Comparative investigations on the effect of different dose schedules of the phase-specific drug vincristine (VCR) on the proliferation kinetics of a solid experimental tumour

The aim of the present investigation was to study the effect of a high bolus injection (1 X 2.1 mg) of vincristine (VCR) during the phase of tumour growth retardation at the 14th day after transplantation and to compare the findings with the results of single (1 X 0.35 mg) and repeated (6 X 0.35 mg) applications of this cytostatic drug. Furthermore, an attempt was made to induce a synchronization of tumour cell proliferation. It was found that the effect on the volume growth was very pronounced after the high bolus injection and the repeated application of vincristine compared with the single low dose of the cytostatic drug. A synchronization of the tumour cell proliferation by flow out of the mitotic block could not be demonstrated. On the other hand a modest simultaneous recruitment of previously non-cycling tumour cells into the cell cycle occurred in the periphery of the tumour after the high bolus injection. The repeated application and the high bolus injection of VCR increased the cytostatic effect, especially in the tumour centre, related to the more slowly proliferating tumour cell compartment.     

Comparative Investigations On the Effect of Different Dose Schedules of the Phase-Specific Drug Vincristine (Vcr) On the Proliferation Kinetics of A Solid Experimental Tumour

The aim of the present investigation was to study the effect of a high bolus injection (1 × 2.1 mg) of vincristine (VCR) during the phase of tumour growth retardation at the 14th day after transplantation and to compare the findings with the results of single (1 × 0.35 mg) and repeated (6 × 0.35 mg) applications of this cytostatic drug. Furthermore, an attempt was made to induce a synchronization of tumour cell proliferation. It was found that the effect on the volume growth was very pronounced after the high bolus injection and the repeated application of vincristine compared with the single low dose of the cytostatic drug. A synchronization of the tumour cell proliferation by flow out of the mitotic block could not be demonstrated. On the other hand a modest simultaneous recruitment of previously non-cycling tumour cells into the cell cycle occurred in the periphery of the tumour after the high bolus injection. the repeated application and the high bolus injection of VCR increased the cytostatic effect, especially in the tumour centre, related to the more slowly proliferating tumour cell compartment.     

Growth curves,morphology and ultrastructure of ten Paracoccidioides brasiliensis isolates

The yeast phase of ten P. brasiliensis isolates were studied to characterize their growth pattern, morphology and ultrastructure. Growth curves were determined after counts of total and viable fungi units (FU) during 20 days. Three growth patterns were observed: slow, reaching approximately 10–30× 10⁶ FU/tube (Pb 18, Pb 265 and PB 2); intermediate, reaching 60–150×10⁶ FU/tube (IVIC Pb 9, IVIC Pb 267, Pb SN, Pb Vitor and Pb Campo Grande) and fast, reaching 180–370×10⁶ FU/tube (Pb 2052 and Pb 192). The highest percentage of viable cells occurred on the 6th day of culture for Pb 192, Pb Campo Grande, Pb 2052 and IVIC Pb 9; on the 8th day for Pb Vitor, Pb SN, Pb 18 and IVIC Pb 267; on the 10th day for Pb 265 and on the 12th day of culture for Pb 2. Mean generation times varied from approximately 21.2 (Pb 2052) to 102.6 hours (Pb 265). The isolates showed similar morphology, except IVIC Pb 267 which did not present a typical yeast-phase at 35°C and the two fast-growing isolates (Pb 2052 and Pb 192) that presented smaller cell sizes and less tendency to clump. The ultrastructure of the isolates was similar: the cell walls presented a width of 0.1 to 0.2 °; the mitochondria presented few cristae and had equivalent patterns of distribution and morphology; the endoplasmic reticulum was scanty, presenting narrow cisternae; the vacuoles, empty or filled with electrondense material, were numerous and two to five nuclei with pores were constantly observed.     

