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Biomedical subjects

H Furuya

Publications and source records attributed to H Furuya.

At least 181 records · Page 10Linked to original sources
PubMed1993

Effects of flumazenil during administration of midazolam on pial vessel diameter and regional cerebral blood flow in cats.

We implanted closed cranial windows in ten cats in order to observe the response of pial vessel diameter by microscopy using fluorescein isothiocyanate-labeled dextran and regional cerebral blood flow (rCBF) by laser Doppler flowmetry during administration of midazolam and reversal with flumazenil. Midazolam was given at 0.8 mg.kg-1 x min-1 for 10 min and maintained at 0.04 mg.kg-1 x min-1 for 50 min (total 10 mg.kg-1). The diameter of arterioles and venules and rCBF showed no significant change. During the last 10 min of midazolam administration, flumazenil, given at 0.1 mg.kg-1 x min-1 for 10 min (total 1 mg.kg-1), caused an increase of MAP and rCBF (P < 0.01) at 5 min after infusion and diameter of larger arterioles (> 50 microns) and venules (50-100 microns) were dilated (P < 0.05). These results indicate that midazolam does not affect the diameter of cerebral arterioles and venules; however, the reversal effects of flumazenil against midazolam are transient vasodilation of larger arterioles accompanied by an elevation of MAP, and an increase in CBF.

Animals↗
PubMed1993

Evidence for basolateral membrane Ca2+/H+ exchange in outer medullary collecting duct.

The relationship between Ca2+ and intracellular pH (pHi) was studied in the rabbit collecting duct from the inner stripe of the outer medulla (OMCDi). When bath Ca2+ was lowered [1 mM Ca2+ plus 2 mM ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA)] intracellular Ca2+ concentration ([Ca2+]i) decreased by 38.3 +/- 6.2% from 265 +/- 25 to 165 +/- 25 nm (n = 4). Lowering bath Ca2+ produced a biphasic response in pHi, transient acidification (from 6.93 +/- 0.06 to 6.80 +/- 0.06) followed by a return of pHi to levels slightly higher than control (pHi = 6.97 +/- 0.06). The acidification was not blocked by bath amiloride or 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) or lumen N-ethylmaleimide (NEM). However, bath amiloride significantly reduced the initial rate of pHi recovery after acidification (0.70 pH U/min in control vs. 0.39 pH U/min with amiloride). Lanthanum, a Ca2+ pump inhibitor, completely inhibited the acidification. Moreover, lowering bath temperature to 20 degrees C also inhibited the acidification. Acidification was blocked when the bath pH was raised to 8.0, whereas lowering bath Ca2+ markedly acidified cells when bath pH was lowered to 6.0 (delta pHi = 0.28 +/- 0.01). We also measured the transepithelial (Vt) and basolateral (Vbl) membrane voltages. Lowering bath Ca2+ depolarized Vt and Vbl by 12.7 +/- 4.9 and 6.0 +/- 2.0 mV, respectively. In summary, 1) lowering bath Ca2+ caused a biphasic response in pHi of OMCDi cells, and 2) the acidification phase is due to H+ influx associated with the Ca2+ pump.

Animals↗
PubMed1993

[A case of radiculitis induced by spinal cord electrical stimulation by a percutaneously inserted needle].

Spinal cord electrical stimulation was performed by a percutaneously inserted needle for causalgia of the right upper limb. The end of electrode was positioned along a line extending down the 5th vertebral body in the vicinity of the right 6th cervical nerve root, after which it was permanently implanted following confirmation of desensitizing effects. Although the patient later returned to normal life without requiring any ancillary medication, beginning after a period of roughly six months, the pain suddenly began to increase when stimulated. When stimulated by extracting the electrode 1 cm under fluoroscopic guide, the irritation was relieved somewhat. As radiculitis of 6th cervical nerve was suspected, selective radicular block of 6th cervical nerve was performed. After selective radicular block, the patient's complaint diminished. Based on the above findings, we consider that the physical stimulation caused by the electrode in contact with the nerve root brought about inflammation of the 6th cervical nerve root. This patient was then treated by removing the causative stimulation and selective radicular block of affected nerve, the details of which are reported.

