摘要:

An investigation was done to assess the effect of a single intraperitoneal (ip) injection of thioacetamide on the incorporation of [3H]TdR into DNA of 13 different tissues and on the mitotic index of the corneal epithelium of mice. Seven-week-old CD2F1mice, who had been standardized to 12 hours (hr) of light alternating with 12 hr of darkness, and fedad libitumwere used. The experimental design took into consideration the circadian variation that characterizes cell proliferation in all of the tissues studied. This was done by killing subgroups of seven animals every 6hr for 96 hr. Thirty minutes prior to killing all mice were injected ip with 25μCi of [3H]-thymidine and its incorporation into DNA was determined. The tissues of all thioacetamide and saline treated mice showed marked circadian variation in DNA synthesis. Thioacetamide treatment brought about significant (P<0.05) stimulation of DNA synthesis in the liver and kidney thus confirming, but extending an earlier finding. Moreover, the data showed for the first time that DNA synthesis in the bone marrow and spleen and colon were markedly statistically significantly stimulated at specific times after treatment. Synthesis of DNA in the thymus, lung, testes, tongue, esophagus, duodenum, rectum and the mitotic index in the corneal epithelium were not statistically significantly altered by thioacetamide treatment.A preliminary study also was carried out to explore what effect multiple treatment with epidermal growth factor (EGF) had on DNA synthesis in thioacetamide treated mice. Mice were killed 36 hr after thioacetamide treatment, but were treated with EGF which began 15 hr after the thioacetamide was administered and this was repeated at 18, 21 and 24 hr (50μg/mouse/treatment). Under the conditions of this study EGF significantly (P<0.05) depressed DNA synthesis 76% in the liver, 64% in the thymus, 22% in the spleen, 30% in the duodenum and 24% in the esophagus. A histological analysis of the livers of four EGF treated and four non-EGF treated mice was done, but no consistent differences in terms of necrosis, inflammation or regeneration were observed between the two groups.

ISSN:0742-0528    

DOI:10.3109/07420528609083154

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

Lithium has been shown to lengthen free-running circadian periods in a variety of species. Here we show that lithium carbonate differentially lengthens the free-running period of a circadian wheel running rhythm in BALB/CByJ and C57BL/10Sn inbred mouse strains. This result supports previous evidence that lithium lengthens mammalian circadian rhythms, and also demonstrates that gene differences can mediate individual differences in response to lithium treatment.

ISSN:0742-0528    

DOI:10.3109/07420528609083155

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

The temporal variation in the migration of polymorphonuclear leukocytes (PMN) induced by live BCG was studied in the mouse. Tenμl of a 5±106live BCG/ml suspension or sterile saline were placed on a cell trap immediately before its subcutaneous implantation at different clock times: 0100, 0500, 0900, 1300, 1700 and 2100 in animals synchronized with L(0700-1900): D(1900-0700). Eight hours later, the cell trap was removed, prepared for histological identification and counted. PMN counts in the cell trap were maximal 480 min after implantation. Nonspecific migration was thought to occur and the peak value of leukocytes of 22.8±6.1 cells/10,000μm2was obtained when the saline cell-trap was implanted at 0500. In the BCG-treated mice, a circadian rhythm was observed in the migration of leukocytes. The acrophase was at 1700. The results support the hypothesis that the circadian stage of antigen encounter influences the magnitude of the immune response.

ISSN:0742-0528    

DOI:10.3109/07420528609083156

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

In this paper circadian changes in the liver enzyme activities of rat housed under highly standardized conditions with 12:12 hour light-dark cycle are shown. Activities of acid phosphatase, arylsulphatase,β-galactosidase andβ-N-acetyl-d-glucosaminidase in microsomal and lysosomal fractions and crude homogenate were estimated every 4 hr during one 24-hr period. The enzyme activities were related to 1 mg of protein, 1 mg of DNA and 1 g fresh tissue. Daily changes of enzyme activities were found. In case of activity calculated per 1 mg DNA two maxima at 0500 and at 2100 hr were observed, while activity calculated per 1 mg protein showed one maximum at 0500 hr. Activity calculated per 1 g fresh tissue showed the maximum at 0500 hr for each enzyme only in microsomal fraction. As far as acrophase table is concerned for all enzymes and fractions the acrophase occurred during the night. The obtained results are discussed in relation to lysosomal enzymes synthesis process as well as different reference values.

