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Biomedical subjects

M Doi

Publications and source records attributed to M Doi.

At least 145 records · Page 8Linked to original sources
PubMed1996

Fibrinogen, coagulation factor VII, tissue plasminogen activator, plasminogen activator inhibitor-1, and lipid as cardiovascular risk factors in chronic hemodialysis and continuous ambulatory peritoneal dialysis patients.

Mortality rates associated with cardiovascular disease (CVD) are high in long-term dialysis patients. Increased levels of plasma fibrinogen (FBG), coagulation factor VII (FVII), tissue plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1) as well as hyperlipidemia are regarded as important risk factors for CVD. To investigate whether there are differences in the risk of CVD between chronic hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD) patients, serum lipid levels and plasma FBG, FVII, t-PA, and PAI-1 levels were measured in 17 patients on HD and 17 patients on CAPD. FBG was measured by the thrombin time method, FVII activity (FVIIc) by the chromogenic prothrombin time method, and t-PA and PAI-1 activity by the chromogenic substrate assay. No difference was found in body mass index (BMI) between HD and CAPD patients. Total cholesterol (TC), TC/high-density lipoprotein (HDL)-C ratio, low-density lipoprotein (LDL)-C, and triglycerides (TG) were significantly increased, and HDL-C was significantly decreased in CAPD patients compared with HD patients. FBG and FVIIc were significantly elevated in CAPD patients compared with controls or HD patients. T-PA activities were significantly higher in HD and CAPD patients than in controls. CAPD patients showed significantly higher PAI-1 activities than controls or HD patients. Significant positive correlations were found between FBG or FVIIc and TC, between FBG and LDL-C or TG, and between FVIIc and LDL-C in these patients. T-PA showed significant negative correlations with FBG, PAI-1, TC, LDL-C, and TG. There was a significant positive correlation between PAI-1 and TG and a significant negative correlation between PAI-1 and HDL-C. We conclude that CAPD patients may have a greater risk of CVD than do HD patients, and that coagulation and fibrinolytic activity are correlated with lipid disorders in these patients.

Adult↗
PubMed1996

Genetic analysis of Drosophila virilis sex pheromone: genetic mapping of the locus producing Z-(11)-pentacosene.

Z-(11)-pentacosene, Drosophila virilis sex pheromone, is predominant among the female cuticular hydrocarbons and can elicit male courtship behaviours. To evaluate the genetic basis of its production, interspecific crosses between D. novamexicana and genetically marked D. virilis were made and hydrocarbon profiles of their backcross progeny were analysed. The production of Z-(11)-pentacosene was autosomally controlled and was recessive. Of the six D. virilis chromosomes only the second and the third chromosomes showed significant contributions to sex pheromone production, and acted additively. Analysis of recombinant females indicated that the locus on the second chromosome mapped to the proximity of position 2-218.

Alkenes↗
PubMed1996

Endothelium-dependent relaxation and vasospasm in the single-hemorrhage canine model.

We have investigated the relationship between angiographic vasospasm and the ability of spastic vessels to relax in response to agents which promote release of endothelium derived relaxing factor. Vasospasm was induced in dogs by the 'single hemorrhage' technique. Animals received a single intracisternal injection of blood, blood activated with thromboplastin or collagen, or inert material, and angiograms were obtained day 0 and day 7. Vasospasm was estimated by measuring the ratio of the diameter of the vessel before and after treatment. Rings of cerebral artery obtained from these animals were suspended in a standard organ-bath arrangement, contracted with prostaglandin F2 alpha and then treated with increasing doses of adenosine triphosphate or bradykinin, both of which cause relaxation by an endothelium-dependent process. The arteries from animals with moderate to severe vasospasm showed a response to bradykinin and adenosine-triphosphate which was reduced, absent or converted to a contraction, when compared with normal vessels. Vessels in which vasospasm was mild or absent relaxed as expected to these agents. The reduction in vessel diameter showed a highly significant correlation with the reduction in relaxation to bradykinin or adenosine-triphosphate. These results have demonstrated that impairment of endothelium-dependent vasorelaxation correlates with the existence of vasospasm.

