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Biomedical subjects

K Nishihara

Publications and source records attributed to K Nishihara.

At least 73 records · Page 4Linked to original sources
PubMed1996

Echo-Doppler evaluation of reverse flow sign in the intrahepatic portal branches after surgery.

OBJECTIVE: The author's evaluated the clinical significance of the development of reversed portal flow after abdominal surgery other than portosystemic shunt procedure. SUMMARY BACKGROUND DATA: There have been several reports in regard to reversed portal flow demonstrated by pulsed Doppler ultrasonography, most of which were related to portal hypertension. To the authors' knowledge, this is the first report in which reversed portal flow also is present in patients who have undergone abdominal surgery other than portosystemic shunt procedure. METHODS: Preoperative and postoperative pulsed Doppler ultrasonographic examinations were performed in 126 patients who underwent abdominal surgery. Postoperatively, the portal flow direction was assessed in the right portal branch or the umbilical portion of the left portal branch. RESULTS: Of the 126 patients, reversed portal flow developed in 10 after surgery; 9 of them died of liver failure. CONCLUSIONS: The postoperative development of reversed portal flow is considered to have grave prognostic significance, indicating that the degree of postoperative liver damage is extremely critical.

Adult↗
PubMed1996

The differences of self-ratings of sleep quality associated with epinephrine and wake time during 4 hour sleep.

The present study examined the differences of self-ratings of 4 h sleep in three states: L-WE, where the percentage of waking time and urinary epinephrine are low (< 20% waking time); H-W, where the percentage of waking time and epinephrine levels increase along the basal regression line as determined by a previous study (20-100% waking time and < 7 ng/min); H-E, where epinephrine levels increase more than expected from the basal regression line for the two parameters (> 7 ng/min). Eight healthy male subjects participated twice in a 4 h polysomnograph experiment with four types of sleep onset (total of 64 observations). In group L-WE (52 observations for eight subjects), there were no excessively negative feelings on sleep latency, sleep depth, and feelings of sleep compared with usual sleep according to the questionnaire. Subjective sleep diagrams in group L-WE were similar to polysomnographic findings. Thus, group L-WE was thought objectively and subjectively to have a good sleep state. Groups H-W (eight observations for four subjects) and H-E (four observations for two subjects) had negative feelings regarding sleep depth and feelings of sleep compared with usual sleep. Approximately half the group H-W underrated their sleep compared with objective diagrams, while all cases in group H-E remarkably underrated their sleep in the subjective diagrams. The state of remarkable adrenal medullary secretory activity seen in group H-E and that of the slightly increased activity shown in group H-W were included in poor sleep states objectively and subjectively.

Adrenal Medulla↗
PubMed1996

Lack of effect of vancomycin and gentamicin on auditory function in guinea pigs.

The dispositions of vancomycin (VCM) and gentamicin (GM) in plasma and perilymph after single and multiple administrations and the effects of multiple administrations of VCM or GM alone and the combination of both drugs on auditory function were studied in male guinea pigs. The pharmacokinetic parameters of VCM and GM obtained from plasma drug concentration-time data after single and multiple (22 days) intramuscular administrations of VCM (200 mg/kg of body weight) alone and GM (50 mg/kg) alone were not significantly different from those after combined administration of VCM (200 mg/kg) and GM (50 mg/kg). There was no change in the penetration ratio of VCM and GM into perilymph between administration of VCM or GM alone and the combination of both drugs. Furthermore, the hearing threshold of guinea pigs was not affected by VCM or GM alone or the combination of both drugs within the range of therapeutic VCM and GM levels in plasma in humans.

Animals↗
PubMed1996

Cervical osteoplastic laminotomy using autogenous bone.

