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Biomedical subjects

H Kamei

Publications and source records attributed to H Kamei.

At least 181 records · Page 10Linked to original sources
PubMed1982

Interlimb coordination in cat locomotion investigated with perturbation. I. Behavioral and electromyographic study on symmetric limbs of decerebrate and awake walking cats.

During locomotion of decerebrate and awake walking cats, perturbation (mechanical tap) was applied to the paw dorsum of the left forelimb (LF), and the responses of both forelimbs were recorded cinematographically and electromyographically (EMG). When the tap was applied during the LF stance phase, the duration of the ongoing LF stance was shortened by 10%; in the right forelimb (RF), the duration of the concomitant swing was shortened by 32%. A tap during the LF swing phase prolonged the duration of the ongoing LF swing phase and the concomitant RF stance phase by 55 and 15%, respectively. Analysis of RF joint angle excursions showed that the shortening of the RF swing phase was related mainly to acceleration of extension movement in the late swing phase; the prolongation of the RF stance phase was related to prolonged extension movement in the late stance phase. While EMG activities were relevant to these limb movements, a notable observation was that, by tapping the LF during the LF stance phase, EMG activity in the RF extensor started well before onset of the elbow extension movement to place down the limb; without the tap, the extensor activity started shortly after onset of the extension. Closely related to changes in phase durations of each forelimb, the period of bisupport phase where both forelimbs were in stance, was retained for more than 40% of that of unperturbed steps, even when the RF or LF made the first touchdown after the tap. The rostrocaudal level at RF touchdown after the tap was comparable to unperturbed steps. These findings on interlimb relation suggest that neural control ensures coordinated movements between symmetric limbs during locomotion.

Animals↗
PubMed1982

Interlimb coordination in cat locomotion investigated with perturbation. II. Correlates in neuronal activity of Deiter's cells of decerebrate walking cats.

The effects of mechanical stimulation (tap) on single unit activity of Deiter's neurons were analysed in walking cats decerebrated at the premammillary level. Deiters' neurons projecting to the ipsilateral cervical, but not to the lumbosacral, spinal cord (C-Deiters' neurons) were identified by antidromic activation, cerebellar stimulation, and localization of the neurons. During each unperturbed cycle of quadrupedal locomotion, most C-Deiters' neurons showed two frequency modulation peaks in their impulse discharges: one (A peak) in the late swing (E1) or the early stance (E2) phase, the other (B peak) in the late stance (E3) or the early swing (F) phase, of the ipsilateral forelimb. The A peak started to rise shortly before the ipsilateral forelimb was placed. When mechanical perturbation was applied during locomotion to the paw dorsum of the left forelimb (LF) in its stance phase, the ongoing LF stance phase shortened and the simultaneous swing phase of the right forelimb (RF) shortened. Accordingly, in the RF, extensor activity in the swing phase to place down the limb occurred earlier than in unperturbed step cycles. The same LF tap induced a marked enhancement of impulse discharges in C-Deiters' neurons on the right side (with a magnitude of 20-100 imp/s, and the shortest latency of 25 ms). This enhancement was more pronounced than that induced when the perturbation was applied to the LF during its swing phase. The latency manifested a close time relation to the RF extensor activity supporting the postulate that the increased C-Deiters' activity in the RF swing phase contributes to the earlier onset of RF extensor activity which plays an important role in maintaining alternating footfalls after perturbation.

Animals↗
PubMed1982

Differential effector functions of central and peripheral compartments of immune response system: characterization of immune responses in the spleen and mesenteric lymph nodes to directly injected sheep red blood cells.

