Inhibition of GATA2 in prostate cancer by a clinically available small molecule

Castration-resistant prostate cancer (CRPC) remains highly lethal and in need of novel, actionable therapeutic targets. The pioneer factor GATA2 is a significant prostate cancer (PC) driver and is linked to poor prognosis. GATA2 directly promotes androgen receptor (AR) gene expression (both full-length and splice-variant) and facilitates AR binding to chromatin, recruitment of coregulators, and target gene transcription. Unfortunately, there is no clinically applicable GATA2 inhibitor available at the moment. Using a bioinformatics algorithm, we screened in silico 2650 clinically relevant drugs for a potential GATA2 inhibitor. Validation studies used cytotoxicity and proliferation assays, global gene expression analysis, RT-qPCR, reporter assay, reverse phase protein array analysis (RPPA), and immunoblotting. We examined target engagement via cellular thermal shift assay (CETSA), ChIP-qPCR, and GATA2 DNA-binding assay. We identified the vasodilator dilazep as a potential GATA2 inhibitor and confirmed on-target activity via CETSA. Dilazep exerted anticancer activity across a broad panel of GATA2-dependent PC cell lines in vitro and in a PDX model in vivo. Dilazep inhibited GATA2 recruitment to chromatin and suppressed the cell-cycle program, transcriptional programs driven by GATA2, AR, and c-MYC, and the expression of several oncogenic drivers, including AR, c-MYC, FOXM1, CENPF, EZH2, UBE2C, and RRM2, as well as of several mediators of metastasis, DNA damage repair, and stemness. In conclusion, we provide, via an extensive compendium of methodologies, proof-of-principle that a small molecule can inhibit GATA2 function and suppress its downstream AR, c-MYC, and other PC-driving effectors. We propose GATA2 as a therapeutic target in CRPC.

Meta-analysis of antiplatelet therapy for IgA nephropathy

BACKGROUND

Antiplatelet agents have been widely used in the management of immunoglobulin A (IgA) nephropathy in the Japanese population. To systematically evaluate the effects of antiplatelet agents for IgA nephropathy, we conducted a meta-analysis of the published studies.

METHODS

Data sources consisted of MEDLINE, EMBASE, the Cochrane Library, Ityu-shi (Japanese medical database), and bibliographies from the studies. The quality of the studies was evaluated from the intention to treat analysis and allocation concealment, as well as by the Jadad method. Meta-analyses were performed on the outcomes of proteinuria and renal function.

RESULTS

Seven articles met the predetermined inclusion criteria. The use of antiplatelet agents showed statistically significant effects on proteinuria and renal function. The pooled risk ratio for proteinuria was 0.61 (95% confidence intervals (CI) 0.39-0.94) and for renal function it was 0.74 (95% CI 0.63-0.87).

CONCLUSIONS

Antiplatelet agents resulted in reduced proteinuria and protected renal function in patients with IgA nephropathy. However, studies of high-quality design were rare, and most studies assessed surrogate outcomes. More properly designed studies are needed to reach a definitive assessment of this matter.

Immunotactoid glomerulopathy with microtubular deposits, with reference to the characteristics of Japanese cases

We present the case of a 69-year-old man with nephrotic syndrome and renal insufficiency, who developed lobular glomerulonephritis. An electron microscopy examination of a renal biopsy showed microtubular structures of 24 nm in diameter in the subendothelial space and the paramesangial area. These deposits were PAS-positive and Congo red-negative, and revealed predominantly positive staining for kappa light chain. There was no evidence of diseases with highly organized glomerular deposits, such as amyloidosis, cryoglobulinemia, systemic lupus erythematosus or paraproteinemia. Therefore, the patient was diagnosed to have immunotactoid glomerulopathy (ITG). During a seven-year course he has not developed any disease known to be associated with organized glomerular immune deposits. Hence, we believe ITG occurred as a primary glomerular disease in this case. We also highlight cases of ITG with microtubular deposits that have been reported in Japan, compare these cases to previous reports, and show that the characteristics of the Japanese cases are male predominance; a high incidence of membranoproliferative glomerulonephritis (MPGN); a low incidence of monoclonal gammopathy and hematological malignancies and a higher incidence of hypocomplementemia.

Silent cerebral infarction in patients with type 2 diabetic nephropathy. Effects of antiplatelet drug dilazep dihydrochloride

BACKGROUND

To determine whether diabetic nephropathy is a risk factor for silent cerebral infarction and whether antiplatelet drug dilazep dihydrochloride decreases the occurrence of silent cerebral infarction in type 2 diabetes patients with microalbuminuria.

METHODS

Two hundred four type 2 diabetes patients (124 men, 80 women; age, median 56 years, range 42-74 years) and 60 healthy age-matched subjects (no diabetes, normal renal function) were recruited for brain magnetic resonance imaging. The diabetes patients included 40 without nephropathy (group A), 42 with microalbuminuria (20-200 microg/min) (group B), 44 with macroalbuminuria (>200 microg/min) and normal renal function (blood creatinine <132.7 micromol/L) (group C), 33 with chronic renal failure but not undergoing haemodialysis (blood creatinine >132.7 micromol/L; mean creatinine 335.9 micromol/L) (group D) and 45 undergoing haemodialysis (duration; median 4 years, range 3-6 years) (group E).

RESULTS

Silent cerebral infarction was found in 20, 29, 34, 45, 53 and 8% of group A, B, C, D, E and control patients respectively. The incidence of silent cerebral infarction was increased with diabetic nephropathy. Thirty group B patients with no silent cerebral infarction were divided into two groups: (B1) 15 treated with dilazep dihydrochloride and (B2) 15 not treated with dilazep dihydrochloride. Treatment continued for 24 months. The incidence of silent cerebral infarction was significantly lower in the dilazep-treated patients (6.7%) than in the untreated patients (33.3%) (p < 0.01).