Cervical foraminotomies are performed from the fifth to the eighth cervical nerve roots on both sides. On the side with more marked radiculopathies the laminae are osteotomized to the full extent, but not so completely on the other side. The mass of laminae from C-3 to C-7 is lifted up using the incompletely severed side of the laminae as the fulcrum. The removed spinous processes of C-6 and C-7 are adjusted and fixed between the articular joints and the lifted laminae from C-4 to C-6. This procedure prevents extradural scar formation, there are no complications caused by foreign bodies, postoperative neuroimaging is possible because no metallic artifact is formed, and extensive decompression is achieved for the cervical cord and nerve roots.

Adult↗
PubMed1996

[Relationships between wakefulness of mothers and their infants' movements during night sleep of postpartum 6 weeks].

Relationships between wakefulness of mothers and their infants' movements during night sleep in postpartum period were studied under conditions in daily life. Subjects were ten primiparae, aged 23-31 yrs (mean age, 26.8 yrs), who had a normal course of pregnancy and delivery. Eight of their infants were breast-fed, and two were formula-fed. Mother's polysomnograms, (EEG, EOG, EMG, and ECG) and actigrams of infants' legs were simultaneously recorded using Medilog 9000 at home in the 1st, 3rd and 6th postpartum weeks. Mothers' sleep stages and their infants' movements were visually scored by an epoch of one minute. The infants' movements were classified into four states, MOV0, MOV1, MOV2, and MOV3. We defined MOV0 as no activities during one epoch, MOV1 as less than 20 seconds activities, MOV2 as from 20 to 40 seconds activities and MOV3 as from 40 to 60 seconds activities. The average times of wakefulness on the mothers were 102.6 min (SD = 23.5), 84.8 min (SD = 52.8) and 79.4 min (SD = 40.5) for 1st, 3rd and 6th postpartum weeks, respectively. There were no significant differences among them. The mothers' wakefulness coincided with the infants' movements MOV3 was 86.9% for total epochs of MOV3, while deep sleep of the mothers was observed during epochs of MOV0 and MOV1. This trend did not change across the postpartum weeks. The time-lag between the mothers' wakefulness and their infants' movements was calculated. In 85.4% of 48 times of mother's awakenings for feeding their infants, their infants began to move before their mothers woke up. In 63.4% of the cases, the mothers woke up within two minutes after their infants began to move. In the present study, eight of the ten mothers satisfactorily adapted themselves to the life style in the postpartum period, while two had difficulties in adaptation. In conclusion, ten mothers' wakefulness during night sleep in postpartum period was related to their infants' movements, and its relationship did not change through the 1st, 3rd and 6th weeks of delivery.

Adaptation, Psychological↗
PubMed1995

Event-related changes of background electroencephalogram during contingent negative variation paradigm.

The autoregressive model was applied to the background electroencephalogram during the tone(S1)-tone(S2)-respond contingent negative variation paradigm under eyes-open condition. The EEG data were obtained at the scalp sites of Fz, Cz, and Pz in seven normal males. During the first half of the interstimulus interval (ISI) of 2.5 s, Fz-dominant excitatory process was suggested in concordance with an orienting response to stimulus 1. In the second half of the ISI, Pz-dominant inhibitory process was considered. The stimulus 2 presentation and the required motor response promoted the Pz-dominant process.

Adult↗
PubMed1995

Adenosquamous carcinoma of the gall-bladder with gastric foveolar-type epithelium.

An 80 year old Japanese man had adenosquamous carcinoma of the gall-bladder characterized by an adenocarcinoma (AC) in the gall-bladder lumen and a squamous cell carcinoma (SCC) in the invaded region of the liver. In the AC, the tumor cells consisted of atypical columnar epithelium with pseudostratification, mimicking gastric foveolar epithelium, while atypical signet-ring cells were scattered within the SCC. There was an abrupt transition between the AC and SCC areas. The tumor cells in the AC area were intensely positive for galactose oxidase-Schiff staining, and paradoxical concanavalin A staining revealed these tumor cells to have Class II mucins. Immunohistochemically, the tumor cells in foveolar-type adenocarcinoma were diffusely positive for cathepsin D. Flow cytometrical analysis of DNA content showed the AC area to be diploid and the SCC area to be aneuploid. The S-phase fraction of the SCC area (46.9%) was larger than that of the AC area (19.5%). The positive rate of immunostaining for proliferating cell nuclear antigen in the SCC area (mean 50.627%) was larger than that of the AC area (mean 3.048%, P < 0.01). These results suggest that the AC area of this tumor, histochemically and immunohistochemically, showed gastric foveolar-type characteristics, the SCC component was squamous cell metaplasia of the pre-existing AC, and that the SCC area had a greater proliferating capacity than the AC area.

