Uric acid and renal function in multiple sclerosis.

OBJECTIVE: The purpose of this study was to examine the circadian distribution of creatinine and uric acid clearances in subjects with Multiple Sclerosis. MATERIALS AND METHODS: Eleven subjects with MS, 6 women (48+/-7y) and 5 men (58+/-5y) volunteered for this circadian study. Thirteen healthy females (39+/-11y) served as controls. Data of seven healthy male controls (64+/-8 y) were extracted from a similar circadian study conducted previously. Each MS patient, and each male control had blood samples drawn around the clock, at 3h intervals (8/24h), and each collected urines over 3h periods (8/24h). Each female control contributed only one blood sample and one complete 24h urine collection. Blood and urine samples were analyzed for a number of relevant analytes: ELAM, IL-6, NO, insulin, ACTH, aldosterone, cortisol, electrolytes, lymphocytes, monocytes including creatinine and uric acid clearances. Those were standardized to an average body surface area of 1.73 m2. RESULTS: The relevant analytes demonstrated increased synthesis of insulin, IL-6, ELAM, monocytes, and reduced concentrations of serum NO. The creatinine clearances were significantly lower in MS females than in female controls, 63+/-22 vs.108+/-18 ml/min. They were also lower than those of MS males and male controls, 107.8+/-17, 97.5+/-8.2 ml/min. Uric acid clearances in MS females were also lower 6.9+/-2.4 vs. 10.5+/-4.4 ml/min. The uric acid clearance in MS males was higher than in male controls, 7.0+/-4.5 vs. 4.0+/-1.0 ml/min. CONCLUSIONS: The alterations in selected relevant analytes and the reduced creatinine and uric acid clearances in females but not in males, suggest a renal dysfunction in MS females. These observations may contribute to understanding better the mechanism of renal dysfunction in female patients and perhaps this may be an additional factor contributing to greater frequency of MS in females than in male subjects.

Twenty-nine year study on circadian distribution of urinary zinc levels of same male subjects.

OBJECTIVES: To examine the circadian distribution and total 24h levels of urinary zinc (Zn) in same male subjects over an extended period of time in order to ascertain their relationship with aging. MATERIALS AND METHODS: Eight young army volunteers served as subjects over a period of 29 years: 1969, 1979, 1988, 1998. By 1979 three of them became latent diabetics. Complete physical examination, anthropometric measurements and same procedural protocol was followed in each study. Samples were collected over 3 hour periods for 24 hours in the middle of each month of May. Urine aliquots were analyzed for creatinine, using conventional laboratory procedure. Zn was analyzed using Atomic Absorption Spectrophotometry in 1969, and 1979 and by Inductively Coupled Plasma, in 1988 and 1998. RESULTS: Over the course of 29 years the circadian distribution of Zn was altered by decrease in amplitude in Zn levels, while the 24h concentrations of Zn decreased progressively with increasing age in healthy and diabetic subjects: Healthy; 966+/-130 microg at age of 29; 666+/-14 microg at 39; 511+/-80 microg at 48; and 555+/-71 microg at age of 58y; Diabetics exhibited similar trend; 1757+/-60 microg at age 28; 1253+/-40 microg at age 38, 1132+/-31 microg at 47, and 1025+/-11 microg at the age of 57. Anthropometric measurements in each study period revealed significant increases in diabetic subjects for body weight, body surface area, BMI and significant decrease in body heights of both groups. CONCLUSIONS: The daily excretion of urinary Zn over the 29 years period decreased by 42% in healthy and diabetic subjects. Although there appears to be a lack of a reliable index of intracellular Zn status to accurately monitor and control zinc deficiency in younger and older populations, the present data suggest that depletions of Zn are also evident in healthy aging subjects whose daily diet was not deficient in zinc.

Circadian distribution of serum cytokines in multiple sclerosis.

