The recovery of humoral immunity after the long-term action of tritium oxide at different irradiation levels

Dynamics of recovery of humoral immunity of CBA mice was studied 1, 3, 6 and 12 months after termination of long-term exposure to tritium oxide at various levels of absorbed doses (3, 5 and 9 Gy) and dose rates (3.3, 4.9 and 9.2 cGy.day-1). A severer and more stable residual radiation damage was observed in the department of lymphocyte precursors. A considerable decrease in the content of antibody producers was due to the lymphoid tissue hypoplasia. There was a direct relationship between the immunodeficiency and dose rate and total absorbed dose of beta radiation.     

The effects of irradiation at different times of the day on rat intestinal goblet cells

Quantitative changes in jejunal goblet cells were studied in control and whole body irradiated rats using PAS-Alcian blue staining of crypt sections. A circadian dependence was observed when control animals were killed at different times during the light/dark cycle. Irradiation with 3 Gy produced a 2–3-fold increase within 36 h in goblet cells relative to controls, followed by a reduction to very low levels. There was a return to pre-treatment levels later than was observed for the columnar cells. The present results on the pattern of response of goblet cells and those of brush border enzyme activity are consistent with the hypothesis that ionizing radiation can influence differentiation. In fact during the first hours after irradiation an early induction of differentiation is evident while during the early repopulation phase columnar cells prevailed relative to the goblet cells. Only at later times were normal differentiation patterns seen. Groups of animals exposed to the same dose of radiation at different times of the day showed similar general patterns of behaviour even if the group irradiated at midnight showed a more marked and longer lasting injury.     

Involvement of DNA polymerase delta in DNA repair synthesis in human fibroblasts at late times after ultraviolet irradiation

DNA repair synthesis following UV irradiation of confluent human fibroblasts has a biphasic time course with an early phase of rapid nucleotide incorporation and a late phase of much slower nucleotide incorporation. The biphasic nature of this curve suggests that two distinct DNA repair systems may be operative. Previous studies have specifically implicated DNA polymerase delta as the enzyme involved in DNA repair synthesis occurring immediately after UV damage. In this paper, we describe studies of DNA polymerase involvement in DNA repair synthesis in confluent human fibroblasts at late times after UV irradiation. Late UV-induced DNA repair synthesis in both intact and permeable cells was found to be inhibited by aphidicolin, indicating the involvement of one of the aphidicolin-sensitive DNA polymerases, alpha or delta. In permeable cells, the process was further analyzed by using the nucleotide analogue (butylphenyl)-2'-deoxyguanosine 5'-triphosphate, which inhibits DNA polymerase alpha several hundred times more strongly than it inhibits DNA polymerase delta. The (butylphenyl)-2'-deoxyguanosine 5'-triphosphate inhibition curve for late UV-induced repair synthesis was very similar to that for polymerase delta. It appears that repair synthesis at late times after UV irradiation, like repair synthesis at early times, is mediated by DNA polymerase delta.     

Synthesis and protective anti-infective action of anomeric lipophilic glycosides of N-acetylmuramyl-L-alanyl-D-isoglutamine

Anomeric pairs of α-and β-dodecyl, α-and β-(1-pentylhexyl), and α-and β-cyclododecyl glycosides of N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP) were synthesized. The starting β-D-glucosaminides were obtained by the oxazoline method, and the corresponding α-isomers, by the mercuric iodide-catalyzed glycosylation of alcohols with α-glucosaminyl chloride peracetate in nitromethane at ～90°C. No reliable differences between the stimulation of mouse resistance to the infection with Staphylococcus aureus (doses of 2, 20, and 200 μg/mouse) and Escherichia coli (doses of 0.05, 1, and 20 μg/mouse) with the MDP α-and β-glycosides were found.     

The immunity indices of rats after the long-term action of tritium oxide or gamma irradiation

In experiments with Wistar rats, a study was made of the content of antibody-forming cells and cytotoxic activity of normal killers after long-term administration of tritium oxide (3HOH) (370 kBq.g-1 of body mass daily, cumulative dose, 8.1 Gy, and dose rate, 8.5 cGy/day), and after gamma irradiation with corresponding doses. The long-term radiation effect caused a decrease in the immunity indices: the impairment of the immune reactions was more pronounced after the effect of 3HOH than after gamma irradiation. Damages to the immune system of mice and rats after irradiation with similar doses were compared.     

Synthesis and protective anti-infective action of anomeric lipophilic glycosides of N-acetylmuramyl-L-alanyl-D-isoglutamine

Anomeric pairs of alpha- and beta-dodecyl, alpha- and beta-(1-pentylhexyl), and alpha- and beta-cyclododecyl glycosides of N-acetylmuramyl-L-alanyl-D-isoglutamine (MDP) were synthesized. The starting beta-D-glucosaminides were obtained by the oxazoline method, and the corresponding alpha-isomers, by the mercuric iodide-catalyzed glycosylation of alcohols with alpha-glucosaminyl chloride peracetate in nitromethane at -90 degrees C. No reliable differences between the stimulation of mouse resistance to the infection with Staphylococcus aureus (doses of 2, 20, and 200 microg/mouse) and Escherichia coli (doses of 0.05, 1, and 20 microg/mouse) with the MDP alpha- and beta-glycosides were found.     