Kinetics of the basic sections of the hemopoietic system in radiation chimeras]

During first 3 days after mice irradiation and syngeneic bone marrow transplantation in them the number of CFUs (about 0,5% of the injected cells) was stable, although the proliferation induction began 24 hours after transplantation. As it was shown by the method of "thymidine self-distruction". Twenty four hours later all the CFUs entered the mitotic cycle. On the contrary, the commited cells (granulopoesis precursors) compartment (CFUc) enters the logarithmic growth phase since the first day. The exponential growth of the CFUs number was observed from the 4th day simultaneously with the increasing of the proliferation rate of CFUc and the beginning of the recovery of the bone marrow cells total number. In late radiation chimeras (1 month after radiation and reconstitution) the total number of CFUs was 50--70% of the initial. The other hemopoetic parameters were in the normal limits.     

Proliferation and apoptosis of human T cells during replicative senescence--a critical approach

Normal human T lymphocytes growing in culture undergo replicative senescence. Previously, we have shown that in our conditions polyclonal T cells cease proliferation after about three weeks (Radziszewska et al., 1999, Cell Biol. Int. 23, 97-103). Now we present results of a more detailed analysis of in vitro growth as well as phenotypic changes of T cells. Cell cycle analysis showed that about 20% of cells were in the S phase until the 17th day of culture (young cells). The highest number of mitotic cells (phase G2/M; 10%) was observed during the first week of culture. All not dividing senescent cells were stopped in the G1 phase (after the 30th day of culture). The sub-G1 fraction which represents apoptotic cells did not exceed 8% during the whole period until the 30th day of culture. During in vitro T-cell growth, a rather rapid selection to CD3+ CD8+ cells occurs. In the presenescent (between the 17th and 30th day) and senescent populations the majority of cells (above 90%) were CD8 positive. We also have checked the expression of alpha-chain interleukin-2 (IL-2) receptor (CD25). In young and presenescent cells about one third of cells was CD25 positive, but only 15% in the pool of senescent cells. Immunoblotting analysis of p16 protein recognized previously as a marker of senescent T cells, showed its highest and transient expression in presenescent cells. A critical review of the polyclonal T cell replicative senescence model is presented.     

Combined application of misonidazole and piotron pions on mouse embryos

Mouse embryos on day 8 of gestation were irradiated with negative pions (12.5-100 rad) or 200 kV X-rays (12.5-150 rad). Misonidazole (MISO), a hypoxic cell radiosensitizer, was applied 30 min before exposure. On day 13 the fetuses were examined for lethality, growth retardation and malformation. No significant embryolethal effects were observed after irradiation alone in the dose range of 12.5-100 rad (X-rays or pions). However, MISO alone and in combination with radiation led to high rates of lethality. The frequency of growth retardation was significantly increased at 100 rad and in combined treatments at low radiation doses. MISO and irradiation with 50 rad and more induced complex damages consisting of multiple and severe malformations and growth retardation. The relative biological effectiveness (RBE) for teratogenic effects was 1.6. In conclusion, the combined application of MISO and radiation of different LET revealed a strong enhancing action compared to single treatments. The extent of enhancement depends on both radiation quality and dose.     

Changes induces by haloperidol (antidepressant drug) on the developing retina of the chick embryo

Morphological and histological studies were done on the retina of chick embryos of 6th, 10th and 16th days of incubation by a single dose of haloperidol (0.25 mg/egg), injected on day zero and 5 of incubation. To get an idea about the extent of the teratogenic effect of this drug on the development retina. Sign of malformation in the chick embryo after administration of haloperidol were seen as absent of the ear vesicles, eyes or decreased size of them. Retardation of growth of the retina at 6th, 10th and 16th days treated chick embryo were observed as evidenced of reduction of the size of the retina, associated with sign of degeneration of the retina cells.

Conclusion

The injection of haloperidol drug give rise to several side effects as retardation of growth and degeneration of the cells. The decrease of the thickness of the layers and less density of the cells was related to direct effect of the drug on the cells of this organ. Also on the DNA formation and on the retardation of cellular mitotic activates, therefore the retina appeared decrease in thickness and less cell density with degeneration its cells.     

