Fulminant elderly adult-onset Still disease effectively treated with tocilizumab and methotrexate: A case report

RATIONALE

Adult-onset Still disease (AOSD) is a rare inflammatory disease of unknown etiology. AOSD is common in young or middle-aged adults; however, in recent years, there have been increasing reports of elderly AOSD. Differentiating AOSD from diseases such as infections and malignancies is difficult. Moreover, rare fulminant AOSD cases with resistance to corticosteroids and immunosuppressive drugs have been reported.

PATIENT CONCERNS

An 80-year-old woman presented with flaccid fever, generalized arthralgia, and erythema of the anterior chest for 2 weeks. On day 5 of hospitalization, the patient developed pleural effusion with hypoxemia and her vital signs indicated rapid progression to shock. During the clinical course, the levels of inflammatory markers, including maximum level of ferritin and white blood cells (WBCs) were elevated (252,796 ng/mL and 86,500/μV, respectively) with disseminated intravascular coagulation syndrome (DIC) and macrophage activation syndrome (MAS).

DIAGNOSIS

The patient was diagnosed with elderly AOSD as per the Yamaguchi criteria for AOSD. The state of disease was extremely severe with rapid progression and was, thus, categorized as a fulminant form of elderly AOSD.

INTERVENTIONS

The patient was treated with prednisolone (PSL) pulse therapy (1000 mg/d) twice and plasma exchange in the intensive care unit for the primary disease and shock. Although she recovered from shock, she developed DIC and MAS. Methotrexate (MTX; 10 mg/d) improved the DIC and MAS. However, severe pleuritis recurred and the patient developed pericarditis; her primary disease was poorly controlled. Finally, tocilizumab (TCZ) was introduced using interleukin-18 (IL-18) as a surrogate marker. The IL-18 level was measured repeatedly following admission, with the peak level (170,000 pg/mL) recorded on the 75th day of hospitalization, immediately prior to introducing TCZ.

OUTCOMES

The combined use of MTX, TCZ, and PSL was effective in suppressing elderly AOSD, which was unsuccessfully controlled with MTX and PSL. Frequent monitoring of IL-18 levels proved useful for differentiating elderly AOSD from other diseases.

LESSONS

A fulminant form of elderly AOSD was treated with a combination of MTX, TCZ, and PSL. Repeated monitoring of IL-18 levels can be useful for decision-making in treating elderly AOSD.

Acute Pancreatitis Coincided with Multiple Arteriolar Aneurysms in a Patient with Polyarteritis Nodosa

A 78-year-old man presented to our hospital with a history of 10kg weight loss within 6 months previously, and general fatigue and fever for 2 and 1 months, respectively. On hospitalization, the patient was diagnosed with polyarteritis nodosa after multiple microaneurysms were observed in the liver, kidney, pancreas, and mesenteries. He achieved remission with the administration of 1,000mg methylprednisolone for 3 days, followed by prednisolone (55mg/day). Steroids were successfully tapered with no re-elevation in inflammation. Two months after the administration of steroids, the patient complained of acute abdominal pain, and developed severe acute pancreatitis. During treatment for pancreatitis, the patient died due to septic shock and disseminated intravascular coagulation. An autopsy revealed necrotizing vasculitis in the intrapancreatic arteries and ischemia of the downstream arterioles resulting in acute pancreatitis.

18F-fluorodeoxyglucose-positron emission tomography/computed tomography for the diagnosis of polymyalgia-like illnesses: a retrospective study

Background

Various inflammatory conditions may present with musculoskeletal symptoms similar to those of polymyalgia rheumatica (PMR). We investigated findings on ¹⁸F-fluorodexoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) images that may differentiate PMR from polymyalgia-like illnesses.

Methods

We analyzed data from 25 patients with new-onset polymyalgia-like illnesses who fulfilled Bird's diagnostic criteria for PMR and had undergone FDG-PET/CT scan. To assess the uptake by major joints and synovial bursae, particularly at PMR-specific sites (shoulder, sternoclavicular, and hip joints, interspinous bursae, ischial tuberosities, and greater trochanters), we used visual scoring system to score FDG uptake: 0, no uptake (same as bone); 1, slight uptake; 2, moderate uptake (same as the liver); 3, greater uptake than the liver; and 4, uptake as strong as in the cerebellum.

Results

The final diagnoses were PMR in 17 patients and non-PMR in eight patients (three malignancies, two infections, one cholesterol crystal embolism, one ANCA-associated vasculitis, and one undefined diagnosis). Although the serum MMP-3 levels were significantly higher in patients with PMR, C-reactive protein and erythrocyte sedimentation rate mean values did not differ between the two groups. In PMR-specific sites, FDG accumulations were observed in all cases of PMR, with a high PET-positive score of 2.00 (range, 0-3), but it was low in non-PMR cases, with a PET-positive score of 1.00 (range, 0-3).

Conclusions

The FDG accumulation patterns in polymyalgia-like illness differ from those in PMR, despite the similar clinical presentations of both conditions. An FDG-PET/CT scan is useful for differentiating PMR from other polymyalgia-like illnesses.

Refractory Dermatomyositis Complicated with Myelodysplastic Syndrome

We herein describe a case of refractory dermatomyositis (DM) complicated with myelodysplastic syndrome (MDS). Despite intensive immunosuppressive therapies, the activity of myositis, skin ulcers, and interstitial pneumonia did not improve. The patient ultimately died following the progression of interstitial pneumonia. There are few reports of DM accompanying MDS to date, and any association in the pathogenesis between the two is still unclear. However, underlying MDS may have the potential to influence the therapeutic response of DM.

P3-14-10: Early Predictive Value of Non-Responder to Docetaxel in Neoadjuvant Chemotherapy in Breast Cancer Using 18F- FDG-PET

Background; Clinical response is determined after several cycles of chemotherapy by changes in tumor size in imaging procedures including ultrasound, MRI or CT. The aim of this prospective study was to early detect non-responder to docetaxel (DTX) in neoadjuvant chemotherapy using 18F- FDG-PET in patients with breast cancer. Method; 41 patients were eligible for this study. 37 were assessable (4 were not eligible or not evaluable) with Invasive carcinoma (T1:10%, T2: 83%). All 37 patients were treated with 4 cycles of docetaxel (75mg per square meter) followed by 4 cycles of FEC(cyclophosphamide/epirubicin/fluorouracil: 500/75/500 mg per square meter) before surgery. 18F-FDG-PET response rate was evaluated between before and after the first cycle of DTX. 18F-FDG-PET images were analyzed by standardized uptake value, SUVmax. Clinical response is determined by reduction rate in tumor size with MRI (RECIST criteria) between before the first cycle and after the fourth cycle of DTX. Pathological response evaluated by core needle biopsy after the fourth cycle of DTX.

