Biomedical subjects

S Furuta

Publications and source records attributed to S Furuta.

At least 55 records · Page 3Linked to original sources

PubMed1999

Ofloxacin otic solution in patients with otitis media: an analysis of drug concentrations.

OBJECTIVE: To measure the concentration of ofloxacin in otorrhea, serum, and middle ear mucosa after topical administration of 0.3% ofloxacin otic solution. DESIGN: Study of 0.3% ofloxacin otic solution administered in a single dose of 0.5 mL in adults or 0.25 mL in children with chronic suppurative otitis media and perforated tympanic membrane, with serial sampling of otorrhea and serum up to 8 hours after dosing and middle ear mucosa up to 2 hours after dosing. SETTING: Three hospitals in Kagoshima, Japan. PATIENTS: Thirty-eight patients (age range, 3-81 years) with chronic suppurative otitis media and perforated tympanic membrane; 20 patients had sampling of otorrhea and serum and 18 patients (who required middle ear surgery) had middle ear mucosa and serum sampling. RESULTS: High concentrations of ofloxacin were measured in otorrhea samples taken immediately after dosing, followed by a rapid, nonlogarithmic decline. Elimination of the drug through otorrhea was believed to be related to loss from the application site with ear drainage, rather than to biologic mechanisms. Maximum concentration of ofloxacin in otorrhea was seen at the initial sampling time, 30 minutes after dosing, with concentrations measured up to the last sampling at 8 hours. Very low concentrations of ofloxacin were found in serum after topical administration of the drug. Concentrations were not detected in serum samples of most of the patients. The highest concentration measured was 10 ng/mL. Drug concentrations were detected primarily in samples obtained up to 1 hour after the dose was administered. Mucosal drug concentrations were highly variable, ranging from nondetectable to 602 pg/g. For the 6 bacterial strains isolated from the middle ear, the highest minimum inhibitory concentration of ofloxacin was covered by otorrhea drug concentrations measured at up to 8 hours after dosing in some patients. No adverse events were observed. No clinically significant adverse changes in laboratory test results or audiometric results were observed. CONCLUSIONS: Drug concentrations were high in otorrhea, very low or not detected in serum, and highly variable in middle ear mucosa. Nonbiologic loss of the drug with the ear drainage through the external auditory canal and eustachian tube was probably related to the high concentration in otorrhea samples. Drug concentrations in middle ear mucosa suggest that the drug reaches the infection site.

Adolescent↗

PubMed1999

The pathogenesis of dysplastic kidney in a urinary tract obstruction in the female fetal lamb.

BACKGROUND/PURPOSE: The type of renal dysplasia resulting from obstructive uropathy depends on the completeness of the obstruction and its timing with respect to the stage of glomerulogenesis at the time of the obstruction. The authors created a successful obstructive uropathy model in the female fetal lamb to demonstrate the differing pathogenesis of renal dysplasia. METHODS: Female fetal lambs at 60 and 90 days' gestation had their urethra and urachus ligated transabdominally and were delivered by cesarean section at 145 days (full term). Kidney length and cortical thickness were measured, and samples were examined histologically. In the lambs operated on at 90 days, the urine was collected at delivery and Na and CI were measured and compared with the results obtained from normal full-term lambs. RESULTS: Seven of 10 female lambs had hydronephrosis or dysplastic kidneys. The cortext to kidney length ratio was 10+/-3% in the 90-days hydronephrotic group versus 29+/-6% in the controls (P<.001). Morphologically, the 90-day model had dilatation of the collecting tubules with normal glomerular numbers. The 60-day model had tubular cysts with fibromuscular cuffing and reduced glomerular numbers. The fetal urine Na was 47+/-3.3 mmol/L in controls versus 78+/-24 mmol/L in the hydropnephrotic lambs (P<.05). The urine CI in these lambs was 38+/-8.6 mmol/L in controls versus 55+/-14.5 mmol/L in the hydronephrotic lambs (P<.05). CONCLUSIONS: An obstructive uropathy model was created in female fetal lambs. There were no dysplastic changes in the kidneys in lambs operated on at 90 days' gestation, but there were definite dysplastic changes in those operated on at 60 days. Concentrations of Na and CI in the fetal urine are higher than normal in the 90-day model.

Animals↗

PubMed1999

Synovial sarcoma in the parapharyngeal space: case report and review of the literature.

