Biomedical subjects

M Seki

Publications and source records attributed to M Seki.

At least 19 recordsLinked to original sources

PubMed2006

Ovarian follicular and corpus luteum changes, progesterone concentrations, estrus and ovulation following estradiol benzoate/progesterone based treatment protocol in cross-bred cows.

The objectives of the present study were to investigate the effects of the stage of the estrous cycle at the start of an estradiol benzoate (EB) and progesterone (P) based treatment protocol on new follicular wave emergence, subsequent estrus and ovulation. The experiment was conducted using a crossover design with each cow (five cross-bred cows) being assigned to one of three groups at 3-month intervals within a 1-year period. Estrous cycle stage in individual cows was initially synchronized with prostaglandin F(2)alpha. After detection of estrus, each cow was injected intramuscularly (i.m.) with 2 mg EB and 200 mg P (EB/P) on day 5, 12 or 17 of the estrous cycle (estrus=day 0), followed by 1 mg EB i.m. 12 days after the EB/P treatment. Ovarian ultrasonographic examinations showed that the emergence of a new follicular wave occurred after EB/P treatment in all groups and the mean interval from EB/P treatment to wave emergence did not differ among the groups (3.2-3.8 days). All cows in each group exhibited behavioral estrus and ovulated the newly formed dominant follicle. However, cows in the day-17 group exhibited estrus 1-3 days before the second EB injection. The concentrations of progesterone showed faster reduction, during the treatment period, in the day-12 and -17 groups compared to the day-5 group. These results indicate that the EB/P treatment induces an emergence of a new follicular wave, irrespective of the estrous cycle stage at the start of treatment, but the effect of EB/P protocol on estrous/ovulation synchronization is influenced by the stage of the estrous cycle.

Animals↗

PubMed2006

The female-killing chromosome of the silkworm, Bombyx mori, was generated by translocation between the Z and W chromosomes.

Bombyx mori is a female-heterogametic organism (female, ZW; male, ZZ) that appears to have a putative feminizing gene (Fem) on the W chromosome. The paternally transmitted mutant W chromosome, Df(p ( Sa ) + ( p )W + ( od ))Fem, derived from the translocation-carrying W chromosome (p ( Sa ) + ( p )W + ( od )), is inert as femaleness determinant. Moreover, this Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome has been thought to have a female-killing factor because no female larvae having the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome are produced. Initially, to investigate whether the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome contains any region of the W chromosome or not, we analyzed the presence or absence of 12 W-specific RAPD markers. The Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome contained 3 of 12 W-specific RAPD markers. These results strongly indicate that the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome contains the region of the W chromosome. Moreover, by using phenotypic and molecular markers, we confirmed that the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome is connected with a partially deleted Z chromosome and that this fused chromosome behaves as a Z chromosome during male meiosis. Furthermore, we demonstrated that the ZZW-type triploid female having the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome is viable. Therefore, we concluded that the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome does not have a female-killing factor but that partial deletion of the Z chromosome causes the death of the ZW-type diploid female having the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome. Additionally, our results of detailed genetic analyses strongly indicate that the female-killing chromosome composed of the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome and deleted Z chromosome was generated by translocation between the Z chromosome and the translocation-carrying W chromosome, p ( Sa ) + ( p )W + ( od ).

Animals↗

PubMed2006

Innate immune peptide LL-37 displays distinct expression pattern from beta-defensins in inflamed gingival tissue.