Result; 18F-FDG-PET response rate after the first cycle of DTX showed correlation with tumor size reduction rate with MRI image after the fourth cycle of DTX (r=0.746)(P <.001). 0 out of 8 patients (0%) revealed cPR with MRI changes in SUV decrease less than 18% (p <.001). 8 out of 13 patients (62%) showed cPR (cCR = 0) with MRI in SUV decrease over 19 to 44% (P <.001). 9 out of 16 patients (56%) were cPR, and 7 out of them (44%) showed cCR with MRI in SUV decrease over 45% (P <.001).

Conclusion; Changes of 18F-FDG SUVs in tumors were statistically significantly different between responding and nonresponding (P <.001). SUV decrease less than 18% after the first cycle indicated potential failure to DTX in neoadjuvant chemotherapy.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-14-10.

A case of multicentric Castleman's disease having lung lesion successfully treated with humanized anti-interleukin-6 receptor antibody, tocilizumab

This report presents the case of a patient demonstrating multicentric Castleman's disease (MCD) with a lung lesion that was successfully treated with an anti-interleukin-6 receptor antibody, tocilizumab in combination with corticosteroid and tacrolimus. A 43-yr-old female with abnormal shadows on a chest X-ray was referred to the hospital for further examination. She was diagnosed as having MCD based on the characteristic pathology of inguinal lymph node, lung lesions, laboratory data, and undifferentiated arthritis. Corticosteroid and rituximab therapy did not fully ameliorate the symptoms; thus, the therapeutic regimen was changed to include tocilizumab, oral corticosteroid and tacrolimus. This regimen resulted in clinical remission and the dose of tocilizumab and corticosteroid could be tapered. Tocilizumab in combination with corticosteroid and tacrolimus may therefore be a beneficial treatment regimen for lung lesions associated with MCD.

Clinical characteristics of patients with both anti-U1RNP and anti-centromere antibodies

OBJECTIVE

To clarify the clinical characteristics of patients having both anti-U1RNP antibodies (anti-U1RNP) and anti-centromere antibodies (ACA) in comparison to subjects having either anti-U1RNP or ACA alone.

SUBJECTS AND METHODS

One hundred and fifty-six subjects who had anti-U1RNP and/or ACA were enrolled. They were classified into three groups: anti-U1RNP alone group (n = 64); ACA alone group (n = 82); and anti-U1RNP+ACA group (n = 10). The anti-U1RNP alone and ACA alone groups were also divided into the low-titre and the high-titre subgroups, respectively. The frequencies of the specific clinical findings and laboratory data were compared among the groups or subgroups.

RESULTS

The frequencies of persistent proteinuria or lupus nephritis (LN, 50.0%) and primary biliary cirrhosis (PBC, 30.0%) in the anti-U1RNP+ACA group were higher than that in the anti-U1RNP alone group (17.2%, p<0.01; 3.1%, p = 0.075; respectively). The frequencies of systemic lupus erythematosus (SLE, 60.0%), persistent proteinuria or LN (50.0%), anti-Ro (70.0%), and anti-La (30.0%) in the anti-U1RNP+ACA group were higher than those in the ACA alone group (11.0%, p<0.01; 4.9%, p<0.001; 23.2%, p<0.01; and 6.1%, p = 0.085; respectively). The frequency of systemic sclerosis (SSc) in the high-titre subgroup (30.0%) was higher than that in the low-titre subgroup (11.8%) in the anti-U1RNP alone group, without significance (p = 0.072). The frequency of interstitial pneumonia in the high-titre subgroup (26.8%) was higher than that in the low-titre subgroup (2.4%) in the ACA alone group (p<0.01).

CONCLUSIONS

The clinical characteristics of patients with anti-U1RNP+ACA were clarified in comparison to subjects having either anti-U1RNP or ACA alone.

The relationships between titers of anti-Ro or anti-La as measured by ELISA and salivary production rate with age correction

The objective of this work was to clarify the clinical significance of titers of anti-Ro and anti-La, the relationships between titers of either anti-Ro or anti-La, and salivary production rate (SPR). These autoantibodies were titrated using enzyme-linked immunosorbent assay. The Saxon test was performed to measure SPR. Fifty-one females who had anti-Ro but not anticentromere antibodies or anti-U1RNP were enrolled. SPR decreased significantly with age. In order to exclude the effect of aging on SPR, we calculated the "SPR with age correction." According to the results of a multiple regression analysis, only the anti-La titer was significantly associated with SPR with age correction. The distribution pattern of the anti-La titers consisted of two subgroups (with a titer index cutoff of 100.0): a negative anti-La titer (anti-La<25.0) and low anti-La titer (25.0or=100.0). The concentration of serum IgG and the frequency of Sjögren's syndrome in the high anti-La titer group were significantly higher than those in the negative anti-La and low anti-La titer group. Several new aspects of the clinical significance of titrating anti-Ro and anti-La in comparison with SPR have been revealed.

Negative correlation of anti-U1RNP antibody titers and the amount of salivary secretion with age correction

OBJECTIVE

The aim of this study was to reveal whether or not the presence of anti-U1RNP antibodies is associated with a low amount of salivary secretion (ASS).

SUBJECTS AND METHODS

Twenty females (mean age 49+/-12 years) who had anti-U1RNP but not ACA, anti-Ro, or anti-La antibodies (anti-U1RNP-positive group), and 65 control females (mean age 50+/-12 years) were included in this study. The saxon test was performed to measure the ASS.

RESULTS

After a correction for age by ANCOVA, ASS in the anti-U1RNP-positive group was significantly lower than ASS in the control group (p <0.001). In the control group, ASS was not significantly decreased with advanced age (r=-0.140, p=0.211). In the anti-U1RNP-positive group, ASS was decreased with age, without a significant difference (r=-0.379, p=0.100). In the next analysis, we introduced 'ASS with age correction', assuming that all subjects in the anti-U1RNP-positive group were 49 years of age. A negative correlation between the titers of anti-U1RNP antibodies and the ASS with the age correction in the anti-U1RNP-positive group was noted (r=-0.520, p=0.019). The log of the antinuclear antibodies titers, or titers of rheumatoid factor was significantly correlated with the titers of anti-U1RNP antibodies, respectively (r=0.466, p=0.038 and r=0.595, p=0.006; respectively). The pathological findings of minor salivary gland biopsy in 2 subjects were compatible with Sjögren's syndrome; one subject showed moderate lymphocytic infiltration.

CONCLUSION

The presence of anti-U1RNP antibodies is associated with reduced ASS.

