Search PubMed⌕ Search

Biomedical subjects

S Yamada

Publications and source records attributed to S Yamada.

At least 685 records · Page 38Linked to original sources

Comparison of serum 7S fragment of type IV collagen and serum central triple-helix of type IV collagen for assessment of liver fibrosis in patients with chronic viral liver disease.

BACKGROUND/AIMS: A competitive radioimmunoassay for serum 7S fragment of type IV collagen (7S collagen) using a polyclonal antibody against 7S collagen and a sandwich enzyme immunoassay for serum central triple-helix of type IV collagen (IV collagen) using two monoclonal antibodies against the pepsin-solubilized type IV collagen may be used as diagnostic aids for liver fibrosis in clinical medicine. We compared the clinical usefulness for assessing liver fibrosis of serum 7S collagen and IV collagen tests in chronic viral liver diseases, and also examined the elution pattern of 7S collagen- and IV collagen-related antigens in serum by gel filtration analysis. METHODS: Serum 7S collagen and IV collagen levels were assayed in 151 patients with chronic viral liver disease and 30 healthy control subjects. RESULTS: Gel filtration on the Sephacryl S400HR column revealed that the 7S collagen antigenicity in serum was heterogeneous, whereas the IV collagen antigen in serum was uniform in size. Serum levels of 7S collagen and IV collagen showed increases closely correlated with the severity of liver disease. The abnormal percentage of 7S collagen in three patient groups was similar to that of IV collagen in the corresponding groups. Serum 7S collagen and IV collagen levels were strongly correlated with the histological degree of liver fibrosis; the correlation coefficients were r = +0.675 for 7S collagen and r = +0.665 for IV collagen. When we assessed the ability of each test to detect cirrhosis with a receiver operating curve, the serum 7S collagen test was a slightly better marker than the serum IV collagen test. For the detection of cirrhosis, serum 7S collagen was 83% sensitive and 88% specific at a cutoff value of 9 ng/ml, and serum IV collagen was 80% sensitive and 81% specific at a cutoff value of 160 ng/ml. CONCLUSIONS: These findings suggested that serum 7S collagen and IV collagen tests are similarly useful for assessing liver fibrosis in patients with chronic viral liver disease, although the former is slightly better for diagnosing cirrhosis than the latter.

Adult↗

Detection and identification of metabolites of microcystins formed in vivo in mouse and rat livers.

The hepatic metabolism of microcystins (MCs), potent cyclic peptide hepatotoxins produced by cyanobacteria, was studied by i.p. injection in mice and rats. An immunoaffinity purification method using an anti-MC-LR monoclonal antibody showed a remarkable effect on the removal of contaminants in the hepatic cytosol and enabled us to analyze MCs and their metabolites by HPLC and Frit-FAB LC/MS. At 3, 6, and 24 h post-injection of MC-RR, a small percent of the applied dose was detected in all of the mouse livers together with several metabolites. Among them, GSH and Cys conjugates of MC-RR were identified at 3 and 24 h, respectively, by comparison with the chemically prepared standards, indicating that the thiols of GSH and Cys nucleophilically bound to the Mdha moiety of MCs. Another metabolite was presumed to be formed by both epoxidation followed by hydrolysis and sulfate conjugation in the Adda moiety and GSH conjugation in the Mdha moiety. In rat livers, MC-LR showed almost the same behavior as that of MC-RR in mouse livers. These results suggest that the conjugation of GSH with MCs may play a role in the metabolic pathway leading to detoxification of MCs.

Animals↗

PET imaging of primary mediastinal tumours.

