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M Manabe

Publications and source records attributed to M Manabe.

At least 55 records · Page 3Linked to original sources
PubMed1988

Decrementing expiratory neurons of the Bötzinger complex. I. Response to lung inflation and axonal projection.

In Nembutal-anesthetized, immobilized, and artificially ventilated cats with intact vagus nerves, extracellularly recorded activities of expiratory (E) neurons whose firing patterns were of decrementing, or the early expiration type (E-DEC neurons) were recorded in the vicinity of the Bötzinger complex (BOT). A total of 32 E-DEC neurons which were not vagal motoneurons was studied by determining 1) where they were distributed, 2) how their firing was modulated by lung inflation, and 3) if they projected their axons to the respiratory area of the brain stem. E-DEC neurons were located ventromedially to the retrofacial nucleus and were intermingled with E neurons of the augmenting type (E-AUG neurons), which were abundant and representative of neurons in the BOT. Firing of 25 E-DEC neurons was facilitated by lung inflation, indicating the existence of excitatory input from stretch receptors of the lungs, although the firing of 7 other neurons was not affected. On the other hand, firing of surrounding E-AUG neurons was suppressed by lung inflation. The E-DEC neurons fired in the E phase during a brief stop of the ventilator, indicating that they received central respiratory rhythm. However, they almost never fired during the inspiratory (I) phase even when the lungs were strongly inflated, indicating the existence of strong central inhibition during the I phase. Eight E-DEC neurons were tested for antidromic activation from the contralateral brain stem and the spinal cord by microstimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1988

Decrementing expiratory neurons of the Bötzinger complex. II. Direct inhibitory synaptic linkage with ventral respiratory group neurons.

In Nembutal-anesthetized, immobilized and artificially ventilated cats, decrementing expiratory (E-DEC) neurons which were excited by lung inflation were isolated in the vicinity of the Bötzinger complex. Then intracellular recordings were made from the respiratory neurons in the contralateral ventral respiratory group (VRG). The intracellular membrane potentials were averaged using extracellular spikes of the E-DEC neurons as triggers (spike-triggered averaging method). Hyperpolarizing potentials locked to the triggering spikes were obtained and they were shown to be unitary IPSPs since their polarity was reversed when averaged during passage of hyperpolarizing current. The latencies of antidromic activation of the E-DEC neurons from the area of intracellular recordings were shorter by about 0.2 ms than those of unitary IPSPs. This showed that the connections were monosynaptic. A total of 47 pairs were analyzed and unitary IPSPs were found in 12 pairs. The E-DEC neurons inhibited both inspiratory and expiratory neurons, including bulbospinal inspiratory neurons, propriobulbar inspiratory neurons, and vagal motoneurons with expiratory activity. These inhibitory E-DEC neurons, receiving excitatory inputs from the stretch receptors of the lungs, presumably intervene in reflex loops such as the Hering-Breuer reflex and may make some contribution to normal breathing.

Action Potentials↗
PubMed1988

Axonal projections from Bötzinger expiratory neurons to contralateral ventral and dorsal respiratory groups in the cat.

We studied projection patterns of the augmenting expiratory neurons of the Bötzinger complex (BOT) in the contralateral brainstem. Three experimental approaches were used: 1) electrophysiological analysis using antidromic microstimulation, and morphological analyses using 2) intraaxonal injection of HRP, and 3) application of the anterograde tracer Phaseolus vulgaris leucoagglutinin (PHA-L). Taken together, the three methods revealed morphological details of the axonal arborizations of the expiratory neurons in the BOT and the ventral respiratory group (VRG). The majority of augmenting expiratory neurons of the BOT had axonal collaterals in the contralateral brainstem. The stem axons to the contralateral side crossed the midline almost at the level of the cell somata. They descended dorsomedial to the ventral spinocerebellar tract and gave off collateral branches directed dorsomedially. Terminal boutons were distributed abundantly in the caudal part of the BOT and in the more caudally situated VRG. Axon collaterals sometimes ran to the dorsal respiratory group (DRG) and distributed terminal boutons there. Together with the fact of extensive ipsilateral arborizations shown previously, the present results indicate that the augmenting expiratory neurons of the BOT have wide bilateral influence on the BOT, VRG, DRG, and spinal cord.

Animals↗
PubMed1988

Protease inhibitor therapy for recessive dystrophic epidermolysis bullosa. In vitro effect and clinical trial with camostat mesylate.

Recently we reported that a kind of serine protease, SH protease, and collagenase might be involved in blister formation and, furthermore, that the cooperative action of these three proteases was essential for blister formation in recessive dystrophic epidermolysis bullosa. In this study we examined the inhibitory effect of clinically usable serine protease inhibitors for blister formation in organ culture and in clinical trials of recessive dystrophic epidermolysis bullosa patients. Camostat mesylate, a synthetic serine protease inhibitor that is available for the treatment of chronic pancreatitis, demonstrated a striking effect of inhibiting blistering in organ culture of normal human skin with recessive dystrophic epidermolysis bullosa blister fluids. Subsequently we administered camostat mesylate by topical application to four patients with recessive dystrophic epidermolysis bullosa to assess its ability to reduce blistering. Therapeutic response was favorable; a significant effect in decreasing the number of blisters was observed in three of four patients. These findings actually supported the hypothesis that a kind of serine protease had a close relationship with blistering in recessive dystrophic epidermolysis bullosa and that therapy with a clinically usable protease inhibitor was useful for the treatment of this disease.