CONCLUSIONS

These data suggest that diabetic renal dysfunction increases the risk of silent cerebral infarction and that dilazep dihydrochloride prevents its onset in early type 2 diabetic nephropathy patients.

Efficacy of prednisolone and mizoribine therapy for diffuse IgA nephropathy

OBJECTIVE

There have been only a few studies concerning oral prednisolone and mizoribine therapy for diffuse IgA nephritis (IgAN). We evaluated the efficacy of prednisolone and mizoribine therapy for diffuse IgAN.

METHODS

We enrolled 34 patients who had been diagnosed as having diffuse IgAN with severe proteinuria during the period from 1992 to 1999. Following diagnostic renal biopsy, the patients were treated with prednisolone, mizoribine, warfarin and dilazep dihydrochloride. The clinical features, laboratory data and pathological findings between pre- and post-therapy were investigated.

RESULTS

The mean urinary protein excretion after 6 months of treatment had decreased significantly compared to pre-therapy. The incidence of hematuria in post-therapy was lower than that of pre-therapy. The grading index decreased significantly from 4.8 +/- 2.1 at the first biopsy to 2.3 +/- 1.7 at the second biopsy (p < 0.001) and the staging index decreased significantly from 4.1 +/- 1.9 at the first biopsy to 2.7 +/- 2.4 at the second biopsy (p < 0.05). Macrophage infiltration and alpha-smooth muscle actin-positive cells in the glomerulus and interstitial region decreased significantly in post-therapy compared with pre-therapy. At the most recent follow-up, none of the 34 patients had renal insufficiency.

CONCLUSIONS

Our study suggested that prednisolone and mizoribine therapy is effective for those patients with the risk of progression of IgAN.

Dilazep hydrochloride, an antiplatelet drug, prevents progression of diabetic nephropathy in Otsuka Long-Evans Tokushima fatty rats

Diabetic nephropathy is a leading cause of end-stage renal disease in industrialized countries. Although the mechanisms for the development and progression of diabetic nephropathy are not fully understood, platelet activation may participate in its pathogenesis by promoting microthrombus formation. In this study, we investigated the effects of dilazep hydrochloride, an antiplatelet agent, on the development and progression of diabetic nephropathy in Otsuka Long-Evans Tokushima fatty (OLETF) rats, a type 2 diabetes mellitus animal model. Administration of dilazep hydrochloride significantly reduced the increase of urinary protein excretions and N-acetyl-beta-D-glucosaminidase (NAG) activity in OLETF rats. Furthermore, dilazep hydrochloride treatment prevented glomerulosclerosis and tubular atrophy and reduced positive staining for type IV collagen in the glomeruli of diabetic rats. These results indicate that platelet activation plays a dominant role in the development and progression of diabetic nephropathy. Our study suggests that dilazep hydrochloride is a valuable new drug for the treatment of diabetic patients with nephropathy.

Combination AST-120 and dilazep dihydrochloride therapy reduced urinary protein excretion and serum creatinine levels in patients with chronic renal failure

The effect of AST-120 and dilazep dihydrochloride on serum creatinine levels and urinary protein excretion was assessed in patients with chronic renal failure. We found that both drugs in combination provide an additive renoprotective effect over each drug in some chronic renal failure patients.

Effect of dilazep dihydrochloride on serum cardiac troponin T levels in hemodialysis patients

BACKGROUND/AIM

Cardiac troponin T is a highly sensitive marker for the detection of myocardial injury. We studied whether dilazep dihydrochloride affects cardiac troponin T levels in hemodialysis patients.

METHODS

Our study included 60 hemodialysis patients without symptoms of acute myocardial ischemia. We measured serum cardiac troponin T levels by the Elecsys troponin T assay and randomized 40 hemodialysis patients with left ventricular hypertrophy (LVH) into two treatment groups: a dilazep dihydrochloride group (300 mg/day, n = 20) and a placebo group (n = 20). Treatment was continued for 12 months.

RESULTS

There were no significant differences between pre- and postdialysis cardiac troponin T levels before treatment. LVH was noted in 40 patients out of 60 hemodialysis patients (67%). Cardiac troponin T levels were significantly higher in these patients (0.23 +/- 0.08 microg/l) than in hemodialysis patients without LVH (0.09 +/- 0.03 microg/l). Cardiac troponin T levels were reduced from 0.24 +/- 0.08 to 0.12 +/- 0.06 microg/l (p < 0.01) in patients treated with dilazep dihydrochloride. There were no change in cardiac troponin T levels in patients receiving placebo (from 0.21 +/- 0.08 at baseline to 0.20 +/- 0.07 microg/l).

CONCLUSION

Dilazep dihydrochloride may be effective in ameliorating myocardial damage in hemodialysis patients.

Steroid therapy and urinary transforming growth factor-beta1 in IgA nephropathy

Transforming growth factor-beta1 (TGF-beta1) has an important role in the pathogenesis of glomerular damage by influencing matrix metabolism. An association of TGF-beta1 with glomerulosclerosis and interstitial fibrosis has been shown in various renal diseases, suggesting that TGF-beta1 may serve as a diagnostic marker of glomerular diseases. The aim of this study is to determine the usefulness of urinary TGF-beta1 values to monitor therapeutic effects of steroids in patients with immunoglobulin A (IgA) nephropathy. Concentrations and activation rates of TGF-beta1 (mature/total) were determined in urine of patients with renal diseases by means of a double-antibody enzyme immunoassay. The urinary TGF-beta1 level before steroid therapy was compared with renal histological characteristics, creatinine clearance, and proteinuria in patients with a variety of renal diseases. Urinary excretion of total and mature TGF-beta1 was significantly greater in patients with crescentic glomerulonephritis and IgA nephropathy than in healthy controls, whereas the activation rate of urinary TGF-beta1 was similar among patients with other renal diseases. Urinary TGF-beta1 excretion at the time of renal biopsy significantly correlated with the degree of crescent formation in patients with IgA nephropathy, but not in those with glomerular sclerosis or tubulointerstitial fibrosis. Urinary excretion of total and mature TGF-beta1 was reduced in patients with IgA nephropathy after treatment with prednisolone (0.8 mg/kg/d) for 1 month. The activation rate of urinary TGF-beta1 also decreased significantly after steroid therapy. Urinary TGF-beta1 values therefore may be useful to assess disease activity or the effects of steroid therapy in patients with IgA nephropathy.

