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Biomedical subjects

Y Fujii

Publications and source records attributed to Y Fujii.

At least 577 records · Page 32Linked to original sources
PubMed1995

Different organization of intermediate filaments in columnar cells of rat large intestinal mucosa as revealed by confocal laser scanning microscopy and quick-freezing and deep-etching method.

The relationship between cell differentiation and ultrastructural changes of intermediate filaments (IF) was studied in columnar cells of large intestinal mucosa of rats by confocal laser scanning microscopy and quick-freezing and deep-etching method. A feature of the IF in immature columnar cells was minibundle formation with prominent branching, which organized the meshwork structures. The minibundles, which appeared to be formed by the attachment of two or more IF in side-to-side fashion, were loosely distributed throughout the cytoplasm. In contrast, in mature columnar cells, the IF were densely distributed under the terminal web in the cytoplasm and beneath the upper part of the lateral membrane regions, whereas the other areas of the cytoplasm contained only a small number of IF. Minibundle formation was not observed, and the branching was rarely identified. The changes in the distribution and density of IF, which are expressed in specific areas of mature columnar cells, apparently represent a characteristic of intracellular differentiation. It is suggested that the dissociation of minibundled IF, which was often observed in the immature columnar cells, is an important step in the acquisition of functional polarity in cells of this type.

Animals↗
PubMed1995

Freeze-fracture immunocytochemistry for intracellular localization of serotonin in mast cells stimulated with compound 48/80.

Changes of intracellular localization of serotonin in rat mast cells were examined by freeze-fracture immunocytochemistry, to prevent the translocation of the serotonin antigen. Rat peritoneal cells including mast cells were stimulated in vitro with compound 48/80, at 17 degrees C for 0, 30 or 60 s for exocytosis to occur. The mast cells were fixed, quickly frozen and freeze-fractured to expose the antigen on the fractured surface. They were immunostained with serotonin antibody, and the immunoreactions on the fractured surface were examined on ultrathin sections by electron microscopy. Unstimulated mast cells exhibited serotonin localization mostly in each intragranular matrix. In contrast, mast cells stimulated for 30 s exhibited increased serotonin in their intergranular cytoplasm. Mast cells showed more distinct immunoreactions in the cytoplasm where degranulation would be promoted after 60 s. It is suggested that intracellular release of serotonin occurred in the stimulated mast cells.

Animals↗
PubMed1995

Effect of balloon angioplasty on high grade symptomatic vasospasm after subarachnoid hemorrhage.

Of 455 cases of ruptured intracranial aneurysm treated with radical surgery from January 1987 to March 1992, 19 cases with high grade symptomatic vasospasm were treated by percutaneous transluminal balloon angioplasty (PTA). The indication for PTA was high grade symptomatic vasospasm which does not respond to conservative medical treatment. Of the 36 segments of vasospastic arteries, severe vasospasm (angiographical constriction more than 50% of diameter on admission) was observed in 67%. PTA dilated these vasospastic arteries significantly (diameter of more than 75% of diameter on admission) in 83%. Follow up angiography revealed neither recurrence of vasospasm nor chronic atherosclerotic changes. Clinical improvement within 24 hours after PTA was observed in 63% of cases (7 of 17 cases with consciousness disturbance, 5 of 16 cases with motor weakness and one of 7 cases with aphasia). Outcomes at the time of discharge were excellent in 10 cases, good in 3, fair in 4, and lethal in 2. SPECT study before and after PTA confirmed improvement of cerebral blood flow in 3 out of 5 cases investigated. PTA for high grade symptomatic vasospasm after subarachnoid hemorrhage is considered an effective treatment method for the patient who does not respond to medical therapy. Immediate improvement of angiographical and clinical findings were frequently observed immediately after PTA. Exact indication and timing of PTA should be postulated after much more cases have been treated with this methal.

Adult↗
PubMed1995

Balloon angioplasty immediately after surgical clipping for symptomatic vasospasm on admission. Report of four cases.

