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H Obata

Publications and source records attributed to H Obata.

At least 127 records · Page 7Linked to original sources
PubMed1994

The risk factor for development of thyroid disease during interferon-alpha therapy for chronic hepatitis C.

OBJECTIVES: To determine the risk factors for the development of thyroid diseases during interferon-alpha therapy, we analyzed the patients with chronic hepatitis C who were treated with interferon-alpha. METHODS: One hundred nine patients with chronic hepatitis C (77 men and 32 women, ages 20-72 yr) were treated with interferon-alpha (alpha, 48; alpha 2a, 38; alpha 2b, 23) for 14-40 wk. Thyroid function tests and seven autoantibodies were assessed at the beginning and end of interferon-alpha therapy, and every other month. A logistic multiple regression model was used in the statistical analysis of risk factors for development of thyroid diseases. RESULTS: Among the 106 patients with normal pretreatment thyroid function tests, nine patients (three men and six women, ages 33-62 yr) developed thyroid diseases. However, among three patients with abnormal thyroid function tests, exacerbation of thyroid disease was not observed during interferon-alpha therapy. Logistic multiple regression model revealed that positivity for microsome antibody was a significant risk factor for the development of thyroid disease (p < 0.0001, chi 2 = 20.18). Actually, compared to patients without microsome antibody at the beginning of therapy, the incidence of thyroid diseases in the patients with pretreatment microsome antibody was very high: 3.3% (3/99) versus 60% (6/10), respectively. Six patients developed hyperthyroidism and three patients developed hypothyroidism. The patients with hyperthyroidism had atypical clinical features. CONCLUSION: Our study revealed that positivity for microsome antibody at the beginning of interferon-alpha therapy is a risk factor for thyroid dysfunction.

Adult↗
PubMed1993

Aromatization of 4-oxocyclohexanecarboxylic acid to 4-hydroxybenzoic acid by two distinctive desaturases from Corynebacterium cyclohexanicum. Properties of two desaturases.

We have previously demonstrated that Corynebacterium cyclohexanicum degrades cyclohexanecarboxylic acid, a bacteriocide, through a pathway including the aromatization of 4-oxocyclohexanecarboxylic acid to 4-hydroxybenzoic acid [Kaneda, T. (1974) Biochem. Biophys. Res. Commun. 58, 140-144]. Aromatization has now been shown to be catalysed by two desaturase enzymes. Under the action of desaturase I, 4-oxocyclohexanecarboxylic acid is converted to (+)-4-oxocyclohex-2-enecarboxylic acid which is then aromatized by desaturase II to 4-hydroxybenzoic acid. The latter reaction is presumed to occur via the unstable intermediate, 4-oxocyclohex-2,5-dienecarboxylic acid, which is spontaneously isomerized to 4-hydroxybenzoic acid. Desaturase I has been purified in an electrophoretically homogeneous form. It is monomeric with a molecular mass of 67 kDa and contains one tryptophan, one histidine and two cysteine residues per enzyme molecule. The enzyme produces an equivalent amount of 4-oxocyclohex-2-enecarboxylic acid and hydrogen peroxide from 4-oxocyclohexanecarboxylic acid. The properties of desaturase I have been studied in detail. Desaturase II is unstable and has been partially purified. Its characterization is therefore limited. However, the molecular mass of desaturase II was estimated to be 43 kDa by gel filtration chromatography. The characterization of both desaturase enzymes is described in this paper. The possible environmental importance of microbial aromatization in the biodegradation of compounds with the cyclohexane structure is discussed.

Amino Acids↗
PubMed1993

Hepatitis C virus antibody in patients with primary liver cancer (hepatocellular carcinoma, cholangiocarcinoma, and combined hepatocellular-cholangiocarcinoma) in Japan.

BACKGROUND: In hepatocellular carcinoma (HCC), a high prevalence of hepatitis C virus antibody (anti-HCV) has been reported, indicating that it may be an important etiologic factor in the pathogenesis of HCC. In this study, the authors investigated the prevalence of anti-HCV in HCC patients, as well as the same prevalence in patients with cholangiocarcinoma (CC) and combined hepatocellular-cholangiocarcinoma (combined HCC-CC), to study the clinicopathologic features of anti-HCV-positive cases. METHODS: The authors examined 141 patients with primary liver cancer who were pathologically diagnosed as having HCC (121 cases), CC (13 cases), or combined HCC-CC (7 cases). Hepatitis B surface antigen (HBsAg) and anti-HCV were measured in these patients. RESULTS: Of 121 HCC cases, 85 (70.3%) were found to be anti-HCV positive, 16 (13.2%) were HBsAg positive, and 5 (4.1%) were both anti-HCV and HBsAg positive. In 13 cases with CC and in 7 with combined HCC-CC examined, 4 (30.8%) and 5 (71.4%), respectively, were anti-HCV positive. CONCLUSIONS: The anti-HCV-positive rate was high in combined HCC-CC as well as in HCC. These three types of primary liver cancer, which were anti-HCV positive, shared two common features: male dominance and high incidences of complication with liver cirrhosis.