Effect of the antiplatelet drug dilazep dihydrochloride on urinary podocytes in patients in the early stage of diabetic nephropathy

OBJECTIVE

To determine whether the antiplatelet drug dilazep dihydrochloride affects the number of urinary podocytes in diabetic patients with microalbuminuria.

RESEARCH DESIGN AND METHODS

Fifty patients with type 2 diabetes and microalbuminuria (30 men and 20 women, mean age 48.6 years) and 30 age-matched control subjects (18 men and 12 women, mean age 49.2 years) were included in the study. No patients showed serum creatinine levels in excess of 2.0 mg/dl. Urinary podocytes were examined by immunofluorescence microscopy with monoclonal antibodies against podocalyxin.

RESULTS

Urinary podocytes were detected in 18 of the 50 microalbuminuric diabetic patients (mean, 1.3 cells/ml). Urinary podocytes were not detected in the remaining 32 patients or in the 30 healthy control subjects. Diabetic patients positive for urinary podocytes were divided into 2 treatment groups: a dilazep dihydrochloride treatment group (300 mg/day; n = 9, group A) and a placebo group (n = 9, group B). Treatments were continued for 6 months. In group A, microalbuminuria decreased significantly from 146 +/- 42 to 86 +/- 28 microg/min (P < 0.01) and urinary podocytes also decreased from 1.3 +/- 0.8 to 0.4 +/- 0.2 cells/ml (P < 0.01). However, in group B, microalbuminuria and urinary podocytes changed little over the study period.

CONCLUSIONS

Podocyte injury may occur in patients with early diabetic nephropathy, and dilazep dihydrochloride may be useful for preventing glomerular injury.

Cross over placebo control trial of dilazep in beta-thalassemia/hemoglobin E patients

An attempt was made to find better symptomatic treatment for beta-thalassemia/hemoglobin E (beta-thal/Hb E) patients in order to reduce their blood demand. Oral administration of dilazep was prescribed for these patients and a clinical trial was conducted over a 2-year period as a cross over placebo control study. Seventeen beta-thal/Hb E patients were enrolled in the study. All of them received dilazep and placebo for 10 months at different periods of time and were taken care of by the same doctor throughout the study. The blood demand of the same patients during the period of receiving dilazep with the period of receiving placebo, was 1.5 +/- 1.8 U/10 months versus 2.2 +/- 2.6 U/10 months, respectively. Thus dilazep showed a benefit in decreasing the blood demand by about 50% although the results did not reach statistical significance (p = 0.1). There was a statistical difference in hemoglobin concentration of the patients receiving dilazep compared with placebo (p = 0.038). While receiving dilazep the mean +/- SD hemoglobin level was 5.82 +/- 0.8 g/dl, significantly higher than while receiving placebo (5.66 +/- 0.9 g/dl) (p = 0.038). The liver, and renal function tests, and cardiac enzyme levels of the patients showed no significant changes throughout the study. However, one case had a problem with bleeding following tooth extraction whilst receiving dilazep and needed 1 unit of blood transfusion. In conclusion, administration of dilazep to patients with beta-thal/Hb E increased the patients' hemoglobin and reduced their blood demand with few side effects.

Hyperimmunoglobulin E syndrome associated with nephrotic syndrome

A 21-year-old man was admitted to Kure National Hospital with nephrotic syndrome in September 1996. He had suffered from an intractable pruritic skin rash and recurrent subcutaneous abscesses caused by the hyperimmunoglobulin E syndrome since the age of 18 months. Renal biopsy gave a diagnosis of membranoproliferative glomerulonephritis. Steroid therapy decreased urinary protein loss and hypoproteinemia, and his pruritic skin rash was improved. Patients with hyperimmunoglobulin E syndrome have a defective immune response, especially to Staphylococcus aureus infection. Continuous antigen stimulation may have caused this patient's renal histological damage as in immune complex glomerulonephritis.

Antiplatelet therapy decreases the incidence of erythropoietin-induced hypertension in predialysis patients

The observation that antiplatelet therapy may decrease the incidence of Epo-induced hypertension in dialysis patients remains a subject of particular interest. The aim of the present study was to test this hypothesis in patients at the predialysis stage. Predialysis patients with renal anemia were treated with EPO (6000 IU/week) for 6-12 months. Patients were divided into two groups, one of which received antiplatelet therapy and the other did not, and a comparison was made between them with respect to the incidence of EPO-induced hypertension. Logistic regression analysis was used to determine the risk factors for developing hypertension during the EPO therapy. Such predictors included age, gender, antecedent of hypertension, antiplatelet drugs and diabetes mellitus. Overall, 66 patients were enrolled in the study and 18 developed hypertension (27%). Out of the 35 patients not receiving antiplatelet therapy, 15 developed hypertension (43%). In contrast, out of the 31 patients receiving antiplatelet therapy, only 3 (10%) developed hypertension (p=0.003 by Chi square test). Multiple regression analysis showed that the best predictive variables for the development of hypertension were antecedent of hypertension (odds ratio: 0.064, p=0.0118), and use of antiplatelet drugs (odds ratio: 5.081, p=0.0295). The present data provide evidence that antiplatelet therapy may prevent EPO-induced hypertension in predialysis patients. However, the mechanism to explain such an effect still remains to be elucidated.

