Inhibition of estrone sulfatase and proliferation of human breast cancer cells by nonsteroidal (p-O-sulfamoyl)-N-alkanoyl tyramines

Estrogen levels in breast tumors of postmenopausal women are as much as 10 times higher than estrogen levels in plasma, presumably due to in situ formation of estrogen. The major source of estrogen in breast cancer cells may be the conversion of estrone sulfate to estrone by the enzyme estrone sulfatase. Thus, inhibitors of estrone sulfatase have potential for the treatment of estrogen-dependent breast cancers. Several steroidal agents have been developed that are potent estrone sulfatase inhibitors, most notably estrone-3-O-sulfamate. However, these compounds may be metabolized to forms that have undesired actions, including estrogenicity. To avoid the problems associated with a potentially active steroid nucleus, we designed and synthesized a series of (p-O-sulfamoyl)-N-alkanoyl tyramines as nonsteroidal estrone sulfatase inhibitors. These nine compounds differ in the length of their alkanoyl chains. We tested the ability of the (p-O-sulfamoyl)-N-alkanoyl tyramines to inhibit: (a) estrone sulfatase activity in intact cultures of human breast cancer cells (MDA-MB-231); and (b) the growth of estrogen-dependent human breast cancer cells (MCF-7). All of the test compounds (1 microM) inhibited the estrone sulfatase activity of intact MDA-MB-231 cells; however, compounds with a longer alkanoyl chain were more effective than those with a shorter chain. Dose-response analysis indicated an IC50 of 350 nM for (p-O-sulfamoyl)-N-tetradecanoyl tyramine for the inhibition of MDA-MB-231 estrone sulfatase activity. The inhibition of MDA-MB-231 cell estrone sulfatase activity by this compound was found to be irreversible. Cell proliferation assays involved the treatment of estrogen-deprived MCF-7 cells with test compounds (10 microM) in the presence of estrone sulfate (1 microM) as the only source of estrogen. All compounds inhibited cell proliferation to some extent, but the longer-chain analogues again were more effective. Dose-response analysis indicated an IC50 of 38 nM for (p-O-sulfamoyl)-N-tetradecanoyl tyramine for the inhibition of MCF-7 cell proliferation. Our data indicate the utility of (p-O-sulfamoyl)-N-alkanoyl tyramines for the inhibition of breast cancer cell estrone sulfatase activity. Furthermore, our data support the concept that nonsteroidal estrone sulfatase inhibitors may be useful as therapeutic agents for estrogen-dependent breast cancers.

Xanthomonas maltophilia peritonitis in uremic patients receiving continuous ambulatory peritoneal dialysis

Xanthomonas maltophilia peritonitis has been only occasionally reported in patients receiving continuous ambulatory peritoneal dialysis. We present a series of six cases of peritonitis caused by such bacteria, accounting for 1.5% of all peritonitis episodes encountered in our renal unit over the past 5 years. Recent bacterial peritonitis treated with broad-spectrum antibiotics was the major risk factor, and the outcome was poor with medical treatment alone. Secondary peritonitis, especially fungal, was common and probably related to the prolonged course of antibiotics. All patients eventually required removal of the catheter, either because the effluent failed to clear up or because of secondary peritonitis. We suggest that X maltophilia peritonitis be treated with double antibiotics as soon as it is diagnosed. To prevent the development of superimposed infection after prolonged administration of antibiotics, the Tenckhoff catheter should be removed if the peritonitis fails to respond to a short course of antibiotics.

