RESUMEN
Regular features of spirals of chitinous filaments of tracheas were investigated in 12 species of insects. All species studied were found to have mosaic heterochirality, i.e. portions of opposite directions of curling in the trachea system, and prevalence of rightness or leftness in them. The percentage correlation of rightness-leftness are characteristic of each species and may be considered as hereditary features. The degree of prevalence of the rightness or leftness in some species as well as the degree of chiral purity (according to this parameter) is not connected with the direction of curling. The tendency to chiral purity is distinctly seen in species with both the right and left curling. As for the problem of species formation, it should be admitted that the independence of the curling direction on the one hand, and the prevalence of its degree--and the degree of chiral purity--on the other hand, speaks in favor of different mechanisms of their development. It is also confirmed by the fact that the distribution of the curling direction is referred to the whole complex of species while the degree of prevalence of any kind of curling and the degree of chiral purity are distinctive individual characteristics and are developing as a result of the adaptation selection, in connection with other features of the given species. At the same time, in accordance with some scientists it may be supposed that the directions of curling is developing on the basis of molecular structures and are thought to be accidental. Regular features of curling of trachea formations are different depending on localization of organs. For example, the tracheas feeding the malpighian vessels form spirals curling around every malpighian vessel and always to the right. Neither the trachea, nor the vessels form spirals without being in contact.
Asunto(s)
Insectos/anatomía & histología , Animales , Quitina , Túbulos de Malpighi/anatomía & histología , Especificidad de la Especie , Tráquea/anatomía & histologíaRESUMEN
After large-field fractionated irradiation of dogs at a cumulative dose of 54 Gy, a stable bone marrow depletion occurs persisting for a year following irradiation. The automyelotransplantation after the end of the exposure elicits a transient recovery of the exposed bone marrow, 1.5-2 months after the beginning of irradiation, followed by a secondary depletion of the exposed haemopoietic sites. The control and the automyelotransplanted animals exhibited bone marrow recovery one year and six months after irradiation, respectively, the cellularity being maintained at a high level for 3 years of observation.
Asunto(s)
Trasplante de Médula Ósea , Animales , Médula Ósea/patología , Médula Ósea/efectos de la radiación , Recuento de Células/efectos de la radiación , Perros , Relación Dosis-Respuesta en la Radiación , Femenino , Hematopoyesis/efectos de la radiación , Masculino , Factores de Tiempo , Trasplante AutólogoRESUMEN
In experiments on (CBA X C57BL)F1 hybrids it was shown that the administration of sublethal doses of endotoxin to locally exposed (spleen, 9 Gy) animals enhanced the repopulation of the exposed haemopoietic tissue (spleen and bone marrow). It is concluded that endotoxin has a favourable action on the recovery of haemopoiesis of partially irradiated mice which confirms the idea of the possibility of using stimulators instead of autotransplantation of bone marrow from intact parts.
Asunto(s)
Endotoxinas/uso terapéutico , Hematopoyesis/efectos de los fármacos , Células Madre Hematopoyéticas/efectos de los fármacos , Traumatismos Experimentales por Radiación/tratamiento farmacológico , Animales , Movimiento Celular/efectos de los fármacos , Movimiento Celular/efectos de la radiación , Hematopoyesis/efectos de la radiación , Células Madre Hematopoyéticas/efectos de la radiación , Masculino , RatonesRESUMEN
In experiments on (CBA X C57Bl)F1 and BALB/c mice it was shown that with the spleen mass increasing, due to exo- and endorepopulation, during the postirradiation regeneration of the spleen, the number of splenic colonies also increases to a certain level. When the spleen mass reaches 1/3 of that lost after irradiation the number of discrete colonies decreases. When the spleen mass is restored to about 1/2 solitary colonies do not form at all. The spleen mass can considerably exceed the normal level in conditions of intensive repopulation.
Asunto(s)
Hematopoyesis/efectos de la radiación , Bazo/efectos de la radiación , Animales , Trasplante de Médula Ósea , Ensayo de Unidades Formadoras de Colonias , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Tamaño de los Órganos/efectos de la radiaciónRESUMEN
The effect of an automyelotransplant taken from a nonirradiated area of bone marrow has been studied after large fields irradiation in dogs. Certain changes occurring in the hemopoietic organs and in some other vitally important organs have been revealed. The automyelotransplantation contributes to a quicker repopulation of the bone marrow and stimulates lymphoid hemopoiesis in the spleen; that plays a positive role in overcoming the bone marrow syndrome at radiation illness. In other organs (gastrointestinal tract, kidneys, lungs, heart) given various doses of irradiation, in the control and test (with automyelotransplantation) groups similar morphological changes have been revealed.
