Structure–activity-relationship studies of conformationally restricted analogs of combretastatin A-4 derived from SU5416

A series of combretastatin A-4 analogs derived from the ATP competitive, VEGF receptor tyrosine kinase inhibitor, SU5416 were synthesized. The cytotoxic effects of the analogs were evaluated against PC-3 and MDA-MB-231 cancer cell lines, as well as their abilities to inhibit tubulin polymerization. Results are compared to those of compound 1, our lead compound previously reported.

A thalidomide analogue with in vitro antiproliferative, antimitotic, and microtubule-stabilizing activities

We discovered a thalidomide analogue [5-hydroxy-(2,6-diisopropylphenyl)-1H-isoindole-1,3-dione (5HPP-33)] with antiproliferative activity against nine cancer cell lines in vitro. Flow cytometric analyses showed that the compound caused G2-M arrest, which occurred mainly at the mitotic phase. In addition, immunofluorescence microscopy and in vitro tubulin polymerization studies showed that 5HPP-33 has antimicrotubule activity with a paclitaxel-like mode of action. It is effective against four different paclitaxel-resistant cell lines. Thus, 5HPP-33 represents a potential antitumor agent.

Conformationally restricted analogs of Combretastatin A-4 derived from SU5416

A series of compounds originally derived from the vascular endothelial growth factor receptor tyrosine kinase inhibitor, SU5416, was synthesized and evaluated. The most potent compound in this series, compound 7, structurally resembles the potent anti-microtubule agent Combretastatin A-4, inhibited tubulin polymerization, and showed potent growth inhibitory activities on both prostate and breast cancer lines with IC(50) values in low to subnanomolar range.

Translational studies on aromatase, cyclooxygenases, and enzyme inhibitors in breast cancer

Aromatase expression and enzyme activity in breast cancer patients is greater in or near the tumor tissue compared with the normal breast tissue. Regulation of aromatase expression in human tissues is quite complex, involving alternative promoter sites that provide tissue-specific control. Previous studies in our laboratories suggested a strong association between aromatase (CYP19) gene expression and the expression of cyclooxygenase (COX) genes. Our hypothesis is that higher levels of COX expression result in higher levels of prostaglandin E2 (PGE2), which in turn increases CYP19 expression through increases in intracellular cyclic AMP levels. This biochemical mechanism may explain the beneficial effects of non-steroidal anti-inflammatory drugs (NSAIDs) on reducing the risks of breast cancer. The effects of NSAIDs (ibuprofen, piroxicam, and indomethacin), a COX-1 selective inhibitor (SC-560), and COX-2 selective inhibitors (celecoxib, niflumic acid, nimesulide, NS-398, and SC-58125) on aromatase activity and CYP19 expression were investigated in breast cancer cell culture systems. Dose-dependent decreases in aromatase activity were observed following treatment with an NSAID or COX inhibitor, with the most effective agents being COX selective inhibitors. Real time PCR analysis of aromatase gene expression showed a significant decrease in mRNA levels in treated cells when compared to vehicle control. These results suggest that the effect of COX inhibitors on aromatase occurs at the transcriptional level. To further probe these interactions, short interfering RNAs (siRNA) were designed against either human CYP19 mRNA or human COX-2 mRNA. Treatment of breast cancer cells with aromatase siRNAs suppressed CYP19 mRNA and aromatase enzyme activity. Finally, treatment with COX-2 siRNAs downregulated the expression of COX-2 mRNA; furthermore, the siCOX-2-mediated suppression of COX-2 also resulted in suppression of aromatase mRNA. In summary, pharmacological regulation of aromatase and cyclooxygenases can act locally in an autocrine fashion to decrease the biosynthesis of estrogen and may provide additional therapy options for patients with hormone-dependent breast cancer.

