Search PubMed⌕ Search

Biomedical subjects

K Lhotta

Publications and source records attributed to K Lhotta.

At least 19 recordsLinked to original sources
PubMed1998

Management of hyperparathyroidism in an endemic goiter area.

In an endemic goiter area patients with hyperparathyroidism (HPTH) frequently also have thyroid abnormalities. In a retrospective study of 95 patients with HPTH we assessed the diagnostic accuracy of imaging techniques (ultrasonography or radionuclide scanning) for preoperative localization of parathyroid adenomas. Altogether 86% of our patients had goiter, requiring thyroid resections in 37%. For 19 patients the parathyroid exploration was the second or third cervical operation, most of them due to goiter. We found that the overall rate of transient and permanent recurrent nerve paralysis is considerably increased in patients with previous neck surgery (26% vs. 7%). The combination of ultrasonography and radionuclide scanning can lead surgeons to the site of parathyroid lesions responsible for HPTH in 85% of cases, although frequent nodular goiters can produce pitfalls for correct imaging in iodine-deficient countries. In endemic goiter areas preoperative localization studies can be recommended in patients with primary HPTH--for evaluation of thyroid pathology possibly leading to resection or its accuracy in localizing parathyroid adenomas. These studies also seem justified in patients with previously unsuccessful neck explorations for HPTH.

Adolescent↗
PubMed1998

Reinforced intradermal hepatitis B vaccination in hemodialysis patients is superior in antibody response to intramuscular or subcutaneous vaccination.

Since 1960, hepatitis B virus-associated chronic liver disease has been considered an important problem in dialysis units in both Europe and North America. Separate dialysis facilities for hepatitis B-infected patients, the implementation of universal precautions for the prevention of transmission, and the active immunization against hepatitis B have now reduced the yearly incidence to less than 0.05% in Western countries. However, only 50% to 60% of patients with renal insufficiency develop sufficient immune response after intramuscular hepatitis B vaccination. The aim of the current study was to determine whether the mode of vaccine application plays a role in vaccination response and whether increasing the vaccine dose of primary intradermal hepatitis B vaccination can reduce the number of vaccine injections in hemodialysis patients. We designed a prospective, randomized study of antibody responses to hepatitis B vaccine given intradermally, subcutaneously, or intramuscularly in 81 hemodialysis patients. Outcome measures were rates of seroconversion, mean levels of anti-Hbs antibodies, and antibody levels 8 years after vaccination. The results show that intradermal hepatitis B vaccination response with a higher vaccination dose than previously used in hemodialysis patients is superior to conventional intramuscular and subcutaneous vaccination and is also well tolerated. Five intradermal injections of 20 microg each induced the development of sufficient anti-Hbs antibody titer, which persisted in 70% of the patients over 3 years.

Adult↗
PubMed1998

Rapid activation of the complement system by cuprophane depends on complement component C4.

Hemodialysis with cuprophane dialyzer membranes promotes rapid activation of the complement system, which is thought to be mediated by the alternative pathway. Complete hereditary deficiency of complement C4, a classical pathway component, in two hemodialysis patients provided the opportunity to investigate a possible role of the classical pathway. In two hemodialysis patients with both C4 isotypes, C4A and C4B, and in one patient with C4B deficiency complement activation occurred immediately after the onset of hemodialysis, with peak levels of C3a and terminal complement complex (TCC) after ten to fifteen minutes. In patients with complete C4 deficiency, C3a and TCC remained unchanged for fifteen minutes and increased thereafter, reaching the highest level after thirty minutes. The leukocyte nadir was also delayed from fifteen to thirty minutes. In vitro incubation of normal, C4A- or C4B-deficient serum with cuprophane caused complement activation after fifteen minutes. In contrast, no activation was observed in sera of four C4-deficient patients. The addition of normal serum or purified human C4 restored the capacity for rapid complement activation. In one patient with severe immunoglobulin deficiency, C3a and TCC levels increased only moderately after 25 minutes of cuprophane dialysis. This patient's serum also exhibited delayed complement activation in vitro, which was normalized after pretreatment of cuprophane with immunoglobulins. Preincubation of normal serum with MgEGTA, a blocker of the classical pathway, inhibited rapid complement activation through cuprophane. As basal levels of C4a are markedly increased in hemodialysis patients (3450 +/- 850 ng/ml) compared to healthy controls (224 +/- 81 ng/ml), no further elevation of C4a was detectable during cuprophane hemodialysis. Incubation of normal serum with cuprophane, however, caused a slight increase in C4a after five minutes. These results indicate that the initial deposition of complement C3b on the cuprophane membrane, necessary for activation of the amplification loop of the alternative pathway, is mediated by the classical pathway C3-convertase C4b2a. We propose an extended concept of complement activation through cuprophane, which is based on four steps: (a) binding of anti-polysaccharide antibodies, (b) classical pathway activation, (c) alternative pathway activation and (d) terminal pathway activation.

