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M Koga

Publications and source records attributed to M Koga.

At least 145 records · Page 8Linked to original sources
PubMed1999

Subclass distribution and the secretory component of serum IgA anti-ganglioside antibodies in Guillain-Barré syndrome after Campylobacter jejuni enteritis.

Previously, we reported that IgA anti-GM1 antibody is more closely associated with preceding Campylobacter jejuni enteritis in Guillain-Barré syndrome (GBS) than are IgG and IgM antibodies. However, the mechanism of the induction of IgA anti-ganglioside antibodies is not clear. In this study, serum IgA antibodies against GM1, GM1b, and GD1a, and GalNAc-GD1a were examined in 152 GBS patients. In GBS, antecedent C. jejuni infection is closely associated with IgA antibodies, other than GM1, against GM1b. The IgA subclass distribution is completely restricted to IgA1, no secretory IgA anti-ganglioside antibody being detected. This result does not support the hypothesis that the serum IgA antibodies present in GBS after C. jejuni enteritis originate at mucosal sites, such as the gut mucosal immune system. Seventeen (85%) of 20 patients with IgA anti-ganglioside antibodies had serological evidence of C. jejuni infection and/or a history of antecedent diarrhea. Moreover, a motor nerve conduction study showed that patients with IgA antibodies frequently had axonal neuropathy, whereas none had demyelinating neuropathy. This may support the previous report that IgA isotype anti-GM1 antibodies are more closely associated with poor outcome than are the IgG or IgM isotypes. The induction mechanism of IgA anti-ganglioside antibodies must be clarified by determining whether concentrations of cytokines, which increase the IgA class switch, are elevated in patients with GBS after C. jejuni enteritis.

Antibodies↗
PubMed1999

Autoantibodies to GM1b and GalNAc-GD1a: relationship to Campylobacter jejuni infection and acute motor axonal neuropathy in China.

IgG antibodies to the minor gangliosides GM1b and GalNAc-GD1a frequently are present in sera of Japanese patients with Guillain-Barré syndrome. The relationship between these autoantibodies and Campylobacter jejuni infection, the type of disease (acute motor axonal neuropathy [AMAN], or acute inflammatory demyelinating polyneuropathy [AIDP]) has yet to be established. Sera samples were obtained from 55 Chinese patients with clinically defined Guillain-Barré syndrome. An electrophysiology study showed nine AIDP, 28 had AMAN, and 18 unclassified. C. jejuni serology was positively correlated with anti-GM1b and anti-GalNAc-GD1a IgG antibodies (respective P values, 0.007 and 0.02). The frequencies of positive anti-GM1b and anti-GalNAc-GD1a serology were greater in AMAN (32 and 21%) than in AIDP (11 and 0%), but the differences were not significant. Infection by C. jejuni may induce IgG anti-GM1b antibody in some patients and IgG anti-GalNAc-GD1a antibody in others. A larger population of patients must be studied to show whether there is a definite correlation.

Acute Disease↗
PubMed1999

Antibodies to GD3, GT3, and O-acetylated species in Guillain-Barré and Fisher's syndromes: their association with cranial nerve dysfunction.

We examined serum antibodies to the four fetal antigens GD3, O-acetyl GD3, GT3, and O-acetyl GT3 ganglioside in patients with Guillain-Barré syndrome (GBS) or its variant Fisher's syndrome (FS). The patients with FS more often had significant IgG antibodies against GD3, GT3, and O-acetyl GT3 than did the healthy controls. Furthermore, anti-GD3 and anti-GT3 IgG antibodies were more often significantly present in the patients with FS than in those with GBS. IgG antibody to GD3, GT3, and O-acetyl GT3 had a significant association with the presence of ophthalmoparesis. These antibodies, however, cross-reacted with GQ1b and we detected no antibodies which specifically reacted with fetal gangliosides. In addition, oculomotor involvement was more closely related to IgG antibodies to GQ1b than to those to fetal gangliosides. No evidence was obtained that the serum antibodies to these fetal gangliosides are associated with specific neurologic signs of cranial nerves.

Cranial Nerve Diseases↗
PubMed1999

Are Campylobacter curvus and Campylobacter upsaliensis antecedent infectious agents in Guillain-Barré and Fisher's syndromes?