Mediastinal masses include a wide variety of tumours and remain an interesting diagnostic challenge for radiologist. We performed positron emission tomography (PET) studies of primary mediastinal tumours in order to predict the malignancy of these tumours preoperatively. Twenty-two patients with primary mediastinal tumours were studied with PET using 2-deoxy-2-[18F]fluoro-D-glucose (FDG). The histological findings of surgical pathology or biopsy, or mediastinoscopy were compared with those of computerised tomography (CT) and PET. PET images were evaluated semiquantitatively using the differential uptake ratio (DUR). Increased FDG uptake was observed in nine of ten patients with malignant tumours, including thymic carcinomas, lymphomas, invasive thymomas and a case of sarcoidosis. A moderate level of FDG uptake was found in a myeloma, non-invasive thymomas, and a schwannoma, whereas a low uptake was observed in a teratoma and various benign cysts. The mean FDG uptake of malignant tumours was significantly higher than that of benign tumours. Both thymic cancer and invasive thymoma showed a high FDG uptake. CT examination resulted in three false-negative and two false-positive cases when used in predicting tumour invasion, while PET was associated with a false-positive and a false-negative case. In conclusion, the use of FDG with PET is clinically helpful in evaluating the malignant nature of primary mediastinal tumours. Our results also suggest that a high FDG uptake reflects the invasiveness of malignant nature of thymic tumours.

Adolescent↗

Pit-1 gene expression in human pituitary adenomas using the reverse transcription polymerase chain reaction method.

OBJECTIVE: Previous studies of Pit-1 expression in human pituitary tumours have produced conflicting results. We have studied expression of Pit-1 mRNA in human pituitary adenomas, as well as in normal human and rat pituitaries, and results were compared with clinical, histological, and immunohistochemical features. In addition, expression of GH, PRL, and TSH-beta mRNA was also studied and compared with Pit-1 gene expression. MATERIAL AND METHODS: The adenomas consisted of 13 GH cell adenomas, 7 PRL cell adenomas, 3 TSH cell adenomas, 4 ACTH cell adenomas, and 10 clinically non-functioning adenomas. Expression of the Pit-1, its isoforms, and each hormone, was studied using the reverse transcription polymerase chain reaction. RESULTS: Pit-1 mRNA was expressed not only in normal human and rat pituitaries, but also in all GH, PRL and TSH cell adenomas. There was no correlation between Pit-1 transcripts and biological behaviour or histological findings in these three types of adenoma, suggesting that Pit-1 is generally required for the determination of cell phenotype but is insufficient for the regulation of hormonal activity and tumour growth in these pituitary adenomas. In addition, Pit-1 was also expressed in some ACTH cell (2/4) and non-functioning adenomas (7/10). Although there were no GH, PRL or TSH-beta transcripts in Pit-1 mRNA-negative ACTH cell and non-functioning adenomas, PRL mRNA was detected in all Pit-1 mRNA-positive ACTH cell adenomas and GH, PRL and/or TSH-beta mRNA were found in four of seven Pit-1 mRNA-positive non-functioning adenomas. In contrast, Pit-1 mRNA was expressed without any GH, PRL, or TSH-beta transcripts in only three non-functioning adenomas. These data suggest that expression of Pit-1 mRNA in these two types of adenomas can be mainly attributed to the presence of GH, PRL and/or TSH-beta mRNA expressing cells and that true Pit-1 transcripts found in non-functioning adenomas may be a rare event. Moreover, there were two cases which expressed Pit-1 alpha mRNA, but failed to show other Pit-1 isoform mRNA. There were, however, no clinical or histological differences between these two adenomas showing only Pit-1 alpha mRNA and the others expressing both Pit-1 alpha mRNA and other Pit-1 isoform mRNA. CONCLUSIONS: Pit-1 mRNA was expressed not only in GH, PRL and TSH cell adenomas but also in other types of adenoma. However, it is suggested that expression of Pit-1 mRNA in most ACTH cell and non-functioning adenomas can be attributed to GH, PRL and/or TSH-beta mRNA expressing cells. Further studies are necessary to elucidate the role of Pit-1 transcripts in the three non-functioning adenomas without GH, PRL and/or TSH-beta mRNA expression.

Adenoma↗

Retrospective analysis of long-term surgical results in acromegaly: preoperative and postoperative factors predicting outcome.

