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Biomedical subjects

M Kihara

Publications and source records attributed to M Kihara.

At least 19 recordsLinked to original sources
PubMed2001

Autonomic consequences of brainstem infarction.

OBJECTIVE: It is well known that patients with brainstem infarctions sometimes experience dizziness, vertigo and falls, although the exact mechanism is not clear. Therefore, we designed a study to quantify autonomic function in patients with brainstem infarction. PATIENTS AND METHODS: We examined autonomic function in 15 patients with brainstem infarctions, who had a history of vertigo, nausea, floating sensation and/or general fatigue during standing, and 31 age-matched controls using the composite autonomic scoring scale (CASS), which was used to grade autonomic function. The patients underwent initial autonomic assessment and then were subjected to aniracetam therapy. The drug was given orally (dose of 600 mg/day) for a duration of 56 days. Upon completion of aniracetam administration, the CASS was again tested. RESULTS: Upon initial assessment, the patients had mild reductions in mean blood pressure (MBP) and lack of an increasing heart rate (HR) within 5 min of head up-tilt, an impairment in BP correction during late phase II and reduced phase IV beat-to-beat BP response to the Valsalva maneuver, and reduced heart rate response to deep breathing (HRdb). CASS indicated mild autonomic dysfunction. After 8 weeks of treatment with aniracetam, the patients' symptoms improved and the autonomic tests showed improvement in autonomic function. CONCLUSION: Part of the pathogenesis of recurrent vertigo or dizziness with brainstem infarction might be due to mild autonomic dysfunction. Aniracetam, which activates the cholinergic system in brain, might correct the cardiovagal system in these patients. The CASS may be a sensitive tool for assessing mild autonomic dysfunction in patients with brainstem infarction.

Aged↗
PubMed2001

Antimicrobial activity of Castanopsis acuminatissima.

The methanol extracts of Castanopsis acuminatissima leaves, stem and root barks were partitioned (petrol, dichloromethane, ethyl acetate). Though all of the crude methanolic extracts and obtained fractions from them, showed a broad spectrum of antibacterial activity, in most cases the activity was decreased on fractionation. None was active against tested moulds.

Animals↗
PubMed2001

Antimicrobial activity of Harpullia ramiflora.

The methanol extracts of Harpullia ramiflora, leaves, flowers, stem and root barks were partitioned (petrol, dichloromethane, ethyl acetate). In respect to crude extracts, all fractions demonstrated broader spectrum and higher levels of antibacterial activity. The ethyl acetate fraction of the flowers exhibited the highest activity. No activity was shown against the tested moulds.

Animals↗
PubMed2001

Antimicrobial activity of Omalanthus nervosus.

The ethanol extracts of Omalanthus nervosus leaves, stem and root barks, were partitioned (petrol, dichloromethane, ethyl acetate). In respect to crude extracts, all fractions demonstrated broader spectrum and higher levels of antibacterial activity, ethyl acetate fractions being in all cases the more active. No fraction was active against tested moulds.

Animals↗
PubMed2001

Intergenic suppression between the flagellar MS ring protein FliF of Salmonella and FlhA, a membrane component of its export apparatus.

The MS ring of the flagellar basal body of Salmonella is an integral membrane structure consisting of about 26 subunits of a 61-kDa protein, FliF. Out of many nonflagellate fliF mutants tested, three gave rise to intergenic suppressors in flagellar region II. The pseudorevertants swarmed, though poorly; this partial recovery of motile function was shown to be due to partial recovery of export function and flagellar assembly. The three parental mutants were all found to carry the same mutation, a six-base deletion corresponding to loss of Ala-174 and Ser-175 in the predicted periplasmic domain of the FliF protein. The 19 intergenic suppressors identified all lay in flhA, and they consisted of 10 independent examples at the nucleotide level or 9 at the amino acid level. Since two of the nine corresponded to different substitutions at the same amino acid position, only eight positions in the FlhA protein have given rise to suppressors. Thus, FliF-FlhA intergenic suppression is a fairly rare event. FlhA is a component of the flagellar protein export apparatus, with an integral membrane domain encompassing the N-terminal half of the sequence and a cytoplasmic C-terminal domain. All of the suppressing mutations lay within the integral membrane domain. These mutations, when placed in a wild-type fliF background, had no mutant phenotype. In the fliF mutant background, mutant FlhA was dominant, yielding a pseudorevertant phenotype. Wild-type FlhA did not exert significant negative dominance in the pseudorevertant background, indicating that it does not compete effectively with mutant FlhA for interaction with mutant FliF. Mutant FliF was partially dominant over wild-type FliF in both the wild-type and second-site FlhA backgrounds. Membrane fractionation experiments indicated that the fliF mutation, though preventing export, was mild enough to permit assembly of the MS ring itself, and also assembly of the cytoplasmic C ring onto the MS ring. The data from this study provide genetic support for a model in which at least the FlhA component of the export apparatus physically interacts with the MS ring within which it is housed.

