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Biomedical subjects

R Matsuo

Publications and source records attributed to R Matsuo.

At least 91 records · Page 5Linked to original sources
PubMed1988

Approach to maceration mechanism in enzymatic pulping of bast fibers by alkalophilic pectinolytic enzymes produced by Erwinia species.

Tissue maceration was generally elucidated by the action of endo-polygalacturonase and endo-pectate or -pectin lyase (endo-PAL or -PNL). In a process of screening of Erwinia and Pseudomonas strains for enzymatic pulping of pectocellulosic bast fibers, it was found that their PAL productivity was not completely related with defibration activity, i.e., the fact that an E.chrysanthemi strain showed high PAL productivity but possessed rather low defibration activity. Moreover, defibration activity was parallel to the amount of neutral sugars released during pulping. Based on these fact, the maceration or enzymatic pulping of basts was estimated to proceed not only by cleavage of interfiber bonding cause by PAL action but also another factors. Among three possibilities proposed on the maceration mechanism of basts, it was elucidated by a concerted action of PAL and PNL with an aid of xylanase. In addition, a quantitative determinative method of maceration activity toward basts was also presented.

Journal Article↗
PubMed1988

Sensory inputs from the oral region to the cerebral cortex in behaving rats: an analysis of unit responses in cortical somatosensory and taste areas during ingestive behavior.

1. The responses of 90 cortical neurons in the somatosensory and gustatory areas were recorded with chronically implanted fine wires in freely moving Wistar rats. The responses were analyzed mainly while the animals were freely licking solutions and eating dry pellets. Cortical neurons were classified into several groups according to their response properties. 2. "Mechanosensitive" neurons (n = 20) showed rhythmic phasic activity in different phases of the licking cycle, depending on the location of their receptive field in the peripheral orofacial region. 3. "Movement-related" neurons (n = 27) changed their activities tonically during licking, chewing, or grooming behavior. The responses were either excitatory or inhibitory. Receptive fields and adequate stimuli could not be identified. These neurons might receive somatosensory (except light tactile) inputs from wide or deep areas of intra- or perioral regions, or might be related to orofacial active movement. 4. "Taste" neurons (n = 35) increased or decreased their discharge rates during licking of particular taste solutions. Some taste neurons received convergence from somatosensory inputs. 5. "Temperature" neurons (n = 2) responded exclusively to water of temperatures lower or higher than room temperature. The responses were opposite in direction between cold and warm stimuli. 6. "Anticipation" neurons (n = 4) increased their impulse discharges before the start of licking in the situation in which the animal expected access to the drinking tube. 7. "Attention" neurons (n = 2) responded to arousal stimulation such as sound, a flash of light, and body touch. These neurons showed only a slightly increasing response during ingestive behavior. 8. The locations of 56 of 90 units were histologically identified. Mechanosensitive neurons were located in the appropriate parts of the somatotopic pattern within the primary somatic sensory area in the granular cortex. Taste neurons were found evenly in the dysgranular cortex and the agranular insular cortex. Other types of neurons were located mainly in the dysgranular cortex between the granular cortex and agranular insular cortex, and some were intermingled with taste neurons in the agranular insular cortex. 9. The present study has shown that cortical neurons in the orolingual somatosensory and taste areas have different response characteristics related to each aspect of ingestive behavior.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1988

[Experimental and clinical studies on degradable starch microspheres (DSM) in the treatment of hepatic neoplasms].

To evaluate the effect of hepatic arterial chemotherapy combined with DSM, experimental and clinical studies were performed. Experimental study: Hemodynamic and histological changes induced by intra-arterial administration of DSM were investigated in the kidneys of rabbits. The degree of blockade of arterial blood flow was correlated with the dosage of DSM, and estimated by the angiographic change. Histological changes also depended on the dosage of DSM. Although administration of less than 6 mg DSM induced little or no histological changes, more than 15 mg of DSM induced extensive necrosis of renal tubules. Clinical study: The hepatic arterial chemotherapy combined with DSM was performed in 63 patients (hepatomas in 45 and metastatic tumors in 18). Fourteen patients (30%) showed partial or complete response. Patients with a higher degree of blockade of arterial blood flow tended to have a better response. Analysis of CT images suggested that DSM not only enhance the chemotherapeutic agents but also the ischemic effect. In conclusion, degree of blockade of arterial blood flow is controlled by the change in DSM dosage, and DSM administration combined with chemotherapeutic agents may have the potential to improve the therapeutic effect.

