Recurrent bilateral adrenal infarction with myelodysplastic/myeloproliferative neoplasm-unclassifiable (MDS/MPN-U): a case report

BACKGROUND

Bilateral adrenal infarction is rare and only a small number of cases have been reported so far. Adrenal infarction is usually caused by thrombophilia or a hypercoagulable state, such as antiphospholipid antibody syndrome, pregnancy, and coronavirus disease 2019. However, adrenal infarction with myelodysplastic/myeloproliferative neoplasm (MDS/MPN) has not been reported.

CASE PRESENTATION

An 81-year-old man with a sudden severe bilateral backache presented to our hospital. Contrast-enhanced computed tomography (CT) led to the diagnosis of bilateral adrenal infarction. Previously reported causes of adrenal infarction were all excluded and a diagnosis of MDS/MPN-unclassifiable (MDS/MPN-U) was reached, which was considered to be attributed to adrenal infarction. He developed a relapse of bilateral adrenal infarction, and aspirin administration was initiated. Partial primary adrenal insufficiency was suspected as the serum adrenocorticotropic hormone level was persistently high after the second bilateral adrenal infarction.

CONCLUSION

This is the first case of bilateral adrenal infarction with MDS/MPN-U encountered. MDS/MPN has the clinical characteristics of MPN. It is reasonable to assume that MDS/MPN-U may have influenced bilateral adrenal infarction development, considering the absence of thrombosis history and a current comorbid hypercoagulable disease. This is also the first case of recurrent bilateral adrenal infarction. It is important to carefully investigate the underlying cause of adrenal infarction once adrenal infarction is diagnosed, as well as to assess adrenocortical function.

A Novel Pathogenic MEN1 Gene Variant Identified in a Family With Multiple Pancreatic Neuroendocrine Tumors

Multiple endocrine neoplasia type 1 (MEN1) is a hereditary endocrine tumor syndrome caused by pathogenic variants in the MEN1 gene, and most patients with this syndrome initially develop primary hyperparathyroidism (PHPT). Here, we report the case of a family wherein a germline MEN1 variant was detected and multiple pancreatic neuroendocrine tumors (PanNETs) were observed at the initial evaluation. A 40-year-old woman presented with a complaint of abdominal discomfort, and a close examination revealed multiple pancreatic tumors. Distal pancreatectomy with splenectomy was performed, and the diagnosis was nonfunctional PanNETs. Five years later, her 76-year-old mother was referred to the hospital with multiple pancreatic tumors. A genetic test revealed that both patients harbored a previously unreported germline variant in the MEN1 gene. Although it was classified as a variant of uncertain significance, we suspect that it may be associated with the pathogenesis of these lesions. This case report presents a new disease concept-familial isolated pancreatic neuroendocrine tumors, or FIPNETs-in patients harboring a pathogenic variant in the MEN1 gene who experience only pancreatic lesions. We suggest that clinicians consider genetic testing for the MEN1 gene in patients with multiple pancreatic lesions who show no signs of PHPT.

Association between aldosterone and hypertension among patients with overt and subclinical hypercortisolism

Introduction

Hypertension is one of the most common clinical features of patients with overt and subclinical hypercortisolism. Although previous studies have shown the coexistence of autonomous cortisol and aldosterone secretion, it is unclear whether aldosterone plays a role in hypertension among patients with hypercortisolism. Therefore, we examined the associations of plasma aldosterone concentrations (PAC) with hypertension among patients with overt and subclinical hypercortisolism.

Methods

This single-center retrospective cohort study included patients with adrenal tumor and serum cortisol levels after 1-mg dexamethasone suppression test >1.8 µg/dL (50 nmol/L). Using multivariable regression models adjusting for baseline characteristics, we investigated the association of PAC with systolic blood pressure and post-operative improvement of hypertension after the adrenalectomy.

Results

Among 89 patients enrolled in this study (median age: 51 years), 21 showed clinical signs of Cushing’s syndrome (overt hypercortisolism) and 68 did not show clinical presentations (subclinical hypercortisolism). We found that higher PAC was significantly associated with elevated systolic blood pressure among patients with subclinical hypercortisolism (adjusted difference [95%CI] = + 0.59 [0.19-0.99], p = 0.008) but not among those with overt hypercortisolism. Among 33 patients with subclinical hypercortisolism and hypertension who underwent adrenalectomy, the postoperative improvement of hypertension was significantly associated with higher PAC at baseline (adjusted risk difference [95%CI] = + 1.45% [0.35-2.55], p-value = 0.01).

