Circadian Hematologic Time Structure in the Elderly

Twenty-three clinically healthy, diurnally active elderly subjects, 71 ± 5 years of age were studied over a 24-hr span (six samples). Complete blood counts and differential counts were done (Ortho ELT-8, Wright stained smears). The circadian rhythm parameters of the hematologic variables in the elderly subjects were compared with reference values obtained from a larger group of clinically healthy young adult and adult subjects studied independently. The data were analyzed by cosinor and the Bingham test. Circadian rhythms in the number of circulating formed elements in the peripheral blood persist in the aged. In comparison with the young adult, the elderly subjects show differences in the timing (phase advance) of the circadian rhythms in circulating neutrophil leukocytes and lymphocytes, a decrease in the circadian amplitude of circulating platelets, a decrease in circadian rhythm adjusted mean (mesor) in the red cell count, and in the neutrophil band forms.     

Interindividual differences in the circadian hematologic time structure of cancer patients

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 less than 0.01).     

Ultradian, circadian and seasonal variations of plasma progesterone and LH concentrations during the luteal phase

The circadian variations in plasma progesterone (P) and LH concentrations were investigated in six women, aged 23-40 years. All were studied in the mid-luteal phase (7 +/- 2 days after LH mid-cycle surge). Experiments were conducted in autumn and in spring. Blood samples were obtained every 15 min for 24 hr. Plasma P and LH concentrations were measured by RIA. Each subject's time-series was analysed using three methods; visual inspection (chronogram), spectral analysis to estimate component periods of rhythms (tau) and cosinor analysis to quantify the rhythms parameters. Marked temporal variations in plasma P concentration were observed in each subject. The maximal variations over a 24-hr period, ranged between 13-58.5 mmol/l. Differences related to sampling time were statistically validated by ANOVA (p less than 0.00001). Significant harmonic periods were detected by spectral analysis but differed among subjects. In all subjects but one, a circadian rhythm was detected. The acrophase location was similar (about 0700 hr) in the four subjects studied in autumn, but ranged from 1940 to 0320 hr in those studied in spring. An ultradian rhythm with tau = 8 hr was also validated in six time-series with similar acrophases (about 0200, 1000, and 1800 hr). Cosinor analysis of pooled data revealed that the 24-hr, 12-hr, and 8-hr rhythms were statistically significant (p = 0.001) in autumn. algebraic sum of these three cosine functions yielded a circadian waveform with peak-times occurring near 0300 and 1130 hr and a trough-time about 2200 hr. In spring, the circadian pattern appeared quite different, and peak-times were found near 0700 and 2000 hr, and trough-times near 0300 and 1500 hr. Furthermore, the 24-hr mean of P was higher in autumn (28.9 +/- 0.4 nmol/l) than in spring (17.2 +/- 0.4 nmol/l), p from ANOVA less than 0.00001. The evidence for a similar circadian LH pattern is not as strong. Seasonal, circadian and ultradian rhythms characterize the physiologic time structure of plasma P concentration in mid-luteal phase.     

Are There Circadian Variations of Polymorphonuclear Phagocytosis in Man?

Eleven male subjects were investigated to detect a possible circadian rhythm of the polymorphonuclear phagocytosis. Both cell activity and serum opsonins were studied for numerical detection of granulocytes having ingested at least one particle and for the mean number of ingested particles per cell. No significant temporal differences (ANOVA and cosinor) were found.     

Circadian Response of Annual Weeds in a Natural Setting to High and Low Application Rates of Four Herbicides with Different Modes of Action