Elevation of plasma adenosine levels may attenuate the severity of chronic heart failure

Adenosine is known to be an endogenous cardioprotective substance. Since we have reported that adenosine levels increase in patients with chronic heart failure, we tested whether further elevation of the adenosine levels due to dipyridamole or dilazep for 6 months modulates the pathophysiology of chronic heart failure. In patients with chronic heart failure, either dipyridamole (300 mg/d n = 17) or dilazep (300 mg/d n = 5) were administered for 6 months. Twenty-two patients (mean +/- SE age 58 +/- 4 years old) attending a specialized chronic heart failure (CHF) clinic over 6 months and judged as in New York Heart Association (NYHA) function class II or III were examined. The other drugs used for the treatment of CHF were not altered during the study. There were 5 patients with CHF caused by ischemic heart diseases, and 17 patients with either valvular heart diseases or dilated cardiomyopathy. We found that increases in the plasma adenosine levels (202 +/- 34 and 372 +/- 74) nmol/L before and after dipyridamole administration, P < 0.005 ameliorate the severity of CHF (NYHA: 2.1 +/- 0.5 to 1.7 +/- 0.2). Both ejection fraction and maximal oxygen consumption increased. These improvements in the severity of chronic heart failure returned to baseline levels 6 months after discontinuation of dipyridamole. Comparable results were obtained in the dilazep protocol. We suggest that the elevation of plasma adenosine levels improves the pathophysiology of CHF.

A double-blind placebo control trial of dilazep in beta-thalassemia/hemoglobin E patients

Since the obtained results from the pilot study indicated that dilazep which was a membrane stabilizer would be benefit to treatment and prevention of anemia and chronic leg ulcer in beta-thalassemia/hemoglobin E (beta-thal/HbE) patients, the authors had continued the study in a second phase, ie a double blind placebo control trial. Twenty-seven beta-thal/HbE patients were recruited in the study. Eight patients who suffered from chronic leg ulcer were given dilazep. The rest of patients were given dilazep or placebo according to a randomized table. Hence, 16 patients received dilazep and 11 received placebo. When we compared the number of unit of blood transfusion, hemoglobin level, 2-3 DPG and P50 value between the dilazep and placebo groups using unpaired t-test, we found that there were no statistical differences in any of the parameters. However, when we compared the data within the group using paired t-test, there was statistical decrease in blood requirement after treatment in the dilazep group (p < 0.05). Concerning with the treatment of chronic leg ulcer, 3 in 8 patients were completely healed within 3 months, 4 in 8 patients were improved and 1 in 8 patients was not improved. There were complaints of skin itching and mild epigastric pain in placebo group but the liver function tests, kidney function tests and cardiac enzyme did not significantly change during the medication.

Cardioprotective effect of K-7259, a novel dilazep derivative, against ischemia-reperfusion damage in isolated, working rat hearts

Global ischemia (15 min) followed by reperfusion (10, 20 or 30 min) was performed in isolated, working rat hearts. Ischemia depressed mechanical function, which was not restored by reperfusion of 20 min. Preischemic administration of K-7259 (N,N'-bis[4-(3,4,5-trimethoxyphenyl)butyl]homopiperazine dihydrochloride) (1, 5 or 10 microM) decreased the function before ischemia, but it attenuated the ischemia-induced dysfunction during reperfusion (20 min). Postischemic administration of K-7259 (10 microM) or dilazep (20 microM) also attenuated the ischemia-induced dysfunction during reperfusion (30 min). Ischemia-reperfusion (10 min) increased the tissue malondialdehyde level, and postischemic administration of K-7259 (10 microM) or dilazep (20 microM) attenuated the malondialdehyde accumulation. K-7259 has a cardioprotective effect when given either before or after ischemia.

A study on dilazep: I. Mechanism of anti-ischemic action of dilazep is not coronary vasodilation but decreased cardiac mechanical function in the isolated, working rat heart

In the isolated, perfused working rat heart, ischemia (15 min) decreased the mechanical function and the tissue levels of adenosine triphosphate and creatine phosphate and increased the levels of lactate and free fatty acids. Reperfusion (20 min) did not restore the mechanical function, but restored incompletely the levels of metabolites, with the exception of free fatty acids, which increased further during reperfusion. Dilazep was given 5 min before starting ischemia until the end of ischemia. Dilazep at 5 or 10 microM decreased the cardiac mechanical function, but did not affect coronary flow in the pre-ischemic heart. Dilazep at 5 or 10 microM accelerated the recovery of mechanical function and coronary flow during reperfusion, and it attenuated metabolic changes induced by ischemia and reperfusion. Dilazep at 1 microM neither decreased the pre-ischemic mechanical function nor restored the mechanical function during reperfusion, although it attenuated the accumulation of free fatty acids during reperfusion. These results suggest that dilazep attenuates both ischemia- and reperfusion-induced myocardial damage and that the anti-ischemic action of dilazep is not due to coronary vasodilation but probably due to an energy-sparing effect and other effects that remain to be studied.

Nucleoside transport inhibitors enhance the infarct size-limiting effect of ischemic preconditioning

We recently observed that dipyridamole pretreatment significantly enhanced the infarct size (IS)-limiting effect of preconditioning (PC), which was attenuated by adenosine receptor antagonist. This potentiation of PC was interpreted to result from inhibition of nucleoside transport by dipyridamole, but contribution of other pharmacologic actions of dipyridamole could not be excluded. To confirm that inhibition of nucleoside transport leads to PC enhancement, we assessed alteration of mild PC by two different nucleoside transport inhibitors, dilazep and R75231, which, unlike dipyridamole, lack action on phosphodiesterase (PDE) and prostacyclin. Myocardial infarction was induced in rabbits by 30-min coronary occlusion and 72-h reperfusion. IS and area at risk (AAR) were determined by histology and fluorescent particles, respectively. Rabbits either were untreated or received dilazep (0.34 mg/kg intravenously, i.v.) or R75231 (0.05 mg/kg i.v.) before coronary occlusion. In other groups of rabbits, PC was conducted with 2-min ischemia and 5-min reperfusion with or without injection of the nucleoside transport inhibitor (0.34 or 0.10 mg/kg dilazep or 0.05 mg/kg of R75231) before PC. IS expressed as percentage of AAR (%IS/AAR) was 43.9 +/- 2.3% (SE) in untreated controls; dilazep (0.34 mg/kg) and R75231 alone did not modify IS (%IS/AAR = 50.6 +/- 4.7 and 42.7 +/- 11.9%, respectively). PC tended to reduce IS (%IS/AAR = 33.3 +/- 3.5%), but the combination of dilazep or R75231 with PC significantly limited %IS/AAR (%IS/AAR = 22.5 +/- 5.0% after low-dose dilazep plus PC, 27.6 +/- 4.9% after high-dose dilazep plus PC, and 19.9 +/- 3.6%, after R75231 plus PC).(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of pancreatic elastase on diabetic nephropathy

