Prolongation Of Latent Period Research Articles

Chemical and Biological Investigation of Sanchezia nobilis Leaves Extract

The project work was designed to investigate the phytochemical and selected pharmacological activities (anti-diarrheal, analgesic, neuropharmacological behavior and anthelmintic) of leaves of Sanchezia nobilis. Hook. F. (Family: Acanthaceae). From its phytochemical analysis we found the presence of reducing sugar, combined reducing sugar, phenolic compounds, tannins, flavonoids, carbohydrates, gums, steroids, alkaloids, glycosides and terpenoids. In vivo antidiarrheal activity was substantiated by prolongation of latent period and decrease in total number of stools. The extract produced 62.49% and 74.01% decrease in stool count at the doses of 250 and 500 mg/kg body weight respectively while the standard drug Loperamide decrease in stool count was found to be 87.05% at a dose of 3 mg/kg body weight. The leaves extract produced 32.7% and 41.78% inhibition of writhing at the doses of 250 mg/kg and 500 mg/kg body weight respectively while the standard drug Diclofenac Na was found to be 74.23% at a dose of 25 mg/kg body weight. The extract showed dose dependent CNS depressant activity by reducing the locomotors activity. Higher dose of this extract (500 mg/kg body weight) comparing with standard Diazepam exposed sedative effect potentially. The extract exhibited concentration dependent anthelmintic activity against Paramphistomum cervi using Albendazole (15 mg/mL) as standard. The paralysis occurred between 9.00 to 83.91 min and death occurred between 11.33 to 86.33 min which were comparable to standard drug Albendazole. So, the present study concluded that the extract is fortified with significant antidiarrheal, CNS depression and anthelmintic activity and moderate analgesic activity.

Inhibition of Mammary Tumors by Incomplete T-Cell Depletion 2

The effects of neonatal and perinatal thymectomy on mammary tumorigenesis in (C57BL X I)F1fC3H hybrid female mice were determined. When hybrid females were neonatally thymectomized by controlled suction, a procedure that removes thymic lobes completely, a large proportion of animals developed stigmas of a fulminant wasting disease and died before tumors developed. However, when hybrid females were subjected to neonatal thymectomy by continuous suction, a procedure that resulted in retention of thymic remnants, they survived and manifested a significant prolongation of latent period before tumorigenesis. When complete removal of the thymus was carried out in the perinatal period, the effect on mammary tumorigenesis was critically dependent on the age at surgery. The procedure was without effect when performed at 1, 3, and 8 weeks of age. However, when it was performed at 9-12 days of age, there was a delay or a decrease in the appearance of mammary tumors. The extent of T-cell depletion and/or its timing in relationship to the introduction of murine mammary tumor virus appeared to play a critical role in determining the effect on eventual tumor development.

INHIBITION OF TUMOR AND FETAL TISSUE GROWTH IN NEWBORN RECIPIENTS

A comparative study of growth of a variety of fetal tissues and transplantable tumors in syngeneic newborn and adult mice was carried out. Tumors used in the experiments arose spontaneously (hepatomas, mammary gland adenocarcinoma) or resulted from malignant conversion of ectopic transplants either of fetal tissues (urinary bladder carcinoma, adenocarcinoma of small intestine, stomach sarcoma) or of adult animal tissues (ovary carcinoma) in syngeneic system. The growth of "teratomas" developed after transplantation of minced tissues of 18-20-day fetuses was considerably inferior in newborn syngeneic recipients as compared to analogous transplants in adults. Inhibition of tumor growth was also observed in newborn animals. It was manifested in prolongation of latent period before tumor node appearance as well as in slowing down of growth rate of developed tumors. Only one tumor, mammary gland adenocarcinoma, proved to be an exception, its growth being equally progressive in newborn and adult recipients. At transplantation of tumor cells mixed with lymphocytes of adult mouse spleen, stimulation of tumor growth in newborns and inhibition of growth in adult recipients was observed. It is suggested that there exists a special type of cellular or humoral mechanism controlling tumor growth in newborns. The activity of such factors is conceivably based on fetal antigens as targets.