OBJECTIVE: Sixty-one of 83 patients with acromegaly treated between 1969 and 1993 were analysed retrospectively to clarify which early postoperative factors were significant predictors of a successful long-term outcome and which preoperative factors significantly influenced the early postoperative results. PATIENTS: Of the 61 patients, 30 were operated on before 1987 and 31 afterwards. A successful long-term surgical outcome was defined as a long-term mean basal GH level < 6 mU/l (comparable to < 3 micrograms/l), a normal IGF-I level, and normal GH dynamics. RESULTS: Overall, 59% of patients (37% before 1987 and 81% after) had an early postoperative mean basal GH level < 6 mU/l, and 56% (29% before 1987 and 77% after) met all three of the specified criteria for a successful long-term surgical outcome. Statistical analysis confirmed that GH dynamics and postoperative mean basal GH level < 6 mU/l were significant predictors of the long-term surgical outcome, whereas the postoperative IGF-I level alone was not. On the other hand, abnormal preoperative GH dynamics were normalized in all patients with a postoperative mean basal level < 6 mU/l. In addition, there were no patients showing an unsuccessful long-term outcome in those associated with both the early postoperative mean basal GH level < 6 mU/l and normalization of the IGF-I level. Therefore, measurement of the early postoperative mean basal GH level and the IGF-I level may be an economical and simple guide to predict the long-term surgical outcome. Moreover, multivariate analysis indicated that cavernous sinus invasion was an independent significant factor influencing the early postoperative outcome. CONCLUSIONS: Successful long-term surgical outcome may be predicted if early postoperative mean basal GH level is reduced to < 6 mU/l (< 3 micrograms/l) and IGF-I level becomes normal. This study also confirms that early diagnosis and treatment by an experienced endocrinologist and neurosurgeon can improve the operative results in patients with acromegaly.

Acromegaly↗

Relationship between serum and hepatic 7S fragments of type IV collagen in chronic liver disease.

We evaluated the mechanism of increased serum concentrations of the 7S fragment of the N-terminal domain of type IV collagen (7S collagen) in chronic liver disease. We measured the concentrations of hepatic-free and deposited 7S collagens after extraction with Tris-HCl buffer and bacterial collagenase, then compared them with the serum levels in 8 normal controls and 48 patients with chronic liver disease. The hepatic 7S collagen levels extracted with Tris-HCl buffer and collagenase accounted for 7% and 93%, respectively, of the total 7S collagen levels in normal controls. Both hepatic 7S collagen levels as well as serum levels increased in accordance with the progress of liver disease. Serum levels of 7S collagen showed a closer correlation with the hepatic 7S collagen levels extracted with Tris-HCl buffer (r = .822), compared with those extracted with collagenase (r = .382). On the other hand, the histological degrees of liver fibrosis were highly correlated with the hepatic collagenase-extracted 7S collagen levels (r = .822), compared with serum and the hepatic Tris-HCl buffer-extracted levels (r = .478 and r = .537, respectively). Although there was no difference in serum and hepatic 7S collagen levels between B and C viral patients, the serum and hepatic Tris-HCl buffer-extracted 7S collagen levels were higher in patients with alcoholic cirrhosis than patients with viral cirrhosis. However, the hepatic collagenase-extracted levels were similar in both groups. Gel filtration demonstrated that the serum and hepatic Tris-HCl buffer-extracted 7S collagens were mainly eluted in the macromolecular 7S collagen-reactive fraction in cirrhosis, whereas the hepatic collagenase-extracted 7S collagen was eluted in the authentic 7S collagen-reactive fraction. The results suggest that serum 7S collagen levels are not a particularly reliable measure of hepatic fibrosis but reflect the enhanced metabolism, especially synthesis of type IV collagen in the liver.

Adolescent↗

Normalization of middle latency auditory P1 potential following posterior ansa-pallidotomy in idiopathic Parkinson's disease.