When sheep red blood cells (SRBC) were injected intraperitoneally (i.p.), intravenously (i.v.), or into the Peyer's patches, definite plaque-forming cell (PFC) and rosette-forming cell (RFC) responses were induced in the spleen but not in the mesenteric lymph nodes (MLN). When SRBC were injected directly into the spleen or MLN, stronger PFC and RFC responses were induced in the spleen or MLN, respectively, than when injected i.p. or i.v. PFC response induced in MLN by injecting SRBC into MLN with or without the polysaccharide of Klebsiella pneumoniae type 1 Kasuya strain (CPS-K) as an immunological adjuvant was weaker than that induced in the spleen by injecting the antigen into the spleen. Direct PFC (PFC of IgM type) and RFC responses induced in the spleen by injecting SRBC into MLN were rather stronger than those induced in the spleen by injecting the antigen into the spleen. In contrast, no significant responses were induced in MLN by injecting SRBC into the spleen, and no definite indirect PFC (PFC of IgG type) response was induced in the spleen by injecting the antigen into MLN. The levels of whole immunological memory as well as isolated B- or T-cell memory in the spleen and MLN of mice injected with SRBC directly into the spleen or MLN were determined by using an in vitro assay system. Definite amounts of either B- or T-cell memory were detected in the spleen of mice injected with SRBC directly into the spleen of MLN. Smaller amounts of memory were detected in MLN injected with SRBC directly into the spleen. Moreover, the amounts of whole memory detected in MLN were much less than compared with those of isolated T- and B-cell memories in MLN. Further experiments showed that in vitro expression of the memories preserved in MLN required supplement of glass non-adherent cells from normal spleen. Based on these results, we discussed the possible differential and collaborative functions of the central (spleen) and peripheral (MLN) immune response systems in antibody responses.

Animals↗
PubMed1982

Anti-asthmatic activity of BB-1502 by inhalation.

The anti-asthmatic activity, pulmonary mechanics and cardiovascular effects of BB-1502 (9-cyclohexyl-2-n-propoxy-9H-adenine) administered by aerosol were evaluated in guinea pigs and dogs and compared with the effects of salbutamol. BB-1502 protected guinea pigs from allergic asthma induced by aerosolized egg albumin antigen. The potency of BB-1502 was approx. 1/7 that of salbutamol when the test drugs and antigen were aerosolized simultaneously, whereas the two drugs were equipotent when administered 60 min prior to the antigen challenge. The duration of the anti-asthmatic action of BB-1502 appeared to be much longer than that of salbutamol. In dogs, BB-1502 and salbutamol showed comparable activity in preventing ascaris antigen-induced asthmatic symptoms. Disodium cromoglycate showed anti-asthmatic activity at high doses while aminophylline was inactive by inhalation. No cardiopulmonary side effects were observed in guinea pigs or dogs following the inhalation of BB-1502. The doses were 800-5,000 times higher than those needed to produce the anti-asthmatic activity. Salbutamol caused significant tachycardia, hypotension and tachypnea at doses 100-300 times its anti-asthmatic dose.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1982

Effect of angiotensin converting enzyme inhibitor on serum aldosterone and potassium level.

An angiotensin converting enzyme inhibitory, captopril (or SQ 14225), was administered orally to 23 hypertensive patients under a constant sodium and potassium diet. It resulted in reduction of plasma aldosterone concentration which was related significantly to the increase of serum potassium level (r = -0.533), but only weakly to the reduction of plasma angiotensin II level (r = 0.474). Aldosterone level remained suppressed in the face of increased serum potassium. The effects on aldosterone level and potassium were greater in patients with high plasma renin activity than in those with low and normal plasma renin activities. They also paralleled the reduction in blood pressure. It is suggested that reduction in aldosterone level and potassium retention were caused by blockade of angiotensin II formation by captopril, but the potassium retention was additionally influenced by renal impairment.

Adult↗
PubMed1982

High renin low blood pressure and its treatment with calcium glycyrrhetinyl-glycinate.

Elevated plasma renin activity was found in 6 out of 7 essential hypotensive patients. This was taken to reflect some abnormality in sodium handling, and they were treated with synthetic calcium glycyrrhetinyl-glycinate (G.G.), a water soluble derivative of glycyrrhetinic acid which was derived from licorice. G.G. was administrated in doses of 300 mg to 1200 mg daily for 3 to 9 weeks. Both the systolic (25.8 +/- 10.0 mmHg) and diastolic (19.2 +/- 9.8 mmHg) blood pressure successfully elevated and improvement or resolution of clinical symptoms was noted in 6 patients. Marked suppression in plasma renin activity (2.7 +/- 1.2 ng/ml/hr) and plasma aldosterone concentration (8.1 +/- 3.1 ng/100 ml) with mild reduction in serum potassium concentration (1.0 +/- 0.4 mEq/L) were concomitantly observed. One patient did not respond at all to G.G. Adverse reactions were mild in all but one who had frank edema.

Adult↗
PubMed1982

A case of pseudoaldosteronism due to addiction of Jintan, a mouth refresher popular among Japanese.