Neurosteroid paradoxical enhancement of paired-pulse inhibition through paired-pulse facilitation of inhibitory circuits in dentate granule cells

Neurosteroids are produced in the brain independently of peripheral endocrine glands to act locally in the nervous system. They exert potent promnesic effects and play significant roles in mental health-related disorders. In part, neurosteroids act by affecting ligand-gated ion channels and metabotropic receptors through rapid non-genomic processes. We have previously demonstrated that neurosteroids also affect synaptic transmission presynaptically in the CA1 region of the hippocampus. Here we describe the effects of the most abundant neurosteroid in the rodent brain, pregnenolone sulfate (PregS), on signal processing in the dentate subfield of the hippocampus. We show that PregS acts presynaptically at low concentrations (300 nM) to enhance paired-pulse facilitation (PPF) in perforant pathway terminals on dentate granule cells. Similar effects were found with two steroid sulfatase inhibitors demonstrating a potential contribution of endogenous steroids to dentate synaptic plasticity. This enhanced presynaptic facilitation paradoxically increases paired-pulse inhibition (PPI) at short interpulse intervals. Based on these data, a model of dentate gyrus circuit interactions is proposed for the presynaptic action of PregS on the filtering dynamics of the dentate subfield at frequencies similar to those of the endogenous signals from the entorhinal cortex. These modeling studies are consistent with experimental measurements demonstrating positive modulation by PregS at low frequencies and negative modulation at high frequencies. These studies show an important role for the presynaptic action of neurosteroids in modulating input signals to the hippocampus.

The actions of a charged melatonin receptor ligand, TMEPI, and an irreversible MT2 receptor agonist, BMNEP, on mouse hippocampal evoked potentials in vitro

We have previously determined that melatonin modulates hippocampal synaptic transmission in a biphasic way: an initial depression was followed by a recovery/amplification phase. Here we describe the influence of two novel melatonin receptor ligands, BMNEP (N-bromoacetyl-2-iodo-5-methoxytryptamine) and TMPEI (N-[2-(2-Trimethylammoniumethyleneoxy-7-methoxy)ethyl]propionamide iodide), on the population spike (PS) and excitatory postsynaptic potentials (EPSP) recorded from mouse hippocampal slices. BMNEP, which specifically alkylates and constitutively activates the MT2 melatonin receptor, mimicked the first phase of melatonin's action by irreversibly depressing both the PS and EPSP. TMPEI, a charged ligand of plasma membrane melatonin receptors, amplified those potentials in a manner similar to the effect of melatonin observed during the second, recovery phase. Melatonin had no influence on the potentials amplified by the action of TMPEI. Our results suggest that the biphasic, receptor-dependent action of melatonin and its analogs modulates the efficiency of the hippocampal glutamergic synapse and is most likely mediated through two different, sequentially occurring mechanisms.

Asymptomatic isolated microscopic haematuria: long-term follow-up

BACKGROUND

Evidence to support current diagnostic and management approaches to asymptomatic haematuria is lacking and based on short-term clinical observation.

AIM

To ascertain the natural history and long-term outcome of asymptomatic and isolated haematuria, and to determine the clinical correlates of adverse renal events.

DESIGN

Prospective observational referral-based study.

METHODS

We evaluated 90 consecutive patients with isolated microscopic haematuria, first seen between 1985 and 1996 at an out-patient nephrology clinic. We defined adverse renal events as the development of proteinuria (> 0.5 g/24 h) on two consecutive occasions, development of hypertension, or impaired renal function characterized by glomerular filtration rate (GFR) of <60 ml/min/1.73 m(2) for 3 months or more.

RESULTS

There were 24 males and 66 females, median follow-up 5.2 years (total 442 patient-years). Mean age at presentation was 39 +/- 13 years. Fifteen (17%) had complete resolution of microscopic haematuria. One (1%) had transitional cell carcinoma of urinary bladder 20 months after initial presentation. Twelve (13%) developed hypertension, and 10 (11%) proteinuria. Only one developed chronic renal failure, 2.3 years after initial presentation. Altogether, 16 (19%) developed at least one adverse event, after a mean 42 months. Neither history of renal biopsy nor histological diagnosis of glomerular disease was predictive of renal events. Three independent variables were predictive of adverse renal events: baseline proteinuria (RR per 0.1 g/day 2.04; 95%CI 1.13-3.68; p = 0.018); MDRD-estimated GFR at presentation (RR per 10 ml/min/1.73 m(2) decrement 2.01; 95%CI 1.09-3.71; p = 0.025); and baseline serum urate (RR per 100 micromol/l 1.02; 95%CI 1.01-1.03; p = 0.009).