ISSN:0742-0528    

DOI:10.3109/07420528609083157

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

Activity rhythms of enzymes were determined in various tissues of C57BL/6J male mice. The determinations were carried out on mice which were kept in 14 hr light: 10 hr dark regimen, and on day 2, day 5 and day 21 during exposure to continuous illumination. Locomotor activity rhythms were followed in light: dark and up to the seventh day in constant light. All the activities exhibited a significant circadian rhythm in the light: dark regimen. During the exposure to continuous illumination, the locomotor activity exhibit a free running circadian rhythm with a consistent 24 hr and 40 min, major period component. At the same time recording the rhythms of enzyme activity; enzymes exhibited various formats of response which differed from those of the locomotor activity. The results suggest that rhythms of enzyme activity, as well as the desynchronization of the rhythms, are not enzyme specific.

ISSN:0742-0528    

DOI:10.3109/07420528609083158

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

The complete hematologic blood cell count of 11 patients with advanced cancer were determined on 14 occasions, every 4 hr over 36-48 hr. Oral temperature was also measured at the same times as blood sampling. Five patients had breast cancer, five had ovarian cancer and one a leiomyosarcoma. Circadian rhythms were detected by the cosinor method for seven hematologic variables (red blood cells, hemoglobin, hematocrit, white blood cells, neutrophils, lymphocytes, platelets) and for oral temperature in the whole group of patients. All acrophases were located between 1300 and 1700 hr, except for lymphocytes (2100 hr). A rhythm with a period of 8 hr was validated for lymphocytes and monocytes. Validated or estimated amplitudes and acrophases were closely similar in both breast and ovarian cancer subgroups. Individual cosinor analyses documented large differences from patient to patient, which were accounted for by differences in performance status. Thus, subjects with poor performance status and rapidly progressive disease had very few validated rhythms as compared to those patients with good performance status. As a result a statistically significant correlation was found between the number of validated hematologic circadian rhythms and the performance status (r= -0.88;P<0.01).

ISSN:0742-0528    

DOI:10.3109/07420528609083159

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

Cisplatin-induced mortality and nephrotoxicity are each predictably worse when the drug is given at certain points within the circadian schedule. Oral disulfiram protects rats from toxic effects at some circadian stages but not others. This manuever does not diminish the anticancer activity of cisplatin in these rats. Human beings given 2 g of oral disulfiram and high doses of cisplatin at the circadian stage associated with least cisplatin nephrotoxicity (prospectively determined potassium excretion acrophase) suffer little or no kidney damage. Disulfiram administration apparently does not interfere with the antineoplastic activity of cisplatin in humans. This is the first demonstration of the feasibility of assignment of treatment time according to a measure of the patient's‘internal clock’as assessed by pretreatment marker rhythmometry. It also establishes the feasibility of giving disulfiram to human beings.

ISSN:0742-0528    

DOI:10.3109/07420528609083160

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

The authors took a series of 20 serum samples over a 24-hr period for measurement or melatonin in four men and six women with Major Depressive Disorder (DSM-III), at baseline (depressed) and after 4 weeks on imipramine (150-200 mg/day) after achieving clinical remission. After successful treatment with imipramine, 24-hr secretion and peak levels of melatonin were significantly higher than at baseline, with no difference in time of peak level. Testing after 2 weeks of treatment (four subjects), with only a partial or no clinical response, revealed no differences compared with baseline. The therapeutic efficacy of imipramine may be associated with an enhancement of noradrenergic activity.

ISSN:0742-0528    

DOI:10.3109/07420528609083161

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

In the flesh-fly,Sarcophaga argyrostoma, the initiation of larval wandering, pupal eclosion, and the induction of pupal diapause by seasonal changes in night length, are all regulated by circadian oscillators. They differ, however, in several respects. The rhythm of larval wandering shows a free-running period (S) of about 20 hr and a steady-state phase-relationship to the light cycle (±) in which maximum activity occurs at dusk or in the night; that for pupal eclosion shows±close to 24 hr and±close to dawn; and that for diapause induction±longer than 24 hr and a photoinducible phase (ϕi) late in the subjective night. The three oscillators are, therefore, considered to be functionally separate. In addition, adult locomotor activity, the deposition of cuticular growth layers on thoracic apodemes, and the duration of larval wandering, are possibly regulated by further, distinct, oscillators. The circadian system inS. argyrostoma, therefore, contains at least three, and probably as many as six, known circadian pacemakers.

ISSN:0742-0528    

DOI:10.3109/07420528609083162

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

ISSN:0742-0528    

DOI:10.3109/07420528609083163

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor