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Biomedical subjects

K Higashi

Publications and source records attributed to K Higashi.

At least 163 records · Page 9Linked to original sources
PubMed1994

Effects of systemic cooling and rewarming on the evoked spinal cord potentials and local spinal cord blood flow in dogs.

Changes in evoked spinal cord potential (ESCP) and in local spinal cord blood flow (local SCBF) were measured simultaneously in eight dogs in the course of systemic cooling and rewarming using a water mattress. PaCO2 was maintained at 35-40 mm Hg (temperature-uncorrected values) by adjusting ventilatory volume every 1 degree C change of esophageal temperature under N2O (60%)-O2-isoflurane (1.15%) anesthesia. Local SCBF and arterial blood pressure decreased and ESCP latencies increased linearly with the decrease in body temperature to 23-24 degrees C. The conductive ESCPs (non-synaptic components) showed temporary augmentation in amplitude before eventual decrease under cooling. These showed a tendency to return to the precooling baselines after the initiation of rewarming. These results demonstrate that conductive ESCPs could be available for intraoperative monitoring of spinal function under hypothermia down to 23-24 degrees C.

Animals↗
PubMed1994

Brachial plexus injury with cough attack: case report.

Cough attacks elicited by movement of the neck and right arm are reported in a patient who had sustained several shoulder injuries and who had an anterior scalenectomy. The coughing was accompanied by weakness in the right upper limb. At exploration, the phrenic nerve was found adhered to the brachial plexus. The cough attacks disappeared, and the weakness of the right upper limb improved somewhat after lysis of the adhesions between the phrenic nerve and the plexus and after external neurolysis of the upper, middle, and lower trunks. Postoperatively, the patient could elevate his right arm without coughing.

Brachial Plexus↗
PubMed1994

Synthesis and antibacterial activity of new 2-substituted penems. II.

A series of new penems (4-17), having a bicyclic imidazole moiety as the C-2 substituent, has been synthesized. The antimicrobial activity of these compounds and their susceptibility to renal dehydropeptidase-1 (DHP-1) are elucidated, and their structure-activity relationships are discussed.

Anti-Bacterial Agents↗
PubMed1994

[Recent trends in research on lipoprotein metabolism].

New trends in the research works on lipoprotein metabolism are focused on four aspects, namely metabolism of remnant particles, VLDL's, LDL's and HDL's. Metabolic behaviors of remnants, VLDL's and HDL's are closely related to the concentration or percentage of small dense LDL particles which are more susceptible to oxidation. Hyperinsulinism and increased hepatic triglyceride lipase could be involved in these disorders.

Apolipoproteins↗
PubMed1994

[A study on the dosage of carboplatin for bronchial arterial infusion in combination with radiation therapy].

Radiation therapy holds an important position as one of the multidisciplinary methods of treating lung cancer (non-small cell carcinoma). As a result of the development of platinum preparations such as cisplatin (CDDP) and wide use of digital subtraction angiography (DSA), selective bronchial arterial infusion (BAI) therapy made possible more effective use of anti-lung cancer drugs. The use of radiation therapy in combination with BAI is now recommended as a more effective method. Meanwhile carboplatin (CBDCA) has recently been developed as a second generation platinum preparation with less side effects, and is being used for BAI, too. However, the maximum tolerated dose (MTD) of CB DCA for BAI to be used in combination with radiation therapy is not known yet. We, therefore, carried out a phase-study to determine MTD of CBD CA for combination with radiation therapy. The results show that the MTD of CBDCA is 400 mg/m2, and that clinically recommendable infusion limit is 350 mg/m2. In an angiographic study performed at the same time, a plural number of tumor affected blood vessels were found in 81.3% of the patients with lung cancer. Therefore, infusion of a drug for such patients should be carefully applied.

Aged↗
PubMed1994

Papaverine inhibits bile acid excretion in isolated perfused rat liver.

We investigated the effects of papaverine on bile acid excretion into bile in the presence of infusions of taurocholic acid, tauroursodeoxycholic acid, taurochenodeoxycholic acid and taurodehydrocholic acid in a single-pass, isolated perfused rat liver model. Although continuous infusion of papaverine (1.6 mumol/min) did not reduce bile acid excretion in the presence of low-dose (1.0 mumol/min) infusions of taurocholic acid or tauroursodeoxycholic acid, papaverine significantly inhibited biliary excretion of bile acids in the presence of low-dose taurochenodeoxycholic acid (-50%) and high-dose (3.0 mumol/min) taurocholic acid (-54%), tauroursodeoxycholic acid (-37%) and taurodehydrocholic acid (-31%). During continuous infusion of taurocholic acid (3 mumol/min), a 15-min infusion of papaverine (3.2 mumol/min) reduced bile acid excretion significantly; however, total uptake of bile acid was slightly decreased by the papaverine infusion. Bile acid excretion increased over the baseline value after the papaverine infusion was stopped and then returned to baseline. These results suggest that papaverine does not affect the uptake phase of bile acids at the sinusoidal membrane but may affect the intracellular transport phase or the excretory phase at the bile canalicular membrane. When taurocholic acid was infused at a constant rate of 3 mumol/min for 20 min without papaverine and then stopped, bile acid excretion decreased gradually and was nearly zero by 52 min. Cumulative bile acid excretion in the 52 min after the end of the infusion reached 3.3 +/- 0.2 mumol/gm liver and represented the storage capacity of the liver.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[Thyroid function abnormalities during interferon therapy].

