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Biomedical subjects

Ryo Hondo

Publications and source records attributed to Ryo Hondo.

16 recordsLinked to original sources
PubMed2006

Inhibitory mechanism of monensin on high K+-induced contraction in guniea-pig urinary bladder.

In this study, we examined the inhibitory mechanism of monensin on high K+-induced contraction in guinea-pig urinary bladder. The relaxant effect of monensin (0.001 - 10 microM) was more potent than those of NaCN (100 microM - 1 mM) and forskolin (3 - 10 microM). Monensin (0.1 microM), NaCN (300 microM), or forskolin (10 microM) inhibited high K+-induced contraction without decreasing [Ca2+]i level. Monensin and NaCN remarkably decreased creatine phosphate and ATP contents. Monensin and NaCN inhibited high K+-induced increases in flavoprotein fluorescence, which is involved in mitochondrial respiration. Forskolin increased cAMP content but monensin did not. Monensin increased Na+ content at 10 microM but not at 0.1 microM that induced maximum relaxation. In the alpha-toxin-permeabilized muscle, forskolin significantly inhibited the Ca2+-induced contraction, but monensin did not affect it. These results suggest that the relaxation mechanism of monensin in smooth muscle of urinary bladder may be an inhibition of oxidative metabolism.

Adenosine Triphosphate↗
PubMed2006

Invasion assay of Listeria monocytogenes using Vero and Caco-2 cells.

The invasion ability of Listeria monocytogenes into cultured cells has been used to evaluate its pathogenicity. In this study, invasive ability was investigated using Vero and Caco-2 cell lines. The form of invasion showed no morphological differences between both cell lines inoculated with L. monocytogenes L89-H2 or L96-23C1 strains when double fluorescence stained with rhodamine and FITC or with Giemsa staining. Recovery count and recovery rate of L. monocytogenes from Vero cells was related to the number of inoculated bacteria (2 x 10(5) to 2 x 10(7)/ml) in a bell-shape pattern, though the relationship was unclear in Caco-2 cells. Recovery rate of L. monocytogenes was higher in Vero cells than Caco-2 cells at a multiplicity of infection (MOI) 10, though the rates in both cells showed different stable stages over a considerably wide range of MOI. The recovery rate of all five L. monocytogenes strains from listeriosis patients was 15% at MOI 10 from infected Vero cells, while meat-derived strains showed variable rates regardless of the serovar. These results suggest that the Vero cell line is suitable for an invasion assay and that a recovery rate of 15% may be the critical limit for the expression of pathogenicity in the host.

Animals↗
PubMed2005

Discrimination of Listeria monocytogenes contaminated commercial Japanese meats.

Discrimination was attempted on 14 Listeria monocytogenes strains isolated from commercially available Japanese pork and chicken. Examination of the isolates was performed by restriction fragment length polymorphism (RFLP) analysis of the chromosomal DNA and amplified products and comparison of the nucleotide sequences of the amplified products. A polymorphism region containing the repeated sequences in the iap gene was amplified by the polymerase chain reaction (PCR). The genetic analyses could discriminate the 14 isolates in combination with traditional serotyping, and some strains isolated from different meats were confirmed to have a genetically close relationship. Genetic analyses used in the present study would be useful for the elucidation of the pathogen tracks from contaminated sources to humans and of the ecological niche in the food environment.

Animals↗
PubMed2005

Rapid and sensitive detection of mumps virus RNA directly from clinical samples by real-time PCR.