In spite of recent advancements in the management of ruptured aneurysm, there are still controversies as to how to threat the patients in serious conditions, one of these concerning whether to operate patients admitted with symptomatic vasospasm (vasospasm on admission) and when. While early surgery may protect patient from further rupturing, it may also increase risk of worsening by inducing much more vasospasm. Four cases of severe vasospasm associated with aneurysmal subarachnoid hemorrhage (SAH) were reported. All of these cases showed symptomatic and angiographical vasospasm on their admission 3-11 days after initial attack of SAH. All cases had a preoperative clinical grading using Hunt & Kosnik of IV, and were treated by early surgery with clipping followed by percutaneous balloon angioplasty (PTA) immediately after clipping. Two cases returned to their previous occupations, while one case remained bed ridden and one died in spite of therapy. Early surgery in this series actually prevented further rupturing, but it is not clear whether PTA immediately after clipping may prevent further deterioration by progression of vasospasm. For selected cases especially those with reversible ischemia, this combined treatment may offer more favorable results than late surgery with conservative medical care. Further investigation is necessary to support the validity of this therapy.

Adult↗
PubMed1995

Surgical experience with massive lobar haemorrhage caused by cerebral amyloid angiopathy.

Nineteen patients with massive lobar haemorrhage without angiographic lesions received direct or stereotactic surgery, and biopsy specimens were examined histologically. Ten patients (53%) were found to have vessels positive for Congo-red staining, and demonstrating amyloid angiopathy. In the patients with amyloid angiopathy, CT scan and surgical findings were investigated. Subarachnoid haemorrhage (9/10), irregularly shaped haematoma (9/10) and fluid-blood density level in the haematoma cavity (7/10) were frequently found on CT scan. The characteristic surgical findings in patients treated by direct surgery were subarachnoid haemorrhage adjacent to intracerebral haematoma (8/8) and the existence of a tangle of vessels in the haematoma cavity (4/8). Evacuation of haematomas was relatively easy, and difficulty of haemostasis was not encountered during surgery.

Aged↗
PubMed1995

Alpha-fetoprotein-producing gastric carcinoma: biological properties of a cultured cell line.

We describe a gastric carcinoma cell line that has been maintained in vitro for more than 10 years and retains the capacity to produce a large amount of alpha-fetoprotein. This cell line was isolated from a metastatic lymph node of a 63-year-old male patient with advanced gastric carcinoma (T2N3P0H0M0) who showed high serum levels of alpha-fetoprotein. The primary tumor was moderately differentiated tubular adenocarcinoma and the lymph node was poorly differentiated adenocarcinoma without any particular pattern. The cultured cells grew as densely packed islet-like colonies with small polygonal cells. Electron microscopy revealed cells abundant in cytoplasmic organelles, with some cellular attachments being tight with junctional complexes and some being loose across intercellular spaces. The free cell surface had microvilli. The population doubling-time was 152 h at passage 58. Chromosomal analysis revealed the modal number to be 77, with numerous karyotype abnormalities. The tumorigenicity of the cultured cells in athymic nude mice was positive only when they were subcutaneously transplanted beneath a plastic plate, but when the cells were transplanted subcutaneously or administered by intrasplenic injection in intact or weakly irradiated nude mice, no tumorigenicity was shown. The cell line produced tumor-associated antigens, such as alpha-fetoprotein, carcinoembryonic antigen, and tissue polypeptide antigen. This cell line may be useful for comparative studies of different types of gastric carcinoma and alpha-fetoproteins of different origins.

Adenocarcinoma↗
PubMed1995

Circulatory responses to laryngeal mask airway insertion or tracheal intubation in normotensive and hypertensive patients.

The effects of laryngeal mask airway (LMA) insertion and tracheal intubation on circulatory responses were studied in normotensive (n = 24) and hypertensive (n = 22) patients. In a randomized, double-blind manner, LMA insertion or tracheal intubation was performed after induction of anaesthesia with thiopentone and muscle relaxation with succinylcholine. In both normotensive and hypertensive patients, heart rate (HR), mean arterial pressure (MAP) and rate-pressure product increased after tracheal intubation or LMA insertion compared with baseline (P < 0.05). The haemodynamic changes were greater after intubation than after LMA insertion (P < 0.05). Following intubation of the trachea or insertion of the LMA, HR increased more markedly in hypertensive patients than in normotensive patients (P < 0.05). Plasma adrenaline and noradrenaline concentrations after tracheal intubation or LMA insertion increased compared with baseline values (P < 0.05) in normotensive and hypertensive patients. The increase in noradrenaline concentration after tracheal intubation was greater than that after LMA insertion (P < 0.05). No patient revealed ECG evidence of myocardial ischaemia. We conclude that insertion of LMA is associated with less circulatory responses than tracheal intubation in both normotensive and hypertensive patients.