Four herbicides [glyphosate (GLYT), an amino acid synthesis inhibitor; glufosinate (GLUF), a glutamine synthetase inhibitor; fomesafen (FOME), a protoporphyrinogen oxidase inhibitor; and chlorimuron ethyl (CLIM), an acetolactate synthase inhibitor] were used to examine the influence of time of day of application on the control of a variety of annual broadleaf weeds in field studies conducted in Minnesota (five studies on GLYT and GLUF, three studies on FOME and CLIM). All herbicides were applied with an adjuvant at recommended high and low (half or quarter strength) rates every 3h between 06:00 and 24:00h local time. Visual ratings of percent weed control evaluated at 14d were analyzed by herbicide and application rate for each study and across studies for time-of-day effect by analysis of variance (ANOVA) and single cosinor. A circadian response to each herbicide was found, with greatest weed control observed between 09:00 and 18:00h. Increasing the herbicide application rate did not overcome the time-of-day effect (ANOVA: p≤0.008 for time-of-day effect for each herbicide and application rate). The least-squares fit of a 24h cosine was significant (p≤0.001) for each herbicide and application rate, with double amplitudes of 18–82% (units=% visual control) and estimated peaks (acrophases) near midday between 12:40 and 13:35h. Analysis of residuals obtained from multiple regression that included weed height, herbicide rate, temperature, and relative humidity as independent factors also found a significant time-effect by both ANOVA and cosinor for each herbicide and rate, with acrophases advancing significantly by 3 to 7h for GLYT and GLUF, but not for FOME or CLIM. These results suggest that the four herbicides, while belonging to different families with different modes of action, may reveal different peak times of efficacy when adjusting for environmental factors. Nonetheless, each displays similar circadian patterns when influenced by these factors under natural seasonal field conditions. The within-day rhythmic differences found in weed control are large enough to warrant consideration of the practical financial and environmental importance of the time-of-day that these and other herbicides are applied.     

Rhythms in the ovulatory cycle. 2nd: LH, FSH, estradiol and progesterone

The circadian profiles of LH, FSH, estradiol and progesterone were compared in a homogeneous group of 15 young normally cycling women, at 4 well characterized times of the menstrual cycle: early follicular (EF), late follicular (LF), early luteal (EL) and late luteal (LL) stages. The circatrigintan profiles of the same hormones were also evaluated. Population-mean cosinor analysis failed to demonstrate a circadian periodicity of LH in any of the 4 stages of the menstrual cycle; a circadian rhythm for FSH was present only in the 2 luteal phases (EL, LL); the same type of rhythmicity was present for estradiol only in the late luteal stage; on the contrary, a highly significant circadian rhythm of progesterone was present in each of the 4 menstrual stages considered (EF, LF, EL and LL). Population-mean cosinor analysis showed a highly significant circatrigintan periodicity of LH and FSH with the acrophases respectively between -109 degrees and -181 degrees and between -74 degrees and -125 degrees. Circatrigintan rhythmicity was also present for estradiol (acrophases between -161 degrees and -245 degrees) and progesterone (acrophases between -246 degrees and -296 degrees).     

Circadian Rhythm of Blood Pressure and Heart Rate in Healthy Persons and Kidney Transplant Patients: Correlations with Activity

Fourteen diurnally active (07: 00–22: 39 h) normotensive healthy control subjects and 14 kidney transplant patients were studied by ambulatory blood pressure monitoring and wrist actigraphy simultaneously during one 24-h period. In the control group, circadian rhythms in systolic (SBP), diastolic (DBP), and mean arterial (MAP) blood pressure, heart rate (HR), and wrist activity were documented by cosinor analysis with comparable afternoon peak times. In contrast, circadian rhythms with afternoon acrophases were detected only in HR and wrist activity in the patient group. The correlation of wrist activity with HR in controls and patients was comparable. Wrist activity and blood pressure were associated (r = 0.65 DBP and 0.54 SBP; p < 0.05) in controls, while in patients the relationship was weak or absent (r ranging from 0.02 SBP to 0.22 DBP). In 6 of 14 patients, BP and wrist activity were negatively correlated, reflecting the existence of nocturnal hypertension. In eight others, the correlation was small but positive. The 24-h pattern in BP and wrist activity in controls was comparably phased; however, this was not the case for the transplant patients, indicating the day-night pattern in blood pressure in this group is strongly dependent on pathologic phenomena rather than activity level and pattern.     

Circadian Rhythms of Serum Concentrations of 12 Enzymes of Clinical Interest

A total of 25 apparently healthy adults (13 men and 12 women), 29.5 years (SD = 3.6 years) of age, served as subjects in a 24-h study conducted in Barcelona, Spain, in the spring of 1990. The group had a homogeneous pattern of meals, activity, and behavior. Six blood samples were collected at 4-h intervals over a single 24-h period beginning at 10:00 h. The oral temperature was measured at 2-h intervals to facilitate an independent biological time reference for the local population being studied. The serum concentration of 12 enzymes of clinical interest were measured in each sample: creatine kinase, creatine kinase 2, alanine aminotransferase, aspartate aminotransferase, γ-glutamyltransferase, alkaline phosphatase, cholinesterase, lactate dehydrogenase, lactate dehydrogenase 1, 5′-nucleotidase, pancreatic α-amylase, and triacylglycerol lipase. We supposed that all experimental data obtained for a quantity came from a single “hypothetical subject” that represented the central tendency of the population and then these data were analyzed for circadian rhythm by single cosinor. A statistically significant circadian rhythm was detected in all quantities studied (p ≤ 0.05) except for serum concentrations of pancreatic α-amylase and triacylglycerol lipase. The maximum daily rhythmic variation was ～ 10% (interval, 6–14%) for all quantities studied except pancreatic α-amylase (2.6%). This rhythmic variation is greater than the analytical variation except for 5′-nucleotidase and pancreatic α-amylase. The acrophases for the quantities studied (except that of triacylglycerol lipase) coincide with times near those of the oral temperature acrophase (18:01 local time). The results of this study will doubtless contribute to further documentation of the structure of the human circadian timing system and to establishment of time-qualified reference intervals for a defined group of subjects.     