Anti-microbial peptides produced from mucosal epithelium appear to play pivotal roles in the host innate immune defence system in the oral cavity. In particular, human beta-defensins (hBDs) and the cathelicidin-type anti-microbial peptide, LL-37, were reported to kill periodontal disease-associated bacteria. In contrast to well-studied hBDs, little is known about the expression profiles of LL-37 in gingival tissue. In this study, the anti-microbial peptides expressed in gingival tissue were analysed using immunohistochemistry and enxyme-linked immunosorbent assay (ELISA). Immunohistochemistry revealed that neutrophils expressed only LL-37, but not hBD-2 or hBD-3, and that such expression was prominent in the inflammatory lesions when compared to healthy gingivae which showed very few or no LL-37 expressing neutrophils. Gingival epithelial cells (GEC), however, expressed all three examined anti-microbial peptides, irrespective of the presence or absence of inflammation. Moreover, as determined by ELISA, the concentration of LL-37 in the gingival tissue homogenates determined was correlated positively with the depth of the gingival crevice. Stimulation with periodontal bacteria in vitro induced both hBD-2 and LL-37 expressions by GEC, whereas peripheral blood neutrophils produced only LL-37 production, but not hBD-2, in response to the bacterial stimulation. These findings suggest that LL-37 displays distinct expression patterns from those of hBDs in gingival tissue.

Adult↗

PubMed2006

Effect of mixed mutans streptococci colonization on caries development.

OBJECTIVE: To evaluate the clinical importance of mixed mutans streptococci colonization in predicting caries in preschool children. METHODS: Caries prevalence was examined twice, with a 6-month interval, in 410 preschool children aged 3-4 years at baseline. A commercial strip method was used to evaluate the mutans streptococci score in plaque collected from eight selected interdental spaces and in saliva. Mutans streptococci typing polymerase chain reaction (PCR) assays (Streptococcus sobrinus and Streptococcus mutans, including serotypes c, e, and f) were performed using colonies on the strips as template. RESULTS: Twenty variables were examined in a univariate analysis to predict caries development: questionnaire variables, results of clinical examination, mutans streptococci scores, and PCR detection of S. sobrinus and S. mutans (including serotypes c, e, and f). Sixteen variables showed statistically significant associations (P < 0.04) in the univariate analysis. However, when entered into a logistic regression, only five variables remained significant (P < 0.05): caries experience at baseline; mixed colonization of S. sobrinus and S. mutans including S. mutans serotypes; high plaque mutans streptococci score; habitual use of sweet drinks; and nonuse of fluoride toothpaste. CONCLUSION: 'Mixed mutans streptococci colonization' is a novel measure correlated with caries development in their primary dentition.

Beverages↗

PubMed2006

Neurolysis is not required for young patients with a spontaneous palsy of the anterior interosseous nerve: retrospective analysis of cases managed non-operatively.

We studied 21 patients with a spontaneous palsy of the anterior interosseous nerve. There were 11 men and 10 women with a mean age at onset of 39 years (17 to 65). Pain around the elbow or another region (forearm, shoulder, upper arm, systemic arthralgia) was present in 17 patients and typically lasted for two to three weeks. It had settled within six weeks in every case. In ten cases the palsy developed as the pain settled. A complete palsy of flexor pollicis longus and flexor digitorum profundus to the index finger was seen in 13 cases and an isolated palsy of flexor pollicis longus in five. All patients were treated without operation. The mean time to initial muscle contraction was nine months (2 to 18) in palsy of the flexor digitorum profundus to the index finger, and ten months (1 to 24) for a complete palsy of flexor pollicis longus. An improvement in muscle strength to British Medical Research Council grade 4 or better was seen in all 15 patients with a complete palsy of the flexor digitorum profundus and in 16 of 18 with a complete palsy of flexor pollicis longus. There was no significant correlation between the duration of pain and either the time to initial muscle contraction or final muscle strength. Prolonged pain was not always associated with a poor outcome but the age of the patient when the palsy developed was strongly correlated. Recovery occurred within 12 months in patients under the age of 40 years who achieved a final British Medical Research Council grade of 4 or better. Surgical decompression does not appear to be indicated for young patients with this condition.

Adolescent↗

PubMed2005

Alpha-synuclein-positive structures induced in leupeptin-infused rats.