Memory enhancement mediated by the steroid sulfatase inhibitor (p-O-sulfamoyl)-N-tetradecanoyl tyramine

The intent of this study was to determine whether altering the metabolism of neurosteroids via blockade of the enzyme, steroid sulfatase, could enhance memory retention in rats. The steroid sulfatase inhibitor p-O-(sulfamoyl)-N-tetradecanoyl tyramine (DU-14) was administered alone and in combination with the neurosteroid dehydroepiandrosterone sulfate (DHEAS) to rats which were then tested for the reversal of scopolamine-induced amnesia. A single 30 mg/kg IP dose of DU-14 produced a significant inhibition of steroid sulfatase activity in both brain (14.8%), and liver (85.2%) tissues, 24 hours following administration. In a passive avoidance test, DU-14 enhanced the reversal of amnesia by DHEAS. These results suggest that steroid sulfatase inhibition can potentiate the memory enhancing properties of DHEAS.

Enhancement of hippocampal acetylcholine release by the neurosteroid dehydroepiandrosterone sulfate: an in vivo microdialysis study

The effect of dehydroepiandrosterone sulfate (DHEAS) administered i.p. on the release of acetylcholine (ACh) from the hippocampus of anesthetized rats was examined using in vivo microdialysis. DHEAS significantly increased ACh release above the pre-treatment levels for all doses tested. The administration of 100 mg/kg significantly enhanced ACh release greater than 4-fold when compared to the saline-treated group 80 min following drug administration. This study is the first to demonstrate that the neurosteroid DHEAS, a negative allosteric modulator of the GABAA receptor, can enhance the release of ACh from neurons in the hippocampus.

Synthesis and sulfatase inhibitory activities of non-steroidal estrone sulfatase inhibitors

About one-third of breast cancers are classified as estrogen-dependent breast cancers. In the past 10 years, numerous reports have suggested the importance of estrone sulfate and estrone sulfatase in regulating the supply of estrogens to these cancers. Estrone sulfatase inhibitors may thus prove to be useful for the treatment of these diseases. Several research groups have reported the development of estrone sulfatase inhibitors, and estrone-3-O-sulfamate has been shown to be the most potent sulfatase inhibitor. However, a recent report indicated that estrone may be released during the inactivation of sulfatase by estrone-3-O-sulfamate and rendered the inhibitor to be estrogenic. Therefore, there is a need for a potent non-steroidal sulfatase inhibitor that is metabolically stable, more selective, and lacking estrogenic activity. We developed a series of (p-O-sulfamoyl)-N-alkanoyl tyramines, and they proved to be potent estrone sulfatase inhibitors. Using human placental microsome as the enzyme source, the best inhibitor in this series, compound 18, has an IC50 of 55.8 nM. Another potent inhibitor in this series, compound 17, exhibited time-dependent inactivation of sulfatase when incubated at various concentrations (0.2-1.0 microM) of the inhibitor. Estrone sulfate partially blocked the inactivation of the enzyme by the compound, indicating that the compound inactivated sulfatase at the active site. The irreversible nature of the enzyme-inhibitor interaction was supported by irreversibility studies. Thus, (p-O-sulfamoyl)-N-alkanoyl tyramines represent a new series of non-steroidal estrone sulfatase inhibitor.

Inhibition of placental estrone sulfatase activity and MCF-7 breast cancer cell proliferation by estrone-3-amino derivatives