DISCUSSION

Asymptomatic microscopic haematuria can lead to adverse renal events, and warrants nephrologist evaluation and regular follow-up. Its isolated microscopic haematuria is closely related to early hints of chronic kidney disease, such as low-grade proteinuria and renal insufficiency, as well as hyperuricaemia.

Fetal alcohol exposure alters neurosteroid levels in the developing rat brain

Neurosteroids are modulators of neuronal function that may play important roles in brain maturation. We determined whether chronic prenatal ethanol exposure altered neurosteroid levels in the developing brain. Rat dams were exposed to: (i) a 5% ethanol-containing liquid diet that produces peak maternal blood alcohol levels near the legal intoxication limit (approximately 0.08 g/dL); (ii) an isocaloric liquid diet containing maltose-dextrin instead of ethanol with pair-feeding; (iii) rat chow ad libitum. Neurosteroid levels were assessed in offspring brains using radioimmunoassay or gas chromatography-mass spectrometry techniques. A prenatal ethanol exposure-induced increase in pregnenolone sulfate levels, but not dehydroepiandrosterone sulfate levels, was evident at the earliest time point studied (embryonic day 14). This effect lasted until post-natal day 5. Levels of other neurosteroids were assessed at embryonic day 20; pregnenolone levels, but not allopregnanolone levels, were elevated. Pregnenolone sulfate levels were not altered in the maternal brain. Neither pregnenolone nor pregnenolone sulfate levels were significantly altered in the fetal liver, placenta and maternal blood, indicating that the effect of ethanol is not secondary to accumulation of peripherally-produced steroids. Fetal ethanol exposure has been shown to decrease both cellular and behavioral responsiveness to neurosteroids, and our findings provide a plausible explanation for this effect.

Structure-activity relationships studies of the anti-angiogenic activities of linomide

The synthesis and anti-angiogenic activities of linomide and its analogues are reported. Three of the analogues are 3.3-69 times more potent than linomide at inhibiting blood vessel formation in the CAM angiogenesis assay. These compounds possessed considerable anti-proliferative activity against isolated HUVEC cells with no activity against epithelial-derived prostate tumor cells.

Inhibition of steryl sulfatase activity in LNCaP human prostate cancer cells

The enzyme steryl sulfatase may help support the growth of hormone-dependent tumors, including prostate cancers, by facilitating the conversion of circulating precursor steroids to active hormones. We sought to determine the presence of steryl sulfatase activity in the androgen-dependent human prostate cancer cell line LNCaP, and to determine if this activity was inhibited by known steryl sulfatase inhibitors. Intact LNCaP cultures had steryl sulfatase activity, as determined by conversion of [3H]estrone sulfate (E(1)S) to unconjugated steroids. The level of steryl sulfatase activity was relatively low (4.6 pmol/18 h/million cells) compared to MDA-MB-231 breast cancer cells (284.0 pmol/18 h/million cells). The observed activity in both cell lines was blocked by addition of 1 microM estrone sulfamate (EMATE), an active-site-directed, steroidal inhibitor of steryl sulfatase. Steryl sulfatase activity was also inhibited by Danazol, and by (p-O-sulfamoyl)-tetradecanoyl tyramine (C2-14), a non-steroidal inhibitor. Microsomes prepared from LNCaP cultures also showed steryl sulfatase activity, as determined by hydrolysis of [3H]E(1)S and [3H]dehydroepiandrosterone sulfate (DHEAS) to unconjugated forms. LNCaP and MDA-MB-231 microsomes both hydrolyzed E(1)S about two times faster than DHEAS. Hydrolysis of E(1)S in LNCaP and MDA-MB-231 microsomes was blocked by steryl sulfatase inhibitors with the following relative potencies: EMATE>C2-14>Danazol. These data demonstrate that LNCaP prostate cancer cells contain a steryl sulfatase with properties similar to that found in human breast cancer cells, and that the activity of this enzyme can be blocked by known steryl sulfatase inhibitors. Steryl sulfatase inhibitors may be useful as an adjuvant to androgen deprivation therapy for prostate cancer.