AIMS: The purpose of this study was to examine circadian distribution of selected cytokine levels (IL-2, IL-10, GM-CSF, TNF-alpha, and IFN-gamma) in serum of subjects with active Multiple Sclerosis (MS) and non-MS subjects. MATERIALS AND METHODS: Six females (36-56y) and five males (52-68y) with active MS volunteered and consented for the study conducted at Special Diagnostic Ward of this hospital. All subjects gave their medical history and were given complete physical examination. Low purine meals were served at 16:30, 07:30 and 13:00 h. Lights were "OFF' at 22:30 hr and "ON" at 06:30h. Blood collections were made at 3h intervals over a 24h period of time. Six healthy male subjects (53-76y) subjects' data were obtained from a study conducted 3 years previously using the same procedural protocol. Cytokine assays were assessed using commercial enzyme-linked immuno-absorbent procedure. Time series of average data and the range of change between the highest and lowest concentrations are presented for MS subjects along with data from non-MS subjects. RESULTS: IL-2, IL-10, and GM-CSF levels were significantly reduced in females with MS when compared with levels of healthy subjects while their IL-6 levels were increased. The IL-6, GM-CSF and TNF-alpha levels in males with MS were below detection limits. The TNF-alpha levels were essentially similar in MS females and healthy subjects. CONCLUSIONS: These preliminary studies, although with very small number of patients and healthy male controls appear to suggest that the circadian analysis of cytokines and other markers of immunity may have utility in understanding the pathogenesis of diseases like MS.

Relationships between 24h observations in intraocular pressure vs blood pressure, heart rate, nitric oxide and age in the medical chronobiology aging project.

OBJECTIVE: To evaluate associations between intraocular pressure (IOP) and blood pressure (BP), heart rate (HR), serum nitric oxide (NO), diurnal variations, diabetes and aging in data collected during 24h studies of men conducted over 34y. MATERIALS AND METHODS: As part of the Medical Chronobiology Aging Project, male Army veterans, ages 22 to 81y, without a history of eye disease, were studied around-the-clock in May 1969 (n = 13), 1979 (n = 11), 1988 (n = 11), 1993 (n = 11), 1998 (n =12) and 2003 (n = 10). Measurements of IOP (R & L eyes, supine position), BP and HR (sitting position), and collection of blood were obtained every 3h (8 readings/24h) from 19:00h to 16:00h the next day. Individual time series were analyzed for circadian characteristics by the least-squares fit of a 24& 12h cosine. After normalizing all data to percent of mean to reduce inter-subject variability in levels, grouped data were analyzed for time-effect by ANOVA and for circadian rhythm by multiple component (24h&12h) cosine fitting. Individual 24h averages were analyzed by simple and multiple regression for relationships between IOP and systemic variables, diabetic status and age. RESULTS: Over the 34y study span, 22 men provided sixty-three 24h profiles for IOP & HR, 61 for BP, and 21 for NO. Using all normalized data, a significant circadian rhythm was found for each variable at p <0.001. Circadian peaks (orthophases) are located in the late morning for IOP-R (10:20h) and IOP-L (10:52h), and in the evening for HR (18:52h), NO (20:00h), SBP (20:40h) and DBP (21:44h). An out-of-phase relationship of about 10h is noted on a group basis between IOP vs BP, HR and NO. The locations of individual circadian peaks for IOP-R were found around the clock, but with a significant predominance between 10:00 and 16:00h (day type), and 04:00-10:00h (morning type). In contrast, BP, HR and NO showed a significant clustering of evening type or night type peaks. The overall mean IOP for the right eye was slightly, but not significantly, higher than the left eye (17.60+/-0.21 vs 17.34+/-0.18 mmHg; p = 0.385), with a strong positive correlation between both eyes (R = 0.952, p <0.0001). IOP showed a significant positive correlation with SBP (R = 0.49, p <0.001), diabetic status (R = 0.47, p <0.001), age (R = 0.32, p = 0.011), and HR (R = 0.28, p = 0.031). A multiple regression using SBP, DBP, HR, age and diabetic status (5 men became diabetic over the 34y study span) as independent variables resulted in SBP being the strongest predictor of IOP (p = 0.0001), followed by DBP (p = 0.0103). After adjustment for BP, independent effects of age (p = 0.187), HR (p = 0.789) and diabetic status (p = 0.153) were eliminated from the prediction equation. CONCLUSIONS: The results of these studies reveal significant circadian variations in IOP, BP, HR and NO, with peak levels, on average, near noon for IOP and in the evening for BP, HR and NO. An increase in SBP was associated with an increase in IOP. While SBP and DBP are significant predictors of IOP levels, single measurements during regular clinic hours may not reveal the full functional relationship between the variables measured in our studies. Therefore, circadian information on total 24h patterns may contribute to the reliability of diagnosis and guide proper individualized timing of optimal patient management (e.g., for glaucoma, hypertension, diabetes, among other conditions).