Circadian rhythm in murine reticuloendothelial function

Six separate groups, each composed of 15 comparable inbred female CBA mice, standardized in light daily from 0700 to 1900, alternating with darkness, maintained with food and water available ad libitum, were tested at 4-h intervals for a 24-h span for the phagocytic index, determined 3, 6, 9 and 12 min after the injection of a carbon suspension. By an analysis of variance and the single cosinor method applied to these data a circadian rhythm was demonstrated, with a double amplitude of 20% and an acrophase during the second half of the daily light span. These results extend the scope of immunologic circadian rhythms to the reticuloendothelial system as a feature of a bioperiodic defense mechanism, most active during the habitual rest light span of nocturnally active mice.     

Evaluation of the circadian profile of peripheral plasma galanin concentrations in normal subjects

Galanin administration can influence pituitary function principally resulting in an increase in GH secretion. However, the role of circulating GAL levels in human endocrine function is still unknown. In the present study we simultaneously measured the circadian profiles of GAL, ACTH and GH in peripheral blood of ten adult subjects. Plasma samples were collected through an intravenous catheter at 0800, 1200, 1600, 2000, 2200, 2400, 0200, 0400 hours. The results were statistically evaluated by the cosinor analysis technique. A significant circadian rhythm of both plasma ACTH (p < 0.001) and GH levels (p < 0.03) was found with acrophases occurring at 0753 hrs and 0131 hrs for ACTH and GH, respectively. On the contrary, no significant rhythm was found in plasma GAL levels, indicating that no correlations exist between GAL and either GH or ACTH circadian profiles. Furthermore, the simultaneous assay of both GAL and GH plasma levels during a nocturnal frequent sampling performed in four volunteers showed the presence of peaks in GAL levels which, however, were not concomitant to the peaks in GH levels. These data demonstrate the lack of rhythmicity in the circadian profile of plasma GAL levels in healthy human subjects. The role of GAL in human endocrine function remains unknown and these results suggest that, in spite of the well documented increase in plasma GH concentrations following the intravenous administration of GAL, physiologically circulating levels of GAL are likely not involved in the regulation of GH secretion.     

Circadian rhythms of adrenaline and noradrenaline excretion in man in normal conditions and after alcohol intake

Circadian rhythms of adrenaline and noradrenaline excretion with urine in health and during 3 days after a single intake of 40 degrees alcohol from 5 to 6 p.m. in a dose of 6.2 ml/kg bw were examined in 20 healthy male volunteers aged 20 to 26 years, in spring. The data obtained were processed according to the "cosinor" program. Alcohol intake resulted in the tension of the sympathoadrenal system, with that tension being observed over 2 days and not removed after ethanol elimination. Circadian rhythms of catecholamine excretion essentially changed. Within the first day after alcohol intake, mesor and rhythm amplitudes increased, acrophases displaced for a time following alcoholization. By the second day the increase of the mesors was preserved, the acrophases returned to normal. Complete recovery of the normal circadian time structure took place during the third circadian cycle after alcohol intake.     

Comparative study of circadian variation in oral,tympanic, forehead,axillary and elbow pit temperatures measured in a cohort of young university students living their normal routines

