Thiazolidinedione induces apoptosis and monocytic differentiation in the promyelocytic leukemia cell line HL60

Thiazolidinedione (TZD) is known to be a potent activator of peroxisome proliferator-activated receptor gamma (PPARgamma), a nuclear receptor that constitutes a heterodimer with retinoid X receptor (RXR). Since a considerable amount of PPARgamma is expressed in various hematopoietic cells, the present study was undertaken to examine the effect of TZD in the absence or presence of LG100268, an RXR-selective ligand, on a cultured promyelocytic leukemia cell line, HL60. Treatment with TZD (25-50 microM troglitazone or pioglitazone) markedly suppressed cell proliferation of HL60. A cell cycle analysis revealed that the suppressive effect of troglitazone on HL60 cell proliferations was caused by G0/G1 cell cycle arrest as well as by an apoptotic effect. Treatment with the same concentration of troglitazone also induced the monocytic differentiation of HL60 cells. The apoptotic or the differentiating effect of TZD on HL60 cells was synergistically enhanced by the combined treatment with 1 microM LG100268, while LG100268 alone neither had an apoptotic nor a differentiating effect on HL60 cells. These results suggest that these actions are mediated through the nuclear receptor system constituted by the PPARgamma: RXR heterodimer.

Dax-1 as one of the target genes of Ad4BP/SF-1

The DAX-1 (also known as AHC) gene encodes an unusual member of the nuclear hormone receptor superfamily. DAX-1 plays a critical role during gonadal and adrenal differentiation since mutations of the human DAX-1 gene cause X-linked adrenal hypoplasia congenita associated with hypogonadotropic hypogonadism. In recent studies, DAX-1 was reported to function as a transcriptional suppressor of Ad4BP/SF-1, a critical transcription factor in gonadal and adrenal differentiation. With respect to implication of Ad4BP/SF-1 in the transcriptional regulation of the DAX-1 gene, inconsistent findings have been previously reported. We investigated the upstream region of the mouse Dax-1 (also known as Ahch) gene and identified a novel Ad4/SF-1 site by transient transfection and electrophoretic mobility shift assays. In addition, immunohistochemical analyses with a specific antibody to Dax-1 indicated the presence of immunoreactive cells in steroidogenic tissues, pituitary gland, and hypothalamus. Although the distributions of Dax-1 and Ad4BP/SF-1 were very similar, they were not completely identical. The expression of Dax-1 was significantly impaired in knock-out mice of the Ftz-f1 gene, which encodes Ad4BP/ SF-1. Taken together, our findings indicate that Ad4BP/SF-1 controls the transcription of the Dax-1 gene.

A reverse-sandwich enzyme-linked immunosorbent assay for verocytotoxin 1 and 2 antibodies in human and bovine sera

A reverse-sandwich enzyme-linked immunosorbent assay (ELISA), in which an antibody is sandwiched by antigens, was established for the titration of antibodies to verocytotoxins (VT) in human and animal sera. This assay has two advantages over a conventional indirect ELISA: (i) higher specificity and sensitivity and (ii) the ability to comparably titrate antibodies from different species. The VT1 (Shiga-like toxin 1) antibody-positive rates were 5% in 202 normal adult humans and 99% in 93 normal cattle at a dairy farm. This ELISA is most suitable for seroepidemiologic studies of infections with VT-producing Escherichia coli in humans and various animal species.

Dax-1 as one of the target genes of Ad4BP/SF-1

The DAX-1 (also known as AHC) gene encodes an unusual member of the nuclear hormone receptor superfamily. DAX-1 plays a critical role during gonadal and adrenal differentiation since mutations of the human DAX-1 gene cause X-linked adrenal hypoplasia congenita associated with hypogonadotropic hypogonadism. In recent studies, DAX-1 was reported to function as a transcriptional suppressor of Ad4BP/SF-1, a critical transcription factor in gonadal and adrenal differentiation. With respect to implication of Ad4BP/SF-1 in the transcriptional regulation of the DAX-1 gene, inconsistent findings have been previously reported. We investigated the upstream region of the mouse Dax-1 (also known as Ahch) gene and identified a novel Ad4/SF-1 site by transient transfection and electrophoretic mobility shift assays. In addition, immunohistochemical analyses with a specific antibody to Dax-1 indicated the presence of immunoreactive cells in steroidogenic tissues, pituitary gland, and hypothalamus. Although the distributions of Dax-1 and Ad4BP/SF-1 were very similar, they were not completely identical. The expression of Dax-1 was significantly impaired in knock-out mice of the Ftz-f1 gene, which encodes Ad4BP/ SF-1. Taken together, our findings indicate that Ad4BP/SF-1 controls the transcription of the Dax-1 gene.

Short report: prevalence of antibodies against spotted fever, murine typhus, and Q fever rickettsiae in humans living in Zambia

The causative agents of rickettsial diseases (Rickettsia conorii, R. typhi, and Coxiella burnetii) have been reported throughout the African continent. However, there have been no reports on epidemiologic surveys of these infections in Zambia. This study was designed to clarify the prevalence of three rickettsioses in 377 humans in Zambia. The seroprevalence of antibodies against R. conorii, R. typhi, and C. burnetii was 16.7%, 5.0%, and 8.2%, respectively. The rates of antibody positivity against R. conorii and C. burnetii were higher in the eastern (23.1% and 11.8%) and western (16.8% and 7.4%) areas of Zambia than in the northern (3.0% and 3.0%) area of this country. There was little difference among the three areas in the distribution of antibodies against R. typhi. Since cattle breeding is more extensive in the western and eastern areas than in the northern area, it is thought that cattle-breeding areas are foci of R. conorii and C. burnetii infections in Zambia.

Coinfection of Spodoptera exigua and Spodoptera frugiperda cell lines with the nuclear polyhedrosis viruses of Autographa californica and Spodoptera exigua

The Autographa californica multinucleocapsid nuclear polyhedrosis virus (AcMNPV) has a broad host range among Lepidoptera. In contrast, the Spodoptera exigua MNPV (SeMNPV) can replicate efficiently only in S. exigua larvae or S. exigua-derived cell lines. In this study, we examined the coinfection of S. exigua Se301 and Spodoptera frugiperda IPLB-SF21AEII (Sf21) cell lines with SeMNPV and AcMNPV recombinant (Ac360-501beta-gal) which was constructed for expression of beta-galactosidase under control of the polyhedrin promoter. Coinfection led to the restriction as the level of late gene expression, nonoccluded virus production, and DNA replication of Ac360-501beta-gal in both Se301 and Sf21 cell lines. In contrast, Ac360-501beta-gal supported the SeMNPV replication in Sf21 cells. Occurrence of recombinants, between Ac360-501beta-gal and SeMNPV, with expanded host range was not observed in coinfected Sf21 cells. This suggests that Ac360-501beta-gal supports the SeMNPV replication through trans-activation.

