Nonselective cation channels activated by the stimulation of muscarinic receptors in mammalian gastric smooth muscle.

Muscarinic receptors play key roles in the control of gastrointestinal smooth muscle activity. However, specific physiological functions of each subtype remain to be determined. Single cell RT-PCR experiments showed that all five subtypes of muscarinic receptors were present in circular smooth muscle cells of the guinea-pig gastric antrum. Nonselective cation channels (NSCC) activated by ACh or CCh are coupled to pertussis toxin (PTX)-sensitive Go protein through m4 subtype as well as m2 and m3 subtypes in guinea-pig stomach. CCh-activated currents (I(CCh)), especially the steady-state I-V relationship of I(CCh) showed a chracteristic U-shaped curve; reversal potential of around 0 mV and inward rectification at around +15 mV and a negative slope conductance at negative potential range. Under physiological conditions, the measured single channel conductance of NSCC was approximately 25 pS. The single channel conductance was modulated by external monovalent and divalent cations including Na+, Cs+, Li+, and Ca2+ through changing both the open probability and unitary conductance. Through the NSCC, Ca2+ can move into the cell from extracellular solution as well as Na+. Calculated fractional Ca2+ current of I(CCh) (f(Ca)) was around 1% at the 2 mM [Ca2+]o and at the 4 mM [Ca2+]o, f(Ca) was 2.3%. Quinidine blocked I(CCh) potently in a reversible manner; IC50 was 0.25 microM. There were two kinds of I(CCh) modulations through Ca(2+)-dependent pathways in guinea-pig gastric smooth muscle cells; 1) Facilitation of I(CCh) via Ca2+/CaM-dependent MLCK pathway, 2) Desensitization of I(CCh) via Ca(2+)-dependent PKC pathway. In the mouse stomach, all seven types of TRPC mRNA were detected with RT-PCR. On the basis of electrophysiological, pharmacological, and molecular biological experiments, we reported the mTRPC5 as a candidate for the NSCC activated by muscarinic stimulation in mouse stomach.     

Application of cytopathology in a sensitivity test for anti-tumor agents. I. An experimental study

Although the human tumor clonogenic assay (HTCA) is extremely reliable in determining clinical correlations, it is a complicated process requiring considerable time in order to obtain results. Thus, an experimental study on cytopathologic observation (cytologic assay) and comparative evaluation between it and HTCA were performed in order to establish a more rapid and accurate drug sensitivity test. Materials included Colon 26, a cell line established in our department, malignant effusion and surgical specimens. In carrying out HTCA according to the Hamburger-Salmon method, the cell suspension samples following exposure to anti-tumor agents (MMC, L-PAM, ADM, CDDP) were cultivated in test tubes for 3-8 hours and stained by the Papanicolaou and Giemsa methods. According to Tokita's criteria, when cellular changes showed as nuclear pyknosis and nuclear destruction were found to have increased significantly in comparison with a control group, the cells were judged to be sensitive. Very similar and parallel results were obtained between HTCA and cytologic assay in this study, with a significant correlation. Cytologic assay was proved to be an easy, rapid and accurate method for testing drug sensitivity and its clinical application can be expected in the future.     

Kindling of the visual cortex in cats: comparison with amygdaloid kindling

Kindling of the primary visual cortex (VC) was compared with that of the amygdala in cats. VC kindling was basically similar to kindling of the amygdala in that daily electrical stimulation can lead to the development of a generalized convulsion in most subjects, a growth of afterdischarges in their configuration and duration, and a reduction of the afterdischarge threshold. The kindling response of the VC differed from that of the amygdala in a number of respects, i.e., a high afterdischarge threshold, a different pattern of behavioral seizure development, an abrupt growth of electroclinical seizures coincident with the onset of a generalized convulsion, an intersubject variability in seizure susceptibility, and a marked seizure instability. In VC kindling the afterdischarge propagation into the amygdala was not observed until the generalized convulsion developed, and the early involvement of afterdischarge was seen in the pulvinar, lateral geniculate body, and superior colliculus. These data suggest that a neural mechanism different from amygdaloid kindling may participate in VC kindling, and that the subcortical structures of the visual system are involved in the preferential pathway for a seizure generalization from the VC.     

