Growth factors from mesonephros implicated in gonadal and adrenal differentiation.
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Biomedical subjects
Publications and source records attributed to N Sugiyama.
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Patients with inborn errors of metabolism undergo liver transplantation, but the effect of transplanting the liver of healthy carriers of these conditions has not been fully clarified. A 6-year-old girl with classical citrullinemia, who repeatedly suffered from hyperammonemia, underwent living-related liver transplantation by using a segment of the liver of her mother, who was a heterozygote carrier for classical citrullinemia. Hyperammonemia alleviated in the patient after the transplantation, thereby dramatically improving her quality of life. Although the levels of plasma and urinary citrulline remained high postoperatively, there was no marked difference in the level of plasma citrulline up to 1 month after surgery when compared with that of previously reported orthotopic liver transplantation cases with classical citrullinemia.
Treatment of the hydrosulfido-bridged titanium-ruthenium heterobimetallic complex [Cp2Ti(mu2-SH)2RuCl(eta5-C5Me5)] (1; Cp = eta5-C5H5) with an excess of triethylamine followed by addition of [RuCl2(PPh3)3] and [[(cod)M]2(mu2-Cl)2] (M = Rh, Ir; cod = 1,5-cyclooctadiene) led to the formation of the TiRu2 and TiRuM mixed-metal sulfido clusters [(CpTi)[(eta5-C5Me5)Ru][Ru(PPh3)2](mu3-S)2(mu2-Cl)2] (3) and [(CpTi)[(eta5-C5Me5)Ru][M(cod)](mu3-S)2(mu2-Cl)] (M = Rh (4a), Ir (4b)), respectively. On the other hand, the reactions of 1 with [M(PPh3)4] (M = Pd, Pt) afforded the TiRuM trinuclear clusters [(CpTiCl)[(eta5-C5Me5)Ru][M(PPh3)2](mu3-S)(mu2-S)(mu2-H)] (M = Pd (5a), Pt (5b)) with an unprecedented M3(mu3-S)(mu2-S) core. The detailed structures of these triangular clusters 3-5 have been determined by X-ray crystallography. Crystal data: 3, triclinic, P1, a = 12.448(4) A, b = 12.773(4) A, c = 17.270(4) A, alpha = 100.16(2) degrees, beta = 99.93(2) degrees, gamma = 114.11(3) degrees, V = 2373(1) A(3), Z = 2; 4a, triclinic, P1, a = 7.714(2) A, b = 11.598(3) A, c = 14.802(4) A, alpha = 80.46(2) degrees, beta = 82.53(2) degrees, gamma = 71.47(2) degrees, V = 1234.0(6) A3, Z = 2; 4b, triclinic, P1, a = 7.729(1) A, b = 11.577(2) A, c = 14.766(3) A, alpha = 80.14(1) degrees, beta = 82.71(1) degrees, gamma = 71.55(1) degrees, V = 1231.1(4) A3, Z = 2; 5a, monoclinic, P2(1)/c, a = 11.259(4) A, b = 16.438(4) A, c = 26.092(5) A, beta = 102.23(3) degrees, V = 4719(2) A(3), Z = 4; 5b, monoclinic, P2(1)/n, a = 11.369(2) A, b = 16.207(3) A, c = 26.116(2) A, beta = 102.29(1) degrees, V = 4701(1) A3, Z = 4.
