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Our previous study showed that the mutation hotspots of the K-ras proto-oncogene in human functional adrenocortical tumors are in codons 15, 16, 18, and 31, thus differing from the sites in other tumors. In addition, analyzing the K-Ras protein by a recombinant DNA technique showed that the activity of endogenic GTPase and the GTPase-activating protein (GAP)-binding ability were significantly decreased in patients with these tumors. The aim of this study was to understand whether those K-ras mutants, which were found only in human adrenocortical tumors, play an important role in these tumors. Thus, the mutant K-ras cDNA was constructed with mammalian expression vectors and transfected into normal adrenocortical cells. The amount of cortisol secreted by the transfected cells was 20 to 30 times that of normal cells. Furthermore, Northern blot analysis revealed that the expression of the three steroidogenesis-related genes P450(scc) (cholesterol side-chain cleavage enzyme), P450(C17) (17alpha-hydroxylase/17, 20-lyase), and P450(C21) (steroid 21-hydroxylase) gene increased in the transfected cells. The K-ras oncogene significantly increases cortisol secretion by normal adrenocortical cells.

Insulin and heparin suppress superoxide production in diabetic rat glomeruli stimulated with low-density lipoprotein. Patients with diabetic nephropathy frequently show increased levels of circulating low-density lipoprotein (LDL) and oxidized LDL, which have been reported to be related to the generation of oxygen-free radicals. In the present study, we evaluated the effects of insulin and heparin on the superoxide production of glomeruli, which were isolated from rats with streptozotocin-induced diabetes for one week, one month, and three months, respectively, and the glomeruli were stimulated with native and oxidized LDL. LDL was isolated from normal subjects with normolipidemia, and the superoxide was measured by using a spectrophotometer. The results demonstrated that the poorly controlled diabetic rat glomeruli showed a significantly higher production of superoxide than normal glomeruli under basal status and after stimulation, and this production increased further with the progression of diabetes. Insulin suppressed both the basal and stimulated production of superoxide in diabetic glomeruli, but not in normal glomeruli. Heparin suppressed superoxide production of diabetic glomeruli stimulated by either native or oxidized LDL, and it also partly suppressed superoxide production of normal glomeruli stimulated by oxidized LDL. Our results suggest that glomerular injury in diabetics with hyperlipidemia may be mediated through enhanced generation of oxygen-free radicals, which can be partially attenuated by insulin and heparin.

Background/Aims: Hemodialysis (HD) patients are prone to developing peptic ulcers. However, of all the risk factors associated with peptic ulcers, none have been shown to be more prevalent in HD patients than in the general population. However, salivary epidermal growth factor (EGF) may play a role in peptic ulcer diseases. Methods: Salivary EGF levels and bioactivities were assayed in 47 maintenance HD patients and 30 normal controls, and the molecular weights of EGF were assessed using high-performance liquid chromatography (HPLC). Results: Salivary EGF levels were not different between both groups of subjects (4.2 ± 0.34 vs. 5 ± 0.54 ng/mg protein, NS), and HPLC revealed that salivary EGF in both groups had similar molecular weights. However, salivary EGF bioactivity was significantly depressed in the HD patients as compared to the normal controls (0.59 ± 0.08 vs. 1.55 ± 0.15 ng/mg protein, p < 0.01). Stepwise multiple regression showed that the low salivary EGF levels were associated with female gender (p < 0.05), while low salivary EGF bioactivity was associated with HD per se (p < 0.05). In the 22 HD patients who underwent gastric endoscopy, salivary EGF bioactivity was significantly lower in those with peptic ulcers than in those without (0.38 ± 0.08 vs. 0.69 ± 0.08 ng/mg protein, p < 0.05). Conclusion: Decreased salivary EGF bioactivity may contribute to peptic ulcer disease among maintenance HD patients.

To investigate the role of renal endothelin-1 (ET-1) synthesis in water-sodium homeostasis, we measured mRNA expressions, protein levels, enzyme activity, and receptor binding of the renal ET-1 system in a DOCA- and salt-treated rat model. Male Wistar rats were divided into control and DOCA- and salt-treated (DOCA-Salt) groups. The DOCA-Salt group received 25 mg/kg body wt DOCA and was maintained on 1% NaCl drinking water. Rats were killed on days 1, 2, 4, and 10 of the experiment. Urinary ET-1-like immunoreactivity significantly increased from the second day in the DOCA-Salt group and correlated well with the urinary sodium excretion rate ( r = 0.81, P < 0.001). Renal endothelin-converting enzyme (ECE) activity, ET-1, and ECE-1 mRNA expressions were significantly increased in the renal medullary area of DOCA-Salt rats. In situ hybridization and immunohistochemical studies showed that the increase in ET-1 synthesis was mainly localized in the inner medullary collecting ducts. The maximum binding of endothelin B receptor also increased from the second day in the renal medulla of the DOCA-Salt group. Our results suggest that renal medullary synthesized ET-1 may be a natriuretic factor and may participate in the intrarenal regulation of water and salt homeostasis in prehypertensive DOCA-and salt-treated rats.

Background. Diabetes is one of the major causes of end-stage renal failure in the Taiwanese population. Previous studies have shown that angiotensin-converting enzyme (ACE) inhibitor can improve glucose utilization and suppress hepatic glucose production and the renin-angiotensin system may play an important role in the initiation and progression of diabetic nephropathy. Thus, ACE gene polymorphism may be associated with type 2 diabetes and diabetic nephropathy. Methods. To investigate the distribution of ACE-I/D genotype in type 2 diabetes and diabetic nephropathy, we examined 336 patients with type 2 diabetes (157 without nephropathy and 179 with nephropathy) and 263 age-matched normal controls. The diagnosis of nephropathy was made when daily protein loss exceeded 500 mg. ACE gene polymorphism was analysed by use of polymerase chain reaction. Results. Our study revealed that the frequency of the D allele of the ACE gene was 29.3% in normal controls. The frequency of ACE DD genotype was significantly higher in type 2 diabetics compared with normal controls, (18.2 vs 9.1%, P

Clinical outcome of dialysis patients after eating star fruit ( Averrhoa carambola ) varies, but it may be fatal. In the past 10 years, 20 such patients were treated in our hospital when they developed clinical symptoms after eating the fruit or drinking star fruit juice. Their initial presentations included sudden-onset limb numbness, muscle weakness, intractable hiccups, consciousness disturbance of various degrees, and seizure. No other major events that might be responsible for these symptoms could be identified. Eight patients died, including one patient with a serum creatinine level of 6.4 mg/dL who had not yet begun dialysis. The clinical manifestations of the survivors were similar to those who died except for consciousness disturbance and seizure. Death occurred within 5 days despite emergent hemodialysis and intensive medical care. The survivors' symptoms usually became less severe after supportive treatment, and these patients subsequently recovered without obvious sequelae. The purpose of this article is to report that patients with renal failure who ingest star fruit may develop neurological symptoms and also run the risk for death in severe cases. Mortality may also occur in patients with chronic renal failure not yet undergoing dialysis.

