Assessing renal effects and renal protection

ASSESSMENT OF RENAL FUNCTION: There are a number of methods of evaluating renal function, including measurements of glomerular filtration, renal plasma flow, tubular function, micro- and macroalbuminuria and urinary sediment. Of these, microalbuminuria, glomerular filtration and renal plasma flow are the most appropriate. RENAL EFFECTS OF CALCIUM ANTAGONISTS: Calcium antagonists have important effects on renal function, including a reduction in renal vasoconstriction, increased renal blood flow and, in some circumstances, reduced protein excretion. In particular, these agents can reverse the mild renal vasoconstriction that is seen in the offspring of hypertensive patients. The renal effects of calcium antagonists have been studied in animal models, where radioimaging techniques have shown a biphasic haemodynamic response. RENAL PROTECTION WITH CALCIUM ANTAGONISTS: Two important beneficial effects of calcium antagonists are prevention of acute renal failure and protection against cyclosporin nephrotoxicity. Calcium antagonists have thus been used therapeutically in renal transplant patients and in patients with acute renal failure secondary to the effects of nephrotoxic agents.     

Spontaneous renal hemorrhage associated with renal tumors

Authors underline the neuropeptides function in the arising of the allergic modulation: the relationship between eNANC-iNANC systems, their mediators and the production of cytokines and immunoglobulins. The above demonstrates that the peptidergic system has a primary role in the complex pathogenetic mechanism of the allergic asthma.     

Orthostatic acute renal failure in a renal transplant

Complications due to ureteric obstruction are an occasional cause for renal transplant dysfunction. Here we report an unusual case of orthostatic renal failure in a renal transplant recipient. Our patient had the previously reported predisposing risk factors including: female sex, obesity, and lax abdominal musculature. It is important to recognize this unusual complication of renal transplantation early in order to preserve long-term graft function.     

Medial fibroplasia: involvement of renal artery and small renal arteries in renal vascular hypertension

Dysplasia of the renal artery may cause renal vascular hypertension. The most common type of dysplasia is the medial fibroplasia. Medial fibroplasia, as well as the other types of dysplasia, has only been described in the main and primary branches of the renal artery. A case of medial fibroplasia, where arterial changes were seen far out in the small renal vessels is reported.     

Acute renal insufficiency in hemorrhagic fever with renal syndrome

PURPOSE: Propranolol, a beta-adrenergic antagonist, has been shown to block hyperthermically-induced ocular recurrence of HSV-1 in mice and reduce spontaneous ocular viral shedding and herpetic corneal lesions in latently infected rabbits. The present study was performed to determine the effect of propranolol on epinephrine iontophoresis-induced ocular recurrence and immunosuppression-induced ocular recurrence in the rabbit eye model. METHODS: New Zealand white rabbits were infected with HSV-1 strain 17Syn+ or McKrae. After latency was established, the animals were injected intramuscularly with saline (placebo), or propranolol (5-200 mg/kg) twice daily, and then induced with epinephrine iontophoresis or cyclophosphamide and dexamethasone administration. Tear film swabs were cultured to determine the frequency of viral shedding. RESULTS: Propranolol administered at a range of doses did not affect the frequency or duration of viral shedding following epinephrine or cyclophosphamide/dexamethasone induction as compared to saline treatment. CONCLUSION: These results demonstrate that propranolol does not significantly reduce ocular HSV-1 shedding following induction by epinephrine iontophoresis or immunosuppression. By inference, these results suggest two possibilities: (1) that viral pathways leading to spontaneous and induced shedding of virus are under separate control mechanisms or (2) in rabbits, these inducers are of such potency that propranolol is ineffectual.     

