High levels of DNA polymerase ß mRNA corresponding with the high activity in Graves' thyroid tissue.

INTRODUCTION: High DNA polymerase ß activity has been observed in the thyroid tissue of patients with Graves' disease (Nagasaka et al. in Metabolism 37:1051-1054, 1988). This fact aroused our interest in whether the alteration of DNA polymerase ß activity depends on DNA polymerase ß (DNA poly ß) mRNA levels, which may be modulated by thyroid-stimulating hormone (TSH) or thyroid-stimulating substances, i.e. TSH receptor antibody (TRAb). RESULT: Addition of TSH or TRAb to primary cultures of Graves' disease thyroid cells for 4 h led to no increase in DNA poly ß mRNA levels. In contrast, thyroid hormone synthesizing enzyme, peroxidase, mRNA levels increased fivefold after coculture with TSH and TRAb, even though DNA poly ß activity and mRNA levels are already significantly higher in Graves' disease thyroid tissues, compared with normal thyroid tissue. DISCUSSION: These results indicate that DNA poly ß expression in Graves' disease thyroid cells may be maximally activated or plateau in response to thyroid-stimulating immunoglobulins, or that the activation of to poly ß expression may occur via pathways other than the G protein and cyclic AMP system.

Unconventional magnetic and thermodynamic properties of S=1/2 spin ladder with ferromagnetic legs.

We have succeeded in synthesizing single crystals of a new organic radical 3-Cl-4-F-V [3-(3-chloro-4-fluorophenyl)-1,5-diphenylverdazyl]. Through the ab initio molecular orbital calculation and the analysis of the magnetic properties, this compound was confirmed to be the first experimental realization of an S=1/2 spin-ladder system with ferromagnetic leg interactions. The field-temperature phase diagram indicated that the ground state is situated very close to the quantum critical point. Furthermore, we found an unexpected field-induced successive phase transition, which possibly originates from the interplay of low dimensionality and frustration.

Diversity and systematics of the sequestrate genus Octaviania in Japan: two new subgenera and eleven new species.

The sequestrate fungi of Japan, including truffle and truffle-like fungi, have not been well characterized but are potentially diverse. We investigated the diversity and phylogeny of Japanese Octaviania specimens using a multifaceted approach including scanning and transmission electron microscopy as well as analysis of nuclear ribosomal DNA (ITS and LSU) and EF-1α (tef1) sequences. Phylogenetic analyses indicate that the genus Octaviania is divided into three major clades, and that there are at least 12 species-level lineages in Japan. Accordingly, we describe two new subgenera, Parcaea and Fulvoglobus, and eleven new species. Subgenus Parcaea accommodates four highly divergent, but macromorphologically almost indiscernible cryptic species. We discuss not only the diversity and species delimitation within the genus Octaviania but also the phylogeography of the Japanese taxa and their relatives.

Insulinoma may mask the existence of Type 1 diabetes.

BACKGROUND: Insulinoma is a tumour of insulin-producing cells of the pancreas and is known to be one of the causes of hypoglycaemia. Usually, appropriate removal of the insulinoma results in normalization of blood glucose levels. However, we found novel cases of insulinoma, in which hyperglycaemia developed soon after resection of the insulinoma. CASE REPORT: We encountered two patients with repeated hypoglycaemia caused by insulinoma. Following removal of the insulinoma, unanticipated hyperglycaemia was observed in both patients. Thereafter, their blood tests revealed low levels of serum C-peptide and high titres of anti-glutamic acid decarboxylase antibody, indicating concomitant Type 1 diabetes. Indeed, histological examination of the resected specimen revealed that one patient showed insulitis in non-tumorous pancreatic tissue in which ß-cells had already disappeared. Moreover, inflammatory cells infiltrated the insulinoma, as if it were insulitis of Type 1 diabetes, suggesting the existence of anti-islet autoimmunity. CONCLUSION: These are first cases of insulinoma associated with underlying Type 1 diabetes. Physicians should be aware of the possibility that insulinoma may mask Type 1 diabetes, and measurement of anti-islet autoantibodies may be helpful to find underlying Type 1 diabetes, such as in these cases. It is pathologically interesting that the immune cell infiltration into insulinoma may be suggestive of anti-islet autoimmunity.