Adolescent↗
PubMed1998

Adrenocortical carcinoma evolving after diagnosis of preclinical Cushing's syndrome in an adrenal incidentaloma. A case report.

A 43-year-old female patient underwent abdominal ultrasonography and CT scan because of uncharacteristic abdominal pain. A 3-cm homogeneous adrenal tumor was diagnosed. The endocrine tests revealed an adrenal preclinical Cushing's syndrome (PCS). Due to the latent hormone excess we decided to operate on the adrenal tumor. Since the tumor was small, laparoscopic adrenalectomy was performed. Histological evaluation showed an adrenocortical tumor of undetermined nature. Four months later the patient presented with a metastasizing cortisol- and androgen-producing adrenocortical carcinoma (ACC). After pretreatment with ketoconazole to suppress the biosynthesis of adrenal steroids under substitution with hydrocortisone, we reduced the tumor load by surgery. Postoperatively we continued ketoconazole and started o, p'-dichlorodiphenyldichloroethane as well as chemotherapy with doxorubicin and suramin. However, the patient died from ACC 7 months after adrenalectomy. It is known from several reports that PCS may persist clinically silently or may progress to full-blown Cushing's syndrome. This is the first time a malignant course of PCS is described. Independent of the initial therapeutic strategy of PCS, i. e. surgery or regular follow-up visits, we must be aware that also relatively small adrenal tumors can harbor malignancy.

Adrenal Cortex Neoplasms↗
PubMed1998

Apoptosis of tubular epithelial cells in familial juvenile gouty nephropathy.

Two patients, a 47-year-old woman suffering from chronic renal failure, hyperuricemia and gout, and her 26-year-old son with hyperuricemia and chronic renal failure, are described. The father and two siblings of the woman had died of chronic renal failure. Both patients had a markedly reduced fractional excretion of urate, which was significantly increased by both benzbromarone and probenecid. A renal biopsy of the son revealed an unspecific chronic tubulointerstitial nephropathy. By light microscopy, many proximal tubular epithelial cells showed signs of apoptosis, which was confirmed with the specific TUNEL assay. We propose a hypothesis based on a gain-of-function mutation of the luminal anion exchanger of the proximal tubulus to explain reduced uric acid excretion, dominant inheritance and apoptosis of tubular epithelial cells in this rare disease. Treatment with a combination of allopurinol to reduce the renal urate load and benzbromarone to block the tubular anion exchanger and normalize fractional uric acid excretion is suggested.

Adult↗
PubMed1997

Adrenal-sparing laparoscopic surgery for aldosterone-producing adenoma.

We herein present the first case in the literature of enucleation of an aldosterone-producing adenoma by laparoscopy. The indication for adrenal-sparing surgery was bilateral adrenal adenoma. The operation turned out to be easier than laparoscopic adrenalectomy. The postoperative course was uneventful, and the patient was cured; split adrenal function tests showed normal function of both adrenal glands.

Adenoma↗
PubMed1997

Soluble intercellular adhesion molecule-1 (ICAM-1) in serum and urine: correlation with renal expression of ICAM-1 in patients with kidney disease.

