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Biomedical subjects

J Harada

Publications and source records attributed to J Harada.

At least 55 records · Page 3Linked to original sources
PubMed1995

[MR imaging of infected spondylodiskitis: interval signal change in vertebral body (including enhanced image of vertebral body)].

A retrospective evaluation of MRI was carried out in 22 patients with spondylodiskitis. Low signal intensity on T1-weighted images and high or low signal intensity on T2-weighted images were observed. Sixteen patients underwent follow-up examinations after the initial examination. Various signal changes in the vertebral body were recognized. The longer the period of follow-up, the less abnormal the signal intensity became on both T1- and T2-weighted images. Several cases showed no change in signal intensity. In all of 17 patients re-examined after injection of Gd-DTPA, infected vertebral bodies were enhanced. We classified the enhancing patterns of infected vertebral bodies in three types: A) homogeneous, B) homogeneous with strong enhancement adjacent to the end plate, C) inhomogeneous. Pyogenic spondylodiskitis tended to show patterns A or B, and tuberculous spondylodiskitis pattern C. The enhancement effect disappeared after normalization or remission of laboratory findings. In two cases, the enhancement effect remained even after laboratory findings became normal. Contrast MRI was useful for understanding infectious state.

Adolescent↗
PubMed1995

[The clinical scoring system for predicting the risk of intraoperative and postoperative bronchospasm].

Patients with bronchial asthma (BA) are usually considered to have a high risk of developing bronchospasm (BS) during anesthesia. Our clinical scoring system for preoperative assessment in BA patients was used to predict the risk of intraoperative and postoperative BS. Thirty two patients with a history of BA were studied retrospectively, assessing preoperatively with our clinical scoring system; Bronchial Asthma Risk Index Score (BARIS). BARIS was composed of a total of ten items. Five of them were scored before inhalation of bronchodilators and remaining five items were scored after the inhalation. Each item was scored by 0, 1, or 2. Four of 32 patients developed BS peroperatively (BS group). Twenty eight patients developed no BS peroperatively (control group). The total scores of pre-inhalation five items were 4.8 +/- 1.9 in BS group and 2.0 +/- 1.3 in control group, and the total scores of post-inhalation five items were 4.0 +/- 1.4 in BS group and 1.3 +/- 1.0 in control group. There were significant differences between the two groups (P < 0.05, Mann-Whitney U-test). We conclude that BARIS is useful in evaluating the risk of peroperative bronchospasm in patients with a history of bronchial asthma.

Aged↗
PubMed1994

[Ability of subtraction and dynamic MR imaging to detect breast tumors: comparison with ultrasonography and mammography].

We evaluated the ability of subtraction and dynamic MR imaging to accurately detect breast tumors. Sixty-five breast carcinomas and 24 fibroadenomas were examined by an SE pulse sequence using a 0.2 Tesla unit. Subtraction MR images were obtained every minute during dynamic study with Gd-DTPA. Almost all breast tumors were seen as very bright masses, and the margin of the mass was clearly demonstrated on subtraction MR images. Breast carcinomas and fibroadenomas showed characteristic time-intensity curves on dynamic study, Time-intensity curves of the early peak type and plateau type were seen in 97% of breast carcinomas, while the gradually increasing type was seen in 92% of fibroadenomas. The detectability of breast carcinoma was 98% by MRI, 98% by ultrasonography, and 87% by mammography. That of fibroadenoma was 95% by MRI, 91% by ultrasonography and 60% by mammography. Sensitivity and specificity for breast carcinoma were 98% and 92% for MRI and 97% and 71% for ultrasonography. For fibroadenoma, they were 96% and 98% for MRI and 89% and 92% for ultrasonography.

Adolescent↗
PubMed1994

Brain energy metabolism and blood flow during sevoflurane and halothane anesthesia: effects of hypocapnia and blood pressure fluctuations.