Chronotherapy of ovarian cancer: effect on blood variables and serum cytokines. A case report.

A 7-year-old patient with Stage III-c ovarian cancer was subjected to 8 cycles, approximately four weeks apart, of chronobiologically-optimized treatments with combination of three anti-cancer agents: Four cycles at AM, Cytoxan and PM, cis-Platinum; four cycles at AM, Adriamycin and PM, cis-Platinum. A second look laporoscopy revealed clean intestines, no definite masses in the pelvis area although there was an apparent mass in the right upper pelvis and several slightly enlarged lymph nodes in the base of mesentery. Six cycles of Taxol were administered at about Noon. Seven months remission appeared evident as judged by no changes in monthly examinations, in blood work or in CA-125 marker levels which remained below 12 U/ml. During the eight month the CA-125 marker began to rise, 36 then to 52 U/ml. A second 6 cycle series of Taxol was initiated but the CA-125 marker continued to rise, 57, 65, 72, 86, and 87 U/ml level. The patient declined in spirit, in well-being and expired 2 weeks later, 31 months after the initial diagnosis of cancer. Blood hematology, chemistry, and cytokines variables were analyzed at about weekly intervals. Significant reductions in total WBC, neutrophiles and platelet levels were evident during the second week of all cycle treatments, while increases were noted in serum levels of IL-2, IL-6 and IL-10 following Cytoxan-cis-Platinum-Adriamycin, but not Taxol. After each infusion moderate and temporary increases in RBC levels were noted. The treatments impact on hematology, chemistry, cytokine variables and on the integrity of the patient, are presented and briefly discussed.

Circadian distribution of iron and ferritin in serum of healthy and type 2 diabetic males.

AIM: We examined the circulating levels of iron and ferritin in serum of seven healthy and three insulin non-dependent diabetic (Type 2) males in order to compare their circadian characteristics. METHODS: Blood samples were collected every 3h over a 24h period and were analyzed for serum iron and ferritin. RESULTS: The mean Fe level was significantly higher in healthy than in diabetic subjects: 80.0 +/- 3.3 vs. 63.0 +/- 3.7 microg/dL. The ferritin level was significantly lower in healthy than in diabetic men: 79.8 +/- 4.7 vs. 186.3 +/- 110.5 microg/L. A significant (p < 0.001) time-effect was found by ANOVA and circadian rhythm was detected at p < 0.001 in all data sets when a 24h cosine was fitted to the normalized data. Acrophases were located in mid to late morning for Fe (11:30, vs. 09:22h) and for ferritin (11:10 vs. 11:46h). DISCUSSION: We concluded that there is significant circadian variation in both serum Fe and ferritin, with predictable peaks in the mid to late morning.

Circadian variation in multiple sclerosis of oxidative stress marker of DNA damage. A potential cancer marker?