Electric Stimulation Therapy↗
PubMed1993

[Removal of a bronchial foreign body in a child using the laryngeal mask].

The laryngeal mask (LM) was employed for the removal of a bronchial foreign body (screw) in a 2-year-old boy weighing 16 kg since the 6.0 mm external diameter fiberoptic bronchoscope (FBS) for extraction forceps could not be used under tracheal intubation. Anesthesia was induced with sevoflurane in 100% oxygen. After injection of fentanyl 25 micrograms and vecuronium 2 mg, a gastric tube and a size 2 LM were inserted. Throughout the extraction procedure by the FBS in the left main bronchus, the boy had one lung ventilated manually. The airway pressure was kept under 15 cmH2O to avoid gas leakage around the cuff and gastric inflation. Oxygen saturation of 100% with pulse oximetry and PETCO2 of 35 to 45 mmHg with capnometry were maintained. The foreign body was extracted by biopsy forceps. A Fogarty catheter was not effective because the balloon tip was broken by the screw. The LM does not prevent regurgitation and does not provide adequate ventilation under increased airway pressure, but it facilitates the use of a larger size FBS equipped with a variety of extraction forceps. Therefore, it seems to be a useful device for the removal of bronchial foreign bodies in children.

Bronchi↗
PubMed1992

[A case of type 1 diabetes mellitus with hypothalamic amenorrhea: successful pregnancy following subcutaneous pulsatile administration of LHRH].

A 27-year-old woman with type 1 diabetes mellitus was admitted to the Shimane Medical University Hospital because of secondary amenorrhea. She had been treated with insulin since July, 1986. Fasting plasma glucose and HbA1c levels were controlled within normal limits. However, body weight gradually decreased and amenorrhea started in 1988. Physical examination revealed emaciation with BMI of 17.3. Basal levels of plasma T3, somatomedin C, LH, FSH and estradiol levels were low, whereas HGH levels were slightly elevated. Plasma LH markedly increased in response to LHRH administration. She was diagnosed as having weight loss-related hypothalamic amenorrhea. Induction of ovulation was not obtained with clomiphene citrate. Treatment with subcutaneous pulsatile administration of LHRH (20 micrograms every 120 min) resulted in an increase in plasma levels of LH, FSH and estradiol, which was accompanied by ovulation and corpus luteum formation. Further treatment with pulsatile LHRH administration was followed by conception. Two gestational sacs were detected by ultrasonography. One of them was absorbed at the early stage of pregnancy. She was delivered of one healthy female infant without complications. These findings suggest that it is important not only to control plasma glucose levels but to keep the appropriate weight and support the psychological aspects of the subject in the treatment of diabetes mellitus. Subcutaneous pulsatile LHRH therapy may be effective for the induction of ovulation in clomiphene-resistant hypothalamic amenorrhea; however, it will be necessary to solve the problem of dosage and the interval of LHRH administration in the future.

Adult↗
PubMed1992

Isoflurane in the management of status epilepticus after surgery for lesion around the motor area.

When conventional treatment for status epilepticus fails, general anaesthesia is recommended. We present our experience with isoflurane, an inhalational anaesthetic, in the management of four patients with status epilepticus which occurred soon after surgery for motor area lesion. The seizures were controlled with relatively small concentrations of isoflurane. Hypotension, the only adverse effect of isoflurane, was managed easily with the use of dopamine in physiological saline. Although status epilepticus occurring soon after surgery is transient, it carries a risk of persistent brain damage if active treatment is not instituted promptly. Isoflurane general anaesthesia may be recommended to control it in the intensive neurosurgical care.

Adult↗
PubMed1992

Pharmacokinetics of carteolol in patients with impaired renal function.

