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Biomedical subjects

M Nagase

Publications and source records attributed to M Nagase.

At least 109 records · Page 6Linked to original sources
PubMed1994

[Anesthetic management of a patient with adrenocorticotropic hormone (ACTH) deficiency].

A 73 year old woman with ACTH deficiency was admitted to our hospital for gastrectomy. She had taken corticosteroid for 3 years. The day before surgery, she took 25 mg of hydrocortisone per os. Hydrocortisone 100 mg was administered intravenously 30 minutes before surgery, during and after surgery, and on the next day after surgery. Serum concentrations of ACTH and cortisol were measured 1 hour after the first administration of hydrocortisone 100 mg, 2 hours after the second and 15 hours after the third administration. The ACTH concentration was always lower than the lowest limit of detection. Cortisol concentrations were 140.0, 180.0 and 14.5 micrograms.dl-1 at each measurement. Serum concentration of aldosterone after the induction of anesthesia was lower than the normal range. Her hemodynamics were very stable and electrolytes balance was not disturbed with corticosteroid treatment during and after surgery.

Adrenocorticotropic Hormone↗
PubMed1994

Stereotyped behavioral responses to an auditory stimulus in the course of repeated treatment with methamphetamine plus scopolamine and methamphetamine in rats.

The present experiment was designed to study the effects of an auditory stimulus with 300 Hz, 100 dB on gradual emergence of behavioral sensitization in the course of repeated administration of methamphetamine (MAP) in combination with scopolamine (SCOP) and MAP. Repeated intraperitoneal injection of MAP (4.0 mg/kg) plus SCOP (0.5 mg/kg) induced significantly progressive and enduring enhancement of stereotyped behavior, resulting in intense, focussed stereotypy intermingled with gnawing and licking compared to repeated MAP treatment. Vigorous stereotyped behavior induced by repeated MAP plus SCOP was progressively attenuated by the tone, resulting in attenuation of the development of behavioral sensitization. Conversely, the tone had no invariable effects on behavioral sensitization induced by repeated MAP treatment. The present findings indicate that repeated MAP plus SCOP treatment progressively induced attenuating effects of tone as low as 300 Hz on MAP plus SCOP-induced intense stereotypy and vigorous behavioral sensitization. These findings suggest that a reciprocal balance between dopaminergic and cholinergic inhibitory systems may be involved in producing behavioral sensitization, and in the attenuating effects of the tone on MAP plus SCOP-induced vigorous behavioral sensitization.

Acoustic Stimulation↗
PubMed1994

[Anesthesia for a pregnant patient with ruptured cerebral arterio-venous malformation].

A 29 year old woman suffered sudden hemiplegia, vomiting and headache during the 28th week of her first pregnancy. She was diagnosed as the intracranial hemorrhage due to the ruptured arteriovenous malformation, and emergency operation was performed. Anesthesia was induced with crush induction using thiamylal, fentanyl, pancuronium and suxamethonium, and maintained with fentanyl, isoflurane and nitrous oxide in oxygen. During and after surgery, fetal heart rate and uterine contraction were monitored continuously. Intense hypotension was not chosen because it may place a fetus at risk of intrauterine asphyxia. Ventilation was controlled to maintain PaCO2 between 30 and 35 mmHg. During surgery, D-mannitol 60 g was infused slowly to prevent fetal dehydration, and after surgery no osmotic diuretics were used. Ritodrine hydrochloride, which prevented premature delivery, was continuously infused after surgery. Her neurological symptom was improved and her baby was delivered vaginally at 41st gestational week.

Adult↗
PubMed1994

Low serum aminotransferase activity in patients undergoing regular hemodialysis.