Aged↗
PubMed1995

[Enzyme immunoassay of drug in blood (serum)].

Antiepileptic drugs, cardiac glycosides (digoxin, etc.), theophylline, antiarrhythmic agents (quinidine, procainamide, lidocaine, etc.) and aminoglycosides have narrow therapeutic range and large interindividual variations have been reported for their pharmacokinetics. Therefore, to obtain the appropriate therapeutic effects without undesirable effects, monitorings of above drug concentrations are useful (therapeutic drug monitoring). There are many assay methods (high-performance liquid chromatography, immunoassay, enzyme immunoassay, etc.) to determine drugs in serum. In those assays various enzyme immunoassays, enzyme-multiplied immunoassay technique (EMIT), enzyme-linked immunosorbent assay (ELISA), apoenzyme reactivation immunoassay (ARIS), radial partition immunoassay (RPIA), etc., are developed and widely used in many clinical laboratories. These assay systems offer convenience and great rapidity of assay and satisfactory accuracy and reproducibility but lack a little specificity of antibody.

Drug Monitoring↗
PubMed1995

Increased in vitro and in vivo tumoricidal activity of a macrophage cell line genetically engineered to express IFN-gamma, IL-4, IL-6, or TNF-alpha.

Genetically engineered monocytes and macrophages may have potential as effector cells for the adoptive immunotherapy of cancer. As a first step, we have transfected the genes encoding either mouse interferon (IFN)-gamma, human interleukin (IL)-6, mouse IL-4, or mouse tumor necrosis factor (TNF)-alpha into the mouse macrophage cell line, J774A.1 cells using retroviral vectors. In vitro activation of J774A.1 cells by gene modification was assessed by morphological changes, proliferative activity was determined by [3H]-TdR uptake, and cytolytic activity was assessed using an 18-hour chromium-51 (51Cr) release assay. In vivo tumoricidal activity was studied by means of local adoptive immunotherapy using intratumoral injection of transfected effector cells. IFN-gamma gene-transfected J774A.1 [J7(IFN-gamma)] cells developed filamentous processes, increased doubling times, and enhanced tumoricidal activity against three tumor cell lines: the TNF-sensitive fibrosarcoma line WEHI 164 and the TNF-alpha-resistant cell lines B16 melanoma and C1300 neuroblastoma. IL-6-, TNF-alpha-, and IL-4-gene-transfected J774A.1 cells also had augmented tumoricidal activity but did not display any changes in morphology or growth. Cytolytic activity was markedly reduced after the addition of anti-TNF-alpha antibodies. Cytolytic J7(IFN-gamma) cells showed upregulated expression of TNF-alpha messenger RNA. After intratumoral injection of J7(IL-4) and J7(IFN-gamma) cell mixtures, 50% of established B16 melanomas were rejected by C57BL/6 mice, thereby demonstrating synergistic killing. Further studies on gene-transfected macrophages should better define their potential usefulness in tumor immunotherapy.

3T3 Cells↗
PubMed1995

[A case report of a metaplastic carcinoma of the breast diagnosed by the preoperative needle biopsy].

A case of the metaplastic carcinoma, a rare type of the breast cancer, was reported. A 49-year-old woman noticed the left breast lump. Ultrasonography revealed a well circumscribed hypoechoic mass measuring 3 cm in diameter. The preoperative needle biopsy showed the invasive carcinoma with chondrometaplasia. The modified radical mastectomy along with the lymph node dissection was performed. There have been few reports of the metaplastic breast carcinoma diagnosed preoperatively.