A 50-year-old man with hypertension showed hypokalemia, hyporesponsive low reninemia, and low levels of aldosterone in the plasma and urine. Plasma DOC and corticosterone level, adrenal scintigram, and phlebogram were within normal limits. Hypertension and hypokalemia were correctable by spironolactone. It was revealed that he had been ingesting Jintan granules in large doses, corresponding to 150-220 mg of glycyrrhizic acid per day for 10 years. Upon cessation of Jintan ingestion, blood pressure and serum potassium level were normalized after 40 days. Metabolic alkalosis, hypervolemia, hyporesponsive low reninemia, and the low levels of plasma and urine aldosterone were also improved. Thus, the present case of pseudoaldosteronism was attributed to Jintan, and raises a caution to excessive Jintan ingestion.

Captopril↗
PubMed1981

Simple and complex spike activities of Purkinje cells during locomotion in the cerebellar vermal zones of decerebrate cats.

In walking cats decerebrated at the premammillary level, single neurone activity of Purkinje cells (P-cells) with long corticofugal axons was recorded in the cerebellar vermis. The P-cells (N = 145) were identified as they showed spontaneous simple and complex spikes and also antidromic activation from Deiters' nucleus. These P-cells were classified into 6 groups according to the receptive fields of the climbing fibre responses (CFRs) which were evoked by electrical stimulation in each limb at the radial and sciatic nerve bundles. One group designated as forelimb units received the CFRs from both forelimbs and from neither hindlimb. According to previous studies, this group of P-cells is thought to make inhibitory connections with Deiters neurones projecting to the ipsilateral cervicothoracic spinal cord. For the forelimb units, two types of discharge patterns for simple spikes were found in relation to limb movements during locomotion. Type I cells showed one peak in their firing rate in the late swing (E1) or early stance (E2) phase of the ipsilateral forelimb. Type II cells showed two peaks and two valleys during one step cycle: one peak was in the E1 phase, the other in the late stance (E3) or early swing (F) phase; each of the two valleys followed the peak. Complex spikes of the forelimb units occurred more frequently in the E1 phase than during the other phases. The increased activity of simple and complex spikes of the forelimb units in the E2 phase is suggested to have a functional significance in preparing the appropriate floor reaction forces that appear upon touchdown on the ipsilateral forelimb.

Animals↗
PubMed1981

Mitotic index in gastric carcinoma of the scirrhous type.

For the purpose of studying the clinical and pathological specificities of the scirrhous type in gastric carcinoma, 96 patients with gastric carcinoma were studied according to age, sex, stage, macroscopic types and mitotic index. Scirrhous carcinoma was diagnosed in 45 patients. There were higher incidences of scirrhous carcinoma in the younger generation and among women. In the scirrhous type, the percentage of stages III and IV was higher than that of stages I and II (p less than 0.005). In Borrmann's categories III and IV, patients with the scirrhous type were more numerous than those with the other types. Mitotic indices were 18.4 +/- 8.1 in scirrhous type, 52.8 +/- 13.5 in medullary type, 54.1 +/- 16.9 in intermediate type and 53.3 +/- 11.5 in non-cancerous gastric mucosa. The low rate of mitotic index in those with scirrhous carcinoma was statistically significant compared to those of other types and that of the non-cancerous gastric mucosa (P less than 0.001). Mitotic index is apparently related to the extent and the degree of degeneration of interstitial connective tissue. The speed of the growth of the tumor mass in gastric carcinoma is not so closely related to the mitotic index, and relates to a greater extent the number of dissociated cells entering the digestive canal.

Adenocarcinoma↗
PubMed1981

Pharmacological studies on BB-1502, a new bronchodilator.

The pharmacological activities of BB-1502 (9-cyclohexyl-2-n-propoxy-9H-adenine), a potent bronchodilator and inhibitor of cyclic AMP phosphodiesterase, were compared with those of aminophylline in a number of biological systems. IOn vitro, BB-1502 relaxed guinea pig tracheal tissue at a concentration ca. 600 times lower than that required for aminophylline. The ability of BB-1502 to inhibit cyclic AMP phosphodiesterase of guinea pig lung origin was 15 times greater than that of aminophylline. The direct bronchodilator activity of BB-1502 determined in guinea pigs by the intraduodenal route was 5 times greater and the duration of the action longer than that of aminophylline. In dogs, intraduodenal BB-1502 inhibited bronchoconstriction induced by pilocarpine, histamine, or acetylcholine and the activity of the new compound was 4 to 7 times more potent than that of aminophylline. In experimental asthma studies, orally administered BB-1502 protected guinea pigs from allergy-induced asthma provoked by an antigen challenge with aerosolized egg albumin and here the potency was 4 times greater that that of aminophylline. Ascaris antigen-induced asthma in dogs was completely inhibited by the oral administration of BB-1502 in a dose of 1 mg/kg with significant protection seen at 0.3 and 0.1 mg/kg. No complete protection was obtained with aminophylline in the dog asthma model. Cardiovascular effects observed with guinea pigs and dogs following the oral administration of BB-1502 were considerably less than those seen with aminophylline. CNS side effects were nil in rats when BB-1502 was given at 3 times the dose that produced significant stimulation by aminophylline. Acute lethal toxicity determined in mice by the oral route was similar for BB-1502 and aminophylline.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1981