Human Ad4BP/SF-1 and its related nuclear receptor

Ad4BP (or SF-1) is an essential transcriptional factor for steroidogenesis as well as for the development of the reproductive axis. We elucidated the structure of the human Ad4BP gene. The spliced variants of Ad4BP gene, ELP1 and ELP2 in mice, are unlikely to be present in humans since the analysis of the human gene revealed an in frame stop codon, 36-bp before the first ATG of Ad4BP. The promoter sequence of human Ad4BP, upstream of non-coding exon 1 was highly conserved, and E-box was also found to be essential for the transcription of human Ad4BP gene. During the process of the human Ad4BP gene cloning, we happened to obtain an Ad4BP-related gene, FTZ-F1beta which also belongs to the nuclear receptor family. We revealed cDNA structures of rat FTZ-F1beta, and found that rat has at least two types of FTZ-F1beta isoforms, which differ only by 21 amino acids length in the A/B domain. The tissue distributions of FTZ-F1beta in rat examined by RT-PCR, was found to be abundant in liver, pancreas, and gastrointestinal tracts. These results suggest that the physiological significance of FTZ-F1beta is different from that of Ad4BP.

Sleep stage and skin temperature regulation during night-sleep in winter

To clarify the thermally comfortable environment for satisfied sleep, we investigated the relationship between skin temperatures and sleep stages during night-sleep in winter, summer and autumn. Four healthy young females served as the subjects. The experiments were performed in a climate chamber under three conditions: at 13 degrees C-RH70% with futon and blanket in winter, at 20-18 degrees C-RH60% with futon and towelket in autumn and at 29 degrees C-RH70% with towelket in summer. The subjects' skin temperature on the sole was lower until about 4 hours after lights off in winter than in autumn and summer, and the percentage of st.2 was lower and st.4 was higher in winter than in autumn and summer, although the bed climate both in winter and autumn was much the same.

Novel germline mutations of the MEN1 gene in Japanese patients with multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant disorder characterized by tumors of the parathyroid glands, the pancreatic islet cells, and the anterior pituitary. Germline mutations of the MEN1 gene in three independent Japanese cases with MEN1 were analyzed. Case 1 has revealed a 2-bp (TA) insertion at nucleotide position 341 (341insTA) in exon 2, which shifts the reading frame such that the mutant protein has a completely different amino acid sequence from codon 78 to the premature stop codon at 119. In case 2, a nucleotide substitution, i.e., TAG in place of TGG, which encodes tryptophan at codon 198 was identified (nonsense mutation). These mutations were heterozygously present and have not been reported previously. Case 3 showed no mutations in the protein-coding exons and exon-intron junctions of the MEN1 gene by single-strand conformation polymorphism or direct sequencing of the polymerase chain reaction (PCR) fragments. We confirmed the finding that patients with MEN1 carry heterozygous germline mutations in the MEN1 gene, which is compatible with the idea that the MEN1 gene is a tumor suppressor gene. The reason why mutations in the coding region of the MEN1 gene could not be detected by PCR-based analysis in some of the MEN1 patients, e.g. case 3, needs to be clarified further.

Serosurvey of wild rodents for Rickettsioses (spotted fever, murine typhus and Q fever) in Java Island, Indonesia

The prevalence of antibodies against spotted fever group rickettsia (SFGR), murine typhus and Q fever were investigated in wild rats captured in Indonesia. Sera of 327 rats were collected from Jakarta and Boyolali on Java Island. The prevalences of antibodies against SFGR and murine typhus were 128 (39.1%) and 48 (14.7%), respectively. Antibodies against Q fever were not detected in these serum samples. Antibodies against SFGR were found in all species of rats (20.8-51.9%). The antibody positive rate against murine typhus in Rattus norvegicus (38.0%) was significantly higher than that in other rat species (0-4.8%, p<0.01). The antibody positive rates against SFGR and murine typhus in rats captured in Jakarta were significantly higher than those in rats captured in Boyolali (p<0.01). In this survey, all species of rats had antibodies against SFGR, indicating that the 4 species of tested rats (R. norvegicus, R. rattus, R. exulans, R. tiomanicus) were infected with SFGR and that SFGR may infest the whole of Java Island. Most of the rats that were antibody-positive against murine typhus were captured in Jakarta. Therefore, R. norvegicus and R. rattus are likely to be important hosts of murine typhus in Jakarta. The antibody-positive rates against SFGR and murine typhus in rats captured in the dry season were significantly higher than those in rats captured in the rainy season. This may coincide with the active periods of ticks and fleas in Indonesia.

Molecular basis of hypokalemic myopathy caused by 17alpha-hydroxylase/17,20-lyase deficiency

We describe a 28-year-old woman presenting with hypokalemic myopathy caused by 17alpha-hydroxylase/17,20-lyase deficiency caused by a homozygous mutation consisting of a G-to-C transition in the initiation codon in exon 1 of the CYP17 gene resulting in expression of an enzymatically inactive truncated P450c17 protein.

Subcutaneous or visceral adipose tissue expression of the PPARgamma gene is not altered in the fatty (fa/fa) Zucker rat

We cloned 537 basepairs (bp) of rat partial peroxisome proliferator-activated receptor gamma2 (PPARgamma2) cDNA and examined the effect of fasting or obesity on the expression of two isoforms of rat PPARgamma, gamma1 and gamma2, in either subcutaneous or mesenteric adipose tissue specimens using an RNase A protection assay. In Wistar rats, expression of both isoforms was dramatically reduced after 48 hours of fasting in the two fat tissue specimens. In comparing genetically obese (fa/fa) Zucker rats and lean control rats, no significant difference was observed in expression of the two isoforms in either type of adipose tissue. From these findings, we conclude that the adipose tissue level of rat PPARgamma depends on nutritional deprivation but is not closely associated with either obesity or insulin resistance in obese Zucker rats.