Adenosine Triphosphate↗
PubMed1996

Crystallization and preliminary X-ray diffraction study of recombinant human eukaryotic initiation factor-4E.

Recombinant human eukaryotic initiation factor-4E (eIF-4E), purified by m7GTP-Sepharose 4B affinity chromatography, was used for crystallization. After concentration of the eIF-4E protein (7 mg/ml), the solution was subjected to crystallization by the hanging-drop method. Transparent needle crystals complexed with m7GTP were obtained from 50 mM 2-(N-morpholino)ethanesulfonic acid-KOH buffer (pH 6.5) containing 25% (w/v) polyethylene glycol 6000 and 0.2 M (NH4)2SO4. The crystals belong to tetragonal space group P4(1) or P4(3), of Z = 4, with unit-cell dimensions of a = 89.26, b = 89.26, and c = 38.51 angstrum, and diffract beyond 2.1 angstrum resolution. The Vm value was calculated to be 3.07 angstrum 3/Da, which indicates a solvent content of 59.9%.

Crystallization↗
PubMed1996

Stellate ganglion block is associated with increased tibial nerve muscle sympathetic activity in humans.

BACKGROUND: Left stellate ganglion block has been shown to increase heart rate and blood pressure, possible because of blockage of afferent vagal fibers from arterial baroreceptors in the aortic arch. Because efferent muscle sympathetic nerve activity (MSNA) is influenced by the arterial baroreflex, the hypothesis that left stellate ganglion block increases efferent MSNA recorded from the tibial nerve of humans was tested. METHODS: Twenty healthy male volunteers were sequentially assigned to one of three groups: stellate ganglion block (n = 10), in which 7 ml 1% mepivacaine was injected into the left stellate ganglion; placebo (n = 5), in which 7 ml of saline was injected into the left stellate ganglion; and intramuscular injection (n = 5), in which 7 ml mepivacaine was injected into the left deltoid muscle. Direct intraneural microneurographic recording with a tungsten microelectrode was used to record MSNA in the left tibial nerve. MSNA, heart rate, and blood pressure were recorded before and after injection in all groups. An additional five volunteers were studied with transthoracic echocardiography to examine the effect of stellate ganglion block on preload changes. RESULTS: Tibial nerve MSNA increased after mepivacaine injection to the left stellate ganglion but was unchanged after saline injection to the left stellate ganglion or mepivacaine injection into the deltoid muscle. Heart rate increased significantly after the left stellate ganglion block but did not change significantly after saline injection to the left stellate ganglion or after mepivacaine injection to the deltoid muscle. Systemic blood pressure did not change significantly in all groups. Left ventricular end-diastolic area and left ventricular end-diastolic circumference did not change after stellate ganglion block. CONCLUSIONS: Tibial nerve MSNA increased during left stellate ganglion block with mepivacaine.

Adult↗
PubMed1996

Structural versatility of peptides from C alpha, alpha-disubstituted glycines: crystal-state conformational analysis of peptides from C alpha-methylhomophenylalanine, (alpha Me) Hph.

The molecular and crystal structures of the C alpha-tetrasubstituted, delta-branched alpha-amino acid C alpha-methylhomophenylalanine, H-D-(alpha Me)Hph-OH, and three peptides (to the pentamer level), including the homotripeptide, have been determined by X-ray diffraction. The peptides are Z-L-(alpha Me)Hph-(L-Ala)2-OMe pBrBz-[D-(alpha Me)Hph]3-OtBu and Ac-(Aib)2-L-(alpha Me)Hph-(Aib)2-OtBu. All the (alpha Me)Hph residues prefer phi, psi torsion angles in the helical region of the conformational map. The two terminally blocked tripeptides adopt a beta-bend conformation stabilized by a 1<--4 C = O... H-N intramolecular H-bond. The terminally blocked pentapeptide is folded in a regular 3(10)-helix. In general, the relationship between (alpha Me)Hph alpha-carbon chirality and helix handedness is the same as that exhibited by protein amino acids. A comparison is also made with the conclusions extracted from published work on peptides from other types of C alpha-alkylated aromatic alpha-amino acids.