Abnormal accumulation of alpha-synuclein is regarded as a key pathological step in a wide range of neurodegenerative processes, not only in Parkinson's disease (PD) and dementia with Lewy bodies (DLB) but also in multiple-system atrophy (MSA). Nevertheless, the mechanism of alpha-synuclein accumulation remains unclear. Leupeptin, a protease inhibitor, has been known to cause various neuropathological changes in vivo resembling those of aging or neurodegenerative processes in the human brain, including the accumulation of neuronal processes and neuronal cytoskeletal abnormalities leading to neurofibrillary tangle (NFT)-like formations. In the present study, we administered leupeptin into the rat ventricle and found that alpha-synuclein-positive structures appeared widely in the neuronal tissue, mainly in neuronal processes of the fimbria and alveus. Immunoelectron microscopic study revealed that alpha-synuclein immunoreactivity was located in the swollen axons of the fimbria and alveus, especially in the dilated presynaptic terminals. In addition colocalization of alpha-synuclein with ubiquitin was rarely observed in confocal laser-scan image. This is the first report of experimentally induced in vivo accumulation of alpha-synuclein in non-transgenic rodent brain injected with a well-characterized protease inhibitor by an infusion pump. The present finding suggests that the local accumulation of alpha-synuclein might be induced by the impaired metabolism of alpha-synuclein, which are likely related to lysosomal or ubiquitin-independent proteasomal systems.

Animals↗

PubMed2005

Partial deletions of the W chromosome due to reciprocal translocation in the silkworm Bombyx mori.

In the silkworm, Bombyx mori (female, ZW; male, ZZ), femaleness is determined by the presence of a single W chromosome, irrespective of the number of autosomes or Z chromosomes. The W chromosome is devoid of functional genes, except the putative female-determining gene (Fem). However, there are strains in which chromosomal fragments containing autosomal markers have been translocated on to W. In this study, we analysed the W chromosomal regions of the Zebra-W strain (T(W;3)Ze chromosome) and the Black-egg-W strain (T(W;10)+(w-2) chromosome) at the molecular level. Initially, we undertook a project to identify W-specific RAPD markers, in addition to the three already established W-specific RAPD markers (W-Kabuki, W-Samurai and W-Kamikaze). Following the screening of 3648 arbitrary 10-mer primers, we obtained nine W-specific RAPD marker sequences (W-Bonsai, W-Mikan, W-Musashi, W-Rikishi, W-Sakura, W-Sasuke, W-Yukemuri-L, W-Yukemuri-S and BMC1-Kabuki), almost all of which contained the border regions of retrotransposons, namely portions of nested retrotransposons. We confirmed the presence of eleven out of twelve W-specific RAPD markers in the normal W chromosomes of twenty-five silkworm strains maintained in Japan. These results indicate that the W chromosomes of the strains in Japan are almost identical in type. The Zebra-W strain (T(W;3)Ze chromosome) lacked the W-Samurai and W-Mikan RAPD markers and the Black-egg-W strain (T(W;10)+(w-2) chromosome) lacked the W-Mikan RAPD marker. These results strongly indicate that the regions containing the W-Samurai and W-Mikan RAPD markers or the W-Mikan RAPD marker were deleted in the T(W;3)Ze and T(W;10)+(w-2) chromosomes, respectively, due to reciprocal translocation between the W chromosome and the autosome. This deletion apparently does not affect the expression of Fem; therefore, this deleted region of the W chromosome does not contain the putative Fem gene.

Animals↗

PubMed2005

Topically administered timolol and dorzolamide reduce intraocular pressure and protect retinal ganglion cells in a rat experimental glaucoma model.