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The growth, differentiation, and death/survival of spermatogonia are precisely regulated for the proper production of spermatozoa. We have previously shown that Bcl-2 ectopically expressed in spermatogonia caused the inhibition of normal spermatogonial apoptosis and the subsequent failure of differentiation in transgenic mice. In addition, the growth of spermatogonial stem cells seemed to be temporally arrested in the transgenic mice. In the present study, we attempted to examine whether the abnormality of spermatogonia described above was caused by Bcl-2 misexpression in the spermatogonia or by an abnormal spermatogenic environment of the transgenic mice. We transplanted testicular cells of transgenic mice to seminiferous tubules of W/Wv mice in which transplanted normal testicular cells can undergo spermatogenesis. We found that the transplanted spermatogonia of the transgenic mice reproduced a series of abnormal changes including temporal growth arrest of spermatogonial stem cells and abnormal accumulation of spermatogonia in tubules, which were also observed in the testes of the transgenic mice. The results indicated that Bcl-2 inhibited apoptosis of spermatogonia and growth of spermatogonial stem cells in a cell-intrinsic manner. We also cultured testicular cells of transgenic mice and found that the spermatogonia of the transgenic mice were better able to survive than were those of wild-type mice but that their differentiation was not affected. The result suggested that failure of differentiation of the accumulated spermatogonia in the transgenic testes is not due to the abnormality of the bcl-2 misexpressing spermatogonia, but may be caused by extrinsic problems including improper interaction of spermatogonia with supporting cells.
Liver transplantation is the only clinically effective method of treating acute liver failure. However, wider application of this therapeutic modality is restricted primarily by shortage of donor organs. In the search for alternative methods of liver replacement therapy, investigators have focused on transplantation of normal allogeneic hepatocytes and on the development of liver support systems utilizing isolated hepatocytes. Since all human livers suitable for cell harvest are being used for transplantation, hepatocyte therapy using human tissue would require growing of cells in vitro. Unfortunately, although hepatocytes have tremendous capacity to proliferate in vivo, their ability to grow in culture is severely limited. Stromal cells from bone marrow and other blood-forming organs have been found to support hematopoiesis. In this paper, we show that bone marrow-derived stromal cells (BMSCs) enhance proliferation and support differentiation of rat hepatocytes in culture. Further, we demonstrate that in hepatocyte/BMSC co-cultures, clonal expansion of small hepatocytes (SH) is increased. Using semipermeable membrane cultures, we established that direct cell-cell contact is necessary for stimulation of cell proliferation. We also show that BMSCs which are in direct contact with hepatocytes and SH colonies express Jagged1. This suggests a potential role for Notch signaling in the observed effects. Finally, we present evidence that the expression and activity of liver specific transcription factors, CCAAT/enhancer binding proteins and liver specific key enzymes such as tryptophan 2,3-dioxygenase, are improved in hepatocyte/BMSC co-cultures. In conclusion, results of this study indicate that BMSCs could facilitate proliferation and differentiation of primary rat hepatocytes and their progenitors (SH) in vitro.
We report a 62-year-old Japanese man with familial frontotemporal dementia and a novel missense mutation (N296H) in exon 10 of the tau gene. The patient presented with frontal signs followed by temporal signs and parkinsonism. The brain showed localized frontotemporal lobe atrophy including the precentral gyrus and discoloration of the substantia nigra, and revealed severe neuronal loss with proliferation of tau-positive protoplasmic astroglia in the affected cerebral cortex, tau-positive coiled bodies and threads in the subcortical white matter, and tau-positive pretangle neurons in the subcortical and brain stem nuclei. There were no tau-positive neurofibrillary tangles, Pick bodies, tuft-shaped astrocytes or astrocytic plaques in the cerebral cortex. Immunoelectron microscopically, phosphorylated tau accumulated in both neurons and glial cells in different modalities, such as glial filaments in protoplasmic astroglia, straight tubules in coiled bodies, and free ribosomes in pretangle neurons. These findings suggest that tau proteins are not always assembled in abnormal filaments such as twisted ribbons, paired helical filaments and straight tubules in neurons and glial cells, which have been shown in previous cases with frontotemporal dementia and parkinsonism linked to chromosome 17. Immunoblotting of sarkosyl-insoluble tau exhibited accumulation of four-repeat tau isoforms in the brain. The N296H mutation may interfere with the ability of mutated tau to bind with microtubules and lead to tau aggregation. Further study is necessary to determine whether this mutation can account for the characteristic tau pathology of this case.