Animals↗
PubMed1987

Appearance of frontal mid-line theta rhythm during sleep and its relation to mental activity.

Fm theta occurred not only during mental tests in the waking state but also during nocturnal sleep in which it was most frequent during REM and secondarily most frequent during stage 1 of NREM sleep. As for the inner experience of the subjects, they frequently reported dream and distinct mentations on awakening from REM sleep whether or not it was accompanied by Fm theta. They reported dream and distinct mentations more frequently when awakened from stage 1 of NREM sleep with Fm theta than when awakened from stage 1 of NREM sleep without Fm theta. Relationship of Fm theta to mental activity during sleep was briefly discussed.

Adolescent↗
PubMed1986

Effect of body temperature on salivary reflexes in rats.

Salivary secretion was evoked reflexly by taste or noxious stimulation at different body temperatures in urethane anesthetized rats. Magnitude of salivary secretion induced either by a taste stimulus or by a pinch was facilitated by increasing rectal temperature in a range of 39-40.3 degrees C. Above a threshold rectal temperature of 40.4 degrees C, copious saliva was continuously secreted without external stimulation.

Animals↗
PubMed1985

Gustatory reaction time to various sweeteners in human adults.

Reaction times to recognize the sweet taste of 12 sweeteners at various concentrations were measured in 48 human adults. The reaction time (T) decreased with increasing concentration (C) of each sweetener applied to the anterior dorsal tongue. The relationships between T and C, and T and logC were well described by a rectangular hyperbola formula for each of the 12 sweeteners. Reaction times to discriminate sweet taste quality between pairs of sweeteners were measured, then a similarity index was calculated. Factor analysis based on correlation coefficients between pairs of sweeteners which were obtained by the similarity indices has indicated classification of the sweeteners. Sucrose, fructose, glucose, maltose, sorbitol and aspartame tend to group together. Na-cyclamate and Na-saccharin form another group. DL-alanine, stevioside and neohesperidin dihydrochalcone are rather independent and do not belong to any group.

Adult↗
PubMed1985

[Clinical experience with cefmenoxime (CMX) in complicated urinary tract infections].

Cefmenoxime (CMX) was intravenously administered to 106 patients with complicated urinary tract infection at a daily dose of 2-4 g for 5 days. An excellent response in overall clinical efficacy was seen in 15 cases (18.3%), a moderate response in 46 cases (56.1%) and poor response in 21 cases (25.6%). Pyuria was cleared in 20 cases (24.4%), decreased in 22 cases (26.8%) and unchanged in 40 cases (48.8%). Bacteriuria was eliminated in 41 cases (50.0%), decreased in 17 cases (20.7%), relapsed in 7 cases (8.5%) and unchanged in 17 cases (20.7%). Bacteriologically, 74 (76.8%) of the 95 strains isolated were eradicated by CMX, and 22 (23.2%) persisted. Side effects were observed in 3 (abdominal pain, diarrhea and elevation of trans amylase) of the 106 cases. Judging from the above results, CMX is considered to be a useful drug in the treatment of complicated urinary tract infections.

Adolescent↗
PubMed1984

Lateral hypothalamic modulation of oral sensory afferent activity in nucleus tractus solitarius neurons of rats.

This study was designed to examine whether the sensory afferents from the anterior part of the tongue are modulated by activity of the lateral hypothalamic area (LHA) at the level of the nucleus tractus solitarius (NTS) in rats. The electrical activity of the NTS neurons was recorded extracellularly, and they were classified as gustatory, thermal, or mechanical neurons in accordance with their responsiveness to tongue stimulation by taste solutions, by warm and cool water, and by stroking the tongue surface. Sixty-two percent of the neurons were polysynaptically activated by electrical stimulation of the LHA. When a single conditioning stimulus of the LHA was applied prior to the test electrical stimulation of the tongue at various conditioning-test intervals, the activity of the gustatory neurons was facilitated by 30 to 80% of their control level for a period of approximately 20 to 150 msec. The activity of the mechanical and thermal neurons was suppressed for a 50- to 300-msec period. These results demonstrate the existence of modulatory effects from the LHA on the NTS neurons, which receive sensory information from the tongue.