[Studies of childhood non-Hodgkin's lymphoma--treatment results with the CCLSG NHL 960 protocol. Children's Cancer and Leukemia Study Group (CCLSG)]

We report here on the preliminary treatment findings of a CCLSG NHL 960 study that was initiated in March 1996. In this study, 37 patients with non-Hodgkin's lymphoma were assigned to 4 different treatment groups according to disease stage and histology: (1) localized disease; (2) advanced disease, lymphoblastic type; (3) advanced disease, large cell type; and (4) advanced disease, Burkitt type. The first three groups received the modified protocols of the NHL 890 study. Groups 1 and 3 received COPADM induction therapy (CPM, VCR, PRD, ADR, and MTX). After achieving remission, Group 1 received only maintenance therapy consisting of alternate administration of 7 drugs, while Group 3 received additional intensification therapy with combination chemotherapy consisting of MTX and Ara-C, followed by a maintenance phase involving the administration of 9 drugs. Group 2 received COPADL induction therapy (CPM, VCR, PRD, ADR, and LASP) and consolidation/intensification therapies followed by a maintenance phase. Group 4 received short-term intensive COPADM polychemotherapy. Twelve patients with localized with localized disease (stage I-II) and 25 patients with advanced disease (stage III-IV) were enrolled in this study. Except for 2 patients in the advanced disease stages who died earlier in the course of the study, all patients remained in remission.

Replication of Spodoptera exigua nucleopolyhedrovirus in permissive and non-permissive lepidopteran cell lines

The Spodoptera exigua multinucleocapsid nucleopolyhedrovirus (SeMNPV) was inoculated to eight lepidopteran cell lines derived from Spodoptera exigua (Se301), Spodoptera frugiperda (SF21AEII), Spodoptera littoralis (CLS-79), Spodoptera litura (SpLi-221), Pseudaletia separata (LeSe-11), Trichoplusia ni (hi-5), Plutella xylostella (PXL/C) and Bombyx mori (BmN4). The productive infection of SeMNPV was observed only in Se301 cells. However, a dot-blot hybridization analysis revealed that SeMNPV DNA replicated in five non-permissive cell lines: SF21AEII, CLS-79, SpLi-221, hi-5 and BmN4. In addition, the virus-infected hi-5 and BmN4 cells displayed morphological changes. In contrast, CLS-79 cells inoculated with SeMNPV showed membrane blebbing at 20 hrs post inoculation (p.i.) and fragmentation of genomic DNA. All that indicated that the infected CLS-79 cells underwent apoptosis. These findings indicate that the SeMNPV replication was restricted at various points in dependence upon each cell line.

Low level of glucocorticoid receptor messenger ribonucleic acid in pituitary adenomas manifesting Cushing's disease with resistance to a high dose-dexamethasone suppression test

OBJECTIVES

The overnight 8-mg dexamethasone suppression test is often used to differentiate Cushing's disease, due to an oversecretion of ACTH from the pituitary gland, from other kinds of Cushing's syndrome. However, a few patients with ACTH-producing pituitary adenoma show no suppression of plasma cortisol after the administration of 8 mg of dexamethasone. To clarify the relationship between the level of glucocorticoid receptor (GR) in the pituitary adenoma and the sensitivity to dexamethasone in Cushing's disease, we thus examined the levels of GR alpha and GR beta mRNAs in the pituitary adenomas in six patients who were proven at surgery to have pituitary ACTH-producing adenomas.

MATERIALS

Total RNA was extracted from six pituitary adenomas and pituitary tissue adjacent to one of the adenomas, and the mRNA levels of GR alpha, GR beta, pro-opiomelanocortin (POMC) and beta-actin in these samples were sampled by quantitative RT-PCR.

RESULTS

The GR alpha mRNA levels in the adenomas from the two patients who showed no response to the 8-mg dexamethasone suppression test were significantly lower than those in the adenomas of four patients who showed suppression. The GR beta mRNA level was much lower than that of GR alpha mRNA but not significantly different among the six adenomas.

CONCLUSIONS

These results suggest strongly that decreased expression of GR alpha in pituitary adenomas may be the major reason for the marked insensitivity to the 8-mg dexamethasone suppression test observed in two patients with Cushing's disease.

Characterization of temperature rise of the brain and the rectum following intracerebroventricular administration of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate and kainate in rats

Intracerebroventricular administration of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) or kainate caused a rise of the temperature of the brain and the rectum in urethane-anesthetized rats. An AMPA-kainate receptor antagonist, 6,7-dinitroquinoxaline-2,3-dione (DNQX), significantly suppressed the AMPA- and kainate-induced rises of brain and rectal temperatures. An N-methyl-d-aspartate receptor antagonist, MK-801, also suppressed the rises of the brain and rectal temperatures induced by AMPA or kainate, but the profiles of the suppressive effects of MK-801 were different between rats treated with AMPA and kainate. An antipyretic agent, indomethacin, completely suppressed the AMPA-induced rises of brain and rectal temperatures. Although indomethacin completely suppressed the kainate-induced rise of the rectal temperature as well, the brain temperature was still raised. These findings suggest that distinct mechanisms may be involved in the temperature rise of the brain and the rectum mediated through AMPA and kainate receptor stimulation.

A rare case of 46,XX true hermaphroditism with hidden mosaicism with sex-determining region Y chromosome-bearing cells in the gonads

The sex-determining region Y chromosome (SRY) triggers testis determination. We report a 46,XX true hermaphrodite who had ambiguous genitalia at birth. A laparotomy at one year of age revealed this patient to have a testis on the right side and an ovotestis on the left side. By polymerase chain reaction analysis no SRY was detected in the DNA from the leukocytes but it was found in the DNA from the ovotestis. The hidden mosaicism with the Y-bearing cells in the gonads is likely the cause of the dual gonads in this patient.

Detection of Coxiella burnetii from dust in a barn housing dairy cattle

We attempted to detect Coxiella burnetii in dust samples collected from a barn housing dairy cattle by the polymerase chain reaction (PCR) method. Ten dust samples (five from ventilation fans and five from crossbeams) were collected from two areas in a barn on a farm near Sapporo, Hokkaido. C. burnetii was detected in 5 of the 10 dust samples. It was believed that aerial contamination by C. burnetii occurred in the barn.

Analysis of defective genomes of bombyx mori nucleopolyhedrovirus generated by serial undiluted passage in cell culture

Viral DNA was extracted from cells infected with bombyx mori nucleopolyhedrovirus (BmNPV) D1 strain after 34 serial undiluted passages (P34). P34 DNA was subjected to restriction analysis and Southern blot hybridisation using standard D1 DNA and P34 DNA of BmNPV as probes. Based on hybridisation profiles, the BmNPV DNA regions retained in the P34 DNA were localised on HindIII and PstI restriction maps. Two regions of BmNPV DNA located at 0-12.8 and 40.2-65.0 map unit (m.u.) were highly conserved in P34 DNA. These regions contained two of three interspersed homologous sequences (ihss), but only one of five homologous regions (hrs). This suggests that ihss may have an essential role in BmNPV replication.