OBJECTIVE: To investigate circadian rhythm (CR) of urinary creatinine and 8-hydroxy-2-deoxyguanosine (8-OHdG) in patients with Multiple Sclerosis (MS) and to present concentrations of this DNA damage marker, 5 years prior to mastectomy, in one MS study subject, and 2 years prior to biopsy confirmed a carcinoma (CA) of the prostate in one non-MS subject. MATERIALS AND METHODS: Eleven subjects with MS (6 women 36-52 years of age and 5 men 51-68 years) volunteered for this study, carried out at Edward Hines Jr., Medical Center. Subjects were offered a general hospital diet (2400 cal in total/24h) at 16:30h, 07:30h and 13:00h. The dark (sleep) phase of the light-dark cycle extended from 22:30h to 06:30h with brief awakening for sampling at 01:00h, and 04:00h. Urine samples were collected for consecutive 3h spans beginning at 16:00-19:00h and were analyzed for creatinine and 8-OHdG. Twelve men (including 3 with type 2 diabetes) provided 21 profiles according to the same protocol used for comparison. In addition, 10 healthy women provided 24h urine samples. Statistical analysis of data was performed using the Single-Cosinor and Population-Mean Cosinor. RESULTS: A CR was detected for creatinine in healthy men (p < 0.001) but not for MS patients. Urinary creatinine concentrations were lower in MS women than in healthy women (p = 0.015) and were lower in MS women than in men healthy or with MS (p < 0.001): Women; MS 655 +/- 76; H 1381 +/- 316; Men, MS 1830 +/- 285; H 1532 +/- 265 mg/24h vol. A CR was evident in 8-OHdG in MS (p = 0.007) and in non-MS subjects (p < 0.001) with highest values occurring at about 16:45h. The average concentrations of 8-OHdG in MS patients were similar to those in healthy subjects: Women, MS 589 +/- 125; H 794 +/- 318; Men, MS 504 +/- 156; H 591 +/- 134 picomoles/kg bw/24h vol. The 8-OHdG concentrations of a MS patient, later diagnosed with breast cancer, were found to exceed the upper 95% prediction limit in health. An increased 8-OHdG level was also noted in a non-MS subject who 2 years later received a biopsy-confirmed diagnosis of prostate CA. CONCLUSIONS: Despite the small number of subjects in this study, a statistically significant CR was documented for 8-OHdG in urine of subjects with MS. Interestingly, the increased concentrations of DNA damage marker, the 8-OHdG, 5 years prior to mastectomy and the 2 years prior to affirmative diagnosis of prostate CA, could be the most significant clinical observations of this study. Follow-up studies of a larger population of subjects would, thus, be required to ascertain the predictive validity of such challenging observation.

Circadian distribution of hematology variables in subjects with multiple sclerosis.

Hematology variables were measured in blood samples obtained every 3h (8/24h) from 10 multiple sclerosis (MS) patients and 34 healthy subjects and analyzed for circadian characteristics using the population multiple-components method. Red blood cell (RBC) and hemoglobin levels as well as hematocrits exhibited circadian rhythms with minimal amplitudes in healthy individuals and insignificant variability in the smaller group of MS patients. In contrast the total white blood cell (WBC) and platelet counts for MS patients and healthy individuals both showed significant circadian characteristics while the mean 24h WBC and platelet levels did not significantly differ between the two groups. When the different WBC subsets were examined independently, statistically significant circadian rhythms were seen for lymphocytes and eosinophils for both MS patients and healthy individuals and for neutrophils only in the latter. Moreover, the 24h mean levels of lymphocytes, basophils, and eosinophils were significantly higher for the healthy controls while those of monocytes were higher for the MS patients. However, of all the variables tested with significant circadian rhythms in both groups of individuals, only those of lymphocyte numbers exhibited different patterns with somewhat higher amplitude in healthy individuals and a peak level occurring over an hour after that of MS patients. These changes may be the reflection of a disturbance in the regulation of patterns of lymphocyte activity and migration in MS patients. In addition, the elevation in circulating monocytes in MS patients is consistent with the inflammatory nature of the disease.

Weekly and yearly rhythms in plasma fibrinogen in hospitalized male military veterans.

The variation in plasma fibrinogen level demonstrating prominent circaseptan and circannual cycles is clinically relevant. There is a correlation between increasing level of fibrinogen and other hemostatic factors and risk of myocardial infarction and sudden death. The circaseptan and circannual cycles in fibrinogen concentration described in this study may help to explain further the variation in frequency of coronary events. Furthermore, the recent demonstration of a circadian pattern in the efficacy of tissue plasminogen activator, with peak efficacy occurring at 2000 hours--10 hours after the peak incidence of myocardial infarction--implies that further patterns to coronary artery syndromes may be predicted and the treatment efficacy may rely on demonstrated circaseptan and circannual cycles of these events.