Pancreatic elastase has been shown to inhibit the thickening of glomerular basement membranes in experimental diabetic animals. We explored the clinical significance of the prolonged administration of pancreatic elastase on diabetic nephropathy, in patients whose blood glucose levels and blood pressure were controlled. Pancreatic elastase was administered for 12 months. Body weight levels, blood glucose levels, HbA1c values and blood pressure remained unchanged. Administration of 10,800 U of pancreatic elastase caused a significant decrease in albuminuria (before administration, 512.4 +/- 79.8 mg/g creatinine vs. 12 months after administration, 284.1 +/- 61.9 mg/g creatinine, P < 0.01, n = 28). In the contrast group (n = 18), no significant changes in albuminuria were observed after administration of 300 mg of dilazep dihydrochloride. Serum levels of creatinine and urinary levels of NAG and beta 2 MG were not affected by pancreatic elastase. The present study indicates a significant inhibitory effect of pancreatic elastase on increased albuminuria in diabetic patients.

Effects of an anti-platelet drug (dilazep) in IgA nephropathy: comparison of clinical effects with renal biopsy findings

To investigate renal biopsy findings arising in response to treatment with an anti-platelet drug in IgA nephropathy, 46 patients were treated with dilazep dihydrochloride (Dilazep), and a retrospective comparison was performed between the clinical effects and renal biopsy findings. After 6 months of treatment, 18 patients (39%) were judged to be improved if their proteinuria was ameliorated by a 25% or greater decrease with improved or persistent renal function. The group of improved patients exhibited mean decreased levels of urinary proteins in the range from 1.9 to 0.8 g/day after treatment (p < 0.01). By contrast, the unimproved group showed increased urinary proteins in the range from 1.2 to 2.0 g/day (p < 0.05). The improved group showed histological findings with fewer glomeruli exhibiting sclerosis and/or cellular crescents, with a lesser increase in mesangial matrix and with smaller tubulo-interstitial lesions than the unimproved group. By immunofluorescence, the improved group was found to have smaller amounts of glomerular IgA and IgG deposits. These findings suggest that an anti-proteinuric effect of Dilazep administration can be expected in patients with IgA nephropathy with relatively mild glomerulo-sclerotic lesions.

Dilazep prevents glomerulosclerosis in accelerated Masugi nephritis in the rat

The effects of Dilazep on immunologically induced glomerular injuries were examined. Accelerated Masugi nephritis in rats produced glomerulosclerosis with proteinuria following administration of a single dose of nephrotoxic serum (NTS). When 5 mg/kg/day of Dilazep had been administered prior to the NTS injection, the proteinuria was resolved rapidly after reaching a maximum level. The glomeruli 3 months later showed significant suppression of glomerulosclerosis and lesser adhesive lesions as compared to those in control rats with Masugi nephritis. On the other hand, when Dilazep was administered from 2 weeks after the injection of NTS, the rats displayed persistent proteinuria and glomerulosclerosis at similar levels to those in the Masugi group. Dilazep appears to exert some protective effects in the early stages of glomerular injuries induced by immunological mechanisms.

Effect of dilazep dihydrochloride against ischemia and reperfusion-induced disruption of blood-brain barrier in rats: a quantitative study

The effect of dilazep dihydrochloride (dilazep) against ischemia and reperfusion-induced disruption of blood-brain barrier (BBB) was quantitatively investigated in Slc:Wistar strain rats using Evans blue dye as a BBB destruction indicator. The forebrain of sham-operated animal had a small amount of the dye. A treatment of 3.5-h ischemia plus 2-h reflow extravasated the dye into the brain and markedly increased the dye content as compared with that of sham group (P less than 0.01 vs. sham group). Continuous infusion (i.v.) of dilazep during cerebral ischemia dose-dependently reduced the increase of the dye content, and a significant reduction was found at 3 mg/kg/h (P less than 0.05 vs. control group). Evans blue dye extravasation after ischemia was also greatly reduced in saline-perfused brains by the treatment with dilazep. Dilazep has been reported to inhibit edema formation in cerebral ischemia model of spontaneously hypertensive rats. These results suggest that dilazep prevents the ischemic damage of BBB, which may contribute to reduction of the brain edema.

Controlled clinical trial of nifedipine alone and in combination with dilazep in patients with angina pectoris

The present study was performed to see if the combined treatment with nifedipine and dilazep offers any advantage over monotherapy with nifedipine alone in angina of effort. Thirty-three patients out of 40 with classical stable angina of effort completed this double-blind, randomized, parallel design comparative clinical trial. Both nifedipine alone (15-60 mg) and in combination with dilazep (50 mg) three times a day produced a significant reduction in angina attacks, consumption of nitroglycerin tablets and increased exercise tolerance. There was, however, no difference in the reduction in these parameters between the two groups. There was no significant reduction in blood pressure both systolic as well as diastolic and rate pressure product both when nifedipine was given alone and when it was given in combination with dilazep. Laboratory data did not reveal any dysfunction of liver, kidney and hemopoietic system. The results obtained show that there was no beneficial effect of adding dilazep to nifedipine therapy in the treatment of angina pectoris.