Aminobutyrates↗
PubMed1996

Differential effects of fibronectin-derived oligopeptides on the attachment of rabbit lens epithelial cells in vitro.

Among the Arg-Gly-Asp (RGD)-containing sequences that are known to be cell-binding domains of fibronectin, 500 migrograms/ml of Arg-Gly-Asp-Ser (RGDS) and Gly-Arg-Gly-Asp-Ser showed 100% inhibition of the attachment of cultured lens epithelial cells (TOTL-86 cells), when they were added to culture medium and coincubated with the cells for 24 h whereas RGD at concentrations of 500, 1,000 and 2,000 micrograms/ml had no such activity. After 48 h of cocultivation of 800, 400 or 200 micrograms/ml of RGDS with TOTL-86 cells, the percentage of floating cells was 100, 30.1 or 11.1%, respectively. After 144 h of cocultivation with RGDS, the percentage of floating cells was 1.6, 2.4 or 1.9%, respectively, indicating that RGDS was not cytotoxic to lens epithelial cells. However, replacing the medium with fresh medium containing new RGDS peptide resulted in floating of cells. We also studied the inhibitory effect of two other amino acid sequences that are found in cell-binding sites of the fibronectin molecule: Glu-Ile-Leu-Asp-Val-Pro-Ser-Thr (EILDVPST) and Arg-Glu-Asp-Val (REDV). At 500 and 1,000 micrograms/ml, respectively, neither EILDVPST nor REDV has an inhibitory effect on the attachment of TOTL-86 cells, while RGDS at a concentration of 500 micrograms/ml completely inhibited the attachment of the cells in 24 h of incubation.

Amino Acid Sequence↗
PubMed1996

Large right ventricular myxoma in a 79-year-old male.

A 79-year-old male, admitted because of severe dyspnea on exertion, showed echocardiographic findings of a large tumor in the dilated right ventricle. The right ventricular outflow tract was nearly occluded by the tumor mass, and the mass was attached to the interventricular septum by a pedicle. The tumor removal operation was successful. The size of the tumor was 40 mm x 90 mm, and the weight 70 g. Microscopic findings showed typical myxomatous tissue with high cellularity, and no malignancy was observed. This is the oldest reported patient with right ventricular myxoma which was cured by operation.

Aged↗
PubMed1996

[Policy for children with chronic neurological diseases].

QOL for children with chronic neurological diseases (CND) depends mainly on the supporting system of children's development and respite measurements of their families. For supporting children's development with CND and for alleviating the burden on the family members, various staffs are needed such as pediatricians, nurses, psychologists, OT, PT, home helpers, etc. Especially children with CND are living at home needs in-home services supplied by these supporting staffs. An in-home care service center is desirable to be established in their living area. According to the maternal and child health law and child welfare law, several measures have been adopted, but these services are not available for children with CND and their family, without registration as handicapped children. All these children should be treated because they have the same problems as physically or mentally handicapped children. The capability of the medical and social service supply has been influenced by recent decrease of the birth rate and improvement of the level in the maternal and child health. The number of facilities, such as pediatric clinics or nursing homes for physically handicapped children, is decreasing because of poor profit. These trends will be continued if appropriate measurements are not introduced. The final estimation of need and supply must be made at the local community level.

Child↗
PubMed1996

[Tuberculous aneurysm of the descending aorta--successful surgical treatment].