Primary biliary cirrhosis in female subjects with sicca-associated antibodies

The aim of this study is to clarify the time course of primary biliary cirrhosis (PBC) in subjects possessing anticentromere antibodies (ACA), anti-Ro, and/or anti-La antibodies, and who used alkaline phosphatase (ALP) as a serological marker for PBC. Female subjects (n = 165), who had at least one of ACA, anti-Ro, and/or anti-La, were enrolled in this study. Groups A (ACA alone, n = 44), B (anti-Ro alone, n = 54), E (anti-Ro and anti-La, n = 52), and DFG (ACA with anti-Ro and/or anti-La, n = 14) were analyzed. Healthy females (n = 65) were used as a control. The frequencies of the PBC in groups A (13.6%) and DFG (14.3%) were higher than those in groups B (1.9%) and E (0.0%). The ALP levels increased with age in groups A and DFG and slightly increased with age in groups B and C, and the control group. After correcting for age by analysis of covariance, a comparison of ALP levels among the groups not having anti-M(2) was as follows: group A falling dots group DFG > group B falling dots group E falling dots the control group. The subjects with ACA might thus have PBC more frequently than either those with anti-Ro and/or anti-La, or the control subjects.

Intermittent intravenous cyclophosphamide pulse therapy for the treatment of active interstitial lung disease associated with collagen vascular diseases

The availability of intravenous cyclophosphamide (CYC) pulse therapy for collagen vascular diseases (CVD)-associated interstitial lung disease (ILD) has been indicated. However, the standard protocol concerning the dosage and the interval of CYC infusion has not yet been established. The aim of this study is to elucidate the efficacy and the safety of our "divided administration" protocol of CYC for the treatment of CVD-ILD. The treatment protocol consists of two steps: step 1, CYC 400-500 mg at 10-day intervals for at least 30 days, and step 2, CYC 500 mg at 14-day intervals for at least 4 weeks. The ILD activities were monitored by respiratory symptoms, serum levels of KL-6 (a serological marker of IP), chest computed tomography (CT), and pulmonary function tests. Seventeen patients [nonspecific interstitial pneumonia (NSIP), 12 patients; usual interstitial pneumonia (UIP), 4; lymphocytic interstitial pneumonia (LIP), 1] accomplished the study protocol. The sessions of CYC infusion ranged from 5 to 20 (mean, 8.3). In all patients, respiratory symptoms were improved and the serum levels of KL-6 were decreased (from 1572 +/- 904 to 978 +/- 392 U/ml; P < 0.01). Chest CT findings were improved in 4 patients (23.5%): they were all classified as NSIP; not deteriorated, 13 patients (76.5%). An improvement in the vital capacity percentage (%VC) was recognized in 10 patients (78.6%) and in diffusing capacity of carbon monoxide (%DLco) in 8 patients (61.5%). Nevertheless, mean %VC and mean %DLco did not change significantly. No major adverse event(s) occurred. The efficacy and safety of our "divided administration" protocol of CYC for CVD-ILD was demonstrated.

Outcomes of hepatic artery infusion therapy for hepatic metastases from colorectal carcinoma after radiological placement of infusion catheters

AIM

The aim of this study is to evaluate the safety and efficacy of hepatic artery infusion (HAI) of 5-fluorouracil (5FU) for patients with liver metastases from colorectal carcinoma after radiological placement of infusion catheters.

METHODS

Forty-two patients with liver metastases from colorectal carcinoma received radiological placement of infusion catheters using the distal fixation method. They received continuous HAI of 5FU 1,000-1,500mg for 5h weekly or biweekly. Tumor status was assessed by chest-abdominal computed tomography (CT) scan after every 10 infusions. Hepatic perfusion was checked by CT arteriography via the infusion port after every 10 infusions.

RESULTS

Radiological placements of catheters were performed successfully in all cases. Each patient received an average of 36 treatments (range: 10-98). Catheter failure was found in 3 patients (7.1%). Nine incidents of grade 1 toxicity were observed in 8 patients (19.0%). There was a complete response in 6 patients, partial remission in 18, stable disease in 9, and progression of disease in 9 (response rate: 57.1%). Overall median survival time was 29.1 months. Using Cox's proportional hazard model, lymph node metastases in primary colorectal carcinoma and pre-treatment serum CEA affected overall survival (P=0.011, P=0.005).

CONCLUSIONS

HAI after radiological placement of infusion catheters is a safe and effective treatment particularly for patients with no lymph node metastasis in primary carcinoma or with a low pre-treatment serum CEA level.

Leaky phenotype of X-linked agammaglobulinaemia in a Japanese family

X-linked agammaglobulinaemia (XLA) is an inherited immunodeficiency that is caused by a block in early B-cell differentiation. Whereas early B precursors in the bone marrow are present in substantial numbers, XLA-affected individuals have dramatically reduced numbers of circulating mature B cells, plasma cells and immunoglobulins of all isotypes. We report on a Japanese family with 3 XLA patients, in whom the serum immunoglobulin levels and number of B cells showed a significant difference among them in spite of harbouring the same splice donor site mutation in the BTK gene. We developed concise method for detection of this mutation, which is helpful for discovering the carrier. Patient 2 showed a significant serum immunoglobulin levels of all isotypes, including allergen-specific IgE. Expression of a normal and truncated size BTK gene was detected in patient 2's peripheral blood mononuclear cells (PBMCs). Expression of BTK protein was also detected in some B cells. These results suggest that the leaky phenotype in patient 2 was caused in part by the expression of a normal BTK gene transcript. The increased frequency of infection with age expanded the number of B cells with normal BTK gene expression and produced the serum immunoglobulin, including IgE.

Effects of high-dose troglitaz one on insulin sensitivity and beta-cell function in Watanabe heritable hyperlipidemic rabbits

To clarify the dose-response effects of troglitazone on insulin sensitivity and beta-cell function, we examined the effects of high-dose troglitazone (100 mg/day per animal, administered as a food admixture) on glucose and insulin metabolism in hyperinsulinemic Watanabe heritable hyperlipidemic (WHHL) rabbits, and compared the results with our previous results with low-dose troglitazone (10 mg /day per animal).

MATERIALS AND METHODS

Glucose and insulin metabolism were quantitatively characterized by a minimal model technique as reported previously.

RESULTS

When troglitazone was administrated at a high dose for 6 months, it reduced hyperinsulinemia as reflected by a reduced basal (steady-state) insulin concentration lb and the insulin response to a glucose load, improved beta-cell function as reflected by decreased second-phase post-hepatic insulin delivery to glucose phi2, and reduced insulin resistance as reflected by increased insulin sensitivity to glucose disposal Si, without affecting glucose tolerance as reflected by an unchanged rate of glucose utilization Kg or insulin-independent glucose disposal Sg. The reductions in Ib and phi2 and the increases in Si in WHHL rabbits treated with a high dose of troglitazone were greater (p<0.05) than those observed in WHHL rabbits treated with a low dose of troglitazone, as assessed by a two-way repeated measures analysis of variance and the Wilcoxon-Mann-Whitney test.

CONCLUSION

In WHHL rabbits, troglitazone dose-dependently reduced hyperinsulinemia, improved beta-cell function, and increased insulin sensitivity.