Effect of alternating administration of PS-K and carbazilquinone in tumor-bearing mice.

In order to establish procedure for immunochemotherapy, the delayed hypersensitivity reaction (DHR) was investigated in tumor-bearing mice treated with an immunopotentiator, basidiomycetes polysaccharide (PS-K). DHR in the group given continuous administration of immunopotentiator was initially much stronger than that in the untreated group; however, the reactions were the same by the 4th week. The tumor-bearing group give intermittent administration of immunopotentiator retained strong DHR throughout the course, even though prolonged continuous administration failed to maintain such elevated immunoresponses. Alternating treatment with PS-K and carbazilquinone induced much higher DHR and much longer survival. The experimental results showed that continuous administration of an immunopotentiator led to decreasing immune responses in tumor-bearing mice. Intermittent administration of immunopotentiator was proved to be effective in restoring tumor suppression.

Adjuvants, Immunologic↗
PubMed1980

Effect of carcinogenic polycyclic aromatic hydrocarbons on mouse embryonic cells in culture: induction of spindle-shaped cells.

In cultured mouse embryonic cells (MECs) treated with benzo[a]pyrene (B[a]P), there appeared unusual type of fibroblasts, spindle-shaped cells (SP cells), which were characterized by their narrow bipolar shape, long cellular processes and optically distinct cell borders. Appearance of SP cells was massive and irreversible. The amount of SP cells increased with increasing concentrations of B[a]P, while early cytotoxicity did not. In various polycyclic aromatic hydrocarbons (PAHs) tested, only potent carcinogens (7,12-dimethylbenz[a]anthracene (DMBA), 3-methylcholanthrene (MCA), B[a]P, and dibenz[a,e]pyrene (DB[a,e]P) induced SP cells. Among them, PAH having higher Iball's index induced SP cells at lower concentration and at an earlier time. Weak or non-carcinogenic PAHs including 3-hydroxybenzo[a]-pyrene (3-OH-B[a]P) did not induce SP cells. alpha-Napthoflavon (alpha NF) suppressed the induction of SP cell by carcinogenic PAH. SP cells did not appear spontaneously under various abnormal culture conditions. These results indicate that carcinogenic PAHs induce the appearance of a specific type of fibroblast, SP cells in MEC cultures in accordance with their carcinogenicity.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1980

[Mechanism of action of certain fibrinolytic bis-tetrahydroisoquinolines: their antagonists and histamine- and 5-hydroxytryptamine-releasing effects (author's transl)].

1, 1'-Heptamethylene-bis-6, 7-dimethoxy-1, 2, 3, 4-tetrahydroisoquinoline (HBDT) and 1, 1'-tetramethylene-bis-6, 7-dimethoxy-1, 2, 3, 4-tetrahydroisoquinoline (bisobrin) produced an edema when given subcutaneously into the hind paws of rats. The inhibitory effects of various antagonists on the paw edema and fibrinolysis induced by HBDT were examined in rats to determine whether chemical mediators other than histamine were involved. The relation of histamine to the fibrinolytic activity of these bis-tetrahydroisoquinoline derivatives has already been reported. Both edema and fibrinolysis were significantly inhibited by pretreatment with promethazine, cyproheptadine or phentolamine, but not by dibenamine, propranolol, atropine, indomethacin or pyridinolcarbamate. epsilon-Aminocaproic acid inhibited the fibrinolytic activity completely without any effect on the paw edema. HBDT released 5-hydroxytryptamine (5-HT) along with histamine from rat peritoneal mast cells. However, the amount of released 5-HT was considerably smaller than that of histamine. These results suggested that bis-tetrahydroisoquinolines released both histamine and 5-HT and that these mediators produced paw edema and induced fibrinolysis by enhancement of plasmin production.

Animals↗