Asunto(s)
Trasplante de Médula Ósea , Hematopoyesis/efectos de la radiación , Traumatismos Experimentales por Radiación/patología , Animales , Médula Ósea/patología , Recuento de Células , Perros , Femenino , Masculino , Dosis de Radiación , Traumatismos Experimentales por Radiación/terapia , Bazo/patología , Trasplante AutólogoRESUMEN
Experiments on linear F1 (CBA x C57BL) mice resistant to irradiation and random-bred white mice which are more sensitive to irradiation were made to study the relationship of the survival rate of the animals and spleen colony formation to the magnitude of x-ray doses during immobilization and shielding of the crus--factors which increase the resistance. It was shown that low colony formation typical for linear mice remained at a low level during the resistance-increasing immobilization, while in the course of shielding it increased in accordance with the animals' survival rate. In random-bred mice, the survival rate and colony formation were in good agreement in all the cases. The conclusion is made that colony formation cannot be regarded as an adequate criterion for the survival rate.
Asunto(s)
Médula Ósea , Ensayo de Unidades Formadoras de Colonias , Inmovilización , Traumatismos Experimentales por Radiación/mortalidad , Protección Radiológica , Animales , Relación Dosis-Respuesta en la Radiación , Masculino , Ratones , Rayos XAsunto(s)
Médula Ósea/efectos de la radiación , Protección Radiológica/métodos , Restricción Física , Animales , Masculino , Ratas , Rayos XRESUMEN
The migration rate of stem hemopoietic cells (SHC) of the bone marrow was studied by two methods in experiments on 54 dogs. In the first case the dogs were irradiated with an absolute lethal dose (550 R) subtotally, shielding two knee-joints. Seven days after the first irradiation under inactivation of shielded parts with 2000 R dose the survival rate was 12.5% and after 14-day inactivation all the dogs survived. In the second case firstly both knee-joints were irradiated with 2000 R dose. All the animals died following subsequent subtotal irradiation of the areas previously irradiated with 550 R dose if the second irradiation was performed 7 days after the first one. Prolongation of the time intervals between irradiations up to 31 days lead to 20% survival of the animals. It was concluded that SHC migration in dogs is much lower than in mice.
Asunto(s)
Células Madre Hematopoyéticas/efectos de la radiación , Animales , Médula Ósea/efectos de la radiación , Movimiento Celular/efectos de la radiación , Perros , Femenino , Articulación de la Rodilla/efectos de la radiación , Masculino , Dosis de Radiación , Protección Radiológica , Factores de TiempoRESUMEN
Hemopoiesis was studied in rats after x-ray irradiation. Lethal doses of 800--820 R were applied totally, with screening the shin and with subsequent autotransplantation of bone marrow taken from noninjured hemopoietic tissue. Survival of the animals and status of hemopoietic organs (quantitative indices of the peripheral blood, bone marrow and the spleen, as well as morphological changes in hemopoietic organs) served as tests. All totally irradiated animals died by the 20th day, the 30th day in the group of screened animals 32% survived, in the group with autotransplantation of bone marrow--62%. According to the indices studied restoration of hemopoiesis proceeded more quickly and completely in the group with autotransplantation of bone marrow and somewhat slower in the group with screening the shin (but without autotransplantation); this was accompanied by repopulation of bone marrow comparing with the totally irradiated animals. Restoration of the hemopoietic organs was followed by a comparatively rapid increase in the number of myeloid cells, while the number of lymphoid cells increased more slowly.
Asunto(s)
Trasplante de Médula Ósea , Hematopoyesis/efectos de la radiación , Traumatismos Experimentales por Radiación/patología , Animales , Recuento de Células Sanguíneas , Médula Ósea/efectos de la radiación , Recuento de Células , Traumatismos Experimentales por Radiación/mortalidad , Traumatismos Experimentales por Radiación/terapia , Ratas , Bazo/efectos de la radiación , Factores de Tiempo , Trasplante Autólogo , Rayos XAsunto(s)
Neoplasias Experimentales/radioterapia , Traumatismos Experimentales por Radiación/fisiopatología , Animales , Carcinoma de Ehrlich/radioterapia , Relación Dosis-Respuesta en la Radiación , Femenino , Reacción Huésped-Injerto/efectos de la radiación , Ratones , Trasplante de Neoplasias , Factores de TiempoRESUMEN
It was shown that in X-irradiation of rats in the absolute lethal dose (850 R) shielding of the shank saved 32% of the animals from death. Bone marrow autotransplantation from the shielded portion immediately after the irradiation augmented the shielding effect considerably. Such protective action of autotransplantation persists if conducted in the course of the first 5 days after the irradiation, but it decreases later (on the 7th-10th day).