Influence of sodium humate and nutritive conditions on the content of nucleic acids,particularly on the ribosomal ribonucleic acid in wheat roots

Changes in the nucleic acid (NA) content were studied in roots of young wheat plants cultivated under various nutritive conditions, namely in a nutrient solution, in distilled water and in a solution of sodium humate in distilled water. Changes in the ribosomal ribonucleic acid (RNA) in particular and their connection with growth rate were investigated. The amount of the NA fraction investigated (more than 90 per cent of which is represented by the ribosomal RNA) changed substantially under the cultivation conditions studied. In roots of one plant cultivated in water the content of the NA fraction investigated was at the most about 25 μg and it began to decrease as early as from the second day of cultivation. After 12 days of cultivation it decreased to 15 μg. When cultivated in Na-humate the roots contained at the most 33 μg NA, between the 5th–7th day, followed by an intensive decrease after 12 days, to 17 μg. The content of the fraction investigated in wheat plants cultivated in a nutrient solution was about double the value in comparison to these two cases with the maximal value about 60 μg between the 7th–9th day. After 12 days this amount decreased to 45 μg. The ratio between the growth rate and the NA content presented positive values only when plants were cultivated in a nutrient solution and in Na-humate until the day when the NA content ceased to increase. In the case of Na-humate this took place on the 6th day and in the case of a nutrient solution on the 9th day. Under conditions favourable for growth (in a nutrient solution and in field conditions) the precultivation of wheat plants in Na-humate resulted in a more intensive growth of roots in comparison with the root growth of plants precultivated in distilled water. In plants precultivated in distilled water for 4 days the growth rate continuously increased under favourable nutrition conditions in contrast to plants transferred from distilled water as late as on the 6th day. Their growth stopped after the transplantation and was restored only after a 2 day lag phase. On the other hand, in plants precultivated in Na-humate the transfer to favourable nutritive conditions resulted in both cases in a short term cessation of growth.     

The pool of free purine and pyrimidine nucleosides and bases in the thymocytes, and splenic T- and B-lymphocytes of C3HA mice during the growth of solid hepatoma 22a

Using reverse phase ion pair high performance liquid chromatography, the levels of free adenosine, inosine, adenine, xanthine, hypoxanthine, guanine and deoxycytidine in thymocytes and splenic T- and B-lymphocytes of C3HA mice, were studied under normal conditions and at different times (5 hrs, 1, 2, 3, 4, 5, 8 and 20 days) after transplantation of solid hepatoma 22a. The adenosine and inosine levels in thymus and spleen lymphocytes were 5 to 10 times as low as that of purine bases. Inosine was totally absent in T-and B-lymphocytes. The absolute content of adenine and guanine in thymus and spleen lymphocytes was higher compared to purine bases. It was shown that in all cases studied the decrease in hypoxanthine, xanthine and guanine levels in T- and B-lymphocytes during maximal tumour growth, i.e., on the 5th and 8th post-inoculation days as well as at the terminal period (20th day), was correlated with the decrease in the adenosine deaminase and functional activities of these cells. The level of free adenine in thymocytes and spleen T-lymphocytes during tumour growth showed a 2-4-fold increase in comparison with normal values. A dramatic decrease of intracellular concentration of deoxycytidine was observed in thymocytes and spleen T- and B-lymphocytes beginning with the 5th hour and over the whole subsequent period. The key role of the deoxycytidine decline during tumour growth as a possible cause of simultaneous impairment of DNA synthesis and purine deoxyribonucleoside phosphorylation in lymphocytes is discussed.     

