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C Chiba

Publications and source records attributed to C Chiba.

18 recordsLinked to original sources
PubMed1992

Glutamatergic motoneurons in the stomatogastric ganglion of the mantis shrimp Squilla oratoria.

1. Transmitters of motoneurons in the stomatogastric ganglion (STG) of Squilla were identified by analyzing the excitatory neuromuscular properties of muscles in the posterior cardiac plate (pcp) and pyloric regions. 2. Bath and iontophoretic applications of glutamate produce depolarizations in these muscles. The pharmacological experiments and desensitization of the junctional receptors elucidate the glutamatergic nature of the excitatory junctional potentials (EJPs) evoked in the constrictor and dilator muscles. The reversal potentials for the excitatory junctional current (EJC) and for the glutamate-induced current are almost the same. 3. Some types of dilator muscle show sensitivity to both glutamate and acetylcholine (ACh) exogenously applied. The pharmacological evidence and desensitization of the junctional receptors indicate the glutamatergic nature of neuromuscular junctions in these dually sensitive muscles. The reversal potentials for the EJC and for the ACh-induced current are not identical. 4. Glutamate is a candidate as an excitatory neuro-transmitter at the neuromuscular junctions which the STG motoneurons named PCP, PY, PD, LA and VC make with the identified muscles. Kainic and quisqualic acids which act on glutamate receptors are potent excitants of these muscles. Extrajunctional receptors to ACh are present in two types of the muscle innervated by LA and VC. 5. Neurotransmitters used by the STG motoneurons of stomatopods are compared to those of decapods.

Acetylcholine↗
PubMed1991

Mechanisms underlying burst generation of the pyloric muscle in the mantis shrimp, Squilla oratoria.

The pyloric constrictor muscles of the stomach in Squilla can generate spikes by synaptic activation via the motor nerve from the stomatogastric ganglion. Spikes are followed by slow depolarizing afterpotentials (DAPs) which lead to sustained depolarization during a burst of spikes. 1. The frequency of rhythmic bursts induced by continuous depolarization is membrane voltage-dependent. A brief depolarizing or hyperpolarizing pulse can trigger or terminate bursts, respectively, in a threshold-dependent manner. 2. The conductance increases during the DAP response. The amplitude of DAP decreases by imposed depolarization, whereas it increases by hyperpolarization. DAPs from successive spikes sum to produce a sustained depolarizing potential capable of firing a burst. 3. The spike and DAP are reduced in amplitude by decreasing [Ca]o, enhanced by Sr2+ or Ba2+ substituted for Ca2+, and blocked by Co2+ or Mn2+. DAPs are selectively blocked by Ni2+, and the spike is followed by a hyperpolarizing afterpotential. 4. The spike and DAP are prolonged by intracellular injection of the Ca2+ chelator EGTA. A hyperpolarizing afterpotential is abolished by EGTA and enhanced by increasing [Ca]o. The DAP is diminished in Na(+)-free saline and reduced by tetrodotoxin. 5. It is concluded that the muscle fiber is endowed with endogenous oscillatory properties and that the oscillatory membrane events result from changes of a voltage- and time-dependent conductance to Ca2+ and Na+ and a Ca2+ activated conductance to K+.

Animals↗
PubMed1990

Social preference of female gerbils (Meriones unguiculatus) as influenced by coat color of males.

Female gerbils (Meriones unguiculatus) of three distinct coat colors (agouti, black, and sandy or pink-eyed dilution) were tested in a Y-maze whose arms led to compartments containing unfamiliar male gerbils of varying coat colors. The stimulus animals were separated from the females by a Plexiglas door. The trials lasted for 2 min and each female was exposed to the following four combinations: two males of the same coloring as the female; one male of the same color and another of a different color from the female; both males of different color from the female. The number of crossings to the left and right arms was relayed by photocells to an IBM PC computer. The results indicate that agouti females preferred visiting the arm occupied by agouti males while those of the other coat colors showed no preference for the "wild-type" males. Instead, sandy and black female gerbils preferred to be in proximity with those of non-wild types.