A rapid, sensitive, and specific assay to detect mumps virus RNA directly from clinical specimens using a real-time PCR assay was developed. The assay was capable of detecting five copies of standard plasmid containing cDNA from the mumps virus F gene. No cross-reactions were observed with other members of Paramyxoviridae, or with viruses or bacteria known to be meningitis pathogens. Seventy-three clinical samples consisting of throat swabs collected from patients with parotitis, and cerebrospinal fluid (CSF) collected from patients with aseptic meningitis, were examined with a real-time PCR assay developed by the authors, reverse-transcription nested-PCR (RT-n-PCR), and virus isolation using cell culture. Like the RT-n-PCR assay, the real-time PCR assay could detect mumps virus RNA in approximately 70% of both throat swabs and CSF samples, while, by tissue culture, mumps virus was isolated from only approximately 20% of CSF and 50% of throat swab samples. In addition, the real-time PCR assay could be developed easily into a quantitative assay for clinical specimens containing more than 1,800 copies of mumps virus RNA/ml by using serial dilutions of the standard plasmid. The results suggest that the real-time PCR assay is useful for identification of mumps virus infections, not only in typical cases, but also in suspected cases, which show only symptoms of meningitis or encephalitis.

Humans↗
PubMed2005

Herpes simplex virus type 2 recurrent meningitis (Mollaret's meningitis): a consideration for the recurrent pathogenesis.

We report a 44-year-old Japanese woman with herpes simplex virus (HSV) type 2 recurrent meningitis (Mollaret's meningitis). The diagnosis was confirmed by nested polymerase chain reaction in her cerebrospinal fluid, but the patient's conventional HSV antibodies by complement fixation, neutralizing test or enzyme immunoassay showed low titres with low lymphoproliferative response. Several similar cases are discussed. Although the reason for the recurrent pathogenesis is uncertain, our report suggests that the low immune response including immune evasion may be involved in the pathogenesis of HSV type 2 recurrent meningitis. For this patient, long-term suppressive and patient-initiated therapies were conducted to prevent the recurrence of meningitis.

Acyclovir↗
PubMed2005

Thallium contamination in wild ducks in Japan.

Although thallium (Tl) is toxic to both humans and animals, there is little information on contamination in wildlife. In this study, Tl contents in wild ducks in Japan were determined. Contents of Tl in kidney and liver ranged from 0.42 to 119.61 and 0.10 to 33.94 microg/g dry weight, respectively. Significant correlations between Tl contents in kidney and liver were observed for all dabbling ducks except mallard (Anas platyrhynchos); similar correlations were not observed in diving ducks. Variation in Tl content was observed between sampling locations with the highest mean Tl content in the Eurasian wigeon (Anas penelope) collected in Ibaraki Prefecture.

Animals↗
PubMed2005

Comparison of genomic structures in the serovar 1/2a Listeria monocytogenes isolated from meats and listeriosis patients in Japan.

Foodborne disease by Listeria monocytogenes, serovar 1/2a has recently been reported in many countries. Although contamination by this bacteria is also known to be gradually spreading among the marketed foods of Japan, there is little information on relation between listeriosis and food contamination. In the present study, the characteristics of the genomic structures of serovar 1/2a were compared among the isolates from marketed meats and listeriosis patients. Several isolates from meats purchased at the same shop on different days had the same genomic structure, and prolonged contamination was suggested by the conditions in the shop. Genomic structures of one strain isolated from meat were identical to those of two isolates from a patient. Another isolate was obtained from meats purchased at two different shops, and this isolate was also identical to that of the isolates from another patient. These findings suggest that the isolates from meat may have caused the listeriosis in the patients, and that the strains may have somehow traveled between the shops.

Animals↗
PubMed2005

Analysis of the molecular evolution of Listeria monocytogenes isolated from Japanese meats and environment.

Food contaminated by Listeria monocytogenes is a problem on a worldwide level because it is a serious food-borne pathogen. Although 3 evolutionary divisions have been reported for L. monocytogenes, the evolution of Japanese isolates has not yet been clarified. Thus, in order to determine the lineage of these Japanese isolates, we classified and conducted phylogenetic analysis of 407 bp (position 1116-1522) of the iap gene derived from 88 isolates from Japanese listeriosis patients, foods and environment. The isolates were classified into 18 types commonly accompanied by serotypes, and the types were divided into 3 lineages. Our results suggest that these Japanese isolates belong to the 3 lineages of L. monocytogenes isolated in other countries.

