need for long-term nasogastric tubes was obviated. The course and clinical management of these patients are discussed and advantages and disadvantages of this form of urinary diversion presented.

Complications of low-dose heparin prophylaxis following pelvic lymphadenectomy.

All patients who underwent pelvic lymphadenectomy for prostatic carcinoma over a five-year period were reviewed to evaluate the effect of minidose heparin prophylaxis on lymphocele formation and postoperative complications. The overall incidence of complications was found to be consistent with that reported in the current literature. However, when the rate of lymphocele occurrence was correlated with perioperative minidose heparin therapy, the incidence rose from 2.5 per cent in those receiving no heparin to 38 per cent in patients receiving both pre- and postoperative prophylactic heparinization. Other major postoperative complications were also significantly increased when minidose heparin was pre- or postoperatively administered. A strong recommendation is made for caution in the routine use of prophylactic low-dose heparin during pelvic surgery.

Laser-induced hyperthermia in rat prostate cancer: role of site of tumor implantation.

OBJECTIVES: To investigate the importance of the site of tumor implantation on the treatment response to laser-induced hyperthermia (LIH) of rat prostate cancer (PCa), because interventional manipulations of PCa have been reported to increase metastatic dissemination. METHODS: Seven to nine days after either subcutaneous or orthotopic implantation of MatLyLu cells, LIH (46.5 degrees C) was induced using pulsed irradiations of a neodymium:yttrium-aluminum-garnet laser. Both local control and distant metastases were evaluated. Plasma metalloproteinase 9 (MMP-9) was tested as a possible marker of PCa progression and LIH response. RESULTS: Twelve days after LIH treatment of subcutaneous tumors, the volumes were reduced by 64% after 8 minutes of irradiation, 73% after 10 minutes, 81% after 15 minutes, and 91.1% after 20 minutes. In the orthotopic model, the corresponding tumor reductions were 44% after 10 minutes, 61% after 20 minutes, and 65% after 30 minutes. Lung metastases were observed in only 1 animal with subcutaneous tumors. In contrast, 86% of the orthotopic tumor-bearing animals treated for 30 minutes had lung metastases compared with 23% of the untreated tumor-bearing rats. MMP-9 expression was detected in both orthotopic and subcutaneous tumor tissue and in the plasma of tumor-bearing rats. The prostate tissue of healthy rats and subcutaneous tumor-bearing rats was devoid of MMP-9. The plasma levels of MMP-9 showed a trend toward direct correlation with local tumor control but no correlation with the incidence of metastasis. CONCLUSIONS: These data emphasize the importance of the site of tumor implantation for evaluation of the efficacy of therapeutic interventions and may warrant further studies before widespread clinical application of LIH as monotherapy.

Intestinal ammonium transport by ammonium and hydrogen exchange.

BACKGROUND: Ionized ammonia (NH3) transport in the intestine has not been previously established as a mechanism of acidosis in urinary intestinal diversion or hepatic failure. STUDY DESIGN: The purpose of this study was to establish that ionized transport of ammonium (NH4) occurs in the intestine and to characterize the mechanism of its transport using the methodology of brush border membrane vesicles and acridine orange fluorescence. RESULTS: An NH4/H exchange was demonstrated and found to be the dominant mechanism causing a pH change when NH4 is transported across the lumenal membrane. Ionized NH4 transport was demonstrated to occur against an NH3 concentration gradient. The Km was 1.02 mmol and the Vmax was 247 U/sec. The Hill coefficient was 0.97, indicating a single port. Ammonium hydrogen exchange could be inhibited by amiloride but not by bumetanide. Sodium, potassium or chloride, or both, did not effect the NH4/H exchanger. CONCLUSIONS: This study establishes that ionized NH4 transport occurs across the small intestine brush border in exchange for a hydrogen ion.

Utility of nuclear matrix protein (NMP22) in the detection of recurrent bladder cancer.

This article examines the Nuclear Matrix Protein (NMP22) urine test for recurrent bladder cancer detection. Studies with NMP22 are compared to cytology for sensitivity and specificity. False positives and false negatives do occur, and consequences of these are discussed. Speculations are made regarding possible future uses of this test.

Metabolic consequences of urinary diversion through intestinal segments.