Background Intraductal papillary-mucinous carcinoma (IPMC) of the pancreas is a newly identified clinicopathologic entity of the exocrine pancreas. It has been considered a slowly growing and less-aggressive carcinoma with a favorable prognosis. There have been only a few documents reporting its distant metastasis and cytologic features, with no report of thyroid metastasis until the present. Case A case of IPMC occurred in a 45-year-old male, who was admitted with rapid growth and tenderness of the thyroid. Abdominal computed tomography showed the typical cystic dilatation of IPMC with adjacent organ metastasis. Fine needle aspiration of the thyroid yielded papillary fronds of carcinoma cells with nuclear pleomorphism, abundant cytoplasm and prominent nucleoli in a mucinous background. Immunohistochemical findings from the skin and thyroid characterized the papillary-mucinous carcinoma as having originated in the pancreas. Conclusion This case suggests that papillary carcinoma fronds aspirated from the thyroid should be further differentiated from the primary site and that a pleomorphic nucleus in a mucinous background is a useful feature to exclude a thyroid origin. Before this, distant metastasis of IPMC to the skin and thyroid has not been reported. The prognosis of IPMC with wide, distant metastasis at an advanced stage is poor.

A total of 18 families with multiple cases of breast cancer were identified from southern Taiwan, and 5 of these families were found to carry cancer-associated germline mutations in the BRCA1 and BRCA2 genes. One novel cryptic splicing mutation of the BRCA1 gene, found in two unrelated families, was shown to be a deletion of 10 bp near the branch site in intron 7. This mutation causes an insertion of 59 nucleotides derived from intron 7 and results in a frameshift, leading to premature translational termination of BRCA1 mRNA in exon 8. Deletions of 2670delC, 3073delT and 6696-7delTC in the BRCA2 gene were found in three other breast cancer families. All three deletions are predicted to generate frameshifts and to result in the premature termination of BRCA2 protein translation. Several genetic polymorphisms in both BRCA1 and BRCA2 genes were also detected in this investigation.

Previous studies have revealed specific activations of the RET oncogene in multiple endocrine neoplasia type 2 (MEN 2) and thyroid tumors. To understand the role of the RET proto-oncogene activation in sporadic adrenal tumors, we analyzed the alterations of the RET proto-oncogene in the cysteine-rich extracellular domain (exons 6 and 10), the terminal region of the extracellular domain and transmembrane domain (exon 11) and the tyrosine kinase domain (exons 12-17) in 35 cases of adrenal tumors (including 18 Conn's syndrome, 3 Cushing's syndrome, 2 non-functional adrenocortical tumor and 12 pheochromocytomas by polymerase chain reaction-single strand conformational polymorphism and sequencing methods. One case with pheochromocytoma and one with Conn's syndrome had point mutation. We also detected the rearrangement of the RET gene by reverse transcription-polymerase chain reaction and Southern hybridization. One case with Conn's syndrome and one with Cushing's syndrome were found to harbor RET/PTC1 (RET tyrosine kinase domain rearranged with H4 gene). The above results indicate that RET proto-oncogene mutations and RET/PTC1 are involved in the pathogenesis of sporadic adrenal tumors. Mutations at codon 634 of the RET gene were also found in adrenal tumors. This suggests that the RET oncogene may also play a role in the tumorigenesis of adrenal tumors, and this possibility requires further investigation.

Pancytopenia is rare after acute hepatitis B infection. The use of lamivudine in the treatment of acute hepatitis B-associated pancytopenia in renal transplant recipients has not been documented. Herein we reported a 21-year-old woman who was infected with acute hepatitis B 6 months after renal transplantation, a condition complicated by pancytopenia. Lamivudine reversed the acute hepatitis in 1 month and the pancytopenia after 3 months, without a change in renal function. Lamivudine was maintained for 2 years without a hepatitis flare-up after 4 years.

Recombinant human erythropoietin enhances superoxide production by FMLP-stimulated polymorphonuclear leukocytes in hemodialysis patients. Recombinant human erythropoietin (rHuEPO) is a hematopoietic growth factor that has a broad spectrum of action. We have observed the in vivo and in vitro effects of rHuEPO on the superoxide production of circulating polymorphonuclear leukocytes (PMNs) in hemodialysis patients. The PMNs were separated from heparinized blood after dextran sedimentation and Ficoll-Conray centrifugation and stimulated with formyl-methionyl-leucyl-phenylalanine (FMLP), serum-treated zymosan (STZ), or phorbol myristate acetate (PMA). The in vivo study showed that rHuEPO therapy for 12 weeks enhanced the superoxide production by FMLP-stimulated PMNs (P < 0.01). However, no significant changes on superoxide production was found in either STZ- or PMA-stimulated PMNs. Simultaneous measurement of PGE2 production by PMNs in response to all three stimulants did not show any significant changes after rHuEPO therapy. The direct in vitro effect of rHuEPO on PMNs showed that rHuEPO does not enhance the superoxide production by non-stimulated PMNs. However, preincubation of rHuEPO enhanced superoxide production from FMLP- and STZ-stimulated PMNs. Our results indicate that rHuEPO enhanced FMLP-stimulated superoxide production of PMNs both in vivo and in vitro in hemodialysis patients, which may be responsible for the increased oxidant stress in hemodialysis patients after rHuEPO therapy.

Increased atrial natriuretic peptide mRNA expression in the kidney of diabetic rats. To investigate whether renal synthesis of atrial natriuretic peptide (ANP) is influenced in diabetes, we measured renal ANP mRNA levels, urine volume, urinary ANP and sodium excretion rates in streptozotocin (STZ)-induced diabetic rats. By using reverse transcription-polymerase chain reaction (RT-PCR) followed by Southern blot analysis, we found that renal cortical and outer medullary ANP mRNA levels in untreated diabetic rats were markedly increased as early as the second day after the onset of hyperglycemia and remained elevated for the entire 42-day study period. Plasma ANP concentrations in untreated diabetic rats were increased on the 42nd day, whereas plasma renin activity were suppressed. The urine volume, urinary ANP and sodium excretion rates in untreated diabetic rats were also significantly elevated on the second day and remained elevated for the entire 42-day study period. Urinary ANP excretion rates were well correlated with urine volume, and urinary sodium excretion rate in normal rats and diabetic rats on days 2, 4, 7, 14 and 42. Our results indicate that renal ANP mRNA expression is enhanced in diabetic rats, and that renal-synthesized ANP as one of regulators to handle water and sodium balance in diabetic rats is worthy of further investigation.