[Treatment of children with non-Hodgkin's lymphoma with CCLSG NHL 855/890 protocols long-term outcome and incidence of secondary malignancies]

We report here on treatment results of consecutive CCLSG NHL studies (NHL855, 1985-1989; NHL890, 1989-1996). The NHL855 protocol consisted of an induction phase of five drugs (VCR, PRD, CPM, DXR, and high-dose MTX) and a maintenance phase of 7 drugs. The probabilities of EFS at 7 years were 78% (SE, 10%) for the patients with localized disease, and 38% (SE, 7%) for those with advanced disease. In the NHL 890 protocol, the patients were assigned to two different treatment groups according to their histology and received different consolidation therapy; non-lymphoblastic subtype was treated almost identically to NHL855 while LASP and VP-16 were newly added for the lymphoblastic subtype. The 7-year EFS improved to 91% (SE, 6%) for localized disease, and 61% (SE, 6%) for advanced disease. A remarkable improvement was particularly evident for lymphoblastic type with mediastinal mass. Optional trial of high-dose sequential chemotherapy and peripheral blood progenitor cell auto grafting resulted in an unfavorable outcome. The 7-year EFS according to main histological subgroups were as follows: 84% (10%) for large cell type, 67% (11%) for Burkitt's-type, 58% (10%) for lymphoblastic type. Secondary cancer occurred in two of the 163 patients studied. Both patients were AML (M0/M4) and MLL rearrangement was detected in the M4 case.

Novel mutation of the DAX1 gene in a patient with X-linked adrenal hypoplasia congenita and hypogonadotropic hypogonadism

X-linked adrenal hypoplasia congenita (AHC) is characterized by primary adrenal insufficiency and is frequently associated with hypogonadotropic hypogonadism (HHG). Mutations of the DAX1 gene have been reported in patients with AHC and HHG. We found a novel DAX1 mutation in our patient. Sequence analysis of the patient's DAX1 demonstrated a 1-bp (G) deletion at codon 49 in exon 1. The mutation shifts the reading frame, resulting in completely different amino acid sequences from codon 49 to the premature stop codon at 84. The G was present at this position in the sequences of the father and 2 younger brothers. Direct sequence and single-strand conformation polymorphism analyses of polymerase chain reaction fragments revealed that the mutation at codon 49 was heterozygously present in the mother's DAX1 gene. The codon 84 is located in the first half of the DNA binding domain, and the mutation site is closer to the N-terminus than those in previously reported cases. The onset of adrenal insufficiency in the neonatal period as seen in our patient has also been reported in other patients with different DAX1 mutations, especially in a patient with DAX1 protein lacking 11 amino acids at the C-terminus. Therefore, it is less likely that position of termination codons correlate to clinical manifestations.

Immunohistochemical study of cytochrome b5 in human adrenal gland and in adrenocortical adenomas from patients with Cushing's syndrome

Cytochrome b5, a component of the electron transfer system increases the relative activity of 17,20-lyase to 17alpha-hydroxylase of P450c17 in vitro. In the present study, immunohistochemical analysis of cytochrome b5 was performed in the human adrenal gland and in adrenocortical adenomas from patients with Cushing's syndrome. In the human adrenal gland, cytochrome b5 was stained in all three adrenocortical layers but the staining was most remarkable in the zona reticularis. All of the adenomas were composed mainly of compact cells, which exhibited immunoreactive staining for cytochrome b5 as well as for P450c17 and 3beta-hydroxysteroid dehydrogenase (3beta-HSD). The distribution of b5 in the adenomas was correlated with that of P450c17 rather than with that of 3beta-HSD. The immunoreactive staining for cytochrome b5 appeared to be more prominent in the two adenomas that produced relatively high concentrations of adrenal androgens than in adenomas that produced low concentrations of adrenal androgens. These results immunohistochemically support the functional association of b5 with androgen production through interaction with P450c17 and the previous finding that higher concentrations of cytochrome b5 are associated with greater production of adrenal androgens in adrenocortical adenomas from patients with Cushing's syndrome.

Glomerular score as a prognosticator in IgA nephropathy: its usefulness and limitation

Glomerular sclerosis, mesangial hypercellularity, extracapillary lesions, interstitial fibrosis, and vascular sclerosis have been reported to be the significant pathologic prognosticators in IgA nephropathy (IgAN). We developed our own scoring for the following main glomerular changes in 248 patients with IgAN: 1) glomerular hypercellularity (mesangial and endocapillary), 2) segmental lesions such as tuft adhesion, crescent and segmental sclerosis, 3) global glomerular sclerosis. Indices of each lesion were semiquantitatively determined. The sum of these three indices was defined to be a glomerular score. We found that a glomerular score significantly related to the outcome of patients with IgAN in univariate life table analysis. We also semiquantitatively determined total score including tubulo-interstitial and vascular lesions as well as glomerular score and compared the predictive power as a prognosticator between glomerular score and total score. Using Cox's proportional Hazard model and log-likelihood ratio test, we confirmed that predictive power of glomerular score was better than that of total score. Furthermore, we assessed the reproducibility of glomerular score using Kappa statistics. Three pathologists read 100 biopsies which were randomly selected from the materials and all pathologists read them twice. A value of Kappa between the first and second observation of pathologist A, B and C was 0.68, 0.71 and 0.60, respectively. Values of Kappa between Pathologist A and B were ranging from 0.45 to 0.47, those between Pathologist A and C from 0.30 to 0.36, and finally those between Pathologist B and C were ranging from 0.12 to 0.23. Therefore, intra-observer reproducibility was nearly excellent. And inter-observer reproducibility between Pathologist A and B was satisfactory. However, inter-observer reproducibility between Pathologist A and C and between B and C was not satisfactory. We feel our scoring system is very convenient and easy to be understood as a prognosticator in patients with IgAN. It, however, should be used by one pathologist because of excellent intra-observer reproducibility and rather unsatisfactory inter-observer reproducibility.