A 62-year-old woman visited her primary physician because of high fever and vomiting. From a chest roentgenogram miliary tuberculosis was diagnosed. Anti-tuberculosis drugs were prescribed. Mycobacterium tuberculosis was cultured from samples of sputum. Although she took drugs for 3 months, her symptoms did not resolve and back pain developed. A chest roentgenogram showed an egg-sized mass in the posterior part of the mediastinum. Examination of a chest CT scan showed that the mass was an aortic aneurysm. A graft replacement was done, and histologic examination of the resected specimen showed that it was a tuberculous aneurysm of the descending aorta. Her symptoms disappeared, and she recovered fully. Tuberculous aneurysms are rare: they account for only 0.3% of all aneurysms. This is only the 9th reported case of tuberculous aneurysm successfully treated with surgery in Japan. We must realize that aneurysms are life-threatening complication of miliary tuberculosis.

Aortic Aneurysm, Thoracic↗
PubMed1996

[The indications for postoperative adjuvant therapy in node-negative breast cancer patients].

A clinicopathological study on prognosis has been carried out in 233 breast cancer patients with more than twenty inspected nodes and without lymph node metastasis. Multivariate analysis of clinicopathological findings in node-negative breast cancers showed that the best combination of clinical features predicting prognosis were age, menstruation status, tumor location and tumor diameter; and from 11 pathological features, three factors (histological type, histological grade and the grade of tumor infiltrating lymphocytes) were selected under condition of p<0.05. With solid-tubular carcinoma, histological grade III and negative tumor infiltrating lymphocytes as the 3 poor prognostic factors, node-negative breast cancers were classified. The recurrence rates of subgroups with the number of 3, 2, 1 and 0 were 28%, 16%, 7% and 0%, respectively. We conclude that the grade of tumor infiltrating lymphocytes is especially significant as the prognostic factor in node-negative breast cancers, and that postoperative adjuvant chemoendocrine therapy must be performed for patients with node-negative breast cancer with more than two poor prognostic pathological factors.

Adult↗
PubMed1996

[Successful treatment of pulmonary alveolar proteinosis by massive bronchoalveolar lavage].

In two patients with pulmonary alveolar proteinosis, PaO2 was normalized by massive bronchoalveolar lavage (BAL). Patient 1: A 29-year-old man presented with exertional dyspnea and a PaO2 of 57.8 mmHg. After four BALs, the PaO2 was 106.4 mmHg. For ten years thereafter he has been doing well. Patient 2: A 58-year-old women presented with extertional dyspnea and a PaO2 of 64.4 mmHg. The PaO2 increased to 110.6 mmHg after four BALs. BAL required much skill, but it is one of the most effective methods for the treatment of pulmonary alveolar proteinosis. Because this condition is related to an interstitial process, these two patients need to be followed carefully.

Adult↗
PubMed1996

[A case of acute occlusion of left middle cerebral artery due to an embolus treated successfully with percutaneous transluminal angioplasty].

The acute occlusion of cerebral artery by embolism causes severe cerebral infarction. In cases with poor colateral circulation, cerebral infarction develops more severely. In these cases, quick recanalization of the occluded cerebral artery is necessary to prevent severe hemorrhagic infarction and brain edema. We report a case where interventional techniques were used to bring about quick recanalization of occluded cerebral artery. We encountered a case of a sixty-year-old male who experienced complete occlusion of the left middle cerebral artery due to an embolus. It was very hard to pass a guide wire through the embolic lesion. At first, we tried mild local fibrinolysis therapy using tissue plasminogen activator, but we could not get any recanalization. However, after mild local fibrinolysis therapy, the guide wire could be passed through the occlusion point. Secondly, we tried percutaneous transluminal angioplasty (PTA) with 2.0mm diameter angioplastic balloon using up to five atomic pressures, after which we obtained partial recanalization. Finally we achieved total recanalization of the middle cerebral artery by PTA with a 2.5mm diameter angioplastic balloon. We crushed this embolus using the angioplastic balloon with up to six atomic pressures. The point of the techniques is to press the embolus against the arterial wall. After this angioplasty, there was an occlusion of the common trunk of the posterior parietal artery and the angular artery. However there was neither massive hemorrhagic infarction nor massive brain edema on follow up CT. In the treatment of acute occlusion of the cerebral artery due to embolism, we found PTA is very effective against the embolus. In the future, we need to develop a retrieving device and a balloon that will prevent the production of small emboli during the crush process involved when bringing about recanalization using PTA.

