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Biomedical subjects

M Kaneko

Publications and source records attributed to M Kaneko.

At least 235 records · Page 13Linked to original sources

Interaction of intrathecally infused morphine and lidocaine in rats (part II): effects on the development of tolerance to morphine.

BACKGROUND: There has been little information regarding the effects of local anesthetics on tolerance to opioids, although chronic use of combination of opioids and local anesthetics is popular for pain control. This study was designed to examine the effects of lidocaine on morphine tolerance to somatic and visceral antinociception. METHODS: Rats received a continuous intrathecal infusion of morphine (0.3-10 microg x kg(-1) x h(-1)), lidocaine (30-1000 microg x kg(-1). h(-1)), a combination of those, or saline. After 6- day infusion, intrathecal morphine challenge test (5 microg/10 microl) was performed, and time-response curve was constructed to assess the magnitude of tolerance. The tail flick (TF) test and colorectal distension (CD) test were used to measure somatic and visceral antinociceptive effects, respectively. RESULTS: Antinociceptive effects in the TF and CD tests caused by morphine challenge were reduced (P < 0.01) in the morphine infused groups. The magnitude of the tolerance was inversely associated with the amount of morphine infused. Lidocaine infusion induced no different change in the morphine challenge test from that seen in the saline infusion group. Development of tolerance was greater in morphine 3 microg x kg(-1) h(-1) than in morphine 0.75 microg x kg(-1) x h(-1) + lidocaine 150 microg x kg(-1) x h(-1) despite their similar antinociceptive effects during intrathecal infusion. The infusion of a low dose of morphine (0.3 microg kg(-1) x h(-1)) did not reduce the antinociceptive effects in the challenge test. CONCLUSION: Lidocaine in combination with morphine does not reduce tolerance to morphine nor develop cross-tolerance. The intrathecal infusion of morphine induced tolerance to somatic and visceral antinociception in a dose-dependent fashion.

Analgesics↗

Pharmacokinetics and pharmacodynamics of SM-20302, a GPIIb/IIIa receptor antagonist, in anesthetized dogs.

We examined the pharmacokinetic and pharmacodynamic properties of SM-20302, a GPIIb/IIIa receptor antagonist, in anesthetized dogs. SM-20302 was administered intravenously in doses of 30 (n=2), 100 (n=4), 300 (n=4), and 1,000 microg/kg (n=4). The half-life of the initial phase was 4 min, and that of the terminal phase was 162-209 min. SM-20302 produced a dose-dependent increase in the initial plasma concentration and the area under concentration-time curve but did not alter the volume of distribution, mean residence time, or plasma clearance. Plasma clearance for SM-20302 ranged from 6.58 to 9.73 ml/min/kg. All doses of SM-20302 inhibited (> or =90%) the ex vivo platelet aggregation induced by adenosine diphosphate (ADP) or arachidonic acid (AA) in citrated platelet-rich plasma (cPRP). In heparinized PRP (hPRP), a dose-dependent (44-89%) inhibition was observed. By using a sigmoid Emax model, the in vivo median inhibitory concentration (IC50) for SM-20302 was estimated to be 14-19 ng/ml in cPRP and 79-89 ng/ml in hPRP. To validate the calculated parameters, an infusion regimen was designed for the prevention of coronary artery thrombosis. Infusion of SM-20302 produced 64-67% inhibition of platelets in hPRP and maintained vessel patency despite vessel wall injury. The results suggest that SM-20302 exhibits linear pharmacokinetics and that its ability to inhibit platelet aggregation in hPRP may correlate more accurately with its in vivo antithrombotic efficacy.

Animals↗

Expression of moesin and its associated molecule CD44 in epithelial skin tumors.

Moesin, one of the ERM (ezrin; radixin; moesin) family members, is directly associated with the cytoplasmic domain of CD44, which is now thought to be related to the metastatic potential of tumor cells. Using immunohistochemistry we investigated the expression of moesin in normal epidermis and various kinds of epithelial skin tumors: squamous cell carcinoma, verrucous carcinoma, Bowen's disease, solar keratosis, keratoacanthoma, basal cell carcinoma, and extramammary Paget's disease. Normal skin showed positive epidermal staining for moesin with the exception of the stratum corneum. The expression of moesin varied with the type of skin tumor. In basal cell carcinoma, Bowen's disease, and extramammary Paget's disease, moesin expression was either faint or negative. In contrast to Bowen's disease, invasive squamous cell carcinoma showed more intense and heterogeneous staining of the cytoplasm and the cell membrane. Verrucous carcinoma was weakly positive, with a tendency for the moesin to be distributed in the cell membrane. The staining pattern of moesin varied among the different kinds of epithelial skin tumors, and its expression was generally similar to that of the standard form of CD44. These results suggest that moesin is closely inter-related with CD44 in epithelial skin cells as seen in other cellular systems, and that the variable pattern of moesin staining among the skin tumor cells could reflect expression disorders associated with the transformation.