Cytogenetical indices in remote times after acute irradiation of people. The computer method of retrospective dose estimation

The computer method of retrospective dose estimation is used for the reconstruction of dose irradiation of victims in the result of Chernobyl accident by the results of repeated cytogenetical investigations in remote time after exposure. This method is based on the analysis of cell distributions in accordance with the number dicentrics and with unstable chromosome aberrations contained in them by special computer program. Received data demonstrate that for more exact reconstruction of original absorbed doses the need additional correction taking into account time after irradiation or frequencies of atypical chromosomes ensued from account of chromosome aberrations in remote time after exposure is needed.     

Circadian rhythms of 11-hydroxycorticosteroid excretion in rats administered cortisol at different times of the day

Male Wistar rats housed under the conditions of 12L : 12D, 24 +/- 1 degree C and free access to food and water received isotonic sodium chloride solution or cortisol in doses of 2 and 4 mg/kg, respectively. Daily stress or cortisol injections in the morning or evening are the synchronizers of 11-hydroxycorticosteroid excretion rhythm. Morning stress leads to the increase of the 12-hour rhythm. On the contrary, evening stress or cortisol administration during maximal endogenous secretion of corticosteroids are associated with the elevation of circadian periodicity. Exogenic changes in the rhythmic organization of the hypothalamo-hypophyseal-adrenocortical system are followed by activation of adaptive processes involved in the normalization of the initially modified glucocorticoid rhythm.     

Ceruloplasmin serum level in post-menopausal women treated with oral estrogens administered at different times.

The liver is an estrogen-responsive organ and the administration of estrogens in humans increases the hepatic synthesis of many proteins. The existence of a circadian rhythm of estrogen receptors in the liver has been proved by different authors. We studied the presence of a different responsiveness of the human liver to the estrogens in two groups of post-menopausal women by evaluating the changes in ceruloplasmin serum level. Conjugated equine estrogens were administered at different times (A: 8 a.m. and B: 8 p.m.). The replacement therapy increased ceruloplasmin serum levels both in group A and B, but the increase was higher in group B than in group A. These data reflect indirectly the presence of a circadian rhythm of hepatic responsiveness to the estrogens.     

The effects of spermatozoal irradiation with X-rays on chromosome abnormalities and on development of mouse zygotes after delayed fertilization

The chromosome complements of zygotes derived from oocytes aged post ovulation and fertilized in vivo with X-ray-irradiated sperm were studied. Ovulation was induced by an injection of luteinizing hormone-releasing hormone (LHRH) at pro-estrus and fertilization was achieved by artificial insemination at 13 h and 24 h after LHRH in order to obtain embryos from unaged and aged (12 h post-ovulation) oocytes respectively. Post-ovulatory aging prior to fertilization did not significantly affect the percentage of zygotes with irradiation-induced chromosome abnormalities. However, post-ovulatory aging had a negative effect on the morphology of male as well as female pronuclear chromosomes of the first cleavage metaphase. When fertilized with control spermatozoa this effect was apparent in both the male and the female pronucleus. When unaged oocytes were fertilized with X-irradiated spermatozoa chromosome morphology was also adversely affected in both pronuclei. In zygotes from aged oocytes, there was an extra negative effect of X-rays on the male pronuclear chromosomes only. After fertilization with X-irradiated sperm 27% of zygotes from aged oocytes were arrested at interphase compared to 7% from unaged oocytes. We suggest that post-ovulatory aging and X-rays affect the male and female pronuclear chromatin structure after fertilization. These chromatin alterations could interact with DNA lesions induced in the spermatozoa prior to fertilization, such that development to first cleavage can be blocked.     

Combination of chemotherapy and radiotherapy. II. Differential effect on the medullary syndrome of irradiation combined with the drug administered in fractional doses and at various times]

We have studied the effect of 5-Fu in fractional doses on the medullar syndrome after a single whole body cobalt irradiation in mice. The bone marrow is not sensitive to the fractionation of 5-Fu and it is the single dose of 5-Fu injected 72 hours after the irradiation which is the most effective.     

Combination of chemotherapy and radiotherapy. I. Differential effect on the intestinal syndrome of irradiation combined with the drug administered in fractional doses and at various times]

We have studied the different effects on the intestinal syndrome between the administration of fractional doses of 5-Fu before and after irradiation. There is no difference between the diverse modalities and we obtain the same result when the 5-Fu is administered, fractionated or not, before or after the irradiation.     

The dynamics of the extinction of brain cellular biosynthesis at different times after death]

The paper presents experimental data on RNA synthesis in neuronal, glial, endothelial cells of a dying organism. Under certain conditions it is possible to define labelled cells in the majority of the brain cells within post-death hours 1-4. This fact proves that genome is still functioning. Endothelial cells possess higher vital capacity. CNS neurons are capable of synthesizing RNA within the period of up to 4 hours after death of the organism.     

New data on the biological action of normal immunoglobulins

Experiments on 2,520 CBA mice (CBA X X C57BL) F1 nice have shown that the injection of homologous serum immunoglobulins (obtained from intact and blood-stimulated animals), made 2 hours after gamma irradiation from a 60Co source, prevents the development of intestinal dysbacteriosis and endogenous infection. The injection of mouse and human immunoglobulins to nonirradiated mice improved their resistance to experimental infection with Escherichia coli live culture, increased the expression of receptors to the Fc-fragments of IgG in peritoneal macrophages and enhanced the physical working capacity of the animals. The preparations containing normal antitissular antibodies have proved to be particularly effective. In mice, rabbits and dogs the preparations under test have produced no changes in the general state of the animals, no local reactions and no disturbances in the cardiovascular activity.