The effects of halothane and sevoflurane on cat brain energy metabolism and regional cerebral blood flow (rCBF) were evaluated during normo- and hypocapnia. Brain energy status was evaluated with phosphorous nuclear magnetic resonance spectroscopy (31P-MRS) and rCBF was measured by the hydrogen clearance method. A high concentration of halothane (3 MAC) impaired brain energy metabolism, while even a higher concentration of sevoflurane (4 MAC) had no untoward effect on brain energy metabolism. At 3 MAC of halothane, there were measurable decreases in brain phosphocreatine (69% of the control) and increases in brain inorganic phosphate (about 250% of control Pi), even though CBF was about 70% of the control value. During hypocapnia, the phosphocreatine levels began to decrease at a Paco2 of 2.7 kPa with 2 MAC of sevoflurane (90% of the control), and at a Paco2 of 4.0 kPa with 2 MAC of halothane (92% of the control). rCBF had decreased to less than 50% of the control value when Paco2 was < or = 2.7 kPa with 2 MAC of sevoflurane and < or = 4.0 kPa with 2 MAC of halothane. Abnormal brain energy metabolism was only observed when rCBF was decreased to less than half of the control (non-anesthetized and normocapnic) value. Following administration of a vasopressor, metaraminol, the abnormal brain energy metabolism induced by 2 MAC of halothane at a Paco2 of 1.33 kPa was normalized in parallel with the improved rCBF values. We conclude that hyperventilation and fluctuating blood pressure contribute to the occurrence of abnormal brain energy metabolism during halothane and sevoflurane anesthesia. This is more pronounced with halothane than with sevoflurane. The hypocapnia-induced abnormality during exposure to 2 MAC of either agent was due to decreased CBF associated with low perfusion pressure, indicating that there was no direct effect of these anesthetics on cerebral energy metabolism.

Adenosine Triphosphate↗
PubMed1994

Prophylactic effects of pirenzepine (M1-blocker) on intraoperative stress ulcer: comparison with an H2-blocker.

Patients under general anesthesia were treated with either an H2-blocker, ranitidine 50 mg, or an M1-blocker, pirenzepine 10 mg, and the effects of the two drugs on the gastric mucosa were compared by the measurement of the gastric juice pH and viscosity. The results showed that pirenzepine increased the gastric juice pH sufficiently while maintaining the gastric juice viscosity, and that ranitidine maintained the gastric juice pH higher than pirenzepine while decreasing the gastric juice viscosity. These results suggest that treatment with pirenzepine may have advantages in the prevention of stress ulcers.

Adult↗
PubMed1994

Renin inhibitors. III. Synthesis and structure-activity relationships of transition-state inhibitors containing dihydroxyethylene isostere at the P1-P1 site.

The design, synthesis and structure-activity relationships of transition-state inhibitors containing the dihydroxyethylene isostere at the scissile site are described. The compounds with (2S,3R,4S)-4-amino-5-cyclohexyl-1-morpholino-2,3-pentanediol at the P1-P1 site are potent renin inhibitors. (2S,3R,4S)-4-[N-[(2S)-3-Ethylsulfonyl-2-(1-naphthylmethyl)propiony l]-L- norleucyl]amino-5-cyclohexyl-1-morpholino-2,3-pentanediol (2) (BW-175), which is the most potent inhibitor (IC50: 3.3 nM against human renin) in this series, poorly inhibits cathepsin D (IC50: 26000 nM) and pepsin (IC50: > 100000 nM), and thus it is specific for renin. Compound 2 contains only one amino acid and showed an oral bioavailability of 2.8% at 10 mg/kg and 9.7% at 30 mg/kg in rats. The interaction between renin and inhibitor 2 is discussed on the basis of molecular modeling studies.

Animals↗
PubMed1994

A study on the phase spectral analysis of middle latency response and 40-Hz event-related potential in central nervous system disorders.

The synchrony measure method, or SM method, a phase spectral analysis described by Fridman in 1984 for ABR, was applied to 40-Hz event-related potential (40-Hz ERP), and was found to be a useful method for automatic detection in predicting hearing thresholds across the audiometric frequencies. Although 40-Hz ERP was claimed by Galambos to be the summation of middle latency responses (MLR), its origin is still controversial. Moreover, only a few articles have reported on the clinical use of 40-Hz ERP in patients with neurological disorders. We recorded ABRs, MLRs, and 40-Hz ERPs in 59 patients with central nervous system (CNS) disorders, and analyzed the relationship between central lesions and MLR or 40-Hz ERP using phase spectral analysis. Abnormal findings in 40-Hz ERP were observed in 43 (72.9%) out of 59 cases with CNS disorders, and most of the abnormal cases had disorders involving the midbrain or thalamic lesions, especially on the side contralateral to stimuli. The results suggest that phase spectral analysis of 40-Hz ERP is useful in the detection of CNS disorders.

Acoustic Stimulation↗
PubMed1994

Phase spectral analysis of auditory brainstem response in cats.

