Biomedical subjects
Publications and source records attributed to Masayuki Nakano.
Although intracerebral haemorrhage occurring after surgery for chronic subdural haematoma has been reported as a rare complication, intracerebral haemorrhage occurring during surgery has not been described previously. A case of bilateral chronic subdural haematomas, with a small motor area haemorrhage occurring intra-operatively, is described here.
BACKGROUND: We sometimes encounter hepatocellular carcinoma (HCC) with a central scar and a scalloped tumor margin resembling focal nodular hyperplasia (FNH) in macroscopic appearance. The fibrolamellar variant sometimes shows this appearance; however, this type of HCC can be clearly differentiated from fibrolamellar variants on the basis of clinical and histopathological findings. The clinical features of patients with this type of HCC need to be clarified. METHODS: From 1988 to 1999, 1,043 patients with HCC underwent hepatectomy at our institution. Histopathological examinations show that fibrolamellar HCC was not included in the series. We selected HCC with a central scar and a scalloped tumor margin resembling FNH in macroscopic appearance. We refer to such tumors as scalloped HCC. We compared the clinical findings and surgical outcomes between patients with scalloped HCC and patients with simple nodular HCC. RESULTS: Of the 1,043 cases of HCC, 31 (3%) and 571 (55%) were scalloped HCC and simple nodular HCC, respectively. The mean age of the patients with scalloped HCC was 60.7 years, and that of the patients with simple nodular HCC was 62.6 years, without significant difference. The rates of hepatitis C virus infection and liver cirrhosis and serum alpha-fetoprotein levels were significantly lower, and Child-Pugh class and surgical outcomes were significantly better in patients with scalloped HCC than in those with simple nodular HCC. In multivariate analysis, Child-Pugh class (P < 0.001), tumor size (P = 0.046), and gross appearance (P = 0.009) were independent significant prognostic factors. CONCLUSION: HCC with a central scar and a scalloped tumor margin resembling FNH occurs in non-cirrhotic patients in their 60s and is associated with a good surgical outcome.
The chemical compound [4-(4-bromo-2-cyano-phenylcarbamoyl)-benzyl]-phosphonic acid diethyl ester (NO-1886) is a lipoprotein lipase activator having beneficial effects on both diabetes control and the cardiovascular system. Preventing accumulation of lipids in the cell wall, in addition to improving insulin actions on vasculature, may indirectly contribute to the reducing effect of NO-1886 on vascular resistance. However, the direct effect of NO-1886 on vascular resistance, i.e., whether NO-1886 directly modulates the function of vascular endothelium and/or smooth muscle cells has not been investigated. In this study we therefore investigated the direct effect of NO-1886 on vascular contractility using rat aortic rings and cultured smooth muscle cell-line A10. The results show that administration of NO-1886 attenuated aortic contraction induced by phenylephrine and/or a high K(+) environment, in both the presence and absence of aortic endothelium. 1-(5-Chloronaphthalene-1-sulfonyl)homopiperazine hydrochloride (ML-9), a myosin light chain kinase (MLCK) inhibitor, blocked this inhibitory effect of NO-1886, whereas inhibitors of other signaling molecules such as calmodulin, protein kinase C and Rho-kinase had no effect. The vasorelaxant effect of NO-1886 was blocked in the absence of extracellular Ca(2+), or in the presence of the Ca(2+) channel inhibitor, verapamil. NO-1886 attenuated smooth muscle contraction induced by the cumulative addition of CaCl(2). In A10 cells, NO-1886 inhibited the membrane depolarization-induced initial peak of [Ca(2+)](i) in the presence of extracellular Ca(2+). This inhibition did not occur in the absence of extracellular Ca(2+). Taken together these results demonstrate that NO-1886 attenuates smooth muscle contraction and causes vasorelaxation by an extracellular Ca(2+)- and MLCK-dependent mechanism.