Studies of the effect of 0.4-Gy and 0.6-Gy prenatal X-irradiation on postnatal adult behavior in the Wistar rat

Thirty-four pregnant Wistar rats were X-irradiated on the 9th or 17th day of gestation at a dosage level 0.4 Gy or 0.6 Gy or were sham-irradiated. All mothers were allowed to deliver their offspring, and litters were limited to a maximum of eight on day 2. On day 30, 224 offspring were weaned and raised until 60 days of age, at which time testing began. Each rat randomly received, in random order, three of the following six behavioral tests: Water T-maze, Conditioned Avoidance Response, Forelimb Hanging, Activity Wheel, Swimming, and Open Field. There were no statistically significant differences between the irradiated and control groups for maternal weight or weight gain or mean litter size, although the litter size of the 17th day 0.6-Gy group was slightly lower. Among offspring irradiated with 0.6 Gy on the 17th day, 3-day-old neonates' weights were significantly reduced. Offspring irradiated on the 17th day with 0.6 Gy exhibited higher Conditioned Avoidance Response 5th-day and retest avoidance scores than did the controls. There were also significant sex differences in responses within the irradiated and control groups for several tests, which were unrelated to radiation exposure. The results of this study indicate that low-level X-irradiation during the fetal period of rat gestation results in neonatal growth retardation and subtle behavioral alterations that may be manifested in adult life. Growth retardation may be the most sensitive indicator of subtle effects that result from low-level prenatal exposure to X-rays.     

移植途径对大鼠骨髓间充质干细胞归巢及肝功能恢复的影响

目的 探讨移植途径对骨髓间充质干细胞（MSCs）归巢及促进肝切除大鼠肝再生的影响.方法 建立肝切除大鼠模型,随机分为3 组,即肝切除对照组、尾静脉移植组和门静脉移植组.移植组分别经尾静脉和门静脉注射DAPI 标记的MSCs 约1.5×106/ 只,分别于第3 天和第9 天后采血清检测肝功能,第9 天处死大鼠取肝脏标本,并通过荧光显微镜观察两种移植途径对MSCs 向肝脏迁移的影响.结果 门静脉移植组（18.1 ± 3.4）个细胞/100 倍视野到肝脏归巢及定植的 MSCs 多于尾静脉移植组（7.6 ± 2.0）个细胞/100 倍视野,差异有统计学意义（P 〈 0.01）.术后第9 天各组大鼠肝功能均有好转,丙氨酸氨基转移酶（ALT）及天冬氨酸氨基转移酶（AST）3 组之间对比差异无统计学意义（F = 2.822,1.046,P = 0.057,0.365,P 〉 0.05）;但两移植组与单纯肝切除组比较血浆白蛋白（ALB）均有明显升高,差异具有统计学意义（F = 6.259,P = 0.006）;尾静脉移植组与门静脉移植组两移植组之间相比,差异无统计学意义（P 〉 0.05）.结论 移植途径对 MSCs 归巢、定植到肝脏有一定影响,门静脉途径优于外周静脉,MSCs 移植对肝大部切除大鼠肝功能恢复具有促进作用.     

Single cell analysis of changes in electrokinetic properties of a growing ascitic tumor.

An ascitic tumor (SEWA) induced by polyoma virus in A.SW mice was analyzed in vivo as well as in vitro with regard to the electrophoretic mobility (EPM) which may be considered as a reliable criterion of surface charge. After the i.p. transplantation of 10(5) cells, the EPM decreased up to 14th day. Then, the mobility gradually increased with the age of the tumor. In the first phase of tumor growth, we have considered the possibility that immunoglobulin cell coating may be responsible for the decrease in EPM. In the late phase of SEWA growth, the progressive increase in EPM might be due to a rearrangement of sialic acids on the outer part of the cell membrane.     