In order to apply the phase spectral analysis of auditory brainstem response (ABR) to the clinical diagnostic test, the phase spectra of ABRs were investigated under adequate stimulus intensity in normal cats and after the destruction of acoustic nerve and brainstem auditory pathways in cats. The results were as follows; i) In normal ABRs, the phase spectra were mainly composed of three frequency components at 0-300 Hz (component A), 300-900 Hz (component B) and 900-1500 Hz (component C). ii) A greater decrease of the component synchrony measure (CSM) occurred if ipsilateral destruction was performed in a peripheral lesion. Lesions of the auditory pathway were followed by a decrease of the CSM of component C in response to contralateral stimulation. These results suggest that the phase spectral analysis of ABRs has significant clinical value in the detection of brainstem lesions.

Acoustic Stimulation↗
PubMed1994

A case of viral encephalitis with hyperthermia and status epilepticus: efficacy of dantrolene treatment.

A case of viral encephalitis is described. A 55-year-old female developed hyperthermia and status epilepticus. Herpes simplex virus was regarded as a factor since viral complex titres were elevated and decreased. In addition to acyclovir and anticonvulsive agents, dantrolene (150 mg/day) was administered orally through a nasogastric tube for heat stroke. Convulsions and hyperthermia gradually decreased and intravenous agents were replaced by oral agents. Dantrolene may be a useful adjuvant in hyperthermia and convulsions associated with encephalitis.

Anticonvulsants↗
PubMed1994

Cardiac metastasis of colon adenocarcinoma diagnosed by magnetic resonance imaging.

We report a case with right intraventricular metastasis of colon carcinoma which was diagnosed antemortem by the use of magnetic resonance imaging. Metastatic colon carcinoma of the heart is a rare diagnosis, and an uncommon finding at autopsy. We conclude that MR imaging is a valuable method for the diagnosis of the heart tumors.

Adenocarcinoma↗
PubMed1993

[Subtraction and dynamic MR images of breast cancer].

The purpose of this study was to evaluate the diagnostic effectiveness of subtraction and dynamic MR imaging in patients with breast masses. In 23 breast cancers and six fibroadenomas, spin echo T1 images were obtained at 0.2 Tesla before and every minute after the intravenous injection of Gd-DTPA (0.1 or 0.2 mmol/kg). Subtraction images were obtained sequentially on the CRT monitor. All breast masses were enhanced after gadolinium and stood out as bright lesions on subtraction images. The tumor margin and its extension were more precisely evaluated on subtraction MR images than on conventional postcontrast MR images. Breast cancer showed a characteristic time-intensity curve with an early peak, in contrast to fibroadenoma, which showed a gradual increase in signal intensity. Subtraction MR imaging is a simple method for the evaluation of breast masses, and further, the time-intensity curve obtained by dynamic study is helpful in the differential diagnosis of lesions.

Adenofibroma↗
PubMed1993

Brain energy metabolism and blood flow during sevoflurane and halothane anesthesia: effects of hypocapnia and blood pressure fluctuations.

The effects of halothane and sevoflurane on cat brain energy metabolism and regional cerebral blood flow (rCBF) were evaluated during normo- and hypocapnia. Brain energy status was evaluated with phosphorous nuclear magnetic resonance spectroscopy (31P-MRS) and rCBF was measured by the hydrogen clearance method. A high concentration of halothane (3 MAC) impaired brain energy metabolism, while even a higher concentration of sevoflurane (4 MAC) had no untoward effect on brain energy metabolism. At 3 MAC of halothane, there were measurable decreases in brain phosphocreatine (69% of the control) and increases in brain inorganic phosphate (about 250% of control Pi), even though CBF was about 70% of the control value. During hypocapnia, the phosphocreatine levels began to decrease at a PaCO2 of 2.7 kPa with 2 MAC of sevoflurane (90% of the control), and at a PaCO2 of 4.0 kPa with 2 MAC of halothane (92% of the control). rCBF had decreased to less than 50% of the control value when PaCO2 was < or = 2.7 kPa with 2 MAC of sevoflurane and < or = 4.0 kPa with 2 MAC of halothane. Abnormal brain energy metabolism was only observed when rCBF was decreased to less than half of the control (non-anesthetized and normocapnic) value. Following administration of a vasopressor, metaraminol, the abnormal brain energy metabolism induced by 2 MAC of halothane at a PaCO2 of 1.33 kPa was normalized in parallel with the improved rCBF values. We conclude that hyperventilation and fluctuating blood pressure contribute to the occurrence of abnormal brain energy metabolism during halothane and sevoflurane anesthesia. This is more pronounced with halothane than with sevoflurane.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Inhalation↗
PubMed1992

[MR imaging of degenerative lumbar disc disease emphasizing on signal intensity changes in vertebral body].