We encountered a rare case of synovial sarcoma in the parapharynx of a 47-year-old Japanese man. This patient presented with an enlarging tumor in the right side of his neck that had grown progressively over a 4-week period. Radiological examinations revealed that the tumor arose from the parapharyngeal space. The tumor could not be completely removed at surgery. Metastasis to the lumbar vertebra was detected postoperatively. The patient underwent three courses of chemotherapy and the delivery of palliative radiation to the lumbar vertebra without success. The patient died of lung metastasis 7 months after surgery.

Combined Modality Therapy↗

PubMed1999

Tissue distribution of polaprezinc in rats determined by the double tracer method.

The tissue distribution of polaprezinc (an insoluble zinc complex of L-carnosine) in rats was studied by the double tracer method using [U-14C-histidine]-, 65Zn-polaprezinc. The 65Zn-radioactivity was measured with an auto-gamma counter, and the 14C containing 65Zn was converted to an absolute count according to the calibration curve for quenching with a liquid scintillation counter with the spill-over method. After the administration of 14C-, 65Zn-polaprezinc to rats, the excretion ratio and time courses in the tissues of the 14C-and 65Zn-radioactivity were different each other. We found that polaprezinc was metabolized as endogenous amino acid or zinc after dissociation in the body. The zinc concentration in plasma reached its maximum at 1 h and decreased slowly, returning to the endogenous level at 11 h after the administration of non-labeled polaprezinc. The concentrations of zinc in liver, kidney, testis, prostate, and cerebrum remained rather constant. The replacement ratios of 65Zn to zinc in the tissues at its maximum percentage were 40% in plasma, 16-20% in liver, kidney, blood, and prostate. The low replacement ratios in testis and cerebrum (2-3%) suggested that zinc uptakes in testis and brain were regulated by the blood-testis-barrier and blood-brain-barrier, respectively.

Administration, Oral↗

PubMed1999

Improved extraction of thinner components from human body fluids by headspace solid-phase microextraction with a Carboxen/polydimethylsiloxane-coated fiber.

An improved method for extraction of thinner components in human whole blood and urine samples by headspace solid-phase microextraction (SPME) with a Carboxen/polydimethylsiloxane-coated fiber is presented. The body fluid samples, containing ethyl acetate, benzene, 1-butanol, toluene, butyl acetate, isoamyl acetate and ethylbenzene as internal standard (IS), were heated at 70 degrees C in a silicone-rubber septum-capped vial in the presence of distilled water plus NaCl; a Carboxen/polydimethylsiloxane-coated SPME fiber was then exposed to the headspace of the vial to allow adsorption of the compounds before capillary gas chromatography (GC) with flame-ionization detection. For whole blood, extraction efficiencies of 1-butanol, ethyl acetate and isoamyl acetate were 8.72-31.1%, and those of IS, butyl acetate, toluene and benzene were 42.9-74.1%. For urine, those of all compounds were 10.7-75.4%. The regression equations for six thinner components extracted from whole blood and urine were linear in the range of 3-500 ng/0.5 ml for ethyl acetate and 1-butanol, and 0.5-500 ng/0.5 ml for benzene, toluene, butyl acetate and isoamyl acetate. The detection limits for each of the components were 0.25-1.5 ng/0.5 ml for both samples. The coefficients of within-day and day-to-day variation for all components were satisfactory and not greater than 11 and 13%, respectively. The data obtained from actual determination of ethyl acetate, benzene and toluene in rat whole blood and urine after inhalation of the compounds were also presented.

Journal Article↗

PubMed1999

Metabolic fate of a new histamine H2-receptor antagonist, Z-300, in rat.

1. The metabolisms of (N-[3-[3-(piperidinomethyl)-phenoxy]-propyl]-2-(2-hydroxyethyl-1-t hio) acetamide.2-(4-hydroxy benzoyl) benzoate) (Z-300) in rat have been studied. 2. Five metabolites were identified, namely as sulphoxide (SO), sulphone (SO2), phenol (PH), propionic acid (PA) and thioglycolic acid (TH) derivatives. Furthermore, two metabolites, M1 and M2, were proposed as PH conjugated to sulphate and glucuronic acid respectively. 3. There were several metabolites in the plasma samples after oral administration of 14C-Z-300. The main metabolites were PH (mainly existing as the conjugates), PA and SO, and Z-300 was present as <10% of plasma radioactivity. SO2 and TH were barely detected in plasma. In the urine, the composition of metabolites was similar to that in the plasma. In the bile, the main metabolites were PH (mainly existing as the conjugates) and SO, and very little Z-300 was detected. In the faeces, the main compounds were Z-300 and TH, and very little SO. 4. During in vitro metabolism experiments, Z-300 was metabolized mainly in the liver, and a little in the kidney and lung. PH or its conjugates were produced little on the in vitro metabolism; this was different from that found in the in vivo experiment. The metabolism of Z-300 to SO appeared to be catalysed by cytochrome P450 rather than the flavin-containing monooxygenase. Both hepatic clearance calculated from the in vitro metabolism experiment (28.9 ml/min/kg) and from the liver perfusion metabolism experiment (33.2 ml/min/kg) were lower than the total clearance from the in vivo experiment (119 ml/min/kg). 5. After administration of 14C-SO into the caecum of rat, SO was converted to Z-300 and excreted in the faeces. 14C-SO was reduced by incubation for 4 h within the caecal content of rat under an anaerobic condition in vitro. The results suggest that SO was reduced to Z-300 by gut flora in the lower intestine.

