Possible involvement of proteolytic degradation of tyrosinase in the regulatory effect of fatty acids on melanogenesis

The purpose of this study was to investigate the mechanism of fatty acid-induced regulation of melanogenesis. An apparent regulatory effect on melanogenesis was observed when cultured B16F10 melanoma cells were incubated with fatty acids, i.e., linoleic acid (unsaturated, C18:2) decreased melanin synthesis while palmitic acid (saturated, C16:0) increased it. However, mRNA levels of the melanogenic enzymes, tyrosinase, tyrosinase-related protein 1 (TRP1), and tyrosinase-related protein 2 (TRP2), were not altered. Regarding protein levels of these enzymes, the amount of tyrosinase was decreased by linoleic acid and increased by palmitic acid, whereas the amounts of TRP1 and TRP2 did not change after incubation with fatty acids. Pulse-chase assay by [35S]methionine metabolic labeling revealed that neither linoleic acid nor palmitic acid altered the synthesis of tyrosinase. Further, it was shown that linoleic acid accelerated, while palmitic acid decelerated, the proteolytic degradation of tyrosinase. These results suggest that modification of proteolytic degradation of tyrosinase is involved in regulatory effects of fatty acids on melanogenesis in cultured melanoma cells.

Comparisons between hemodynamics, during and after bathing, and prognosis in patients with myocardial infarction

The purpose of this study was to establish the safest way to bathe patients with myocardial infarction (MI) through measuring the hemodynamics during and after bathing. Seventy patients with MI were bathed supine in a Hubbard tank filled with 42 degrees C tap water for 5 min. The subjects were divided into 2 groups depending on their hemodynamic values 10 min after bathing: pulmonary capillary wedge pressure unchanged even after bathing (group A), and decreased pressure after bathing (group B). The left ventricular ejection fraction of group B was significantly higher than that of group A: 53.6% vs. 39.7%, respectively (p<0.01). The physical work capacity of group B was significantly higher at 5.6 METs, than that of group A with 4.5 METs (p<0.05). During the average of their 37-month follow-up period, there were 3 cardiac events in group B and 6 in group A. There were 2 cardiac events during bathing, both of which occurred in group A. When patients with MI take a bath, it is essential to closely monitor them, especially to those patients with lower cardiac function, because they have a higher possibility of a cardiac event.

An accessory lobe of the liver disturbing closure of the umbilical ring

The authors report a small omphalocele involving an accessory lobe of the liver (ALL) embedded in a cranial portion of the amniotic sac. The pedicle of liver tissue was markedly elongated. In this case, it was reasonable to assume that the ALL was formed during development of the embryonic body-wall folds and disturbed complete closure of the umbilical ring. Surgical resection of the ALL was performed to avoid its postoperative torsion. The pertinent literature is also reviewed.

MIC-A polymorphism in Japanese and a MIC-A-MIC-B null haplotype

A polymorphic gene, MIC-A, is one of the MIC family of genes which is composed of a group of homologous genes interspersed in the class III and class I regions of the major histocompatibility complex. MIC-A is located 46 kilobases (kb) centromeric of HLA-B, and is preferentially expressed in the epithelial cells and intestinal mucosa. Recently, MIC-A and the closely related MIC-B were reported as the molecules that conferred specificity in the recognition by the Vdelta1gammadeltaT cells. In the present study, polymorphic exons 2, 3, and 4 of the MIC-A gene were analyzed using the polymerase chain reaction-single-strand conformation polymorphism method. The number of patterns found in exons 2, 3, and 4 were 5, 6, and 4, respectively, in 114 healthy Japanese subjects. Eight MIC-A alleles were observed in Japanese individuals, among which one, tentatively named MIC-AMW, has not previously been reported. There was a strong linkage disequilibrium between MIC-A and HLA-B loci: each MIC-A allele showed strong association with a particular HLA-B group. In contrast, B*3901 showed association with multiple MIC-A alleles. Furthermore, the existence of a MIC-A-MIC-B null haplotype, which is associated with HLA-B*4801, was identified. In this haplotype, a large-scale deletion (of approximately 100 kb) including the entire MIC-A gene was indicated and the MIC-B gene possessed a stop codon.