Estrogen levels in breast tumors of post-menopausal women are as much as 10 times higher than in plasma, presumably due to in situ formation of estrogen. Several lines of evidence indicate that the major source of estrogen in breast cancer cells may be from conversion of estrone sulfate to estrone by the enzyme estrone sulfatase. Inhibitors of estrone sulfatase may thus be potential agents for the treatment of estrogen-dependent breast cancer. We designed and synthesized a series of estrone-3-amino derivatives as potential estrone sulfatase inhibitors. We tested the inhibitory potential of these compounds using human placental microsomes, which contain a substantial amount of estrone sulfatase activity. Several compounds in the series significantly inhibited estrone sulfatase activity of the human placental microsomes when present at 10 microM. The IC50 for the estrone-3-amino compounds ranged from 8.7 to 14.6 microM. We next tested the ability of the estrone-3-amino derivatives to inhibit growth of the estrogen-dependent MCF-7 breast cancer cell line. MCF-7 cells showed substantial proliferation in the presence of 100 nM estrone sulfate in estrogen-free media, indicating that the cells were capable of converting estrone sulfate into estrone. The proliferative effect of estrone sulfate (1 microM) was significantly blocked by the estrone-3-amino derivatives at 10 microM. The magnitude of MCF-7 cell inhibition resulting from treatment with the estrone-3 amino compounds was similar to or exceeded that of Danazol, but was less than the level resulting from treatment with estrone sulfamate. Using data from all of the compounds tested, inhibition of MCF-7 cell proliferation was positively correlated with inhibition of placental estrone sulfatase activity, suggesting that the reduction in cell growth was attributable to the blockade of sulfatase activity. In support of this, there was no relationship between inhibition of estrone sulfatase activity and inhibition of cell growth when the estrogen-independent cell line MDA-MB-231 was used. Our results indicate the possible utility of estrone-3-amino derivatives for inhibition of estrone sulfatase activity. Further, our data support the concept that estrone sulfatase inhibitors may be useful as therapeutic agents for estrogen-dependent breast cancers.

Neutrophil attractant protein-1 interleukin 8 and its autoantibodies in IgA nephropathy

Human neutrophil attractant protein-1/interleukin 8 (IL-8) has been shown to activate neutrophils to degranulate in vitro and to be a potent chemotactic agonist for neutrophils and lymphocytes in vitro and in vivo. There is accumulating evidence that neutrophils are involved in inflammatory injury in IgA nephropathy (IgAN). We studied the serum levels of IL-8 and its autoantibodies of the IgA or IgG class in 36 patients with IgAN in comparison with 31 healthy controls and 26 patients with other primary glomerulonephritides (CGN). Interleukin 8 was more frequently detected in sera of patients with IgAN and their serum levels were significantly higher than those of healthy controls. The free IL-8 autoantibodies of the IgA, but not IgG class, were more frequently detected in patients with IgAN and their serum levels were significantly elevated compared with both groups of controls. The complexed IL-8 autoantibodies of either class were not different among the three groups of subjects. Again the ratio of free to complexed IL-8 autoantibodies of the IgA class was raised in patients with IgAN. Histologic examination revealed increased polymorphs and monocyte/macrophage infiltration in IgAN compared with other glomerulonephritides. When the serum levels of IL-8 and IL-8 autoantibodies were compared between IgAN patients with milder pathology and those with more severe pathology, the latter group had significantly higher serum levels of free and complexed IL-8 autoantibodies of the IgA class. These observations suggest a possible role for IL-8 and its autoantibodies of the IgA class in the inflammatory process of IgAN. These autoantibodies may provide a clinically useful marker for the diagnosis of disease severity.

Transforming growth factor-beta mRNA expression in CD4+ T cells from patients with primary glomerulonephritides

Immunoreactivity to transforming growth factor-beta (TGF-beta) was detected in glomerular cells from patients with chronic glomerulonephritis, yet it remains uncertain whether the glomerular TGF-beta deposits reflect TGF-beta produced by the glomerular cells alone or from additional extrarenal origin. We examined the TGF-beta messanger RNA (mRNA) expression in circulating CD4+ T cells from 45 patients with different primary glomerulonephritides. By semiquantitative polymerase chain reaction, the TGF-beta mRNA expression was significantly raised in histopathologic entities characterized by increased mesangial proliferation or segmental sclerosis but not in histopathologic entities with little mesangial proliferation or sclerosis. These findings suggest that, other than TGF-beta produced de novo, TGF-beta from systemic source can also contribute to mesangial proliferation by binding to the glomerular cells after being filtered by the glomeruli. Increased TGF-beta gene expression in CD4+ T cells in these patients may potentially enhance glomerular injury.