Nonimmune and Immune Surveillance. I. Growth of Tumors and Normal Fetal Tissues Grafted Into Newborn Mice

Growth of various fetal tissues and transplantable tumors in syngeneic newborn and adult mice [BALB/c, DBA/2, and (CBA X C57BL/6J)F1] was compared. Fetal skin, a mixture of all fetal tissues, and tumors were transplanted. The tumors arose spontaneously [hepatomas, mammary gland adenocarcinoma (MGAC)] or resulted from malignant conversion of ectopic transplants either of fetal tissues (urinary bladder carcinoma, adenocarcinoma of small intestine, stomach sarcoma) or of adult animal tissues (ovarian carcinoma) in the syngeneic system. The growth of fetal skin transplants and teratomas, which developed after transplantation of minced tissue from 18- to 20-day and 12- to 14-day fetuses, was considerably inferior in newborn syngeneic recipients, as compared with similar transplants in adults. Inhibition of tumor growth observed in newborn animals was manifested in prolongation of latent period before tumor node appearance and in slowing of growth rate of developed tumors. One of six tumors studied (MGAC) grew at the same rate in newborn and adult recipients. It was suggested that a special type of cellular and/or humoral mechanisms controlling tumor growth exists in newborns. The activity of such factors was conceivably based on fetal tumor antigens as targets. We assumed that weakly antigenic and strongly antigenic tumors behaved differently in respect to nonimmune and immune surveillance mechanisms.

Effects of thiamine and its derivatives on the isolated toad heart muscle.

In order to reevaluate the effects of thiamine and its derivatives in large dosis on heart muscle, the following experiments on the isolated toad heart were performed.1. Using Yagi's apparatus of recycling, the action on the contractile power was observed. It was confirmed that thiamine-HCl, thiamine propyl disulfide (TPD), thiamine tetrahydrofurfuryl disulfide (TTFD), thiamine disulfide and oxythiamine increased the contractile power. Especially, in the concentration of 1.4mM, the action of TPD and TTFD was so pronounced that approximately doubled values of the contractile deflection, cardiac output and aortic pressure were recorded. However, thiamine diphosphate showed no action during the period of time tested. Thiaminic acid showed even the inhibitory action.2. In the concentration of 1.4mM, TPD caused the prolongation of latent period and repolarization phase of transmembrane action potential.3. The oxygen consumption of recycling toad heart was measured manometrically with a modified Warburg chamber. When the contractile power increased on the administration of TPD, the cardiac efficiency did not diminish in spite of the increase of oxygen consumption.

