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Biomedical subjects

Wu-Chang Yang

Publications and source records attributed to Wu-Chang Yang.

17 recordsLinked to original sources

Acute interstitial nephritis and pigmented tubulopathy in a patient after wasp stings.

Acute renal failure (ARF) is an unusual complication of wasp stings and mostly results from toxic-ischemic acute tubular necrosis. This patient, who was stung by a swarm of wasps, experienced an allergic reaction, rhabdomyolysis, intravascular hemolysis, and subsequent ARF. The originality of this case report is related to the finding of combined lesions of acute tubulointerstitial nephritis and acute tubular nephropathy. From our extensive literature review, it is the first case of a patient developing this type of injury after wasp stings, and the complications have been documented previously only in one form or another. Renal biopsy should be encouraged, especially for a patient with delayed recovery of renal function after wasp stings, to facilitate early steroid treatment for the patient with the histological change of acute interstitial nephritis. Early use of steroid therapy may hasten renal recovery by preventing the development of interstitial fibrosis.

Acute Kidney Injury↗

Volume status and blood pressure during long-term hemodialysis: role of ventricular stiffness.

The importance of volume status on blood pressure in hemodialysis patients has long been recognized. We hypothesized that the enhanced volume dependency of blood pressure is partly determined by ventricular stiffness at end systole. A total of 115 long-term hemodialysis patients were invited to receive a comprehensive, noninvasive cardiovascular examination. End-systolic elastance was determined by using a novel, noninvasive echo-Doppler technique. The positive ratios of the interdialytic systolic blood pressure change vs weight gain during the subsequent 25 hemodialysis sessions were averaged to obtain the volume sensitivity index (mm Hg/kg). The averaged interdialytic weight gain per fat-free mass was correlated significantly with averaged percent change in systolic blood pressure (r=0.45, P<0.001). The estimated end-systolic elastance at baseline was significantly correlated with subsequently observed volume sensitivity index (volume sensitivity index=[1.17xend-systolic elastance]+6.4; r=0.34, P=0.001). End-systolic elastance was also significantly correlated with various vascular function parameters, including effective arterial elastance (r=0.48, P<0.001), pulse wave velocity (r=0.30, P=0.001), carotid augmentation index (r=0.31, P<0.001), and aortic compliance (r=-0.49, P<0.001). The results suggest that end-systolic elastance, a direct measure of left ventricular mechanical properties at end systole, is coupled to arterial mechanical properties and predicts the extent of subsequent interdialytic systolic blood pressure rise relative to weight gain. Therefore, ventricular stiffness at end systole is a determinant of the enhanced volume sensitivity of blood pressure in hemodialysis patients.

Adult↗

The extracellular fluid-to-intracellular fluid volume ratio is associated with large-artery structure and function in hemodialysis patients.

BACKGROUND: Large-artery derangement is a major risk factor for cardiovascular and all-cause mortality in patients with end-stage renal disease (ESRD). It is not clear how body fluid distribution affects large-artery structure and function in patients with ESRD. METHODS: One hundred fifty-seven hemodialysis (HD) patients (mean age, 55.9 +/- 15.1 years; 76 men, 81 women) were enrolled. Influence of the extracellular fluid (ECF)-to-intracellular fluid (ICF) ratio derived from bioimpedance spectroscopy on the structure and function of the common carotid artery (CCA) and aorta was analyzed. One hundred forty-four healthy subjects were examined to obtain normal reference values for body fluid compartments. Based on ECF-ICF ratio, 2 groups were identified: ECF-ICF ratio in the 95th percentile or less and ECF-ICF ratio greater than the 95th percentile of age- and sex-stratified normal reference values. RESULTS: ECF-ICF ratio was significantly related to CCA diameter (r2 = 0.26; P < 0.001), CCA incremental modulus (E(inc); r2 = 0.15; P < 0.001), carotid augmentation index (AGI; r2 = 0.10; P < 0.001), and aortic pulse wave velocity (aPWV; r2 = 0.21; P < 0.001). ECF-ICF ratio remained a significant independent determinant for CCA diameter (model r2 = 0.47; P < 0.001), E(inc) (r2 = 0.29; P < 0.001), aPWV (r2 = 0.51; P < 0.001), and AGI (r2 = 0.40; P < 0.001) when age, sex, mean blood pressure, anthropometrical parameters, HD duration, and status of diabetes mellitus were accounted for. HD patients with an ECF-ICF ratio greater than the 95th percentile had a greater CCA diameter, E(inc), aPWV, and AGI than their counterparts. CONCLUSION: ECF-ICF ratio is associated with large-artery structure and function in HD patients. Patients with ESRD with a high ECF-ICF ratio are characterized by significant large-artery derangement.