To clarify whether beta-cell function deteriorates with increasing albuminuria and duration of diabetes, we investigated the insulin and c-peptide response to oral glucose tolerance test in 47 healthy subjects and 75 normoalbuminuric (group 1), 30 microalbuminuric (group 2), and 35 macroalbuminuric (group 3) Type 2 diabetes mellitus patients. The total area under the insulin curve (AUCI) values of groups 1, 2, and 3 were 245 +/- 16, 193 +/- 17, and 88 +/- 8 pmol/L.h, respectively, significantly lower than that (624 +/- 34 pmol/L.h) of the healthy group. The mean total area under the c-peptide curve (AUCC-P) values of groups 1, 2, and 3, respectively, were 2.50 +/- 0.11, 2.05 +/- 0.15, and 1.73 +/- 0.07 nmol/L.h, respectively, significantly lower than that (5.47 +/- 0.19 nmol/L.h) of the healthy controls. The mean AUCI and AUCC-P values of group 3 were significantly reduced compared to those of group 1. The mean AUCI and AUCC-P values of patients with 0-5, 5-10, 10-15, and > 15 years' duration were significantly decreased compared to those of healthy subjects. The mean AUCI and AUCC-P values of patients with > 15 years' duration were significantly lower than those of patients with 0-5 years' duration. The mean hemoglobin Alc values of the three diabetic groups were not significantly different. These data suggest that beta-cell function deterioration was associated with increasing albuminuria and diabetic duration in Type 2 diabetic patients.

We have shown that epidermal growth factor (EGF) may be important in diabetic renal hypertrophy. Since EGF is the most potent mitogen for the proximal tubule, it may be relevant to the cellular hyperp

Recently, our laboratory has found a high incidence (77%) of p53 gene mutations in human functional adrenal tumors. Furthermore, the majority of mutant sites were assembled at codons 100, 102, and 249. These mutation sites are not common, and there have been no studies addressing whether or not these mutants points or mutant styles cause the p53 protein to lose function. It has been well known that p53 is a transcription factor. To examine the transcriptional activities of these mutant p53 genes from patients with functional adrenal tumors, we constructed p53 expression plasmids from tumors and paired adjacent normal adrenal gland tissues, using a transient co-transfection assay with a reporter gene in H358 cells. Wild-type p53 from normal adrenal gland tissues specifically trans-activates the expression of a chloramphenicol acetyltransferase (CAT) reporter gene in H358 cells. Three mutant p53 proteins (at codons 100, 102, and 249, respectively) from tumors showed a90% loss of transcriptional activity. One mutant at codon 68, other than at hot spots, remained at approximately 65% transcriptional activity. An immunoprecipitation assay showed that the mutant proteins of codon 68 and codon 102 could respond to the three monoclonal antibodies (PAbDO-1, PAb1620, and PAb421), indicating that there were no obvious changes in the antigenicity of the proteins. However, the mutant protein of codon 249 could not respond to the carboxy-terminus-specific antibody PAb421 and conformation-specific antibody PAb1620, indicating that there were some obvious changes in the conformation of the mutant proteins. The mutant protein of codon 100 could not be detected by immunoprecipitation assay but could be analyzed by Western blot. In a further study using a DNA-binding assay, it was shown that the loss of transcriptional activity was caused by the loss of DNA-binding ability. These results show that the p53 mutants, derived from functional adrenal tumors, actually lost DNA-binding ability and decreased the transcriptional activity. However, the role of the mutant protein in the tumorigenesis of functional adrenal tumors requires further investigation.

For assessing the role of circulating immune complexes (CIC) in acute hepatitis A, IgM- and IgG-specific CIC were determined, by C1q and conglutinin (K) assays, in 205 patients with acute hepatitis A and 60 healthy controls. The concentration of each type of CIC in patients was higher than healthy controls (P= 0.0001). CIC was a common feature of acute hepatitis A with 95.6% of cases having at least one abnormal test result. The prevalence of abnormal IgM class CIC was significantly higher than IgG class CIC. There were significantly inverse correlations between levels of IgM class CIC and interval between onset of symptoms and patient presentation. The prevalence of abnormal IgM CIC was higher in patients with higher alanine aminotransferase (P= 0.001) and patients with jaundice (P= 0.0002). In conclusion, IgM class CIC is the predominant CIC in acute hepatitis A and correlated with disease activity. CIC may play a role in the pathogenesis of acute hepatitis A.

A simple and reliable sampling method for measuring post-dialysis blood urea nitrogen (C2) has not been well established. Therefore, the effects of different methods of sampling C2 on calculating urea kinetic modeling (UKM) derived parameters were studied in patients on hemodialysis. At first, C2 values were sampled at the end of hemodialysis at a blood flow rate of 300 ml per min (blood flow rate (Qb) 300 ml per min). They were then divided into two groups. In group 1 (n = 11), C2 samples were taken after slowing down Qb to 100 ml per min for 3 min (C2-100); the blood pump was then stopped for 1 min, and C2 was again sampled (C2-100-stop). Finally, C2 was sampled with Qb restored to 100 ml per min and the venous line clamped for another 12 sec (C2-100-clamp). In group 2 (n = 11), C2 samples were collected after Qb was slowed down to 50 ml per min for 3 min (C2-50), and C2-50-stop was then measured. Finally, C2-50-clamp was measured. Using C2-clamp as a reference standard, UKM parameters were calculated using a variable volume, single pool UKM. The authors found that Kt/V calculated by C2-300, C2-100, and C2-50 overestimated the reference Kt/V by 8.4-9.1%, 5.1%, and 3%, respectively. In contrast, protein catabolic rate and time-averaged BUN were affected only minimally. Therefore, a low flow technique with a Qb of 50 ml per min for 3 min can be used for the routine estimation of C2 and UKM-derived parameters with reasonable accuracy.

The effects of recombinant human erythropoietin (rHuEPO) treatment on parathyroid function in patients on maintenance hemodialysis (HD) with secondary hyperparathyroidism (HPT) is poorly understood. We compared the levels of serum intact parathyroid hormone (PTH) and the suppressibility of PTH by intravenous calcium infusion before and after 12 weeks of rHuEPO treatment in 8 HD patients with secondary HPT. The suppressibility of PTH by calcium infusion in HD patients was also compared with that of normal subjects. After rHuEPO treatment, in HD patients hematocrit and hemoglobin levels increased significantly from 20.1 +/- 1.3% and 6.65 +/- 0.46 g/dl to 28.7 +/- 1.0% and 9.68 +/- 0.39 g/dl, respectively. The serum intact PTH levels did not change significantly (541.9 +/- 65.3 pg/ml before versus 572.9 +/- 75.3 pg/ml after rHuEPO treatment), nor did serum ionized calcium, phosphate, magnesium, aluminum, alkaline phosphatase, and 1.25(OH)2D levels. Calcium infusion significantly increased serum ionized calcium and suppressed serum PTH levels. However, the increment in serum calcium levels and the percent decrement of serum PTH showed no significant differences before and after rHuEPO treatment in HD patients. Elevations in serum calcium levels during calcium infusions were not significantly different between normal subjects and HD patients. However, the percent maximal decrement in serum PTH level was less in HD patients both before and after rHuEPO treatment than in normal subjects (-75.4 +/- 3.9 and -76.4 +/- 4.1% versus -91.4 +/- 1.4%). We conclude that rHuEPO treatment has no influence on parathyroid function in maintenance HD patients with secondary HPT. In addition, PTH secretion is less suppressed by calcium infusion in the same group of patients.