Haemolysin (VMH) is a virulent factor produced by Vibrio mimicus, a human pathogen that causes diarrhoea. As intestinal epithelial cells are the primary targets of haemolysin, we investigated its effects on ion transport in human colonic epithelial Caco-2 cells. VMH increased the cellular short circuit current (Isc), used to estimated ion fluxes, and 125I efflux of the cells. The VMH-induced increases in Isc and 125I efflux were suppressed by depleting Ca2+ from the medium or by pretreating the cells with BAPTA-AM or by Rp-adenosin 3',5'-cyclic monophosphorothioate triethylammonium salt (Rp-cAMPS). The Cl- channel inhibitors 4,4'-disothiocyanatostibene-2,2'-disulfonic acid (DIDS), glybenclamide, and 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB) suppressed the VMH-induced increases in Isc and 125I efflux. Moreover, VMH increased the intracellular concentrations of Ca2+ and cAMP. Thus, VMH stimulates Caco-2 cells to secrete Cl- by activating both Ca2+ -dependent and cAMP-dependent Cl- secretion mechanisms. VMH forms ion-permeable pores in the lipid bilayer that are non-selectively permeable to small ions. However, the ion permeability of these pores was not inhibited by glybenclamide and DIDS, and VMH did not change the cell membrane potential. These observations indicate that the pores formed on the cell membrane by VMH are unlikely to be involved in VMH-induced Cl- secretion. Notably, VMH stimulated fluid accumulation in the iliac loop test that was fully suppressed by a combination of DIDS and glybenclamide. Thus, Ca2+-dependent and cAMP-dependent Cl- secretion may be important therapeutic targets with regard to the diarrhoea that is induced by Vibrio mimicus.
A novel murine glycerol-3-phosphate acyltransferase-like protein 1 (named xGPAT1) has been cloned. The mouse xGPAT1 gene is located on mouse Chromosome 2, spans >19 kb, and consists of at least 23 exons. The protein is 32% identical and 72% similar to mouse mitochondrial GPAT (mtGPAT) on the amino acid level. Sequencing analysis confirmed that xGPAT1 has a 2403-bp open reading frame (ORF) that encodes an 801-amino acid protein with an estimated molecular mass of 89.1 kDa. A hydropathy plot of the deduced xGPAT1 protein showed a high degree of similarity with that of the mtGPAT protein. Using 5'-rapid amplification of cDNA ends, two alternate, untranslated exon 1 (1a and b) isoforms were obtained, generating variants xGPAT1-v1 and xGPAT1-v2. xGPAT1-v1 is expressed in mouse heart, liver, spleen, kidney and murine inner medullary collecting duct 3 (mIMCD3) cells, while xGPAT1-v2 is expressed in mouse liver, spleen, kidney, white and brown adipose tissues and 3T3-L1 pre- and post-adipocytes. xGPAT1 was distributed in the membrane fraction and showed GPAT activity when epitope-tagged xGPAT1 was expressed in Chinese hamster ovary (CHO)-K1 cells.
Explore the source record for details and available documents.
BACKGROUND: Some patients who are seropositive for lectin-reactive alpha-fetoprotein (AFP-L3) have intrahepatic cholangiocarcinoma (ICC). There have been no studies regarding the features of ICC patients seropositive for AFP-L3. Thus, the purpose of the present paper was to compare the features of ICC patients from the viewpoint of two different tumor markers, AFP-L3 and carbohydrate antigen (CA) 19-9. METHODS: The ICC patients who underwent hepatectomy (n = 51) were divided into three groups, and their clinicopathologic features were compared: (i) group A, seropositive for AFP-L3 >or= 15%; (ii) group B, seropositive for CA 19-9 >or= 37 U/mL; and (iii) group C, seronegative for both AFP-L3 and CA 19-9. The features of combined hepatocellular and cholangiocarcinoma (n = 11) were also studied. RESULTS: Group A had a higher positivity rate for hepatitis viruses than group B (60%vs 20%, P < 0.05). More patients in group A were misdiagnosed as having hepatocellular carcinoma (HCC) at surgery (70%vs 5.7%, P < 0.001) who also had chronic liver disease (80%vs 25.7%, P < 0.01) than in group B. Seven, 10 and 11 of the 11 patients with combined hepatocellular and cholangiocarcinoma were seropositive for AFP-L3, CA 19-9 and hepatitis viruses, respectively. Ten were diagnosed as having HCC at surgery and nine had chronic liver disease. CONCLUSIONS: Patients with ICC seropositive for AFP-L3 and those with combined hepatocellular and cholangiocarcinoma have features close to HCC. The present study has, for the first time, identified a subgroup of ICC patients, seropositive for AFP-L3, having features close to HCC that are very different from those of the classical ICC patients seropositive for CA 19-9.