Amino Acid Substitution↗
PubMed2000

A mid-term follow-up of medial patellofemoral ligament reconstruction using an artificial ligament for recurrent patellar dislocation.

A prospective study on medial patellofemoral ligament reconstruction for recurrent patellar dislocation was performed. At an average follow-up of 5.9 years, 27 MPFL reconstructions using a mesh-type artificial ligament and medial retinaculum slip coverage were reviewed using the Crosby and Insall grading system. Fifteen knees (55%) were classified as excellent, 11 knees (41%) as good, 1 knee (4%) as fair/poor and none as worse. At a mid-term follow-up, medial patellofemoral ligament reconstruction should be considered as a safe and effective operation.

Journal Article↗
PubMed2000

Characterization of the yeast Cdc7p/Dbf4p complex purified from insect cells. Its protein kinase activity is regulated by Rad53p.

The yeast Saccharomyces cerevisiae Cdc7p/Dbf4p protein kinase complex was purified to near homogeneity from insect cells. The complex efficiently phosphorylated yeast Mcm2p and less efficiently the remaining Mcm proteins or other replication proteins. Significantly, when pretreated with alkaline phosphatase, Mcm2p became completely inactive as a substrate, suggesting that it must be phosphorylated by other protein kinase(s) to be a substrate for the Cdc7p/Dbf4p complex. Mutant Cdc7p/Dbf4p complexes containing either Cdc7-1p or Dbf4-1 approximately 5p were also partially purified from insect cells and characterized in vitro. Furthermore, the autonomously replicating sequence binding activity of various dbf4 mutants was also analyzed. These studies suggest that the autonomously replicating sequence-binding and Cdc7p protein kinase activation domains of Dbf4p collaborate to form an active Cdc7p/Dbf4p complex and function during S phase in S. cerevisiae. It is shown that Rad53p phosphorylates the Cdc7p/Dbf4p complex in vitro and that this phosphorylation greatly inhibits the kinase activity of Cdc7p/Dbf4p. This result suggests that Rad53p controls the initiation of chromosomal DNA replication by regulating the protein kinase activity associated with the Cdc7p/Dbf4p complex.

Alkaline Phosphatase↗
PubMed2000

Population-based mapping of pulmonary adenoma susceptibility 1 locus.

Pulmonary adenoma susceptibility 1 (Pas1), the major locus affecting inherited predisposition to lung tumor development in mice, maps near the Kras2 gene. We previously reported a significant association between a KRAS2/RsaI polymorphism and the risk and prognosis of lung adenocarcinoma (ADCA) in the Italian population. In the present case-control study, we examined 269 lung ADCA patients, 121 squamous cell lung carcinoma patients, and 632 healthy individuals (general population controls) in the Japanese population with genetic markers spanning approximately 1200 kb in the KRAS2 region. Allele-specific oligonucleotide hybridization revealed the same KRAS2/RsaI polymorphism associated with risk and prognosis as in Italian lung ADCA patients; the polymorphism was significantly associated with clinical stage (P < 0.001) and survival rate (log rank = 0.0014), confirming the mapping of PAS1 and pointing to the role of this locus in human lung cancer.

Adenocarcinoma↗
PubMed2000

Medial patellofemoral ligament restraint in lateral patellar translation and reconstruction.

The purpose of this investigation was to evaluate the prevention of lateral patellar displacement by the medial patellar stabilizers and the effectiveness of medial patellofemoral ligament (MPFL) reconstruction against lateral displacement. Ten fresh frozen human knee specimens were studied and anatomical observations were made using seven additional knee specimens. Lateral shift ratios were measured, using a lateral force of 10 N, after sectioning the medial retinaculum and/or the MPFL during 20-120 degrees of knee flexion. The isolated sectioning of the MPFL greatly increased lateral displacement during 20-90 degrees, and the isolated MPFL reconstruction prevented patellar displacement within the normal range during 20-120 degrees.