Comparison of time-action profiles of insulin glargine and NPH insulin in normal and diabetic dogs.

Intermediate insulin injections are commonly used for glycemic control in insulin dependent diabetic dogs acting as a replacement for natural insulin. Neutral Protamin Hagedorn (NPH) insulin and insulin glargine are two types of injectable insulin preparations commonly used in humans. In our study, we investigated the time-action profiles of both aforementioned insulin preparations in normal dogs in order to determine whether co-administration of NPH and glargine would be of benefit to insulin dependent diabetic dogs as it is for humans suffering from insulin dependent diabetes. Time-action profiles of NPH insulin and insulin glargine in normal dogs demonstrated a clear difference between both insulin preparations confirming that NPH insulin is an intermediate-acting preparation whereas insulin glargine is a long-lasting preparation. In addition, co-administration of NPH insulin and insulin glargine resulted in tight glycemic control as compared to NPH insulin alone in insulin dependent diabetic dogs. However, co-administration result in hypoglycemia at the dosages tested.

Association of symptomless TMJ sounds with occlusal force and masticatory performance in older adults.

This study investigated associations between temporomandibular joint (TMJ) sounds and occlusal force or masticatory performance stratified by posterior occlusal supports in older Japanese adults. The subjects consisted of 1646 independently living people over 60 years. Masticatory performance, occlusal force, TMJ sounds and maximal mouth opening were examined. Posterior occlusal supports were classified by the Eichner Index. The prevalence of TMJ sounds was 27.7%, limitation of mouth opening (< 40 mm) was 7.9% and TMJ pain was only 1.5%. In the Eichner C group, TMJ sounds were significantly associated with lower occlusal force (OR = 3.20, P = 0.046) and lower masticatory performance (OR = 3.18, P = 0.041) after controlling for gender and age. These associations were not found in the Eichner A and B groups. Within the limitations of this study, the presence of TMJ sounds, even if they were symptomless, was associated with impairment of masticatory function in older adults with reduced occlusal support.

[Extrapleural pneumonectomy of malignant pleural mesothelioma].

We analyzed 7 patients with malignant pleural mesothelioma who underwent extrapleural pneumonectomy. Six men and a woman had a mean age of 65 years old. The postoperative mortality rate was 14% (1 death) and morbidity, 43% (3 cases). According to staging of International Mesothelioma Interest Group, 2 patients had stage I disease, 1 did stage II, 3 did stage III and 1 did stage IV. Local recurrences were found in 3 patients and metastasis in 2. In patients with local recurrences, 2 had irradiation with chemotherapy and 1, irradiation. In patients with recurrences of metastasis, 1 had chemotherapy and 1, supportive care. Seven patients with extrapleural pneumonectomy and 10 without surgery had median survivals of 16 months and 10 months, 1-year survival rates of 71% and 40% and 2-year survival rates of 57% and 0% respectively (p=0.071). Extrapleural pneumonectomy with adjuvant therapy could be effective treatment for malignant pleural mesothelioma.

Property of thimerosal-induced decrease in cellular content of glutathione in rat thymocytes: a flow cytometric study with 5-chloromethylfluorescein diacetate.