In order to determine the appropriate dosage of carteolol in renal dysfunction, the pharmacokinetics of carteolol has been examined in appropriate patients. The plasma concentrations and urinary excretion of carteolol were investigated in 15 patients with varying degrees of renal impairment during the administration of 5-20 mg carteolol hydrochloride (5 mg/tablet) for 2-45 months. Plasma carteolol levels were linearly correlated with the serum creatinine concentration (r = 0.87) and reciprocally with the creatinine clearance (r = 0.82). The urinary carteolol concentration was correlated with the urinary creatinine concentration (r = 0.69) and the urinary carteolol excretion was also correlated with the creatinine clearance (r = 0.79). These relationships become even closer when the plasma carteolol concentrations and urinary excretion rate of carteolol were factored by the administered tablets. The fractional renal excretion of carteolol was virtually constant at various degrees of renal function, and it always exceeded 100%, which indicates that carteolol was actively secreted, even in patients with renal failure. The estimated tubular secretion rate of carteolol was logarithmically correlated with the fractional renal excretion of carteolol (r = 0.93). The results indicate that the dose of carteolol should be determined according to the degree of renal impairment.

Adult↗
PubMed1992

Effect of insulin on potassium secretion in rabbit cortical collecting ducts.

Insulin is known to play an important role in the regulation of extrarenal K homeostasis. Previous clearance studies have shown that insulin decreases urinary K excretion, but the responsible nephron segments have not been identified. In this microperfusion study, in vitro, the effect of insulin on K transport in the cortical collecting duct (CCD), which is thought to be an important segment for regulation of the final urinary K excretion, was investigated. Basolateral insulin (10(-6) M) significantly inhibited net K secretion by 20% (mean JK = -26.2 +/- 4.2 peq.mm-1.min-1 for controls compared with -21.1 +/- 3.4 with insulin, P less than 0.001) and depolarized the transepithelial voltage (VT, from -14.6 +/- 3.5 to -10.8 +/- 3.5 mV, P less than 0.005), recovery did not occur over 60 min. Insulin (10(-11)-10(-5) M) depressed K secretion and depolarized the VT in a concentration-dependent manner. The half-maximal concentration was 5 x 10(-10) M, which is within the physiological range of plasma insulin concentration. In tubules of deoxycorticosterone acetate-treated rabbits, insulin also produced a significant fall in K secretion (from -43.4 +/- 7.5 to -36.1 +/- 5.7 peq.mm-1.min-1, P less than 0.05). Although luminal Ba (2 mM) decreased K secretion (from -14.4 +/- 2.9 to -7.0 +/- 1.7 peq.mm-1.min-1), basolateral insulin (10(-6) M) inhibited K secretion further (to -4.7 +/- 1.3 peq.mm-1.min-1, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Amiloride↗
PubMed1992

Effect of halothane, fentanyl, and ketamine on the threshold for transpulmonary passage of venous air emboli in dogs.

We assumed that the capacity of the lungs to filter gas bubbles would vary as a function of anesthetic management. The effects of halothane (1% inspired concentration [group 1, n = 8]), fentanyl (100 micrograms/kg IV, followed by 1 micrograms.kg-1.min-1 [group 2, n = 7]), and ketamine (10 mg/kg IV, followed by 0.2 mg.kg-1.min-1 [group 3, n = 6]) on the passage of bolus injections of air across the pulmonary circulation were studied in dogs by using transesophageal echocardiography to detect air in the left atrium or the aorta, or both. The thresholds for bolus air detection during halothane, fentanyl, and ketamine administration were 0.05 mL/kg (range 0.01-0.1), 0.5 mL/kg (range 0.2-1.0), and 0.35 mL/kg (range 0.1-0.5), respectively. We conclude that the threshold during fentanyl- or ketamine-induced anesthesia was significantly higher than during halothane-induced anesthesia. Therefore, halothane interferes with the capacity of the lungs to filter air from the pulmonary circulation.

Animals↗
PubMed1992

[Effect of subcutaneous administration of interleukin-1 beta on blood platelet count and serum GM-CSF in patients with myelodysplastic syndrome and aplastic anemia].

Subcutaneous administration of recombinant human Interleukin-1 beta (IL-1 beta) in a dose of 1-3 x 10(4) U/day for 14 to 72 days resulted in an increase in circulating granulocytes and bone marrow monocytes in all the 4 patients examined. Circulating platelet count was also increased in two of four patients with myelodysplastic syndrome (MDS) and aplastic anemia (AA). Bone marrow examination revealed an increase in megakaryocyte count in these patients, whereas the percentage of blast was not changed. An increase in blood platelet count was accompanied by an increase in serum GM-CSF in a patient with AA, whereas serum IL-6 level was not changed throughout the treatment with IL-1 beta. These findings suggest that IL-1 beta may be useful for the treatment of a proportion of patients with MDS and AA who are associated with thrombocytopenia.