BACKGROUND: Phylogenetic analysis has been used widely to characterize extraintestinal pathogenic Escherichia coli in molecular epidemiological studies. We have recently reported a putative pathogenicity island (PAI), carrying uropathogenic-specific protein (usp) and a unique mosaic structure of small open reading frames following usp, providing four subtypes of PAIusp classified from their sequential patterns. METHODS: A total of 427 E. coli isolates from uncomplicated urinary tract infections (194 cystitis, 76 pyelonephritis, and 107 prostatitis) and 50 fecal isolates were examined for phylogenetic grouping and PAIusp subtyping as well as the prevalence of virulence factors (VF) and O serogroups. RESULTS: Both phylogenetic group B2 and usp-positive strains were equally predominant in cystitis, pyelonephritis and prostatitis (B2, 80.9%, 86.8%, and 86.9%; usp, 79.4%, 93.4%, and 88.8%, respectively). Furthermore, each PAIusp subtype was shown to be closely associated with several VF genes as well as several common O serogroups of uropathogenic E. coli. CONCLUSIONS: In molecular epidemiological studies, PAIusp subtyping will provide additional informative findings of E. coli strains belonging to phylogenetic group B2.
Aeromonas sobria hemolysin (ASH) is one of the major virulence factors produced by A. sobria, a causative agent of diarrhea in humans. We investigated the effects of ASH on anion transport in human colonic epithelial cells. ASH increased short circuit currents across the intestinal epithelia, which were suppressed by anion channel antagonists, such as carbonic anhydrase inhibitors, and by the removal of external HCO3-. Iliac fluid accumulation was also inhibited by carbonic anhydrase inhibitors. The results suggest that ASH activates HCO3- secretion, whose level correlates with the severity of diarrhea.
Explore the source record for details and available documents.
The induction of oxidative stress in pulmonary cells during the process of lung tumor promotion by dimethylarsinic acid (DMA), a main metabolite of inorganic arsenics in mammals, was examined by immunohistochemical analysis using a specific antibody against 4-hydroxy-2-nonenal (4HNE) adducts, which are major aldehydic metabolites of lipid peroxidation. We demonstrated that 4HNE-modified proteins existed specifically in the secretory granules in terminal bronchiolar Clara cells. Furthermore, the degree of positive staining increased with the duration of DMA administration. Transmission electron microscopy revealed morphological changes in the Clara cells of DMA-treated mice. These results suggest that Clara cells are the major target cell for DMA-induced oxidative stress and that the cells may play an important role in the lung tumor promotion process in mice.
We examined the histological findings of non-alcoholic steatohepatitis (NASH) and ALD to study resemblance and difference of these two diseases. At a glance of H&E staining, they looked same, however, careful examination on silver impregnation histology, the fibrosis of NASH showed lattice fibrosis on the other hand ALD showed solid fibrosis. The appearance of fibrosis was different due to qualitative difference. More examination on the change of hepatocytes, there were some difference in incidence of the findings such as megamitochondria, bile stasis, hemosiderin deposition, vacuolic nuclei, and lipogranuroma. So we are able to differentiate NASH and ALD histologically.
We investigated the relationship between lung- and skin-tumor promotion and oxidative stress caused by administration of dimethylarsinic acid (DMA(V)) in mice. The incidence of lung tumors induced by lung tumor initiator (4NQO) and DMA(V) were, as well as 8-oxo-2'-deoxyguanosine (8-oxodG), suppressed by cotreatment with (-)epigallocatechin gallate (EGCG). When mice were topically treated with trivalent dimethylated arsenic (DMA(III)), a further reductive metabolite of DMA(V), not only an increase in skin tumors but also an elevation of 8-oxodG in epidermis were observed. These results suggest that tumor promotion due to DMA(V) administration is mediated by DMA(III) through the induction of oxidative stress.