One hundred and twenty patients with chronic hepatitis C were treated with a 6-month course of recombinant alpha-interferon (a daily dose of 6 MU i.m. for the first two weeks and 6 MU or 3 MU i.m. three times weekly thereafter). Serum levels of thyroxine (T4), triiodothyronine (T3), thyroid-stimulating hormone (TSH), antithyroglobulin antibody (TGHA) and antimicrosomal antibody (MGHA) were measured before and three month after treatment. Ten of 106 patients with normal thyroid function test before therapy developed thyroid dysfunction; five with hyperthyroidism, four with hypothyroidism and one with positive MCHA. Fourteen patients had thyroid function disorder before treatment. Seven of eight patients with positive MCHA, showed a rise in the titer during the treatment. These data showed that a small proportion of patients treated with interferon developed thyroid dysfunction during the treatment. The interferon-induced thyroid dysfunction appears to be caused via the immune system but also by acting directly on the thyroid gland.

Adult↗
PubMed1994

[Carpal tunnel syndrome: clinical experience of 61 cases].

Carpal tunnel syndrome (CTS) is the most frequent entrapment neuropathy. Appropriate diagnosis and therapy contribute to obtaining good results. We performed carpal tunnel release in 61 patients including 8 cases with chronic renal failure. They included 18 males and 43 females. Age distribution was from 28 to 76 years of age among the males, and from 29 to 82 years of age among the female patients. Bilateral operations were performed in 13 cases (male 5, female 8). Operations were carried out with local anesthesia in all cases except one. The skin incision was about 5 cm on the palmar skin. Hypertrophy of the transverse carpal ligament was found in all cases, with a thickness of 4 mm on the average. Usually, the ligament was as hard as gum in consistency. There were also hypertrophy of the subcutaneous connective tissue and palmar aponeurosis or aberrant muscle in some cases. In CTS following long-term hemodialysis for chronic renal failure, the ligament was very hard and appeared to be partly calcified. All patients improved clinically after the operation. We should understand the characteristic clinical symptoms and signs of CTS. Clinical worsening was prominent at night and/or early in the morning. Definite diagnosis was performed by electrophysiological means. Operative indications are 1) cases whose daily activities are disturbed due to severe symptoms with progressive aggravation, 2) cases with muscle weakness in the distribution of the median nerve, 3) cases with thenar atrophy, 4) cases which, electrophysiologically, are suspected of demyelination of the median nerve. As there were many unpredictable anomalies and variations among the lesions, correct decompression of the median nerve under direct vision is necessary during surgery.

Adult↗
PubMed1994

Inhibition of ethanol-induced inositol phosphate formation and Ca(2+) mobilization by okadaic acid in rat hepatocytes: evidence for a role of protein phosphatases in the modulation of phospholipase C by ethanol.

The effect of the protein phosphatase inhibitor okadaic acid on phospholipase C (PLC)-linked signal transduction processes was investigated in intact hepatocytes. A short (5 min) pretreatment of the hepatocytes with okadaic acid (1 mu M) markedly inhibited a subsequent stimulation of PLC by ethanol as well as by receptor-mediated stimuli (vasopressin and phenylephrine). Okadaic acid inhibited the agonist-induced hydrolysis of polyphosphoinositides, the accumulation of inositol trisphosphate (InsP(3)) and the increase in cytosolic Ca(2+) concentrations. The inhibition could be overcome by high concentrations of vasopressin or ethanol, but only partly so with phenylephrine. A comparison of the sensitivity of different agonists at similar rates of InsP(3) accumulation and Ca(2+) mobilization indicated that ethanol-induced PLC activation was more resistant to the effects of okadaic acid than the hormonal agonists. Moreover, the stimulation of PtdInsP kinase by ethanol, which accompanies PLC activation, was refractory to okadaic acid treatment. These findings suggest that receptor-mediated PLC activation is subject to multiple controls by phosphorylation-dephosphorylation, not all of which affect the actions of ethanol on this signal transduction system.

Animals↗
PubMed1993

A molecular basis for human hypersensitivity to aminoglycoside antibiotics.