Acinar-islet cell carcinoma presenting as insulinoma

A case of acinar-islet cell carcinoma presenting as insulinoma is reported. The patient was a 28-year-old man who presented with two convulsive episodes. Fajans' index [immunoreactive insulin (IRI; microU/ml/ glucose mg/dl)] and Turner's [IRI (microU/ml) x 100/glucose (mg/dl) - 30] index were high (2.8 and 308, respectively), as were serum proinsulin levels (550 pg/ml). Abdominal computed tomography and angiography revealed a highly vascular tumor in the pancreatic tail and several similar tumors in the liver. Histologic features of a biopsy specimen from a hepatic tumor were those of a malignant pancreatic endocrine tumor. Insulin secretion by the liver metastases was confirmed by venous sampling after arterial stimulation with calcium. These findings led us to diagnose malignant insulinoma with liver metastases. Serum levels of alpha-fetoprotein and trypsin were markedly elevated, to 2234 ng/ml (normal < 10) and 22,000 ng/ml (normal < 460) respectively, and these levels continued to rise with further growth of the liver metastases. Immunohistochemically, the metastatic liver tumor specimen was positive for alpha-fetoprotein, alpha 1-antichymotrypsin, chromogranin A, and neuron-specific enolase. These findings of amphicrine features in the tumor were indicative of acinar-islet cell carcinoma that produced alpha-fetoprotein and trypsin in addition to insulin.

A case of mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes associated with diabetes mellitus and hypothalamo-pituitary dysfunction

A 45-year-old woman with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) had muscular atrophy, severe cerebral and cerebellar atrophy, and cardiac hypertrophy. She also had diabetes mellitus treated with insulin, and sensorineural hearing loss. Ragged-red fibers were observed on muscle biopsy and an adenine to guanine transition mutation at position 3243 of her mitochondrial DNA was confirmed. Further investigations revealed that she also had hypothalamo-pituitary dysfunction. It appears that diabetes mellitus, hypothalamo-pituitary dysfunction, and the other abnormalities are all associated with mitochondrial dysfunction in this patient.

Distinct effects of MK-801 and (+/-)-2-amino-5-phosphonopentanoic acid on N-methyl-D-aspartate-induced rise of brain temperature in rats

Intracerebroventricular (i.c.v.) administration of N-methyl-D-aspartate (NMDA) caused a biphasic rise of brain temperature, namely, a rapid, early rise and a larger, late rise, in urethane-anesthetized rats. I.c.v. pretreatment with a noncompetitive NMDA receptor antagonist, MK-801, attenuated the late rise of the brain temperature, but had no effect on the early rise, whereas i.c.v. pretreatment with a competitive NMDA receptor antagonist, (+/-)-2-amino-5-phosphonopentanoic acid (AP-5), attenuated both rises. AP-5 per se caused a rise in brain temperature without any rise of rectal temperature, whereas MK-801 per se caused no significant change of the brain or rectal temperature. This rise by AP-5 was suppressed by MK-801, suggesting an agonistic effect of AP-5 on NMDA receptors in rat brain in vivo.

[Treatment results of intermittent and cyclic regimen with ATRA and chemotherapy in childhood acute promyelocytic leukemia. Children's Cancer and Leukemia Study Group]

An intermittent and cyclic regimen with All-Trans Retinoic Acid (ATRA) and intensive chemotherapy was conducted due to pharmacokinetic studies on ATRA for acute promyelocytic leukemia (APL) in children. We have treated 17 children with APL using ATRA for remission induction followed by an intermittent schedule of ATRA plus intensive chemotherapy (APL-ATRA protocol). There were 10 males and 7 females. The median age was 9.0 years old. The median baseline white blood cell count was 12.1 x 10(3)/microliter, hemoglobin 7.8 g/dl, platelet 4.5 x 10(4) microliters at diagnosis. Sixteen patients showed t(15; 17) translocation. RT-PCR analysis was available in 15 patients and showed PML/RAR alpha rearrangement in all patients. Overall, 13 or 17 newly diagnosed patients (88%) achieved complete remission and EFS was 67%. Compared to the control (same chemotherapy without ATRA regimen), remission induction and EFS were significantly increased. The toxicity of ATRA consisted of retinoic acid syndrome in 1 and pseudotumor cerebli in another. Other toxicities included headache, chelitis, gastrointestinal trouble and bone pain. These results suggest that intermittent and cyclic regimen with ATRA and intensive chemotherapy (APL-ATRA protocol) is highly effective for APL patients.

[Recent progress in the research field of nuclear receptors]

In the research field of nuclear receptors, the studies on the protein factors which interact with the steroid hormone receptors and regulate the transcriptional activity, and on the alpha and beta isoforms of glucocorticoid receptor have been in great progress. The include "intermediary Factors" such as RIP140, TIF-1, for the AF-2 which contribute to ligand-dependent transactivation function of the receptors. ARA70 which specifically interacts with androgen receptor was also cloned recently. Informations obtained from steroid hormone receptor knockout-mice experiments can also be available for the estrogen, glucocorticoid, and progesterone receptors. Furthermore, there have been more than sixty orphan receptors identified in these eight years, including HNF, Ad4BP, DAX-1, and nur77/NGFIB, some of which are mutation target genes of human congenital diseases.

Detection of Coxiella burnetii in cow's milk by PCR-enzyme-linked immunosorbent assay combined with a novel sample preparation method

The use of an adequate concentration of Triton X-100 enhanced immunomagnetic separation of Coxiella burnetii from milk. PCR-enzyme-linked immunosorbent assay (PCR-ELISA) could detect coxiellas more sensitively than could conventional PCR. PCR-ELISA is therefore thought to be suitable for the simultaneous assay of a large number of samples. However, the number of cows from which raw milk tested positive for coxiellas by PCR-ELISA was inconsistent with that found with the antibody to coxiella by indirect immunofluorescence assay. The inconsistency is thought to be associated with the differences in the infectious route, infectious dose, or the timing of yielding the antibody and the period of duration of the antibody.

Inhibition of NMDA-induced increase in brain temperature by N-omega-nitro-L-arginine and indomethacin in rats

Intracerebroventricular administration of N-methyl-D-aspartate (NMDA) caused an increase in brain temperature, which appeared rapidly and preceded that in rectal temperature, in urethane-anesthetized rats. The increase in brain temperature was divided into two phases, an early increase and a late increase. Intracerebroventricular indomethacin, a cyclooxygenase inhibitor, completely abolished the NMDA-induced late increase, but not the early increase, in brain temperature. On the other hand, intracerebroventricular N-omega-nitro-L-arginine, a potent inhibitor of nitric oxide synthase, strongly suppressed both the early and the late increases. These findings suggest that both nitric oxide and prostaglandins may be involved in the increase in brain temperature after NMDA receptor activation.