To investigate the intrarenal endothelin 1 (ET-1) synthesis in streptozocin (STZ) diabetic rats with moderate hyperglycemia, we measured plasma ET-1, renal ET-1 mRNA, and renal tissue ET-1 levels. The renal ET-1 mRNA expression progressively decreased from the 2nd to the 6th week after induction of diabetes by STZ. The renal ET-1 mRNA expression and the renal tissue ET-1 content were significantly reduced in 8 diabetic rats with a mean blood glucose level of 21.0 +/- 0.4 mM as compared with 7 normal rats sacrificed at the 6th week after STZ or citric buffer injection. The reduction of renal ET-1 and mRNA levels was ameliorated in 9 diabetic rats with a mean blood glucose level of 6.9 +/- 0.7 mM after strict glycemic control by insulin treatment. Kidney weight and glomerular filtration rate in moderately hyperglycemic rats were significantly increased as compared with normal rats at the 6th week after STZ injection. The mean plasma ET-1 levels in moderately hyperglycemic diabetic rats were not different from those of the other two groups. This study demonstrates that moderate hyperglycemia in diabetic rats is associated with a reduction in renal ET-1 synthesis. Whether decreased renal ET-1 synthesis is an adaptive phenomenon of a renal hemodynamic change during the early stage of diabetes is worthy of further investigation.

Induction of heparin-binding epidermal growth factor-like growth factor mRNA by protein kinase C activators. Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a potent smooth muscle cell mitogen of macrophage origin. To determine whether the HB-EGF gene is transcribed and regulated in mesangial cells, we measured HB-EGF mRNA levels in cultured rat mesangial cells by RNA blot analysis. A 2.5-kb HB-EGF mRNA was detected in unstimulated mesangial cells. The protein kinase C activator 12-O-tetradecanoylphorbol 13-acetate (TPA) increased HB-EGF mRNA levels by 15-fold in mesangial cells, and this induction of HB-EGF mRNA by TPA was both time- and dose-dependent. HB-EGF mRNA could also be stimulated by 10% fetal calf serum, ionomycin, thrombin, and endothelin-1. Staurosporine, a protein kinase C inhibitor, abolished the induction of HB-EGF mRNA by TPA and serum. To determine whether HB-EGF is mitogenic for mesangial cells, we transfected COS cells with HB-EGF expression plasmids. Culture medium from COS cells transfected with these plasmids increased 3 H-thymidine incorporation in mesangial cells in a dose-dependent manner. To our knowledge, this is the first report that HB-EGF is expressed in renal cells. This inducible transcription of HB-EGF suggests that it may have an autocrine role in mesangial cell proliferation in kidney disease.

The present study was to determine whether low-density lipoprotein (LDL) and oxidized LDL (Ox-LDL) modulate the heparin binding-epidermal growth factor like growth factor (HB-EGF) gene expression in rat mesangial cells (RMC). Using Northern blot analysis, LDL and Ox-LDL stimulated the expression of RMC HB-EGF mRNA in a time- and concentration-dependent manner, and the stimulatory effect of Ox-LDL lasted longer than LDL. In addition, a protein kinase C (PKC) inhibitor-staurosporine and a PKC-depletion condition abolished both of the stimulatory activities of LDL and Ox-LDL, while H-8 (a protein kinase A inhibitor) and cAMP-antagonist (cyclic adenosine-3′:5′-monophosphothioate) had little effect. Our data indicate that LDL and Ox-LDL enhance HB-EGF gene expression and both via the PKC pathway in RMC. As HB-EGF is a mitogen for RMC, our results suggest that lipoproteins may regulate RMC function by inducing HB-EGF gene expression and thus contribute to glomerular injury.

OBJECTIVE To determine the urinary endothelin-1-like immunoreactivity (ET- 1-LI) in non-insulin-dependent diabetes mellitus (NIDDM) patients and toinvestigate whether urinary ET-l-LI excretion is elevated in patients with albuminuria. RESEARCH DESIGN AND METHODS Urinary ET-l-LI substance was determined byradioimmunoassay in 45 normoalbuminuric and 28 albuminuric NIDDM patients. RESULTS The mean amounts of 24-h ET-1 -LI excretion in NIDDM patients with normoalbuminuria and albuminuria were 154.9 ± 13.5 and 174.4 ± 12.9 ng/day, respectively. The latter was significantly higher thanthat of the 40 normal control subjects (111.8 ± 7.9 ng/day, P < 0.01). CONCLUSIONS The increase in urinary ET-l-LI substance excretion in patients with albuminuria suggests that ET-1 may be a pathogenetic factor in diabetic nephropathy.

To clarify gene alterations in functional human adrenal tumors, we performed molecular analysis for p53 abnormalities in 23 cases with adrenal neoplasms. The immunohistochemical study with anti-p53 monoclonal antibody pAb1801 demonstrated that 10 of 23 (43.5%) cases overexpressed p53 protein in the tumor cells. Using a polymerase chain reaction-single strand conformation polymorphism study, 5 of 6 (83.3%) pheochromocytoma tissues (1 malignant and 5 benign) and 11 of 15 (73.3%) adrenocortical adenomas (2 with Cushing's syndrome and 13 with primary aldosteronism, all benign) showed an apparent electrophoretic mobility shift between the tumor and its paired adjacent normal adrenal tissue. Such differences were detected in exon 4 (12 cases), exon 5 (2 cases), and exon 7 (3 cases). The types of these mutations in exon 4 were a substitution from threonine (ACC) to isoleucine (ATC) at codon 102 in 5 cases, from glutamine (CAG) to histidine (CAC) at codon 104 in 1 case, from glycine (GGG) to alanine (CGG) at codon 117 in 1 case, from glutamate (GAG) to glutamine (CAG) at codon 68 in 1 case, and single base changes resulting in a premature stop codon at codon 100 in 2 cases. A 2-basepair deletion at codon 175 in exon 5 resulting in a frame shift was identified in 1 case. A single point mutation was identified, resulting in the substitution of glutamine (CAG) for arginine (CGG) at codon 248 of exon 7 in 1 case. A single basepair deletion at codon 249 resulted in a frame shift in 2 cases. There was 1 case with malignant pheochromocytoma that combined a single point mutation in exon 4 and a single base deletion in exon 7. Only 2 of 23 cases showed a loss of a normal allele encoding in the p53 gene. Northern blot analysis with 1.8-kilobase p53 cDNA revealed that p53 mRNA was overexpressed in 6 cases. Our results indicate that high frequencies of p53 gene mutation, especially in exon 4, exist in functional adrenal tumors. As p53 protein is a regulator of guanine nucleotide synthesis, the loss of normal inhibitory regulation by the p53 mutation would serve to increase the availability of GTP for the transduction of signals essential for increased cell growth and hormone expression in the adrenal tumors. These findings suggest that the p53 gene mutation may play a role in the tumorigenesis of benign and functional human adrenal tumors.