Biopsy, Needle↗
PubMed1995

[Procainamide].

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Anti-Arrhythmia Agents↗
PubMed1995

[Theophylline].

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Adolescent↗
PubMed1994

Biomechanical studies on shape effect of hydroxyapatite artificial root upon surrounding jawbone.

To study the shape effect upon surrounding tissue of artificial dental root made of synthetic hydroxyapatite, this paper deals with the numerical analysis of the artificial root on functioning jawbone with the aid of the finite element method (FEM). The stress distribution around artificial roots in the shape of a cylinder, a cone, and three types of corrugated cone, including the newly tailored type implanted in the mandibular molar region, was analyzed in the plane strain state. The numerical results showed that the stress distribution was sensitive to the artificial root shape, and that the stress state was distributed in mitigatory way around the roots of the newly tailored form. The pattern of osteogenesis in the animal experiment and the finite element analysis (FEA) pattern showed a close correlation. Osteogenesis was assumed to occur in the weak or moderate stress distribution zone. The principal stress trajectory pattern in the lamina dura around the tailored artificial root was indicated as being either parallel or normal to the root surface. From this study, the biomechanical property of the tooth can be identified as a vehicle of mastication forces which disperse stresses moderately and equally upon surrounding tissues. Also, the periodontal ligament can be identified as a converting system of principal stress trajectories.

Animals↗
PubMed1994

Adenosquamous carcinoma of the gallbladder: a clinicopathological, immunohistochemical and flow-cytometric study of twenty cases.

Twenty patients (7.4%) with adenosquamous carcinoma of the gallbladder were selected from 271 surgically resected gallbladder cancers. The 20 patients were composed of 8 men and 12 women with a mean age of 66.9 years. Histologically, all twenty tumors showed an abrupt transition between the adenocarcinoma (AC) and squamous cell carcinoma (SCC) areas, and well differentiated AC was also found in the peripheral area of the tumor. A histochemical and immunohistochemical study using alcian blue, periodic acid-Schiff, cytokeratins, involculin and tissue polypeptide antigen disclosed a different nature of the two components. DNA heterogeneity between the components was detected in 5 of 7 cases by flow cytometry. The positive rate of immunostaining for proliferating cell nuclear antigen in the SCC areas (mean 20.55%) was larger than that of the AC areas (mean 11.40%) (P = 0.0029), which indicated that the SCC areas had a greater proliferative capacity than AC areas. These results suggest that the SCC component of adenosquamous carcinoma of the gallbladder arose by a stepwise molecular progression of the pre-existing AC. Furthermore, the prognosis of adenosquamous carcinomas of the gallbladder (mean survival: 10 months) in the advanced stage (pTNM 2-4) was less favorable than those of papillary and well differentiated AC (mean survival: 99 months and 86 months) (P < 0.0001).

Adenocarcinoma↗
PubMed1994

Three synchronous carcinomas of the papilla of Vater, common bile duct and pancreas.

Multiple carcinomas of the pancreatico-biliary tree are rare. A 53 year old Japanese man was diagnosed as having an adenocarcinoma in the papilla of Vater. During the operation, he was also found to have a polypoid mass in the common bile duct. While cutting the operative specimen into stepwise sections, a small tumor was also detected incidentally in the main pancreatic duct of the pancreatic head. Histologically, all three tumors proved to be papillary adenocarcinomas and were restricted to the mucosa. Immunohistochemically, all three tumors were positive for carcinoembryonic antigen, carbohydrate antigen 19-9, chromogranin A and serotonin, while they were negative for somatostatin. Immunoreactivity to the tumor suppressor gene p53 protein (PAb 1801) was found in all three tumors. A flow cytometric analysis of the cellular DNA content revealed all three tumors to be aneuploid. The above results suggested that these three tumors from different sites all had the same histological, immunohistochemical and flow cytometrical characteristics.

Adenocarcinoma, Papillary↗