Differential expression of PPAR gamma1 and gamma2 isoforms in human adipose tissue

One of the essential factors for adipogenesis, peroxisome proliferator activated receptor gamma (PPAR gamma), is classified into two isoforms, gamma1 and gamma2 encoded by a single PPAR gamma gene. To examine the mode of expressions of both the PPAR gamma1 and gamma2 isoforms in human adipose tissue, we cloned a partial cDNA of the human PPAR gamma2 (hPPAR gamma2) from a human adipose tissue cDNA library. The sequence encoded an additional 28 amino acids amino-terminal to the first ATG codon of hPPAR gamma1. The simultaneous quantitation of hPPAR gamma1 and gamma2 mRNA in subcutaneous or visceral (mesenteric) fat tissue from 10 different individuals was performed by an RNase protection assay and revealed a relatively higher expression of gamma1 than gamma2 in all specimens examined.

Seasonal variations in the presence of antibodies against Coxiella burnetii in dairy cattle in Hokkaido, Japan

The prevalence and seasonal variations of infection by Coxiella burnetti in cattle were investigated seroepidemiologically on a farm in Hokkaido, Japan, by an immunofluorescent antibody test. A total of 364 serum samples from 28 cows were collected from August 1993 to October 1995 in two barns on the farm. It was found that the number of antibody-positive cows and their antibody titers were significantly elevated in winter and decreased in summer. In addition, antibodies were detectable in seroconverted cows for about five months.

Overview of clinical studies of childhood acute lymphoblastic leukemia for more than ten years by the Japanese Children's Cancer and Leukemia Study Group

Since 1981, the Children's Cancer and Leukemia Study Group (CCLSG) has developed a series of protocols for treatment of acute lymphoblastic leukemia (ALL) in childhood. In the first randomized controlled study of the 811 protocol (1981-1983) a comparison of conventional daily 6-mercaptopurine and methotrexate with a pulsed regimen of the two drugs was performed. The superiority of the pulsed regimen was shown. In the next 841 protocol (1984-1987) a comparison of two drugs and three drugs during induction therapy was conducted. The three-drug regimen resulted in a significantly higher event-free survival (EFS) rate. In the 874 protocol (1987-1990) two regimens with or without cranial irradiation were randomly compared, and there was no significant difference between the two regimens for the standard-risk group. To further improve the EFS rate a risk group-directed protocol 911 was conducted starting in January 1991. Life-table analysis of serial CCLSG protocols revealed that the outcome of overall ALL has gradually improved with an increase of the EFS rate; 41.4% +/- 3.6% at 14 years for the 811 protocol, 51.3% +/- 3.5% at 11 years for the 841 protocol, 56.7% +/- 3.1% at 8 years for the 874 protocol, and 78.2% +/- 3.1% at 4 years for the more recent 911 protocol.

Mutation of cytochrome P-45017 alpha gene (CYP17) in a Japanese patient previously reported as having glucocorticoid-responsive hyperaldosteronism: with a review of Japanese patients with mutations of CYP17

A 17-yr-old female Japanese patient, who was reported in 1968 as having glucocorticoid-responsive hyperaldosteronism but was presumed to have a defect of 17 alpha-hydroxylation mainly in the adrenal glands as the etiology of her illness, was followed. The relationship between clinical manifestations and molecular abnormalities in cytochrome P-45017 alpha gene (CYP17) was also reviewed based on the literature on Japanese patients with 17 alpha-hydroxylase deficiency. She has been treated with dexamethasone, resulting in normal blood pressure and normokalemia for 28 yr. She had almost normal gonadal function with regular menstruation on her first admission. Because of sustained genital bleeding, however, she underwent total hysterectomy with an ovarian biopsy at the age of 42 yr. No follicles or corpus luteum were detected in the ovarian specimen. At the age of 45 yr, the basal levels of sex steroids were decreased, while those of gonadotropins were increased. A genetic study on CYP17 revealed a homozygous deletion of phenylalanine (Phe) codon (TTC) at either amino acid position 53 or 54 in exon 1. A review of the literature revealed 4 patients with this type of CYP17 mutation, including the present patient, out of a total of 11 young adult Japanese patients. The clinical manifestations caused by congenitally deficient gonadal function were not marked in any of these 4 patients, but were marked in 5 of the 7 patients with different mutations of CYP17. The remaining 2 female patients had irregular menstruation. The pretreatment urine/plasma values of aldosterone were variable, normal to high, in individual patients, regardless of the structural abnormalities of CYP17. The following conclusions were suggested: 1) this type of CYP17 mutation is associated with well preserved gonadal function in young adult patients, but it likely causes early reduction of gonadal function with increasing age in these patients; 2) the prevalence of this type of CYP17 mutation is quite high in Japanese patients; and 3) the pretreatment hyperaldosteronism observed in the present patient seems not to be related to the mutation of CYP17.

Dehydroepiandrosterone markedly inhibits the accumulation of cholesteryl ester in mouse macrophage J774-1 cells

To clarify the antiatherogenic mechanism of action of dehydroepiandrosterone (DHEA), we investigated the effects of DHEA on the accumulation of cholesteryl ester (CE) in cultured mouse macrophage J774-1 cells. The accumulation of CE in J774-1 cells in the presence of acetyl low density lipoprotein (AcLDL) and 10(-5) mol/l DHEA was significantly reduced to 30% of the control values for 24 h. The marked effect of DHEA was observed as early as 6 h and continued at least for 48 h. This reduction by DHEA was dose-dependent and occurred starting at a DHEA dose of 5 x 10(-7) mol/1 for 24 h. DHEA treatment did not induced any changes in the cell surface binding, cell-association, or degradation of AcLDL. In comparison, the DHEA analogues, 8354 and 8356, which are known to be much stronger inhibitors of glucose 6-phosphate dehydrogenase than DHEA, did not show as marked an effect as DHEA on the accumulation of CE during the first 6 h. However, after 24-48 h of incubation, both 8354 and 8356 caused a marked reduction in the accumulation of CE similar to that observed with DHEA. A quantitative analysis of the cellular cholesterol content revealed that DHEA caused a marked reduction in CE with a concomitant continuous increase in free cholesterol (FC), while the DHEA analogues caused a marked reduction in CE with no change in FC. DHEA demonstrated little inhibitory effect on 25-hydroxycholesterol-driven esterification. Moreover, 10(-5) mol/1 DHEA induced a CE reduction in the foam cells induced by AcLDL. The CE-reducing capacity was also observed in the DHEA analogues. This CE-reducing capacity disappeared, however, when acyl CoA:cholesterol acyltransferase inhibitor, 58-035, was also present. Based on these findings, it can be concluded that the inhibitory effect of DHEA on the CE storage in response to AcLDL can be explained, at least in part, by two mechanisms. First, a recently published mechanism, namely, the inhibitory action of DHEA on lysosomal cholesterol transport, correlates well with the inhibition against foam cell transformation by DHEA in the early phase (at 6 h) observed in our study. With regard to the second mechanism, the CE-reducing capacity of DHEA from CE-laden foam cells, which appears to be related to a decreased cholesteryl ester cycle, may contribute to the inhibitory effect on the CE storage in the late phase (at 24 h and 48 h). These phase-specific inhibitory mechanisms of DHEA on the CE-storage may therefore partly explain the antiatherogenic action of DHEA.