Conclusions

These findings indicate that aldosterone may contribute to hypertension among patients with subclinical hypercortisolism. Further multi-institutional and population-based studies are required to validate our findings and examine the clinical effectiveness of the intervention targeting aldosterone for such patients.

Two Cases of Thyrotoxicosis and Euglycemic Diabetic Ketoacidosis Under Sodium-glucose Transport Protein 2 Inhibitor Treatment

Thyrotoxicosis and sodium-glucose transport protein 2 inhibitors (SGLT2is) are associated with the induction of euglycemic diabetic ketoacidosis (euDKA). We herein report two cases of euDKA in patients with diabetes mellitus wherein both thyrotoxicosis and SGLT2i treatment were the underlying causes. One patient developed thyrotoxicosis during the course of type 2 diabetes mellitus, whereas the other patient was suspected of developing slowly progressive insulin-dependent diabetes mellitus during the course of Graves' disease. Although such cases are rare, there is some concern that similar cases may occur because of the increased frequency of SGLT2i use in recent years.

Successful prednisolone or calcimimetic treatment of acquired hypocalciuric hypercalcemia caused by biased allosteric CaSR autoantibodies

Biased agonism is a frontier field in G-protein coupled receptor (GPCR) research. Acquired hypocalciuric hypercalcemia (AHH) is a rare disease caused by calcium-sensing receptor (CaSR) autoantibodies, to date, showing either simple blocking or biased properties (i.e., stimulatory or blocking effects on different downstream signaling pathways). This emphasizes the importance of the Gi/o (pertussis toxin-sensitive G proteins, whose βγ subunits activate multiple signals including ERK1/2) in regulating PTH secretion. We here describe three patients with symptomatic AHH that shared characteristics with the two cases we previously reported as follows: [1] aged (between 74-87 years at diagnosis); [2] male; [3] unexpectedly showed no other autoimmune diseases; [4] showed spontaneously fluctuating calcium levels from approximately normal to near fatally high ranges; [5] acute exacerbations could be successfully treated with prednisolone and/or calcimimetics; [6] the presence of CaSR autoantibodies that operated as biased allosteric modulators of CaSR; and that [7] were likely to be conformational (i.e., recognizing and thereby stabilizing a unique active conformation of CaSR that activates Gq/11, activating phosphatidylinositol turnover, but not Gi/o). Our observations with these prominent commonalities may provide new insights into the phenotype and characteristics of AHH and the mechanisms by which the biased agonism of GPCRs operate.

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.

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.

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.

Bone marrow cellularity: quantification by chemical-shift misregistration in magnetic resonance imaging and comparison with histomorphometrical techniques

The accuracy of a technique that uses chemical-shift misregistration in magnetic resonance (MR) imaging to quantify vertebral bone marrow cellularity was tested on cadaveric specimens. In order to estimate the cellularity of 11 unfixed vertebral bodies, mid-sagittal MR images were obtained using a 1.5T magnet with a proton-density-weighted spin-echo sequence (repetition time/echo time, 2500/22 ms) and a narrow bandwidth. These values were subsequently compared to the histomorphometrical values for cellularity, amount of trabecular bone and deposited iron. The image-derived values for cellularity (VI, %) correlated well with values determined by histomorphometry (VH, %) (VI = 21.2 + 0.72 VH, r = 0.92) regardless of the presence of trabecular bone and small amount of stored iron in the specimens. This simple technique may be applicable in the estimation of marrow cellularity.

Differential diagnosis of renal lesions with US-angiography using intra-arterial CO2 microbubbles

To differentiate renal masses, 58 patients with renal masses (39 men and 19 women, aged 23-81 years [mean age 60 years]) underwent US-angiography with intra-arterial infusion of carbon dioxide (CO2) microbubbles during conventional angiography; 32 patients had renal cell carcinomas; nine, transitional cell carcinomas; nine, renal complicated cysts; four, angiomyolipomas; two, acute focal bacterial nephritis and hematomas. Renal masses were classified into six enhancement patterns of US-angiography. Thirty-one (97%) renal cell carcinomas were histologically alveolar type and demonstrated the well-enhancement pattern. All nine renal complicated cysts showed the non-enhancement pattern. Although transitional cell carcinomas did not show definite neovascularity on conventional angiography, they were classified as the well-enhancement pattern in 4/9 (44%) and poor-enhancement pattern in 5/9 (56%) on US-angiography. Four angiomyolipomas were homogeneously enhanced. Complicated cysts were clearly differentiated from renal cell carcinomas by the enhancement pattern on US-angiography. But the differentiation between renal cell carcinomas and angiomyolipomas was difficult. US-angiography is useful for detecting fine neovascularity of renal lesions and also for the differentiation or renal cell carcinomas from complicated cysts or transitional cell carcinomas during conventional angiography.