We have investigated the distribution of mitochondrial DNA polymorphisms in a rare maternally transmitted genetic trait that causes hypersensitivity to aminoglycoside antibiotics, in the hope that a characterization of its molecular basis might provide a molecular and cellular understanding of aminoglycoside-induced deafness (AGD). Here we report that the frequency of a particular mitochondrial DNA polymorphism, 1555G, is associated nonrandomly with aminoglycoside-induced deafness in two Japanese pedigrees, bringing the frequency of this polymorphism to 5 occurrences in 5 pedigrees of AGD, and in 4 of 78 sporadic cases in which deafness was thought to be the result of aminoglycoside exposure; both frequencies are significantly different from the occurrence of this mutation in the hearing population, which was 0 in 414 individuals surveyed. The 1555G polymorphism occurred in none of 34 aminoglycoside-resistant individuals. We propose a specific molecular mechanism for aminoglycoside hypersensitivity in individuals carrying the 1555G polymorphism, based on the three-dimensional structure of the ribosome, in which the 1555G polymorphism favors aminoglycoside binding sterically, by increasing access to the the ribosome cleft.

Adolescent↗
PubMed1993

Induction of mitochondrial chaperonin, hsp60, by cadmium in human hepatoma cells.

Mitochondrial dysfunction is readily induced by a low level of cadmium both in vivo and in vitro. The gene expression of mitochondrial hsp60 was induced in a dose- and time-dependent manner and also in parallel with the accumulation of cadmium in mitochondria. The levels of hsp60 mRNA increased with time until 18 h, while the induction of heat shock 70 (hsp70) gene peaked at 6 h and then declined. On the other hand, the levels of metallothionein mRNA reached to a plateau at 6 h and were maintained at this level continuously. These results suggest that the regulatory mechanism and/or the signals for hsp60 induction by cadmium are independent from those of hsp70 and metallothionein.

Biological Transport↗
PubMed1993

Cloning, sequence and expression of the argG gene from Streptomyces lavendulae.

The argG gene, encoding argininosuccinate synthetase, was cloned from Streptomyces lavendulae KCCS0055 by colony hybridization using the argG-carrying 2.1-kb fragment of S. coelicolor DNA as a probe. The restriction map of the cloned DNA fragment was very similar to that of S. coelicolor. This DNA fragment could complement the argG mutation of both S. lividans 1326 I10 and Escherichia coli K-12 JE5694, suggesting that the fragment contained a promoter for both E. coli and S. lividans. The subcloning experiment using E. coli K-12 JE5694 as a host has indicated that the essential region for argG is contained in the 2.5-kb DNA fragment. The translational product was identified as a 56-kDa kDa protein in minicells and by conventional gel electrophoresis. Determination of the nucleotide (nt) sequence of the 2.5-kb DNA fragment revealed one open reading frame of 1449 bp. The amino acid (aa) sequence analysis showed that the N-terminus was Ser, and 9 aa from the N terminus were completely identical with those deduced from the nt sequence. Nuclease S1 mapping indicated that the transcription start point is located near the start codon.

Amino Acid Sequence↗
PubMed1993

An inhibitor of inositol-phospholipid-specific phospholipase C.

Q12713 substance, a cyclic peptide from Actinomadura spp., strongly inhibited the enzyme activity of phosphatidylinositol-4,5-bisphosphate-specific phospholipase C (PIP2-PLC) but scarcely inhibited other phospholipases. Kinetic analysis demonstrated that the inhibition of PIP2-PLC activity was competitive with respect to phosphatidylinositol 4,5-bisphosphate. Calcium and magnesium ions had no significant effect on the inhibitory activity. On the contrary, potassium or rubidium ion was essential for the inhibitory activity. Furthermore, NaF and AlCl3-stimulated increase of phosphoinositides was decreased by Q12713 in the cultured 3T3 cells.

3T3 Cells↗
PubMed1993

Simultaneous laser-Doppler flowmetry of canine spinal cord and cerebral blood flow: responses to PaCO2 and blood pressure changes.

We observed the relative changes of both spinal cord blood flow (local SCBF) and local cerebral blood flow (local CBF) using independent laser-Doppler flowmeters (LDF) in 12 dogs under N2O(50%)-O2-enflurane(1.0%) anesthesia. The dorsal surface of the lumbar spinal cord and the parietal surface of the brain were partially exposed. Two fine LDF probes were placed between the exposed surfaces and the dura maters at each site. Both local SCBF and local CBF decreased simultaneously with hyperventilation and increased with hypoventilation within several seconds. The local SCBF responses to PaCO2 changes were similar in direction and degree as those of the local CBF. Autoregulation of local SCBF to arterial blood pressure (ABP) changes was abolished, though that of the local CBF was still recognized in a blunted fashion within a mean ABP range of 50 to 150 mmHg.

Journal Article↗
PubMed1993

Cerebral cysticercosis: a case report.

A case of cerebral cysticercosis is reported in a 49-year-old female who presented with headache, nausea, and vomiting. Lumbar CSF showed the findings of mild aseptic meningitis. CT scan revealed an enlargement of the left ambient cistern and a small cystic lesion in the left frontal cortex. MRI demonstrated multilobular cysts in the left ambient cistern with enhancement of their capsules, which compressed and distorted the midbrain. The cysts were surgically excised, and histological examination of the specimen disclosed characteristic features of cysticercus with viable larva. An excellent value of MRI in the diagnosis of intracisternal cysticercosis is emphasized.

Brain Diseases↗