Administration, Topical↗
PubMed1988

Blood pressure control during eye surgery under local anesthesia. Actual status of blood pressure and experience with a new control method using intravenous nitroglycerin.

Blood pressure during eye surgery under local anesthesia was measured in 186 cases treated in our department. 58 cases showed an increase in blood pressure before the operation in spite of premedication; in 32 of these cases there was a 40% rise in blood pressure. Moreover, 38 cases showed at least one ECG abnormality just before the operation in spite of no past history of heart disorders. To control the blood pressure in these cases, intravenous injection of nitroglycerin (Millisrol) was performed continuously and immediately stabilized the blood pressure.

Anesthesia, Local↗
PubMed1987

Expression of anionic sites at the dermoepibolic junction.

The emergence of anionic sites during basement membrane zone formation was studied using migrating epidermis in organ culture as a model system. Ultrastructural investigations using a strongly cationized probe revealed that the heparitinase-sensitive, anionic sites were formed synchronously with the newly built basal lamina after 7 days in culture.

Basement Membrane↗
PubMed1987

In vitro damage of basal lamina-associated anionic sites by hydroxyl radical.

We examined the effect of chemically generated hydroxyl radical on basal lamina-associated anionic sites. Cytochemical studies showed that hydroxyl radical produced a loss of cationic tracer-positive, anionic particles, and this effect was inhibited by a specific scavenger, thiourea. These data might suggest that anionic sites were degraded by hydroxyl radical which was derived, for example, from the activated leukocytes in close contact with the dermal-epidermal junction during acute inflammation resulting in the disturbance of the charge-selective permeability barrier.

Anions↗
PubMed1987

Wavelength dependence of the geometric and structural photoisomerization of bilirubin bound to human serum albumin.

The two quantitatively important photoisomers in bilirubin metabolism during phototherapy are (ZE)-bilirubin and (EZ)-cyclobilirubin. We describe in vitro studies on the wavelength dependence for the geometric (delta 4Z, delta 15Z----delta 4Z, delta 15E) and structural (endovinyl cyclization) photoisomerization of bilirubin bound to human serum albumin by a high performance liquid chromatography method. For the geometric photoisomerization from (ZZ)-bilirubin to (ZE)-bilirubin, the most effective wavelength in vitro was 410 nm. For the structural photoisomerization, green light at 510 nm is the most efficient for causing cyclization of (ZZ)-bilirubin to (EZ)-cyclobilirubin via (EZ)-bilirubin and this may depend on a larger cross-section of (EZ)-bilirubin than (ZZ)-bilirubin in this spectral region and/or on a larger quantum yield for cyclization than geometric photoisomerization.

Bilirubin↗
PubMed1987

Wide distribution of rat hepatoma asialo GM1 and its different responses to anti-asialo GM1 antibody-mediated in vitro and in situ cell killing.

By means of TLC immunostaining with anti-asialo GM1 antiserum and conventional structural analyses including exoglycosidase treatment, permethylation and negative ion FABMS, asialo GM1 was found to be widely distributed in rat ascites hepatomas, AH130, AH109A, AH44, AH272, AH41C, AH60C, AH414, AH7974, AH66, AH66 alpha F, AH66F and AH13, and Yoshida sarcoma cells. However, reactivity of asialo GM1, when measured by flow cytometry and complement-mediated cytotoxicity assay with anti-asialo GM1 antiserum, was only observed on AH13 and AH66F, and did not necessarily correspond to the concentration of asialo GM1 on the cells, indicating a cryptic or unreactive nature of glycosphingolipids with respect to their antibodies. On the other hand, although rats injected with 10(7) cells of AH66F died within 7 days, treatment of the rats with anti-asialo GM1 antiserum was found to be effective for their cure or for prolonging their survival, indicating an in situ cytotoxic effect of antiserum. For the in situ cytotoxicity, the timing and period of injection and the dose of antiserum were found to be important.

Animals↗
PubMed1987

[Pharmacokinetic and clinical studies on cefotaxime in plastic and reconstructive surgery].

Pharmacokinetic and clinical studies on cefotaxime (CTX) in plastic and reconstructive surgery field were carried out. The results obtained are summarized as follows. Two grams of CTX was administered intravenously by single bolus injection to each of 4 patients with burn blisters and mean levels of CTX concentration in blister exudates were investigated. Thirty minutes after administration, the mean level of CTX in the exudates was 3.90 micrograms/ml and it reached a peak of 9.81 micrograms/ml in 2 hours. The clinical efficacy rate for 30 patients with burn infections and postoperative infections was 73.3%, and the efficacy rate for 29 patients in prophylactic use was 72.4%. A side effect (eruption) and abnormal laboratory findings were observed in each one case out of 59. From the above results, CTX may be considered to be useful in plastic and reconstructive surgical treatments.