Differential susceptibility of resting CD4(+) T lymphocytes to a T-tropic and a macrophage (M)-tropic human immunodeficiency virus type 1 is associated with their surface expression of CD38 molecules

Recent evidence has accumulated which definitively shows that chemokine receptors CCR5 and CXCR4 play an essential role as coreceptors for human immunodeficiency virus type 1 (HIV-1) infection. Flow cytometric analysis permitted us to detect CD38, a surface marker of early differentiation, as well as activation of T cells, on about half of healthy donor-derived CD4(+) T cells. In this study, we focused on the susceptibility of CD38(+) and CD38(-) subsets of CD4(+) T cells to HIV-1 infection with different coreceptor tropisms. About 20% of peripheral blood mononuclear cell-derived resting CD4(+) T cells were recovered into the CD38(+) subset fraction by panning with a monoclonal antibody to CD38. Most of the cells in this CD38(high) fraction also expressed CD45RA and CD62L at higher intensities compared with those of CD38(low) fraction. CCR5(+) T cells predominated in the CD38(-) subset, although cell surface expression of CD4 and CXCR4 was almost similar between both subsets. This difference was consistent with a significantly higher susceptibility of the CD38(-) subset to a macrophage (M)-tropic HIV-1 strain. In contrast, it was shown that a T-tropic strain of HIV-1 could replicate more efficiently in the CD38(+) subset, although viral adsorption rates were similar between both subsets. Thus, the differential susceptibility of CD4(+) T cells to M(-) and T-tropic HIV-1 was associated with their surface expression of CD38.

Positive and negative aspects of the human immunodeficiency virus protease: development of inhibitors versus its role in AIDS pathogenesis

In this review we summarize multiple aspects of the human immunodeficiency virus (HIV) protease from both structural and functional viewpoints. After an introductory overview, we provide an up-to-date status report on protease inhibitors (PI). This proceeds from a discussion of PI structural design, to how PI are optimally utilized in highly active antiretroviral triple therapy (one PI along with two reverse transcriptase inhibitors), the emergence of PI resistance, and the natural role of secretory leukocyte PI. Then we switch to another focus: the interaction of HIV protease with other genes in acute and persistent infection, which in turn may have an effect on AIDS pathogenesis. We conclude with a discussion on future directions in HIV treatment, involving multiple-target anti-HIV therapy, vaccine development, and novel reactivation-inhibitory reagents.

Effect of troglitazone on exocrine pancreas in rats with streptozotocin-induced diabetes mellitus

Abnormality of pancreatic exocrine secretion has been observed in patients with diabetes mellitus. Troglitazone is a novel insulin-sensitizing agent that improves hyperglycemia and hyperinsulinemia in insulin-resistant diabetes mellitus. We investigated the effect of troglitazone on exocrine pancreas in streptozotocin (STZ)-induced diabetic rats. Diabetes mellitus was induced by intraperitoneal injection of STZ (25 mg/kg), and then 0.2% troglitazone containing rat chow was given for 2 weeks. Control diabetic animals received normal rat chow for 2 weeks. Glucose tolerance tests were performed before and after the administration of troglitazone. Pancreas weight, enzyme, protein, and insulin contents in the pancreas were measured. For the exocrine secretory study, pure pancreatic juice was collected hourly. Plasma glucose concentrations stimulated by the oral administration of 2.5 g/kg glucose in the troglitazone-treated group were significantly lower than those in the control group, but not plasma insulin concentrations. Pancreas weight in diabetic rats was less than that in normal rats. Administration of troglitazone resulted in a significant increase in pancreas weight and amylase and trypsin output. However, protein and insulin contents were not affected by the treatment with troglitazone. Both basal and cholecystokinin (CCK-8; 26 pmol/kg/h) stimulated exocrine secretion in juice volume, amylase, and trypsin output were markedly decreased in diabetic rats, compared with those in normal rats. Impaired basal and CCK-stimulated pancreatic exocrine secretion in diabetic rats recovered to the normal levels when troglitazone was given. In conclusion, troglitazone might be effective to restore exocrine pancreatic insufficiency in STZ-diabetic rats.

Troglitazone and related compounds: therapeutic potential beyond diabetes

Troglitazone and structurally related compounds (pioglitazone, rosiglitazone etc.) containing thiazolidinediones (TZD) are a novel class of antidiabetic agents which decrease blood glucose in diabetic animal models and in patients with Non-Insulin-Dependent Diabetes Mellitus (NIDDM) through alleviating insulin resistance. A large body of evidence is now accumulating indicating that insulin resistance and/or resulting hyperinsulinemia underlie the pathogenesis of not only diabetes but also of the clustering syndrome called "syndrome X" or "insulin resistance syndrome" which includes hypertension, dislipidemia and hypercoagulation. Therefore, TZD class of insulin sensitizers seem to have therapeutic potential to improve this clustering syndrome in addition to diabetes. Moreover, it was demonstrated that the TZD class of insulin sensitizers including troglitazone bind and activate the peroxisome proliferator-activated receptor gamma (PPARgamma), a nuclear hormone receptor. Although PPARgamma is predominantly expressed in adipose tissue, one of the target tissues for insulin, it have been subsequently found to be expressed in macrophages, vascular smooth muscle cells (VSMC), endothelial cells and several cancer cell lines. PPARgamma activation by PPARgamma agonists such as TZD class of insulin sensitizers in these cells modulates these cell functions such as the production of inflammatory cytokine by macrophages, proliferation and migration of VSMC, and growth or differentiation in cancer cells. In addition, troglitazone has potent antioxidant effect, and suppresses both L-type and receptor operated Ca2+ channel and protein kinase C. Thus since TZD class of insulin sensitizers has many kind of therapeutic effect in addition to lowering blood glucose, these agents expect to have therapeutic potential beyond diabetes.

Molecular design, synthesis, and hypoglycemic activity of a series of thiazolidine-2,4-diones

A series of imidazopyridine thiazolidine-2,4-diones were designed and synthesized from their corresponding pyridines. These compounds represent conformationally restricted analogues of the novel hypoglycemic compound rosiglitazone (5). The series was evaluated for its effect on insulin-induced 3T3-L1 adipocyte differentiation in vitro and its hypoglycemic activity in the genetically diabetic KK mouse in vivo. The structure-activity relationships are discussed. On the basis of the in vivo potency, 5-[4-(5-methoxy-3-methyl-3H-imidazo[4, 5-b]pyridin-2-ylmethoxy)benzyl]thiazolidine-2,4-dione (19a) was selected as the candidate for further studies in a clinical setting.