Adult↗
PubMed1995

Amrinone improves contractility of fatigued diaphragm in dogs.

The effects of amrinone, a bipyridine derivative, on diaphragmatic contractility and fatigue were examined in 36 anaesthetized, mechanically ventilated dogs divided into four groups. In Group Ia (n = 8), dogs without diaphragmatic fatigue were given a bolus injection (0.75 mg.kg-1) followed by continuous infusion (10 micrograms.kg-1.min-1) of amrinone iv. In Group Ib (n = 8), animals without fatigue received infusion only of maintenance fluid. In Group IIa (n = 10) and Group IIb (n = 10), diaphragmatic fatigue was induced by intermittent supramaximal bilateral electrophrenic stimulation at a frequency of 20 Hz applied for 30 min. After producing fatigue, amrinone (0.75 mg.kg-1 loading dose plus 10 micrograms.kg-1.min-1 maintenance dose) iv were administered in Group IIa. Only maintenance fluids were administered in Group IIb during this period. Diaphragmatic contractility was assessed in each group by measuring transdiaphragmatic pressure (Pdi). Compared with Group Ib, Pdi at any stimuli in Group Ia did not differ. After producing fatigue, in Group IIa and Group IIb, Pdi decreased at low-frequency (10-30 Hz) stimulation (P < 0.05), whereas no change in Pdi was observed at high-frequency (50-100 Hz) stimulation. In Group IIa, Pdi to each stimulus increased during amrinone infusion compared with Group IIb (p < 0.05). In Group IIb, the speed of recovery from fatigue was relatively slower at low-frequency stimulation. The integrated diaphragmatic electric activity (Edi) did not change throughout the experiment. These results indicate that amrinone improves contractility in the fatigued diaphragm.

Amrinone↗
PubMed1995

Prevention of postoperative nausea and vomiting with granisetron: a randomized, double-blind comparison with droperidol.

The effects of granisetron for preventing postoperative nausea and vomiting were investigated in a randomized, double-blind comparison with droperidol and placebo in 100 patients undergoing general anaesthesia for major gynaecological surgery. The patients received a single dose of either granisetron (40 micrograms x kg(-1), n = 25), droperidol (1.25 mg, n = 25; 2.5 mg n = 25) or placebo (saline, n = 25)iv over two to five minutes immediately before induction of anaesthesia. The antiemetic effects of these drugs were evaluated during the first three and the next 21 hr after recovery from anaesthesia. During 0-3 hr after anaesthesia, the frequency of nausea and vomiting was 60%, 12%, 16% and 12% after administration of placebo, granisetron, droperiodol 1.25 mg or droperidol 2.5 mg, respectively. The corresponding frequencies during 3-24 hr after anaesthesia were 44%, 8%, 36% and 12%. The efficacy of granisetron in preventing postoperative nausea and vomiting was almost equal to that of droperidol 2.5 mg. The awakening time in the patients who had received droperidol 2.5 was prolonged by approximately three minutes compared with the placebo group (P <0.05), and postoperative drowsiness/sedation was observed in these patients. In conclusion, preoperative prophylactic administration of granisetron is superior to that of droperidol in the prevention of postoperative nausea and vomiting after anaesthesia.

Adult↗
PubMed1995

Effects of calcium channel blockers on circulatory response to tracheal intubation in hypertensive patients: nicardipine versus diltiazem.