Aged↗
PubMed1992

[Effective high frequency jet ventilation setting for the preparation of internal thoracic artery for coronary artery bypass graft surgery].

Effective high frequency jet ventilation (HFJV) setting during the preparation of internal thoracic artery (ITA) was estimated in 35 patients who underwent coronary artery bypass graft (CABG) surgery. During ITA preparation, ventilation with the minimum lung movement without circulatory deterioration is necessary. Therefore, appropriate frequency, inspiratory time interval (Ti%) and working pressure (WP) for HFJV were investigated. Rising WP and prolonged Ti% provoked increasing tidal volume and decreasing PaCO2, whereas the lung extension disturbed the ITA preparation. By modifying the settings of frequency, Ti% and WP, we determined the frequency of 3Hz and Ti% of 50%. The correlation between WP at normocapnia and bodyweight (BW) is expressed in the following formula: WP = 0.16 x BW - 0.0003 (r = 0.72) Moreover satisfactory recording of end-tidal CO2 could not be obtained during HFJV. Therefore, we used transcutaneous CO2 (tc-CO2) analyzer. The coefficient between tc-CO2 and PaCO2 was 0.95, and tc-CO2 was useful as a non-invasive monitoring of PaCO2. There was little change in blood pressure, heart rate and cardiac output during HFJV. However mean pulmonary artery pressure (mPAP) increased significantly during hypercapnia especially when PaCO2 was over 50 mmHg. This suggests that mPAP may be more sensitive to PaCO2 compared with other circulatory parameters. HFJV with these settings produced good outcome for ventilation and circulation during the preparation of ITA.

Adolescent↗
PubMed1992

[Acute myelogenous leukemia transformed from myelodysplastic syndrome with tetraploid chromosome constitution].

A 57-year-old female presented with general fatigue. She had neither lymphadenopathy nor hepatosplenomegaly. Laboratory data revealed anemia and leukopenia (1,500/microliters) with a differential count of 4.5% leukemic cells. The myelogram revealed 34.4% leukemic cells, of which diameter ranged from 20 to 28 microns. The diagnosis was acute myelogenous leukemia (FAB: M2) with myelodysplasia. Cytogenetic analysis revealed that the leukemic cells had chromosome abnormalities involving both diploidy and tetraploidy with structural rearrangement. Structural rearrangement included del(5) (q22q33), del(15) (q22q24), and t(3; 12) (q25;p13). Small dose aclacinomycin-A treatment was effective in reducing the number of leukemic cells in bone marrow, and both anemia and leukocytopenia were improved.

Aclarubicin↗
PubMed1992

[Clinical use of serum erythropoietin determination by the recombigen EPO RIA kit].

Serum erythropoietin (EPO) levels were determined by the recombigen EPO RIA kit (DPC) in normal subjects and patients with renal dysfunction, diabetes mellitus, hypothyroidism and a variety of hematological disorders. Mean (+/- SD) serum EPO levels were 18.6 +/- 5.6 mU/ml in 180 normal subjects and no sex difference was obtained. Serum EPO levels in older subjects were slightly greater than those in younger subjects. There was a negative correlation between serum EPO levels and Ht values in anemic patients with normal renal function, whereas serum EPO levels were within the normal range in anemic patients with renal disorders, suggesting that serum EPO levels were relatively low in patients with chronic renal failure. Serum EPO levels were rather increased in patients with diabetes mellitus and hypothyroidism. High serum EPO levels were obtained in patients with a variety of hematological disorders such as acute leukemia, multiple myeloma, myelodysplasia syndrome, aplastic anemia and pure red cell aplasia. In a patient with pure red cell aplasia treated with glucocorticoids, serum EPO levels were lowered before anemia was recovered and reticulocytes were increased. These findings indicate that measurement of serum EPO levels are useful for not only differential diagnosis of anemia but also clinical evaluation of the treatment.

Adult↗