Circadian rhythm of serum total homocysteine in men.

Serum homocysteine levels were examined in a 24-hour study of 7 healthy and 5 diabetic men, revealing a statistically significant circadian rhythm (p = 0.030), normal concentrations of 11.83 +/- 1.2 vs 12.99 +/- 1.2 micromol/L, with peak values occurring during the evening (10:37 P.M.) and lowest levels occurring during the morning. These findings imply that increased atherosclerotic risk in insulin-resistant diabetics during morning hours does not appear to be explained by differences in homocysteine levels in the normal population.

Circadian relationships between circulating atrial natriuretic peptides and serum calcium and phosphate in healthy humans.

Long-acting natriuretic peptide (LANP), vessel dilator (VSDL), and atrial natriuretic factor (ANF) consisting of amino acids (aa) 1 to 30, 31 to 67, and 99 to 126, respectively, of the 126-aa ANF prohormone circulate in humans. Among the biologic properties of these peptides is the ability of ANF to decrease intracellular calcium concentrations. To determine if atrial natriuretic peptides are directly related to serum calcium and/or phosphate in healthy normocalcemic humans, we examined 21 24-hour profiles of VSDL, LANP, ANF, and serum calcium and phosphate in 14 healthy humans. VSDL, LANP, and ANF each had significant (P < .001) circadian rhythms, with peak concentrations late during sleep (at 4:00 AM) being nearly twice the concentrations in the afternoon and evening. Serum calcium and phosphate also had significant circadian rhythms (P < .001) with troughs nearly opposite to those of the atrial natriuretic peptides, suggesting that atrial peptides may be important in the modulation of the circadian rhythms of calcium and phosphate. The nearly identical circadian rhythms of the atrial natriuretic peptides and of parathyroid hormone (PTH) reported by others, along with evidence that PTH may increase atrial peptide release, suggest that some of the effects attributed to PTH may be mediated by atrial natriuretic peptides.

Temporal (circadian) and functional relationship between prostate-specific antigen and testosterone in healthy men.

OBJECTIVES: To study the circadian relationship between serum prostate-specific antigen (PSA) and total testosterone in men without clinically evident prostate disease. METHODS: Blood samples were collected every 3 hours for 24 hours (eight per subject) from 11 clinically healthy men, ages 46 to 72 years. PSA was also monitored once a week for 6 weeks in 16 additional healthy men. PSA, testosterone, and age were correlated by linear regression, and 3-hourly PSA and testosterone values normalized to percent of individual mean were analyzed for circadian rhythm by the least squares fit of a 24-hour cosine. RESULTS: Mean PSA correlated positively (P < 0.001) and testosterone correlated negatively (P = 0.014) with age and inversely with each other (P < 0.001). The mean circadian range of change (ROC) from lowest to highest values for PSA was 0.37 +/- 0.07 ng/mL (28 +/- 9%), and for testosterone it was 202 +/- 23 ng/dL (53 +/- 7%). The mean ROC over 6 weeks was 0.32 +/- 0.04 ng/mL. A significant circadian rhythm was found for PSA (P = 0.011, amplitude = 5.4 +/- 1.8%, acrophase = 5:02 AM; 95% limits, 2:40 to 7:24 PM) and testosterone (P < 0.001, amplitude = 9.4 +/- 1.8%, acrophase = 8:38 AM; 95% limits, 7:12 to 10:04 AM). CONCLUSIONS: The temporal relationship between circadian rhythms in PSA and testosterone suggests different physiologic states over the 24 hours, which may be of chronopharmacologic interest with regard to dosing time of drugs or hormonal treatments intended to affect prostate growth and function. Within-day variation in PSA is of little diagnostic significance and does not prevent accurate clinical classification when a single specimen is used.

Reference values for circadian rhythms of 98 variables in clinically healthy men in the fifth decade of life.