Adenoma, Bile Duct↗
PubMed1993

Serum and gastric mucosal pepsinogens in atrophic gastritis, particularly in type A gastritis associated with pernicious anemia in Japanese.

The levels of serum pepsinogen I (PG I) and pepsinogen II (PG II) were determined by IRMA (immunoradiometric assay) and the ratio of PG I/II calculated in 37 patients with type A gastritis and concomitant pernicious anemia (PA) and in 97 with chronic gastritis (type B gastritis) among Japanese. In several patients from each group, PG I and PG II in the gastric mucosa were stained by an enzyme antibody assay to compare the percentage of positively stained cells with levels of serum PG I and PG II. The levels of serum PG I and PG II in chronic gastritis decreased as the degree of atrophy increased. Serum PG I and PG II levels in PA were lower than those of patients with severe atrophy. Most of serum PG I levels in PA were less than 10 ng/ml. The PG I/II ratio also decreased as the severity of atrophy increased, distinctly showing that in PA, the ratio were quite low and most of them are less than 1.0. Gastric mucosal pepsinogen showed a tendency similar to that of serum levels and also refrected the degree of atrophy. Therefore, by measuring these parameters it should be easier to determine the extent of atrophy, and to establish a serological diagnosis of type A gastritis associated with PA.

Anemia, Pernicious↗
PubMed1993

Possible role of preS2 peptides presented by MHC class I antigen in the pathogenesis of chronic hepatitis B.

Many variations exist in the first 39 nucleotides of the preS2 (pre-S2; 1-39) region of the HBV genome. Based on the similarities of their coding amino acid sequences to those of prototype HBV, they were classified into 3 different types, adr-preS2, adw-preS2 and ayw-preS2. To clarify the meaning of these variabilities in the preS2 region, we studied the HLA class I phenotype of chronic hepatitis B patients having high levels of serum ALT. Our results indicated that in 12 of 14 chronic hepatitis patients infected with HBV type adr-preS2 had HLA-A24 phenotype whereas all of 7 patients infected with either adw- or ayw-preS2 HBV had HLA-A2 phenotype. This strong association between HLA class I phenotype and certain preS2 types of HBV infection was found only in patients with high serum ALT levels but not in patients with almost normal levels of serum ALT. Our results therefore suggest that in the generation of chronic hepatitis B a suitable combination between a fragment of preS2 antigen and HLA class I antigens of the infected host, such as adr-preS2 with HLA-A24 and either adw- or ayw-preS2 with HLA-A2, might be required.

Base Sequence↗
PubMed1993

Idiopathic portal hypertension; a histopathological study of 26 Japanese cases.

Analysis of 25 liver biopsy specimens and one autopsy specimen from 26 Japanese patients (23 women and three men) with idiopathic portal hypertension revealed findings that collectively appeared diagnostic for the condition. Changes in the portal tract included capillary dilatation, phlebosclerosis, and fibro-elastosis of the stroma. Many portal veins were dilated and had herniated into the surrounding hepatic parenchyma. Portal vein obliteration and loss of bile ducts were a rare complication. The acinar architecture was disturbed by: 1) capillary and necro-inflammatory bridging, mostly between portal tracts and terminal hepatic veins; 2) the formation of isolated megasinusoids in a random distribution; 3) displaced and abnormally large hepatic vein branches with or without phlebosclerosis and 4) slender, curved fibrous septa (hairline septa). Early nodular regeneration was found in 25% of the cases. Our review supports the contention that incomplete septal cirrhosis may be a late manifestation of idiopathic portal hypertension. It is not clear whether the biopsy findings in Japanese patients differ only in severity from those in western patients, or whether the conditions differ pathogenetically. Some histopathological findings in the Japanese cases, in particular the necro-inflammatory changes, are difficult to reconcile with portal hypertension as a primary haemodynamic abnormality.

Adult↗
PubMed1993

Liver biopsy features of acute hepatitis C compared with hepatitis A, B, and non-A, non-B, non-C.