Troglitazone and emerging glitazones: new avenues for potential therapeutic benefits beyond glycemic control

Insulin resistance is characterized as one of the major pathogeneses of type 2 diabetes and has been associated with these same cardiovascular risk factors. Troglitazone, rosiglitazone, and pioglitazone are a new class of oral antidiabetic agents which can ameliorate peripheral insulin resistance in type 2 diabetes. There is considerable evidence that trogliterazone may have beneficial effects on cardiovascular and metabolic abnormalities associated with insulin resistance. There is supportive evidence for positive effects of the other glitazones, but they have been less well studied. These potential benefits span effects ranging from molecular events in the arterial wall to amelioration and/or improvement in lipid parameters known to be associated with atherosclerosis.

A thiazolidinedione improves in vivo insulin action on skeletal muscle glycogen synthase in insulin-resistant monkeys

Thiazolidinediones (TZD) have been shown to have anti-diabetic effects including the ability to decrease fasting hyperglycemia and hyperinsulinemia, increase insulin-mediated glucose disposal rate (M) and decrease hepatic glucose production, but the mechanisms of action are not well established. To determine whether a TZD (R-102380, Sankyo Company Ltd., Tokyo, Japan) could improve insulin action on skeletal muscle glycogen synthase (GS), the rate-limiting enzyme in glycogen synthesis, 4 insulin-resistant obese monkeys were given 1 mg/kg/day R-102380 p.o. for a 6-week period. Skeletal muscle GS activity and glucose 6-phosphate (G6P) content were compared between pre-dosing and dosing periods before and during the maximal insulin-stimulation of a euglycemic hyperinsulinemic clamp. Compared to pre-dosing, insulin-stimulated GS activity and G6P content were increased by this TZD: GS independent activity (p = 0.02), GS total activity (p = 0.005), GS fractional activity (p = 0.06) and G6P content (p = 0.02). The change in GS activity induced by in vivo insulin (insulin-stimulated minus basal) was also increased by this TZD: GS independent activity (p = 0.03) and GS fractional activity (p = 0.04). We conclude that the TZD R-102380 improves insulin action at the skeletal muscle in part by increasing the activity of glycogen synthase. This improvement in insulin sensitivity may be a key factor in the anti-diabetic effect of the thiazolidinedione class of agents.

Troglitazone can prevent development of type 1 diabetes induced by multiple low-dose streptozotocin in mice

Recent investigations suggest that cytotoxic cytokines such as tumor necrosis factor (TNF)alpha and interleukin (IL)-1beta or free radicals play an essential role in destruction of pancreatic beta cells in Type 1 diabetes and that, therefore, anti-oxidant or anti-TNF alpha and IL-1beta therapy could prevent the development of Type I diabetes. Troglitazone belongs to a novel class of antidiabetic agent possessing the ability to enhance insulin action provably through activating PPAR gamma and to scavenge free radicals. In the present study, we examined whether troglitazone can prevent the development of Type 1 diabetes in multiple, low-dose streptozotocin (MLDSTZ)-injected mice. In addition, effects of troglitazone on cytokine-induced pancreatic beta cell damage were examined in vitro. Type 1 diabetes was induced by MLDSTZ injection to DBA/2 mice (40 mg/kg/day for 5 days). Troglitazone was administered as a 0.2% food admixture (240 mg/kg/day) for 4 weeks from the start of or immediately after STZ injection. MLDSTZ injection elevated plasma glucose to 615 +/- 8 mg/dl 4 weeks after final STZ injection and was accompanied by infiltration of leukocytes to pancreatic islets (insulitis). Troglitazone treatment with MLDSTZ injection prevented hyperglycemia (230 +/- 30 mg/dl) and, suppressed insulitis and TNF alpha production from intraperitoneal exudate cells. TNF alpha (10 pg/ml) and IL-1beta (1 pg/ml) addition to hamster insulinoma cell line HIT-T15 for 7 days in vitro decreased insulin secretion and cell viability. Simultaneous troglitazone addition (0.03 to approximately 3 microM) significantly improved cytokine-induced decrease in insulin secretion and in cell viability. These findings suggest that troglitazone prevents the development of Type 1 diabetes in the MLDSTZ model by suppressing insulitis associated with decreasing TNF alpha production from intraperitoneal exudate cells and the subsequent TNF alpha and IL-1beta-induced beta cell damage.

Effect of troglitazone on body fat distribution in type 2 diabetic patients

OBJECTIVE

Troglitazone was recently reported to specifically promote the differentiation of pre-adipocytes into adipocytes in vitro in subcutaneous fat only, indicating a relation to insulin-resistance-improving action of troglitazone. To expand on this finding, we investigated at the clinical level how long-term administration of troglitazone influences the body fat distribution in type 2 diabetic patients.

RESEARCH DESIGN AND METHODS

Troglitazone (400 mg/day) was administered for 6 months to 30 type 2 diabetic patients whose glycemic control was poor. A total of 18 patients received diet therapy alone (in the single-treatment group, BMI 26.0 +/- 4.6, HbA1c 8.2 +/- 1.7%), and 12 patients concomitantly received glibenclamide (1.25-7.5 mg/day) (in the concomitant sulfonylurea group, BMI 25.4 +/- 4.7, HbA1c 9.2 +/- 1.2%). BMI, HbA1c, serum lipid level, and body fat distribution, which were determined by computed tomography (CT) scan at the umbilical level, were measured and compared before and after troglitazone treatment.

RESULTS

During the 6-month troglitazone treatment, HbA1c levels decreased and BMI increased in both groups. As for body fat distribution in the single-treatment group, visceral fat area (VFA) decreased (from 118.3 +/- 54.3 to 101.1 +/- 50.8 cm2; P < 0.001), and subcutaneous fat area (SFA) increased (from 189.7 +/- 93.3 to 221.6 +/- 101.6 cm2; P < 0.001), resulting in a decrease in visceral/subcutaneous (V/S) ratio (from 0.74 +/- 0.48 to 0.50 +/- 0.32; P < 0.001). In the concomitant sulfonylurea group, VFA was unchanged (from 108.1 +/- 53.5 to 112.5 +/- 59.9 cm2), while SFA increased (from 144.6 +/- 122.0 to 180.5 +/- 143.5 cm2; P < 0.01), thereby decreasing the V/S ratio (from 0.91 +/- 0.46 to 0.77 +/- 0.44; P < 0.01). The serum triglyceride level and the area under glucose curve during the 75-g oral glucose tolerance test decreased significantly in the single-treatment group.

CONCLUSIONS

According to our data, troglitazone appears to promote fat accumulation in the subcutaneous adipose tissue rather than in the visceral adipose tissue in mildly obese Japanese people with type 2 diabetes. This shift of energy accumulation from the visceral to subcutaneous adipose tissue may greatly contribute to the troglitazone-mediated amelioration of insulin resistance.