Carcinoma↗

Cloning of genes coding for the three subunits of thiocyanate hydrolase of Thiobacillus thioparus THI 115 and their evolutionary relationships to nitrile hydratase.

Thiocyanate hydrolase is a newly found enzyme from Thiobacillus thioparus THI 115 that converts thiocyanate to carbonyl sulfide and ammonia (Y. Katayama, Y. Narahara, Y. Inoue, F. Amano, T. Kanagawa, and H. Kuraishi, J. Biol. Chem. 267:9170-9175, 1992). We have cloned and sequenced the scn genes that encode the three subunits of the enzyme. The scnB, scnA, and scnC genes, arrayed in this order, contained open reading frames encoding sequences of 157, 126, and 243 amino acid residues, respectively, for the beta, alpha, and gamma subunits, respectively. Each open reading frame was preceded by a typical Shine-Dalgarno sequence. The deduced amino-terminal peptide sequences for the three subunits were in fair agreement with the chemically determined sequences. The protein molecular mass calculated for each subunit was compatible with that determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. From a computer analysis, thiocyanate hydrolase showed significant homologies to bacterial nitrile hydratases known to convert nitrile to the corresponding amide, which is further hydrolyzed by amidase to form acid and ammonia. The two enzymes were homologous over regions corresponding to almost the entire coding regions of the genes: the beta and alpha subunits of thiocyanate hydrolase were homologous to the amino- and carboxyl-terminal halves of the beta subunit of nitrile hydratase, and the gamma subunit of thiocyanate hydrolase was homologous to the alpha subunit of nitrile hydratase. Comparisons of the catalytic properties of the two homologous enzymes support the model for the reaction steps of thiocyanate hydrolase that was previously presented on the basis of biochemical analyses.

Amino Acid Sequence↗

Altered glucose metabolism in the hippocampal head in memory impairment.

OBJECTIVE: To evaluate the relevance of hypometabolism in the hippocampal head to the pathophysiology of memory impairment. BACKGROUND: Neurofunctional imaging studies with an image reslicing technique provided by using software suggest that dysfunction of the amygdalohippocampal system causes memory impairment. However, metabolic and morphologic profiles of the whole hippocampal formation have not been evaluated in detail. METHODS: By tilting the gantry of a high-resolution PET scanner in a plane parallel to the hippocampal longitudinal axis determined beforehand by MRI, we performed quantitative measurement of glucose metabolism in the subdivisions of the hippocampal formation (head, body, tail) in 10 patients of normal intelligence with pure amnesia, in eight patients with AD, and in eight normal subjects. RESULTS: Although the volumes of the amygdala and hippocampal formation in pure amnesics were not different significantly from those of normal subjects, glucose metabolism in the head of the hippocampus was significantly lower in pure amnesics. In patients with AD, marked hypometabolism was found extending to the amygdala, the hippocampal head, and the parietotemporal cortex, along with amygdalohippocampal atrophy. CONCLUSION: Hippocampal head dysfunction plays an important role in memory impairment in amnesic patients. Further metabolic impairment over the amygdalohippocampal system and the surrounding association cortex reflects the pathophysiology of AD.

Adult↗

[Interferon-alpha treatment for chemotherapy-resistant primary macroglobulinemia with stomach and lung invasion].

We reported a case of primary macroglobulinemia with stomach and pulmonary invasion. The patient was 71 years-old who had cervical lymphadenopathy and abdominal pain. Biopsy material of cervical lymph node showed non-Hodgkin's lymphoma, and he was diagnosed primary macroglobulinemia by IgM immunological histo-chemical staining of materials of stomach biopsies. Combination chemotherapies were not effective for the reduction of IgM-lambda protein, and organ invasion seemed to be progressive, so we tried interferon-alpha (IFN-alpha) to control M component. Daily injection of 6 megaunits of IFN-alpha induced significant reduction of M component and pulmonary invasion. This favorable changes were observed for 1 year. However, his pulmonary invasion on X-ray films relapsed and he died of respiratory failure by reason of severe pneumonia. IFN-alpha is currently available for myeloproliferative disease, especially chronic myelogenous leukemia and multiple myeloma. This case report showed that IFN-alpha was also available for primary macroglobulinemia.

Aged↗

Intradural retroclival chordoma without bone involvement: no tumor regrowth 5 years after operation. Case report.