Acetamides↗

PubMed1999

Pharmacokinetics of a new histamine H2-receptor antagonist, Z-300, in rat and dog.

1. The plasma level of Z-300 reached a maximum (Cmax) at 30 min after the oral administration of Z-300 to dog, and disappeared from the systemic circulation with a half-life of 8-9 h. The bioavailability of Z-300 was 52% after the oral administration of Z-300, 3 mg/kg. At doses ranging from 3 to 30 mg/kg, Cmax and AUC (area under the plasma concentration-time curve) were proportional to the dose. 2. The plasma level of Z-300 reached Cmax at 10 min after the oral administration of Z-300 to rat, and disappeared from the systemic circulation with a half-life of 0.8-1.6 h. The bioavailability of Z-300 was 39% after the oral administration of Z-300, 10 mg/kg, and there was a non-linear relationship between the plasma level-time profile of Z-300 and the administered dose (3-50 mg/kg). 3. The binding of Z-300 to plasma protein was 92% in man, 65% in dog and 25% in rat. It is suggested that these species differences were due to the content of alpha1-acid glycoprotein (alpha1-AG), because Z-300 bound more strongly to alpha1-AG than to albumin.

Acetamides↗

PubMed1999

Profound hearing loss attributable to cochlear nerve disease: diagnosis with combination of otoacoustic emission and magnetic resonance imaging.

OBJECTIVE: To detect the causes of deafness based on the combined findings of auditory brainstem response (ABR), distortion product otoacoustic emissions (DPOAEs), and three-dimensional Fourier transformation-constructive interference in steady state (3DFT-CISS) magnetic resonance imaging (MRI). STUDY DESIGN: Retrospective review of the medical records of 13 patients with unilateral profound hearing loss since childhood. METHODS: Subjects were tested with pure-tone audiometry, ABR, DPOAEs, and 3DFT-CISS imaging. RESULTS: No significant components of ABR were observable in any of the deaf ears. In 10 cases, the cochlear nerves of the deaf ears were found to be as normal as the healthy sides by 3DFT-CISS imaging, and no significant levels of DPOAEs were recorded. In the other three cases, no apparent cochlear nerves were identified by 3DFT-CISS imaging. Although no significant levels of DPOAEs were observable in two cases with cochlear nerves invisible by the MRI study, almost the same level of DPOAEs as that in the healthy side was recorded in the last case. CONCLUSIONS: In the last particular case, the cochlear nerve seemed to be mainly responsible for the profound deafness. 3DFT-CISS imaging in combination with preexisting audiological measures may provide direct evidence for the cochlear nerve disease. steady state, internal auditory canal, cochlear nerve disease.

Audiometry, Pure-Tone↗

PubMed1999

Anorexia nervosa with severe liver dysfunction and subsequent critical complications.

A twenty-year-old woman with anorexia nervosa (body mass index=11) suffered from severe liver dysfunction (aspartate aminotransferase 5,000 IU/l, alanine aminotransferase 3,980 IU/l, prothrombin time 32%), hypoglycemia (serum glucose 27 mg/dl), and pancreatic dysfunction (amylase 820 IU/l, lipase 558 IU/l). She fell into a depressive state with irritability, which was not improved by intravenous glucose. Despite treatment with plasmapheresis for the liver dysfunction, she subsequently developed pulmonary edema, acute renal failure, gastrointestinal bleeding, and disseminated intravascular coagulation. Hemodialysis, mechanical ventilation and drug therapy including prednisolone, prostaglandin E1, and branched-chain amino acid, improved her critical condition. In this case, malnutrition may have been the cause for the liver dysfunction and subsequent complications.

Acute Kidney Injury↗

PubMed1999

Pituitary metastasis from carcinoma of the urinary bladder mimicking pituitary apoplexy--case report.