Microvascular endothelial cells remodel cultured adult cardiomyocytes and increase their survival

We investigated the paracrine effect of cardiac microvascular endothelial cells (MVEC) on cultured adult rat cardiomyocytes (ARC). ARC were exposed for 8 days to serum-free medium (CM) conditioned by MVEC. Controls were grown in FCS or FCS-free medium. Protein synthesis of CM-stimulated ARC increased twofold versus 5% FCS-stimulated cells until day 8. Seventy-nine percent of CM-treated myocytes survived, whereas only twenty-four percent of FCS-free ARC retained viability. The phenotype of myocytes exposed to CM was different from control. Analysis by confocal laser microscopy of CM-stimulated myocytes showed actin staining throughout the whole cell body up to the peripheral extensions, with concomitant appearance of myomesin in a cross-striated pattern. The reexpression of fetal alpha-smooth muscle actin determined immunohistochemically and by Western blot increased from day 6 in CM-treated cells, whereas ARC grown in up to 20% serum were negative. These effects could not be mimicked by any of the other cardioactive substances tested here, indicating a novel trophic factor in CM.

Cardiac microvascular endothelial cells express alpha-smooth muscle actin and show low NOS III activity

We established a culture system of porcine coronary microvascular endothelial cells (MVEC) with high cellular yield and purity >98%. Endothelial origin was confirmed by immunostaining, immunoblotting and fluorescence-activated cell sorter (FACS) analysis using low-density lipoprotein uptake, CD31, von Willebrand factor, and the lectin Dolichos biflorus agglutinin. MVEC were positive for alpha-smooth muscle actin in culture and in myocardium, as confirmed by FACS. Of the primary MVEC, approximately 30% expressed nitric oxide synthase (NOS) III in numbers decreasing from the first passage (6 +/- 1%) to the second passage (4 +/- 1%; P < 0.001 vs. primary isolates), whereas approximately 100% of aortic endothelial cells (AEC) expressed NOS III. In AEC, NOS III activity (pmol citrulline. mg protein-1. min-1) was 80 +/- 10 and was nearly abolished in the absence of calcium (5 +/- 1, P < 0.001). In primary MVEC, however, NOS III activity in the presence and absence of calcium was 20 +/- 4 and 25 +/- 5, respectively. We conclude that cardiac MVEC, in contrast to AEC, contain alpha-smooth muscle actin, show low-grade NOS III activity, and provide a suitable in vitro system for the study of endothelial pathophysiology.

Pioglitazone prevents mice from multiple low-dose streptozotocin-induced insulitis and diabetes

Macrophage infiltration into pancreatic islets is thought to be an initial event inducing insulitis in the development of type 1 diabetes. Thiazolidinedione is a direct ligand for peroxisome proliferator-activated receptor-gamma, recently reported to inhibit macrophage activation, including cytokine production and type 2 nitric oxide synthase expression. We investigated the effect of pioglitazone, a thiazolidinedione compound, on the development of multiple low-dose streptozotocin (MLDS)-induced autoimmune diabetes in mice. CD-1 mice intraperitoneally injected with five daily sub-diabetogenic doses (30 or 40 mg/kg body weight) of streptozotocin developed mononuclear cell infiltration in and around islets, followed by hyperglycemia. Oral administration of pioglitazone (0.01% food admixture) from 7 days before the first streptozotocin injection prevented or delayed the development of diabetes induced by MLDS. Histologically, pioglitazone blocked the infiltration of mononuclear cells into islets in MLDS mice. Peritoneal macrophages from MLDS mice at day-7 produced significantly large amount of nitric oxide compared with those from control mice. Such activation of peritoneal macrophages was not observed in pioglitazone-treated MLDS mice. These findings suggest that pioglitazone blocks the autoimmune process in the development of MLDS diabetes, partly by inhibiting the macrophage activation.

The critical region for Behçet disease in the human major histocompatibility complex is reduced to a 46-kb segment centromeric of HLA-B, by association analysis using refined microsatellite mapping

The HLA-B51 allele is known to be associated with Behçet disease. Recently, we found a higher risk for Behçet disease in the MICA gene, 46 kb centromeric of HLA-B, by investigation of GCT repetitive polymorphism within exon 5 of MICA. The pathogenic gene causing Behçet disease, however, has remained uncertain. Here, eight polymorphic microsatellite markers, distributed over a 900-kb region surrounding the HLA-B locus, were subjected to association analysis for Behçet disease. Statistical studies of associated alleles detected on each microsatellite locus showed that the pathogenic gene for Behçet disease is most likely found within a 46-kb segment between the MICA and HLA-B genes. The results of this mapping study, and the results of an earlier study of ours, suggest that MICA is a strong candidate gene for the development of Behçet disease.

Morphological investigation of the enteric nervous system in Hirschsprung's disease and hypoganglionosis using whole-mount colon preparation

BACKGROUND/PURPOSE

A suction rectal mucosal biopsy with positive staining for acetylcholinesterase is a useful test for diagnosis of Hirschsprung's disease (HD). However, hypoganglionosis has not been diagnosed by a rectal mucosal biopsy. The authors morphologically examined the enteric nervous systems in HD and hypoganglionosis patients using whole-mount preparations.