Nine clinically healthy men, 41-47 yr of age, served as subjects in a 24-hr study conducted at the Edward Hines Jr Veterans Administration Hospital in the Chicago area in May 1988. Physiologic measurements, and blood and urine samples were collected at 3-hr intervals over a single 24-hr period beginning at 1900. The number of variables measured or calculated (total = 98) included: 6 vital signs (oral temperature, pulse, blood- and intraocular pressures); 16 in whole blood (counts and differentials); 50 in serum (SMAC-24, lipids, hormones, electrophoresis of LDH and proteins); and 26 in urine (solids, proteins, creatinine, catecholamines, melatonin, cortisol, electrolytes and metals). Data were analyzed for time effect by analysis of variance (ANOVA) and for circadian rhythm by single cosinor. Individual rhythm characteristics for each variable were summarized for the group by population mean cosinor. The vast majority of variables revealed statistically significant within-day changes in values as validated by one-way ANOVA. All vital signs (except for intraocular pressures) and all serum hormones displayed a prominent circadian rhythm for the group, as did most variables in whole blood, while only about half of the variables in urine demonstrated a significant group rhythm. The results obtained are meant to: (a) document the circadian time structure; and (b) serve as reference values for circadian rhythm characteristics (range of change, mesor, amplitude and acrophase) for a defined group of individuals: clinically-healthy adult men in the prime of life.

Circadian rhythmometry of serum interleukin-2, interleukin-10, tumor necrosis factor-alpha, and granulocyte-macrophage colony-stimulating factor in men.

Serum levels of four cytokines [tumor necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2), granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukin-10 (IL-10)] were measured in nine diurnally active healthy adult male subjects at 3-h intervals during a 24-h period. Statistical evaluation by analysis of variance and/or the least- squares fit of a cosine model revealed significant 24-h rhythms for each cytokine. Although the amount of IL-2 in the serum was low, the levels fluctuated to form a single peak at approximately noon. In contrast, the other three cytokines exhibited a biphasic temporal pattern. In subjects with detectable TNF-alpha levels, the first peak occurred at 07:30 and the second at 13:30. IL-10 levels also exhibited a biphasic pattern, with one peak at 07:30 and the second 12 h later at 19:30. GM-CSF levels were last to rise, first peaking at approximately 13:30 and then again at 19:30. These results suggest temporal patterns that are unique for each cytokine, generally with daytime highs and nighttime lows.

The circadian rhythm of the N-terminus and C-terminus of the atrial natriuretic factor prohormone.

Circadian variation in the circulating concentrations of the N-terminal and C-terminal portions of the atrial natriuretic factor prohormone (pro ANF) was evaluated in 8 men, ages 41-47, who have been followed for 19 years with respect to circadian variation in physiological variables including blood pressure and clinical chemistries. The N-terminus of the ANF prohormone contains two peptides consisting of amino acids 1-30 and 31-67 while the C-terminus contains 1 peptide (amino acids 99-126) of this 126 amino acid prohormone which lower blood pressure and have natriuretic properties. To determine if either the N-terminus and/or the C-terminus of the prohormone have a circadian variation in their circulating plasma concentrations these 8 men had blood samples obtained for radiommunoassay every 3 hr during a 24-hr period. Three radiommunoassays which immunologically recognize (1) the whole N-terminus (i.e. amino acids 1-98), (2) the midportion of the N-terminus (amino acids 31-67) and (3) the C-terminus (amino acids 99-126) of the ANF prohormone were utilized. The whole N-terminus, the midportion of the N-terminus which circulates after being proteolytically cleaved from the rest of the N-terminus, and the C-terminus each had a peak circulating concentration between 0400 and 0700 which were significantly (P less than 0.001) higher than their concentrations at any other time throughout the 24-hr period.(ABSTRACT TRUNCATED AT 250 WORDS)

Ten-year-replicated circadian profiles for 36 physiological, serological and urinary variables in healthy men.