To assess whether hepatitis C virus infection was a risk factor for the development of non-alcoholic liver cirrhosis, antibody to hepatitis C virus (anti-HCV; detected by a second generation HCV enzyme immunoassay), hepatitis B surface antigen (HBsAg; detected by radioimmunoassay) were tested in 150 cirrhotics and 150 sex-matched and age-matched healthy controls. The prevalence of anti-HCV and HBsAg in cirrhotics was higher than in controls (22.0%, 73.3% vs. 2%, 18.7%; P = 0.001). The prevalence of anti-HCV in HBsAg-negative cirrhotics (45.0%) was higher than that in HBsAg-positive patients (13.6%; P = 0.001). Both the anti-HCV and carriage of HBsAg were associated significantly with liver cirrhosis, showing odds ratio of 12.0 for HBsAg carriers and 13.8 for patients with anti-HCV. Compared with those without HBsAg and anti-HCV, there was a significantly positive linear trend for developing cirrhosis with the presence of HBsAg alone (odds ratio = 19.9), anti-HCV alone (odds ratio = 49.0), and those positive for HBsAg and anti-HCV (odds ratio = 81.8) (P = 0.00001). The population-attributable risk for developing liver cirrhosis was estimated as 10.8% for anti-HCV alone, 55.2% for HBsAg alone, and 9.4% for both anti-HCV and HBsAg in southern Taiwan. In conclusion, this study shows that hepatitis B and C virus infection act independently and synergistically in the development of non-alcoholic liver cirrhosis among Chinese in Taiwan.

The present study was designed to determine whether atrial natriuretic polypeptide (ANP) is synthesized in the human adrenal gland and, if so, to investigate the ANP content of adrenal tissue and the ANP mRNA changes in patients with primary aldosteronism. A considerable amount of human alpha ANP-like immunoreactive substances was extracted from the remnant adrenal glands of three patients with primary aldosteronism (1.44, 1.0, and 0.77 pmol/g wet tissue; mean +/- SD, 1.07 +/- 0.28 pmol/g) and the adrenal glands of three kidney donors for transplantation (0.93, 0.58, and 0.27 pmol/g wet tissue; mean +/- SD, 0.59 +/- 0.27 pmol/g). High performance gel permeation chromatographic analysis coupled with a RIA of the tissue extract showed that the molecular form of ANP in the adrenal gland was the precursor form, i.e. human gamma ANP. An in situ hybridization study using an ANP cRNA probe indicated that the ANP mRNA was localized mainly in the medullary area of the gland. Northern blot analysis, using ANP cDNA as a probe, detected ANP mRNA in the adrenal gland. Furthermore, the level of ANP mRNA in the adrenal glands of patients with primary aldosteronism was obviously elevated compared to that in the kidney donors. Our results were the first to indicate that ANP is synthesized in the human adrenal medulla, and such medullary ANP synthesis increases in patients with hypermineralocorticoidism. These facts support the proposal that extraatrial (medullary) ANP synthesis might act in a paracrine or endocrine manner to regulate water and electrolyte homeostasis.

Because aluminum hydroxide, as a phosphate binder, lowered intestinal zinc absorption, we studied the effects of calcium carbonate (CaCO3) and calcium acetate (CaAc), two other phosphate binders, on intestinal Zn absorption in nine patients on hemodialysis and in 11 controls by measuring 1- and 2-hour serum Zn levels after oral administration of 50 mg of elemental Zn as Zn gluconate with or without concomitant administration of 2 g CaCO3 (800 mg elemental Ca) or 3 g CaAc (750 mg elemental Ca). Fasting serum Zn levels were not different between patients and controls (14.0 +/- 2.3 v 14.1 +/- 1.2 mumol/L [91.8 +/- 14.9 v 92.3 +/- 8.0 micrograms/dL]), but the area under the curve of serum Zn increment (AUC) 2 hours after an oral Zn challenge without or with either of two of phosphate binders used was significantly smaller in patients than in controls (P less than 0.05). The AUC after concomitant administration of Zn with CaCO3 did not differ from that of Zn alone in either patients or controls, but it was significantly less in Zn with CaAc than in Zn alone or in Zn with CaCO3 in both groups. The results demonstrate that intestinal Zn absorption after an oral Zn challenge decreased in patients on hemodialysis and concomitant administration of CaAc, but CaCO3 did not decrease intestinal Zn absorption in either group.

To characterize epidermal growth factor-related transforming growth factors in the urine of patients with hepatocellular carcinoma, gel filtration with Bio-Gel P-30 was performed in seven hepatocellular carcinoma patients and seven sex-matched and age-matched healthy controls. Distinct profiles of soft agar growth assay in the hepatocellular carcinoma patients and the normal controls were seen. Three peaks (A, B and C) in the urine were examined. Peak C in most hepatocellular carcinoma patients was higher than that in healthy controls. Similar profiles were detected with epidermal growth factor radioreceptor assay and cellular DNA synthesis assay. This result might indicate that transforming growth factors with low molecular weight were found in the urine of hepatocellular carcinoma patients. An exceptional HCC patient had an additional peak (A') that corresponded to the high molecular weight protein. We concluded that there were transforming growth factors with functional activity in the urine of patients with hepatocellular carcinoma.

Circulating immune complexes (CIC), complement and alpha-fetoprotein (AFP) were detected in 93 hepatitis B surface antigen (HBsAg)-positive patients with hepatocellular carcinoma (HCC), 16 patients with liver cirrhosis (LC) and 54 healthy controls. The CIC and complements were significantly higher in HCC patients than in LC patients. The complement and polyethylene glycol(PEG)-CIC in HCC patients with LC were higher than those in LC only (P less than 0.0001). The complement levels in LC patients were significantly lower than in controls. There was no difference in C3 and C4 between HCC patients and controls, while the C3 proactivator was higher in HCC patients (P less than 0.02). The C1q-CIC was higher in HCC and LC patients when compared to controls (P less than 0.0001). In patients with HCC, there was no difference in the CIC and complement levels between patients with cirrhosis and those without. There were inverse correlations between C1q-CIC and C3 (P less than 0.05), C1q-CIC and C4 (P less than 0.04). The mean level of 3% PEG-CIC and C1q-CIC increased significantly as AFP elevated, but decreased as AFP was higher than 1599 ng/ml (P less than 0.05). These results imply that CIC increase with tumor growth but further tumor burden may result in a fall in CIC, there was a shifting of CIC from complement-fixing to non-complement-fixing as AFP increased gradually.

Using the immunoperoxidase and immunogold methods with specific antibody, we studied the atrial natriuretic polypeptide (ANP) in seven tumor tissues of six patients with adrenal pheochromocytoma. Light microscopically, the reaction product for ANP was observed in all seven tumor tissues. Intracytoplasmic immunoreaction product for ANP was finely granular. In four cases studied with the electron microscope, the immunogold stain for ANP was demonstrated in secretory granules of the tumor cells. A considerable amount of alpha-hANP immunoreactive substance was also extracted from two tumor tissues (67.2 and 28.7 pg/mg wet tissue). This is the first report of the human adrenal pheochromocytoma that contains immunoreactive ANP. These findings provide additional evidence for the multisecretory APUD cells of neural crest origin.