Afferent Pathways↗
PubMed1984

Lateral hypothalamic modulation of the gustatory-salivary reflex in rats.

It is well recognized that the basic mechanism for the gustatory-salivary reflex is located in the lower brainstem and that suprabulbar structures possibly influence this mechanism. This study is designed to evaluate the neurophysiological mechanism underlying the effect of the lateral hypothalamic area (LHA) on the bulbar gustatory-salivary reflex. Submandibular salivary secretion and the electrical activity of the preganglionic parasympathetic fibers innervating the submandibular and sublingual glands were recorded in anesthetized rats. Stimulation of the tongue with high concentrations of chemical solutions (1 M and 2 M NaCl and 0.01 M and 0.05 M HCl) and/or pinching the tongue with a small clamp induced a profuse salivary secretion (3 to 28.5 microliter/5 min) recorded from a unilateral submandibular gland. The preganglionic fibers consisted of three types: taste-related fibers, which increased their firing rate by taste stimuli; pinch-related fibers, which increased their firing rate by pinching; and unidentified fibers, which did not respond to taste or pinching stimulations of the tongue. Electrical stimulation of the ipsilateral LHA caused the secretion of a small amount of saliva (1.5 microliter/5 min), and it appeared that taste-related fibers more often received polysynaptic connections from the LHA than other types of fibers. Conditioning stimulation of the LHA increased the magnitude of impulse discharges by the test stimulation of the tongue in the taste-related fibers. Therefore, the results of this study demonstrate that the LHA enhances the activity of the gustatory-salivary reflex in the lower brainstem.

Animals↗
PubMed1982

Antibodies to adult T-cell leukemia-virus-associated antigen (ATLA) in sera from patients with ATL and controls in Japan: a nation-wide sero-epidemiologic study.

A nation-wide sero-epidemiologic survey of adult T-cell leukemia virus (ATLV), detected es anti-ATLA (ATLV-associated antigen), was made in Japan. Sera from adult donors in 15 different locations were screened for anti-ATLA. High incidences (6 to 37%) of antibody-positive donors were found in seven regions, one in northern Japan, and the others in southwestern regions. These areas are ATLV-endemic areas corresponding to ATL-endemic areas. Examination of sera from healthy donors aged 6 to 80 years in ATL-endemic areas showed an age-dependent increase of seropositive donors with a maximum of about 30% at 40 years of age. Anti-ATLA was found in all but two of 142 patients with ATL. Anti-ATLA-positive patients with ATL were mainly found in ATLV-endemic areas, and only a few in ATL-nonendemic areas. Six patients with cutaneous T-cell lymphoma in ATLV-nonendemic areas gave a negative reaction for anti-ATLA. The geometric mean titer of anti-ATLA of patients with ATL was higher than that of healthy donors.

Adult↗
PubMed1982

Hypoglossal motor nerve activity elicited by taste and thermal stimuli applied to the tongue in rats.

Single unit activity of hypoglossal motor nerve fibers which innervate the tongue muscles was recorded in lightly anesthetized non-decerebrate and acute decerebrate rats. The pattern of responses to taste and thermal stimuli applied to the tongue surface was classified into 4 types. The type 1 response is characterized by short-lasting rhythmic burst discharges, the type 2 consists of both the rhythmic burst and tonic discharges, the type 3 is long-lasting tonic discharges and the type 4 shows short-lasting burst or short-lasting tonic discharges. In non-decerebrate rats, most of the fibers (93%) showed no or a few spontaneous firings. Sucrose and NaCl were the most effective stimulants, and 70-80% of the fibers showed the type 1 response to these stimuli, sucrose and NaCl, and HCl and quinine produced a similar response profile, respectively. In decerebrate rats, however, about 21% of fibers showed a highly regular spontaneous firing (about 30 Hz). Rhythmic burst responses (types 1 and 2) were not induced, and thermal (especially cold) stimulation elicited much better responses than the taste stimuli. HCl and quinine, but not sucrose and NaCl, produced a similar response profile. These characteristic properties of the response in acute decerebrate rats may in part be attributed to inactivation of a 'rhythmic center' in the brain stem.

Animals↗
PubMed1982

EMG activities of masticatory muscles during licking in rats.