Acute Disease↗
PubMed1995

Effects of local anaesthesia on formalin-induced Fos expression in the rat dorsal horn.

A subcutaneous injection of formalin into foot pad of the rat produces a bimodal nociceptive response including an early intense response in the first 5 min and a later moderate response that is exhibited from 20 to 60 min after injection. In this study, we investigated the effects of blocking the early phase and late phase input, respectively, on Fos-like immunoreactivity (Fos-LI) expression in dorsal horn neurones. Rats of the early phase block (EB) group were injected with 5% formalin (0.05 ml) into the footpad 5 min after a s.c. injection of 4% lidocaine (0.15 ml) into the angle. The rats of the late phase block (LB) group were injected with 5% formalin into the footpad 10 min before the s.c. injection of 3% prilocaine (0.20 ml) containing felypressin into the ankle. The rats of the control group were given the formalin injection alone. Fos-LI was detected in the dorsal horn 2 h after the formalin injection. The numbers of Fos-LI neurones in the dorsal horn of both EB and LB group were markedly decreased compared with the control group, being 31.3% (laminae I-III of EB), 37.1% (laminae I-III of LB), 13.9% (laminae IV-VI of EB) and 16.2% (laminae IV-VI of LB) of the control values. No significant difference was observed between EB and LB group. These findings suggested that the early and late phase contribute in concert to the induction of genetic changes in dorsal horn neurones after formalin injection.

Anesthesia, Local↗
PubMed1995

Enhancement of aromatic amino acid-nucleic acid base stacking interaction by metal coordination to base: fluorescence study on a tryptophan-Pt(II)-guanine ternary complex.

In order to investigate the effect of the Pt(II) ion on the stacking interaction between tryptophan and a guanine base, the quenching of Trp fluorescence was monitored for some systems in the absence and presence of the metal ion, and the association constants were obtained by the analysis of Eadie-Hofstee plots. All spectral data suggested that the stacking interaction is enhanced by the Pt(II) coordination to the guanine N7 atom. The result indicates the importance of the metal ion as a bookmark in the specific recognition of a nucleic acid base by an aromatic amino acid residue.

Base Composition↗
PubMed1995

Morphological classification of retinal ganglion cells in mice.

Mice have been used for extensive studies on optic nerves and retinal ganglion cells, but mouse retinal ganglion cells have not been classified morphologically. In the present study, normally placed retinal ganglion cells and displaced retinal ganglion cells in pigmented and albino mice were classified morphologically using horseradish peroxidase. These cells were classified into three types according to the sizes of the soma and the dendritic field: type I cells, large soma and large dendritic field; type II cells, small-to-medium soma and small dendritic field; and type III cells, small-to-medium soma and large dendritic field. Some ganglion cells had both symmetric and asymmetric cells. Each type was further subdivided according to the termination level of dendrites in the inner plexiform layer and the dendritic branching pattern. Except for type III displaced ganglion cells, dendrites of the normally placed ganglion cells and the displaced ganglion cells ramify in the outer two-fifths of the inner plexiform layer (sublamina a) or the inner three-fifths of the inner plexiform layer (sublamina b). Type III displaced ganglion cells ramify only in sublamina a. Dendrites of some normally placed type I ganglion cells ramify in both sublaminae. Displaced biplexiform cells were observed, the dendrites of which ramify in both the inner and the outer plexiform layers. All cell types were found in both mouse strains.

Animals↗