METHODS

Six HD patients, two hypoganglionosis patients, and 10 with normally innervated colons were examined. Colonic specimens were incubated with the primary antibodies against protein gene product 9.5 (PGP 9.5) mixed with S-100b protein, tyrosine hydroxylase (TH), calcitonin gene-related peptide (CGRP), substance P (SP), and neurofilament protein 200 kDa (NFH). They were observed by histochemical technique using light-microscopy in whole-mount preparations.

RESULTS

The aganglionic distal colon had thick nerve strands stained with PGP 9.5 mixed with S100 or NFH located in the layer between the longitudinal muscle and the circular one, and the submucosal layer. The nerve strands in the myenteric layer contained few CGRP- and SP-positive fibers and ran along the long axis of the intestine. Ganglion cells appeared along with those thick nerve strands in the transitional zone of HD. In hypoganglionosis, we found small myenteric ganglia with no thick nerve strands.

CONCLUSIONS

The enteric nervous system in oligoganglionic segments of HD morphologically differed from the one in hypoganglionosis. A suction rectal mucosal biopsy would be of no use in the diagnosis of hypoganglionosis.

Expression of salmon corticotropin-releasing hormone precursor gene in the preoptic nucleus in stressed rainbow trout

The behavior of genes encoding the corticotropin-releasing hormone (CRH) precursor in response to stress has not been extensively studied in teleosts. To clarify this problem, CRH cDNAs were isolated from a hypothalamic cDNA library of sockeye salmon, Oncorhynchus nerka, by screening with PCR products amplified from the hypothalamic mRNA with primers deduced from the sequence of the sucker CRH precursor. Two types of PCR products with a high degree of sequence homology were identified (CRH-I and CRH-II). A cDNA encompassing the entire coding sequence of the salmon CRH-I precursor was isolated. The salmon CRH-I cDNA encodes a 167-amino-acid precursor, which consists of a signal sequence, a cryptic peptide, and the carboxyl terminal 41-amino-acid sequence of CRH. The deduced amino acid sequence of salmon CRH peptide exhibits 66 to 80% homology with mammalian, Xenopus, and sucker CRHs, whereas it shows about 50% homology with sucker, carp, or sole urotensin I, a CRH-related neuropeptide in teleost fish. In situ hybridization histochemistry demonstrated CRH mRNA-positive perikarya in the preoptic nucleus in rainbow trout, Oncorhynchus mykiss, when the fish were stressed by confinement. Adjacent sections hybridized with probes for salmon vasotocin (VT) precursor showed many VT mRNA-positive neurons also in the preoptic nucleus, suggesting a colocalization of CRH and VT mRNAs in the same magnocellular neurons in the rainbow trout brain. The present results suggest that CRH may have important roles in the control of stress responses in salmonid fish.

Contribution of the renal medulla to enhanced ketogenesis with Ringer's acetate administration during hepatic inflow occlusion

We have reported that the administration of Ringer's acetate solution (AR) maintains plasma ketone body concentrations even during hepatic ischemia due to enhanced ketogenesis in the kidney. In this study we tried to clarify which part of the kidney, cortex or medulla, contributes to the enhanced ketogenesis. During 20 minutes of hepatic inflow occlusion, AR or Ringer's lactate solution (LR) was administered. Ketone body concentrations in arterial and renal venous blood and renal cortical and medullary tissue were measured enzymatically. Results are expressed as means +/- SEM. At 20 minutes of hepatic inflow occlusion, arterial ketone body concentrations decreased to 38% of preischemic values with the LR infusion but increased under AR administration and were four times higher than that with LR. The renal arteriovenous difference in ketone body concentration was 16 +/- 14 micromol/ml before hepatic inflow occlusion and -52 +/- 14 with AR administration, indicating that renal ketogenesis occurred during hepatic ischemia. Total ketone body concentrations in the renal cortex and medulla were 56 +/- 6 and 61 +/- 5 micromol/g, respectively with LR, but increased to 186 +/- 29 and 248 +/- 25 micromol/g, respectively during AR administration. The concentration in the medulla was higher (p = 0. 12) than that in the cortex but did not reach statistical difference. Renal ketogenesis increases during hepatic inflow occlusion with AR administration. It is likely that the enhancement of ketogenesis takes place predominantly in the medulla of the kidney.