Acute hyperglycemia provides an insulin-independent inducer for GLUT4 translocation in C2C12 myotubes and rat skeletal muscle

GLUT4 translocation and activation of glucose uptake in skeletal muscle can be induced by both physiological (i.e., insulin, nerve stimulation, or exercise) and pharmacological (i.e., phorbol ester) means. Recently, we demonstrated that high glucose levels may mimic the effects of phorbol esters on protein kinase C (PKC) and insulin receptor function (J Biol Chem 269:3381-3386, 1994). In this study, we tested whether the previously described effects of phorbol esters on translocation of GLUT4 in myotubes in culture and also in rat skeletal muscle might be mimicked by glucose. We found that stimulation of C2C12 myotubes with both insulin (10(-7) mol/l, 5 min) and glucose (25 mmol/l, 10 min) induces a comparable increase of the GLUT4 content in the plasma membrane. To test whether this effect occurs in intact rat skeletal muscle as well, two different model systems were used. As an in vitro model, isolated rat hindlimbs were perfused for 80 min with medium containing 6 mmol/l glucose +/- insulin (1.6 x 10(-9) mmol/l, 40 min) or 25 mmol/l glucose. As an in vivo model, acute hyperglycemia (> 11 mmol/l glucose, 20 min) was induced in Wistar rats by intraperitoneal injection of glucose under simultaneous suppression of the endogenous insulin release by injection of somatostatin. In both models, subcellular fractions were prepared from hindlimb skeletal muscle, and plasma membranes were characterized by the enrichment of the marker enzyme alpha 1 Na(+)-K(+)-ATPase.(ABSTRACT TRUNCATED AT 250 WORDS)

Suppression of hepatic gluconeogenesis in long-term Troglitazone treated diabetic KK and C57BL/KsJ-db/db mice

The orally effective antidiabetic agent Troglitazone (CS-045) exerts hypoglycemic effects in various insulin-resistant obese and/or diabetic animals. Since increased hepatic gluconeogenesis is a major cause of hyperglycemia in these diabetic animals, we evaluated the effect of long-term Troglitazone treatment on hepatic gluconeogenesis. Troglitazone was administered for 7 days to normal ddY mice, diabetic KK mice, diabetic C57BL/KsJ-db/db mice, and its heterozygote, db/+ mice, as a 0.1% or 0.2% food admixture. Troglitazone significantly decreased plasma glucose in diabetic KK and db/db mice, but not in normal ddY and db/+ mice. 14C incorporation into blood glucose from NaH14CO3 was measured to assess hepatic gluconeogenesis in diabetic KK and normal ddY mice. Hepatic gluconeogenesis was significantly increased in diabetic KK mice (P < .01) as compared with normal mice, and was significantly suppressed (P < .05) after 7 days of Troglitazone treatment (approximately 200 mg/kg/d). Glucose-6-phosphate (G6P) and fructose-6-phosphate (F6P) were significantly decreased but fructose-1,6-bisphosphate (FBP) was not significantly increased in the liver of diabetic db/db mice treated with Troglitazone for 7 days (approximately 80 mg/kg/d) as compared with control db/db mice. These changes in G6P, F6P, and FBP corresponded with the activity of fructose-1,6-bisphosphatase (Fru-1,6P2ase) and 6-phosphofructo-1-kinase (6-PF-1K), which determined the content of F6P and FBP. Namely, Fru-1,6P2ase was significantly decreased in Troglitazone-treated db/db mice as compared with control mice, whereas 6-PF-1K activity was not affected by Troglitazone treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Differentiation between hemangiomas and hepatocellular carcinomas with the apparent diffusion coefficient calculated from turboFLASH MR images

Serial turboFLASH (fast low-angle shot) images with and without diffusion-perfusion (DP) gradients were used for the evaluation of and differentiation between hemangiomas and hepatocellular carcinomas (HCCs) of the liver. Twenty-six patients with 27 hemangiomas, and 19 patients with 21 HCCs were studied. T1- and T2-weighted spin-echo images, serial turboFLASH images with and without DP gradients (b = 294.8 and 0 sec/mm2, respectively) were obtained, and the apparent diffusion coefficient (ADC) was calculated for all lesions. Hemangiomas were detected as well-defined areas of decreased signal intensity on turboFLASH images obtained with DP gradients; HCCs showed slight or no obvious decrease in signal intensity on serial turboFLASH images obtained with DP gradients compared with turboFLASH images obtained without DP gradients, while a considerable percentage (76.5%) of nodular HCCs showed an obvious decrease in signal intensity at the margins. Hemangiomas had large ADC values compared with HCCs. Both ADC and T2 values were significantly different between hemangiomas and HCCs (P < .01). However, there was no obvious correlation between ADC and T2 values for either hemangiomas or HCCs (r = .18 and .48, respectively). On the basis of these results, the calculated ADC should be helpful for distinguishing hemangiomas from HCCs, and the ADC values may be useful even when T2 values are not helpful for making the distinction.