Structural characterization of human Ad4bp (SF-1) gene

Ad4BP (or steroidogenic factor 1, SF-1) has been implicated to be an essential transcriptional factor for steroidogenesis as well as for the development of the reproductive axis. We elucidated the structure of the human Ad4BP gene. The gene is about 30 kb long and is split into 7 exons including a non-coding exon 1. The deduced amino acid sequence of the human Ad4BP consists of 461 amino acid residues and was highly homologous to those of other mammalian species.

[Antinociceptive effects of Kami-kihi-to in mice]

Oral administration of Kami-kihi-to (KMK) dose-dependently inhibited the response to acetic acid-induced writhing in mice. The KMK-induced antinociceptive action was reduced by pretreatment with yohimbine, an alpha 2-adrenergic antagonist, or cyproheptadine, a serotonergic antagonist, but not naloxone, an opiate antagonist. The antinociceptive action of KMK was clearly reduced by pretreatment with alpha-methyl-DL-p-tyrosine, reserpine or p-chlorophenylalanine or by simultaneous treatment with diethyldithiocarbamate, all of which are monoamine synthetic inhibitors or monoamine depletors. After spinal transection, the antinociceptive effect of KMK was markedly reduced. These findings suggest that the antinociceptive action of KMK may be related to pain inhibitory systems such as the serotonergic and noradrenergic systems at the supraspinal level.

Improved method for preparation of samples for the polymerase chain reaction for detection of Coxiella burnetii in milk using immunomagnetic separation

Immunomagnetic separation (IMS) improved the detection of Coxiella burnetii in cow's milk by the polymerase chain reaction (PCR). IMS represents a novel approach to the isolation of microorganism from milk. The combination of IMS and PCR analysis has an adequate sensitivity for detection of C. burnetii.

Expression of sterol carrier protein 2 (SCP2) in human adrenocortical tissue

Sterol carrier protein 2 (SCP2) has been implicated in adrenal steroidogenesis by in vitro studies. In order to clarify the clinical significance of SCP2 in human steroidogenesis, we investigated the expression of SCP2 mRNA in various types of adrenocortical tissue and one testis and examined the correlation between the amounts of SCP2 and other values such as the free cholesterol content and the cholesterol side-chain cleavage (SCC) activity in the tissue mitochondria. The types of adrenocortical tissue examined included adrenocortical carcinomas (N = 3), adrenocortical adenomas from patients with Conn's syndrome (N = 3) and from patients with Cushing's syndrome (N = 3), non-functioning adrenocortical adenomas (N = 2) and normal adrenal glands (N = 2). Northern blot hybridization predominantly revealed a 1.8-kb SCP2 mRNA in all tissue specimens examined. The mRNA concentrations of SCP2 in two out of three adrenocortical carcinomas were relatively lower than those in other types of tissue. No other special tendency was observed regarding the mRNA expression levels in various tissue specimens. The mRNA concentrations of SCP2 correlated significantly with mitochondrial contents of free cholesterol (r = 0.67, p < 0.01), but was not correlated with the SCC activities in mitochondria measured by an in vitro enzyme assay. The mitochondrial SCC activities, however, were correlated significantly with the protein levels of mitochondrial P-450 scc determined by a Western blot analysis (r = 0.79, p < 0.01). The significant positive correlation between mRNA concentrations of SCP2 and the mitochondrial content of free cholesterol suggests that the central role of SCP2 in human steroidogenic tissues may be in part a translocation of cytoplasmic free cholesterol to the mitochondria, as demonstrated previously by in vitro studies.

Dibutyryl cAMP improves systemic vasoconstriction caused by endotoxin in dogs

We studied whether dibutyryl cyclic adenosine monophosphate (DbcAMP), which freely penetrates into the cells, improves systemic vasoconstriction caused by endotoxin in dogs. Thirteen anesthetized dogs were randomized into three groups. The endotoxin (ETX) group (n = 5) received only Escherichia coli endotoxin (3 mg.kg-1, intravenously). The ETX + DbcAMP group (n =5) received DbcAMP (6 mg.kg-1, intravenously) 30 min before the administration of endotoxin. The DbcAMP group received the same dose of DbcAMP 30 min after administration of saline. In the ETX group, systemic blood pressure and cardiac index significantly decreased, and systemic vascular resistance significantly increased, while in the ETX + DbcAMP group, increases in systemic and pulmonary vascular resistances after the administration of endotoxin were attenuated. DbcAMP did not cause hemodynamic changes in normal dogs. Plasma concentrations in thromboxane B2 in the ETX group were higher than in the ETX + DbcAMP group. Also, the change in plasma cyclic AMP concentrations showed a good logarithmic correlation with the change in plasma thromboxane B2 concentrations after the administration of endotoxin (r = .908, log (delta T x B2) = -.002* (delta cAMP) + 3.786). We conclude that DbcAMP improves systemic vasoconstriction caused by endotoxin in dogs. The beneficial mechanism of DbcAMP on systemic vasoconstriction after the administration of endotoxin may be partially due to inhibition of thromboxane B2.

Cyclic Cushing's disease in long-term remission with a daily low dose of bromocriptine

A 56-year-old male patient with cyclic Cushing's disease remained in a state of remission for more than one year with a relatively low dose of bromocriptine (2.5-3.75 mg/day). It has been reported that bromocriptine treatment for cyclic Cushing's disease induces only a transient remission; in the most effective cases, a relatively high dose (40 mg/day) was necessary. In the hypercortisolemic state, plasma adrenocorticotropic hormone (ACTH) and serum cortisol were not suppressed by dexamethasone and did not respond to corticotropin-releasing factor (CRF). An antehypophysectomy was not effective, even though the resected tissue contained ACTH-positive microadenomas. The present observations thus indicate the effectiveness of bromocriptine for some patients with this rare disorder.