In vivo gene transfer to mouse spermatogenic cells by deoxyribonucleic acid injection into seminiferous tubules and subsequent electroporation

An in vivo gene transfer technique for living mouse testes was used to develop a novel transient expression assay system for transcriptional regulatory elements of spermatogenic specific genes. The combination of DNA injection into seminiferous tubules and subsequent in vivo electroporation resulted in an efficient and convenient assay system for gene expression during spermatogenesis. The transfer of the firefly luciferase reporting gene driven by the Protamine-1 (Prm-1) enhancer region revealed a significant increase in the activity of the reporter enzyme. Histochemical studies of the transfer of the lacZ gene driven by the Prm-1 enhancer showed specific lacZ expression only in haploid spermatid cells in adult testes, corresponding with the expression pattern of endogenous Prm-1. We were able to detect long-lasting transgene expression in the transfected spermatogenic cells. A group of spermatogenic differentiating cells maintained the transfected lacZ expression after more than 2 mo of transfection, suggesting that spermatogenic stem cells and/or spermatogonia could also incorporate foreign DNA and that the transgene could be transmitted to the progenitor cells derived from a transfected proliferating germ cell.

The activities of the Tokyo Center

The main World Health Organization (WHO) activities of the Tokyo Center are as follows: (1) It performed the research project entitled 'A Bio-Psycho-Social Study on Children with Emotional and Behavioral Problems' in cooperation with the Beijing and Seoul Centers from 1985 to 1987. These results suggested that the deviant behavior of children in the general population had no biological background, but presumably stemmed from psychosocial disadvantages. (2) It has participated in a field trial for the proposed draft for chapter V of the ICD-10 as the Field Trial Coordinating Center in Japan since 1986 and the first Japanese edition of the ICD-10 Classification of Mental and Behavioral Disorders: Clinical Descriptions and Diagnostic Guidelines were published in 1993. (3) It proposed the collaborative project exploratory eye movements in patients with schizophrenia in 1989 and has promoted the project with the cooperation of six centers that included Beijing, Casablanca, Montreal, Munich, Prague and Sapporo. The findings of the present project indicated that exploratory eye movements may be specific to schizophrenia and can be practically used to discriminate schizophrenia without significantly depending on language.

Giant hepatic biloma following transcatheter oily chemoembolization in a patient with hepatic metastases from malignant pheochromocytoma

A 48-year-old woman developed hepatic metastases from malignant pheochromocytoma resected 8 years previously. Angiography revealed multiple tumor stains in the liver. Transcatheter oily chemoembolization using styrenomaleic acid neocarzinostatin and iodized oil was performed. The patient complained of severe right upper quadrant pain immediately following the transcatheter oily chemoembolization. Necrotizing cholecystitis developed on the 4th day post-transcatheter oily chemoembolization, hepatic infarction on the 12th day, and a biloma on the 19th day. Despite the administration of antibiotics and percutaneous transhepatic drainage, neither the volume of drainage nor the size of the biloma decreased. Biliary reconstruction was performed using a metallic stent, which decreased the size of the biloma.

Combined resection of abdominal aorta and inferior vena cava for retroperitoneal rhabdomyosarcoma invading the aortoiliac bifurcation

The authors report on an 11-year-old boy with retroperitoneal alveolar rhabdomyosarcoma at the aortoiliac bifurcation. The tumor was resected en bloc together with the infrarenal abdominal aorta and the inferior vena cava. The aortic defect was repaired successfully with a Y-shaped Dacron graft. The authors conclude that tumor resection with aortic reconstruction can be a choice for unresectable retroperitoneal tumors in children.

Effect of coronary bypass grafting onto the site of old myocardial infarction and the recovery of cardiac function