At 3-hr intervals over a 24-hr span, 36 systemic, serologic and urinary variables were examined in 7 men in their mid 20's in the Spring of 1969, and again in the same 7 men in the Spring of 1979 under a similar chronobiologic protocol, using the same chemical and numerical analytical procedures. The variables examined for rhythms by cosinor were: vital signs--blood pressure (systolic, diastolic, pulse pressure and mean arterial pressure), heart rate, intraocular pressure (left and right), oral temperature; serum components--albumin, albumin/globulin ratio, total bilirubin, calcium, carbon dioxide, chlorides, bilirubin, cholesterol, globulin, glucose, potassium, sodium, sodium/potassium ratio, transaminase, triglycerides, total protein, urea nitrogen; and urine components--calcium, calcium/magnesium ratio, creatinine, magnesium, pH, potassium, sodium, sodium/potassium ratio, urea clearance, urea nitrogen, volume and zinc. Although all subjects appeared clinically healthy in 1969 and in 1979, certain inter-study differences were observed in a number of rhythm parameters of different variables. Statistically significant increases in mesor for the group as a whole were observed for serum Ca, cholesterol, Cl, CO2, K, Na, and while statistically significant mesor decreases for a group as a whole were noted in serum glucose and transaminase. Statistically significant increases in amplitude for the group as a whole were observed in serum chloride and urinary Na/K ratio, while statistically significant decreases were observed in amplitude for blood pressure, heart rate, serum albumin, A/G ratio, globulin, glucose, protein, sodium and transaminase.(ABSTRACT TRUNCATED AT 250 WORDS)

Circadian characteristics of dialyzable and non-dialyzable human urinary electrolytes, trace elements and total solids.

Seven clinically-healthy men ranging in age from 21 to 25 years participated in this study. Urine samples were collected at 3 hr intervals over a single 24 hr span. Urines were pooled by using 20% of the total volume collected from each subject over a 3 hr collection span. The resulting 8 pools were analyzed for pH, specific gravity, osmolality, urea N, creatine, uric acid, glucose, phosphorus, chlorides, sodium, potassium, calcium, magnesium, silicon, aluminum, zinc and total solids. Each of the 8 pools was serially dialyzed at pH 7.35 against ammonium-barbituric acid buffer. The non-dialyzable portions were then re-analyzed for the remaining solids, sodium, potassium, calcium, magnesium, silicon, aluminum and zinc. Aliquots of the non-dialyzable fraction were examined by high performance liquid chromatography. Up to twelve discernable fractions were observed in each 3 hr urine by monitoring ultraviolet light absorbance at 280 nm wavelength. Range of change throughout the 24 hr (lowest to highest value) for most variables was 100% or more. In the eight 3 hr pooled urine samples, statistically-significant circadian variation could be described for volume, pH, osmolality, urea nitrogen, creatinine, uric acid, glucose, phosphorus, chlorides, for five of eight non-dialyzed (total) components (Na, K, Ca, Si and solids) and for five of twelve non-dialyzable solid fractions, as well as for total non-dialyzable solids. Single cosinor analysis resulted in description of a significant circadian rhythm in osmolality, urea nitrogen, creatinine, glucose, phosphorus, chlorides, total Na, K, Si and solids; non-dialyzable Si and solids; dialyzable Na, K, Si and solids; and for total solids, as well as their fractions at 23.4 and 25.9 min. These observations are furnished in order to further document the extreme circadian rhythmicity in all aspects of kidney function and as reference for future work which uses any of the investigated urinary endpoints whose circadian time structure is herein described.

Circadian distribution of proteins in urine from healthy young men.

