Demonstration of exclusive cilioretinal vascular system supplying the retina in man: vacant discs.
(49/7998)
PURPOSE: To report the fluorescein angiographic and Doppler ultrasonographic findings in a patient with apparent exclusive ciliary vascular supply of the retina of both eyes. METHODS: Case report. RESULTS: The ophthalmoscopic appearance of all arterial vessels emanating from both discs was consistent with a cilioretinal origin. Retinal veins also entered each disc peripherally near the margin, leaving the central part of each disc vacant. Fluorescein angiography showed filling of all arterial vessels simultaneous with the early-phase choroidal background flush bilaterally. Color and power Doppler ultrasonographic imaging demonstrated unequivocally the absence of central retinal vessels within the optic nerves. Both discs were normal in size and excavated with central glial tissue present. The clinical history of monocular, alternating episodes of failing vision with partial resolution and the retinal pigmentation patterns bilaterally were consistent with, though not conclusive for, previous episodes of serous retinal detachments. Coincident systemic anomalies consisted of small kidneys with reduced renal parenchyma discovered on ultrasonography, along with chronic interstitial nephritis. CONCLUSIONS: The ophthalmoscopic appearance of optic discs with apparent all-cilioretinal vascular supply has been reported previously, but proof of the absence of central retinal vessels requires Doppler ultrasonographic evidence corroborated by angiographic findings, as exemplified in our case report. We describe the association of this disc anomaly with renal parenchymal disease and its distinction from colobomatous defects. (+info)
MEFV-Gene analysis in armenian patients with Familial Mediterranean fever: diagnostic value and unfavorable renal prognosis of the M694V homozygous genotype-genetic and therapeutic implications.
(50/7998)
Familial Mediterranean fever (FMF) is a recessively inherited disorder that is common in patients of Armenian ancestry. To date, its diagnosis, which can be made only retrospectively, is one of exclusion, based entirely on nonspecific clinical signs that result from serosal inflammation and that may lead to unnecessary surgery. Renal amyloidosis, prevented by colchicine, is the most severe complication of FMF, a disorder associated with mutations in the MEFV gene. To evaluate the diagnostic and prognostic value of MEFV-gene analysis, we investigated 90 Armenian FMF patients from 77 unrelated families that were not selected through genetic-linkage analysis. Eight mutations, one of which (R408Q) is new, were found to account for 93% of the 163 independent FMF alleles, with both FMF alleles identified in 89% of the patients. In several instances, family studies provided molecular evidence for pseudodominant transmission and incomplete penetrance of the disease phenotype. The M694V homozygous genotype was found to be associated with a higher prevalence of renal amyloidosis and arthritis, compared with other genotypes (P=.0002 and P=.006, respectively). The demonstration of both the diagnostic and prognostic value of MEFV analysis and particular modes of inheritance should lead to new ways for management of FMF-including genetic counseling and therapeutic decisions in affected families. (+info)
Congenital renal dysplasia and psychogenic polydipsia in a Bernese mountain dog.
(51/7998)
Congenital renal dysplasia was tentatively diagnosed, based on ultrasound and an intravenous urogram, in a 5-month-old female with polyuria and polydipsia. Creatinine clearance measurement revealed that the renal dysplasia was not the cause of the polyuria. A modified water deprivation test eliminated other differential diagnoses and confirmed psychogenic polydipsia. (+info)
Lesions and identification of crystalline precipitates of glycoprotein IIb-IIIa antagonists in the rat kidney.
(52/7998)
Two glycoprotein IIb-IIIa antagonists (xemilofiban, SC-54684A, and orbofiban, SC-57099B), which are platelet aggregation inhibitors, caused crystalline precipitates in the kidney tubules of rats at high dosages. Dogs were not affected. Depending on the degree of the precipitation, which was dosage dependent, and the location, which differed somewhat between the two compounds, the lesions varied from acute obstruction with tubule cell necrosis, nephron dilation, and sudden death with no inflammation to severe chronic pyogranulomatous inflammation. In order to understand the relevance of the lesions, it was important to identify the precipitates. This was technically challenging because the crystals were water soluble (dissolving in routine fixing and staining techniques) and were present in insufficient quantity to physically isolate. Techniques were devised to evaluate the crystals in situ in unstained frozen sections prepared without directly embedding the tissues in supporting medium, which interfered with the analyses. The crystals were analyzed in situ by infrared and Raman spectroscopy and time-of-flight secondary ion mass spectroscopy (TOF-SIMS). Uroliths found in the renal pelvis of one animal were analyzed by liquid chromatography/mass spectrometry. The resulting spectra showed that the crystals were the de-esterified acids of the parent compounds. This knowledge allowed us to predict that the crystalline precipitates would not be a hazard to humans because of the large multiples of the human dosage at which they occurred and because of differences in renal physiology between rats, dogs, and humans. (+info)
Measurement of cadmium-induced metallothionein in urine by ELISA and prevention of overestimation due to polymerization.