There is a concern on the part of public health community that adverse health consequences by thimerosal, a preservative in vaccines for infants, may occur among infants during immunization schedule. Therefore, the effect of thimerosal on cellular content of glutathione was examined on thymocytes obtained from 4-week-old rats using a flow cytometer and 5-chloromethylfluorescein diacetate. Thimerosal at concentrations ranging from 1 to 10 microM reduced the cellular content of glutathione in a concentration-dependent manner, and the complete depletion of cellular glutathione was observed when the cells were treated with 30 microM thimerosal. L-Cysteine significantly attenuated the actions of thimerosal to reduce the glutathione content and to increase the intracellular Ca2+ concentration. Prolonged incubation (24 h) with 1-3 microM thimerosal induced the apoptosis. The cytotoxic action of thimerosal was greatly augmented when the cells suffered oxidative stress induced by H2O2. It may be unlikely that thimerosal exerts potent cytotoxic action under the in vivo condition because the blood concentration of thimerosal after receiving vaccines does not seem to reach micromolar range and nonprotein thiols at micromolar concentrations are present in the blood.

Expression and localization of nm23-H1 in the human placenta.

The involvement of the nm23 gene, initially documented as a putative metastasis-suppressor gene, in normal development and differentiation has been supported by several investigations. To date, however, localization and expression pattern of nm23 in the human placenta has not been determined. In the present study, the expression of nm23-H1 was examined by Northern blot and immunohistochemical analyses in human placentas from various stages of gestation. In first trimester placenta, the villous cytotrophoblast and the extravillous trophoblast exhibited strong cytoplasmic staining for nm23-H1. In second trimester and term placentas, the few cytotrophoblasts present showed less intense staining than those in first trimester placenta. Northern blot analysis demonstrated a progressive decrease in nm23-H1 gene expression with advancing gestational age, which is consistent with the results obtained by immunohistochemistry. These findings suggest that nm23-H1 is involved in the differentiation process of the trophoblast, and high levels of nm23-H1 expression seem to reflect the proliferating, less differentiated state of that reserve.

Effect of eicosapentaenoic acid ethyl ester on hypothyroid function.

Thyroid hormones affect reactions in almost all pathways of lipid metabolism. It has been reported that plasma free fatty acid (FFA) concentration in hypothyroidism is generally within the normal range. In this study, however, we show that plasma FFA concentration in some hypothyroid patients is higher than the normal range. Symptoms of thyroid dysfunction in these individuals were less severe than those of patients with lower plasma FFA concentrations. From these findings we hypothesized that the change in FFA concentration must correlate with thyroid function. Using an animal model, we then examined the effect of highly purified eicosapentaenoic acid ethyl ester (EPA-E), a n-3 polyunsaturated fatty acid derived from fish oil, on thyroid function in 1-methyl-2-imidazolethiol (MMI)-induced hypothyroid rats. Oral administration of EPA-E inhibited reduction of thyroid hormone levels and the change of thyroid follicles in MMI-induced hypothyroid rats. These findings suggest that FFA may affect thyroid functions and EPA-E may prevent MMI-induced hypothyroidism.

Left-hand-assisted laparoscopic resection of hepatocellular carcinoma in an accessory liver.

We report a left-hand-assisted laparoscopic resection of hepatocellular carcinoma that developed in an accessory liver in a 47-year-old man. Preoperative assessment of the location of the tumor and the feeder vessels by combined selective angiography and computed tomography studies predicted the feasibility of laparoscopic procedures for complete removal of the tumor. In an attempt to avoid direct contact of the tumor capsule with rigid instruments during the operation, left-hand-assisted procedures were attempted. The encapsulated mass, 6 x 5 x 3 cm in size, was located on the posterior side of the left diaphragm, and a thin stalk between the tumor and the margin of the left lateral segment of the liver proper was recognized. Hand-assisted procedures ensured the complete mobilization of the lesion with an adequate margin, without any unexpected capsular tear. Left-hand-assisted laparoscopic procedures would be feasible for the easy and safe resection of localized hepatocellular carcinoma developing in an accessory liver.

Expression of nm23-H1 in hydatidiform mole and its relationship with the development of postmolar disease.