Of 150 patients undergoing regular hemodialysis (HD), 14 (9.3%) and 12 (8.0%), respectively, showed low serum activity of aspartate aminotransferase (AST) and alanine aminotransferase (ALT). An investigation was conducted to elucidate the underlying mechanisms in 20 patients with low serum AST and/or ALT activity. Fifty-five percent of the patients with low aminotransferase activity manifested serum levels of pyridoxal phosphate (PLP) that were lower than normal. Serum PLP levels correlated neither with AST nor with ALT activity. Oral administration of vitamin B6 to the cases with low aminotransferase activity resulted in an increase in pre-hemodialysis aminotransferase activity. Addition of vitamin B6 in vitro to the sera from the patients with low aminotransferase activity did not increase the values when the added vitamin B6 was within the physiological range, but did increase when added in larger (pharmacological) amounts. However, aminotransferase activity increased, but PLP levels remained unchanged when these values were compared before and after HD. On the other hand, guanase being within the normal range in all cases studied, did not change after HD. Although our study does not correlate with vitamin B6 deficiency, but rather with some uremic substance(s) which interfere(s) with the enzyme reaction as a cause of low aminotransferase activity, the fact that less than 10% of our patients showed low AST and/or ALT points to the latter possibility, suggesting the need of further study.

Adult↗
PubMed1994

[The effects of hyperventilation upon the spinal pain modulating system (second report)].

The purpose of this study is to investigate the effect of hyperventilation on the spinal pain modulating system by using naloxone. Under enflurane anaesthesia, cats were prepared with midcollicular decerebration and lumbar laminectomy. The spinal cord was transected at T12-L1. WDR cells, responding primarily to noxious peripheral stimuli, were sampled with a microelectrode at the depth of 2,000 microns from the cord dorsum. Following the control period, ventilation was adjusted to produce hypocapnia of PCO2 20-25 mmHg. After activities of WDR cells were well suppressed, naloxone 0.1 mg.kg-1 was given intravenously. Changes of firings of WDR cells were investigated. Returning to normocapnia, recovery of firings was followed. Hypocapnia of PCO2 20-25 mmHg significantly suppressed the activities of WDR cells. Naloxone significantly antagonized the suppressive effects of hyperventilation upon the activity of WDR cell. Our results suggest that the hyperventilation has suppressive effects on single-unit activity of WDR cell and the mechanisms of those suppressive effects are related to pain modulating system by endogenous opiates.

Action Potentials↗
PubMed1993

The effect of crystallinity on hydroxyapatite-induced production of reactive oxygen metabolites by polymorphonuclear leukocytes.

To assess the role of crystallinity in biological response, we quantitated the generation of reactive oxygen metabolites in human polymorphonuclear leukocytes (PMN) with a chemiluminescence assay using three hydroxyapatite preparations with sintering temperatures of 1,200 degrees C and 900 degrees C and a drying temperature of 110 degrees C on the basis of equal weights (1 mg/ml). These crystals have almost the same average diameters and similar average zeta potentials. The crystals prepared at higher temperatures have higher crystallinity, or larger domain sizes, which were calculated by X-ray diffraction line broadening. The production of reactive oxygen metabolites by PMN in hydroxyapatite of 1,200 degrees C was 10-times that by PMN in hydroxyapatite of 900 degrees C and more than 50-times greater than that in hydroxyapatite of 110 degrees C. A single linear correlation was observed for a plot of log (peak chemiluminescence levels) vs. a plot of log (domain sizes). These results clearly show that the maximal effect of crystallinity on hydroxyapatite-induced production of reactive oxygen metabolites by human PMN was seen at higher crystallinity.

Crystallization↗
PubMed1993

Intra-GBM site of the functional filtration barrier for endogenous proteins in rats.