The use of intestinal segments in the reconstruction of the urinary tract for a variety of malignant and nonmalignant conditions is generally accepted. Metabolic derangements may result any time urine is in contact with the intestinal mucosa. Numerous studies concerning the pathophysiology of this syndrome have demonstrated that it is in large part secondary to reabsorption of urinary acid as ammonium and, to a lesser degree, to bicarbonate secretion into the urine. The syndrome of metabolic acidosis resulting from urinary diversion has been most common after ureterosigmoidostomy, often in the setting of renal insufficiency secondary to pyelonephritis and obstruction. It became a lesser clinical problem with the popularization and frequent use of conduit urinary diversions. At present, with a greater emphasis on the construction of large-capacity continent urinary diversions, there is an increased likelihood of metabolic derangements, especially in the setting of renal insufficiency. Furthermore, although the reported incidence of clinically problematic metabolic derangements is low with the newer modes of continent urinary diversion, it is impossible to assess the significance of a mild or asymptomatic acidosis, which may occur even in the setting of normal serum electrolytes. Only with close long-term follow-up can the significance of this change be determined.

The use of in bowel urology. Metabolic and nutritional complications.

Metabolic and nutritional complications of urinary diversion through bowel or stomach segments are common, but fortunately, not often severe. When metabolic abnormalities are problematic, deterioration or baseline insufficiency in renal function is the most likely cause. Deterioration is most commonly associated with obstruction or infection. The urologist should be acutely aware of the potential for metabolic derangements when the prediversion creatinine is greater than 2.0 mg/dL. In this situation, the urologist should employ the basic principles in this article when planning the procedure in order to minimize metabolic complications and morbidities. In the setting of significant renal insufficiency, a short colon or ileal conduit would likely be superior to an ileal or colonic neobladder, or a diversion, incorporating a large gastric segment. Furthermore, in the absence of symptomatic metabolic abnormalities, we advocate treatment of minor laboratory abnormalities, particularly acidosis, to reduce the incidence of metabolic bone disease. Nutritional and gastrointestinal complications are treated on an "as needed" basis, with the exception of metabolic bone disease, which we would hope to prevent with alkalinization and Vitamin C supplementation. Some of the nutritional and gastrointestinal complications are best avoided by leaving the ileocecal valve intact, or by minimizing the use of certain segments. Some evidence exists that over time, histologic changes in the epithelium of diversion segments may impair absorption and contribute to greater resistance against metabolic derangements. Whether the changes truly reduce the incidence of metabolic abnormalities remains to be studied. The ideal, complication-free, diversion with universal application does not exist; however, the urologist must strive to select an option that will provide a functional result for the patient with minimal associated morbidity.

Penile carcinoma: the case for primary lymphadenectomy.

In the preceding sections, the authors have presented an approach to the management of patients with squamous-cell carcinoma of the penis selected to maximize the therapeutic benefits in high-risk patients while minimizing morbidity in low-risk patients. A clinical staging system is presented in order to approach this problem in a logical fashion. Patients with stage I penile carcinomas are all managed by eradication of the primary lesion followed by expectant management of the inguinal lymph nodes. Persistent inguinal adenopathy after treatment of the primary lesion has been a very rare occurrence in this group of patients in our experience. Patients with stage II penile carcinoma are managed by eradication of the primary lesion, 6-8 weeks of antibiotic therapy, and inguinal lymphadenectomy. The available literature suggests a high incidence of inguinal lymphatic metastases in this group of patients and supports the need for early lymphadenectomy. Finally, patients with clinical stage III disease, i.e., persistent adenopathy after eradication of the primary lesion and 6-8 weeks of antibiotic therapy, all undergo inguinal lymphadenectomy. This group is at extremely high risk and does poorly without aggressive surgical management.

Studies on the differentiation pathway and growth characteristics of epithelial culture cells of the human prostate.

We established explant primary cultures in order to study the growth and hormone responsiveness, and the differentiation process of prostatic epithelial cells. Cell outgrowth was achieved from explant tissue by using a new DU145-cell-conditioned medium and special plastic coverslips. To define the present model, proliferation assays were tested by [3H]thymidine assay and planimetric analysis. Cells were analyzed using immunocytochemistry, light, phase contrast and electron microscopy, polymerase chain reaction, telomerase ELISA and immunoassay (PSA). Morphology and electron microscopy revealed typical epithelial differentiation. Immunocytochemistry showed the content of basal and secretory epithelial cells, endocrine paracrine cells and a high level of proliferation. With increasing culture time, mature epithelial differentiation (PSA) increases and the initial increase of alpha-smooth muscle actin (alpha-SMA) decreases again. After further passaging, alpha-SMA expression is no longer detected and PSA expression decreases. Furthermore, epithelial cells showed both androgen responsiveness and androgen receptor expression. These findings show the presence of epithelial cells in a process of differentiation with endocrine paracrine cells and a high level of proliferation. This model may maintain the cellular and functional properties more closely related to the human prostate and may provide a valuable tool for studying stem cells and differentiation characteristics.