(53/7998)
Urinary metallothionein (MT) is a biological marker of cadmium (Cd) exposure and Cd-induced renal dysfunction. The MT is prone to oxidation due to high cysteine content and forms polymers, which can result in overestimation of the protein by immunochemical methods. The objectives of the present study were to develop an enzyme-linked immunosorbent assay (ELISA) for the measurement of MT in urine and to find ways by which the protein could either be preserved in its monomeric form or converted to this form before analysis to avoid overestimation. Urine specimens analyzed were either from rats repeatedly injected with Cd or from individuals chronically exposed to cadmium through their diets. The MT in rat urine remained in the monomeric form if the urine was collected at 4 degrees C but did not if it was collected at room temperature. The MT was also polymerized if the urine was subjected to repeated freezing and thawing. Overestimation of MT in rat urine occurred (as much as 12-fold) if the MT was polymerized. Addition of 5mM mercaptoethanol to freshly collected rat urine retarded MT polymerization, and addition of 50mM mercaptoethanol converted the polymerized MT to its monomeric form. Analysis of MT in frozen human urine samples revealed that if the urines were not treated with mercaptoethanol, the estimates of MT concentration were up to 11-fold higher than in the treated samples. We conclude that the polymerization of MT in rat and human urines is a serious problem and results in overestimation of the protein by ELISA and that this problem could be overcome by the addition of mercaptoethanol to the urine samples prior to analysis. (+info)
Clinicopathological study of renal involvement in patients with systemic sclerosis.
(54/7998)
OBJECTIVE: To assess the incidence of renal involvement in patients with systemic sclerosis (SSc) as well as its clinical and pathological changes. METHODS: The renal involvement was studied clinicopathologically in 93 patients who were compatible with the diagnosis of SSc retrospectively. RESULTS: Eighteen patients (19.4%) were diagnosed as renal involvement by one or more of the following: proteinuria, renal hypertension, elevated levels of blood urea nitrogen (BUN) and/or serum creatinine (sCr). Renal impairment was observed in 5 patients (5.4%). The mortality rate was 12.9%, and 5 patients died of renal failure. Histological study was performed in 5 patients. The thickening of interlobular arterioles with intimal proliferation was found in 4 of the patients who also showed mild nonspecific glomerular changes. Two had no clinical features of renal involvement, 1 had renal hypertension and 1 died of renal failure. Another patient with a 22-year disease duration showed chronic glomerulonephritis with nephrosclerosis. CONCLUSIONS: SSc patients should be followed-up clinically and renal biopsy performed if necessary in order to discover early renal involvement and to insert rational therapy to improve its prognosis. (+info)
Paracellin-1, a renal tight junction protein required for paracellular Mg2+ resorption.
(55/7998)
Epithelia permit selective and regulated flux from apical to basolateral surfaces by transcellular passage through cells or paracellular flux between cells. Tight junctions constitute the barrier to paracellular conductance; however, little is known about the specific molecules that mediate paracellular permeabilities. Renal magnesium ion (Mg2+) resorption occurs predominantly through a paracellular conductance in the thick ascending limb of Henle (TAL). Here, positional cloning has identified a human gene, paracellin-1 (PCLN-1), mutations in which cause renal Mg2+ wasting. PCLN-1 is located in tight junctions of the TAL and is related to the claudin family of tight junction proteins. These findings provide insight into Mg2+ homeostasis, demonstrate the role of a tight junction protein in human disease, and identify an essential component of a selective paracellular conductance. (+info)
Renal involvement in Gambian children with cerebral or mild malaria.
(56/7998)
Kidney function was studied in 80 Gambian children with cerebral malaria, 73 children with mild malaria, and in 19 children with other febrile illnesses. Serum creatinine was measured, and the excretion in urine of immunoglobulin G, transferrin, albumin and alpha 1 microglobulin was determined. Twenty-five percent of children with cerebral malaria, and 4% of children with mild malaria had an elevated serum creatinine above 62 mumol/l. Increased urinary protein excretion was frequent: 53% of children with cerebral malaria had a glomerulo-tubular pattern of protein excretion, and 46% a tubular pattern. Median albuminuria was 68 mg/l in children with cerebral malaria, 18 mg/l in children with mild malaria, and 9 mg/l in febrile children with other diseases (P < 0.0001). There was no significant association between the proteinuria and height of fever or the degree of parasitaemia, and there was no significant association between death and signs of renal impairment. Renal involvement is common in children with malaria in The Gambia, with prerenal, glomerular, and tubulo-interstitial factors contributing. It is more pronounced in children with cerebral malaria than in those with mild malaria. However, renal dysfunction is relatively mild and does not indicate a worse prognosis. (+info)