[A case of adenomyelolipoma]

We report case of adenomyelolipoma. CT and MRI revealed a large, capsulated, septated adrenal mass with abundant fat tissue. However, enhancing components were demonstrated at the capsule and septations on angiography. On the pathological study, the capsule and septations consisted of adrenal adenoma and the tumor contained various forms of myelolipomatous tissues. These myelolipomatous tissues were classified into 4 groups. Type I: Scattering of fat cells and hematopoietic elements without coalescence. Type II: Collection of myelolipomatous tissue with unclear margin or small myelolipomatous tissue that cannot be classified as type I or III. Diameter of the lesion is less than 1 cm. Type III: Collection of myelolipomatous tissue with clear margin or replacement of cortical nodule. Diameter of the lesion is less than 1 cm. Type IV: Collection of myelolipomatous tissue. Diameter of the lesion is equal to or greater than 1 cm. We defined adenomyelolipoma as a lesion combining adrenal adenoma (or hyperplasia) and various forms of myelolipomatous tissues (type I-IV) in view of the strong relationship between adrenal adenoma (or hyperplasia) and myelolipomatous tissue.

[A pilot study with lung-cancer screening CT (LSCT) at the secondary screening for lung cancer detection]

We have developed computed tomography (CT) equipment for lung-cancer screening (named LSCT) that can be used exclusively for lung-cancer screening with spiral volumetric CT and is available on a screening car. A pilot study with LSCT was performed from November 1992 to January 1993 on 118 screenees at the secondary examination of lung-cancer screening. Scan parameters were as follows: 120 kVp, 50 mA, slice thickness 10 mm, table feed 10 mm/sec, scan time 2 sec/rotation. All the screenees were scanned under quiet respiration instead of the breath-hold technique. Under these scan parameters, LSCT images were almost free from respiratory motion artifacts even at the lung base. Continuity of the bronchial tree and vessels was well maintained in consecutive slices. Pulmonary nodules approximately 5 mm in diameter were clearly depicted. By LSCT, 43 of 118 screenees were diagnosed to need further examinations. And 33 out of 43 screenees underwent detailed examinations. Finally, 16 lung cancers were confirmed. Ten of 16 patients with lung cancer underwent surgery; nine were in stage I and one in stage IIIA. LSCT was considered to be useful in lung-cancer screening.

Effects of Troglitazone (CS-045) on insulin secretion in isolated rat pancreatic islets and HIT cells: an insulinotropic mechanism distinct from glibenclamide

In order to elucidate the direct effects of (+/-)-5-[4-(6-hydroxy-2,5,7,8-tetramethylchroman-2-yl-methoxy) benzyl]-2,4-thiazolidinedione (Troglitazone), a newly-developed oral hypoglycaemic agent, on pancreatic beta-cell function, in vitro investigation of isolated rat pancreatic islets and a hamster beta-cell line (HIT cell) were performed. Troglitazone stimulates both glucose, and glibenclamide-induced insulin release at a concentration of 10(-6) mol/l in these cells but, conversely, inhibits insulin secretion at 10(-4) mol/l. Glucose uptake in HIT cells is similarly enhanced by 10(-6) mol/l Troglitazone, but is reduced in the presence of 10(-4) mol/l Troglitazone. However, a quantitative immunoblot analysis with a specific antibody for GLUT 2 glucose transporter revealed no significant change in GLUT 2 protein in HIT cells with 10(-6) mol/l Troglitazone. Specific binding of [3H]-glibenclamide to beta-cell membranes is replaced by Troglitazone in a non-competitive manner, but 10(-6) mol/l Troglitazone failed to eliminate ATP-sensitive K++ channel activity. These results suggest that Troglitazone has a putative non-competitive binding site at, or in the vicinity of, the sulphonylurea receptor in rat pancreatic islets and HIT cells and that the dual effect of Troglitazone on insulin secretory capacity is mediated through the modulation of glucose transport activity, possibly due to the modification of intrinsic activity in glucose transporter in pancreatic beta cells by this novel agent.