The primary objective of the present research work is to study and compare the circadian variability in body temperature recorded from different locations of the body during subjects’ normal routines. Temperatures of oral cavity (sublingually), tympanum, forehead, axilla and the elbow pit were measured simultaneously at approximate 1-h intervals for five consecutive days during subjects’ waking span in their routine living condition. The observations were made in eight young, apparently healthy, university students. Data were analysed using cosinor rhythmometry for evaluation of circadian rhythms and two-way ANOVA with repeated measures to assess the effect of time of day and measuring site on body temperatures and their interaction. Significant circadian rhythms in body temperature, irrespective of site, were found. Based on autocorrelation analysis, it was observed that the day-to-day variability in body temperature was consistent. The acrophases of all the studied temperature rhythms were located in the afternoon, except axillary temperature, which occurred in the early evening. The mean daytime temperature was found to be the highest when recorded sublingually and it was the lowest on the forehead or elbow pit. On the basis of the results of this study, we recommend that the methods used could be introduced into laboratory courses in a curriculum of chronobiology courses for both UG and PG classes for the demonstration/study of circadian rhythms in body temperature under normal routines. The methods used are valuable as they are non-invasive, easily accepted and assessable in a student setting.     

Melatonin supplementation decreases prolactin synthesis and release in rat adenohypophysis: correlation with anterior pituitary redox state and circadian clock mechanisms

In the laboratory rat, a number of physiological parameters display seasonal changes even under constant conditions of temperature, lighting, and food availability. Since there is evidence that prolactin (PRL) is, among the endocrine signals, a major mediator of seasonal adaptations, the authors aimed to examine whether melatonin administration in drinking water resembling in length the exposure to a winter photoperiod could affect accordingly the 24-h pattern of PRL synthesis and release and some of their anterior pituitary redox state and circadian clock modulatory mechanisms. Melatonin (3?μg/mL drinking water) or vehicle was given for 1 mo, and rats were euthanized at six time intervals during a 24-h cycle. High concentrations of melatonin (>2000 pg/mL) were detected in melatonin-treated rats from beginning of scotophase (at 21:00?h) to early photophase (at 09:00?h) as compared with a considerably narrower high-melatonin phase observed in controls. By cosinor analysis, melatonin-treated rats had significantly decreased MESOR (24-h time-series average) values of anterior pituitary PRL gene expression and circulating PRL, with acrophases (peak time) located in the middle of the scotophase, as in the control group. Melatonin treatment disrupted the 24-h pattern of anterior pituitary gene expression of nitric oxide synthase (NOS)-1 and -2, heme oxygenase-1 and -2, glutathione peroxidase, glutathione reductase, Cu/Zn- and Mn-superoxide dismutase, and catalase by shifting their acrophases to early/middle scotophase or amplifying the maxima. Only the inhibitory effect of melatonin on pituitary NOS-2 gene expression correlated temporally with inhibition of PRL production. Gene expression of metallothionein-1 and -3 showed maxima at early/middle photophase after melatonin treatment. The 24-h pattern of anterior pituitary lipid peroxidation did not vary after treatment. In vehicle-treated rats, Clock and Bmal1 expression peaked in the anterior pituitary at middle scotophase, whereas that of Per1 and Per2 and of Cry1 and Cry2 peaked at the middle and late photophase, respectively. Treatment with melatonin raised mean expression of anterior pituitary Per2, Cry1, and Cry2. In the case of Per1, decreased MESOR was observed, although the single significant difference found between the experimental groups when analyzed at individual time intervals was increase at early scotophase in the anterior pituitary of melatonin-treated rats. Melatonin significantly phase-delayed expression of Per1, Per2, and Cry1, also phase-delayed the plasma corticosterone circadian rhythm, and increased the amplitude of plasma corticosterone and thyrotropin rhythms. The results indicate that under prolonged duration of a daily melatonin signal, rat anterior pituitary PRL synthesis and release are depressed, together with significant changes in the redox and circadian mechanisms controlling them. (Author correspondence: danielcardinali@uca.edu.ar ; danielcardinali@fibertel.com.ar ).     

Circadian and/or circahemidian rhythms in nine lymphocyte-related variables from peripheral blood of healthy subjects