The cost barrier to peritoneal dialysis in the developing world--an Asian perspective

Countries in Asia vary significantly in culture and socioeconomic status. Dialysis costs and reimbursement structures are significant factors in decisions about the rates and modalities of renal replacement therapy. From our survey of Asian nephrologists conducted in 2001, a number of observations can be made. In many developing countries, the annual cost of continuous ambulatory peritoneal dialysis (CAPD) is greater than the per-capita gross national income (GNI). The median cost of a 2-L bag of peritoneal dialysis (PD) fluid is around US$5. The absolute cost of PD fluid among countries with significant differences in per-capita GNI actually varies very little. Thus, most renal failure patients can be expected to have problems accessing PD therapy in developing countries in Asia. In countries with unequal reimbursement policies for PD versus hemodialysis, a lack of incentive to prescribe PD also exists. Automated PD is nearly non existent in many developing countries in Asia. Some possible ways to reduce the cost barriers to PD in those countries include individual governments providing more public funding for treating dialysis patients; dialysate-producing companies reducing the cost of their products; physicians using appropriately smaller exchange volumes (3 x 2 L) in some Asian patients with smaller body sizes and with residual renal function; and reducing the complication rate for PD (for example, peritonitis) thereby reducing the costs required for treatment and hospitalization.

Adequacy targets of peritoneal dialysis in the Asian population

End-stage renal disease affects a large number of patients in Asia. The percentage of patients utilizing PD varies significantly in Asian countries. Continuous ambulatory peritoneal dialysis (CAPD) accounts for about 80% of the dialysis population in Hong Kong. In this review, we address several questions related to adequacy targets in Asians: Are Asians different? Is dialysis adequacy important for Asians? What is the magnitude of the benefit and the optimal dose of dialysis prescription? Is the adequacy target realistic? The current international recommendations, including the Dialysis Outcomes Quality Initiative guidelines, are compared with some of our own data for Asian patients. Our published data on dialysis adequacy, nutrition, residual renal function, and peritoneal membrane transport showed that those factors have a significant impact on the morbidity and mortality of PD patients in Hong Kong. Our results show that solute clearance as measured by Kt/V has a significant impact on the outcome of Asian CAPD patients. Although Chinese PD patients have excellent medium-term patient and technique survival despite an apparently lower Kt/V as compared with the CANUSA standard, that favorable outcome should not prevent nephrologists from providing adequate dialysis to Asian patients. From our own data and analysis, we propose a target Kt/V of 1.9 in Asian CAPD populations. Small-volume dialysis (6 L daily) may be an acceptable compromise in some Asian populations with a smaller body size, especially with residual renal function, given the financial constraints in some developing countries. Dialysis adequacy means more than a Kt/V value; other clinical parameters are equally if not more important. Thus we should also aim at achieving adequate fluid removal and volume homeostasis, blood pressure control, good nutrition, normal acid-base balance, normal mineral metabolism, minimal anemia, and normal lipid metabolism.

Effects of putative hydroxylated thalidomide metabolites on blood vessel density in the chorioallantoic membrane (CAM) assay and on tumor and endothelial cell proliferation