Urine samples were collected at 3-hr intervals over a single 24-hr period from each of seven clinically healthy men who ranged in age from 21-25 years. Urines at each collection time were subsequently pooled using 20% of each volume and serially dialyzed against ammonium-barbituric acid buffer (pH 7.35 +/- 0.02), using a cellulose membrane permeable to compounds of less than 12,000-14,000 molecular weight (mw). When the dialyzed portions were then analyzed for total proteins, the sum of proteins in eight pools amounted to 74 mg. A 1 ml aliquot of each pool, representing approximately 50 micrograms of proteins, was concentrated and reconstituted. Approximately 20 micrograms of reconstituted proteins were then subjected to polyacrylamide gel electrophoresis. The stained gel was then scanned by laser densitometry and planimetry. Each aliquot revealed eight segments as identified by Coomassie and silver staining. Their molecular weights, estimated by extrapolation from concurrently run protein standards, and their total protein amounts were: 116,000 mw (9.44 mg), 91,000 mw (3.3 mg), 68,000 mw (11.58 mg), 53,000 mw (2.58 mg), 43,000 mw (9.12 mg), 32,000 mw (7.13 mg), 24,000 mw (4.52 mg) and 20,000 mw (5.27 mg). A statistically significant rhythm (P = 0.022 from ANOVA and 0.011 from Single Cosinor) was found for the excretion of total proteins, with an acrophase in the afternoon (1537) for these diurnally-active subjects.

Heparin as a therapy for atherosclerosis: preliminary observations on the intrapulmonary administration of low-dose heparin in the morning versus evening gauged by its effect on blood variables.

Reports on clinical trials with subcutaneous and intrapulmonary administration of low-dose heparin suggest that it may be an attractive therapeutic modality for the treatment of coronary artery disease because of unprecedented reduction in mortality of treated subjects. As a preliminary to a clinical trial with low-dose intrapulmonary heparin, a pilot study was conducted on three subjects. It compares overall circadian responses of 37 blood variables following intrapulmonary administration of heparin (10,500-18,800 U) in the morning (0800 h) and in the evening (2000 h). After each of these times, blood samples, mostly at 3 h intervals for the ensuing 27 h, were analyzed for heparin, APTT, TT, functional fibrinogen, CBC, enzymes, lipids, electrolytes, and hormones. Each time series was analyzed for circadian rhythm by the least-squares fit of a 24 h cosine and circadian mesors were compared by the Bingham test of rhythm parameters. Following heparin in the evening, but not in the morning, a statistically significant increase in circulating heparin levels, as well as directional increases in APTT and TT and decreases in fibrinogen, were observed in all three subjects. Same direction changes in several other variables were also observed. It is concluded that inhalation of heparin in low-dose levels results in variable circadian effects on blood parameters measured, ranging from no changes in their levels to minimal within normal range changes, and that these effects are dependent upon the timing of dose administration. It is suggested that the timed self-administration of low-dose heparin by inhalation be seriously considered for long-term clinical trials in the treatment and prevention of atherosclerosis.

Temporal (circadian) and functional relationship between atrial natriuretic peptides and blood pressure.

Long-acting natriuretic peptide, vessel dilator, and atrial natriuretic factor consisting of amino acids (a.a.) 1 to 30, 31 to 67, and 99 to 126 of the 126-a.a. atrial natriuretic factor (ANF) prohormone, respectively, circulate in humans and have potent vasodilatory properties. To determine if these atrial natriuretic peptides are directly related to blood pressure in clinically healthy normotensive humans, we obtained 24-h profiles of vessel dilator, long-acting natriuretic peptide, ANF, and blood pressure in 10 men in 1988 and 11 men in 1993 (seven men were studied twice) to compare circulating concentrations of atrial natriuretic peptides with naturally occurring changes in blood pressure. Overall, vessel dilator, long-acting natriuretic peptide, and ANF each had significant (p<0.001) circadian rhythms, with peak concentrations late during sleep (at 04:00 h) being nearly twice their concentrations in the afternoon and evening. This high-amplitude circadian change allowed for the refinement of normal limits for ANF peptides by computing 3-hourly tolerance intervals (chronodesms) against which to compare time-specified single samples for normality. Systolic, diastolic, and mean arterial blood pressure also had significant circadian rhythms (p<0.001) with peaks and troughs that were exactly opposite those of the ANF peptides. In addition to this inverse temporal relationship, there was a significant inverse correlation between absolute values for blood pressure and each ANF peptide (p<0.001), implying a functional relationship. These data suggest that in addition to other well-established neurochemical factors, the ANF peptides (vessel dilator, long-acting natriuretic peptide, and ANF) are important for the maintenance of blood pressure and modulation of its circadian rhythm.