The aim of the present study was to investigate the expression of nm23-H1 in human placenta, hydatidiform mole and choriocarcinoma cells. Nm23-H1 protein was localized in the cytotrophoblast, but not in the syncytiotrophoblast. In the hydatidiform mole cases with subsequent spontaneous remission, nm23-H1 mRNA levels were significantly lower than those in first-trimester placentas. However, its levels were elevated in the hydatidiform mole cases that progressed to persistent gestational trophoblastic disease and were comparable to those of first-trimester placentas, and they were further elevated in choriocarcinoma cells. The present data suggest an association of nm23-H1 for the proliferation activity of trophoblast, and its increased expression may influence the development of persistent trophoblastic disease.

CCAAT/enhancer-binding protein beta is required for activation of genes for ornithine cycle enzymes by glucocorticoids and glucagon in primary-cultured hepatocytes.

Transcription of genes for enzymes of the ornithine cycle is activated by hormones such as glucocorticoids and glucagon. Promoters and enhancers of several genes for the enzymes interact with the CCAAT/enhancer-binding protein (C/EBP) family of transcription factors, and C/EBPbeta has been suggested to mediate glucocorticoid response of the gene for arginase, the last enzyme of the cycle. To determine the contribution of C/EBPbeta to hormonal regulation of genes for ornithine cycle enzymes, we examined mice with targeted disruption of the C/EBPbeta gene. Induction of genes for the enzymes by intraperitoneal injection of dexamethasone and glucagon was almost intact in the liver of C/EBPbeta-deficient mice. On the other hand, in primary-cultured hepatocytes derived from C/EBPbeta-deficient mice, induction of genes for the first enzyme carbamylphosphate synthetase, as well as for arginase, in response to dexamethasone and/or glucagon was severely impaired. Therefore, C/EBPbeta is required for hormonal induction of the genes for ornithine cycle enzymes in primary-cultured hepatocytes, while the deficiency of C/EBPbeta is compensated for in vivo.

Hand-assisted laparoscopic splenectomy for idiopathic thrombocytopenic purpura during pregnancy.

A successful case of a hand-assisted laparoscopic splenectomy with low-pressure pneumoperitoneum for autoimmune thrombocytopenic purpura in a patient at 23 weeks' gestation is reported. Preoperative splenic arterial embolization was performed on the same day as the operation using painless contour embolic material and super-absorbent polymer microspheres. The abdominal wall retraction method first was applied to avoid the effects of pneumoperitoneum on systemic hemodynamic alterations. However, a sufficient surgical view could not be obtained, as the intra-abdominal organs were elevated because of the enlarged uterus. A surgical view with 4 to 6-mm Hg pneumoperitoneum was available for the hand-assisted splenectomy. The postoperative course was uneventful, and the patient vaginally delivered a healthy infant. A hand-assisted laparoscopic splenectomy with low-pressure pneumoperitoneum after splenic arterial embolization would be feasible for patients with autoimmune thrombocytopenic purpura during a relatively advanced pregnancy.

The gene for hepatocyte nuclear factor (HNF)-4alpha is activated by glucocorticoids and glucagon, and repressed by insulin in rat liver.

The gene for a transcription factor hepatocyte nuclear factor-4alpha (HNF-4alpha) is responsible for maturity-onset diabetes of the young, type 1. We examined hormonal regulation of the HNF-4alpha gene in the liver. Stimulation of primary-cultured rat hepatocytes with dexamethasone or glucagon led to induction of HNF-4alpha mRNA, being antagonized by insulin. In the liver of streptozotocin-induced diabetic rat, mRNA and protein levels for HNF-4alpha were elevated, and were normalized by insulin treatment. Therefore, HNF-4alpha in the liver is likely to be involved in the regulation of glucose metabolism in response to these hormones.

Reverse transcriptase is elevated in the thyroid tissue from Graves' disease patients.