AIMS: This study sought to elucidate the effects of timolol and dorzolamide on intraocular pressure (IOP) and retinal ganglion cell (RGC) death in an experimental model of glaucoma in rat. METHODS: Mild elevation of IOP was induced in rats by intracameral injection of India ink and subsequent laser trabecular photocoagulation. IOP was measured before the surgical procedures and weekly thereafter. Timolol (0.5%), timolol XE (0.5%), dorzolamide (1%), and artificial tears (vehicle) were topically applied daily. Retinal sections were prepared for histology to determine RGC number. RESULTS: Timolol, timolol XE, and dorzolamide induced a significant reduction in IOP (p<0.05) and counteracted the reduction in RGC number that occurred in vehicle treated glaucomatous eyes (p<0.05). The coefficient of correlation between RGC number and IOP was significant in the dorzolamide treated group (r = -0.908, p<0.005), but not in other groups (p>0.05). CONCLUSIONS: Both timolol formulation and dorzolamide reduced IOP and protected RGCs in a rat model of experimental glaucoma. It cannot be ruled out that timolol might protect RGCs by additional mechanisms other than simply lowering of IOP.

Animals↗

PubMed2004

Acute infection with influenza virus enhances susceptibility to fatal pneumonia following Streptococcus pneumoniae infection in mice with chronic pulmonary colonization with Pseudomonas aeruginosa.

We established a mouse model in which fatal pneumonia was induced by pneumococcal superinfection following influenza virus infection in chronic Pseudomonas aeruginosa infected mice. In this mouse model, influenza virus infection caused a significant increase in inflammatory cells, cytokines and severe tissue damage in the lungs of these P. aeruginosa infected mice, before pneumococcal infection. Intrapulmonary virus titres were significantly increased in mice with chronic P. aeruginosa infection, compared with control mice. Neutrophil function analysis showed significant reduction of myeloperoxidase (MPO) activity and lysozyme secretion by influenza virus infection in these mice. Our results suggest that influenza virus infection may play an important role in inducing pneumococcal pneumonia in chronic P. aeruginosa infected mice. Our results suggested that our mouse model is useful for investigating the pathogenesis of influenza virus infection in patients with chronic lung infection.

Acute Disease↗

PubMed2004

Immunokinetics in severe pneumonia due to influenza virus and bacteria coinfection in mice.

Coinfections of bacteria and influenza are a major cause of excessive mortality during influenza epidemics. However, the mechanism of the synergy between influenza virus and bacteria are poorly understood. In this study, mice were inoculated with influenza virus, followed 2 days later by inoculation with Streptococcus pneumoniae. The kinetics of viral titres, bacterial numbers and the immune response (cytokine and chemokine production) were also analysed. Short-term survival correlated with pathological changes in the lungs of infected mice. Influenza virus or S. pneumoniae infection alone induced moderate pneumonia; however, severe bronchopneumonia with massive haemorrhage in coinfected mice, which caused death of these mice approximately 2 days after inoculation with S. pneumoniae, was noted. Intrapulmonary levels of inflammatory cytokines/chemokines, type-1 T-helper cell cytokines and Toll-like receptors, and the related mitogen-activated protein kinase signalling molecules (phosphorylated extracellular signal-regulated kinase -1 and - 2, p38 and c-Jun N-terminal kinase), were increased in coinfected mice. These results suggest that immune mediators, including cytokines and chemokines, through Toll-like receptors/mitogen-activated protein kinase pathways, play important roles in the pathology of coinfection caused by influenza virus and Streptococcus pneumoniae.

Animals↗

PubMed2004

[Familial spontaneous pneumothorax].

A case of familial spontaneous pneumothorax was reported. A 52-year-old man was referred to our hospital complaining of exertional dyspnea. He had experienced right spontaneous pneumothorax and cured with tube drainage last year. Five of his 7 brothers and his son too had had spontaneous pneumothorax. Chest X-ray film and computed tomography (CT) scan on admission showed giant bulla of the left lung with compression of normal lungs. Pulmonary function studies revealed obstructive pulmonary disease and mild hypoxemia. Partial resection of the lung with open thoracotomy surgery was performed. Air leaks sealed in 14 days and the patient discharged the hospital with inadequate expansion of the left lung. Three years later the patient experienced right hemicolectomy for colon cancer and died for recurrence 7 years later with adequate expansion of the left lung.