The stereocontrolled total synthesis of a C31-allenic apo-carotenoid, paracentrone, was achieved by the convergent C20 + C11 = C31 strategy. The key elements of our synthesis were the Pd-catalyzed cross-coupling to stereoselectively construct the conjugated polyene backbone skeleton and the designed geometrical isomerization at the central double bond of the conjugated polyene chain. In addition, the terminal oxygenated cyclohexane ring having the allenic moiety was prepared by the highly diastereoselective Sharpless epoxidation under our own reaction conditions.
Aeromonas sobria hemolysin (ASH) is one of the major virulence factors produced by A. sobria, a human pathogen that causes diarrhea. We investigated the effects of ASH on Cl(-) transport in human colonic epithelial cells. ASH increased short-circuit currents (Isc) and (125)I efflux from Caco-2 cells, indicating ASH activate Cl(-) secretion. Additions of inhibitors of cyclic AMP dependent Cl(-) channels, glybenclamide and NPPB suppressed the Isc and (125)I efflux increases induced by ASH. And ASH increased the intracellular cyclic AMP concentration. Moreover, ASH stimulated fluid accumulation in the iliac loop test, and glybenclamide and NPPB suppressed this fluid accumulation. Thus, cAMP-dependent Cl(-) secretory pathway could be related with diarrhea induced by A. sobria.
BACKGROUND: Primary biliary cirrhosis (PBC) is histopathologically characterized by chronic nonsuppurative destructive cholangitis and ductopenia of interlobular bile ducts. Bile duct injury is also often encountered in chronic viral hepatitis (CVH) and in autoimmune hepatitis (AIH). METHODS: In this study, we performed interobserver agreement analysis on 90 injured bile ducts from liver specimens of PBC (17 cases), CVH (26 cases), and AIH (18 cases), with 30 bile ducts chosen from each disease group. Digital images of bile ducts with minimal periductal elements were recorded in CD-ROM format and sent to 14 observers (six special hepatopathologists, four local hepatopathologists, and four general pathologists). We analyzed the following issues: (1) diagnostic accuracy of PBC, based only on bile duct lesions; (2) classification of bile duct lesions in AIH cases as destructive cholangitis equivalent to PBC-associated injury, or not. RESULTS: The diagnostic accuracy of PBC cases with severe bile duct injuries was very high (over 80%), although the accuracy in cases with only mild bile duct injuries was low (50% or less). For AIH, each observer classified 9 of the 30 bile ducts, on average, as destructive cholangitis. CONCLUSIONS: This study revealed that 66.9% of PBC cases could be diagnosed based on trimmed bile ducts alone. Bile duct injury similar to that in PBC could be encountered in AIH.
Bacteria produce many types of hemolysin that induce diarrhea by mechanisms that are not completely understood. Aeromonas sobria hemolysin (ASH) is a major virulence factor produced by A. sobria, a human pathogen that causes diarrhea. Since epithelial cells in the intestine are the primary targets of hemolysin, we investigated the effects of ASH on ion transport in human colonic epithelial (Caco-2) cells. ASH increased short-circuit currents (Isc) in a dose-dependent manner, and it also activated a 125I efflux from Caco-2 cells. ASH-induced Isc increases and 125I efflux activations were both suppressed by low Ca2+ levels in the extracellular solution or by pretreatment with the Ca2+ chlelator BAPTA-AM. Intracellular Ca2+ levels were increased by ASH in a biphasic fashion characterized by a rapid sharp increase (peak 1) followed by a sustained low plateau (peak 2). ASH-induced peak 1 was inhibited by pretreatment with pertussis toxin, indicating that Ca2+ was mobilized from intracellular stores, and peak 2 was induced by an influx of extracellular Ca2+. Peak 2 but not peak 1 was related to Cl- secretion. These results indicate that ASH activates Ca2+-dependent Cl- secretion.
Rapid resolution of acute subdural haematoma (ASDH) has rarely been observed. Two elderly patients with rapid resolution of ASDH are described. In the present cases, it was indicated that a mechanism of rapid resolution of ASDH was attributable to cerebrospinal fluid dilution and cerebral atrophy resulting from aging.