New mutations of DAX-1 genes in two Japanese patients with X-linked congenital adrenal hypoplasia and hypogonadotropic hypogonadism

Congenital adrenal hypoplasia, an X-linked disorder, is characterized by primary adrenal insufficiency and frequent association with hypogonadotropic hypogonadism. The X-chromosome gene DAX-1 has been most recently identified and shown to be responsible for this disorder. We analyzed the DAX-1 genes of two unrelated Japanese patients with congenital adrenal hypoplasia and hypogonadotropic hypogonadism by using PCR amplification of genomic DNA and its complete exonic sequencing. In a family containing several affected individuals, the proband male patient had a stop codon (TGA) in place of tryptophan (TGG) at amino acid position 171. As expected, his mother was a heterozygous carrier for the mutation, whereas his father and unaffected brother did not carry this mutation. In another male patient with noncontributory family history, sequencing revealed a 1-bp (T) deletion at amino acid position 280, leading to a frame shift and, subsequently a premature stop codon at amino acid position 371. The presence of this mutation in the patients' genome was further confirmed by digestion of genomic PCR product with MspI created by this mutation. Family studies using MspI digestion of genomic PCR products revealed that neither parent of this individual carried the mutation. These results clearly indicate that congenital adrenal hypoplasia and hypogonadotropic hypogonadism result from not only inherited but also de novo mutation in the DAX-1 gene.

Serum dehydroepiandrosterone (DHEA) and DHEA-sulfate (DHEA-S) in Alzheimer's disease and in cerebrovascular dementia

A decreased concentration of dehydroepiandrosterone sulfate (DHEA-S) in patients with Alzheimer's disease (AD) has been reported but is still controversial. In the present study, serum concentrations of DHEA and DHEA-S were determined in 19 patients with AD, 21 patients with cerebrovascular dementia (CVD) and 45 age- and gender matched elderly control individuals from the Japanese community at large. Serum concentration of DHEA among controls, patients with AD and patients with CVD did not significantly differ from one another. However, patients with AD and patients with CVD were found to have lower concentration of serum DHEA-S and a lower DHEA-S/DHEA ration compared to normal control individuals. No significant difference was observed in the concentration of serum DHEA-S or the DHEA-S/DHEA ratio between patients with AD and those with CVD. These results suggest that reduced concentrations of serum DHEA-S may not be unique to AD, but instead reflect a common phenomenon in dementing diseases. However, since serum concentration of DHEA in these patients remained unchanged, the significance of DHEA in dementia remains unclear.

Abnormalities of sex differentiation

Sex differentiation is determined by a cascade of events proceeding from chromosomal sex to the completion of sexual maturation at puberty. Many factors involved in this cascade have been identified. Here we focus on DAX-1, androgen receptor and cytochrome P450c17, and discuss their functions in sex differentiation. We analyzed the DAX-1 genes of two unrelated Japanese patients with congenital adrenal hypoplasia and hypogonadotropic hypogonadism using PCR amplification of genomic DNA and complete exonic sequencing, and established that congenital adrenal hypoplasia and hypogonadotropic hypogonadism result from not only inherited but also de novo mutation in the DAX-1 gene. Androgen insensitivity syndrome (AIS) is a good model to clarify the relationship between the structure and function of androgen receptor, the androgen receptor gene mutation and clinical phenotype. We analyzed 15 cases of AIS and demonstrate the structural and functional relationships of the androgen receptor. We have sequenced the CYP17 (P450c17) gene in DNA from several patients with 17 alpha-hydroxylase deficiency, reconstructed the mutations in a human P450c17 cDNA and expressed the mutant P450c17 in COSl cells to characterize the kinetic properties of 17 alpha-hydroxylase and 17,20-lyase activities. The molecular bases of cases clinically reported as 17 alpha-hydroxylase deficiency have turned out to be complete or partial combined deficiencies of 17 alpha-hydroxylase/17,20-lyase.

Insulin resistance associated with substitution of histidine for arginine 252 in the alpha-subunit of the human insulin receptor: trial of insulin-like growth factor I injection therapy to enhance insulin sensitivity

Mutation of the insulin receptor gene can compromise the ability of the receptor to mediate insulin action. A homozygous point mutation that results in the substitution of histidine for arginine 252 in the insulin receptor alpha-subunit has now been identified by polymerase chain reaction and single stranded conformational polymorphism analysis in a 20-yr-old Japanese woman with type A syndrome and severe insulin resistance. The proband's consanguineous parents (diabetic mother and normal father) and her sister (impaired glucose tolerance), each of whom showed an exaggerated insulin response to an oral glucose load, were heterozygous for this mutation. Her brother showed a normal insulin response and lacked the mutation, as did 50 healthy Japanese control subjects. The chronic sc administration of insulin-like growth factor I (IGF-I) improved the patient's hyperglycemia and corrected certain metabolic abnormalities over a 9-month period, even though the binding of 125I-labeled IGF-I to her cultured fibroblasts was decreased by 40% relative to that to cells from healthy controls. Studies of the binding of 125I-labeled insulin to the proband's cultured fibroblasts, to COS-I cells transfected with complementary DNA encoding the mutant insulin receptor, and to partially purified mutant receptors revealed that the Arg252-->His mutation decreased both cell surface expression and the affinity for insulin for the receptor. These observations suggest that the homozygous Arg252-->His mutation is responsible for the type A insulin resistance of the proband, whereas in the heterozygous state, the mutation results in mild insulin resistance indistinguishable from that observed in noninsulin-dependent diabetes mellitus.

The antiobesity effect of dehydroepiandrosterone in castrated or noncastrated obese Zucker male rats

Although antiobesity effect of dehydroepiandrosterone (DHEA) has been reported in rats, it remains unclear whether the effect is brought about by itself or mediated by sex steroids converted from DHEA in gonads. In the present study, to clarify this point, the effect of DHEA on growth in obese Zucker male rats was reevaluated under two conditions: with or without castration. Castration did not affect the pattern of growth curve of obese Zucker male rats. Three-months treatment of castrated Zucker rats with 0.3% DHEA in the diet resulted in dramatic decrease of body weight gain in comparison to DHEA-untreated and castrated rats. The degree of antiobesity effect of DHEA in castrated rats was almost same as that observed in non-castrated rats. These results suggest that DHEA exerted its antiobesity effect by itself rather than through conversion to testosterone in testis.