Angiogenesis, in particular anti-angiogenesis, is an area of particular therapeutic interest in cancer treatment. Several anti-angiogenic agents are in the final stages of clinical trials. One of these agents, thalidomide, best known for its teratogenic potential, is showing promise against several tumor types. Thalidomide has been shown previously to require bio-activation to exert its anti-angiogenic effect in isolated blood vessels and endothelial cells. In this work, we confirmed these findings using the in utero chicken embryo chorioallantoic membrane (CAM) system. In particular, the anti-angiogenic effect of thalidomide is significantly enhanced by activation by human but not by rat liver microsomes. We also showed in the CAM assay that hydroxylation of thalidomide at either the 1'- or 5-position retained anti-angiogenic activity whereas its hydroxylation at the 4-position led to an inactive compound. We further demonstrated that thalidomide shows weak anti-proliferative activity against MDA-MB-231 human breast cancer cells in culture. Thalidomide showed slightly more anti-proliferative activity, however, against the SH-SY5Y human neuroblastoma and human umbilical vein endothelial cell (HUVEC) types. Furthermore, incubation of thalidomide with human liver microsomes added no additional anti-proliferative effect in these cell types versus thalidomide given alone. Finally, we report that none of the thalidomide metabolites tested had any anti-proliferative effect against the breast or neuroblastoma cells, but do possess appreciable anti-proliferative activity against the endothelial cells. In summary, this work suggests that hydroxylated thalidomide analogs based on putative metabolites of the drug possess significant anti-angiogenic activity and that exploring further derivatives of these as potential anti-angiogenic agents warrants further merit.

Solid-phase synthesis of thalidomide and its analogues

A novel solid-phase synthesis of thalidomide and its metabolites and analogues is described. The synthetic strategy involves the coupling of hydroxymethyl polystyrene with phthalic anhydride to form the resin-linked acid. The acid is then reacted with primary amines followed by acid or base treatment to form thalidomide and its analogues with either open or closed phthalimide rings. Most of the analogues are synthesized with high yields (40.3-98.1% in three steps) and purities (92.3-98.9%).

Design and synthesis of Pfmrk inhibitors as potential antimalarial agents

The synthesis and inhibitory activities of 10 potential inhibitors of Pfmrk, a Plasmodium falciparum cyclin-dependent protein kinase, are described. The most potent inhibitor is a 3-phenyl-quinolinone compound with an IC(50) value of 18 microM. It is the first compound reported to inhibit Pfmrk at the micro molar range.

Severe bone marrow failure associated with the use of alternating steroid with chlorambucil in lupus membranous nephropathy in Chinese

Severe pancytopenia associated with the use of alternating steroid with chlorambucil regimen was described in six patients with nephrotic syndrome secondary to lupus membranous nephropathy (WHO class V). We believe this is the first report describing the life-threatening degree of marrow toxicity associated with this regimen of alternating steroid with chlorambucil in a Chinese population. Our data suggests that the susceptibility to marrow toxicity with the use of chlorambucil may only be applicable to Chinese patients with underlying systemic lupus erythematosus as a similar degree of toxicity has neither been reported in lupus patients of other ethnic groups nor in non-lupus patients of Chinese origin.

Recurrent IgA nephropathy in renal transplant allografts

Previous reports of renal transplantation for patients with underlying immunoglobulin A (IgA) nephropathy suggested a recurrence rate greater than 50% for transplant IgA nephropathy. Initially regarded as a benign condition, more recent data showed that recurrent transplant IgA nephropathy may be a significant contributor to graft loss. We performed a retrospective analysis in a single center of 48 kidney transplant recipients, all of Chinese origin, with biopsy-proven IgA nephropathy as the cause of end-stage renal failure to determine the recurrence rate of IgA nephropathy in the transplant allograft and subsequent clinical course in Chinese patients. Median duration of follow-up was 52 months (range, 18 to 155 months). Fourteen patients (29%) had biopsy-confirmed recurrent transplant IgA nephropathy after a median of 52 months (interquartile range, 23 to 82 months) posttransplantation. Recurrent transplant IgA nephropathy was associated with greater serum IgA levels (P = 0.01). The presence of HLA-A2 in transplant recipients (P = 0.002) appeared to protect them from developing recurrent IgA nephropathy in the transplant allograft. Twenty-nine percent of patients with recurrent transplant IgA nephropathy had progressive deterioration of graft function. The progressive graft dysfunction (GD) rate was greater in patients with a transplant from a living related donor (LRD; 21%) compared with those with a transplant from a cadaveric or living unrelated donor (URD; 3%; P = 0.062). Although the cumulative graft survival rate was 100% at 5 years for transplants from both LRDs and URDs, the 10-year graft survival rate was only 63% for a graft from an LRD versus 93% for a URD (log-rank test, P = 0.19). A review of other reported series of recurrent transplant IgA nephropathy also showed an apparently greater incidence of GD for a graft from an LRD (28%) compared with a URD (15%). Our data suggest that although recurrent transplant IgA nephropathy is highly prevalent among the Chinese population, the risk for disease recurrence is not particularly increased compared with other ethnic groups. The trend toward a greater risk for GD for living related compared with unrelated allografts in patients with IgA nephropathy needs to be confirmed with further prospective study.