EMG activities of the jaw closers and the jaw opener were recorded during licking of water and varying taste solutions in rats. The rats showed a continuous and rhythmic licking pattern (about 7 Hz) when they took water, 0.5 M sucrose and 0.1 M NaCl. A clear reciprocal relation of the jaw closers and opener was recognized during licking. The digastric muscle (jaw opener) started to work about 60 msec before the contact of the tongue with the liquid and ceased its activity at the moment of the contact, while the temporalis and masseter muscles (jaw closers) started to work about 50 msec after the contact. On the other hand, the rats rejected 1 M NaCl and 5 X 10(-4) M quinine-HCl, and stopped licking within a few seconds. However, EMG activities of the masticatory muscles continued more than 20 sec after cessation of licking. A characteristic jaw opening (gaping) was observed after licking quinine or after an oral infusion of 0.3 M CaCl2. To presentations of 0.03 M HCl and 0.3 M NaCl, the licking pattern was the intermediate between the above-mentioned licking patterns shown by acceptable and rejective taste stimuli, i.e., the rats tended to show intermittent lickings to these HCl and NaCl solutions and the interlick interval varied greatly. The present results suggested that licking patterns and EMG activities of the masticatory muscles were characterized by the hedonic aspect or palatability of taste (acceptance-rejection dichotomy) rather than the taste quality (whether a taste is sugar, salt, acid, etc.).

Animals↗
PubMed1982

Gustatory reaction time under variable stimulus parameters in human adults.

Reaction times and perceived intensities for NaCl solutions were measured in sixteen human adults. Stimulus delivery was by means of a circular piece of solution-soaked filter paper held with forceps. The reaction time (T) decreased and the perceived intensity (S) increased with increasing the concentration (C) of NaCl solution applied to a fixed (78.5 mm2) tongue area. The comprehensive relations among T, S and C can be expressed by the following formula; T=a+b/log(C/Co), T=p+q/log(S/So), and logS=mlogC+logn, where a, b, p, q, m, n=constants, and So indicates the perceived intensity at the threshold concentration (Co). Meanwhile, the reaction time decreased and the perceived intensity increased with increasing the stimulated area (A) under a fixed (1.0 M) concentration of NaCl solution. The relations among T, S and A can also be expressed by the following equations; T=a'+b'/log(A/Ao), T=p'+q'/log(S/So), and logS=m'logA+logn', where a', b', p', q', m', n'=constants, and Ao indicates the threshold size of stimulated area.

Adult↗
PubMed1982

Analysis of reflex responses in preganglionic parasympathetic fibres innervating submandibular glands of rabbits.

1. The volume of submandibular salivary secretion and electrical activities in preganglionic parasympathetic fibres innervating the submandibular gland were recorded in rabbits, anaesthetized with chloralose-urethane, to evaluate the neural control mechanisms subserving reflex salivary secretion. 2. Single, paired or repetitive electrical shocks were applied to the various parts of the oral region in sympathetically decentralized animals. A copious salivary secretion was induced when the repetitive electrical stimulation was applied to anterior ipsilateral parts of the oral region, especially the upper lip. The optimum frequency of stimulation was 10--20 Hz. 3. About 90% of the preganglionic parasympathetic fibres responded to single electrical shock applied to a respective confined area of the oral region with a mean latency of 10.8 msec. The remainder responded to wider areas of the oral region with a mean latency of 31.5 msec. 4. Preganglionic fibres were classified into three types (E-type, N-type and I-type) in accordance with the mode of impulse discharges. Spontaneous discharges of E-type fibres (41%) were increased, while those of N-type fibres (36%) were unchanged and those of I-type fibres (23%) were decreased by repetitive stimulation at over 10 Hz. Most dominant responses in E-type fibres were induced by electrical shocks with a frequency of 10--20 Hz. 5. When paired shocks with varying intershock intervals were applied, excitability of E-type fibres was enhanced for about 20 msec, and then inhibited for about 100 msec, while that of N-type was inhibited for 150--200 msec, and I-type was inhibited for 500--700 msec after onset of the first shock. 6. The volume of reflex submandibular salivation evoked by varying frequencies of electrical shocks applied to the oral region correlated statistically significantly with the magnitude of responses in E-type fibres. This result strongly suggests that E-type fibres are secretory fibres. The functional significance of N-type and I-type fibres is discussed.

Action Potentials↗