Humans↗

PubMed2004

[Probable toxic shock syndrome following pleural drainage].

Toxic shock syndrome (TSS) is rare complication after minor surgical procedure. A 22-year-old man was admitted our hospital with spontaneous pneumothorax on the right side. Few days after pleural drainage, he developed a high fever often over 40 degrees C and a rash, most demonstrating a truncal, "sunburn" pattern. Initially, he was diagnosed as right pylothorax, but the clinical course was not typical and antibiotic treatment was not effective. Two weeks later, desquamation of the hands and feet were noted, and methicillin-resistant Staphylococcus aureus (MRSA) isolated from the pleural effusion were identified as TSS toxin (TSST)-1 and enterotoxin-C producing. He was diagnosed as probable TSS, and recovered by steroid therapy. Early awareness and recognition of this disease is necessary for surgeons.

Adult↗

PubMed2003

Evaluation of mutans streptococci in plaque and saliva: correlation with caries development in preschool children.

OBJECTIVES: To test the ability of a site-specific method of evaluating mutans streptococci (MS) present in plaque in order to predict caries risk in children and to compare the results with those obtained from estimating the levels of MS present in saliva. METHODS: Caries prevalence was examined twice, 6 months apart, in 129 preschool children ranging in age from 1.5 to 5. A commercial strip method was used to evaluate the MS score (0-3) in plaque collected from four selected tooth surfaces at two interdental spaces and in saliva. RESULTS: The screening criteria of the MS score for caries incidence between scores 1 and 2, and scores 0 and 1 were the most valid for evaluating plaque (accuracy of prediction, 80%) and saliva (accuracy of prediction, 71%), respectively. Based on these screening criteria, the evaluation of saliva MS was invalid when the plaque MS score was considered. Screening plaque MS was effective, regardless of caries experience at baseline, according to the chi-square test (p<0.01), but screening saliva MS was ineffective when caries experience was present at baseline. A multivariate logistic regression analysis including six variables showed that the plaque MS score and caries experience at baseline were significantly correlated with caries incidence: caries experience at baseline (OR=5.02, 95%CI: 1.81-14.59) and high plaque MS score (2 or 3) (OR=12.59, 95%CI: 3.18-67.08). CONCLUSIONS: These results suggest that the semi-quantitative evaluation of plaque MS sampled from only two proximal sites on the molars is more effective for screening preschool children at a high risk of developing caries in their primary dentition than other important caries risk indicators.

Chi-Square Distribution↗

PubMed2003

[Successful emergent replacement of ruptured aortic arch aneurysm in an inpatient waiting for surgery: report of a case].

A 71-year-old male was admitted to our hospital for examination of mediastinal abnormal shadow, which was diagnosed aortic arch aneurysm. Once he was discharged and stayed at home for 2 weeks, and then re-admitted for surgery. On the 3rd day of 2nd admission, he suddenly fainted away in the ward and was in shock by hemorrhagic cardiac tamponade. He was transferred to operation room within an hour from onset of rupture. Emergent aortic arch replacement was performed under circulatory arrest with deep hypothermia and retrograde cerebral perfusion. His postoperative course was uneventful without any neurological deficits. Prompt diagnosis and surgery may contribute to improvement of surgical result in patients with ruptured aortic arch aneurysms.

Aged↗

PubMed2003

[Hemodynamic collapse during off-pump coronary artery bypass grafting and optimization].