Circadian synchronization of hepatocyte proliferation in young rats: the role played by adrenal hormones

The circadian rhythm of hepatic cell proliferation in rats appears on the 20th day of life, when the hypothalamo-adrenal axis is mature enough for circadian activity to occur. From the 20th day to the 30th day of life, the mitotic rhythm is progressively induced by a reduction in nocturnal values, while diurnal rhythms remain unchanged. Mitotic peaks emerge at 10.00 hours. A labelling index wave occurs 8 hr before the corresponding mitotic wave, with a peak at 02.00 hours and a minimum in the evening, coincidental with the acrophase of plasma corticosterone level (activity phase). Labelled mitoses curves and metaphase accumulation after colchicine injection show that the duration of the S, G2 and M phases remain approximately constant and that the circadian variation is due to a variation in the rate of cells that enter these successive phases. During the synchronization period (from day 20 to 30), the growth fraction decreases progressively. Adrenalectomy at this time is followed by a higher cell proliferation and all rhythms disappear after 2 days. Corticosterone injected before the triggering of the rhythmic activity in 17-day-old rats immediately reduces the labelling index, while the mitotic index is decreased 10 hr later; this delay is equal to the S + G2 duration. The results are discussed. They favour the hypothesis that the circadian variation of corticosterone is responsible for the induction of a circadian variation in developmental cell proliferation by inhibition of the G1-S transition when it is higher in the evening.     

Iron mediated regulation of growth and siderophore production in a diazotrophic cyanobacterium Anabaena cylindrica

Iron mediated regulation of growth and siderophore production has been studied in a diazotrophic cyanobacterium Anabaena cylindrica. Iron-starved cells of A. cylindrica exhibited reduced growth (30%) when the cells were growing under N2-fixing conditions. In contrast, N03-, NO2-, NH4' and urea grown cells exhibited almost 50% reduction in their growth in the absence of iron as compared to their respective counterparts cultured in the presence of iron. However, at 60 microM of iron, A. cylindrica cells exhibited almost equal growth regardless of the nitrogen source available. Siderophore production in A. cylindrica was started after day 2nd of the cell growth and attained its optimal level on day 5th when the cells were at their mid-log phase. No siderophore production was, however, recorded on day 2nd at all the concentrations of iron tested. The production of siderophore in A. cylindrica further increased with increase in iron concentration and attained its optimum level on day 5th at 60 microM iron. A. cylindrica cells took at least 3 days for initiation of siderophore production and produced about 60% siderophore on day 5th even under iron-starved condition. A. cylindrica produced dihydroxamate type of siderophore.     

Cellular activities associated with the transition of chick embryo fibroblasts from stationary to proliferation state

Chick embryo fibroblasts on the 5th day of culture in proteinfree medium were stimulated to accelerated growth by supplementation of the medium with ATP (50 mumol/l, insulin (0.16 I.U./ml) or chick serum (5% v/v). Kinetics of the entry of cells into the S phase and later into the logarythmic phase of growth were found to be different in cultures treated with these three factors in spite that the final saturation densities reached after 30 days of culture were similar. No direct correlation between cell spreading and the cell transition from the stationary to the proliferation state was found. The proliferating cells showed the higher rate of locomotion than in stationary cultures. The initial protein-free medium, supporting the long survival of chick embryo fibroblasts and their susceptibility to growth accelerating factors, was further simplified by replacement of ADA buffer with EDTA (0.4 mmol/l).     

The development of the guinea pig gallbladder epithelial cells. II. Electron microscopical and enzymhistochemical investigations (author's transl)]

The development of the guinea pig gallbladder epithelium follows a distinct time schedule. During the first phase (up to 30th day of intrauterine life) the epithelial cells increase in number. They remain small and undifferentiated. In the second phase, from the 30th to the 44th day, cytodifferentiation is a dominating feature. The epithelial cells increase in height, the nuclei become more basal, the cells acquire their final zonal structure and the cell organelles exhibit their characteeristic appearance. Weak enzyme activities can be observed. In the third phase, from the 45th day until birth, there is functional differentiation and the adult pattern of enzyme distribution is established. Glycogen appears first on day 29, increases in amount and then disappears by day 57. There is a marked development of the Golgi apparatus associated with increased synthesis of secretory material. Between the 59th embryonic day and the 6th day of life mucoid cells with different functional states appear in the gallbladder epithelium. Later on these cells can be visualized only in the depths of the invaginations. After birth the epithelial cells become more columnar and by 10 days after birth the adult appearance of the epithelium is fully established.     