The passage of various endogenous proteins [such as albumin, transferrin, immunoglobulin G (IgG), and immunoglobulin M (IgM)] across GBM was studied in vivo in normal Munich-Wistar rats. Glomeruli were fixed by three different methods: in situ drip-fixation, perfusion- and immersion-fixation; then they were processed for immunogold electron microscopy. The most reproducible results were obtained with in situ drip-fixation. Albumin, transferrin and IgG penetrated into GBM, but IgM did not. Morphometry revealed that density of albumin increased towards the inner 1/5 to 1/3 of GBM (junction of lamina rara interna and lamina densa) and decreased towards the subepithelial region of GBM, whereas density of IgG and transferrin was the highest at the subendothelial site and declined towards the subepithelial side of GBM. These findings suggest that central and/or outer zone of GBM constitute the main filtration barrier for albumin, and that subendothelial zone may contribute also to the charge-selective barrier. It is also suggested that the subendothelial zone acts more effectively as a filtration barrier for IgG and transferrin than for albumin. In the outer zone of GBM, which roughly corresponds to lamina rara externa visualized by conventional electron microscopy, the relative density of IgG and transferrin was higher than that of albumin. Since the pI of albumin was lower than that of IgG and transferrin, this finding suggests that subepithelial zone of GBM also acts as a charge-selective barrier. In conclusion, the main GBM filtration barrier for albumin might be the central and outer zones of GBM, and that for transferrin and IgG might be the entire width of GBM.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗
PubMed1993

Specific increases in urinary excretion of anti-DNA antibodies in lupus mice induced by lysozyme administration: further evidence for DNA-anti-DNA immune complexes in the pathogenesis of nephritis.

We previously reported that lysozyme electrostatically inhibits the fibronectin-mediated DNA binding to the glomerular basement membrane (GBM) and reduces in situ DNA-anti-DNA complex formation in the GBM in NZB/W F1 mice [1]. In this study, we further noticed significant increases in urinary excretion of anti-DNA antibodies and immune complexes (IC) in lysozyme-treated NZB/W F1 mice. Their clearance ratios of IgG anti-DNA antibody to whole IgG were markedly high compared with those of saline-treated animals. A large number of IgG and C3 positive granules were observed in the tubular cells of NZB/W F1 mice treated with lysozyme. On the contrary, nil or only small amounts of anti-DNA antibodies were detected in the urine of NZB/W F1 mice without lysozyme administration despite a large amount of proteinuria, suggesting entrapment of the antibodies in lupus glomeruli. Lysozyme neither inhibited the binding of anti-DNA antibodies to DNA or heparan sulphate nor did it displace anti-DNA antibodies and IC from the kidney homogenates of lupus mice. It thus appears that the inhibition of DNA binding to the GBM due to lysozyme reduced the entrapment of anti-DNA antibodies in the GBM, resulting in urinary excretion of the antibodies.

Animals↗
PubMed1993

Pharmacokinetics of meropenem in patients with various degrees of renal function, including patients with end-stage renal disease.

The pharmacokinetics of meropenem were studied after intravenous infusion in 13 patients grouped according to the impairment of their renal function. Creatinine clearance (CLCR) was greater than 50, 50 to 30, and less than 30 ml/min in groups I, II, and III, respectively. Two other groups, groups IV and V, each comprising four patients with end-stage renal disease (CLCR, < 5 ml/min), were also studied, the former on days off of hemodialysis and the latter on days of hemodialysis. The elimination half-lives of meropenem were 1.54 +/- 0.70 h in group I patients, 3.36 +/- 1.02 h in group II patients, and 5.00 +/- 1.05 h in group III patients. Cumulative urinary excretion accounted for 48.5% of the dose in group I patients and decreased progressively with a decline in renal function. Hemodialysis shortened the elimination half-life of meropenem from 7.0 h to 2.9 h. H-4295, the main metabolite of meropenem, had a peak level in plasma of 0.5 to 1.0 h in patients with renal failure. The level of H-4295 decreased with hemodialysis. The dosing interval of meropenem should be prolonged in a regular proportion to the decline in CLCR (12 h in group II patients and 24 h in group III patients). In patients receiving hemodialysis, dosing after each hemodialysis session is recommended.