We studied the circulatory responses to laryngoscopy and tracheal intubation in 37 hypertensive patients who received nicardipine 30 micrograms.kg-1 iv (Group N, n = 12), diltiazem 0.3 mg.kg-1 (Group D, n = 12) or saline placebo (Group C, n = 13) 60 sec before the initiation of laryngoscopy. Anaesthesia was induced with thiopentone 5 mg.kg-1 iv, and succinylcholine 2 mg.kg-1 iv was used to facilitate tracheal intubation after precurarization with vecuronium 0.02 mg.kg-1 iv. In patients in Group C heart rate (HR) increased from 79 +/- 14 (baseline) to 110 +/- 12 (P < 0.05) associated with tracheal intubation; mean arterial pressure (MAP) increased from 116 +/- 8 to 140 +/- 77 (P < 0.05) and rate-pressure product (RPP) increased from 13385 +/- 2393 to 21251 +/- 3883 (P < 0.05). The changes from baseline values in HR and RPP after tracheal intubation in Group D were less than those in Groups C and N (P < 0.05). The increase in MAP following tracheal intubation in Groups N and D was lower than that in Group C (P < 0.05). We conclude that, compared with nicardipine, administration of diltiazem iv is associated with less circulatory response to tracheal intubation in hypertensive patients.

Adult↗
PubMed1995

Post-tetanic burst count: a stimulating pattern for profound neuromuscular blockade.

The purpose of this study was to compare the pattern of recovery from vecuronium 0.07 mg.kg-1 induced neuromuscular blockade using post-tetanic burst count (PTBC)-(three short tetanic bursts of 0.2 msec duration every 20 msec given every second following a tetanus), and post-tetanic count (PTC)-(0.2 msec single twitch stimuli given every second following a tetanus) using an accelerometer in 60 adult patients during nitrous oxide-oxygen-isoflurane anaesthesia. In addition, the relationship among PTBC, PTC, and T1 (the 1st response in the train-of-four (TOF) stimulation) was examined to investigate whether the PTBC had an advantage over the PTC or TOF for evaluating intense neuromuscular blockade. The PTBC was greater than PTC during the 15-35 min after the administration of vecuronium (unpaired t test with Bonferroni's correction, P < 0.05). Time to the return of PTB response was shorter than that of PTT (17.7 +/- 3.2 vs 22.7 +/- 3.7 min, unpaired t test, P = 0.0005). Time from the return of PTB to that of T1 was longer than the time from the return of PTC to that of T1 (13.3 +/- 2.6 vs 9.2 +/- 2.8 min, unpaired t test, P = 0.0003). At the return of T1, PTBC was greater than PTC (14.3 +/- 6.9 vs 9.4 +/- 2.3, unpaired t test, P = 0.0153). These results suggest that, using PTBC, a more profound level of neuromuscular blockade can be evaluated than that using PTC.

Adult↗
PubMed1995

Granisetron-dexamethasone combination reduces postoperative nausea and vomiting.

The prophylactic antiemetic efficacy of combined granisetron and dexamethasone was evaluated in a randomized double-blind manner in 88 patients undergoing general anaesthesia for major gynaecological surgery. Immediately after recovery from anaesthesia, patients received a single dose of either placebo (saline, n = 22), granisetron (20 micrograms.kg-1, n = 22), dexamethasone (8 mg, n = 22) or combined granisetron and dexamethasone (20 micrograms.kg-1 and 8 mg, respectively, n = 22) iv. The treatment groups were similar for patient demography, surgical procedures, anaesthetics administered and opioids given. Postoperatively, the frequency of nausea was 32%, 23%, 27% and 5% after administration of placebo, granisetron, dexamethasone and granisetron plus dexamethasone, respectively; the corresponding frequencies of vomiting were 23%, 23%, 23% and 5%. The incidence of adverse events postoperatively were not different among the groups. It is concluded that prophylactic administration of combined granisetron and dexamethasone is effective in preventing postoperative nausea and vomiting after anaesthesia.

Adult↗
PubMed1995

Percutaneous transluminal angioplasty in a canine model of cerebral vasospasm: angiographic, histologic, and pharmacologic evaluation.