A 70-year-old male presented with pituitary metastasis from transitional cell carcinoma of the urinary bladder manifesting as sudden headache, transient unconsciousness, and visual disturbance mimicking apoplexy of pituitary adenoma. Computed tomography showed a suprasellar tumor with intratumoral and intraventricular hemorrhage. Magnetic resonance imaging demonstrated an intra- and suprasellar mass lesion mimicking pituitary adenoma. Diabetes insipidus developed soon after. The tumor was subtotally removed. Histological examination revealed transitional cell carcinoma. An intratumoral hemorrhage may be associated with a pituitary metastasis if the patient presents with symptoms such as pituitary apoplexy.

Aged↗

PubMed1999

Ruptured cerebral pseudoaneurysm caused by the removal of a ventricular catheter. Case report.

A rare case of cerebral pseudoaneurysm located at the internal carotid artery (ICA) was caused by the removal of a ventricular catheter in an infant. This 4-month-old girl underwent ventriculoperitoneal shunt revision, during which the old ventricular catheter was removed from the posterior horn of the left lateral ventricle, but the choroid plexus was pulled out by the tip of the catheter. Intraventricular hemorrhage (IVH) and subarachnoid hemorrhage were observed postoperatively. Magnetic resonance (MR) angiography performed on the 12th postoperative day revealed ICA stenosis and aneurysm formation at the C1 portion of the left ICA. Contrast-enhanced computerized tomography (CT) scans obtained on the 21st postoperative day revealed recurrent IVH and enlargement of the lesion. The patient underwent surgery for treatment of the aneurysm. Operative findings revealed a pseudoaneurysm arising from the left ICA at the proximal end of the anterior choroidal artery (AChA). The aneurysm was removed and the wall of the ICA was reconstructed. Postoperative three-dimensional CT scanning and MR angiography demonstrated disappearance of the aneurysm and preservation of the ICA. The patient was discharged without additional neurological deficits. Many complications, including IVH, are associated with removal of a ventricular catheter. This case shows that pseudoaneurysm formation can occur in a remote region due to avulsion of the AChA from the ICA. In most circumstances a ventricular catheter can be removed without difficulty. However, precision and caution should be exercised when removing a ventricular catheter.

Aneurysm, False↗

PubMed1999

The relationship between cerebral infarction and angiographic characteristics in childhood moyamoya disease.

BACKGROUND AND PURPOSE: In childhood-onset moyamoya disease, the angiographic disease process of stenoocclusive lesions is progressive, and cerebral infarctions often develop as a result of ischemia. Our purpose was to determine how the severity of stenoocclusive lesions in the anterior and posterior circulations affects the distribution of cerebral infarction in patients with childhood-onset moyamoya disease. METHODS: In 69 patients with childhood-onset moyamoya disease, angiograms were reviewed for stenoocclusive lesions, and CT scans, MR images, or both were reviewed for the sites and extent of cerebral infarction. The relationship between the angiographic and CT/MR findings was examined. RESULTS: The prevalence and degree of stenoocclusive lesions of the posterior cerebral artery (PCA) significantly correlated with the extent of lesions around the terminal portion of the internal carotid artery (ICA). The prevalence of infarction significantly correlated with the degree of stenoocclusive changes of both the ICA and PCA. Infarctions tended to be distributed in the anterior borderzone in less-advanced cases, while in more advanced cases lesions were additionally found posteriorly in the territory of the middle cerebral artery, the posterior borderzone, and the PCA territory. CONCLUSION: Our results indicate that progressive changes of the anterior and posterior circulations are associated with the distribution of cerebral infarction, culminating in a patchily disseminated or honeycomb pattern of infarction on CT and MR studies in late stages of the disease.

Adolescent↗

PubMed1999

Effects of forced walking stress on formalin-induced paw licking in mice.

This study examined the effects of exposing mice to forced walking stress on formalin-induced paw licking. At each observation period (0.5-6 h) after exposure to forced walking stress, a significant antinociceptive effect (stress-induced analgesia, SIA) was observed only in the second phase (from 10 to 30 min), but not in the first phase (from 0 to 10 min) of formalin-induced paw licking in mice. The present data showed that SIA induced by exposure to forced walking stress was dependent on duration of the stress (0.5-4 h). SIA was dose-dependently antagonized by the NMDA receptor antagonist dizocilipine (0.01-0.04 mg/kg) but not by naloxone (10 mg/kg). Thus, the present results suggest that exposure to forced walking stress could cause SIA which may be involved in the nonopioid system via NMDA receptors.

Analgesia↗

PubMed1998

Comparison of ipsilateral activation between right and left handers: a functional MR imaging study.