A soluble form of intercellular adhesion molecule-1 (sICAM-1) has been described in serum and other body fluids. In order to determine whether sICAM-1 in serum and urine is a useful marker of inflammatory activity in kidney diseases we measured sICAM-1 in serum and urine of fifty patients who underwent renal biopsy, and of twenty healthy individuals. Expression of ICAM-1 on proximal tubular epithelial cells was investigated by immunohistochemistry. Soluble ICAM-1 in serum did not differ between patients and controls (354 +/- 129 ng/ml vs. 305 +/- 52 ng/ml). By multiple regression analysis sICAM-1 correlated with tubular expression of ICAM-1 (p < 0.01), but not with serum creatinine, infiltrating leukocytes, urinary ICAM-1 or proteinuria. In healthy controls mean urinary ICAM-1/cr was 2.5 +/- 3.0 ng/mg creatinine and differed significantly from that of patients (14.5 +/- 14.9 ng/mg) (p < 0.005). Patients with minimal-change disease had the highest uICAM-1 levels. The ratio of urinary ICAM-1 and proteinuria was remarkably constant in all patients with 6.0 +/- 0.9 ng/mg. By multiple regression analysis uICAM-1/cr correlated with proteinuria/cr (p < 0.001) and sICAM-1 (p < 0.005). These data show that sICAM-1 does to some degree reflect ICAM-1 expression in the kidney, whereas uICAM-1 is derived from glomerular filtration and closely parallels proteinuria. Both sICAM-1 and uICAM-1 are not useful to estimate ICAM-1 expression and inflammatory activity in the kidney.

Biomarkers↗
PubMed1997

Renovascular arteriovenous differences in Lp[a] plasma concentrations suggest removal of Lp[a] from the renal circulation.

High plasma concentrations of lipoprotein[a] (Lp[a]) are considered a genetically determined risk factor for atherosclerosis. Lp[a] is produced by the liver. The site(s) and mechanism(s) of catabolism are presently unclear. Lp[a] is elevated secondary to end-stage renal disease which suggests a direct or indirect role of the kidney in the metabolism of Lp[a]. We therefore investigated, by a simple in vivo approach, whether Lp[a] is removed by the human kidney. Lp[a] plasma concentrations were measured simultaneously by various methods in the ascending aorta and renal vein of 100 patients undergoing coronary angiography or coronary angioplasty. Lp[a] levels differed significantly between the two vessels even after correcting for hemoconcentration (20.1 +/- 21.6 mg/dL versus 18.7 +/- 20.3 mg/dL, P < 0.001). This corresponds to a mean arteriovenous difference of -1.4 mg/ dL or -9% of the arterial concentration. No Lp[a] or intact apo[a] could be detected in urine from healthy probands. Although we cannot assign the kidney a regulatory role for Lp[a] plasma levels in humans with normal renal function, we conclude from our data that substantial amounts of this atherogenic lipoprotein are taken up by the kidney. The underlying mechanisms are unknown at the moment. This study therefore demonstrates for the first time that the human kidney plays an active role in the catabolism of Lp[a]. This may explain the elevated Lp[a] concentrations found in patients with chronic renal insufficiency.

Aged↗
PubMed1996

Recurrent hematuria: a novel clinical presentation of hereditary complete complement C4 deficiency.

A 10-year-old boy suffered from recurrent attacks of fever, vomiting, and hematuria. During disease flares, circulating immune complexes were detected in the serum. Elevated levels of Bb, Ba, and C3a indicated complement activation through the alternative pathway. Complement C4 was undetectable. C4 phenotyping by agarose gel electrophoresis showed complete C4 deficiency. Restriction fragment length polymorphism (RFLP) studies showed a homozygous deletion of the C4B and 21-hydroxylase A genes. A mild mesangioproliferative glomerulonephritis with mesangial deposits of immunoglobulin (1g) G, IgM, IgA, Clq, C3, properdin, and terminal complement complex was probably caused by immune complex deposition and alternative complement pathway activation. Treatment with low-dose prednisolone substantially reduced the frequency of further episodes.

Biopsy↗
PubMed1996

Complement C4 phenotypes in patients with end-stage renal disease.

The phenotypes of complement C4 were determined by agarose gel electrophoresis in 130 patients with end-stage renal failure of various causes and compared with those of 140 healthy controls. C4 allotype frequencies did not differ between patients and controls. Null alleles of both isotypes C4A and C4B were increased, but also without reaching significance. In type 1 diabetics an increased frequency of C4AQ0 (25 vs. 11.8%, p < 0.05) was found. Patients with two null alleles were far more frequent in the group with insulin-dependent diabetes mellitus (25 vs. 3.6%, p < 0.01). We confirmed the presence of a previously described uremic variant of C4B1. Additional uremic variants of C4 were detected in uremic patients homozygous for C4A3, B2 and B3. The relative electrophoretic migration values of the uremic variants of C4A3, B1, B2 and B3 were 132.1 +/- 2.9, 35.8 +/- 1.5, 70.4 and 73.9. These variants appear early in the course of chronic renal failure and disappear after successful renal transplantation. Uremic variants are the only acquired C4 phenotypes known so far. How uremia causes these variants remains unclear, but probably involves carbamylation of the C4 molecule.