Nonconvulsive status epilepticus in peritoneal dialysis patients

This report describes nonconvulsive status epilepticus (NCSE) in four patients with end-stage renal disease (ESRD) on peritoneal dialysis therapy. All patients presented with acute confusion or stuporous state without clinical motor seizures. Three patients had active systemic infections and were being administered antibiotics. Diagnoses were confirmed in all cases by electroencephalogram (EEG), which showed characteristic diffuse sharp waves and spikes. The EEG appearance improved after anticonvulsant therapy. All patients had satisfactory control of their electrical seizure activity and made varying degrees of mental recovery. To our knowledge, this is the first reported series of NCSE in patients with ESRD on peritoneal dialysis therapy. It shows NCSE as a differential diagnosis for acute confusion. We emphasize the need for nephrologists to consider NCSE as a differential diagnosis for uremic encephalopathy.

Selective internal radiation therapy by yttrium-90 microspheres for hepatocellular carcinoma after renal transplantation

We report a HBsAg-positive patient who developed hepatocellular carcinoma (HCC) 7 years after cadaveric kidney transplantation. The tumor was unresectable because of coexisting cirrhosis. Selective internal radiation (SIR) therapy, a novel therapy with the technique recently perfected, was used. Yttrium-90 microspheres were given via an angiographic catheter under fluoroscopy guidance. Serum alpha-fetal protein (AFP) was normalized within 2 wk. A follow-up abdominal CT scan revealed significant necrosis of the tumor and compensatory hypertrophy of non-diseased liver. The treatment was well tolerated except for transient liver function deterioration. The patient enjoyed 15 months of symptom-free survival before she died of liver failure. Practical aspects and potential applications of SIR therapy in this group of patients are discussed.

Rapid recurrence of ANCA-negative pauci-immune vasculitis after cadaveric renal transplantation

We report a patient with renal failure secondary to antineutrophil cytoplasmic autoantibody (ANCA)-negative pauci-immune systemic vasculitis who developed rapid recurrence of vasculitis involving skin, eye, and kidney allograft 1 month after cadaveric renal transplant while being maintained on cyclosporine, mycophenolate mofetil, and prednisolone. Despite early institution of aggressive treatment with plasma exchange, the disease remained uncontrolled and resulted in substantial morbidity and subsequent graft failure within 1 year post-transplantation. This case confirms that ANCA-negative vasculitides may recur in transplanted patients taking mycophenolate mofetil. Transplantation is contraindicated when active disease is evident.

Cuffed-tunneled femoral catheter for long-term hemodialysis

BACKGROUND

Hemodialysis access is a challenging problem in patients with exhausted dialysis access sites of their upper extremities. Femoral arterio-venous polytetrafluoroethylene (PTFE) graft is often necessary. The safety and efficacy of cuffed tunneled catheters at the femoral site for long-term hemodialysis has not been extensively studied.

METHODS

We inserted 14 cuffed-tunneled femoral catheters in 11 hemodialysis patients with exhausted dialysis access sites of their upper extremities. Access survival and risk of infection were compared with the 11 femoral PTFE grafts in 10 patients of our center during the same period. The choice of dialysis access was determined by the individual nephrologist. Access survival was defined as the achievement of a blood flow rate of at least 180 ml/min.