Animals↗
PubMed2005

[Infectious disease of simian herpes B virus].

The epidemiology and the method of diagnosis were elucidated for simian herpes B virus (SHBV) infection. It is important that usefulness was demonstrated for the methods of DNA diagnosis having high sensitivity and specificity for SHBV and HSV-1, 2 types, and of detectable serological diagnosis for each specific antibody. The methods allowed the final diagnosis of the human infection due to the reactivation of latent SHBV and the HSV infection from human to monkey. These results would be able to become important and fundamental knowledge for the sero-epidemiological analysis of the infectious stile.

Animals↗
PubMed2004

Specific detection and identification of herpes B virus by a PCR-microplate hybridization assay.

Herpes B virus DNA was specifically amplified by PCR, targeting the regions that did not cross-react with herpes simplex virus (HSV). The amplified products, which were shown to be highly genetic polymorphisms among herpes B virus isolates, were identified by microplate hybridization with probes generated by PCR. The products immobilized in microplate wells were hybridized with the biotin-labeled probes derived from the SMHV strain of herpes B virus. The amplified products derived from the SMHV and E2490 strains of herpes B virus were identified by microplate hybridization. PCR products amplified from the trigeminal ganglia of seropositive cynomolgus macaques were identified as herpes B virus DNA. The utility of the PCR-microplate hybridization assay for genetic detection and identification of the polymorphic region of herpes B virus was determined.

Animals↗
PubMed2002

Cadmium contamination in wild birds as an indicator of environmental pollution.

Cadmium (Cd) is an environmental pollutant that has serious toxicity in humans and animals and causes Itai-Itai disease. However, there is little available information on its contamination in wildlife as an indicator of environmental pollution. The Cd contents in the kidney and liver of 85 wild birds from 9 different prefectures in Japan were investigated. The ranges of the Cd contents in the kidney and liver in all birds were ND-174.4 and ND-21.2 microg g(-1) dry wt., respectively. The mean Cd contents were higher in the oil-contaminated birds than those in the non-contaminated ones. Furthermore, a strong correlation was obtained only between the Cd contents in the kidney and those in the liver of the oil-contaminated seabirds and not in the other non-contaminated ones. These results suggest that wild birds reflect the level of environmental contamination which should be monitored.

Animals↗
PubMed2002

The distribution of molybdenum in the tissues of wild ducks.

The Mo contents and the relations between Mo and Cu or Cr contents were investigated in the organs of Japanese wild ducks (spotbill duck, pintail, wigeon, scaup and tufted duck). The highest Mo content in kidney and liver of the dabbling ducks were more than 30 microg g(-1) dry weight (microg g(-1) d. wt.), though that of diving ducks were less than 11 microg g(-1) d. wt. The contents were lower in the ducks migrating within Japan, Eurasia and North America than those in the birds migrating between Japan and Eurasia. The contents of liver in all species were more than 50 and less than 5 microg g(-1) d. wt. for Cu and Cr, respectively. Significant correlations were found between Mo and both elements in pintail and scaup, and Mo and Cr in tufted duck. These results suggest that the contamination of wild ducks reflects the reproductive area, and not the collected area. Mo contents closely correlated with the Cu and/or Cr contaminations.

Animals↗
PubMed2002

Detection of varicella zoster virus DNA in tear fluid and saliva of patients with Ramsay Hunt syndrome.