The present study addressed the incidence of unpredicted hemodynamic collapse in off-pump coronary artery bypass grafting (OPCAB). Since 1999, OPCAB was attempted in 114 patients without preoperative hemodynamic collapse to date. 95% patients of OPCAB were completed without percutaneous cardiopulmonary support (PCPS) and all patients were discharged. In this study, patients are divided into a prophase of 60 patients and an anaphase of 50 patients, in consideration of learning curve. As for the trouble in procedures, 12 patients of ventricular fibrillation, 6 patients of conversion to PCPS, 19 patients of bradycardia which were evaded in temporary pacing were observed. Patients with conversion to PCPS decreased in 5 patients (8%) in prophase and 1 patient (1.8%) in anaphase. Avoidance of hemodynamic collapse were prevention of ischemia by positive use of coronary perfusion, prophylactic intra-aortic balloon pumping (IABP) use for decrease of blood pressure, apical evacuation heart positioner for visual field security.

Adult↗

PubMed2003

The role and expression of CD27 and CD70 lymphocytes in the human tonsil.

In this study, we investigated the expression and function of CD27 and CD70 in the human tonsil. We found that IgG production was significantly reduced after the administration of anti-CD27 and anti-CD70 antibodies in the T cell dependent B cell activation system, suggesting the involvement of CD27/CD70 in the production of IgG. In addition, the amounts of peripheral and tonsililar CD4+ CD27+ cells were almost identical, whereas the expression of CD4+ CD27- cells was higher (4.9%) in tonsil than in peripheral blood (2.4%). Furthermore, anti-CD27 antibody and anti-CD4 antibody-positive cells were found mainly in the interfollicular region, and a small number of this cell population was observed in both germinal center (GC) and mantle. Double-staining showed that the germinal center was almost completely composed of CD4+ CD27+ cells. In contrast to CD27 cells, only a small number of CD70+ cells were present in the follicles. Moreover, anti-CD19 antibody, a B cell marker, was stained in the GC and mantle zone, and CD19+ CD27+ cells were observed in the GC close to the mantle. The above findings favor the involvement and role of CD27/CD70 in the T-B cell interaction by inducing IgG production and increasing memory cell (CD4+ CD27-) number in the tonsil.

Antigens, CD↗

PubMed2002

The product of Saccharomyces cerevisiae WHIP/MGS1, a gene related to replication factor C genes, interacts functionally with DNA polymerase delta.

The Saccharomyces cerevisiae gene WHIP/ MGS1 encodes a protein related to the subunits of Replication Factor C (RFC). We found that the RFC-like motifs in Whip/Mgs1 are essential for its function. Furthermore, by screening for synthetic dosage lethality, we have shown that overexpression of MGS1 causes lethality in combination with mutations in genes that encode replication proteins such as DNA polymerase delta, RFC, PCNA and RPA. Moreover, loss of MGS1 function interferes with the ability of multicopy PCNA to suppress the replication defect of the rfc5-1 mutant. At permissive temperatures, deletion of MGS1 suppresses the hydroxyurea (HU) sensitivity of pol31 and pol32 mutants, which bear mutations in the smaller subunits of DNA polymerase delta, and at semipermissive and non-permissive temperatures mgs1delta partially alleviates the growth defects of the pol31 mutant. We also report that the growth defect and HU sensitivity of the pol31 mutant are suppressed by mms2delta and rad18delta mutations. We suggest that Mgs1 interacts with the DNA replication machinery to modulate the function of DNA polymerase delta during replication or replication-associated repair, and influences the choice of the pathway employed for replication fork reactivation. Possible roles of Mgs1, DNA polymerase delta, Rad18 and Mms2 in replication and replication fork restart are discussed.

Adenosine Triphosphatases↗

PubMed2002

Evolution of lower-hybrid-driven current during the formation of an internal transport barrier.

Evolution of the lower-hybrid(LH)-driven current profile was measured during the formation of an internal transport barrier (ITB) in a reversed magnetic shear discharge. As the ITB developed, the initially centrally peaked LH-driven current profile gradually turned hollow and was sometimes accompanied by an off-axis peak in the electron temperature profile. These observations indicate the concentration of LH power deposition to the ITB for this case as a result of nonlinear coupling between the LH waves and the target plasma.

Journal Article↗