OBJECTIVE: Hypertrophy of the thyroid gland in Graves' disease is related to an autoimmune response directed against TSH receptors found in thyroid cells. Recently, investigators have suggested that autoimmune diseases, including thyroid diseases may, at least in part, correlate with the expression of proteins encoded by the retroviral genome. In the present study, to confirm the correlation between thyroid autoimmune disorders and retroviral infections, we examined reverse transcriptase (RT) activity in thyroid tissues as a marker of retroviral infection. PATIENTS AND MEASUREMENTS: Thyroid tissues obtained at surgery from patients with various thyroid disorders (normal thyroid adjacent to adenoma, six cases; Graves' disease thyroid tissue, 25 cases; adenoma, eight cases; papillary carcinoma, 12 cases; Graves' disease peripheral blood lymphocytes, 11 cases) were used for RT assay, using a specific, improved assay system. RESULTS: Thyroid tissue extracts from patients with Graves' disease contained high RT activity which resembled that demonstrated in retroviruses. The RT existed in the thyroid tissue as a complex, with endogenous template RNA, and the activity was confirmed not to be due to other DNA polymerases. CONCLUSION: Retroviral RT distinguished from known cellular DNA polymerases is expressed in the thyroids of patients with Graves' disease. In a permissive genetice and immunological environment, retroviral DNA integrated into genomic DNA could precipitate the onset of Graves' disease.

Novel nikkomycin analogues: inhibitors of the fungal cell wall biosynthesis enzyme chitin synthase.

A series of novel nikkomycin analogue inhibitors of the chitin synthase of fungal cell wall was synthesized and evaluated for their inhibitory activities. Among them, the compound having a phenanthrene group at the terminal amino acid was found to possess strong anti-chitin synthase activity.

Neonatal periventricular leukomalacia preceded by fetal periventricular echodensity.

OBJECTIVE: The purpose of this prospective study is to verify whether fetal periventricular echodensity (PVE) precedes neonatal periventricular leukomalacia (PVL). METHODS: Fetal brains were studied with transvaginal scan in 63 high-risk fetuses from 17 to 32 weeks of pregnancy, PVE echogenicity was quantified with ultrasonic histogram, and neonatal brains and clinical courses were studied after birth. RESULTS: No fetal cystic PVL was found, instead, fetal PVE was detected in 42 fetuses. The quantified echogenicity value was higher in PVE than in normal brain. Four cases developed neonatal PVL among 28 preterm and 1 among 14 term births. Neonatal PVL developed in the 23 cases of persistent fetal PVE, whereas no neonatal PVL was found when fetal PVE was negative or disappeared. Cord compression signs were common in PVL cases. CONCLUSION: Neonatal PVL was preceded by antepartum persistent fetal PVE in the present study.

Induction of endothelial nitric-oxide synthase in rat brain astrocytes by systemic lipopolysaccharide treatment.

In the brain, three isoforms of nitric oxide (NO) synthase (NOS), namely neuronal NOS (nNOS, NOS1), inducible NOS (iNOS, NOS2), and endothelial NOS (eNOS, NOS3), have been implicated in biological roles such as neurotransmission, neurotoxicity, immune function, and blood vessel regulation, each isoform exhibiting in part overlapping roles. Previous studies showed that iNOS is induced in the brain by systemic treatment with lipopolysaccharide (LPS), a Gram-negative bacteria-derived stimulant of the innate immune system. Here we found that eNOS mRNA is induced in the rat brain by intraperitoneal injection of LPS of a smaller amount than that required for induction of iNOS mRNA. The induction of eNOS mRNA was followed by an increase in eNOS protein. Immunohistochemical analysis revealed that eNOS is located in astrocytes of both gray and white matters as well as in blood vessels. Induction of eNOS in response to a low dose of LPS, together with its localization in major components of the blood-brain barrier, suggests that brain eNOS is involved in early pathophysiologic response against systemic infection before iNOS is induced with progression of the infection.