Journal Article↗
PubMed2000

Aging differentially modifies sensitivity of nerve blood flow to vasocontractile agents (endothelin-1, noradrenaline and angiotensin II) in sciatic nerve.

This study examined the influence of the vaso-constricting agents (noradrenaline, endothelin-1 and angiotensin II) in Sprague-Dawley rats aged 2, 6 and 24 months by evaluating epineurial arteriolar vasoreactivity in response to superfused teat agents. Nerve blood flow (NBF) was measured using microelectrode H2 polarography. In 24-month-old rats, NBF was decreased and vascular resistance (VR) was increased compared with 2- and 6-month-old rats. All of the constricting agents reduced NBF in the 2-, 6- and 24-month groups, however, the effects of the constricting agents reduced significantly with age. These results suggest that during aging, there is a decline of vasoconstrictive responses to noradrenaline, endothelin-1 and angiotensin II in peripheral nerve and that these changes may be due to altered function of receptors.

Aging↗
PubMed2000

Recovery of parathyroid function after total thyroidectomy.

To prevent postoperative hypoparathyroidism following total thyroidectomy, the parathyroid glands are preserved in situ and/or resected or devascularized parathyroid glands are autotransplanted. We conducted a retrospective investigation utilizing biochemical and specific endocrine assessments to evaluate the difference in recovery of parathyroid function between the two operative methods. A total of 92 patients underwent total thyroidectomy at our hospital during the period between 1990 and 1997. These patients were divided into a preservation group (n = 83), with one or more preserved glands in situ, and an autotransplantation group (n = 9), with only transplanted glands. The level of intact parathyroid hormone (PTH) was completely restored by 1 year postoperatively in 83% (69/83) of the preservation group patients. In the remaining 14 patients (17%), the intact PTH had fallen below detectable levels on postoperative day (POD) 1, then subsequently recovered to 70% of the preoperative levels. Comparatively, in the autotransplantation group, the mean level of intact PTH recovered to only 43% of the preoperative levels. The results of this study suggest that parathyroid glands should be preserved in situ whenever possible, and that when intact PTH levels fall below detectable limits on POD 1, they may never recover to the preoperative levels in those patients.

Adenocarcinoma, Follicular↗
PubMed2000

Phytochemical flavones isolated from Scutellaria barbata and antibacterial activity against methicillin-resistant Staphylococcus aureus.

A crude extract prepared from Scutellaria barbata D. Don (Lamiaceae) was analyzed in the effort to discover antibacterial compounds against high-level strains of methicillin-resistant Staphylococcus aureus (MRSA). Apigenin and luteolin were isolated from the plant as active constituents against the bacteria. These flavonoid congeners were selectively toxic to S. aureus, including the MRSA and methicillin-sensitive S. aureus strains.

Anti-Bacterial Agents↗
PubMed2000

Deletion analysis of the flagellar switch protein FliG of Salmonella.

The flagellar motor/switch complex, consisting of the three proteins FliG, FliM, and FliN, plays a central role in bacterial motility and chemotaxis. We have analyzed FliG, using 10-amino-acid deletions throughout the protein and testing the deletion clones for their motility and dominance properties and for interaction of the deletion proteins with the MS ring protein FliF. Only the N-terminal 46 amino acids of FliG (segments 1 to 4) were important for binding to FliF; consistent with this, an N-terminal fragment consisting of residues 1 to 108 bound FliF strongly, whereas a C-terminal fragment consisting of residues 109 to 331 did not bind FliF at all. Deletions in the region from residues 37 to 96 (segments 4 to 9), 297 to 306 (segment 30), and 317 to 326 (segment 32) permitted swarming, though not at wild-type levels; all other deletions caused paralyzed or, more commonly, nonflagellate phenotype. Except for those near the N terminus, deletions had a dominant negative effect on wild-type cells.

Bacterial Proteins↗
PubMed2000

Large and asymptomatic pancreatic islet cell tumor in a patient with multiple endocrine neoplasia type 1.