Circadian variations were investigated for nine lymphocyte-related variables in the peripheral blood of healthy subjects. Monoclonal antibodies targeted at membrane immunoglobulins (anti-Ig, anti-kappa, anti-lambda) or differentiation antigens (anti-IA and OKT3) were used to characterize respectively mature B cells (SIg+, kappa +, lambda +), cells expressing HLA-DR antigen (IA+), and T cells (OKT3+). Blood (33 ml) was drawn every 4 hr for 24 hr starting at 8.30 hr, on seven occasions in five apparently healthy male volunteers, recumbent from 23.00 hr to 07.00 hr. Leukocyte and differential counts were measured. Mononuclear cells were isolated on Ficoll-Hypaque before being incubated with monoclonal antibodies. The proportion of fluorescent cells per 100 microscopically determined cells was multiplied by the number of circulating lymphocytes per milliliter of venous blood. Temporal variations were validated by both paired t-test and cosinor. Rhythms with a period (tau) identical to 24 hr were validated with statistical significance (p less than 0.05) for total lymphocytes, OKT3+ cells and OKT3+:SIg+ ratio, and suggested (0.05 less than or equal to p less than or equal to 0.10) for lambda + and (kappa + + lambda +) cells. Rhythms with tau identical to 12 hr were also found (p less than 0.05) for OKT3+, SIg+, kappa +, and IA+ cells as well as for the OKT3+:SIg+ and the kappa +:lambda + ratios. Validated rhythms exhibited a large amplitude, e.g., peak-through differences were 40% of the 24-hr mean. This circadian and circahemidian temporal structure of immunologic variables constitutes a time-qualified reference system for investigating immune regulations and a tool for optimizing both diagnostic criteria and effectiveness of immunotherapeutic attempts.     

Circadian response of annual weeds in a natural setting to high and low application rates of four herbicides with different modes of actions

Four herbicides [glyphosate (GLYT), an amino acid synthesis inhibitor; glufosinate (GLUF), a glutamine synthetase inhibitor; fomesafen (FOME), a protoporphyrinogen oxidase inhibitor; and chlorimuron ethyl (CLIM), an acetolactate synthase inhibitor] were used to examine the influence of time of day of application on the control of a variety of annual broadleaf weeds in field studies conducted in Minnesota (five studies on GLYT and GLUF, three studies on FOME and CLIM). All herbicides were applied with an adjuvant at recommended high and low (half or quarter strength) rates every 3h between 06:00 and 24:00h local time. Visual ratings of percent weed control evaluated at 14d were analyzed by herbicide and application rate for each study and across studies for time-of-day effect by analysis of variance (ANOVA) and single cosinor. A circadian response to each herbicide was found, with greatest weed control observed between 09:00 and 18:00h. Increasing the herbicide application rate did not overcome the time-of-day effect (ANOVA: p≤0.008 for time-of-day effect for each herbicide and application rate). The least-squares fit of a 24h cosine was significant (p≤0.001) for each herbicide and application rate, with double amplitudes of 18-82% (units=% visual control) and estimated peaks (acrophases) near midday between 12:40 and 13:35h. Analysis of residuals obtained from multiple regression that included weed height, herbicide rate, temperature, and relative humidity as independent factors also found a significant time-effect by both ANOVA and cosinor for each herbicide and rate, with acrophases advancing significantly by 3 to 7h for GLYT and GLUF, but not for FOME or CLIM. These results suggest that the four herbicides, while belonging to different families with different modes of action, may reveal different peak times of efficacy when adjusting for environmental factors. Nonetheless, each displays similar circadian patterns when influenced by these factors under natural seasonal field conditions. The within-day rhythmic differences found in weed control are large enough to warrant consideration of the practical financial and environmental importance of the time-of-day that these and other herbicides are applied.     

Zymosan-induced luminol-dependent chemiluminescence response of circulating and extravasated leukocytes in experimental sepsis

This study examines a concurrent profiling of circulating and extravasated polymorphonuclear leukocytes (PMNs) in a rat model of experimental sepsis. Fecal peritonitis was induced in Wistar male rats by intraperitoneal instillation of a fecal suspension in saline (1:1 w/v). Blood and peritoneal fluid were collected 8 h following fecal inoculation for the evaluation of inflammatory response of PMNs using zymosan-induced luminol-dependent chemiluminescence. Fifty microliters of pre-diluted blood or peritoneal fluid samples were mixed with 150 microl of reaction mixture (4 x 10(-4) M luminol+50 microg opsonized zymosan+0.1% gelatin in Hank's balanced salt solution) and the chemiluminescence signal was measured in a luminometer at 37 degrees C. Fecal peritonitis caused a significant leukocytopenia (3540+/-297 mm(-3) versus control value of 7525+/-711 mm(-3), p < 0.001) accompanied by massive infiltration of PMNs in the peritoneal cavity (34700+/-4006 versus 7325+/-425 mm(-3), p < 0.001). The phagocytic activity of circulating blood PMNs was down-regulated whereas a significant up-regulation was observed in the activity of PMNs from peritoneal fluid. In conclusion, this study clearly demonstrates sepsis-induced alterations in both blood and peritoneal fluid PMNs and their quantitative assessment may be helpful in disease evaluation and designing effective therapies.     