Using transgenic rice seedlings expressing a firefly luciferase (luc) gene under the control of a rice CAB (chlorophyll a/b binding protein) promoter, we demonstrated how light affects circadian clocks in the transcription of the CAB gene. Rhythmic luc expression was observed for more than 5 d under constant light and dark (DD) conditions after light/dark entrainment. After a light pulse was applied at different time points in DD various temporal patterns of CAB gene expression were individually observed. We first examined two distinct properties related to the entrainment mechanism of the circadian clock: fluence-rate dependence of free-running periods (FRPs) and phase resetting by a light pulse. Although fluence-rate dependent shortening of FRP was demonstrated, the FRP in DD was almost equal to that in constant light of a middle fluence-rate, indicating that this fluence-rate dependence may not fully describe the entrainment of the circadian clock in rice. Typical phase responses of the circadian clock by a single light pulse were also observed at the transcriptional level in rice seedlings. Thus, the phase resettings upon the light/dark transitions of daily cycles may be sufficient to explain the entrainment mechanisms of rice. We have further demonstrated that, in addition to having a gating effect to acute response, a light pulse can activate the circadian clock-controlled CAB1R gene expression at the first circadian peak in a phase-dependent manner. This suggests that light activates circadian clock activity in the diurnal CAB gene expression under daily light/dark cycles.
Dementia with Lewy bodies (DLB) is the second most frequent degenerative dementia among the elderly, following Alzheimer-type dementia (ATD). An association of DLB with CYP2D6*4, one of the cytochrome P450IID6 (debrisoquine 4-hydroxylase; CYP2D6) gene polymorphisms, was reported previously, but this is controversial. Moreover, these reports have been restricted to Caucasian populations. Therefore, we compared frequencies of CYP2D6*3, *4, and *10 mutant alleles in 17 Japanese DLB patients to those among Alzheimer-type dementia (ATD) patients and healthy controls. Polymerase chain reaction amplification and restriction fragment length polymorphism analyses were used for genotyping. No significant difference of genotype or mutant allele frequencies was detected between DLB, ATD, and healthy controls. The present results do not support the suggestion that the CYP2D6 gene is related to DLB susceptibility, at least in the Japanese population.
UNLABELLED: This study was conducted to investigate whether jugular bulb venous oxygen saturation (SjVO(2)) predicted cognitive decline after cardiac surgery with hypothermic cardiopulmonary bypass (CPB). We studied 35 patients undergoing cardiac surgery. After the induction of anesthesia, a 5.5F fiberoptic oximetry catheter was retrogradely inserted into the jugular bulb, and SjVO(2) and other cerebral oxygenation variables were analyzed before, during, and after CPB. At each point, an oxyhemoglobin dissociation curve was drawn, and the P(50) value of jugular bulb venous blood was calculated by computer analysis. Cognitive function was assessed with the revised version of Hasegawa's Dementia Scale and the Benton Revised Visual Retention Test before and early after the operation. In 15 patients (the Decline group), cognitive function was declined after surgery, whereas it remained unchanged in 20 patients (the Normal group). SjVO(2) was significantly higher and cerebral oxygen extraction was significantly lower before and during CPB in the Decline group than in the Normal group (P < 0.05). The oxygen pressure at an oxygen saturation of 50% was significantly lower before and after CPB in the Decline group than in the Normal group (P < 0.05). Logistic regression analysis showed that high SjVO(2) was a predictor of cognitive decline after cardiac surgery. We conclude that high SjVO(2) was associated with cognitive decline after cardiac surgery with hypothermic CPB. IMPLICATIONS: Jugular bulb venous oxygen desaturation has been suggested as a predictor of cognitive decline after cardiac surgery. However, the clinical value of jugular bulb venous oxygen saturation (SjVO(2)) may be limited during hypothermic cardiopulmonary bypass (CPB) when oxygen affinity to hemoglobin is increased. This study shows that high SjVO(2) before and during hypothermic CPB is a predictor of subsequent cognitive decline.
STUDY OBJECTIVES: To establish a novel method allowing detection of regional abnormalities in gas distribution at the acinar level by high-resolution CT (HRCT). PARTICIPANTS: Nonsmoking control subjects (n = 28) and patients with smoking-induced COPD (n = 47). MEASUREMENTS AND RESULTS: Changes in lung CT densities were examined by HRCT while the subjects inhaled a gas mixture consisting of 21% O(2) in SF(6) or 21% O(2) in He. HRCT images of the right upper and lower lung fields were obtained at the end of inspiration and expiration of the second and 60th breaths after the start of each gas. Introducing mean lung density (MLD) and relative area with low CT attenuation (%LAA), we analyzed the differences in acinar SF(6) and He distribution in the early phase (second breath) and in the equilibrium state (60th breath). We found that the differences in inspiratory MLD between the SF(6) and He images at the 60th breath were qualitatively consistent with the differences predicted from the physical properties of these gases. However, the differences in inspiratory MLD between the SF(6) and He images taken at the second breath were smaller than those at the 60th breath, especially in the smoking group with COPD. These differences in second-breath inspiratory MLD in the smoking group were smaller in the upper lung field than in the lower lung field. The differences in MLD between the two gases were not detected at end-expiration at the time of either the second or 60th breaths. The %LAA values did not differ between the SF(6) and He images in either the nonsmoking group or the smoking group. CONCLUSIONS: SF(6)/He-associated HRCT images obtained at end-inspiration, but not at end-expiration, in the early breathing phase are useful for predicting acinar gas distribution abnormalities in patients with COPD.
In fulminant hepatic failure, survival is not possible without recovery of sufficient hepatocyte mass. Remarkably, only a few studies exist that provide insight into the mechanisms that control proliferation of residual hepatocytes after extensive hepatocyte loss. In this regard, the role of growth-regulatory factors, including pro-inflammatory cytokines such as interleukin-6 (IL-6), is not well understood. In the present study we show that in rats with critically low (10%) hepatocyte mass, whether with or without ongoing liver cell necrosis, inhibition of liver regeneration is associated with early and sustained increase in blood IL-6 levels. Under these conditions, the signal transducer and activator of transcription (Stat3) DNA binding activity was lowered at the time of G1/S cell-cycle transition. We further demonstrate that the protein inhibitor of activated Stat3 (PIAS3) and the suppressor of cytokine signaling (SOCS-1) were up-regulated early after induction of liver failure (6-12 h). In vitro, IL-6 induced PIAS3 expression in HGF stimulated rat hepatocytes. These findings suggest that after massive hepatocyte loss, an early and rapid rise in blood IL-6 levels may weaken the hepatic regenerative response through up-regulation of Stat3 inhibitors PIAS3 and SOCS-1.
We consider the effect of three species of neutrinos with nearly degenerate mass on the cosmic structure formation in a low-matter-density universe within a hierarchical clustering scenario with a flat Gaussian initial perturbation spectrum. The matching condition for fluctuation powers at the COBE scale and at the cluster scale leads to a strong upper limit on neutrino mass. For a flat universe with matter density parameter Omega = 0.3, we obtain m(nu)<0.6 eV for the Hubble constant H0<80 km s(-1) Mpc(-1). Allowing for the more generous parameter space limited by Omega<0.4, H0<80 km s(-1) Mpc(-1) and age t(0)>11.5 Gyr, the limit is 0.9 eV.
Establishment of a bioartificial liver support system using genetically modified hepatocytes is a potential approach to improve the treatment of severe liver failure. We describe the development of an efficient ex vivo method of gene transfer into a large number of porcine hepatocytes using hemagglutinating virus of Japan (HVJ)-liposome. The transfection efficiency of HVJ-liposome into isolated porcine hepatocytes attached to microcarrier beads was evaluated by beta-galactosidase (beta-gal) staining, fluorescence activated cell sorting analysis for beta-gal and luciferase assay, respectively. To examine the function and cellular damage of transduced hepatocytes, we used enzyme-linked immunosorbent assay for porcine albumin synthesis, lidocaine clearance test (P-450 activity), aspartate aminotransferase, and lactic dehydrogenase release assays. The optimal conditions for gene transfer into the beads-attached hepatocytes using HVJ-liposome included 4 microg of deoxyribonucleic acid with 200 microg of lipid/2 x 105 cells and exposure duration of 90 min. Under these conditions, beta-gal and luciferase genes were transduced to 2.5 x 108 isolated porcine hepatocytes following attachment to the beads. Positive beta-gal staining was observed in more than 30% of the beads-attached hepatocytes. The gene transfer activity of HVJ-liposome method determined by luciferase activities was about 100-fold of that of the lipofection method. Transfected porcine hepatocytes remained functional without any significant cell damage. Our results demonstrated that HVJ-liposome mediated gene transfer into microcarrier-attached porcine hepatocytes is an efficient and nontoxic method suitable for a bioartificial liver support sytem.