RESULTS

The median survival of tunneled femoral catheter and PTFE graft were 166 days and 560 days respectively (log-rank test, p = 0.33). Seven of the 14 tunneled femoral catheter remained in use 3 months after insertion. The incidence of catheter- or graft-related infection was 0.38 and 0.23 episodes per 100 catheter/graft days for tunneled femoral catheters and PTFE graft respectively (p = 0.6). Five tunneled catheters and one PTFE graft had to be removed because of infection. Blood flow rates achieved were comparable between tunneled femoral catheter and PTFE graft.

CONCLUSIONS

Our preliminary data suggest that the cuffed tunneled femoral catheter has reasonable access survival and an acceptable risk of infection. It may provide a safe and effective access for long-term hemodialysis patients with exhausted access in their upper extremities, especially high risk patients who are not suitable for femoral PTFE graft creation.

Grading of acute and chronic renal lesions in Henoch-Schönlein purpura

The renal outcome of 34 patients with Henoch-Schönlein purpura nephritis was assessed clinically and by grading acute and chronic renal lesions using a system we applied to primary IgA nephropathy. On a median follow-up period of 65 months, hypertension and the serum levels of creatinine and proteinuria at the time of renal biopsy were correlated with renal survival. Acute glomerular lesions including mesangial hypercellularity, endocapillary proliferation, necrosis, cellular crescents, and leukocytes infiltration were observed, respectively, in 41%, 12%, 50%, 29%, and 32% of the cases. Of these, only glomerular necrotizing lesion and cellular crescent were correlated with the renal survival. Chronic renal lesions based on a grading system applied to primary IgA nephropathy and assessing the extent of glomerular sclerosis (glomerular grading), of tubular loss and interstitial fibrosis (tubulointerstitial grading), and of hyaline arteriolosclerosis demonstrated correlation between these lesions, as well as with renal survival. On follow-up, these chronic renal lesions were predictors of subsequent clinical events associated with disease progression, such as impaired renal function, significant proteinuria, and development of hypertension. Despite some limitations related to the relatively small size, this series indicates that distinction of acute and chronic lesions of Henoch-Schonlein purpura nephritis is important for both the prognosis and management of patients.

Contribution of gene polymorphisms in the renin-angiotensin system to macroangiopathy in patients with diabetic nephropathy

The renin-angiotensin system is important in the control of hemodynamic status and pathogenesis of macrovascular disease, which is a major cause of morbidity and mortality in patients with type 2 diabetes with nephropathy. Serum angiotensin-converting enzyme (ACE) and angiotensinogen (Atg) levels are related to their respective gene polymorphisms. Seventy patients with type 2 diabetes with overt nephropathy (serum creatinine >/= 1.5 mg/dL) were studied. Serum ACE activity was measured by the spectrophotometric method. ACE deletion/insertion (D/I) and Atg M235T genotypes were determined by polymerase chain reaction. Patients with and without macroangiopathy were compared. Those with macroangiopathy had increased ACE activity (median, 60.9 U/L; range, 37.9 to 100 U/L versus without macroangiopathy, 47.9 U/L; range, 11.2 to 84.5 U/L; P = 0.01) and prevalence of ACE DD/DI genotypes (DD/DI:II: with macroangiopathy, 61%:39% versus without macroangiopathy, 34%:66%; P = 0.03). Multivariate analysis using age; sex; duration of diabetes; glycemic, blood pressure, and lipid level control; serum creatinine level; and presence of the ACE D allele showed that presence of the D allele (P = 0.03; odds ratio, 1.8; confidence interval, 1.1 to 3.1) and serum creatinine level (P = 0.0007) were independent risk factors for macroangiopathy. Association of the D allele became insignificant after serum ACE activity was included in the analysis in which only serum ACE activity (P = 0.004) and serum creatinine level (P = 0.01) were independent risk factors. Neither Atg M235T nor its synergistic effect with the ACE D allele showed an association with macroangiopathy. In conclusion, the ACE D allele is associated with macroangiopathy in Chinese patients with type 2 diabetes with nephropathy. The association is dependent on its effect on serum ACE activity, which is an independent risk factor for the development of macroangiopathy.