Campylobacter curvus and Campylobacter upsaliensis were isolated from stools of patients with Guillain-Barré (GBS) or Fisher's (FS) syndromes. Whether these microorganisms are pathogens of antecedent diarrhea in GBS and FS is not clear, therefore, we made a serological examination. There were no differences in antibody titer to these organisms among the patients with GBS, FS, and the controls. Some patients had elevated antibodies to the bacteria, but most also had serological evidence of C. jejuni infection. Moreover, the patients from whom C. curvus had been isolated did not have antibodies to the bacterium, indicative that they were healthy carriers of C. curvus or that the isolates were the product of contamination. We conclude that neither C. curvus nor C. upsaliensis is the major agent of antecedent diarrhea in GBS and FS.

Antibodies, Bacterial↗
PubMed1999

Axonal involvement at the common entrapment sites in Guillain-Barré syndrome with IgG anti-GM1 antibody.

If anti-GM1 antibody plays a role in the axonal damage in Guillain-Barré syndrome, the common entrapment sites may be preferentially involved with evidence of axonal dysfunction. To assess this hypothesis, we studied nerve conduction across the cubital tunnel in 44 patients. Abnormal amplitude reduction of compound muscle action potentials (CMAPs) was found in 45% of 20 immunoglobulin G (IgG) anti-GM1-positive and in 29% of 24 anti-GM1-negative patients. The time course and sequel were distinct between the two groups. In the former group, the amplitude reduction was prominent in weeks 1 to 2 and was followed by a decrease in distal CMAPs (axonal degeneration) or an increase in proximal CMAPs (resolution of conduction block). In contrast, anti-GM1-negative patients showed slower resolution with temporal dispersion. In anti-GM1-positive cases, amplitude reduction at the common entrapment site is frequent and may reflect wallerian degeneration or physiological conduction block at the nodes of Ranvier, both suggesting axonal involvement.

Action Potentials↗
PubMed1999

A study for the proper application of urinary naphthols, new biomarkers for airborne polycyclic aromatic hydrocarbons.

Urinary naphthols, 1- and 2-naphthol, recently have been suggested as route-specific biomarkers for exposure to airborne polycyclic aromatic hydrocarbons. For the proper application of urinary naphthols as biomarkers, we studied effects of lifestyle on urinary naphthols levels in 119 Japanese male workers. After improving the detection limit of urinary naphthols up to 0.27 microg/L by high-resolution capillary gas chromatography/mass spectrometry/selected ion monitoring, urinary naphthols were detectable in approximately 90% of the subjects. Among detectable samples, the geometrical mean (GM) of urinary 1-naphthol concentration was 5.13 microg/L (geometrical standard deviation, GSD, 4.90), while the GM of urinary 2-naphthol concentration was 3.16 microg/L (GSD, 5.61). We observed that urinary 1- and 2-naphthol level were three- and sevenfold higher, respectively, among smokers than among nonsmokers (p < 0.01). The ratios of urinary 2-naphthol to 1-naphthol were significantly higher among smokers than nonsmokers (p < 0.05). The number of cigarettes smoked and urinary cotinine levels were also positively related to the concentration of urinary naphthols (p < 0.01), while other lifestyle factors, i.e., age and consumption of alcohol, greasy or salty food, sweets, fruits, vegetables, meat, or fish, were not. We also studied whether genetic polymorphisms of enzymes, which were involved in naphthalene metabolism, affected urinary naphthols levels. The cytochrome P450 (CYP) 1A1 exon 7 genetic polymorphism was not related to urinary naphthol levels. Among smokers, the subjects with c1/c2 or c2/c2 type of CYP2E1, which was determined by CYP2E1 RsaI polymorphism in 5'-flaking region, showed higher concentrations of urinary 2-naphthol than the subjects with c1/c1 type regardless of creatinine-correction (p < 0.05) and the subjects with glutathione S-transferase (GST) M1 deficient type showed higher concentrations of both urinary 1- and 2-naphthol than those with GSTM1 normal type but only without creatinine-correction (p < 0.05). Thus, when urinary naphthols are used as biomarkers, smoking and the genetic polymorphisms of CYP2E1 and GSTM1 should be considered.

Adult↗
PubMed1999

Strongyloides ratti: additive effect of testosterone implantation and carbon injection on the susceptibility of female mice.