The P1 potential (50 msec) of middle latency auditory evoked potential was evaluated in seven patients with advanced idiopathic Parkinson's disease before and after contemporaneous bilateral posterior ansa-pallidotomy. P1 potential was lacking in two patients preoperatively and was prolonged in the remainder of the patients when examined in a best medicated 'on' state. All patients showed varying degrees of dementia preoperatively on clinical examination. Remarkable improvement in their Unified Parkinson's Disease Rating Scale (UPDRS) scores during 'on' states from a mean of 45.85 to 14.28 post-operatively was achieved. Subsidence of akinetic symptoms, abolishment of dyskinesia, improvement in gait freezing, rigidity, and tremors represented main areas of improvement. P1 latencies and amplitudes reverted back to normal values in six patients including the two patients who lacked P1 wave preoperatively. One patient showed mild worsening of both Pa and P1 values post-operatively attributed to sleepiness during testing, a transient phenomenon commonly encountered following posterior ansa-pallidotomy. The post-operative P1 changes were statistically significant for both latencies and amplitudes at p = 0.078 and p = 0.073, respectively, for all seven patients using one tailed paired t-test. The change in UPDRS post-operatively best correlated with the post-operative difference in P1; specifically, UPDRS subscore II with P1 amplitude (r = -0.068, p = 0.09), and UPDRS subscore IV with Pa: P1 ratio (r = +0.77, p = 0.04). Earlier clinical and experimental work support the tegmental pedunculopontine nucleus (PPN) as the site of origin of P1 wave. In addition, its presence reflects the integrity of output cholinergic projection from PPN to both ascending reticular activating system ARAS and auditory pathway. We believe this is the first report of restoring the integrity of P1 wave following posterior ansa-pallidotomy in patients with advanced idiopathic Parkinson's disease. Disinhibition of the PPN by posterior ansa-pallidotomy can explain improvements in motor symptoms in view of reemergence and normalization of P1 wave form.

Evoked Potentials, Auditory↗

An aminopeptidase inhibitor, bestatin, enhances progesterone and oestradiol secretion by porcine granulosa cells stimulated with follicle stimulating hormone in vitro.

We examined the presence of cell surface aminopeptidase on cultured porcine granulosa cells by employing the aminopeptidase assay using alanine-p-nitroanilide and histochemical staining using L-leucyl-beta-naphthylamide. Porcine granulosa cells obtained from follicles 4-5 mm in diameter were cultured for 7 days. The aminopeptidase assay showed that the porcine granulosa cell culture had aminopeptidase activity and that this activity was inhibited in a dose-dependent manner by bestatin which binds to cell surfaces and inhibits cell surface aminopeptidases. Histochemical staining also indicated that cultured granulosa cells had aminopeptidase activity. Porcine granulosa cells were cultured in the presence or absence of porcine follicle stimulating hormone (FSH, 3.125 nmol/l) and/or bestatin (0.4, 4.0 and 40.0 micrograms/ml) for 7 days, and the production of progesterone and oestradiol was measured. In the presence of porcine FSH, the production of progesterone and oestradiol by granulosa cells was increased significantly by approximately 5- and 2-fold respectively. These increases were enhanced further by bestatin (40.0 micrograms/ml). In the absence of porcine FSH, progesterone production was enhanced by bestatin (40.0 micrograms/ml), whereas no significant effect of bestatin on oestradiol secretion was observed. These findings indicate that the inhibition of membrane-bound aminopeptidase(s) on the cell surfaces affects the steroidogenesis of granulosa cells, and that these aminopeptidase(s) are important regulators of granulosa cell differentiation.

Aminopeptidases↗

Electron microscopic observations of aberrant capsids of pseudorabies virus.

Interactions between four strains of pseudorabies virus (PrV) and seven kinds of cell lines were examined. Three kinds of cells (SKL, CPK and PK-15) were especially infected with PrV at an MOI of about 10 PFC/cell. At sequential intervals after infection, cells of these types were collected for electron microscopic observations and the infectious doses of culture fluids were assayed. Developmental features of PrV were found to be very similar to those of herpes simplex virus (HSV), with the slight difference that PrV developed a little earlier and more vigorously than did HSV. At the late stage of infection, aberrant capsids of PrV were observed frequently in the nucleus of SKL but rarely in the nuclei of CPK and PK-15. The titer of infectious virus produced by SKL was much larger than that produced by CPK and PK-15. Immuno-electron microscopic examination using a monoclonal antibody against the major capsid protein of PrV clearly demonstrated that the complete and aberrant capsids have a common epitope. The mechanism of the formation of aberrant capsids is discussed.