Clinical study of estramustine phosphate disodium (Estracyt) on prostatic cancer--results of long-term therapy for 38 patients with prostatic cancer

Estramustine phosphate disodium (Estracyt) was used in the treatment of 38 patients with prostatic carcinoma for at least 1 year. Of these patients 37 patients were treated with Estracyt as primary treatment and 1 patient had been treated with another antiandrogenic therapy before the Estracyt treatment. Estracyt was given orally in a dose of 560 mg/day in divided oral doses. The clinical evaluation was done for the change of PAP, the relapse rate, the survival rate and the side effect. Among 22 cases which had shown abnormally high PAP values before the treatment started, the values decreased or normalized in 21 cases (95.5%) in the first year of administration of Estracyt. In 6 cases, however, the values increased again in the second year or later. Relapse was observed in 10 (26.3%) out of 38 cases. Relapse rate was 2.6%, 51.7%, and 51.7%, at the first, third, and fifth year, respectively. Survival rate was 97.4% at the first year, 88.5% at the third year, and 68.8% at the fifth year for the follow-up study. Side effects were observed in 14 (36.8%) out of 38 cases. The main side effect was gynecomastia. Gastro-intestinal disturbance and edema were also observed. However, there were only 2 cases (5.2%) in which administration of Estracyt had to be discontinued.     

Correlation between changes in obesity from adolescence to young adulthood and family obesity--the results of cross sectional and longitudinal studies

We conducted a survey of 356 married couples and their 552 children living in Hisayama in Fukuoka prefecture in order to investigate the correlation between changes in obesity from adolescence to young adulthood. 1. A positive correlation between couples in weight and height could be found, but its coefficient was weak (r = 0.12, 0.10). There was no correlation between couples in BMI. 2. The correlation between parents and their children in height, weight and BMI was significantly positive (r = 0.18, 0.45), having a coefficient greater than that of the correlation between married couples. 3. The correlation coefficient between mother and child was greater than that of the correlation coefficient between father and child. 4. The BMI of a child with either parent obese was significantly greater than that of a child with neither parent obese. Obesity appeared more frequently in children whose BMI of parent was higher. 5. A positive correlation between the BMI of young adults and that of adolescents could be found, and the average BMI of the obesity group was higher than that of the non-obesity group even in the adolescent subjects. 6. Even after considering BMI during adolescence, the familial factor had a significant relationship to the BMI of young adulthood. These results suggest that obesity in adolescence will influence obesity in young adulthood, and that the appearance of obesity strongly correlates with the familial obesity factor. In conclusion, it is very important to take preventative measures, in cooperation with the family, early in a child's adolescent years in order to avoid obesity in adulthood.     

Retarded and distinct progress of lens opacification in congenic hereditary cataract mice, Balb/c-nct/nct

The Nakano cataract gene, nct, was introduced into Balb/c mice by repeated backcrosses to elucidate the possible effects of background genes on its expression. The resulting congenic Balb/c-nct/nct mice were characterized by retarded and sporadic cataract formation with a tendency of further retardation in males and by the different disease process of cataract as compared with Nakano mice. The age of 50% cataract incidence was 60 days in females and 90 days in males compared with 22 days in Nakano mice, and lens opacification commenced in a diffuse, mild form at the cortex in congenic but in a pin-head, intense form at the core in Nakano mice. Sex hormones seemed to be involved in the difference in cateractogenesis between male and female mice. Microphthalmia was slighter in degree in Balb/c background mice. The results indicated that the nct-dependent cataractogenesis may be influenced by background genes and some non-hereditary factors. Balb/c-nct/nct mice will provide a new type of hereditary cataract model.