Effect of urokinase on preservation of renal function in patients with diabetic nephropathy

Long-term effects of urokinase on the preservation of renal function in patients with diabetic nephropathy were evaluated. Twenty-nine adult patients with non-insulin-dependent diabetes mellitus and overt proteinuria were randomly divided into two groups. One group was treated with daily oral administration of dipyridamole or dilazep dihydrochloride and weekly intravenous administration of urokinase; the other group was treated with dipyridamole alone. There was a significant decrease in the amount of proteinuria in the first group after 3 months of the treatment compared with the second group. There was also a significant preservation of renal function in the first group after three years of treatment compared with the second group. It was concluded that continuous administration of urokinase in addition to antiplatelet agents is useful in the treatment of patients with diabetic nephropathy.

[Effect of dilazep on experimental vasospasm--evaluation of angiographical vasospasm and cerebral blood flow]

The effects of dilazep dihydrochloride on angiographic vasospasm and regional cerebral blood flow after subarachnoid hemorrhage were evaluated in double hemorrhage canine model. Severe angiographic vasospasm of basilar artery (percent reduction of intra-luminal diameter; 52.4%) was shown in untreated dogs. Daily intra-venous administration of dilazep (0.3 mg/kg for one hour) significantly inhibited angiographic vasospasm (percent reduction of intra-luminal diameter; 33.2%, p less than 0.05). Dilazep had a marked vasodilatory effect even in severe vasospasm in untreated dogs, and had a tendency to increase cerebral blood flow of the cerebral cortex in spite of reduced blood pressure. From these characteristics of action, intra-venous administration of dilazep would be useful agent for the treatment of cerebral vasospasm after subarachnoid hemorrhage.

[Effect of dilazep dihydrochloride on ischemia and reperfusion-induced cerebral injury in spontaneously hypertensive rats]

We examined the effect of dilazep dihydrochloride (dilazep) on ischemia and reperfusion-induced cerebral injury in spontaneously hypertensive rats (SHRs). Ataxia and loss of the righting reflex were noted in some SHR after 4 hr occlusion of the bilateral common carotid arteries; and 11 of 15 animals died within 72 hr after reperfusion. One hour after reperfusion, the cerebral water content increased significantly. The chemiluminescence value in the brain homogenate increased slightly during occlusion; and following reperfusion, there was a transient but marked further increase, indicating the acceleration of lipid peroxidation that resulted from free radical reactions. The i.v. infusion of dilazep (0.3-3 mg/kg/hr for 4 hr) during occlusion dose-dependently reduced the appearances of neurological symptoms and mortality during occlusion and after reperfusion. The increase in cerebral water content and chemiluminescence value were clearly prevented by dilazep (3 mg/kg/hr). It is concluded that dilazep possesses the ability to prevent the appearances of neurological symptoms and brain edema induced by ischemia and reperfusion. The suppression of lipid peroxidation may be involved in the mechanism of the preventive effect of dilazep on cerebral injury.

Thrombus formation on the aorta injured by angioplasty and its prevention with dilazep in atherosclerotic rabbits

To estimate the effect of dilazep in preventing restenosis after a transluminal angioplasty, we have attempted an animal experiment in which the efficacy of drug was tested on an angioplastic injury superimposed on to atherosclerotic lesions. Using a modification of Block's method, atherosclerotic lesions first were made in the rabbit aorta by an initial ablation of the endothelium, followed by successive cholesterol feedings. Then, for our second step, an angioplastic injury was inflicted on the atherosclerotic lesions. The thirty two rabbits used were divided into 3 groups: those given dilazep (100 micrograms/kg i.v.), those given dipyridamole (100 micrograms/kg i.v.) and a control group that was given the same volume of 0.9% saline. The angioplastic area in which thrombi developed was semiquantitatively measured and compared among all three groups. The mean value of the thrombus area in the dilazep group was 60% smaller and the distribution pattern of the thrombus by size was found to be composed of smaller thrombi than those of the control group. Dipyridamole showed the same trend as did dilazep, but less effectively. Our animal model and semiquantitative evaluation method that we employed were found useful from the view point of an easy applicable and inexpensive methodology. Our results point towards the possible clinical use of dilazep in the future, so as to prevent thrombus formation, which seems to cause the restenosis phenomenon that often occurs in patients who have undergone a coronary angioplasty.

Effects of dilazep in evolving myocardial infarction in dogs: a biochemical study

Mongrel dogs of either sex with ligation of their left anterior descending coronary artery were employed for the present study to investigate the biochemical basis of the cardioprotective action of dilazep. Dilazep (0.2 mg/kg intravenous) was administered 20 minutes after coronary arterial occlusion. Ligation of the artery for 40 minutes increased the tissue lactate concentration and decreased the adenosine triphosphate molecules within the occluded bed. Dilazep decreased the lactate concentration and improved the adenosine triphosphate content of this bed significantly. Dilazep also lowered the tissue cyclic adenosine monophosphate concentration and free fatty acid extraction of the ischemic myocardium as studied 40 minutes after coronary arterial ligation. It can be inferred that less free fatty acid extraction and calcium antagonistic action of dilazep helps in restoring mitochondrial function. Furthermore, decreased tissue lactate concentration resulted after better perfusion of the occluded bed and helped in greater generation of adenosine triphosphate molecules. These favorable biochemical and metabolic changes contribute to the cardioprotective action of dilazep.