Serologic study of immunoglobulin A-fibronectin aggregates in immunoglobulin A nephropathy

The immunoglobulin A (IgA)-fibronectin aggregates, detected by enzyme-linked immunosorbent assay using either antifibronectin or collagen I as binding protein, were previously found to be raised in the circulation of patients with IgA nephropathy (IgAN). It has been suggested that IgA-fibronectin aggregates are involved in the pathogenesis and that the plasma IgA-fibronectin level may even be of diagnostic value in IgAN. Nevertheless, a recent report has questioned the specificity of these assays as plasma IgA may interact with immobilized IgG and these assays detect not only IgA-fibronectin, but also total plasma IgA. These doubts render the interpretation of raised IgA-fibronectin aggregates in IgAN impossible. We isolated total IgA, in plasma by jacalin-agarose. Monomeric and polymeric IgA1 were distinctly separated by fast protein liquid chromatography. When the fast protein liquid chromatography fractions were analyzed for IgA-fibronectin using the antifibronectin capture assay, increased optical density values were predominantly observed in polymeric IgA but not in monomeric IgA. Similar findings were found when the fast protein liquid chromatography fractions were studied using a novel gelatin-anti-IgA assay that avoided nonspecific interaction between plasma IgA and immobilized IgG used as the capture antibody in antifibronectin capture assay. Using our gelatin-anti-IgA assay, we failed to demonstrate a diagnostic increase in IgA-fibronectin aggregates in polymeric IgA from patients with IgAN compared with controls. Our finding of circulating IgA-fibronectin aggregates in patients with IgAN comparable to those of healthy controls did not support the notion that these aggregates may have a pathogenetic role or diagnostic value in IgAN.

Anti-DNA autoantibodies stimulate the release of interleukin-1 and interleukin-6 from endothelial cells

The pathogenetic mechanism of vasculitis in systemic lupus erythematosus (SLE) remains a subject of debate. Evidence for a direct pathogenetic role of anti-double-stranded DNA antibodies (anti-dsDNA) is not strong. Supernatant concentrations of interleukin-1 beta and interleukin-6, and mRNAs encoding for interleukin-1 alpha and interleukin-1 receptor-1 were determined in cultured human umbilical vein endothelial cells (HUVEC), incubated with control IgG (n = 18), anti-dsDNA (n = 18), or IgG from the same lupus patient depleted of anti-dsDNA by affinity chromatography (anti-dsDNA-dep-IgG). Compared with control IgG, there was a significant increase of supernatant interleukin-1 beta and interleukin-1 alpha mRNA in endothelial cells incubated with anti-dsDNA. The supernatant interleukin-1 beta and interleukin-6, and mRNAs encoding for interleukin-1 alpha and interleukin-1 receptor-1, were significantly elevated in endothelial cells incubated with anti-dsDNA, compared with those incubated with anti-dsDNA-dep-IgG. Pretreating HUVEC with native DNA before incubating with anti-dsDNA did not result in an additive effect. These in vitro studies suggest that anti-dsDNA plays an important pathogenetic role in inducing inflammatory injury of vascular endothelium in SLE.

Increased binding of polymeric lambda-IgA to cultured human mesangial cells in IgA nephropathy