Decreased renal Na-K ATPase activity in ureteral obstruction contributes to tubular sodium reabsorption defect in obstructive nephropathy. The integrated changes on the enzyme activity, protein number, and mRNA level of renal cortical Na-K ATPase, in response to bilateral or unilateral ureteral obstruction (BUOUUO), were studied in rabbits. Ouabain-sensitive Na-K ATPase activities of renal cortex were significantly decreased at 24 h after BUO and further decreased at 48 h. The unobstructed contra-lateral kidney had significantly higher Na-K ATPase activity compared to the obstructed side. Immunoblots of Na-K ATPase alpha and beta subunits protein were both decreased at 24 h of BUO and further decreased at 48 h. The levels of Na-K ATPase beta subunit mRNA showed to be significantly decreased at 12 h after obstruction and further decreased at 24 and 48 h. However, the levels of alpha subunit mRNA were not changed as that of beta subunit throughout the study period. This study also used a newly developed method for release of obstruction. All the parameters studied above recovered to variable extents after release of the ureteral obstruction. In summary, decreases in Na-K ATPase activity, protein, and mRNA in obstructed kidney are specific cellular responses to ureteral obstruction. The degree of down-regulation is related to the duration of obstruction. The reduced activity of Na-K ATPase can be explained by decreased enzyme protein. However, the discordant findings in Na-K ATPase subunits protein amounts and mRNA changes suggest that renal Na-K ATPase subunits have different cellular regulatory processes to obstruction, in which transcriptional, translational and even intra-cytoplasmic processing may be involved.

This study aimed to investigate sex differences in relation to hepatitis B e antigen (HBeAg) and serum alanine aminotransferase (ALT) levels in chronic asymptomatic hepatitis B virus (HBV) infection. HBeAg and ALT level were determined in 636 asymptomatic hepatitis B surface antigen carriers. There was no significant sex differences in the age-adjusted prevalence of HBeAg. Abnormal ALT level (>45 IU/l) was more frequent in carriers with HBeAg (17.5% vs 7.6%; P = 0.001). Multivariate analysis indicated that male sex (odds ratio, 2.0; 95% confidence interval, 1.1-3.6) and HBeAg (odds ratio, 2.6; 95% confidence interval, 1.6-4.3) were independent risk factors for abnormal ALT levels. Male sex and HBeAg-positivity are independent risk factors for abnormal ALT activity in chronic HBV infection. This observation may be related to sex differences in chronic HBV infection.

Both reactive oxygen species (ROS) and endothelin-1 (ET-1) have been implicated in the pathophysiology of diabetic nephropathy. The interrelationship between them, however, has not been documented in this disease. To determine whether ROS regulates ET-1 production in diabetic kidneys, we examined the in vitro and in vivo effects of ROS donors and scavengers on ET-1 production of diabetic rat glomeruli. For in vitro study, the glomeruli were isolated with a sieving method from streptozotocin-induced diabetic rats and killed at 1 week, 1 month, and 3 months, respectively. Superoxide was measured by a spectrophotometer, and ET-1 was measured by radioimmunoassay. The results demonstrated that the basal production levels of superoxide and ET-1 were higher in diabetic glomeruli than in normal glomeruli in vitro. There was a positive correlation between the production of superoxide and ET-1 in diabetic glomeruli. The basal ET-1 production was markedly attenuated by ROS scavengers including superoxide dismutase, catalase, dimethyl sulf- oxide, and deferoxamine in diabetic glomeruli. Exogenous ROS generated by xanthine/xanthine oxidase significantly enhanced ET-1 generation by both diabetic and normal glomeruli. A high glucose concentration (500 mg/dL) in vitro increased ET-1 production by normal glomeruli but not diabetic glomeruli, and insulin partly suppressed ET-1 production by diabetic glomeruli. The in vivo study demonstrated that when diabetic rats were injected daily with superoxide dismutase or catalase after diabetes was induced, the basal production of ET-1 was markedly attenuated after 1 week and 1 month, respectively. These results indicate that exogenously or endogenously derived ROS can enhance ET-1 production by diabetic rat glomeruli and that ROS scavengers suppress ET-1 production both in vitro and in vivo. The effects of ROS on ET-1 production of diabetic glomeruli may be partly caused by the effect of hyperglycemia or insulin deficiency. (J Lab Clin Med 2000;135:309-15)

Oxygen free radicals have been implicated in mediating diabetic complications, and patients with diabetic nephropathy frequently show increased levels of circulating and oxidized low–density lipoproteins (LDL). In the present study, we measured the superoxide production of glomeruli isolated from poorly controlled diabetic (streptozotocin) rats sacrificed 1 week and 1, and 3 months after the induction of diabetes. The animals were stimulated with native and oxidized LDL isolated from normal humans with normolipidemia. The superoxide ion was measured by using a spectrophotometer. The results demonstrated that the poorly controlled diabetic rat glomeruli showed a significantly higher production of superoxide than normal glomeruli under basal conditions, and this production increased further with the progression of diabetes. Stimulation with either LDL or oxidized LDL enhanced superoxide production by diabetic glomeruli, with oxidized LDL being more potent than LDL. Our results suggest that oxidized LDL may play important roles in the pathogenesis of diabetic nephropathy through enhanced generation of oxygen free radicals.

Increased nitric oxide synthase mRNA expression in the renal medulla of water-deprived rats. Background Experiments were performed to investigate whether renal nitric oxide synthase (NOS) mRNA and protein expression are responsive to the alteration of body volume. Methods Four days of water deprivation (WD) was initiated in 16 male Wistar rats, and 16 normal rats (NC) served as the control group. Neuronal NOS (nNOS), endothelial NOS (eNOS), and inducible NOS (iNOS) mRNAs and immunoreactivity were measured by reverse transcription-polymerase chain reaction (RT-PCR) followed by Southern blot hybridization and immunohistochemistry, respectively. Plasma angiotensin II, vasopressin, and atrial natriuretic peptide (ANP) concentrations were measured by radioimmunoassay. Results The four-day WD increased plasma sodium and osmolality levels, but severely decreased daily urine sodium excretion and urine volume. Plasma angiotensin II and vasopressin concentrations were increased, but the plasma ANP level was significantly decreased in WD rats. nNOS, eNOS, and iNOS mRNA levels were increased by 5.2-, 3.3-, and 3.4-fold in the outer medulla and 1.7-, 1.5-, and 1.8-fold in the inner medulla, whereas no significant difference was found in the renal cortex of WD rats as compared with NC rats. Additionally, immunohistochemistry revealed that the immunostaining intensity of nNOS, eNOS, and iNOS was clearly enhanced in the medullary thick ascending limb, proximal straight tubule, inner medullary collecting duct, and proximal convoluted tubule in WD rats. Kidney angiotensin II content as well as renin mRNA levels in renal cortex, outer medulla, and inner medulla in WD rats were apparently increased. Conclusions Our results indicate that the increases of nNOS, eNOS, and iNOS synthesis in the kidney, particularly in the renal medulla, may have a role in the adaptation of renal function to volume depletion in the face of an increase of systemic and intrarenal vasoconstrictive substances.