OBJECTIVE: To clarify the dynamics of the reactivation of the varicella zoster virus in Ramsay Hunt syndrome. SUBJECTS AND METHODS: Varicella zoster virus DNA in the tear fluid, submandibular gland saliva, and parotid gland saliva of 15 patients with Ramsay Hunt syndrome was studied. The presence of varicella zoster virus DNA was detected quantitatively by the use of polymerase chain reaction and a microplate hybridization method. RESULTS: Of 102 specimens of the tear fluid and saliva collected from 15 patients, varicella zoster virus DNA was detected in 40 specimens (39%) from 12 patients (80%). The detection rate was 72% in the submandibular saliva, 57% in the parotid saliva, and 27% in the tear fluid. Varicella zoster virus DNA was detected not only in specimens from the affected side but also in specimens from the unaffected side at the same rate of detection, and at nearly the same number of DNA copies. Regarding the parotid saliva, varicella zoster virus DNA was detected in samples collected at an early stage of the disease. In the tear fluid and submandibular saliva, however, the detection rate was high in samples collected 2 weeks after the onset of disease or later. CONCLUSIONS: Secretion of varicella zoster virus DNA into the tear fluid and saliva was confirmed in the patient with Ramsay Hunt syndrome. The increase and decrease in the detection rate and the number of varicella zoster virus DNA copies detected in samples collected at different times was considered to substantiate varicella zoster virus reactivation in Ramsay Hunt syndrome. Varicella zoster virus reactivation was thought to occur in the unaffected side at the same level as in the affected side, and some of the secreted varicella zoster virus DNA was suspected to be derived from the ganglion trigeminale.

Adult↗
PubMed2002

Secretion and dynamics of herpes simplex virus in tears and saliva of patients with Bell's palsy.

OBJECTIVE: For clarification of the direct relationship between the reactivation of herpes simplex virus and the development of Bell's Palsy, a detection of the virus genome by deoxyribonucleic acid diagnostics and a quantitative analysis of its time-course change are both needed. The authors detected the HSV genome in specimens from patients with Bell's Palsy, quantified its number of copies, and examined time-course changes. SUBJECTS AND METHODS: The subjects were 16 patients with Bell's Palsy. The tear fluid and saliva from the submandibular gland and the parotid gland were separately collected from the affected and unaffected sides twice or more. A total of 244 specimens were subjected to extraction of deoxyribonucleic acid, polymerase chain reaction, and microplate hybridization. RESULTS: Herpes simplex virus-1 deoxyribonucleic acid was detected in 38 specimens (11.8%) from 5 patients (31%). The high detection (28.5%) was obtained within 2 weeks after onset. Detection at 3 weeks and later (2.8%) was significantly lower ( < 0.05). In three cases, deoxyribonucleic acid was also found on the unaffected side in the initial phase of the disease, but detection on that side (18.9%) was significantly lower than on the affected side (83.8%) ( < 0.01). The number of copies of the herpes simplex virus-1 genome was large on the affected side and early after the onset of the disease. CONCLUSIONS: The reactivation of herpes simplex virus-1 on the affected side is involved as a pathogenic factor of Bell's Palsy. A reactivation of herpes simplex virus-1 may be generated even on the unaffected side in the early phase of the disease. Herpes simplex virus deoxyribonucleic acid was not detected in any of the examined specimens collected from the remaining 11 cases. The need for constant study to clarify other causative factors of Bell's Palsy remains.

Adolescent↗
PubMed2002

Simultaneous analysis for multiple heavy metals in contaminated biological samples.

In the present study, the conditions of analysis by inductively coupled plasma-atomic emission spectrometry (ICP-AES) were investigated. Twenty-six elements (Mg: 25 ppm; Sc: 10 ppm; Ti: 50 ppm; others: 100 ppm) were used as the elements interfering with selected 24 wavelengths. Consequently, the background values in 19 elements were subjected to some influences. However, all of these effects disappeared at low concentrations--less than 1 ppm of interfering elements. Next, the values from the ordinary calibration method were compared with those from the standard addition method using several biological samples. There was a discrepancy in the results obtained from both methods because of the sample, and three patterns were observed. However, no discrepancy was observed in the values for the standard reference materials using both methods. There was no significant difference between the certified values of the standard reference materials and the obtained ones by ICP. Therefore, the analytical wavelengths and the methods in the present study were suggested to be useful for ICP-AES analysis for environmental and/or biological samples.

Calibration↗