Chordomas are most commonly located in the extradural region. A 56-year-old man presented with a large chondroid chordoma located totally within the intradural retroclival region. The tumor was resected via the petrosal approach. Five years after subtotal removal, the residual tumor showed no sign of regrowth despite the fact that radiation therapy had not been used. The patient was free of symptoms except for moderate, conductive hearing loss in his right ear. The position of the intradural tumor could be preoperatively diagnosed by neuroimaging and, thus, the petrosal approach was selected. Primary intradural extraosseous chordomas are very rare and difficult to differentiate from ecchordoses physaliphorae on the basis of histological and radiological features; however, MIB-1 staining may be useful.

Chordoma↗

Thrombolysis and angioplasty for acute occlusion of intracranial vertebrobasilar arteries. Report of three cases.

Three cases of intracranial vertebrobasilar occlusion were successfully treated in the acute stage by thrombolysis and angioplasty. All three patients were admitted to the hospital because of consciousness disturbance and other brainstem signs. Initial angiography revealed intracranial vertebrobasilar occlusions. At first, a microcatheter was introduced into the distal site of the occlusion and thrombolysis was attempted by using urokinase. Recanalization was achieved in all cases but severe stenosis of the intracranial vertebral and basilar arteries was found. The recanalization was followed by transluminal balloon angioplasty and the stenosis was successfully resolved. Marked neurological improvement was achieved in each case. Follow-up cerebral angiography demonstrated sufficient patency at the angioplasty site after 3 to 6 months. Residual severe stenosis of vertebrobasilar arteries after thrombolytic therapy carries the possibility of reocclusion. Combining angioplasty with thrombolysis to avoid rethrombosis and obtain sufficient distal blood flow is of significant benefit in treating vertebrobasilar occlusion.

Acute Disease↗

Palatal myoclonus induced by extirpation of a cerebellar astrocytoma. Case report.

A 45-year-old woman developed a rare case of palatal myoclonus with no other neurological signs after undergoing extirpation of a small cerebellar low-grade astrocytoma that was located in the right dentate nucleus. The palatal myoclonus has persisted for 4 years after the operation. Magnetic resonance T2-weighted imaging revealed a high-intensity lesion in the left inferior olive. Palatal myoclonus associated with the removal of cerebellar tumors is unusual but may easily be overlooked.

Astrocytoma↗

Inhibitory effect of ethanol administration on beta-alanine-2-oxoglutarate aminotransferase (GABA aminotransferase) in disulfiram-pretreated rats.

Ethanol in the presence of disulfiram (N,N,N',N'-tetraethylthiuram disulfide, an inhibitor of aldehyde dehydrogenase) inhibited liver beta-alanine-oxoglutarate aminotransferase (beta-AlaAT I) activity yet activated tyrosine aminotransferase (TAT) in weanling rats in vivo. The effect on beta-AlaAT I was followed by the inhibitory expression of beta-AlaAT I mRNA. The beta-AlaAT I activity was reduced with a pseudo-first-order profile with time, and the half-life was calculated to be 12.3 +/- 0.83 h with the rate constant (Kd) of 0.056 +/- 0.004 h-1. The synthesis of beta-AlaAT I in rat liver was estimated to be 1.56 x 10(-10) mol/g of wet tissue per hour at a steady state. A combination of ethanol and disulfiram also reduced beta-alanine-pyruvate aminotransferase (beta-AlaAT II) activity to 60% of the control after 24 h.

4-Aminobutyrate Transaminase↗

Cloning of rat dihydropyrimidine dehydrogenase and correlation of its mRNA increase in the rat liver with age.

Overlapping cDNAs encoding dihydropyrimidine dehydrogenase (DPD), the rate-limiting enzyme of pyrimidine degradation, were isolated from a rat liver cDNA library, and a 4,353 bp cDNA sequence with a 3,075 bp open reading frame encoding a polypeptide of 1,025 residues with a molecular mass of 111,458 Da was determined. Western blot analysis of COS-7 cells that were transfected with an RT-PCR-derived DPD cDNA showed that the product from the cDNA binds to an anti-serum for DPD. Northern blot analysis was performed by using a partial fragment of the cloned cDNA as a probe. The mRNA level, the protein level, and the activity of DPD in the rat liver increased to the adult level by 3 mo of age. The levels of DPD in the liver of adrenalectomized rats increased 48 h after glucocorticoid administration. The increase of DPD after birth may be caused by the increase in glucocorticoid level.

Aging↗

Mobile PCIS: point-of-care information systems with portable terminals.