Alleles↗
PubMed1996

Polymorphism of complement C4 and susceptibility to IDDM and microvascular complications.

OBJECTIVE: The aim of this study was to investigate whether or not the inherited polymorphism of complement C4 is associated with genetic susceptibility to microvascular complications in IDDM as previously reported. RESEARCH DESIGN AND METHODS: We determined C4 phenotypes in 241 patients with IDDM and 140 healthy control subjects by agarose gel electrophoresis and immunoprecipitation. C4 allotype frequencies were compared between patients and healthy control subjects. In addition, we compared allotype frequencies of 83 patients with nephropathy with those of 80 patients without nephropathy and compared those of 50 patients with proliferative retinopathy with those of 68 patients without retinopathy or background retinopathy. Duration of IDDM in control patients was at least 21 years. RESULTS: Patients and healthy control subjects differed at both the C4A (P < 0.00001) and C4B (P < 0.0005) loci. The C4 null allele C4AQ0 was significantly increased in IDDM patients (26.8 vs. 11.8%, P < 0.005). C4B2 was more frequently observed in patients (14.5 vs. 6.8%, P < 0.05) compared with healthy control subjects. No differences were observed in C4 allotype distribution between patients with and without nephropathy or retinopathy. CONCLUSIONS: These data confirm previous reports of an association between the C4 null allele C4AQ0 and IDDM. Our results do not support an association of the inherited polymorphism of complement C4 with genetic susceptibility to microvascular complications in patients with IDDM.

Adolescent↗
PubMed1996

Glomerular deposition of the complement C4 isotypes C4A and C4B in glomeruonephritis.

BACKGROUND: Complement C4 is a component of the classical complement pathway, which is a major mediator of inflammation in many forms of glomerulonephritis. The two isoforms of C4-C4A and C4B-differ in their physicochemical and functional properties. METHODS: The glomerular deposition of C4A and C4B was investigated in 39 cases of glomerulonephritis with classical pathway activation using isotype-specific monoclonal antibodies 99H7 (C4A) and 1288 (C4B) and indirect immunofluorescence. Complement C4 phenotypes of all patients were determined by agarose gel electrophoresis and immunoprecipitation. RESULTS: Three biopsies contained only the isotype C4B. C4 phenotyping revealed complete C4A deficiency in these three patients. Both isotypes C4A and C4B were detected in 36 biopsies. In 19 (53%) thereof staining for both isotypes was identical. In the remaining 17 (47%), staining intensity of C4A predominated over C4B. The distribution of these two staining patterns did not differ between membranous glomerulonephritis and lupus nephritis. They were also independent of C4A and C4B allotypes including the presence or absence of null alleles at either gene locus. In no case was C4B staining stronger than C4A staining. Serum creatinine and proteinuria did not differ between patients with identical and C4A-dominant C4 deposition. CONCLUSIONS: The most likely but still hypothetical explanation for predominance in glomerular deposition of C4A over C4B in many cases of immune complex-mediated glomerulonephritis is the greater affinity of C4A to protein-containing immune complexes as compared to C4B.

Adolescent↗
PubMed1996

Acute renal failure complicating non-fulminant hepatitis A.

Hepatitis, A is usually a mild and self-limiting infection of the liver. Whereas the clinical course is usually benign in children, complications such as prolonged cholestasis and fulminant liver failure have been reported in adults. Acute functional renal failure is an uncommon event in the absence of fulminating liver disease. So far, only cases of acute hepatitis A with biopsy-proven interstitial renal disease or tubular necrosis have been reported [Geltner et al. 1992. Kramer et al. 1986]. We present the case of a 35-year-old, previously healthy male with non-fulminant cholestatic viral hepatitis A, who developed progressive oliguric renal failure requiring dialysis therapy. Kidney biopsy ruled out glomerular disease and tubular necrosis. In the absence of bleeding and other causes of fluid depletion this case may be another variant of hepatorenal syndrome whose etiopathogenesis is only poorly understood.

Acute Kidney Injury↗