Circadian synchronization of hepatocyte proliferation in young rats: the role played by adrenal hormones

Abstract. From the 20th day to the 30th day of life, the mitotic rhythm is progressively induced by a reduction in nocturnal values, while diurnal rhythms remain unchanged. Mitotic peaks emerge at 10.00 hours.
A labelling index wave occurs 8 hr before the corresponding mitotic wave, with a peak at 02.00 hours and a minimum in the evening, coincidental with the acrophase of plasma corticosterone level (activity phase).
Labelled mitoses curves and metaphase accumulation after colchicin injection show that the duration of the S, G₂ and M phases remain approximately constant and that the circadian variation is due to a variation in the rate of cells that enter these successive phases. During the synchronization period (from day 20 to 30), the growth fraction decreases progressively. Adrenalectomy at this time is followed by a higher cell proliferation and all rhythms disappear after 2 days.
Corticosterone injected before the triggering of the rhythmic activity in 17-day-old rats immediately reduces the labelling index, while the mitotic index is decreased 10 hr later; this delay is equal to the S + G₂ duration.
The results are discussed. They favour the hypothesis that the circadian variation of corticosterone is responsible for the induction of a circadian variation in developmental cell proliferation by inhibition of the G₁-S transition when it is higher in the evening.
The circadian rhythm of hepatic cell proliferation in rats appears on the 20th day of life, when the hypothalamo-adrenal axis is mature enough for circadian activity to occur.     

Effect of transplantation of embryonic neural tissue on the dynamics of brain edema following experimental craniocerebral trauma

The effect of transplantation of embryonic neural tissue (ENT) on the dynamics of brain edema following heavy craniocerebral trauma (CCT) made to the left parietotemporal area was studied in rats. The brain tissue impedance was measured in the damaged and contralateral hemispheres 1 to 30 days after the trauma in the animals of three groups: (i) without any procedures after the CCT, (ii) with surgical treatment of the damaged brain area, and (iii) with transplantation of 1–2 mm³ sensorimotor cortex fragments from 18-day-old rats grafted into the cavity created by this treatment. At the first day after CCT, the impedance in the damaged hemisphere decreased by 30–37%, while the impedance in the contralateral hemisphere decreased approximately by 20%, compared with the control, which was evidence of the development of intensive generalized edema. In the group of animals with the ENT transplantation, the edema involuted noticeably faster than in the other two groups: the mean impedance value reached 97.9% of the control value (before the damage) already by the 7th post-traumatic day. Complete recovery of the impedance by the 30th day was observed only in the animals with transplantation. The adequacy of an impedancemetric technique for investigation of the dynamics of water-electrolyte re-distribution in the brain tissue, and the mechanisms underlying corrective effect of ENT transplantation on the edema dynamics in the post-traumatic period are discussed.     

Changes in arginase activity during neurinoma growth

Arginase activity was studied in the brain and other tissues of the rat at the different periods of neurinoma growth. The activity of the enzyme was considerably activated in the affected hemisphere on the 4th day, in the skin of the head and thigh on the 6th day after tumor transplantation. Elevation in arginase activity in the neoplasm itself was recorded on the 16th day. The data obtained point to the physiological significance of arginase during neurinoma growth.     

Changes in growth characteristics of mouse ascites tumor AISM during the process of passage in vivo

The growth characteristic of mouse ascites tumour AISM was observed on two distant passages (35th and 117th) in vivo. The following growth differences were established; the duration of life time of tumour bearing mice is less at the 35th passage (8 days) in comparison to the 117th passage (12 days); the common tumour cell mass at the terminal stage of life of tumour is more than 10 times less at 35th passage (10(8) cells) than at 117th passage (1.2.10(9) cells). The growth rate at 35th passage increases to the 4th day and at 117th passage to the 6th day. It is suggested that the tumour growth rate and the final size of tumor cell mass depend on the cell ploidity and chalone growth control.