BACKGROUND: Cerebral vasospasm following subarachnoid hemorrhage (SAH) is one of the leading factors that deteriorate the clinical outcome after aneurysmal surgery. Percutaneous transluminal angioplasty (PTA) is a method to directly dilate the constricted vessel using the intravascular neurosurgical technique. METHODS: Angiographic, histologic, and pharmacologic evaluations related to PTA are presented, using a canine double-injection model of SAH. In angiographic evaluation, we studied the effect of PTA performed on day 1, 4, or 7 of SAH. We performed sequential histologic study by light microscopy using the same for the angiographic evaluation. In pharmacologic evaluation, we measured in vitro isotonic constrictive force using two vasoconstrictors immediately after PTA on normal basilar arteries (control group) and basilar arteries on day 7 of SAH. RESULTS: In angiographic evaluation, we observed the effective dilation of spastic artery immediately after PTA and saw no recurrence of vessel constriction when PTA was performed on day 7 of SAH. However, the preventive effect of PTA was inconsistent when it was performed earlier after SAH (days 1, 4). In histologic evaluation, PTA segments immediately after PTA showed denuding of endothelial cells and stretching of the internal elastic lamina without disruption of the muscle layer. In pharmacologic evaluation, there was no difference in isotonic constrictive force created by vasoconstrictors between the PTA and non-PTA segments without SAH. However, there was a statistically significant reduction of isotonic constrictive force on the PTA segment with SAH. CONCLUSIONS: We suggest that the mechanism of PTA vasodilation in vasospasm after SAH may result from mild functional changes in the vascular wall when PTA was applied on day 7 of SAH. The functional changes would not be adequately induced to prevent recurrence of vasoconstriction when PTA was applied soon after SAH.

Angioplasty↗
PubMed1995

A survey on surgeons' attitudes and practices in the care of HIV-infected patients in Japan.

We conducted a survey to learn surgeons' attitudes and practices concerning HIV-infected patients in Japan. We mailed questionnaires to 174 general hospitals and received responses from 126 (72.6%). Concerning preoperative HIV testing, 41% of the hospitals had never performed it. Twenty-nine percent had operated on at least one HIV-infected patient and 144 HIV-infected patients have received surgery under spinal, epidural or general anesthesia. During surgery, 6 accidental needlesticks occurred, but fortunately no seroconversion has been reported since the accidents. Therefore widerspread use of barrier precautions should be undertaken during surgical intervention. This survey revealed that 40-60% of the hospitals coped inadequately with such surgery. Therefore it is important to arrange a system in Japan so that HIV-infected patients will be able to receive necessary surgical treatment. For that purpose, a medical educational program for health care professionals is needed, because not only surgeons but all health care professionals in hospitals should be able to take part in the treatment of HIV-infected patients.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Effects of ACTH on brain midline structures in infants with infantile spasms.

Changes of the midline structures of the brain, including the pons, cerebellar vermis, and corpus callosum, induced by adrenocorticotropic hormone (ACTH) therapy in 7 infants with infantile spasms were investigated using magnetic resonance imaging. Decreased volume of these parts of the brain was induced in almost all infants. Decreased volume of the pons was thought to be closely related to sleep disturbance during ACTH therapy. These results may demonstrate that the cessation of convulsive episodes in infants with infantile spasms treated with ACTH is due to its direct action on the brainstem.

Adrenocorticotropic Hormone↗
PubMed1995

Ice-based altitude distribution of natural radiation annual exposure rate in the Antarctica zone over the latitude range 69 degrees S-77 degrees S using a pair-filter thermoluminescence method.

Both ice-based altitude distributions of natural ionizing radiation exposure and the quasi-effective energy of natural radiation over Antartica over the latitude range 69 degrees S - 77 degrees S during approx. 500 days were measured using thermoluminescent dosimeters. The results shows that dependence on altitude above sea level of the exposure rate increases by almost three-fold with each increase of 2000 m of altitude, thus deviating from the general rule stating that the exposure rate should double with each 2000 m. Although the exposure rate shows a dependence on altitude, altitude dependence of the quasi-effective energy of natural radiation over Antartica is not observed. In the present study it is observed that natural radiation occurring over the ice base of Antartica consists mainly of cosmic rays.

Altitude↗