溶原菌に於けるファージ増殖に関する研究

The effect of chloramphenicol on the phage development of UV induced E. coli, K12 (λ) was investigated by the one step growth experiment and the quantitative analyses of protein and of DNA synthesis.When chloramphenicol is added to the induced culture at any time between 40 and 60 minutes after induction (the minimum latent period of λ is 60 minutes), induced cells lyse prematurely and the mature phage particles are liberated. Introduction of chloramphenicol during the first 35 minutes, however, is followed by a consequence that the number of infective centers tested gives less than the number of treated bacteria. These results are in fair agreement with Delbrück's finding which has been ascertained by the technique of stopping phage growth and making the cells to lyse prematurely by exposure to the KCN. It is confirmed that chloramphenicol treatment inhibits the induced bacteria from further phage development-similarly to the experiments with strain B infected with T1, and that the mature phage particles begin to appear in induced bacteria at about 40 minutes after induction.At the earlier stages of the phage development, the chioramphenicol inhibition is reversibly removed and its influence does not seem to be reserved when the drug is diluted out. Namely, the length of the latent period is prolonged as much time as one of the exposure to the chloramphenicol, and essential latent period is not affected by the additions up to 45 minutes after induction; there is no prolongation of latent period and bacteria burst at normal latent period, if induced bacteria are still later exposed to chloramphenicol. The average phage yield too is not influenced by the presence of chloramphenicol for a short period either at initial or terminal stage. However, a, marked decrease in burst size is noted with the interruption of phage development at the middle portion, i.e. in this case there seems to be a somewhat irreversible effect of chioramphenicol on the mechanism of phage develpment.In a growing culture of K12, chloramphenicol at bacteriostatic concentrations depresses the both ribonucleic and desoxyribonucleic acid syntheses considerablly, but a lesser extent in comparison with the complete inhibition of protein synthesis. An identical suppression is also found in the DNA synthesis of induced bacteria, when chloramphenicol is added as late as 30 minutes after induction. In contrast, the chloramphenicol addition immediately after induction shows the complete inhibitory effect on the phage DNA synthesis, as on the protein synthesise Further more, the synthesis of phage DNA begins lately as equal to the affecting time of chioramphenicol when the bacteria are exposed to the drug for a given period after induction.These results indicate that the DNA synthesis of the induced K12 requires the new metabolic system (s) which does not participate in the host DNA synthesis, and that some enzyme proteins constructing such system (s) are synthesized immediately after induction and are continued to be formed during the first half of the latent period. It seems more adequate in the “photorestorable phase” to be interpreted not merely as the conversion of the prophage into the vegetative state takes place, but also as the metabolic reactions for phage development are already initiated.

溶原菌におけるプアージ増殖に関する研究

The effect of chloramphenicol on the phage development of UV induced E. coli, K12 (λ) was investigated by the one step growth experiment and the quantitative analyses of protein and of DNA synthesis.When chloramphenicol is added to the induced culture at any time between 40 and 60 minutes after induction (the minimum latent period of λ is 60 minutes), induced cells lyse prematurely and the mature phage particles are liberated. Introduction of chloramphenicol during the first 35 minutes, however, is followed by a consequence that the number of infective centers tested gives less than the number of treated bacteria. These results are in fair agreement with Delbruck's finding which has been ascertained by the technique of stopping phage growth and making the cells to lyse prematurely by exposure to the KCN. It is confirmed that chloramphenicol treatment inhibits the induced bacteria from further phage development-similarly to the experiments with strain B infected with T1, and that the mature phage particles begin to appear in induced bacteria at about 40 minutes after induction.At the earlier stages of the phage development, the chioramphenicol inhibition is reversibly removed and its influence does not seem to be reserved when the drug is diluted out. Namely, the length of the latent period is prolonged as much time as one of the exposure to the chloramphenicol, and essential latent period is not affected by the additions up to 45 minutes after induction; there is no prolongation of latent period and bacteria burst at normal latent period, if induced bacteria are still later exposed to chloramphenicol. The average phage yield too is not influenced by the presence of chloramphenicol for a short period either at initial or terminal stage. However, a, marked decrease in burst size is noted with the interruption of phage development at the middle portion, i.e. in this case there seems to be a somewhat irreversible effect of chioramphenicol on the mechanism of phage develpment.In a growing culture of K12, chloramphenicol at bacteriostatic concentrations depresses the both ribonucleic and desoxyribonucleic acid syntheses considerablly, but a lesser extent in comparison with the complete inhibition of protein synthesis. An identical suppression is also found in the DNA synthesis of induced bacteria, when chloramphenicol is added as late as 30 minutes after induction. In contrast, the chloramphenicol addition immediately after induction shows the complete inhibitory effect on the phage DNA synthesis, as on the protein synthesise Further more, the synthesis of phage DNA begins lately as equal to the affecting time of chioramphenicol when the bacteria are exposed to the drug for a given period after induction.These results indicate that the DNA synthesis of the induced K12 requires the new metabolic system (s) which does not participate in the host DNA synthesis, and that some enzyme proteins constructing such system (s) are synthesized immediately after induction and are continued to be formed during the first half of the latent period. It seems more adequate in the “photorestorable phase” to be interpreted not merely as the conversion of the prophage into the vegetative state takes place, but also as the metabolic reactions for phage development are already initiated.