Therapeutic tolerance, hemodynamic effects, and oral dose kinetics of dilazep dihydrochloride in hypertensive patients

The oral dose metabolism of dilazep dihydrochloride [tetrahydro-1H-1,4-diazepine-1,4(5H)-dipropanol 3,4,5-trimethoxybenzoate] was examined in six hypertensive patients receiving a single oral dose of 600 mg of dilazep (3-3.8 mg/kg BW). Blood was collected at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 10, and 24 h after administration of the dose and urine was collected for three time intervals of 0-4 h, 4-10 h, and 10-24 h. Dilazep concentrations in blood and urine were determined by high-performance liquid chromatography. Dilazep decayed monoexponentially with a mean elimination rate constant of 0.27 +/- 0.13 h-1 and a mean half-life of 3.04 +/- 1.34 h. The mean tmax of absorption was 1.40 +/- 0.82 h. With maximally tolerated chronic doses, the steady-state concentration measured at 1 week was 25.6 ng/mL in a patient receiving 300 mg daily (100 mg TID) for 3 weeks, and dilazep concentration increased with the dose in others for up to a 600-mg dose daily. Dilazep did not produce any significant changes in heart rate and blood pressure after a single oral dose or during chronic dosing. There was no correlation between blood dilazep levels and the changes in heart rate and blood pressure. In three additional patients, oral dilazep dihydrochloride titrated gradually to maximally tolerated doses (900 mg daily) failed to produce significant effects on biochemical and neurohumoral measurements, and hemodynamic parameters as well as ventricular functional indices measured by radionucleide methods. Oral dilazep administration in maximally tolerated doses is devoid of effects on blood pressure and cardiac hemodynamic function.

Intravenous dilazep reduces blood pressure and peripheral vascular resistance in humans

Dilazep, a coronary vasodilating drug with adenosine-mediated activity, was tested (acute double-blind study versus placebo) for its antihypertensive activity in 12 patients who had mild to moderate hypertension. Dilazep (0.2 mg/kg body weight by IV infusion for ten minutes) significantly reduced systolic and diastolic blood pressure (random-zero sphygmomanometer) on average by 13.3 and 10.6 mm Hg respectively. The antihypertensive effect started rapidly, reached its maximum 20 minutes after administration, and lasted for 90 minutes. Heart rate significantly increased between 10 and 30 minutes. The antihypertensive effect of dilazep was associated with a relevant vasodilating effect as demonstrated by the changes in upper limb blood flow (strain-gauge plethysmography, +32%; P less than .001) and vascular resistance (-29%, P less than .001). The maximal reduction of vascular resistance was directly correlated to its baseline value. For these characteristics of action, at least in acute administration, dilazep would be useful agent for the treatment of high blood pressure in mild to moderately hypertensive patients.

Treatment of schistosomiasis by purine nucleoside analogues in combination with nucleoside transport inhibitors

In contrast to their effects on mammalian cells, the nucleoside transport inhibitors nitrobenzylthioinosine 5'-monophosphate (NBMPR-P) dilazep, benzylacyclouridine (BAU), and to a lesser extent, dipyridamole have no significant effect on the in vitro uptake of adenosine analogues by Schistosoma mansoni [el Kouni and Cha, Biochem. Pharmac. 36, 1099 (1987)]. Coadministration of either NMBPR-P or dilazep with potentially lethal doses of tubercidin (7-deazaadenosine), nebularine or 9-deazaadenosine protected mice from the toxicity of these adenosine analogues. Dipyridamole caused partial protection, whereas BAU did not protect the animals from this toxicity. Toyocamycin caused delayed mortality (after 16 weeks) which could not be prevented by coadministration of NBMPR-P. In S. mansoni infected mice, treated with the combination of NBMPR-P and 9-deazaadenosine was not effective against the parasite. On the other hand, the combinations of NBMPR-P or dilazep with either tubercidin or nebularine were highly toxic to the parasite but not the host. Combination therapy caused a marked reduction in the number of pairing of worms. Effectiveness of combination therapy could also be noted by a drastic decrease in the number of eggs in the liver and small intestine. All eggs found were dead, indicating a direct effect on ovigenesis. Although dipyridamole was less effective than NBMPR-P or dilazep in protecting the host from the toxicity of tubercidin or nebularine, the combinations with dipyridamole produced similar significant therapeutic effects in animals that survived. Mice receiving the combination of tubercidin (or nebularine) plus NBMPR-P or dilazep, as well as those that survived the combination with dipyridamole, appeared healthy and were found to have normal size livers and spleens. These results suggest that highly selective toxicity against schistosomes can be achieved by coadministration of various nucleoside transport inhibitors with adenosine analogues.

Mechanism of myocardial protective action of dilazep during ischaemia and reperfusion

The aim of this study was to investigate if dilazep is able to reduce with a direct protective action on the myocardium the deleterious effects caused by ischaemia and reperfusion. For this purpose we used an isolated rabbit heart preparation. The hearts were either perfused aerobically or made totally ischaemic for 60 min (by abolishing coronary flow) or made ischaemic for 60 min and then reperfused for 30 min. Ischaemic and reperfusion damage was measured in terms of alteration in mechanical function, lactate and CPK release, mitochondrial function and tissue content of Adenosine Triphosphate (ATP), Creatine Phosphate (CP) and calcium. Dilazep (10(-5) M) was administered in the perfusate either 20 minutes before ischaemia or only during post-ischaemic reperfusion. Ischaemia induced a decline of the endogenous stores of ATP and CP, followed by an alteration of calcium homeostasis with increase of diastolic pressure, mitochondria calcium overload and impairment of the oxidative phosphorylating capacities. On reperfusion, tissue and mitochondrial calcium increase the capacity of the mitochondria to use O2 for state III respiration was further impaired and the ATP-generating capacity reduced. Diastolic pressure increased and there was only a small recovery of active tension generation associated with massive CPK release. Administration of dilazep before ischaemia induced a negative inotropic effect which, in turn, resulted in a slowing of the rate of CP and ATP depletion during ischaemia. This protected the hearts against the ischemic, and reperfusion-induced decline in the ATP-generating and O2-utilizing capacities of the mitochondria. In addition, there was a less marked increase in tissue and mitochondrial Ca++, CPK and lactate release were reduced and the recovery of developed pressure on reperfusion was significantly increased. Administration of dilazep during reperfusion failed to modify the exacerbation of ischaemic damage caused by the readmission of coronary flow. These data suggest that dilazep benefits the ischaemic myocardium via an ATP sparing action.