Enalapril-induced renal artery thrombosis in unilateral renal artery stenosis

Intravascular adhesion of leucocytes plays a role in the pathogenesis of acute and chronic vascular disease. Regular aerobic exercise seems to protect against vascular disease. Since leucocyte adhesion is mediated by integrins, we tested the hypothesis that surface expression of the integrin adhesive receptors LFA-1 (cd11a/cd18), MAC-1 (cd11b/cd18), gp 150/95 (cd11c/cd18), and VLA-4 (cd29/cd49) is decreased by moderate endurance exercise. Surface expression of integrins was measured by FACS analysis in 19 healthy subjects (16 males, 3 females, 36.6 +/- 8.7 years, 177.1 +/- 7.5 cm, 70.3 +/- 8.1 kg) before and after submaximal exercise (3 h run) using monoclonal antibodies against cd11a, cd11b, cd11c, cd18, cd29 and cd49. In addition, we compared resting integrin expression in this group with a group of sedentary subjects (19 males, 6 females, 29.3 +/- 5.3 years). White blood cell count increased from 5300 ml(-1) to 9740 ml(-1) during exercise (P < 0.001). Nevertheless, the expression (indicated by the mean log fluorescence) of cd11a (94 +/- 24 vs. 78 +/- 14) and cd18 (128 +/- 31 vs. 102 +/- 21) on lymphocytes and of cd11a (104 +/- 25 vs. 85 +/- 16), cd11c (497 +/- 171 vs. 408 +/- 126) cd29 (109 +/- 16 vs. 89 +/- 16), cd49 (69 +/- 8 vs. 54 +/- 11) on monocytes was decreased after exercise (all P < 0.05). In contrast, integrin expression on granulocytes was not altered by exercise. Comparison of exercising and sedentary subjects showed a significantly decreased expression of integrins in exercising subjects. Our results demonstrate that moderate exercise leads to decreased expression of integrin receptors on leucocytes. This decreased expression of adhesion molecules may result in decreased adhesion and infiltration of leucocytes into the vessel wall. This phenomenon may play a role in the beneficial effect of moderate exercise in prevention of acute and chronic vascular disease.     

Medullary renal dysplasia mimicking renal tumor in the Beckwith-Wiedemann syndrome

The known association of Wilms' tumor with the Beckwith-Wiedemann syndrome has prompted a surveillance regimen for children with this problem. Herein we report a case of medullary renal dysplasia that was a new onset by documented ultrasound. The association of medullary renal dysplasia with Beckwith-Wiedemann syndrome is discussed as well as the management of this problem.     

Sarcomatoid renal carcinoma

OBJECTIVE: Sarcomatoid carcinoma of the kidney is a unique, uncommon variety of parenchymatous tumors and is considered to have a worse prognosis by stage than the other histological types. Our experience is reviewed and compared with the larger series reported in the literature. METHODS: Of 101 cases of renal carcinoma submitted to surgery at our department from January, 1990 to December, 1996, there were 4 cases of sarcomatoid carcinoma of the kidney. We compared our cases with the larger series (91 cases in total) reported in the literature for incidence, age, distribution according to sex, tumor size, location, form of presentation, stage and survival. RESULTS: Sarcomatoid renal carcinoma accounts for 1% to 6% of parenchymatous tumors of the kidney according to the different series. The mean age at presentation was 48 years (range 27-61) in our series; there was no prevalence according to sex or location; the renal capsule was not compromised in 3 out of the 4 cases; only one case showed regional lymph node involvement and no case showed distant metastasis at the time of diagnosis. Although these tumors are diagnosed in the advanced stages, two of our cases were incidentally discovered in the early stages (one died 13 months thereafter and the other is alive at 42 months). Patients that are alive and disease-free can only be found in the patient group with stage I or II tumor. All patients with tumor stage III and IV have died. This histological type has a worse prognosis. Most of the series report a mean survival of 5 months. CONCLUSIONS: Sarcomatoid renal carcinoma accounts for 1%-6% of all renal carcinomas. It can present at any age and has a very poor prognosis, with a mean survival of 6 months.     