Decreased activity of debrisoquine 4-hydroxylase (CYP2D6), which participates in hepatic metabolism of several frequently used neuroleptics and antidepressants, is inherited as an autosomal recessive trait through polymorphic CYP2D6 gene alleles. In eastern Orientals, a C --> T substitution at nucleotide 188 (Pro34Ser) is primarily responsible for decreased ability to metabolize CYP2D6 substrates. We therefore studied a possible association between neuroleptic malignant syndrome (NMS) and the C188T mutation. We examined the frequency of the C188T mutation by polymerase chain reaction and restriction fragment length polymorphism analysis in 36 Japanese patients previously diagnosed with NMS and 107 neuroleptic-treated schizophrenic patients with no NMS history. The C188T allele frequency was 0.417 in NMS patients and 0.463 in patients without NMS. No significant allele or genotype associations were observed. We cannot conclude that low CYP2D6 activity genotype causes susceptibility to NMS in Japanese patients.
We produced an immortalized colonic epithelial cell line, MCE301, using fetal mice transgenic for the temperature-sensitive simian virus 40 large T-antigen gene. MCE301 cells showed epithelial-like morphology and maintained tight connections with neighboring cells. The cells grew at a permissive temperature (33 degrees C), but the growth of the cells was significantly prevented at the nonpermissive temperature (39 degrees C). The cells expressed large T-antigen at 33 degrees C but not at 39 degrees C. MCE301 cells were not transformed, as judged by the absence of anchorage-independent growth in soft agar gel and lack of tumor formation in nude mice. Electron microscopic studies showed that the cells formed microvilli-like structures on the cell surface and junctional complexes such as tight junctions and desmosomes between the cells. The cells expressed cytosketal (acidic cytokeratins and actin), basement membrane (laminin and collagen type IV) and junctional complex proteins (ZO-1 and desmoplakin I + II), as judged by specific antibodies. Fetal bovine serum, epidermal growth factor, insulin-like growth factor and insulin significantly increased the cell growth at 33 degrees C. Moreover, MCE301 cells expressed colonic mucin Muc2 mRNA as demonstrated by reverse transcriptase-polymerase chain reaction, indicating that the cells originate from mucus-secreting cells. Alkaline phosphatase, a brush border-associated enzyme, was detected in the cells. Sodium butyrate (2 mM), an inducer of cellular differentiation, markedly elevated alkaline phosphatase activity. Thus, the present mouse colonic epithelial cell line MCE301 possessing these unique characteristics should provide a useful in vitro model of colonic epithelium.
We encountered a case with long-term remission of Cushing's disease due to pituitary apoplexy. The apoplexy of pituitary adenoma secreting adrenocorticotropin hormone was diagnosed by successive and timely magnetic resonance imaging when the symptoms of the patient were not yet severe and anterior pituitary dysfunction was only a transient reduction of growth hormone secretion. Seven years after the first episode of pituitary apoplexy, hypercorticism recurred, and pituitary magnetic resonance imaging showed a regrowth of the pituitary adenoma. A spontaneous remission of Cushing's disease without significant visual, neurologic or hormonal defects seems to be a much more common phenomenon than has been previously suggested. Cases with relapse after spontaneous remission of Cushing's disease are rare and the duration of remission in previous reports was within 5 years. We observed such a patient with a 7 year-remission caused by pituitary apoplexy. We consider that a careful long-term follow-up is required for patients with Cushing's disease whose remission was due to pituitary apoplexy.