The diagnosis of acute hepatitis C (AHC) often can only be suspected because current serologic tests remain negative for over 3 months. Because histologic features might provide useful clues, we reviewed 85 liver biopsy specimens from 85 patients with acute viral hepatitis, comparing 22 cases of AHC with 23 cases of acute hepatitis A (AHA), 30 cases of acute hepatitis B (AHB), and 10 cases of acute hepatitis non-A, non-B, non-C (AHNC). AHC was characterized by dense portal lymphoid aggregates (7 cases) and Poulsen-Christoffersen-type cholangitis (8 cases); these lesions were not found in any other type of acute viral hepatitis, and thus appeared to be diagnostic. Sinusoidal inflammatory infiltrates also were common in AHC, particularly in biopsy specimens obtained during the early phase of the disease. These inflammatory infiltrates did not appear to affect adjacent hepatocytes. Necrosis in AHC usually was spotty and accompanied by mixed inflammatory cells. In AHNC, necrosis was also spotty but, as an added feature, pigmented macrophages predominated in them. In AHA, necrosis was predominantly periportal, whereas in AHB, severe zone-3 necrosis predominated. Fatty changes were predominantly microvesicular; they were common in AHC but were also found in other groups. Collectively, the described histologic features allowed diagnosis of AHC in biopsy specimens with reasonable confidence. However, histologic findings failed to predict the prognosis in individual cases.

Acute Disease↗
PubMed1993

[An outbreak of gastroenteritis due to group C rotavirus in Tokyo].

In April 1991, an outbreak of acute gastroenteritis due to group C rotavirus occurred at an elementary school in Tokyo. Fifty-one (13%) of 393 students became ill. The main clinical symptoms were diarrhea (100%), abdominal pain (68%) and vomiting (56%). No enteropathogenic bacteria were found in the fecal specimens. However, the virus particles morphologically indistinguishable from conventional rotavirus were detected in 6 of 11 fecal specimens by electron microscopy. Immune electron microscopy showed that these virions aggregated with anti-group C rotavirus serum. The RNA pattern of the virus particles involved in this outbreak showed a pattern similar to that of typical group C rotavirus on polyacrylamide gel electrophoresis.

Child↗
PubMed1993

[On the outbreak of Shigellosis in Tokyo, 1992].

In 1992, the number of cases of shigellosis in Tokyo increased remarkably, and a total of 10 separate outbreaks were confirmed. Except for 1 series where the causative strains was Shigella flexneri 3a, the other 9 outbreaks were caused by Shigella sonnei. Of note, 7 outbreaks were familial with less than 5 patients. The remaining 3 outbreaks occurred in a restaurant, a school and the dormitory of an orphanage, in which the organism was detected in 6 to 14 patients. In 4 of the familial outbreaks occurring in distant areas during August, ark shell was presumed to be the vehicle by epidemiological investigations and laboratory examinations. Analysis of isolates such as the antibiotic resistance pattern, plasmid profile, or colicine type in Shigella sonnei was useful in clarifying the commonality of each case and identifying the vehicle or transmission.

Adult↗
PubMed1993

Serum anti-GQ1b IgG antibody is associated with ophthalmoplegia in Miller Fisher syndrome and Guillain-Barré syndrome: clinical and immunohistochemical studies.

To determine the significance of serum anti-GQ1b IgG antibody, we studied the disease spectrum associated with this antibody and GQ1b epitope in the human nervous system. We examined sera from 19 patients with typical Miller Fisher syndrome (MFS), five patients with acute postinfectious ophthalmoplegia without ataxia (atypical MFS), six patients with Guillain-Barré syndrome (GBS) with ophthalmoplegia (GBS-OP[+]), and 23 patients with GBS without ophthalmoplegia (GBS-OP[-]). We also examined sera from 84 patients with other neurologic or non-neurologic disorders and from 16 normal control subjects. Eighteen of the 19 patients with typical MFS, all the patients with atypical MFS, and five of the six patients with GBS-OP(+) had increased anti-GQ1b IgG activity in ELISA, but none of the patients in the other groups, including GBS-OP(-), had it. All the patients' sera that had anti-GQ1b IgG antibody showed anti-GT1a IgG activity. Results of absorption studies suggested that the same antibody reacted with GQ1b and GT1a. An anti-GQ1b mouse monoclonal antibody immunostained the paranodal regions of the extramedullary portion of the human oculomotor, trochlear, and abducens nerves. Biochemical analysis showed that the human oculomotor nerve contained a larger amount of GQ1b than did the ventral and dorsal roots of the spinal cord. We conclude that serum IgG antibody against GQ1b is very closely associated with acute postinfectious ophthalmoplegia in MFS and GBS.

Ataxia↗
PubMed1993

The prognosis of idiopathic portal hypertension in Japan.