We used fMRI to compare the ipsilateral activation in the sensorimotor region (SMR) during dominant and non-dominant hand motor tasks between right and left handers. In right handers, the ipsilateral activation was significantly greater during non-dominant (left) hand task than dominant (right) hand task, while in left handers, it showed no significant difference. The ipsilateral activation was most pronounced in the precentral subregion (presumably corresponding to the premotor area) during either hand task in both groups. We conclude that the different patterns of ipsilateral activation might be mainly explained by the hemispheric dominance. The skill of the hand and complexity of tasks may be related to the predominant activation of the premotor area.

Adult↗

PubMed1998

Hemorrhage in pituitary adenoma: correlation of MR imaging with operative findings.

The aim of this study was to correlate MR imaging and operative findings of hemorrhage in pituitary macroadenomas. We retrospectively reviewed MR images of 113 surgically proven pituitary adenomas. All patients were examined on a 1.5-T MR system. The intensity of intratumoral cystic cavities was correlated with operative findings. In 15 patients with pituitary apoplexy, we determined relationship between interval of MR examination after apoplectic event and MR signal intensity. In 8 patients with repeated preoperative MR examination, we evaluated sequential changes of intratumoral hemorrhage. There were 54 cavities at surgery: 52 were hemorrhagic and 2 were nonhemorrhagic. Twenty-nine of 52 hemorrhagic cysts demonstrated high/low signal (H/L) fluid-fluid levels on T2-weighted image (T2WI). In 19 of them, two components could be separately seen at operation: the supernatant high-intensity area represented xanthochromic fluid, and the dependent low-intensity area represented liquefied hematoma. The H/L fluid-fluid level was observed predominantly in hematomas on MR images obtained after longer intervals. In patients with repeated MR examination, follow-up MR imaging revealed additional hemorrhage or new formation of fluid-fluid levels. It was surprising that 12 of 14 cysts preoperatively judged as nonhemorrhagic in fact contained hemorrhagic components. The preoperative MR images are well correlated to the operative findings in hemorrhagic pituitary macroadenomas. It proved that 52 of 54 cystic cavities had hemorrhagic component.

Adenoma↗

PubMed1998

Retinoblastoma protein expression and prognosis in laryngeal cancer.

Expression of retinoblastoma (Rb) protein was immunohistochemically examined in laryngeal squamous cell neoplasias from 72 patients. Staining patterns were considered with reference to such prognostic factors as patient's age, histologic grade, tumour size and lymph node status, and 5-year survival rate. Rb protein negativity, either partial or complete, was noted in 28.8% of cases and was associated with a significantly lower 5-year survival rate, as well as with a higher likelihood of lymph node metastasis. This suggests that Rb alteration may be a prognostic indicator in patients with laryngeal carcinoma.

Adult↗

PubMed1998

Usefulness of neuroendoscopy in treating supracollicular arachnoid cysts--case report.

A 12-year-old girl presented with a supracollicular arachnoid cyst manifesting as a compressive headache. Neurological examination on admission revealed no deficit except bilateral papilledema. Stereotactic cyst puncture failed to perforate the cyst wall. The wall was then punctured using microforceps under neuroendoscopic guidance, followed by cystoperitoneal shunting. Her headache disappeared immediately after surgery. Neuroendoscopy is useful in treating a deep-seated arachnoid cyst.

Arachnoid Cysts↗

PubMed1998

[Induction of rhythmical activity in digastric muscles in an in vitro brainstem preparation from adult mice].

In this study, it was attempted to induce masticatory movements in an in vitro brainstem-spinal cord preparation isolated together with the orofacial structure from adult mice. The preparation was perfused intra-arterially with an artificial cerebrospinal fluid (ACSF) containing dextran through a cannula fixed to the descending aorta, and was placed in a bath perfused with the ACSF. Repetitive electrical stimulation of the medullary pyramidal tract (MPT) induced rhythmic EMG activities in the digastric muscle (3.8-7.2 Hz). Bath and intra-arterial application of kynurenic acid (KYN) or D, L-2-amino-5-phosphonovaleric acid (APV) suppressed the rhythm. During application of KYN, the rhythmic EMG activity in the digastric muscle could not be induced, even though the intensity of stimulation was raised. On the other hand, during application of APV, stimulation at a higher intensity induced rhythmic EMG activities with a lower frequency and a smaller amplitude. The results showed that glutamate is involved in induction of the rhythmic EMG activities by stimulation of the MPT, and that excitatory effects via the N-methyl-D-aspaltic acid receptor is not indispensable for its induction.

2-Amino-5-phosphonovalerate↗