Metaphase-specific cell death in meiotic spermatocytes in mice

Apoptosis of male germ cells is a widespread but little-understood phenomenon in many animal species. The elucidation of its mechanisms could be useful in the understanding of male infertility. We have examined the distribution of dying cells with the terminal transferase-mediated nick-end labeling (TUNEL) method and by an electron-microscopic procedure in the testes of 10 mouse strains, viz., C57BL/10 (B10), SL/NiA (SL), C57BL/6 (B6), C3H/He (C3H), BALB/c (BALB), DBA2 (DBA), CBA/J (CBA), MRL/MpJ(-)+/+ (M+), MRL/MpJ-lpr/lpr (lpr), and wild-type NJL mice (Mus musculus musculus). In the testes of the B10, NJL, SL, B6, C3H, BALB, DBA, and CBA mice, very few TUNEL-positive cells are distributed in the seminiferous tubules, whereas in the testes of the M+ and lpr mice, many TUNEL-positive cells, which are restricted to stage XII seminiferous tubules, have been identified. The most important finding is that many metaphases of meiotic spermatocytes show a marked TUNEL-positive reaction. Some metaphases show apoptotic morphology electron-microscopically. These results suggest that the testes of MRL strains will provide a useful model for the study of the mechanism of metaphase-specific apoptosis in meiotic spermatocytes.

Synthesis of 2-phenylbenzofuran derivatives as testosterone 5 alpha-reductase inhibitor

A series of 2-phenylbenzofuran derivatives with a carbamoyl, alkylamino, or alkyloxy group at the 5 or 6 position of the benzofuran ring were synthesized and evaluated for rat and human testosterone 5 alpha-reductase inhibitory activities in vitro. Against rat enzyme, the carbamoyl derivatives had more potent inhibitory activities than the alkylamino or alkyloxy derivatives, and the 6-carbamoyl derivatives tended to be more potent than the 5-carbamoyl derivatives. Against human enzyme, the 6-substituted derivatives had more potent inhibitory activities than the 5-substituted derivatives. The 6-carbamoyl and 6-alkylamino derivatives tended to show stronger inhibitory activities against human type 1 enzyme than against type 2 enzyme, but they were not largely selective.

Combination treatment with troglitazone, an insulin action enhancer, and pravastatin, an inhibitor of HMG-CoA reductase, shows a synergistic effect on atherosclerosis of WHHL rabbits

We examined whether improving insulin resistance augments the antiatherosclerotic effect of LDL reduction. Since WHHL rabbits show hyperinsulinemia and insulin resistance, we administered troglitazone (100 mg/kg), an insulin action enhancer, pravastatin sodium (50 mg/kg), an HMG CoA reductase inhibitor, and a combination of both drugs to 2-month-old WHHL rabbits for 32 weeks. As compared to the control, total cholesterol levels in the plasma and LDL were decreased significantly by 20% in the pravastatin and combination groups. Basal immunoreactive insulin levels and insulin index were decreased significantly by approximately 50% in the troglitazone and combination groups. Surface lesion area of atherosclerosis on the thoracic aorta was decreased significantly by 36% in the combination group and was less in the troglitazone group. Coronary atherosclerosis was decreased significantly by 39% in the combination group and was less in the pravastatin and troglitazone groups. The collagen content in the plaques was decreased in the troglitezone and combination groups and the extracellular lipid deposits were decreased in the pravastatin and combination groups. The incidence and severity of xanthomata in the digital joints were also decreased significantly in the three treated groups. In conclusion, the antiatherogenic effect of the combination treatment is stronger than that of the monotherapy.

Inhibition of galactose-induced cataractogenesis by troglitazone, a new antidiabetic drug with an antioxidant property, in rat lens culture

Troglitazone is a new antidiabetic drug with a combined chemical structure of thiazolidinedione and alpha-tocopherol like structure (chroman ring). We evaluated the effect oftroglitazone on the morphological and biochemical changes in rat lenses cultured with galactose. Culturing in 30 mM galactose medium for 48 hrs resulted in vacuole formation in the cortex of lens equator (early phase of cataract). A significant amount of galactitol accumulation and lipid peroxide formation were also observed in lenses exposed to galactose. These morphological and biochemical changes associated with galactose were inhibited by 2 or 20 microM troglitazone present in the galactose medium. These results confirm the previous finding that troglitazone delayed the formation of cataract in rats fed a galactose diet. The anticataract effect of troglitazone was discussed in terms of antioxidant property of the drug.

Troglitazone, a new antidiabetic agent possessing radical scavenging ability, improved decreased skin blood flow in diabetic rats

Troglitazone is a new class of antidiabetic agent possessing radical scavenging ability similar to vitamin E. Because of this ability, it is expected to improve decreased nutritive capillary blood flow in diabetes. In the present study, we investigated the effects of troglitazone on skin blood flow(SBF) in normal and streptozotocin(STZ)-induced diabetic rats. Effects of troglitazone on vasodilation, PGI2 and PGE2 production were also assessed in perfused hindlimb, isolated rat aorta rings and 3T6 fibroblasts, respectively. SBF at the base of the tail was decreased in STZ diabetic rats (2.1+/-0.2 ml/min/100 g) compared with normal rats (3.8+/-0.2 ml/min/100 g). This decrease of SBF was significantly improved (2.9+/-0.2 ml/min/100 g) by troglitazone treatment (approximately 220 mg/kg/day) for 7 days in STZ diabetic rats without alleviating hyperglycemia. Similar troglitazone treatment (approximately 160 mg/kg/day for 7 days) tended to increase SBF (approximately 30%) even in normal rats. In normal rats, subcutaneous administration of troglitazone (60 mg/kg) acutely increased SBF and, this increase was suppressed by 70% with pretreatment (10 mg/kg s.c.) of indomethacin, cyclooxygenase inhibitor, suggesting that troglitazone increases skin blood flow predominantly by increasing PGI2 and PGE2 production. In hindlimb perfusion under fixed flow rate, troglitazone infusion (20 microM) significantly decreased perfusion pressure by 13%, which reflects vasodilation of blood vessels. This decrease of perfusion pressure was inhibited by concomitant infusion of indomethacin but not N-monomethyl-L-arginine, inhibitor of nitric oxide synthase. In vitro studies, using isolated rat aorta rings, revealed that troglitazone (4.5 to 45 microM) increases PGI2 production by 31 and 70%, respectively. In 3T6 fibroblast (a component of skin tissue), troglitazone at a low dose of 0.3 microM increased PGI2 and PGE2 by 200% and 25%, respectively. Overall all, these results suggest that troglitazone increases nutritive SBF probably by virtue of its radical scavenging thus the resulting in an increase in PGI2 and PGE2 production in blood vessels and fibroblast. Troglitazone may alleviate impaired microcirculation in diabetic patients through these effects.