We have developed a Point-of-Care Information System (PCIS) that uses portable terminals and supports the entire loop of daily nursing work for the first time. Nursing work includes a great deal of indirect nursing work, such as documenting patient information, conferring with other health-care providers, and so on, as well as direct patient care. The time needed for this indirect work often exceeds the time actually spent directly caring for patients and needs to be reduced. Our system was developed with the goal of doing this to make nursing work more efficient. The system consists of personal digital assistants (PDAs) that nurses carry in the hospital wards and a server computer located in the nursing station. The system has three main functions: 1) Data Browsing provides patient information such as a brief history, vital-sign charts, and handwritten notes; 2) Schedule Planning helps nurses organize doctors' instructions and make To-do lists for the day; and 3) Care Management reminds nurses when they should execute the doctors' orders and provides tools for data entry. These three functions cover the entire loop of daily nursing work. The PDAs and the server computer can share up-to-date information by data transmission through telephone lines (low-power cellular phones can be used), infrared devices, or RS-232C cables. Results from a preliminary hospital evaluation showed that use of the system can reduce the time needed for nursing documentation by 60% (a 10% saving of a nurse's total working time), and that more than 80% of the nurses who used the system felt it would make nursing work more efficient.

Attitude to Computers↗

Histological analysis of the aortic nerve in the rat raised in space (Rapid communication on Neurolab Project).

To study development of the aortic nerve baroreflex under conditions of microgravity, we examined the cross section of the left aortic nerve (LAN), which is the afferent of the baroreflex, in the neonate rats aged 25 days raised in microgravity on the space shuttle Columbia (flight:FLT group) for 16 days. In this paper, we report a part of the result obtained from the data of the myelinated fibers of LAN analyzed with an electron microscope. Two kind of ground control groups were compared to the FLT group; one was asynchronous ground control (AGC) group where the rats were housed in the same cage as that on the shuttle, and the other was vivarium(VIV) group where the rats were housed in a commercial cage. The LANs in each group were extirpated the from rats perfused with a fixative and embedded for histological analysis. We observed the transverse sections of LAN and took pictures of several areas (magnified to x 2K to x 200K). No irregular myelination was found in all fibers of FLT group when they were compared with two control groups. The thickness of myelin of the maximally myelinated fibers were 0.55 +/- 0.17 micrometer in FLT(n=5), 0.45 +/- 0.10 micrometer in AGC(n=5), and O.47 +/- 0.06 micrometer meter in VIV(n=5). There was no significant difference among three groups (unpared t-test). The results suggest that there is no effect of space environment on the myelin formation of each nerve fiber in the aortic nerve.

Animals↗

[Intraoperative coronary artery spasm treated by percutaneous cardiopulmonary support in a patient with left lung cancer].

A 53-year-old man with left lung cancer underwent left upper lobectomy and extended mediastinal lymphadenectomy. Shortly before the end of the operation, electrocardiogram showed elevation of ST wave and multiple ventricular premature contractures first, then ventricular fibrillations, and finally cardiac arrest. Coronary artery spasm was strongly suspected. The patient was resuscitated by cardiac massage and countershock immediately, however, such attacks repeated several times. As medication and cardiac pacing were not effective, percutaneous cardiopulmonary support (PCPS) was established. The hemodynamics was stabilized with PCPS. He was weaned off PCPS the next day. He was discharged and has had no attack so far. PCPS is an excellent modality for intraoperative coronary spasm which is uncontrollable by medicines and other methods.

Carcinoma, Squamous Cell↗

[Changes in the threshold values of lingua throughout aging].

The filter-paper-disk method was employed for measuring the threshold values of four basic taste on lingua-tip with 308 healthy females aged 20-79. Taste substance were sequentially diluted with distilluted water (30 stages from 80.0 g/dl for sucrose, 30 stages from 30.0 g/dl for NaCl, 30 stages from 8.0 g/dl for sodium tartrate, 30 stages from 4.0 g/dl for HCl quinine). The result was as follows. A sensibility of gustation decreased rapidly in accordance with aging. A decrease of bitterness sensibility was most remarkably with aging, succeeded sourness, sweetness, saltyness. Also, a decrease of a gustation sensibility is beginning in early twenties, especially the sensitivity to a sweetness and sour taste decreased conspicuously from twenties to thirties.

Adult↗

[Intra-arterial infusion chemotherapy for advanced endometrial cancer before surgical treatment].

Nine cases of advanced uterine body cancer (stage III: 8, stage IVa: 1) were treated by intra-arterial infusion chemotherapy before curative operation. This treatment produced primary tumors smaller than half sizes in eight cases. Necrotic changes were found in over two-thirds of the lesions in six cases. This chemotherapy enabled us to operate curatively in seven cases. After the operations, we performed various types of treatment including intra-arterial infusion chemotherapy. No evidences of disease have been found in four cases, but there is no significant difference between the groups receiving and not receiving the intra-arterial infusion chemotherapy (n = 16) in terms of survival rate of stage III. Further study of the prognosis is necessary.

Adenocarcinoma↗