To clarify the factors relating to the prognosis of patients with idiopathic portal hypertension (IPH), we followed 171 patients with IPH until the end of 1990, who were registered in the database among those with abnormal portal circulation as of 1985 in hospitals of Japan. During the follow-up period, twenty patients died; 6 from gastro-intestinal tract bleeding, 5 from hepatic insufficiency and 9 from other causes. Cox's proportional hazard model suggested that male patients (hazard ratio 4.85, 95% confidence interval 1.82-12.94), with a disease onset at less than 40 years of age (H.R.3.94, 95% C.I. 1.31-11.57), and/or with varices (H.R.2.86, 95% C.I. 1.05-7.77) generally had poorer prognoses.

Adult↗
PubMed1993

Immunohistochemical localization of epidermal growth factor in human main and accessory lacrimal glands.

Immunohistochemical localization of epidermal growth factor (EGF) in human main and accessory lacrimal glands has been investigated using monoclonal and polyclonal antibodies. Positive stain of EGF was localized in the cytoplasm of the acinar cells and the epithelial cells of the intra- and interlobular ducts of the main lacrimal glands, including both the palpebral and orbital lobes, and of the accessory lacrimal glands (gland of Krause, gland of Wolfring) as well. Meibomian glands showed weak immunoreactivity. Positive stain in the conjunctival epithelium including goblet cells was not observed. These results suggest that the mature form of EGF is produced in both the main and accessory human lacrimal glands and secreted into the tear fluid as a constant and crucial component.

Aged↗
PubMed1993

[New membrane filter (PORETEC) method for ocular diagnostic cytopathology].

We describe a new membrane filter (PORETEC) technique for processing cytopathologic fluid specimens. This procedure provides excellent cytologic preparations because there is no background staining and only a small amount of fluid specimen is necessary, as there is little cell loss. We compared the number of cells collected by the membrane filter technique with that collected by cytocentrifugation using conjunctival brush cytology specimens from 6 subjects. The number of cells obtained by the new method was significantly higher than that obtained by the cytocentrifugation technique. This method was very useful for ocular fluid specimens such as aqueous humor, vitreous specimens, and scrapings from the cornea and conjunctiva. We showed some examples of these specimens including immunocytochemical staining done by this method. We confirm that this is valuable for diagnostic cytopathologic study of various fluid specimens in ophthalmology.

Adult↗
PubMed1993

Clinical application of new membrane filter for cytopathological diagnosis in ophthalmology.

In order to evaluate the clinical usefulness of a new membrane filter method, PORETEC, for cytopathological diagnosis in ophthalmology, we performed a comparative study on conjunctival cell specimens using this method and a previously developed cytocentrifugation method. The subjects were 5 normal male volunteers (6 eyes) with an average age of 33 years. The conjunctival cells were obtained by brush cytology, and processed for both the new membrane filter and the cytocentrifugation methods. The total numbers of epithelial cells obtained by both methods were counted under a light microscope. The number of cells obtained by the cytocentrifugation method was 4933 +/- 2338 for each specimen, whereas that by the new membrane filter method was 12436 +/- 5281 (mean +/- SD). The difference was statistically significant (Wilcoxon signed-rank test, P < 0.05). The new membrane filter diagnostic method was also applied to specimens of aqueous humor from patients with uveitis or vitreous body from patients with proliferative diabetic retinopathy or endophthalmitis. The new method provided excellent cytopathological specimens which were also applicable for special staining and immunocytochemical study. We concluded that the new membrane filter is quite useful for cytopathological diagnosis of ocular fluid specimens.

Adult↗
PubMed1993

[A case of intrapulmonary lymph node with silicotic nodules in a patient with idiopathic interstitial pneumonia].

A 61-year-old man was admitted to our hospital on October 8, 1991 because of abnormal shadows on chest X-ray at annual checkup at his company. Chest X-ray and CT on admission showed diffuse reticular shadows in bilateral lower lung fields and a nodular opacity approximately 10 mm in diameter in the right lower lung. Since transbronchial lung biopsy was not diagnostic, an open lung biopsy was performed on October 28, 1991. The lung specimens showed diffuse pulmonary fibrosis compatible with usual interstitial pneumonia and an intrapulmonary lymph node containing silicotic nodules. Only 29 cases (including the present case) of intrapulmonary lymph nodes have been reported. Although the causes of intrapulmonary lymph nodes are not clear, smoking is considered to play an important role in the development of pulmonary lymphoid tissue. In our case, the intrapulmonary lymph node contained silicotic nodules. Only several case have been reported to have silicotic nodules in the lymph nodes. As suggested by Kradin, they may be induced by relatively low levels of exposure to dust. Our case also had pulmonary fibrosis (IIP), and is the first reported case of intrapulmonary lymph node associated with IIP. Although it is difficult to determine these two diseases occurred coincidently or not, it is possible that a low level of dust exposure may have contributed to both silicotic nodules in the lymph node and IIP.

Adult↗