Adolescent↗
PubMed1987

New substrate for determination of serum lecithin:cholesterol acyltransferase.

Serum lecithin:cholesterol acyltransferase (LCAT) was estimated by enzymatically measuring the decrease in unesterified cholesterol after incubation of serum with liposomes. A high-performance liquid chromatography (HPLC) study showed the uptake of the lipids of liposomes by serum high density lipoprotein. Of all the examined liposomes prepared from cholesterol and various synthetic phosphatidylcholines, liposomes with dimyristoylphosphatidylcholine (DMPC) were found to be the most reactive in the LCAT reaction. When serum was used as an enzyme source, addition of purified apolipoprotein A-I, which is known to be an endogenous activator of LCAT, to the assay mixture resulted in a slight decrease in enzyme activity. Using DMPC-cholesterol liposomes as the substrate, the LCAT activities in 120 human sera showed a mean value of 485.4 +/- 64.6 nmol/hr per ml (mean +/- SD), which is 4.4- to 5.4-fold higher than the values obtained by self-substrate methods. LCAT activity was a linear function of the serum sample volume up to 670 nmol/hr per ml and coefficients of variation (CV) less than 4% were obtained under the standardized conditions. Moreover, when partially purified LCAT was added to various heat-inactivated sera, the activity was efficiently recovered. These results suggest that this method is sensitive, reproducible, and not greatly influenced by serum components.

Cholesterol↗
PubMed1986

The effect of bilirubin photoisomers on unbound-bilirubin concentrations estimated by the peroxidase method.

Unbound bilirubin is oxidized to nearly colourless substances in the presence of H2O2 or ethyl hydroperoxide and horseradish peroxidase. To predict the risk of kernicterus (degenerated yellow pigmentation of nerve cells), this principle has been widely utilized for estimating the concentration of unbound bilirubin in hyperbilirubinaemic serum. However, the serum contains polar geometric photoisomers of bilirubin. Therefore, to clarify the effect of bilirubin photoisomer concentrations on unbound-bilirubin concentration, the concentration of bilirubin and its photoisomer and of unbound bilirubin in samples obtained from experiments in vivo and in vitro were simultaneously and individually estimated by h.p.l.c. and the peroxidase method. During photoirradiation, both in vivo and in vitro, the serum polar (ZE)-bilirubin IX alpha concentration increased remarkably, but unbound-bilirubin values were not affected at all. However, during experiments in vitro, unbound bilirubin concentrations increased only when concentrations of the rather polar (EZ)- and (EE)-cyclobilirubin IX alpha increased considerably in a human serum albumin-bilirubin solution irradiated with blue light. Thus it is concluded that unbound-bilirubin concentrations, and consequently the initial rate of the peroxidase reaction, is not accelerated by the increase in either (ZE)-bilirubin or (EZ)-cyclobilirubin concentration within the clinically observed range.

Bile Pigments↗
PubMed1986

Metabolism of bilirubin and its photoisomers in newborn infants during phototherapy.

Bilirubin and its photoisomers in the biological fluids of a hyperbilirubinaemic newborn infant before and during phototherapy were analyzed by a recently improved HPLC method. In the serum, the percentages of (EZ)- and (ZE)-bilirubin in the total bilirubin concentration before phototherapy were approximately 10% and on average increased over 1.5-fold at 2 h after initiation of phototherapy. The percentage of the (EZ)-cyclobilirubin in the serum bilirubin was under 1%. In the bile, the mean concentration of (ZZ)-bilirubin, derived mainly from (ZE)-bilirubin, nearly tripled during phototherapy. The (EZ)-cyclobilirubin concentration in the bile was very low before phototherapy, increased nearly ten-fold at 3 h after initiation of phototherapy, and was 5- to 6-fold as high as that of (ZZ)-bilirubin. In the urine, upon exposure to light, the urinary concentration of (EZ)-cyclobilirubin is apparently equivalent to half of the biliary concentration of (ZZ)-bilirubin and one-fifth of that of (EZ)-cyclobilirubin. It was concluded that during phototherapy of neonatal hyperbilirubinaemia the structural photoisomer [(EZ)-cyclobilirubin] predominates considerably over the geometric photoisomer [(ZE)-bilirubin].

Bilirubin↗
PubMed1986

Novel antibiotics napyradiomycins. Production, isolation, physico-chemical properties and biological activity.

Novel antibacterial antibiotics napyradiomycins A, B1, B2, B3, C1 and C2 have been isolated from the culture broth of Chainia rubra MG802-AF1. In this paper, taxonomy of the producer, and production, isolation, physico-chemical properties and biological activities of napyradiomycins are reported. They contain the naphtopyran chromophore and halogens, and inhibit the growth of Gram-positive bacteria including drug-resistant strains.

Animals↗