Adult↗

Primary Sjögren's syndrome associated with Gitelman's syndrome presenting with muscular paralysis.

A 38-year-old woman presented with muscle cramping of 4 extremities and paralysis for months. Laboratory results showed an elevated antinuclear antibody titer; antibodies to the ribonucleoprotein antigen Ro; hypokalemia; hypomagnesemia with hyperreninemia, but abnormally high urine potassium and magnesium levels and low urine calcium levels; and a blunted diuretic effect to thiazide, but not furosemide, which met the criteria for Gitelman's syndrome (GS) and led to the diagnosis of primary Sjögren's syndrome (pSS). She received medical treatment, including a potassium supplement and aldosterone antagonist. GS as a presentation of pSS has never been reported in the literature. The features of renal diseases related to SS are reviewed. SS is the underlying cause of GS, which may precede the onset of the well-known sicca complex.

Adult↗

Lipoprotein glomerulopathy associated with psoriasis vulgaris: report of 2 cases with apolipoprotein E3/3.

Lipoprotein glomerulopathy (LPG) is a rare disease, characterized by a special histology, including dilated glomerular capillaries filled with pale-stained and meshlike lipoprotein thrombi. It always presents with proteinuria or nephrotic syndrome. Although hyperlipidemia is not always seen, most patients have type III hyperlipoproteinemia with apolipoprotein (apo) E2/3 phenotyping. Although the clinical feature of LPG is rarely described, LPG associated with other glomerulopathy, including IgA nephropathy, membranous nephropathy, and lupus nephritis, has been documented. Until now, there have been no reports of psoriasis vulgaris associated with LPG. The authors present 2 cases of LPG with apo E3/3 genotyping associated with psoriasis vulgaris. The first patient was a 65-year-old woman who presented with nephrotic syndrome with daily urinary protein loss of 9.05 g and itchy erythematous scaly plaques on her trunk and lower limbs for 1 year. The renal biopsy results showed LPG, and the skin biopsy results showed psoriasis. The second patient was a 50-year-old man with history of psoriasis over his trunk and 4 limbs for 30 years. He also presented with nephrotic syndrome with daily urinary protein loss of 7.55 g. The renal biopsy results also showed LPG. The genotype of apo E showed E3/3, and lipoprotein electrophoresis showed a type III hyperlipoproteinemia-like pattern in both cases. The authors suggest that presence of apo E3/3 genotype cannot rule out the diagnosis of type III hyperlipoproteinemia and LPG. Besides, LPG should be included in the differential diagnosis of psoriatic patients with nephrotic syndrome, especially in Asian patients who show poor response to traditional therapy. Renal biopsy should be performed to make the definitive diagnosis.

Aged↗

Antineutrophil cytoplasmic antibody-negative pauci-immune crescentic glomerulonephritis associated with rheumatoid arthritis: An unusual case report.

Clinically relevant renal lesions in rheumatoid arthritis (RA) are not common. More often renal involvement is related to complications of therapy than the disease itself. The most common forms of primary renal disease in RA are membranous glomerulonephropathy and a pure mesangial proliferative glomerulonephritis. Some studies have described the association between crescentic glomerulonephritis (crescentic GN) and RA, but they were all found to be perinuclear antineutrophil cytoplasmic antibody (p-ANCA) positive. However, RA associated with ANCA negative pauci-immue crescentic GN has not been reported. This is a case report of a 37-year-old female with RA who initially presented with general oedema and acute deterioration of renal function. The renal biopsy revealed ANCA negative pauci-immune crescentic GN. The patient was treated with steroid pulse and plasmapheresis, but not cyclophosphamide because of severe urosepsis. Despite the use of aggressive therapy, her renal function was not improved and she underwent maintenance haemodialysis thereafter. Because ANCA negative crescentic GN may occur in RA patients without frank systemic vasculitis, but with severe clinical manifestation, a heightened suspicion for a relatively 'silent' crescentic GN would have led to the correct diagnosis and appropriate treatment.

Acute Kidney Injury↗

TNF-alpha renders human peritoneal mesothelial cells sensitive to anti-Fas antibody-induced apoptosis.