This study investigated whether or not revascularization to the site of old myocardial infarction can bring beneficial effects on postoperative cardiac function. Thirty-two patients without a history of old myocardial infarction and 71 with a history of old myocardial infarction were included. The mean number of grafts bypassed were 2.7 and 2.8, and the mean duration of aortic clamping was 99 min and 105 min in non-old myocardial infarction and old myocardial infarction patients, respectively. All the patients underwent simple coronary artery bypass grafting electively. The left ventricular stroke work index in non-old myocardial infarction and old myocardial infarction were 40.8 g-m/m2 and 38.9 g-m/m2 preoperatively, and this was recovered to 41.4 g-m/m2 and 38.7 g-m/m2, respectively, at 24 hours after reperfusion (NS). Subgroups of old myocardial infarctions had high ejection fractions of more than 50% (49) and low ejection fractions of less than 50% (22). The left ventricular stroke work index in high and low ejection fractions was 39.7 g-m/m2 and 36.7 g-m/m2 preoperatively (NS). Recovery rates in both high and low ejection fractions were reduced to 74.2% and 84.3% at 3 h after reperfusion (P < 0.001 and P < 0.05 versus preoperative value), but were increased in the low ejection fraction by up to 102.7% and 108.5% at 6 and 12 h after reperfusion, while still remaining reduced in the high ejection fraction at 88.8% and 88.2%, respectively (P < 0.01). At 24 h after reperfusion, left ventricular stroke work index in the low ejection fraction was improved to 44.3 g-m/m2 or 130% of the preoperative value, and the high ejection fraction was 37.5 g-m/m2 or 100% (NS). This showed that a chief cause of reduced cardiac function in the low ejection fraction was mainly reversible myocardial damage or hibernation. Preoperative mean left ventricular ejection fractions in non-old myocardial infarctions and old myocardial infarctions were 73.1% and 55.9%, and these returned to 73.7% (NS) and 61.8% (P < 0.001) at 1 month post-coronary artery bypass grafting. A similar trend towards a significant improvement was shown in both end-diastolic volume indices and end-systolic volume indices of patients with an old myocardial infarction (P < 0.001). Regional wall motion according to AHA classification in patients with old myocardial infarctions was estimated from biplane left ventriculogram as normal, reduced, none, dyskinetic and aneurysmal, and scored as 0, 1, 2, 3 and 4, respectively. Summated scores in old myocardial infarctions was improved from 5.2 to 4.1 after coronary artery bypass grafting (P < 0.05). There was a significant improvement of summated scores from 8.17 to 6.28 in the low ejection fraction (P < 0.05); however, this was not reflected in the high ejection fraction (3.76 to 3.0; NS). The regional wall motion in the old myocardial infarctions that were heart bypassed to the left anterior ascending artery (n = 67) or to the circumflex artery (n = 40) were significantly improved at regions 2 (P < 0.05), 3 (P < 0.05) and 7 (P < 0.05), and that bypassed to right coronary artery (n = 50) was also improved at regions 3 (P < 0.05), 5 (P < 0.05) and 7 (P < 0.001). This shows that augmentation of regional blood flow by coronary artery bypass grafting will contribute to awakening the hibernated myocardium even in the old myocardial infarction.

HLA class I and II alleles and susceptibility to generalized pustular psoriasis: significant associations with HLA-Cw1 and HLA-DQB1*0303

HLA alleles in generalized pustular psoriasis (GPP) were investigated to clarify the etiology and/or pathogenesis of this disease. Not only serological typing of HLA class I and II antigens but also genotyping of HLA class II alleles were carried out in twenty-six unrelated Japanese patients with GPP. These patients were classified according to their history of psoriasis vulgaris (PV). Serological typing revealed a significantly high incidence of HLA-Cw1 (Pc = 0.04) in the patients as compared with Japanese healthy controls. The frequency of HLA-B46 was particularly high in the patients with GPP and a previous history of PV. Genotyping of HLA class II alleles showed a highly significant increase in HLA-DQB1*0303 (Pc = 0.01) in the patients vs. the healthy controls. In particular, HLA-DQB1*0303 was significantly more frequent in the patients with no prior history of PV than in those with a history of PV. Analysis on linkage disequilibrium showed remarkably different patterns for HLA class II haplotypes between the patients and the healthy controls. Based on the comparative analysis among the amino acid sequences of the beta 1-domain of the HLA-DQB1*03 alleles, proline at residue 55 was suggested to be important as a common amino acid for determination of the susceptibility to GPP. These results revealed not only an association between the etiology and/or pathogenesis of GPP and HLA, but also different mechanisms of the immune response between the patients with GPP and PV.

Exploratory eye movement dysfunctions in patients with schizophrenia: possibility as a discriminator for schizophrenia

In our previous studies patients with schizophrenia and their parents had less frequent eye fixations and a more limited area of inspection than normal controls while freely viewing stationary S-shaped figures. The present study attempted to discriminate schizophrenics from non-schizophrenics using exploratory eye movements. Two groups (A and B) were formed, each comprising 30 schizophrenic and 70 non-schizophrenic subjects (10 each of patients with depression, methamphetamine psychosis, alcohol psychosis, anxiety disorder, temporal lobe epilepsy, frontal lobe lesions and healthy normal controls). Discriminant analysis was performed on group A to obtain a discriminant. The validity of applying this discriminant to group B was investigated. By focussing on exploratory eye movements, schizophrenics could be discriminated from non-schizophrenics with a sensitivity of 76.7% and a specificity of 81.4%. These results show that exploratory eye movements are a useful discriminator for schizophrenia.