Animals↗

Activation of 20S proteasomes from spinach leaves by fatty acids.

In order to clarify the mechanism of activation plant 20S proteasomes by fatty acids, we examined the effects of oleic, linoleic and linolenic acids on the three of peptidase activities of purified 20S proteasomes from spinach leaves and compared them with the effects of SDS, a previously characterized activator of 20S proteasomes. The three fatty acids all activated the hydrolysis of succinyl-Leu-Leu-Val-Tyr-4-methylcoumaryl-7-amide (Suc-LLVY-MCA) and benzyloxycarbonyl-Leu-Leu-Glu-2-naphthyl-amide (Cbz-LLE-2NA) at low concentrations (one-third to one-sixth of that required for activation by SDS). The range of concentrations of linolenic acid for the activation of Suc-LLVY-MCA hydrolysis was very narrow. All the fatty acids inhibited the hydrolysis of tert-butoxycarbonyl-Leu-Arg -Arg-4-methylcoumaryl-7-amide (Boc-LRR-MCA) at extremely low concentrations (one-fifth to one-fifteenth of that required for the activation of the hydrolysis of Suc-LLVY-MCA and Cbz-LLE-2NA). In the case of hydrolysis of Suc-LLVY-MCA, SDS and the three fatty acids increased the Vmax value and decreased the apparent Km value to similar relative extents. In the case of hydrolysis of Boc-LLE-MCA, SDS and the three fatty acids also decreased the Km and increased the Vmax. However, SDS markedly increased Vmax. the curves representing the SDS-dependent activation were shifted to a lower range by the addition of linoleic acid, but the maximum activity at the optimum concentration of SDS was essentially unchanged. These results suggest that the activation by SDS and that by the fatty acids has an additive effect. The results imply that fatty acids, such as linolenic acid, might act as physiological regulators in plant cells.

Amino Acid Sequence↗

Split posterior tibial tendon transfer for varus deformity of hindfoot.

Sixteen patients (23 feet) who underwent split posterior tibial tendon transfers were evaluated. The patients were seen on a followup basis for a minimum of 1 year postoperatively. The causes were spastic cerebral palsy in 13 feet, spastic-athetoid cerebral palsy in 3 feet, hydrocephalus in 3 feet, and other diseases in 4 feet. The indication for surgery was varus deformity during the stance phase of gait and increased varus deformity during the swing phase of gait because of spasticity of the posterior tibial muscle. Heel cord lengthening was done on 17 feet. Preoperative and postoperative gaits were evaluated while the patients were walking. Axial radiographs of the calcaneus and the tibia were taken of all patients while they were weightbearing. There were 15 excellent, 6 good, and 2 poor results. The poor ratings were assigned to patients who had recurrence of varus deformity; there were no cases of overcorrection. Split posterior tibial tendon transfer was effective for treating spastic varus deformity of the hind part of the foot. This treatment also could be considered for a patient with spastic-athetoid cerebral palsy, if the deformity was determined to be caused by overactivity of the tibialis posterior muscle.

Adolescent↗

Bypass coaptation procedures for cervical nerve root avulsion.

In the past, patients with cervical spinal nerve root avulsions were resigned to accept a natural crippling from upper extremity neurological deficits. Recently, bypass coaptation procedures have resulted in functional return of denervated muscles after such avulsions, much to the appreciation of patients. Presented are 12 patients with avulsion of cervical spinal nerve roots that form either the brachial plexus upper trunk (n = 7), lower trunk (n = 1), or all three trunks (n = 4). The patients underwent the new bypass coaptation procedures with complete or partial return of motor and sensory function, which otherwise would be totally nonfunctional. The most dramatic results were noted in those patients who underwent operations within 6 weeks of injury. The results of these procedures offer patients a valid therapeutic modality for an enhanced quality of life after cervical nerve root avulsion.

Adult↗

Detection of Fc receptor genes from Staphylococcus aureus and streptococci by polymerase chain reaction.