Primary renal mucormycosis

Cell adhesion to the extracellular matrix appears to trigger a cascade of intracellular signalings. We have shown previously that treatment of ovarian cancer cells with peritoneal conditioned medium or purified fibronectin (FN) activated matrix metalloproteinase 9 secretion and, thereby, cancer cell invasion. By use of antisense oligonucleotides to focal adhesion kinase (FAK) and a dominant-negative mutant of ras (S17Nras), we found that both FAK and c-Ras were required for the activation of matrix metalloproteinase 9 secretion by FN. In addition, both antisense oligonucleotides to FAK and S17Nras inhibited mitogen-activated protein kinase activation by FN treatment, suggesting the involvement of mitogen-activated protein kinase in the FN-dependent signaling.     

Metastasis of renal cell carcinoma to the contralateral renal pelvis

A young woman with syphilids resembling borderline lepromatous (BL) leprosy is being described. This is yet another addition to its already well-documented manifestations. The high prevalence of leprosy and syphilis augments the epidemiological significance of the case.     

AIDS-associated renal tuberculosis

In order to study the prevalence and the clinical features of renal tuberculosis associated with AIDS, we studied the renal tissue of the necropsies made in 46 AIDS patients under light microscopy. We found renal tuberculous granuloma in 11 (23%) patients (in 3 without previous diagnosis of renal or extrarenal tuberculosis) and only 4 of them presented moderate hematuria or pyuria sterile. As subclinical renal tuberculosis was frequent in this group of AIDS patients, the urine culture for Mycobacterium tuberculosis may be useful for diagnosing tuberculosis in AIDS patients.     

Pediatric renal tumors

A broad spectrum of renal tumors occurs in infants and children ranging from the benign cystic nephroma to the extremely aggressive malignant rhabdoid tumor of the kidney. A thorough understanding of these tumors is crucial to the optimal diagnosis and management of children with renal masses. The common renal tumors in infants and children are discussed and an orderly method for their evaluation is presented. Recent developments in the molecular biology of Wilms' tumor are outlined to provide insight into the origin of this tumor.     

Acute renal insufficiency

The incidence of acute renal failure in children is higher due to the prevalence of diarrheal dehydration, use of nephrotoxic substances and sepsis. The occurrence in the newborn has increased, probably due to the large number of seriously sick infants maintained in neonatal intensive care units. Various laboratory examinations have been proposed as diagnostic indices of acute renal failure in children. Among these are the urine-to-plasma concentrations of urea and creatinine and the urine-to-plasma osmolality ratio. The fractional excretion of sodium and the so-called renal failure index are the most reliable of the diagnostic tests. The functional abnormalities and complications of acute renal failure include reduced glomerular filtration rate, retention of nitrogenous wastes, hyponatremia, hyperkalemia, metabolic acidosis, hypocalcemia, hyperphosphatemia and hypermagnesemia. The principles of management and treatment of complications are discussed.     

Closed renal trauma

A series of 76 cases of closed renal trauma is presented. The clinical and radiological features are described and the indications for conservative and surgical treatment discussed.     

Bilateral renal tumors

At the Urological Clinic in Hradec Králové in 1990-1994 320 patients with renal tumours were admitted and treated. In 12 the tumour was bilateral (3.7%), incl. 8 patients where it was synchronous and four where it was asynchronous. Only in one female patient bilateral nephrectomy was performed, in 8 patients unilateral nephrectomy and on the other side enucleation of the tumour, in two patients bilateral enucleation of the tumour and in one patient with a malignant lymphoblastic lymphoma only unilateral enucleation of the tumour and epinephrectomy. In 10 patients histological examination confirmed a renal carcinoma, in one patient a malignant lymphoblastic lymphoma, in one female patient a bilateral multifocal oncocytoma. The patients survival was not evaluated in the report.     

Neonatal renal candidiasis

A case is presented of renal candidiasis complicated by obstructive uropathy in a 4 month old infant. Management was successful with surgical decompression combined with peri-operative amphotericin B, followed by 3 weeks of oral ketoconazole and subsequently 6 weeks of oral fluconazole. Fluconazole was substituted for ketoconazole owing to persistent candiduria, and achieved rapid urinary sterilization. Fluconazole is an effective and less toxic alternative to prolonged courses of amphotericin B in the treatment of neonatal renal candidiasis.