Induction of heat shock protein 70 protects mesangial cells against oxidative injury. The heat shock response is an immediate cellular response to elevated temperatures and other types of injury that consists of the synthesis of so-called heat shock protein (hsp). This study was designed to investigate the production and the protective role of the 70kDa hsp (hsp70) in cultured rat mesangial cells. When mesangial cells undergo thermal (45°C, 15 min) stimulation, they express hsp70 mRNA expression and increased hsp70 protein production. Following this, Northern blots show an enhanced gene expression of hsp70 at one hour that reached a maximum by 12 hours after heat shock. The hsp70 protein production, estimated by Western blots, was detectable 12 hours after heat shock and reached a maximum by 36 hours. Oxidative injury generated by xanthine and xanthine oxidase inhibited cell survival and cellular proliferation, as measured by trypan blue exclusion and [ 3 H]-labeled thymidine uptake. It did not affect hsp70 mRNA expression. Furthermore, when mesangial cells were preconditioned by heat shock, subsequent oxidative injury caused less inhibition of cell survival and cellular proliferation. Pretreatment of cells with quercetin, a transcription inhibitor, abolished the protective effect of heat shock on subsequent oxidative injury. We conclude that heat shock, not oxidative injury, induces hsp70 in mesangial cells, and this induction of hsp70 protects mesangial cells against subsequent oxidative injury.

Our previous study demonstrated that human adrenal medulla is a site of atrial natriuretic peptide (ANP) synthesis. To further evaluate the role of adrenal ANP in body fluid homeostasis, we investigated the changes in adrenal ANP in rats receiving deoxycorticosterone acetate (DOCA)-salt treatment. In situ hybridization and immunohistochemical study showed that adrenal ANP messenger RNA (mRNA) and ANP-like immunoreactivities (ANP-LI) were mainly localized in the zona glomerulosa and medulla of vehicle-treated rats. DOCA-salt treatment activated ANP mRNA and peptide expression in all adrenal zones, especially in the zona fasciculata/reticularis from 12 h to the entire 8-day study period. Using a semiquantitative RT-PCR technique, the relative quantities of ANP mRNA in the adrenals of the DOCA-salt-treated group were significantly increased from 1 to 8 days, whereas the adrenal weights of DOCA-salt-treated rats were significantly decreased from day 2 to day 8. Our results are the first to indicate that ANP i...

Endothelin-1 (ET-1) is a potent vasoconstrictive peptide with diverse physiologic actions and has been considered to be involved in the pathogenesis of hypertension. We sought to investigate the role of renal synthesis of ET-1 in the regulation of daily sodium homeostasis and the possible contribution of renal synthesized ET-1 in the pathogenesis of essential hypertension (EHT). Urinary ET-1–like immunoreactivity (ET-1-Ll) was measured by a radioimmunoassay after extraction in 23 EHT patients without detectable target organ damage, and in 11 normotensive controls. All study subjects received a controlled diet during an 8-day study period. Urinary and blood samples were collected by four sampling periods/day from the 4th to 6th days, and on the 7th day, study subjects were given an intravenous infusion of 1250 mL normal saline over 2 h. In the basal state, the urinary sodium and ET-1-Ll excretions showed diurnal patterns in both the normal and hypertensive groups, and urinary ET-1-Ll excretion rate correlated well with urinary sodium excretion rate. There were no differences found in plasma ET-1 levels, urinary ET-1-Ll, and sodium excretion rates between the control and hypertensive groups. After saline infusion, ten hypertensive patients showed nonexaggerated natriuresis, and the 24-h urinary ET-1-Ll excretion (47.0 ± 4.0 pmol/day), collected during the day of saline infusion, was significantly lower than that of the control group (86.3 ± 10.0 pmol/day) or the exaggeratedly natriuretic hypertensive patients (91.7 ± 8.4 pmol/day). Our results suggest that renal ET-1 may be responsible for the renal handling of sodium homeostasis, and alteration of renal ET-1 synthesis may be a contributory factor in the pathogenesis of essential hypertension and salt sensitivity.

For assessing the role of circulating immune complexes (CIC) in chronic hepatitis B virus (HBV) infection, CICs containing IgM, IgG, and HBsAg were determined by C1q and conglutinin (K) assays in 216 patients with chronic HBV infection and 54 healthy controls. The concentration of each type of CIC in patients is higher than in controls (P = 0.0001). CIC is a common feature of chronic HBV infection with 95.8% of cases having at least one abnormal test result. At least one type of HBsAg-CIC is positive in 54.2% of patients. HBsAg-CIC positivity is associated with HBeAg positivity (P = 0.0001), higher aminotransferase levels (P < 0.002), and younger age (P = 0.001). IgG-CIC or IgM-HBsAg-CIC correlates with higher aminotransferase activity (P = 0.001). In conclusion, HBsAg-CIC correlates with HBV replication. IgG-CIC and/or IgM-HBsAg-CIC correlate with disease activity. Immune-mediated injury may play a role in the pathogenesis of chronic HBV infection.

To assess the clinical relevance of transforming growth factor-beta 1 (TGF-beta 1) in the urine of patients with hepatocellular carcinoma (HCC), TGF-beta 1 was measured, by radioimmunoassay, in 140 patients with HCC, 50 cirrhotic patients, 30 patients with chronic active hepatitis, and 50 healthy controls. The results indicate that there were significantly increased urinary TGF-beta 1 levels in patients with HCC. Raised TGF-beta 1 levels were associated, in a dose-related fashion, with increased risk for development of HCC (odds ratio, 1.05, 95% confidence interval, 1.03-1.07). HCC patients with raised TGF-beta 1 levels had shorter survival than those with normal TGF-beta 1 levels (p = 0.038). TGF-beta 1 levels decreased after successful anticancer therapy (p < 0.0001). There was an inverse correlation between TGF-beta 1 and serum alpha-fetoprotein (AFP) (r = -0.199, p < 0.04). Receiver operating characteristics (ROC) curve analysis indicated that parallel determination of TGF-beta 1 and AFP significantly increased the sensitivity and diagnostic accuracy, with a high specificity. In conclusion, raised urinary TGF-beta 1 was associated with HCC development. It is a predictor of poor prognosis, and a tumor marker for diagnosis and therapeutic follow-up of HCC.