A specific T-cell subset with CD4+/CD38- markers derived from HIV-1 carriers induces apoptosis in healthy donor-derived T-lymphocytes

Apoptosis is an important mechanism of human immunodeficiency virus type 1 (HIV-1)-induced T-cell depletion. Our recent findings revealed mitogenic stimulation-dependent apoptosis induction in healthy donor-derived peripheral blood T-lymphocytes after adsorption with defective HIV-1 particles through acquirement by a subset of CD4+/CD38- cells of specific killer function. Based on these in vitro observations, we have extended the significance of this killing activity of CD4+/CD38- cells directly derived from HIV-1 carriers. The CD4+/CD38- cells from HIV-1-positive individuals showed significantly higher cell-killing activities than those from HIV-1-negative donors by co-culture with allogeneic resting T-cells after mitogenic stimulation. Furthermore, most of the samples induced apoptosis in a Fas-dependent manner. Thus, it is suggested that HIV-1 infection-related apoptosis is triggered by inappropriate activation of a certain resting T-cell subset, presumably due to adsorption with HIV-1 particles.

Synthesis and 5 alpha-reductase inhibitory activities of benzofuran derivatives with a carbamoyl group

A series of 2-phenylbenzofuran derivatives with a diphenylmethylcarbamoyl group at the 5 or 6 position of the benzofuran ring were synthesized and evaluated for rat and human testosterone 5 alpha-reductase inhibitory activities in vitro. They had inhibitory activities against both enzymes and the 6-carbamoyl derivatives tended to be more potent than the 5-carbamoyl compounds.

Troglitazone increases the number of small adipocytes without the change of white adipose tissue mass in obese Zucker rats

Troglitazone (CS-045) is one of the thiazolidinediones that activate the peroxisome proliferator-activated receptor gamma (PPARgamma), which is expressed primarily in adipose tissues. To elucidate the mechanism by which troglitazone relieves insulin resistance in vivo, we studied its effects on the white adipose tissues of an obese animal model (obese Zucker rat). Administration of troglitazone for 15 d normalized mild hyperglycemia and marked hyperinsulinemia in these rats. Plasma triglyceride level was decreased by troglitazone in both obese and lean rats. Troglitazone did not change the total weight of white adipose tissues but increased the number of small adipocytes (< 2,500 micron2) approximately fourfold in both retroperitoneal and subcutaneous adipose tissues of obese rats. It also decreased the number of large adipocytes (> 5,000 micron2) by approximately 50%. In fact, the percentage of apoptotic nuclei was approximately 2.5-fold higher in the troglitazone-treated retroperitoneal white adipose tissue than control. Concomitantly, troglitazone normalized the expression levels of TNF-alpha which were elevated by 2- and 1.4-fold in the retroperitoneal and mesenteric white adipose tissues of the obese rats, respectively. Troglitazone also caused a dramatic decrease in the expression levels of leptin, which were increased by 4-10-fold in the white adipose tissues of obese rats. These results suggest that the primary action of troglitazone may be to increase the number of small adipocytes in white adipose tissues, presumably via PPARgamma. The increased number of small adipocytes and the decreased number of large adipocytes in white adipose tissues of troglitazone-treated obese rats appear to be an important mechanism by which increased expression levels of TNF-alpha and higher levels of plasma lipids are normalized, leading to alleviation of insulin resistance.

Compulsory superselective arterial embolization in hypovascular local hepatic tumor ablation. Microballoon coaxial catheterization

We performed compulsory superselective transcatheter arterial embolization on local hypovascular liver metastases under balloon occlusion using a 1-mm (3 F) coaxial microballoon catheter in 2 cases. One case was a metastasis from breast cancer (maximum diameter 5.5 cm) at segment 7. The other case comprised metastases from rectal cancer (maximum diameter 8 cm) at segments 7 and 8. Absolute ethanol (50%) mixed with Lipiodol (50%) was used for embolization. No major treatment-related complications occurred. No local recurrence was observed in either case in follow-up CT and MR studies of up to 16 and 9 months respectively. This technique may thus be applied as an alternative to surgical resection in the treatment of local hypovascular liver tumors.

Acute effect of troglitazone on glucose metabolism in the absence or presence of insulin in perfused rat hindlimb

Troglitazone (CS-045) is a new type of antidiabetic agent that decreases plasma glucose by enhancing insulin action in insulin-resistant diabetic animals and non-insulin-dependent diabetes mellitus (NIDDM) patients. To examine the direct effect of troglitazone on glucose metabolism and insulin action in skeletal muscle, we infused troglitazone solution into perfused rat hindlimbs in the presence of 6 mmol/L glucose and in the absence or presence of insulin. In the absence of insulin, even 50 mumol/L troglitazone did not elicit glucose uptake. Troglitazone did increase lactate and pyruvate release at concentrations of 20 mumol/L and higher; however, it decreased the ratio of lactate to pyruvate (L/P ratio) and increased oxygen consumption at concentrations higher than 5 and 20 mumol/L, respectively. In hindlimb muscle, 20 mumol/L troglitazone decreased glycogen content without changing fructose 2,6-bisphosphate (F2,6P2) content in the absence of insulin. Insulin infusion with 250 microU/mL obtained half-maximal effects, causing a 2.8-fold increase in glucose uptake and a 1.5-fold increase in lactate and pyruvate release. When 20 mumol/L troglitazone was infused for 30 minutes together with 250 microU/mL insulin, insulin-induced glucose uptake significantly increased 30 minutes after troglitazone infusion, and this increase was further augmented after withdrawal of troglitazone. In insulin plus troglitazone infusion at 30 minutes after troglitazone removal, glycogen content in hindlimb muscle was significantly decreased compared with that obtained with insulin infusion alone. In summary, in the absence of insulin, troglitazone does not elicit glucose uptake, but causes an increase in glycolysis accompanied by a decrease in muscle glycogen content and L/P ratio and an increase in oxygen consumption. In the presence of insulin, troglitazone increases insulin-induced glucose uptake, and this increase is further augmented after troglitazone removal. Addition of troglitazone to insulin infusion decreased the glycogen content in hindlimb muscle. This decrease in muscle glycogen content may trigger an enhancement of insulin-induced glucose uptake similar to that observed during muscle contraction or epinephrine treatment.

Water fraction of lumbar vertebral bone marrow estimated from chemical shift misregistration on MR imaging: normal variations with age and sex

OBJECTIVE

Our objective was to use the chemical-shift misregistration effect of MR imaging to measure the variation in the water fraction in vertebral bone marrow with respect to patient age and sex.

SUBJECTS AND METHODS

We examined prospectively 211 subjects (5-84 years old; 108 male and 103 female subjects) who had no history of hematologic disorders. We obtained midsagittal proton density-weighted spin-echo images (2500/22 [TR/TE]) with a narrow sampling bandwidth (6250 Hz). Misregistered signals from lipid protons of 6-10 mm (upward shift in the readout direction) were obtained with the chemical-shift effect. By measuring the mean signal intensities of the water voxels and the water-plus-lipid voxels, we calculated a region of interest in each vertebral body for L1 to L3. The water fraction of bone marrow was then calculated as 100 x (signal intensity of water voxels/signal intensity of water-plus-lipid voxels). Individual water fractions were calculated from the average values for the water fractions of the L1-L3 bodies.