A method based upon the polymerase chain reaction (PCR) for detecting genes encoding the Fc receptors of Staphylococcus aureus and streptococci is described. Primers were designed from the nucleotide sequences of the five Fc receptor genes encoding protein A, protein G, protein H, FcRA and protein V. Amplification products corresponding in size to the protein A and protein G genes were detected in S. aureus strain Cowan 1 and Streptococcus pyogenes strain G148, respectively, as expected. Str. pyogenes strain AR1 was shown to possess the type H receptor gene. Two clinical isolates of Str. pyogenes, strains IP-28 and ES-21L, were shown to possess genes for Fc receptor types FcRA and protein G, respectively. The identification of all these products was confirmed by restriction endonuclease analysis. Amplification of protein H genes from two other clinical isolates of streptococci, MS-4 and MS-38, yielded a product larger than expected and with a different restriction fragment pattern to strain AR1, indicating a new type of Fc receptor gene. This PCR method provides a DNA-based method for the determination of Fc receptor type in S. aureus and streptococci.

Bacterial Proteins↗

Distribution of transforming growth factor-beta and its receptors in gastric carcinoma tissue.

The distribution of the three mammalian isoforms of transforming growth factor (TGF)-beta (TGF-beta 1, -beta 2, and -beta 3) as well as their signaling receptors, TGF-beta type I and type II receptors (T beta R-I and T beta R-II, respectively), in gastric carcinoma tissue was examined by immunohistochemistry using specific antibodies. Tissue specimens were obtained from 25 cases of gastric carcinoma, which were classified into two groups according to Lauren's classification, i.e. 15 cases of diffuse carcinoma and 10 cases of intestinal carcinoma. In normal gastric mucosa apart from carcinoma nests, all of TGF-beta 1, -beta 2, -beta 3, T beta R-I and T beta R-II were clearly demonstrated in fundic glands. In sharp contrast, none of them was detectable in surface mucous cells. In carcinoma cells, strong staining for TGF-beta 1, -beta 2 and -beta 3 was obtained only in diffuse-type carcinoma. In particular, carcinoma cells scattered as single cells or small nests had a tendency to show strong staining for TGF-betas. The receptors tended to be distributed concomitantly with the ligands, and diffuse-type carcinoma showed stronger receptor staining than intestinal-type carcinoma. In cancer stroma, TGF-betas and receptors were detected in both diffuse and intestinal types, but the area with positive staining was wider and more dispersed in diffuse-type carcinoma than in intestinal carcinoma. These results suggest that TGF-beta may contribute in part to the variety of histogenesis and mode of progression of gastric carcinoma.

Adenocarcinoma↗

Detection of low-level expression of P-glycoprotein in ACHN renal adenocarcinoma cells.

A highly sensitive reverse transcriptase-polymerase chain reaction (RT-PCR) assay and a flow cytometric assay were used to examine ACHN cells for the expression of P-glycoprotein. The expression of P-glycoprotein was detected at the RNA and protein levels in ACHN cells by RT-PCR and flow cytometry, respectively. However, it was below the limit of detection by immunoblotting. The intracellular accumulation of adriamycin in ACHN cells was enhanced by verapamil, cyclosporin A and medroxyprogesterone acetate. Therefore, this study has demonstrated that low-level expression of P-glycoprotein detectable only by RT-PCR and flow cytometry plays a significant role in reducing the intracellular concentration of antitumor agents and thus contributes to the multidrug-resistant phenotype of ACHN cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

[Characteristics of Salmonella strains isolated from sporadic diarrheal cases during 1992-1994 in the Philippines].

A total of 263 Salmonella strains isolated in Metro Manila, the Philippines from 1992 to 1994, were examined for their serovar-distribution and drug-resistance. Salmonella serovar Typhi (S. Typhi) and S. Enteritidis phage type was also tested. The serological typing results showed that the strains were classified into 10 O-groups and 32 serovars. S. Weltevreden, S. Enteritidis, S. Typhi, S. Typhimurium, and S. Derby were predominant in the serovars identified. The drug-resistance test using nine drugs (CP, TC, SM, KM, ABPC, ST, NA, FOM, and NFLX) showed that 95 strains (36.1%) were resistant to any of the seven drugs except FOM and NFLX. The serovars of a high resistant rate were S. Ruiru (100%), S. Typhimurium (87.0%), S. Senftenberg (80.0%), S. Derby (66.7%), and S. Agona (50.0%). Drug-resistance patterns of the resistant strains varied to 21 types, and 80 of them were multidrug-resistant. Phage types of 37 S. Typhi strains were B1 (27 strains), E2 (6 strains), and others (4 strains). Phage types of 38 S. Enteritidis strains were 4 (32 strains), 7 (3 strains), and others (3 strains).