A sex-related difference in host susceptibility to Strongyloides ratti was previously known. Male mice were more susceptible to S. ratti infection and the difference was seen against migrating larvae under the regulation of testosterone. Against migrating larvae, macrophages were assumed to play important roles in host natural immunity. On the basis of these findings, to examine the effect of testosterone on macrophages we treated female mice with testosterone and/or carbon to block the function of macrophages. Mice were then infected with third-stage larvae of S. ratti. By counting of the migrating larvae in the cranial cavity at 36 h after infection the effect of each treatment was assayed. Testosterone treatment alone (Te) or carbon injection alone (Ca) effectively increased the worm recovery. Given together, Te and Ca (Te + Ca) significantly increased the worm recovery to levels almost equal to the sum of those achieved with Te and Ca. The serum testosterone concentration was elevated in mice that had undergone Te and Te + Ca at the time of worm recovery. Surprisingly, the serum testosterone concentration reached after Te + Ca was elevated more than that attained by Te. The same experiment with a half-dose of Te and Ca (Te half + Ca) resulted in the same testosterone concentration achieved with Te and resulted in a worm recovery almost equal to the sum of that achieved with Te and Ca. These results clearly showed that Te and Ca had an additive effect on the recovery of migrating S. ratti larvae. Testosterone had an effect after macrophages had been blocked. The relationship between testosterone and macrophage function during S. ratti infection is discussed.

Animals↗
PubMed1999

Clinical features of 89 patients with autoimmune hepatitis in Nagasaki Prefecture, Japan.

We examined the clinical characteristics of 89 patients with autoimmune hepatitis (AIH) in Nagasaki Prefecture, Japan, and assessed the usefulness of a provisional scoring system for the diagnosis of AIH proposed by the International Autoimmune Hepatitis Group in 1993. The majority of patients were middle-aged women in their fifties. All patients showed a hepatitic picture. Forty-three patients (48%) had an insidious or chronic onset, while 34 (38%) had an acute onset, and 12 (14%) had liver cirrhosis at presentation. Seventy-nine patients (89%) were positive for antinuclear antibody (ANA), and 5 (6%) were positive for antibody to the hepatitis C virus (anti-HCV). The prognosis was good, with 90% 3-year survival, and most patients responded well to treatment with corticosteroids. The international scoring system was useful for the diagnosis of AIH in most of our patients; the percentages of patients with definite and probable AIH were 48% and 47%, respectively. However, certain factors, such as negative ANA, positive antimitochondrial antibody, concurrent infection with hepatitis B or C virus, and insufficient response to treatment precluded the diagnosis of AIH in some patients. Whether these patients were indeed "true" AIH patients is not clear at present, and further investigation of such patients may be useful for a better understanding of AIH.

Adolescent↗
PubMed1999

Immunohistochemical analysis of hepatic interferon alpha-beta receptor level: relationship between receptor expression and response to interferon therapy in patients with chronic hepatitis C.

BACKGROUND/AIMS: This study aimed to determine the expression level of interferon alpha/beta (IFN-alpha/beta) receptor in the liver immunohistochemically and evaluate its usefulness in predicting the outcome to IFN therapy in patients with chronic hepatitis C. METHODS: The level of IFN-alpha/beta receptor expression was determined in immunoperoxidase-stained pretreatment sections of 55 chronic hepatitis C patients later treated with IFN. We used liver biopsy specimens and mouse monoclonal anti-human IFN-alpha/beta receptor antibody. Quantitative analysis of immunostaining was performed by image analysis software. The level of IFN-alpha/beta receptor was expressed as Unit (U). Sustained responders were patients who showed persistent disappearance of serum HCV-RNA during the 6-month period after treatment, while non-responders showed persistence of viremia after therapy. RESULTS: Positive immunostaining was observed in the cytoplasm of hepatocytes. The mean expression level of hepatic IFN-alpha/beta receptor in sustained responders (2.65+/-1.11 U, n = 15) was significantly (p<0.001) higher than in non-responders (1.61+/-1.05 U, n = 40). A significant decrease in IFN-alpha/beta receptor expression level was observed in patients with advanced liver fibrosis. In patients with low level viremia (pretreatment serum HCV-RNA <1 Meq/ml, n = 18), the level of IFN-alpha/beta receptor in sustained responders (2.89+/-1.12 U, n = 11) was significantly (p<0.01) higher than in non-responders (0.93+/-0.33 U, n = 7). CONCLUSIONS: Our results suggest that measurement of the level of hepatic IFN-alpha/beta receptor in patients with chronic hepatitis C might be useful for predicting the response to IFN therapy. Resistance to IFN therapy in patients with chronic hepatitis C might be due to low levels of hepatic IFN-alpha/beta receptor.

Adult↗
PubMed1999

Prevalence and clinical characteristics of TT virus (TTV) in patients with sporadic acute hepatitis of unknown etiology.