RESULTS

In the male subjects, the water fraction showed a rapid decrease in the older patients in the 5- to 34-year-old group. (Mean water fractions for male patients who were 5-14, 15-24, and 25-34 years old were 75.2%, 69.0%, and 53.7%, respectively.) For male patients more than 25 years old, the water fraction remained almost constant (approximately 50%). In female subjects who were 5-44 years old, the water fraction exceeded 69% and remained almost constant. However, the water fraction rapidly decreased in women more than 45 years old. (Mean water fractions for female patients who were 35-44, 45-54, and 55-64 years old were 70.9%, 61.1%, and 49.7%, respectively.) A comparison between male subjects and female subjects showed that the water fraction for women who were 25-54 years old exceeded the water fraction for men in the same age group (25-34 years old, p < .0001; 35-44 years old, p < .001; 45-54 years old, p < .05).

CONCLUSION

MR imaging showed that male and female subjects convert hematopoietic marrow to fatty marrow in the lumbar vertebral bodies in significantly different ways. The data obtained for the normal water fraction of bone marrow may prove useful for evaluating diseases that affect marrow.

Medical image transmission via communication satellite: evaluation of ultrasonographic images

As compared with terrestrial circuits, communication satellites possess superior characteristics such as wide area coverage, broadcasting functions, high capacity, and resistance to disasters. Utilizing the narrow band channel (64 kbps) of the stationary communication satellite JCSAT1 located at an altitude of 36,000 km above the equator, we investigated satelliterelayed dynamic medical images transmitted by video signals, using hepatic ultrasonography as a model. We conclude that the "variable playing speed transmission scheme" proposed by us is effective for the transmission of dynamic images in the narrow band channel. This promises to permit diverse utilization and applications for purposes such as the transmission of other types of ultrasonic images as well as remotely directed medical diagnosis and treatment.

Inhibition of oxidation of low density lipoprotein by troglitazone

The effect of a new oral hypoglycemic agent troglitazone, (+/-)-5-[4-(6-hydroxy-2,5,7,8-tetramethylchroman-2-yl-methoxy)benz yl]-2,4-thiazolidinedione as an antioxidant against the free radical-mediated oxidation of low density lipoprotein (LDL) was studied. The oxidation of LDL gives cholesteryl ester hydroperoxide and phosphatidylcholine hydroperoxide as major primary products. Troglitazone incorporated exogenously into LDL inhibited the oxidations of LDL induced by either aqueous or lipophilic peroxyl radicals and suppressed the formation of lipid hydroperoxides efficiently. Ascorbic acid added into the aqueous phase spared both endogenous alpha-tocopherol and troglitazone in LDL. It was also found by absorption spectroscopic and electron spin resonance (ESR) studies that troglitazone reacted rapidly with a galvinoxyl radical to give a chromanoxyl radical which gives the same ESR spectrum as alpha-tocopherol. This ESR spectrum disappeared rapidly when ascorbic acid was added into the system. These results show that troglitazone acts as a potent antioxidant and protects LDL from oxidative modification.

Tumor necrosis factor-alpha- and hyperglycemia-induced insulin resistance. Evidence for different mechanisms and different effects on insulin signaling

Inhibition of insulin receptor signaling by high glucose levels and by TNF-alpha was recently observed in different cell systems. The aim of the present study was to characterize the mechanism of TNF-alpha-induced insulin receptor inhibition and to compare the consequences of TNF-alpha- and hyperglycemia-induced insulin receptor inhibition for signal transduction downstream from the IR. TNF-alpha (0.5-10 nM) and high glucose (25 mM) showed similar rapid kinetics of inhibition (5-10 min, > 50%) of insulin receptor autophosphorylation in NIH3T3 cells overexpressing the human insulin receptor. TNF-alpha effects were completely prevented by the phosphotyrosine phosphatase (PTPase) inhibitors orthovanadate (40 microM) and phenylarsenoxide (35 microM), but they were unaffected by the protein kinase C (PKC) inhibitor H7 (0.1 mM), the phosphatidylinositol-3 kinase inhibitor wortmannin (5 microM), and the thiazolidindione troglitazone (CS045) (2 microgram/ml). In contrast, glucose effects were prevented by PKC inhibitors and CS045 but unaffected by PTPase inhibitors and wortmannin. To assess effects on downstream signaling, tyrosine phosphorylation of the following substrate proteins of the insulin receptor was determined: insulin receptor substrate-1, the coupling protein Shc, focal adhesion kinase (FAK125), and unidentified proteins of 130 kD, 60 kD. Hyperglycemia (25 mM glucose) and TNF-alpha showed analogous (> 50% inhibition) effects on tyrosine phosphorylation of insulin receptor substrate-1, Shc, p60, and p44, whereas opposite effects were observed for tyrosine phosphorylation of FAK125, which is dephosphorylated after insulin stimulation. Whereas TNF-alpha did not prevent insulin-induced dephosphorylation of FAK125, 25 mM glucose blocked this insulin effect completely. In summary, the data suggest that TNF-alpha and high glucose modulate insulin receptor-signaling through different mechanisms: (a) TNF-alpha modulates insulin receptor signals by PTPase activation, whereas glucose acts through activation of PKC. (b) Differences in modulation of the insulin receptor signaling cascade are found with TNF-alpha and high glucose: Hyperglycemia-induced insulin receptor inhibition blocks both insulin receptor-dependent tyrosine phosphorylation and dephosphorylation of insulin receptor substrate proteins. In contrast, TNF-alpha blocks only substrate phosphorylation, and it does not block insulin-induced substrate dephosphorylation. The different effects on FAK125 regulation allow the speculation that long-term cell effects related to FAK125 activity might develop in a different way in hyperglycemia- and TNF-alpha-dependent insulin resistance.

Synthesis and testosterone 5 alpha-reductase-inhibitory activity of 4-aza-5 alpha-androstane-17-carboxamide compound with an aromatic moiety in the C-17 carbamoyl group

A series of 4-aza-5 alpha-androstane compounds with one or two aromatic moieties in the carbamoyl group at the C-17 position were synthesized and their inhibitory activities for rat and human prostatic testosterone 5 alpha-reductase were tested in vitro. Compounds with one aromatic moiety in the carbamoyl group showed high inhibitory activity for rat 5 alpha-reductase, but little for human prostatic 5 alpha-reductase. On the other hand, compounds with two aromatic moieties had potent inhibitory activities for both rat and human 5 alpha-reductase. The structural requirements for potent inhibition for both enzymes are discussed in relation to the spatial arrangement of the C-17 carbamoyl group.