Adult↗
PubMed1993

Interstitial inflammatory and chronic tubulointerstitial lesions in lupus nephritis: comparison with those in IgA nephropathy.

The significance of interstitial inflammatory and chronic tubulointerstitial lesions was studied in relation to the severity of glomerular lesions in 62 patients with lupus nephritis and 88 with IgA nephropathy. Severe interstitial inflammatory and chronic tubulointerstitial lesions were found in patients with severe glomerular lesions in both lupus nephritis and IgA nephropathy. In such cases, the serum creatinine levels at biopsy were high and the renal prognosis was poor regardless of the underlying disease (lupus nephritis or IgA nephropathy). No IgA nephropathy patients with nil or mild glomerular lesions had moderate or severe interstitial inflammatory and/or chronic tubulointerstitial lesions. In contrast, predominantly severe interstitial inflammatory lesions were found in 36% of lupus nephritis patients with nil or mild glomerular lesions. The prevalence of interstitial immune complexes deposition was markedly high in those with predominant interstitial inflammatory lesions. However, the severity of chronic tubulointerstitial lesions was mild and renal function did not deteriorate in the mean follow-up periods of 68.6 months. It is suggested that, besides the tubulointerstitial lesions attributable to the severe concomitant glomerular damage, the interstitial deposition of immune complexes per se plays a pathogenic role in the interstitial inflammatory lesions in lupus nephritis. Its prognostic significance, however, was considered to be minor.

Adult↗
PubMed1993

Rearrangements of immunoglobulin and T-cell receptor genes in canine lymphoma/leukemia cells.

Tumor cells from 15 canine lymphoma/leukemia cases were examined for genetic rearrangements of immunoglobulin and T-cell receptor (TCR) genes in parallel with cell surface antigens. Ten of these 15 cases showed rearrangements of the immunoglobulin heavy chain (IgH) gene, while 4 cases displayed TCR beta-chain gene rearrangements on Southern blot analysis. All the cases with IgH gene rearrangements had multicentric form lymphoma, and 6 of the 10 cases were cell surface immunoglobulin-positive. On the other hand, the cases with TCR gene rearrangements included atypical lymphoma/leukemia cases, and 3 of the 4 cases were Thy-1 antigen-positive. Although the tumor cell lineage of a considerable number of lymphoma/leukemia cases could not be determined by phenotypic analysis, examination of the IgH and TCR gene rearrangements disclosed the lineages of 14 of 15 cases. Genetic analysis demonstrated that the tumor cells in most canine multicentric lymphomas were formed by clonal expansion of B-lymphocyte. These findings show that studies on the rearrangements of immunoglobulin and TCR genes are very useful for understanding the cellular origin, clonality and hierarchy of canine lymphoma/leukemia cells.

Animals↗
PubMed1993

[The effects of hyperventilation upon the spinal pain modulating system].

The purpose of this study is to investigate the effects of hyperventilation on the wide dynamic range (WDR) cell of the dorsal horn of the feline lumbar spinal cord. Cats received midcollicular decerebration and lumbar laminectomy. The spinal cord was transected at T12-L1. WDR cells were sampled with microelectrode at the depth of 2,000 microns from the cord dorsum. Following the control period with PaCO2 of 35-45 mmHg, respiratory rate and tidal volume were adjusted to make a level of hypocapnia as low as 20-25 mmHg. The recovery of cell activity was followed when normocapnia was restored. Hypocapnia with PaCO2 of 25-30 mmHg and 20-25 mmHg suppressed the activity of WDR cell significantly. At PaCO2 of 25-30 mmHg, the spontaneous activity was suppressed for about 20% and evoked activity for 27%. At PaCO2 of 20-25 mmHg, the spontaneous activity was suppressed for about 50% and evoked activity for 33%. The results suggest that the hyperventilation has suppressive effects on single-unit activity of WDR cell.

Action Potentials↗