BACKGROUND: Fas-mediated apoptosis is important in the regulation of immune response. Human peritoneal mesothelial cells (HPMCs) are able to regulate peritoneal inflammation, but the role of Fas in HPMCs is not clear. This study addresses the mechanisms of Fas-mediated apoptosis in HPMCs. METHODS: Tumour necrosis factor-alpha (TNF-alpha) primed HPMCs were stimulated with agonistic anti-Fas antibody. The expression of Fas was evaluated by real-time reverse transcription polymerase chain reaction (TaqMan quantitative polymerase chain reaction) and flow cytometry. Apoptosis was assessed by nuclear morphology, TUNEL assay, fractional DNA content and cytokeratin 18 cleavage. Caspase activation and bcl-2 expression were analysed by western blotting. The phagocytosis of apoptotic HPMCs was demonstrated by immunofluorescence and transmission electron microscopy. RESULTS: Cultured HPMCs constitutively expressed Fas, and the Fas expression was upregulated by TNF-alpha. TNF-alpha primed HPMCs underwent apoptosis after anti-Fas antibody treatment, and the apoptotic HPMCs could be phagocytosed by macrophages. TNF-alpha was able to downregulate bcl-2 expression. Activation of caspase-3 and caspase-8 was noted during the apoptotic process. The inhibitors of either caspase-3 or caspase-8 could prevent the Fas-induced apoptosis in HPMCs. We also detected increased HPMC apoptosis in dialysate effluent during the recovery phase of peritonitis in peritoneal dialysis patients. CONCLUSIONS: TNF-alpha directs HPMCs to commit apoptosis via the Fas/Fas ligand pathway through a modulation of Fas and bcl-2. Our study shows that HPMCs undergo apoptosis during peritonitis and suggests that the apoptosis of HPMCs may be related to the resolution of peritoneal inflammation.

Apoptosis↗

Left ventricular mass and hemodynamic overload in normotensive hemodialysis patients.

BACKGROUND: It remains uncertain whether the hemodynamic parameters are important determinants of left ventricular mass (LVM) in normotensive chronic hemodialysis (NTHD) patients, as has been found in their hypertensive counterparts. METHODS: Forty NTHD patients (mean age, 53.7 +/- 14.4 years; male/female, 18/22) without the requirement of antihypertensive drugs for at least six months were studied. Controls were 41 hypertensive hemodialysis patients (HTHD) and 46 normotensive subjects with normal renal function (NTNR). The influence of anthropometrics, cardiovascular structure and function, and volume status on LVM (by two-dimensional echocardiography) was analyzed by steps of multiple linear regression. RESULTS: As compared with the NTNR and NTHD group, the HTHD group had obvious pressure and volume/flow overload, and greater LV wall thickness, chamber size and mass. In contrast, NTHD subjects had similar blood pressure, large artery function, LV chamber size and stroke volume as the NTNR subjects. However, the NTHD patients still had greater wall thickness and LVM, along with greater cardiac output, lower total peripheral resistance and lower end-systolic meridional stress to volume ratio (ESSV) than the NTNR group. LVM in the NTHD group was significantly positively related to averaged systolic blood pressure (SBPavg), body surface area, extracellular fluid (ECF), carotid intima-media thickness (IMT), aortic pulse wave velocity (PWV), and negatively related to ESSV and Kt/V. The independent significant noncardiac structural determinants of LVM in NTHD subjects were ESSV, SBPavg, PWV and SV (model r2 = 0.617, P < 0.001). CONCLUSIONS: The NTHD patients, without significant pressure and volume overload, still had increased LVM that was partially explained by the persistent flow overload and subclinical LV dysfunction.

Adult↗

Hypercalcemia in a renal transplant recipient suffering with Pneumocystis carinii pneumonia.

Hypercalcemia occurs frequently after renal transplantation. Preexisting hyperparathyroidism is the most common cause of post-transplantation hypercalcemia. We describe a renal transplant recipient infected with Pneumocystis carinii pneumonia (PCP) who developed hypercalcemia, elevated 1,25-dihydroxyvitamin D, and suppressed parathyroid hormone levels. This phenomenon mimics the extrarenal production of 1,25-dihydroxyvitamin D by activated alveolar macrophages in granulomatous diseases with hypercalcemia. To the best of our knowledge, this is the first report of 1,25-dihydroxyvitamin D-mediated hypercalcemia caused by PCP in a renal transplant recipient. This entity should be included in the differential diagnosis for renal transplant recipients with hypercalcemia, especially in patients who develop lung infections.

Diagnosis, Differential↗

An open-label, crossover study of a new phosphate-binding agent in haemodialysis patients: ferric citrate.