Urologic causes of the acute abdomen.

This article reviews renal and perirenal infections, obstructing conditions of the renal pelvis and ureter, and acute intrascrotal events. Each subject is reviewed with regard to patterns of presentation, means of diagnosis, and treatment options. Emphasis is placed on new modalities in the evaluation and treatment of these conditions.

Abdominal complications of collagen vascular disease.

A retrospective study of 412 consecutive hospital admissions of patients with collagen vascular disease yielded 63 patients who were admitted for abdominal complaints. Of these 63 patients, 11 died during their admission of primary intra-abdominal pathology or a complication thereof. A significantly higher incidence of abdominal complications occurred in black women (P less than 0.01). Peritoneal signs invariably were lacking in patients who eventually died. Radiographic documentation of small bowel obstruction or gastroduodenal ulceration in these patients was particularly ominous. Rapid radiologic evaluation and early surgical intervention including diagnostic peritoneal lavage should decrease the mortality rate for these difficult patients.

A new model to study acute and chronic renal failure.

Many models have been developed to study renal function following injury. Two types of studies have evolved: acute--to define the acute renal injury and chronic--to determine the pattern of recovery. Current models allow either study alone to be performed, but they lack the flexibility to combine the studies. In this study of renal ischemia, a model was designed which solved this problem. The authors constructed a model for performing a unilateral nephrectomy and episiotomy on female dogs. Catheters were placed in the renal vein, vena cava, and aorta, and a renal artery flow cuff was applied. The catheters and wires were buried in a subcutaneous pocket and were exteriorized after a recovery of several weeks. The episiotomy allowed easy intermittent Foley catheterization. With the animals awake and in a harness, parameters of renal function were measured: renal extraction, filtration fraction, fractional excretion, osmolar clearance, and free water clearance. Glomerular filtration rate and renal plasma flow were calculated by inulin and paramino hippurate clearances. The animals were studied in diuretic and antidiuretic states. In addition, renal artery flow was determined by the Doppler flow cuff. All parameters were determined every half hour in the acute setting, then every day in the chronic setting. The model was easily reproducible and functioned well in the authors' renal ischemia studies. Initial experiments with 1 hour of warm ischemia produced a greater than 50 per cent reduction in GFR acutely. Chronic studies showed a GFR with a return toward normal. All model construction purposes and plans were met.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessing prostate cancer growth with citrate measured by intact tissue proton magnetic resonance spectroscopy.

BACKGROUND: Annual PSA tests have led to a significant increase in the number of prostate cancer (PCa) cases diagnosed. This increased incidence has led to overtreatment of many patients, as current pathology often cannot distinguish latent from aggressive PCa. Studies have shown that the depletion of zinc in prostate cells correlated with cell-line growth rates, and may therefore relate to the progression of PCa. Furthermore, as zinc is normally an inhibitor of citrate oxidation, the reduction of zinc in PCa may cause a decrease in citrate secretion levels in the glandular epithelia of PCa patients. METHODS: Using high-resolution magic angle spinning proton magnetic resonance spectroscopy followed by quantitative histopathology, we investigate unit histo-benign prostate epithelial citrate concentrations in intact tissue samples obtained from 18 patients with pre-surgical PSA values less than 20 ng/ml. Using these data, we evaluate correlations between citrate concentrations and PSA velocities, densities and blood percent-free PSA. RESULTS: We observe different linear patterns between citrate concentrations and histo-benign glandular epithelia from patients of different PSA velocities. More importantly, we obtain a significant correlation between PSA velocity, density and percent-free PSA, and citrate concentrations in unit volume of histo-benign epithelial glands of the peripheral zone. CONCLUSIONS: Low levels of citrate in unit volume represent rapidly increasing PSA values, and, therefore, may be used as an indicator of fast-growing PCa. Thus, tissue samples obtained at the time of biopsy may be evaluated for their citrate concentrations for the prediction of PCa growth rates, allowing for the implementation of alternative treatment options and reducing overtreatment.