The major phenotypes of multiple endocrine neoplasia type 1 (MEN 1) consist of three lesions characterized by hyperparathyroidism, pituitary tumors, and endocrine pancreatic tumors. The endocrine pancreatic tumors are a significant cause of disease-related mortality in MEN 1. Although symptomatic pancreatic tumors such as insulinoma and gastrinoma should be resected, the management of asymptomatic pancreatic tumors is not established. In asymptomatic pancreatic tumors, the most important factor is the propensity for malignant transformation of the tumors. Although there are no means to foresee it, the size of the pancreatic tumors might be predictive of malignant development in MEN 1. We report here a patient with MEN 1 who had a large asymptomatic pancreatic tumor. The patient (72-yr-old man) was diagnosed with primary hyperparathyroidism and underwent a total parathyroidectomy. Genetic examination showed a germline mutation of the MEN1 gene (E45G). Abdominal magnetic resonance imaging revealed a large (>6 cm) tumor with a heterogeneous pattern in the tail of the pancreas. No metastases of the tumor were evident. Serum levels of insulin, gastrin, and glucagon were normal, and the patient had no symptoms. Operative resection was performed, and microscopic examination revealed that the tumor was an islet cell tumor stained with multiple hormones. This is a case indicating that asymptomatic pancreatic tumors associated with MEN 1 might be indolent independent of their size.

Adenoma, Islet Cell↗
PubMed2000

Delays and continuation of hospital visits among HIV-infected persons and AIDS cases in Japan.

This study attempts to clarify the distribution patterns of delay between HIV transmission and the first hospital visit among HIV-infected persons and AIDS cases in Japan except those infected through blood products. Such hospital visit patterns were analyzed, and the rates of reporting for HIV/AIDS surveillance among diagnosed HIV-infected persons and AIDS cases in hospitals were shown. From 1991 to 1997, a survey and subsequent follow-up were conducted among HIV-infected persons and AIDS cases diagnosed at 74 hospitals in Tokyo. The numbers of HIV-infected persons and AIDS cases were 590 and 208, respectively. The percentage of patients whose estimated date of HIV transmission was obtained ranged 23-41% among Japanese and non-Japanese HIV-infected persons and AIDS cases. Among these patients, 28% to 86% showed a 3-year delay between HIV transmission and their first hospital visit. The rate of HIV-infected persons who continued to visit hospitals within 1 year after their first visit was 77% for Japanese and 45% for non-Japanese; among those after 1 year or more following their first hospital visit the rate was more than 80% among Japanese and over 70% among non-Japanese. The rate of reporting to HIV/AIDS surveillance among diagnosed HIV-infected persons and AIDS cases was 90% or more after 1994 in Japan. The delay between HIV transmission and the first hospital visit was suggested to be very long. Not a few patients stopped visiting hospitals after only a short time. Most diagnosed HIV-infected persons and AIDS cases were reported to the surveillance system of Japan.

HIV Infections↗
PubMed1999

Effects of ethanol on neuronal migration and neural cell adhesion molecules in the embryonic rat cerebral cortex: a tissue culture study.

To investigate whether ethanol has direct effects on neuronal migration in the cerebral cortex, we performed a tissue culture study using embryonic rat brain with thymidine autoradiography. After we labeled progenitor cells in the ventricular zone of E16 cerebral cortex explants with [3H]thymidine, the explants were cultured for 48 h, and then distribution of labeled cells was evaluated autoradiographically. Adding 3.0 or 6.0 mg/ml ethanol to the culture medium caused significantly decreased distribution of labeled cells in the outer intermediate [control: 2.0+/-0.6% (mean+/-S.D.); 1.0 mg/ml ethanol: 2.1+/-1.5%; 3.0 mg/ml ethanol: 0. 5+/-1.5% (P<0.05); 6.0 mg/ml ethanol: 0.4+/-0.5% (P<0.05)] and the inner intermediate-A zones [control: 19.5+/-6.2%; 1.0 mg/ml ethanol: 13.1+/-8.6%; 3.0 mg/ml ethanol: 3.0+/-3.4% (P<0.01); 6.0 mg/ml ethanol: 5.2+/-2.9% (P<0.01)] compared to the control group. The mitotic index after 48-h culture was significantly reduced in the 6. 0 mg/ml ethanol group (0.260+/-0.114%; P<0.01) compared to the control group (0.600+/-0.158%). This suggests that ethanol inhibits neuronal migration in the cerebral cortex, although prolongation of the cell cycle by ethanol may contribute to the decreased number of labeled cells in the outer intermediate and inner intermediate-A zones. Furthermore, an abnormally dense and tortuous staining pattern of immunoreactive products of N-CAM was seen on the surface of migrating neurons in the 3.0 and 6.0 mg/ml ethanol groups, while the L1 staining pattern did not differ between the control and ethanol groups. These results suggest that abnormal expression of N-CAM may be involved in the inhibition of neuronal migration by ethanol.

Animals↗