Cardiovascular effects of a single high dose of dilazep by oral route

The acute hemodynamic effects on the coronary and systemic arteries of a single high dose of dilazep given orally (200-400 mg; 3-5 mg/kg) were studied in 25 anginal patients who, for diagnostic reasons, underwent cardiac catheterization and coronary angiography. From 20 to 30 min after drug administration, systemic vascular resistance (1666 +/- 348 to 1367 +/- 312 dyn X sec X cm-5, P less than 0.05) and left ventricular end-diastolic pressure (16.5 +/- 5 to 12 +/- 4.4 mm Hg, P less than 0.01) decreased significantly. The heart rate rose from 74 +/- 10 to 84 +/- 12 beats/min (P less than 0.05), while the cardiac index, dp/dt max and pulmonary arteriolar resistance did not change significantly. Concomitantly, coronary blood flow significantly increased, coronary resistance was reduced by 42% (P less than 0.01) while myocardial oxygen consumption was unchanged. The increase in mean coronary arterial diameter was by 22-25%. It is concluded that dilazep has a prompt and potent vasodilating action even after oral administration. The drug is therefore useful in the chronic treatment of ischemic heart disease.

Effect of dilazep on hemoglobin-oxygen affinity in patients with ischemic heart disease

The effects of orally administered dilazep, an antianginal drug, on the hemoglobin-oxygen affinity were studied in 31 cases with ischemic heart disease. Prior to medication, the mean P50 value was 29.2 +/- 1.65 mmHg. There were no significant differences in the P50 value according to the age of patient or the severity of the coronary arterial disease. Acute effects of dilazep were studied in 29 patients. The 30 min and 60 min post-administration P50 values increased significantly to 30.2 +/- 2.55 mmHg and 30.4 +/- 2.31 mmHg, respectively. Eight patients were administered 300 mg of oral dilazep daily for 4 weeks. Three of 4 in whom exercise tolerance improved showed increases in P50. No changes in various factors which might affect the P50 value, including 2,3-DPG, were found.

Rabbit hearts for the critical evaluation of drugs to reduce the size of experimentally produced acute myocardial infarction

Using more than 500 rabbits, we found that the rabbit heart is a good model for the evaluation of drugs which affect acute myocardial infarction (AMI) size. When the ratio of the epicardial coloration area to the long axis length of the left ventricle was controlled immediately after the ligation of the left anterior descending coronary artery and small branches of the left circumflex artery, it was possible to estimate the size of the ischemic region because AMI region in rabbit heart was always transmural. The necrotic region in the left ventricle was determined by phosphorylase histochemistry 24 hours after the operation. The incidence of arrhythmia and death following the operation was negligible. Then, we evaluated several drugs to examine their effects on AMI size. Propranolol (1, 2, and 4 mg/Kg) and verapamil (0.25, 0.5, and 1.0 mg/Kg) reduced AMI size, although the mortality and AMI size increased at higher doses of verapamil. Another Ca2+ antagonist, diltiazem (2 mg/Kg) and an adenosine potentiator, dilazep (2 mg/Kg) also decreased AMI size, while nicardipine, a water soluble, photoresistant nifedipine analogue (0.01, 0.05, and 0.1 mg/Kg) did not show a significant effect. These data suggest that this rabbit model is useful for assessing drug effects on AMI size and that the mechanism(s) of action of nicardipine may differ from other Ca2+ antagonists.

Dilazep-induced reduction of ischemic necrosis in rats with coronary artery occlusion

To assess whether dilazep reduces myocardial necrosis we assigned 72 rats that survived coronary artery occlusion to 3 groups. The first control group (n = 26) received coronary occlusion and was untreated. The second group (n = 21) received coronary occlusion and was treated with dilazep (150 micrograms/kg s.c.) every 8 hours for 48 hours. The third group (n = 25) was sham-operated. Forty-eight hours later the creatine-kinase activity of the left ventricle was measured. The calculated left ventricular fraction that survived the occlusion was larger in dilazep-treated rats (44.5 +/- 4.1% of left ventricle) than in controls (31.2 +/- 3.2%; P less than 0.05). Twenty-six more rats also underwent coronary occlusion; 12 were controls and the remaining 14 were treated with dilazep at the same time and dose as before and killed 21 days after occlusion. Infarct size was evaluated on histological sections of the hearts by planimetry. The amount of left ventricle preserved from necrosis was larger in dilazep-treated rats, 82.1 +/- 0.9%, compared to controls 69.5 +/- 1.4% (P less than 0.05). Dilazep seems effective in preserving myocardial tissue from ischemic necrosis, and its beneficial effects are long-lasting, producing permanent reduction of infarct size.

A study on the noninvasive evaluation of coronary vasodilating drugs with Thallium-201 myocardial imagings

To evaluate clinically the effects of coronary vasodilating drugs, isosorbide dinitrate (ISDN), dilazep (DL), and dipyridamole (DP), on the myocardial perfusion, quantitative analysis of Thallium-201 myocardial imagings was performed before and after their sublingual or oral administration in 17 patients with ischemic heart disease (IHD) and 9 normal volunteers. The ratio of total myocardial blood flow to cardiac output (TMBF/CO) and the ratio of ischemic regional myocardial blood flow to cardiac output(RMBF/CO) were calculated according to the indicator fractionation principle. The ratio of radio-activity of infarcted region to total myocardium (R/T) was also calculated to judge the degree of scintigraphic defect objectively. There were increases in TMBF/CO in 7 of 9 patients after ISDN, 4 of 5 patients after DL, and 2 of 6 patients after DP. Increases in RMBF/CO were observed in all patients studied after ISDN and DL, whereas in 2 of 6 patients after dipyridamole. Decreases both in RMBF/CO and R/T which suggest coronary steal phenomenon were observed in 4 of 6 patients after DP. The myocardial imaging technic is a useful noninvasive method for clinical evaluation of coronary vasodilating drug.