IgA nephropathy (IgAN) is characterized by raised plasma lambda-IgA1 and mesangial polymeric lambda-IgA1 deposits. It remains uncertain whether the predominant glomerular lambda-IgA1 deposits represent a selective uptake of polymeric IgA or a non-specific uptake due to elevated circulating lambda-IgA1 levels in response to an unidentified antigen. In this study, we explored whether there is an increased binding of monomeric IgA1 (mIgA1) or polymeric IgA1 (pIgA1) from patients with IgAN to cultured human mesangial cells (HMC). Total IgA1 in plasma from patients or healthy controls was isolated by jacalin-agarose column as jacalin-bound proteins (JBP). Monomeric IgA1 and pIgA1 were distinctly separated by FPLC. HMC were incubated with IgA preparations and IgA bound to HMC was determined by flow cytometry analysis using standard curves constructed by known concentrations of kappa-IgA1 or lambda-IgA1. In order to avoid any increased binding of IgA to HMC due to elevated kappa- or lambda-IgA concentrations in JBP samples from patients, JBP samples from patients or controls were appropriately diluted to achieve comparable levels of total IgA1. No differences in the total mIgA1 or pIgA1 concentration, percentage of mIgA1 or pIgA1, or the kappa/lambda ratio of mIgA1 or pIgA1 were found between adjusted JBP samples from patients or healthy controls. We found a sharp rise in percentage of pIgA1 among IgA1 bound to HMC (70%), despite the fact that only 3% of the IgA1 in the adjusted JBP samples were polymeric, suggesting that pIgA1 had a higher affinity to HMC than mIgA1. Furthermore, the kappa/lambda ratios of pIgA1 bound to HMC were significantly lower than the kappa/lambda ratios of pIgA1 in adjusted JBP only with IgAN patients but not healthy controls (P = 0.0026). Our data suggest a preferential mesangial binding of polymeric lambda-IgA1 from patients with IgAN. These polymeric lambda-IgA immune complexes are likely to be "pathogenic" and are important in the pathogenesis of IgAN.

Acute renal failure induced by angiotensin converting enzyme inhibitor in a patient with polyarteritis nodosa

We report a patient who presented with malignant hypertension and renal failure. He was treated with lisinopril, spironolactone, and nifedipine retard for blood pressure control. Subsequent renal function showed further deterioration, but it then improved after withdrawal of the angiotensin converting enzyme inhibitor (ACE I). The diagnosis of classical polyarteritis nodosa was established with aneurysmal dilatation demonstrable in the renal vasculature. His renal impairment improved further following immunosuppressive therapy and the disease has remained inactive 4 years after first presentation. This is the first reported case of acute renal failure associated with the use of ACE I in polyarteritis nodosa.

Alport's syndrome in monozygotic twins

Identical twins presented at the same time with renal failure. They also recalled a simultaneous history of "nephritis" as early as the age of 6 years. Renal biopsies revealed variably thickened glomerular basement membranes with the lamellation and splitting characteristic of Alport's syndrome. Bilateral sensorineural deafness was demonstrated in both twins on audiometric testing. A positive family history in the mother and one elder sister confirmed the diagnosis of Alport's syndrome. This is the first reported case of Alport's syndrome occurring in monozygotic twins.

Effect of renal transplantation on pulmonary function in patients with end-stage renal failure

Ten patients with end-stage renal failure on maintenance dialysis underwent serial lung function tests before and at monthly intervals after renal transplantation. Mean values of forced expiratory volume within 1 s, forced vital capacity, and total lung capacity were within the normal range before and up to 6, months after transplantation. The mean value of residual volume (RV) was above the normal range during all periods measured (157.8 +/- 21.5% predicted before transplantation and 121.2 +/- 17.0% predicted at 6 months after transplantation). No statistically significant changes in lung volumes were detected over a course of 6 months, but there was a trend for a reduction in RV after transplantation. The single-breath diffusion capacity for carbon monoxide (DLCO) was in the high-normal range before transplantation (115.7 +/- 9.5% predicted). It remained high at 1 month after transplantation (124.5 +/- 12.2% predicted), but it gradually came down to the normal range from the 2nd month onwards. At 6 months after transplantation the mean DLCO was 83.8 +/- 7.3% of predicted which was significantly (p < 0.0001) lower than the value before transplantation. We conclude that raised DLCO and RV values occurred in patients with end-stage renal failure on maintenance dialysis which were most likely the result of pulmonary vascular congestion, and these abnormalities tend to improve after renal transplantation.