Magnetic resonance imaging was performed in 400 patients with degenerative disc disease. Signal changes and their sites in the vertebral body were classified and referred to narrowing of the intervertebral disc space. MR findings were compared with those of plain roentgenograms of the lumbar spine. Signal changes in the vertebral body were noted in 83 cases (102 vertebral bodies). Low-intensity abnormality on both T1- and T2-weighted images (WI) was the most common finding, and was most frequently seen at the end plate and/or the angle. These changes were correlated with narrowing of the disc space and osteosclerosis on the plain roentgenogram of the lumbar spine. Signal changes occasionally occurred in the inner region of the vertebral body, and these lesions tended to show a high-intensity abnormality on T1-WI. We conclude that signal changes in degenerative disc disease are not specific, but are sometimes difficult to distinguish from the signal changes in other conditions such as spinal tumor or bone marrow disorder.

Humans↗
PubMed1992

Affinity cross-linked delta-opioid receptor in NG108-15 cells is low molecular weight (25 kDa) and coupled to GTP-binding proteins.

The affinity cross-linking of the delta-opioid receptor in neuroblastoma x glioma NG108-15 cells was undertaken using (3-[125I]iodotyrosyl27)human-beta-endorphin ([125I]beta-endorphin) and disuccinimidyl suberate (DSS) or bis(sulfosuccinimidyl) suberate (BS3) in order to estimate molecular size. Following sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, two radioactive bands were observed. Labeling of a major band of 29 kDa diminished in the presence of unlabeled selective delta-opioid agonist, [D-Pen2,D-Pen5]enkephalin (DPDPE), in a concentration-dependent manner, while labeling of a minor band of 58 kDa was hardly affected. The labeling intensity of the 29 kDa band decreased by addition of guanosine 5'-(3-o-thio)triphosphate (GTP gamma S) or by pretreatment of cells with pertussis toxin. These results, taking the molecular weight of covalently bound beta-endorphin (3.6 kDa) into consideration, suggest that the delta-opioid receptor in NG108-15 cell membrane is a 25 kDa protein which is coupled to pertussis toxin-sensitive guanosine triphosphate-binding proteins (G-proteins).

Cell Membrane↗
PubMed1992

[Evaluation of cleft lip and palate by computed tomography with 2 mm thin slice scanning--Part 2].

Computed tomography was performed on 104 patients of cleft lip and palate with continuous 2 mm slice scanning. The type of hard palate was classified into 3 groups, as normal, hypoplasia and aplasia, depending on its developmental degree. The shape of alveolus was also grouped into 3 groups as circular, triangular and asymmetric forms for the evaluation of the maxillary development. The hard palate development correlated with the shape of the alveolus, the diameter of maxillary and mandibular bone, and frequency of sinusitis and otitis media. Evaluation of the hard palate by thin slice scanning is useful in presumption of future facial development.

Adolescent↗
PubMed1992

[The effects of sevoflurane/halothane anesthesia during normo- and hyperventilation on the energy metabolism of the cat brain].

Energy metabolism of the cat brain was studied using phosphorous-31 nuclear magnetic resonance (31P-NMR) during sevoflurane/halothane anesthesia with normo- and hyperventilation. Under normocapnia, the findings associated with abnormal energy metabolism were not observed at concentration of sevoflurane/halothane up to 2 MAC. Meanwhile under hypocapnia by hyperventilation, the value of phosphocreatine began to decrease at and below 20 mmHg of PaCO2 (2 MAC sevoflurane) and 30 mmHg of PaCO2 (2 MAC halothane) respectively. These abnormal findings of brain metabolism were limited to the cases with cerebral blood flow (CBF) of less than a half of control state (nonanesthetized and normoventilated), and they were normalized with increased CBF by the vasoconstrictor, metaraminol. From the above data, it was concluded that the deteriorated energy metabolism by hyperventilation was due to decrease in CBF with hypotension and there was no direct effect on cerebral metabolism with less than 2MAC of both sevoflurane and halothane.

Anesthesia, Inhalation↗
PubMed1992

[The effects of prostaglandin E1 infusion on the viscosity and pH of gastric fluid during general anesthesia].

We studied the protective effect of prostaglandin E1 (PGE1)-induced hypotensive anesthesia on gastric mucosa in 30 elective surgical patients. Three groups, each composed of 10 patients, received PGE1, nitroglycerin or none during general anesthesia. Then we measured the viscosity and pH of gastric fluid continuously in each group. In the PGE1 group the viscosity and pH increased significantly and rapidly (P less than 0.05) as compared with the other groups. This suggests that PGE1 offers prophylactic effect against postoperative acute gastric mucosal lesion (AGML).

Adult↗