Evidence indicates that the glomerular injuries and renal hemodynamic abnormalities in hyperlipidemia are caused by the interaction of low-density lipoprotein (LDL) and oxidized LDL (Ox-LDL) with mesangial cells. Experiments were designed to investigate whether the synthesis of mesangial cell endothelin-1 (ET-1), a potent renal vasoconstrictor and mitogen for mesangial cells, is modulated by LDL and Ox-LDL. Using competitive semi-quantitative reverse transcription polymerase chain reaction (PCR), we report that the expression of cultured rat mesangial cell ET-1 mRNA was increased after treatment with Ox-LDL but not native LDL. Ox-LDL stimulated the release of ET-1 peptide into the culture medium in a time- and concentration-dependent manner. The maximal effect was observed at a concentration of 100 microg/ml, and a higher dose of Ox-LDL was found to be cytotoxic to the mesangial cells. Our results suggest that ET-1 released by Ox-LDL stimulation may be an important pathogenetic factor contributing to the renal hemodynamic alterations and progressive chronic renal diseases induced by hypercholesterolemia.

To assess the serum alanine aminotransferase (ALT) activity in relation to hepatitis B virus (HBV) and hepatitis C virus (HCV) infections among blood donors, antibodies to HCV (anti-HCV) and hepatitis B surface antigen (HBsAg) were detected in 400 blood donors with normal ALT level (< or = 750 mumol/s per liter), and 76 blood donors with raised ALT level. The prevalence of anti-HCV (10.5%) and HBsAg (28.9%) in the latter was higher than that (2.0% and 17.5%, respectively) in the former (p < 0.001 and p < 0.03, respectively). There was a trend that indicated that the risk of anti-HCV positivity increased with increasing age (p < 0.001). Thirty of 76 (39.5%) donors with raised ALT level were positive for anti-HCV or HBsAg. Compared with HBsAg-positive donors, donors with anti-HCV had higher serum ALT levels (p < 0.01) and greater mean age (p < 0.01). Multivariate analysis indicated that both anti-HCV (odds ratio: 6.2; 95% confidence interval: 2.2-17.8) and HBsAg (odds ratio: 2.2; 95% confidence interval: 1.3-3.9) were significantly associated with raised serum ALT activity. The estimated population-attributable risk was 8.6% for anti-HCV, and 13.8% for HBsAg. In conclusion, although HBV and HCV infections are independent risk factors of raised ALT activity among blood donors, they play a minor role in the etiology of raised ALT activity.

For assessing the role of circulating immune complexes (CICs) in acute hepatitis B, CICs containing HBsAg, IgM, and IgG were determined, by C1q and conglutinin (K) assays, in 242 patients with acute hepatitis B and 60 healthy controls. CIC is a common feature of acute hepatitis B with 90.9% of cases having at least one abnormal test result. Patients with shorter interval (1 week) between onset of symptoms and patient presentation have significantly higher frequency of abnormal IgM class CIC, HBsAg-specific CIC, and higher frequency of raised alanine aminotransferase activity (30-fold upper limit of normal). The prevalence of raised alanine aminotransferase in patients with CIC containing HBsAg and IgM is higher than those without (P = 0.001). There is significant association between HBsAg-CIC and C1q-CIC. In conclusion, HBsAg-CIC and IgM class CIC correlate with disease activity. C1q-binding CIC is the predominant CIC that may play a role in the pathogenesis of acute hepatitis B.

This study aimed to assess the effects and interaction between hepatitis B virus and hepatitis C virus infection on the development of chronic hepatitis.Anti-HCV and HBsAg were detected in 125 histology-proven chronic hepatitis and 250 sex-matched and age-matched healthy controls.The prevalences of anti-HCV (24.8%) and HBsAg (68.0%) in patients were higher than in controls (2.4% and 18.0%, respectively; each p0.0001). Univariate analysis showed that anti-HCV and HBsAg were strongly associated with the development of chronic hepatitis. Calculation of synergy index and Mantel extension test for trend indicated that there was additive effect modification between HCV and HBV. Multivariate analysis indicated that anti-HCV (odds ratio, 46.1; 95% confidence interval, 9.1-233.2) and HBsAg (odds ratio, 25.8; 95% confidence interval (9.3-67.2) were independent risk factors of chronic hepatitis. The population-attributable risk was estimated as 15.6% for anti-HCV alone, 52.4% for HBsAg alone and 6.8% for both anti-HCV and HBsAg. The frequency of chronic active hepatitis in patients with anti-HCV alone (100%) was higher than in patients with HBsAg alone (75%, p0.001).HCV and HBV infections are risk factors of chronic hepatitis. They act independently and probably with additive effect modification.

To assess the role of circulating immune complexes (CIC) in chronic hepatitis C virus (HCV) infection, the relative frequency of CIC was determined in 60 patients with chronic hepatitis C alone, 19 patients co-infected with hepatitis B and C, 15 asymptomatic HCV carriers, and 54 healthy controls. Levels of CIC were determined with immunoglobulin-specific C1q-binding and conglutinin (K)-binding immune complex assays. Although there was no statistical difference in the levels of each type of CIC between asymptomatic HCV carriers and healthy controls, elevated levels of CIC containing IgM and IgG were common in patients with chronic HCV infection. Compared to patients with hepatitis C alone, patients co-infected with hepatitis B and C have a higher frequency of abnormal IgM-containing CIC and significantly higher levels of IgM-containing CIC. CIC levels in patients with chronic active hepatitis were significantly higher than those in patients with chronic lobular hepatitis or chronic persistent hepatitis. In conclusion, although CIC containing IgM and IgG were common in patients with chronic hepatitis C, abnormal IgM-containing CIC are the major types of CIC in patients co-infected with hepatitis B and C. An immune-mediated mechanism may play a role in the pathogenesis of chronic hepatitis C.

For assessing the role of circulating immune complexes (CIC) in chronic hepatitis C, the relative frequency of CIC was determined in 54 patients with chronic hepatitis C, 15 asymptomatic hepatitis C virus (HCV) carriers, and 54 healthy controls. IgM and IgG containing CIC were studied using both C1q and conglutinin (K) in an immunoglobulin-specific solid-phase enzyme immunoassay. CIC were a common feature of chronic hepatitis C with 96.3% of patients with at least one abnormal test result. The prevalence of elevated IgG-K, IgM-K, IgG-C1q, and IgM-C1q CIC was 70.3%, 50.0%, 64.8%, and 35.1%, respectively. The prevalence of IgG class CIC was higher than IgM class CIC (P = 0.038 for K-CIC and P = 0.01 for C1q-CIC, respectively). There is correlation between IgG-K CIC and IgG-C1q CIC (r = 0.445, P = 0.002), IgG-K CIC and IgM-C1q CIC (r = 0.348, P = 0.020), IgM-K CIC and aspartic aminotransferase (r = 0.321, P = 0.015), IgM-K CIC and alanine aminotransferase (r = 0.301, P = 0.027). Compared to patients with chronic persistent hepatitis and chronic lobular hepatitis, patients with chronic active hepatitis have a higher prevalence of elevated IgG-K CIC (77.2% vs. 40.0%, P = 0.029) and IgM-K CIC (56.8% vs. 20.0%, P = 0.038). The concentration of IgG-K, IgM-K, and IgM-C1q CIC in the former was significantly higher than that in the latter, respectively. In conclusion, IgG class CIC is the major type of CIC in chronic hepatitis C.(ABSTRACT TRUNCATED AT 250 WORDS)