Animals↗
PubMed1983

Benign familial neonatal convulsions.

A pedigree of so-called benign familial neonatal convulsions was reported. Nine members experienced convulsions in the neonatal period and/or in early infancy. All members except one had good prognosis. One member had mild mental retardation and epilepsy with rolandic EEG foci. It was suggested that some common genetic factors may be involved in the etiology of benign familial neonatal convulsions, convulsions of unknown etiology in infancy (Fukuyama) and epilepsy with rolandic EEG foci. A review of literature revealed that about 14% of cases with benign familial neonatal convulsions eventually developed epilepsy.

Adolescent↗
PubMed1983

[Experimental and clinical evaluation of cefotetan in pediatrics].

Basic and clinical studies on cefotetan (CTT) were carried out and the results were as follows: Absorption and excretion Two patients were given 10 mg/kg of CTT by one shot intravenous injection. At 30 minutes after injection, mean serum level was 76.5 micrograms/ml and the half-life time was 2.3 hours. Mean 6-hour urinary recovery in same patients was 57.5%. Clinical evaluation Forty-two patients were treated with CTT, in doses of 19.2-102.9 mg/kg divided 2-4 times per day for 3-10 days intravenously. Responses were excellent in 14, good in 23, fair in 1, poor in 4, and the overall efficacy rate was 88.1%. As to adverse reaction, urticaria was observed in 1 patient. Abnormal laboratory data noted were elevation of GOT in 1, GOT and GPT in 2, creatinine in 1, and eosinophilia in 3 patients.

Adolescent↗
PubMed1983

[Clinical evaluation of cefpiramide in pediatrics].

Cefpiramide (CPM) is a newly developed cephalosporin. Clinical studies on this drug were carried out and the results were as follows; Forty-three patients (purulent lymphadenitis 2, cellulitis 2, purulent otitis media 1, purulent tonsillitis 3, acute bronchitis 2, pneumonia 22, bronchiectasis 1, urinary tract infection 10) were treated with CPM, in doses of 20 approximately 82 mg/kg divided 2 approximately 4 times per day for 3 approximately 11 days intravenously. The overall efficacy rate was 83.7%. As to adverse reaction, 4 cases, which includes 3 cases of diarrhea and 1 case of exanthema, were observed. Abnormal laboratory data noted were liver dysfunction in 3 cases (6.8%), and eosinophilia in 2 cases (4.5%).

Adolescent↗
PubMed1982

[Basic and clinical studies on cefmenoxime in pediatric field].

Cefmenoxime (CMX) is a newly developed cephalosporin. Basic and clinical studies on this drug was carried out and the results were as follows. 1. Serum level and urinary recovery A 7 years old male was administered 10 mg per kilogram of CMX by one shot intravenous injection. Serum levels were 23.3 micrograms/ml at the time of 15 minutes after injection, 12.0 micrograms/ml at 30 minutes, 3.9 micrograms/ml at 1 hour, 2.0 micrograms/ml at 2 hours, and 0.3 micrograms/ml at 4 hours. In this same patient, 6-hour urinary recovery was 54.7%. 2. Clinical evaluation and adverse reaction Thirty-seven patients (upper respiratory infection 4, pneumonia 20, pyothorax 1, purulent lymphadenitis 1, cellulitis 2, sepsis 1 and urinary tract infection 8) were treated with CMX in doses of 30 approximately 212 mg/kg divided 3 approximately 4 times per day for 1.5 approximately 21 days intravenously. The overall efficacy rate was 94.6%. As to adverse reaction, exanthema and drug fever were observed in 1 patient respectively. Abnormal laboratory data noted were eosinophilia in 2.3%, and elevation of serum transaminase in 9.8%.

Cefmenoxime↗