BACKGROUND: Hyperphosphataemia contributes to secondary hyperparathyroidism and renal osteodystrophy in patients with end-stage renal disease (ESRD). Calcium salts are widely employed to bind dietary phosphate (P) but they may promote positive net calcium balance and metastatic calcification. We recently reported that ferric compounds bind intestinal phosphate in studies of normal and azotemic rats. METHODS: To extend this observation, we performed an open-label, random order, crossover comparison study of ferric citrate and calcium carbonate in haemodialysis patients from two teaching hospitals. The study sample consisted of 23 women and 22 men with an average age of 52.5 +/- 11.8 (SD) years and an average weight of 54.5 +/- 10.7 kg. All forms of iron therapy were discontinued. Two weeks before the study, patients were instructed to discontinue all P-binding agents. The patients were randomly assigned to receive either calcium carbonate (3 g/day) or ferric citrate (3 g/day) for 4 weeks followed by a 2 week washout period, and then crossed over to the other P-binding agent for 4 weeks. RESULTS: From a baseline concentration of 5.6 +/- 1.5 mg/dl, the serum P increased during the washout period to 7.2 +/- 1.9 mg/dl prior to calcium carbonate treatment, and to 6.7 +/- 1.9 mg/dl prior to ferric citrate treatment. The serum P concentration fell significantly during treatment with both calcium carbonate (7.2 +/- 1.9 to 5.2 +/- 1.5 mg/dl, P<0.0001) and ferric citrate (6.7 +/- 1.9 to 5.7 +/- 1.6 mg/dl, P<0.0001). The results were not influenced by order of treatment. Under the conditions of the study protocol, ferric citrate was less effective than calcium carbonate at lowering the serum phosphate concentration. The serum Ca concentration increased during treatment with calcium carbonate but not ferric citrate. Ferric citrate treatment did not affect the serum concentration of aluminium. Ferric citrate treatment was associated with mild and generally tolerable gastrointestinal symptoms. CONCLUSION: Ferric citrate shows promise as a means of lowering the serum phosphate concentration in haemodialysis patients. Further studies are needed to find the optimal dose.

Adult↗

IgA deficiency with membranous glomerulonephritis: a case report and review.

Selective immunoglobulin A (IgA) deficiency may result in a predisposition to recurrent sinopulmonary infection and allergic diseases. IgA deficiency may also play a role in the development of autoimmune disorders. Selective IgA deficiency associated with glomerulonephritis was rare, while the clinical presentation in IgA deficiency-associated glomerulonephritis was variable. We report an 83 year-old male with selective IgA deficiency associated with membranous glomerulonephritis. He presented with nephrotic syndrome. Percutaneous renal needle biopsy showed diffuse global thickening and rigidity of glomerular capillary walls, mildly diffuse segmental expansion of mesangial matrix, focal and cortical scar with segmental obsolescence of glomeruli. Heavy IgG and moderate C3 deposits were found on immunofluorescence. We also review the previous cases of IgA deficiency with glomerulonephritis. Several clues were rendered to establish the association between IgA deficiency and membranous glomerulonephritis.

Aged↗

Tacrolimus-associated hemolytic uremic syndrome: a case analysis.

BACKGROUND: Tacrolimus is an effective organ transplantation immunosuppressant. Hemolytic uremic syndrome (HUS) is a rare but severe complication of tacrolimus. METHODS: We report a case of tacrolimus-associated HUS and review the 15 previously reported cases. RESULTS: The results of the 16 cases indicated that tacrolimus-associated HUS is more frequent in females (56.3%), with the mean age at onset of 41.3 years. Forty-four percent of cases received renal transplantations. The average time from the first tacrolimus dose to HUS onset was 7.1 months. Prevalence was between 0.14.7%. The tacrolimus trough level did not predict the prognosis. Seven patients (43.7%) had improved graft function after treatment, including anticoagulation and antiplatelet therapy, reduction or discontinuation of tacrolimus, switch to cyclosporine (CyA), plasma exchange (PE) and dialysis. Five patients (31.3%) died and four patients (25%) lost their graft in spite of the above treatment. Mortality risk factors for transplant recipients with tacrolimus-associated HUS included: (1) non-renal transplant recipients (100% vs. 36.4%, p = 0.034); (2) lower peak serum Cr (2.58 +/- 1.23 vs. 6.16 +/- 1.96, p < 0.002); (3) liver dysfunction (60% vs. 0, p < 0.02); (4) higher serum lactate dehydrogenase (LDH) level (3119 +/- 1019 vs. 982 +/- 522, p < 0.001). A lower platelet count carried borderline mortality risk (29500 +/- 14480 vs. 59625 +/- 25584, p = 0.057). CONCLUSIONS: HUS should be included in the differential diagnosis of renal function deterioration in patients on tacrolimus post-organ transplantation. Frequent renal function monitoring and appropriate treatment should be performed aggressively to decrease morbidity and mortality, especially in patients with risk factors.

Adult↗