Ampicillin Resistance↗

[Serovar-distribution and drug-resistance of Salmonella strains isolated from domestic and imported cases in 1990-1994 in Tokyo].

A total of 3,647 non-typhoidal Salmonella strains consisting of 2,655 domestic strains and 992 imported strains isolated in Tokyo from 1990 to 1994, were examined for their serovar-distribution and their drug-resistance. The serological typing results showed that the domestic strains were classified into 15 O-groups and 96 serovars, and the imported strains were classified into 13 O-groups and 73 serovars. Among the serovars identified, Salmonella serovar Enteritidis (S. Enteritidis), S. Thompson, S. Hadar, S. Litchfield, and S. Tennessee were predominant in the domestic strains, whereas S. Hadar, S. Enteritidis, S. Anatum, S. Derby, and S. Blockley were predominant in the imported strains. The drug-resistance test using 9 drugs (CP, TC, SM, KM, ABPC, ST, NA, FOM, and NFLX) showed that 30.5% of the domestic strains and 40.5% of the imported strains were resistant to any of the drugs examined. The serovars of a high resistant rate during this period were S. Hadar (96.2%), S. Blockley (88.7%), S. Enteritidis (63.4%), S. Virchow (54.3%), and S. Typhimurium (51.3%) in the domestic strains and S. Krefeld (100%), S. Hadar (98.9%), S. Blockley (98.2%), S. Emek (83.3%), S. Kentucky (76.5%), S. Panama (69.2%), S. Derby (63.8%), S. Typhimurium (57.1%), S. Rissen (55.6%), and S. Agona (53.7%) in the imported strains. Drug-resistance patterns of the resistant isolates varied to 62 types. Prevalent patterns recognized were SM, TC.SM, TC.SM.KM, TC, TC.SM.KM.ABPC and CP.TC.SM.KM in the domestic strains and TC.SM, TC, CP.TC.SM.ST, TC.SM.KM, and CP.TC.SM.KM in the imported strains.

Diarrhea↗

[Detection of the trh gene in Vibrio parahaemolyticus isolated from overseas travellers' diarrhea and their biochemical characteristics].

A total of 478 Vibrio parahaemolyticus strains isolated from overseas travellers' diarrhea during the last 7 years of 1989 to 1995 were examined for the production of Kanagawa hemolysin by reversed passive latex agglutination (RPLA) test. Three hundred-seventy (77.4%) out of 478 strains were positive for Kanagawa hemolysin, whereas 108 strains were weakly positive or negative. For those Kanagawa hemolysin-weakly positive or negative strains, the tdh and trh genes associated with the production of TDH (thermostable direct hemolysin) and TRH (TDH-related hemolysin), respectively, were studied by the polymerase chain reaction method. The trh gene was detected in 98 (90.7%) out of 108 strains. In 35 strains belonging to 13 serotypes such as O3: K6, O1:K33, O3:K59, the trh gene alone was detected. On the other hand, both trh and tdh genes were detected in 63 strains of 17 serotypes including O1:K69, O3:K72, O6:K46. Among the strains of 4 serotypes including O1:K56, O1:KUT, O3:KUT and O5:KUT, two types of the trh positive alone and the trh and tdh positive were observed. Of interest, all of the 98 trh-positive strains were positive for the urease hydrolysis, whereas all Kanagawa hemolysin-positive strains were not. Furthermore, the strains of serotype O6:K18 (4 strains) were positive for the fermentation of dulcitol, and the strains of serotype O1:K1 (5 strains) were indole negative. These characteristics of the strains were completely different from those of typical V. parahaemolyticus strains.

Diarrhea↗