Effect of fluconazole on phagocytic response of polymorphonuclear leukocytes in a rat model of acute sepsis

Recently, fluconazole (FLZ) has been shown to improve survival and reduce multiorgan failure in experimental and clinical septic shock. The mechanism by which FLZ affords protection against sepsis remains obscure. This study examines the effect of FLZ on phagocytic activity of polymorphonuclear leukocytes (PMNs) in a rat model of septic shock by inducing fecal peritonitis in male Wistar rats using intraperitoneal instillation (1 mL/kg) of fecal suspension in saline (1:1 w/v). Sham control rats received sterile fecal suspension and vehicle treatment. FLZ was administered in the doses of 0, 3, 10, and 30 mg/kg by gavage 30 minutes before fecal instillation. The samples of peritoneal fluid were collected 8 hours following fecal inoculation for the evaluation of phagocytic response of PMNs using zymosan-induced luminol-dependent chemiluminescence (CL). Fecal peritonitis caused massive infiltration of PMNs in the peritoneal cavity (ANOVA F(4,45) = 6.322, P < .001). Although FLZ reduced the infiltration of PMNs, this effect was neither significant nor dose dependent. The actual CL response was significantly higher in the peritoneal fluid of rats subjected to peritonitis, which was significantly and dose dependently attenuated by FLZ treatment (ANOVA F(4,45) = 11.048, P < .001). Normalization of CL response for 1000 PMNs revealed that FLZ dose-dependently albeit insignificantly reduced the activity of PMNs. The high dose of FLZ caused 2.29-fold decrement in the area under curve (AUC) pertaining to cumulative CL response. The findings of this study suggest that FLZ protects rats against septic shock by inhibiting PMN-mediated inflammatory cascade without compromising their phagocytic activity.     

Circadian rhythms in surface molecules of rat blood lymphocytes

The present article examines whether the expression of certain surface molecules that trigger immune responses shows a circadian rhythm. We also analyzed the rhythms in the number and percentage of lymphocyte subpopulations, in the leukocyte differential counts, and in the total red and white blood cell counts. Blood samples obtained from rats at 2-h intervals for 24 h were stained with several mouse monoclonal antibodies directed against lymphocyte surface molecules and processed by flow cytometry. The number of B, total T, Tgammadelta, Th, and Ts/c cells followed a 24-h rhythm with a peak in the first half of the resting period. The expression of CD45, CD5, CD3, and CD4 followed a circadian rhythm. Their acrophases suggested temporal association between CD45 and CD5 at the end of the active phase and between CD4 and CD3 at the beginning of this phase. This temporal organization could have an important role for immune cell function.     

Diurnal rhythm of acid-base equilibrium and blood gas composition

Diurnal fluctuations of acid-alkaline balance and blood gas composition were studied in March on 20 healthy males aged 20-26. Using cosinor analysis, mesors, amplitudes and acrophases were revealed. Calculated acrophases (in h and min) are as follows: pH--16 h 05 min, standard hydrogen carbonate--18 h 45 min, actual hydrogen carbonate--22 h 55 min, buffer bases--19 h 03 min, pCO2--2 h 47 min, pO2--4 h 39 min, HbO2--8 h 07 min, hemoglobin--14 h 16 min. All the values studied during diurnal cycle correlated, forming certain circadian rhythms.     

In situ lymphophagocytosis by nonlymphoreticular neoplasms

Lymphophagocytosis by nonlymphoreticular neoplasms has been observed. Twenty cancer patients having either adenocarcinoma or epidermoid carcinoma were the subjects of our study. Malignant cells were found to phagocytize autologous lymphocytes, polymorphonuclear cells (PMNs) and red blood cells (RBCs). Papanicolaou smears from cancer patients revealed that 30% (6/20) of the patients had phagocytic malignant cells in situ, the mean phagocytosis for this group was 3.7%. Different cellular elements showed differences in their susceptibility towards phagocytic activity of tumor cells: 2.6% for lymphocytes, 0.7% for PMNs and 0.4% for RBCs. The patients having phagocytic malignant cells showed complete absence of monocytes in their peripheral blood. In contrast, other patients had peripheral blood monocyte percentages within the limits of control values (7.2). However, there was no correlation between development of phagocytic activity of malignant cells and age and sex of patients or type of tumor. This study further confirms that phagocytic activity of nonlymphoreticular neoplasms is a general phenomenon which can be directed against erythroid elements. In addition, we have demonstrated that these tumor cells also phagocytize autologous leukocytes.