Paecilomyces varioti peritonitis in patients on continuous ambulatory peritoneal dialysis

Paecilomyces varioti infection is a rare cause of peritonitis in patients on continuous ambulatory peritoneal dialysis (CAPD). We report two patients who developed P varioti peritonitis complicating CAPD. The clinical features and microbiological data of seven other previously reported cases are reviewed. Approximately half of the patients had received multiple antibiotics before the onset of the peritonitis because of either bacterial peritonitis or exit site infection. There was no particular pattern of peritoneal dialysate cell count, which was characteristic in this fungal peritonitis. Although all patients survived, morbidity was high. All patients required antifungal chemotherapy and removal of peritoneal catheter for eradication of the organism. Amphotericin B was effective in most cases. Patients of all previously reported cases did not go back to peritoneal dialysis after removal of peritoneal catheters. A combination of oral flucytosine and itraconazole was successful in treating our two patients. Although we managed to resume CAPD in our two patients with good functional outcome, abscesses and adhesions were major problems rendering most patients from other series failing to return to CAPD after recovery.

Dermatofibrosarcoma protuberans in a renal transplant patient

Dermatofibrosarcoma protuberans in an unusual soft tissue tumour with a propensity for local recurrence and rarely metastatic spread. Given its indolent course it may be mistaken for atypical scarring or a keloid growth. Early diagnosis and prompt wide local resection of this entity are required in order to prevent a local recurrence. We report a patient who developed locally invasive dermatofibrosarcoma protuberans 4 years after a successful renal transplantation. Although other forms of sarcoma have been reported as a complication of organ transplantation and immunosuppression, this pathology has, so far, not been reported in a transplant recipient.

Effect of fluvastatin on lipoprotein profiles in treating renal transplant recipients with dyslipoproteinemia

A single, blinded placebo-drug trial was conducted to study the efficacy and safety of fluvastatin, a new 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitor, in treating dyslipoproteinemia in 16 renal transplant recipients who had been on an immunosuppressive regimen that included cyclosporine (CsA). They were studied for 32 consecutive weeks, with 4 weeks of baseline treatment, 4 weeks of placebo, 12 weeks of treatment with fluvastatin 20 mg daily, and 12 weeks of fluvastatin 40 mg daily. Blood samples were obtained every 4 weeks for measurement of the lipoprotein profiles, which included total cholesterol (TC), triglyceride, low density lipoprotein (LDL)-, high density lipoprotein (HDL)-, HDL2-, HDL3- and very low density lipoprotein-cholesterol (C), apolipoprotein (Apo) A-1, Apo B, and lipoprotein(a). Fifteen patients completed the trial. After 12 weeks of treatment, fluvastatin 20 mg significantly reduced TC by 13.4% (from 6.7 +/- 0.5 [mean +/- SEM] to 5.8 +/- 0.2 mmol/L), LDL-C by 22% (from 4.1 +/- 0.3 to 3.2 +/- 0.2 mmol/L), and Apo B by 13.2% (from 159.6 +/- 8.8 to 138.6 +/- 9.2 mg/dl) (P < 0.005). The subsequent 12-week treatment of fluvastatin 40 mg significantly reduced TC by 16.4% to 5.6 +/- 0.3 mmol/L, LDL-C by 29.3% to 2.9 +/- 0.2 mmol/L, and Apo B by 18.2% to 130.6 +/- 5.5 mg/dl (P < 0.00005). There was no significant change in levels of other lipoproteins, including lipoprotein (a). There were no significant changes in the whole blood trough CsA concentrations, renal and liver function tests, and serum creatine phosphokinase level during treatment when compared with baseline and placebo. No patient complained of myalgia or failed to complete the study due to side effects of the drug. Fluvastatin appears to be safe and effective in treating dyslipoproteinemia in renal transplant recipients who are maintained on CsA.

Reversal of scopolamine induced amnesia in rats by the steroid sulfatase inhibitor estrone-3-O-sulfamate

The intent of the study was to determine whether altering the metabolism of neurosteroids via blockade of the enzyme, steroid sulfatase, could enhance retention test performance in rats. The steroid sulfatase inhibitor estrone-3-O-sulfamate (EMATE) was administered alone and in combination with the neurosteroid dehydroepiandrosterone sulfate (DHEAS) to rats which were then tested for the reversal of scopolamine induced amnesia. EMATE enhanced the reversal of amnesia by DHEAS as measured by a passive avoidance test. When administered without DHEAS, as a single acute dose, EMATE had no effect. When administered without DHEAS over 10 consecutive days, however, EMATE significantly improved retention. These results suggest that steroid sulfatase inhibition can potentiate the memory enhancing properties of DHEAS. The study also suggests that increasing the levels of endogenous sulfated neurosteroids via the inhibition of steroid sulfatase activity may enhance learning and/or memory function.

Molecular genetics of major histocompatibility complex class II genes in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common malignant tumor of the liver with a possible genetic predisposition. We have studied the HLA-DQ and -DR regions of 57 unrelated HCC patients of southern Chinese origin using molecular DNA techniques and compared them with 104 normal controls. Seventy-six hepatitis B carriers (HBsAg) were also studied. Restriction fragment length polymorphism (RFLP) was used to genotype the MHC class II DR beta, DQ alpha and DQ beta loci of the subjects. Polymerase chain reaction (PCR) using sequence primer for DQ beta genes was also performed. No significant difference was found in the HLA-DQ and -DR loci between HCC patients and normal controls, HCC patients and HBsAg carriers, or HBsAg carriers and normal controls respectively. Forty-one HCC patients were HBsAg positive, and no difference was found in the HLA-DQ and -DR genotype between this group of patients compared with the group of normal controls or HBsAg carriers. Thirty-six HCC patients had elevated alpha-fetoprotein levels, and 15 HCC patients had normal levels. No difference in the HLA-DQ and -DR loci was detected between these two groups and the controls. The results suggest that HLA-DQ and -DR genotypes are not associated with hepatocellular carcinoma in southern Chinese.

Microscopic polyarteritis has a poor prognosis in Chinese

OBJECTIVE

To analyze retrospectively the clinical course and outcome of 10 consecutive Chinese patients with microscopic polyarteritis (MPA) admitted to our hospital over a period of 3 years.

METHODS

Ten patients with MPA who presented 1990-93 were studied. Their serum antineutrophil cytoplasmic autoantibody levels were assayed.

RESULTS

The male to female ratio was 1:1 and the mean age was 61 years. Eight patients (80%) had renal impairment on presentation and 5 of them (50%) were dialysis dependent. Seven patients (70%), during their clinical course, had pulmonary hemorrhage. Six patients (60%) had hypoxic lung disease requiring ventilatory support. All 10 patients were pANCA positive; 8 patients were tested for antimyeloperoxidase antibody and were all positive. Seven patients were treated with immunosuppressants consisting of steroid and cyclophosphamide with additional plasma exchange. Nine patients died after a mean survival of 9 months (range 1-33); causes of death were respiratory failure (5), infection (2), uremia (one), and stroke (one). The ANCA level reflected the disease activity of the vasculitis.

CONCLUSION

MPA in Chinese patients appeared to be a more severe disease with a poor prognosis. This may be related to the older age group, and the more frequent and severe pulmonary and renal manifestations of MPA in these patients.

No association between HLA-DQ and -DR genotypes with nasopharyngeal carcinoma in southern Chinese

The pathogenesis of nasopharyngeal carcinoma (NPC) is multifactorial. Associations have been reported between HLA and NPC. We studied the HLA-DR and -DQ regions on the molecular level in 136 persons (51 NPC patients and 85 healthy controls) from southern China, a particularly high-prevalence area for NPC. Restriction fragment-length polymorphism (RFLP) was used to genotype the MHC class II DR beta, DQ alpha, and DQ beta regions of the subjects. Polymerase chain reaction (PCR) using sequence-specific primer (SSP) for DQ beta genes was also performed. By RFLP, no significant difference was observed with respect to DRB, DQA, and DQB genes. By PCR SSP typing, we confirmed that there was no significant difference between NPC patients and controls with respect to DQ beta alleles. Our study suggests that HLA-DQ and -DR genes are not associated with NPC in southern Chinese and there may be other gene loci that predispose them to have such a high prevalence of the disease.

Lack of association between HLA-DQ and -DR genotypes and asthma in southern Chinese patients

Asthma is an inflammatory disease with a strong genetic predisposition. We have studied a group of unrelated asthmatic patients of southern Chinese origin on their HLA-DR and -DQ regions using molecular techniques and compared them with 104 healthy controls of the same ethnic origin. Restriction fragment length polymorphism (RFLP) was used to genotype the MHC class II DR beta, DQ alpha and DQ beta loci of the subjects. Polymerase chain reaction (PCR) using sequence specific primer (SSP) for DQ beta genes was also performed. No significant difference was found in the HLA-DQ and -DR loci between the patients and the controls. All patients had their serum IgE antibody levels measured, bronchial reactivity assessed by histamine broncho-provocation and cutaneous reactivity to common allergens determined by skin-prick tests to Dermatophagoides pteronyssinus, Dermatophagoides farinae, mixed grass pollens, Aspergillus fumigatus, cat fur and dog dander and they were classified respectively. The HLA-DR and -DQ genotypes of these subgroups of patients were compared. There was no significant difference among these subgroups of patients according to their serum IgE levels, the degree of bronchial reactivity and whether they were positive for the skin tests for the various allergens respectively. The results suggest that HLA-DQ and -DR genotypes are not associated with asthma in southern Chinese people.

The interaction of fluvastatin and cyclosporin A in renal transplant patients

A possible interaction between fluvastatin, a new HMG CoA reductase inhibitor, and cyclosporin A (CsA) was studied in 16 stable renal transplant patients with dyslipoproteinemia despite dietary control. They entered a 12-week study period: 4-week baseline, 4-week placebo and 4-week fluvastatin treatment (20 mg daily). Weekly trough whole blood CsA concentrations were measured by monoclonal antibody immunoassay. Serial renal and liver function tests and creatine phosphokinase (CPK) were monitored. The mean trough levels of CsA during fluvastatin treatment were 115.6 micrograms/l compared with 114.3 micrograms/l and 113.3 micrograms/l in the baseline and placebo period, respectively. Apart from a small decrease in serum albumin level (from a mean of 38.6 g/l to 37.9 g/l), there were no significant changes in renal and liver functions or CPK levels. No adverse effects were reported. Fluvastatin (20 mg daily) may be used safely without extra monitoring of blood CsA concentrations in renal transplant patients.

Estrone sulfate analogs as estrone sulfatase inhibitors

The high serum concentration of estrone sulfate and the presence of estrone sulfatase in breast tumors constitute an important mechanism of local synthesis of estrogens in the tissue. Thus, inhibitors of estrone sulfatase may be effective in the treatment of estrogen-dependent breast cancer. In this study, we synthesized several isostructural analogs of estrone sulfate (estrone-3-methylsulfonate, estrone phosphate, 3-desoxyestradiol-3-methylenesulfonate, and 3-desoxyestrone-3-methylenesulfonate) and tested them on human placental sterylsulfatase. The results were (i) The Ki of 3-desoxyestrone-3-methylenesulfonate 12 and 3-desoxyestradiol-3-methylenesulfonate 7 are more than 100-fold higher than the Ki or KM values for estrone sulfate, (ii) As compared to estrone sulfate, the Ki value for estrone-3-methylsulfonate 2 is about 30-fold higher, while estrone phosphate 3 is bound by the sulfatase with roughly the same affinity as estrone sulfate. The results shed some light on the electronical and sterical requirements for high affinity binding to the enzyme.