BACKGROUND/AIMS: Recently, a novel DNA virus was isolated from the serum of a patient with post-transfusion non-A-G hepatitis and named TT virus. The aim of this study was to determine the prevalence and clinical characteristics of TT virus infection in patients with sporadic acute hepatitis of unknown etiology. METHODS: TT virus was investigated in the serum of 66 patients with sporadic acute hepatitis non-A-G and 50 healthy controls by semi-nested PCR with previously published primers. RESULTS: TT virus was detected in 17 (26%) of the 66 patients with sporadic acute hepatitis non-A-G and in a slightly higher rate (34%,17/50) in the control group. No significant differences in alanine aminotransferase or bilirubin concentrations were observed between the groups of patients with or without TT virus infection. Eighty per cent (12/15) of patients for whom follow up was possible had persistent viremia from 4 to 36 months, and 67% (8/12) of these patients had already normalized their levels of alanine aminotransferase. A phylogenetic tree constructed by the Neighbor Joining Method revealed that all isolates in this study were grouped within genotype 1a and 1b, without showing any association between genetic type and development of hepatic disease. CONCLUSIONS: Our results suggest that TT virus DNA is present not only in patients with sporadic acute hepatitis non-A-G but also in a large proportion of the general population. This virus was not likely to be the causative agent of hepatitis among the patients in this study.

Acute Disease↗
PubMed1999

A keyword search system for medical doctors to introduce their patients to specialists.

We developed an online keyword search system on a WWW server to help medical doctors to introduce their patients to specialists. The system stores special knowledge and advanced techniques of 287 medical specialists in Kyushu University Hospital. The data set was presented by the medical specialists themselves. Specialists can rewrite their data set using the browser anytime to keep their data set up to date. In addition, the specialists are reminded to keep their data set up to date by direct mail once a year. The system does not use any database management systems. We used only two text files and the "grep" command, one of the basic commands of the UNIX system. Then, it takes less than 1 sec to search one medical specialist's data set from 200 specialists' data sets. The system is useful not only inside the hospital but also for practitioners in the local area.

Humans↗
PubMed1999

Decreased interferon-gamma (IFN-gamma)-producing T cells in patients with acute Kawasaki disease.

Kawasaki disease (KD) is an acute febrile illness of early childhood, in which the activation of monocytes/macrophages plays a central role in the development of vasculitis during the acute stage of disease. In this study we investigated peripheral blood T cells of 10 patients with KD, focusing on the Th1 and Th2 imbalance, using intracellular cytokine staining and analysis of the cytokine-producing T cells by flow cytometry. We observed a decrease in the numbers of IFN-gamma-producing, but not IL-4-producing, CD3+ T cells, during the acute stage. Our results suggest that there is an imbalance of Th1 and Th2 subsets during the acute stage of KD.

CD3 Complex↗
PubMed1999

Prolonged nocturnal penile tumescence caused by epinastine.

PURPOSE: We report a case of prolonged nocturnal penile tumescence (NPT) caused by the antiallergic agent epinastine. METHODS/RESULTS: We measured NPT using Rigiscan-Plus (DacoMed, Minneapolis, MN, USA) with or without the patient having taken epinastine. CONCLUSIONS: Considering its pharmacological effects on cyclic nucleotides, epinastine may have an effect on erectile function.

Dibenzazepines↗
PubMed1999

Experimental His-bundle pacing: histopathological and electrophysiological examination.

His-bundle pacing gives a more physiological ventricular contraction in comparison to right ventricular apical pacing. However the problems of lead fixation and stability of long-term His-bundle pacing are yet unsolved. We used six adult beagles, in which a screw-in lead was anchored in the His-bundle region for observation of the pacing conditions and histopathologic changes of the conduction system over the course of 2 months. In the results, a satisfactory fixation was obtained using a conventional screw-in lead and no histological influence on the conduction system was observed. The pacing threshold at the time of implantation was 1.15 +/- 0.69 V (3.23 +/- 3.08 mA) in the pulse width of 0.5 ms. R wave amplitude, the impedance and slew rate were 7.28 +/- 2.04 mV, 409 +/- 102 Ohm, and 0.65 +/- 0.41 V/s, respectively. Two months later, these parameters changed to 2.83 +/- 1.06 V (10.4 +/- 5.71 mA), 5.63 +/- 1.62 mV, 310 +/- 71.3 Ohm, and 0.49 +/- 0.22 V/s, respectively. These results suggest the feasibility of clinical application of permanent His-bundle pacing.

Animals↗