Heterogeneous activity of rodent and lagomorph parotid gland extracts on the hemocoagulation process

Anticoagulant properties of parotid glands belonging to four species of mammals (rat, mouse, rabbit and hare) were investigated on the hemostatic system of human being. Heterogeneous effects of the glycoconjugates extractable from different species were demonstrated by means of thromboelastography and hemocoagulation screening tests. In fact, glycoconjugates isolated from the rodent (rat and mouse) parotid glands changed all the thromboelastographic parameters and the hemocoagulation tests (Thrombin Time, Prothrombin Time, Partial Thromboplastin Time). Glycoconjugates extracted from the rabbit parotid gland strongly affected the thromboelastogram parameters in addition to the Partial Thromboplastin Time. Finally, glycoderivatives obtained from the hare parotid gland only influenced the Partial Thromboplastin Time.     

Lack of hemostatic effects of adult and suckling cat salivary gland heteropolysaccharides on blood coagulation

Like other mammalian salivary glands, the cat submandibular and parotid glands belonging to adult and growing subjects contain heteropolysaccharides with very heterogeneous composition. Such glycoconjugates were this time tested in humans at doses used previously showing anticoagulant properties in rodents and lagomorphs. But surprisingly, no anticoagulant effects could be detected consistently. In fact, neither thromboelastography, nor hemocoagulation screening tests were affected in a statistically significant manner.     

Nonlinear effects in kinetics of blood coagulation

A linear mathematical model of the kinetics of humoral system of hemocoagulation is presented in the works by Levin (1966), Moro a. Brakhucha-Reyd (1969), Martoran a. Moro (1974). Present paper considers a nonlinear mathematical model of the intrinsic path of hemocoagulation which takes into account the effect of positive feed back which is related to the action of factors Va and VIIIa as co-factors. It is found that the intrinsic path of hemocoagulation normally functions as an amplifier cascade, if the wall damage is above some threshold value. When the damage is below the threshold value the intrinsic path of hemocoagulation does not function.     

Screening study of the effects of the hypothalamic-pituitary-thyroid axis on hemostasis in rats

The hormonal regulation of hemostasis has had little attention in research, and the existing literature data are relatively contradictory. The possible effects of the hormones of the hypothalamic-pituitary-thyroid axis on hemocoagulation and the fibrinolytic system are studied here. The study was conducted on 80 white male rats of the Wistar breed. The necessary blood quantity was obtained by cardiac puncture realized under ether narcosis. The basic parameters of the hemocoagulation and fibrinolytic activity of the plasma were determined by Diagnostica Stago tests (France), using an automatic coagulometer (Italy). The hormones employed in the study: Thyreotropin releasing hormone (0.06 mg/kg bw), Thyroid stimulating hormone (1 MU/kg bw), Triiodothyronine (0.08 mg/kg bw), and Thyroxin (0.08 mg/kg bw) applied s.c. for three consecutive days, extended the activated partial thromboplastine time (p less than 0.001), proto-thromboplastine time (p less than 0.001), thrombin time (p less than 0.001), reptilase time (p less than 0.001), and shortened the euglobin clot lysis time of (p less than 0.001). These data indicate that each of the hormones used causes significant changes in hemostasis by suppressing the coagulability by the intrinsic and extrinsic system pathways, and transformation of fibrinogen into fibrin. The shortened euglobim clot lysis time may be recognized as a manifestation of increased levels of plasma plasminogen activators. The results obtained show that hypothalamic-pituitary-thyroid hormones are significant regulators of hemostasis, since they cause an expressed hypocoagulation and increase plasma fibrinolytic activity.     

Changes in the hemostatic function of muscle tissue in phylogenesis

Studies have been made on coagulating and fibrinolytic activity of muscle tissue from various animals (earthworm, clam, car, frog, pigeon, rat). It was shown that extracts from muscles of these animals contain activators and inhibitors of hemocoagulation and fibrinolysis, exhibiting also antiheparin activity. It is concluded that progressive development of hemostatic function of muscle tissue involves the decrease in anticoagulating activity and the increase of thromboplastic activity.     

The effect of daily repeated sedation using ketamine or ketamine combined with medetomidine on physiology and anesthetic characteristics in Rhesus Macaques

Background  Non-human primates are frequently sedated to permit handling that can alter physiological values. The purpose of this study was to identify the effects of daily serial sedation using ketamine (K) or ketamine combined with medetomidine (KM). We hypothesized KM would reduce observed effects of repeated sedation.
Methods  Eight rhesus macaques were anesthetized for three consecutive days. Physiological data were recorded daily at 5-minute intervals. Time intervals from injection to ataxia, recumbency, first movement and recovery were recorded. Depth of anesthesia was evaluated.
Results  Data showed an 11.7% increased heart rate at 5 minutes between the first and third day of injection with K and 17.9% with KM. Time from injection to ataxia increased 13.7% with K and 14.3% with KM. Time to recumbency increased 34.7% with K and 37.1% with KM.
Conclusion  These findings demonstrate repeated anesthesia with ketamine can initiate changes suggesting a tolerance effect.     

Factors affecting work ability in day and shift-working nurses

Satisfactory work ability is sustained and promoted by good physical and mental health and by favorable working conditions. This study examined whether favorable and rewarding work-related factors increased the work ability among European nurses. The study sample was drawn from the Nurses' Early Exit Study and consisted of 7,516 nursing staff from seven European countries working in state-owned and private hospitals. In all, 10.8% were day, 4.2% were permanent night, 20.9% were shift without night shift, and 64.1% were shift workers with night shifts. Participants were administered a composite questionnaire at baseline (Time 0) and 1 yr later (Time 1). The Work Ability Index (WAI) at Time 1 was used as the outcome measure, while work schedule, sleep, rewards (esteem and career), satisfaction with pay, work involvement and motivation, and satisfaction with working hours at Time 0 were included as potential determinants of work ability. Univariate and multivariate analyses were conducted after adjusting for a number of confounders (i.e., country, age, sex, type of employment, family status, and other job opportunities in the same area). Work schedule was not related to Time 1 changes in WAI. Higher sleep quality and quantity and more favorable psychosocial factors significantly increased work ability levels. Higher sleep quality and quantity did not mediate the effect of work schedule on work ability. No relevant interaction effects on work ability were observed between work schedule and the other factors considered at Time 0. As a whole, sleep and satisfaction with working time were gradually reduced from day work to permanent night work. However, scores on work involvement, motivation, and satisfaction with pay and rewards were the highest in permanent night workers and the lowest in rotating shift workers that included night shifts.     

Factors Affecting Work Ability in Day and Shift‐Working Nurses

Satisfactory work ability is sustained and promoted by good physical and mental health and by favorable working conditions. This study examined whether favorable and rewarding work‐related factors increased the work ability among European nurses. The study sample was drawn from the Nurses' Early Exit Study and consisted of 7,516 nursing staff from seven European countries working in state‐owned and private hospitals. In all, 10.8% were day, 4.2% were permanent night, 20.9% were shift without night shift, and 64.1% were shift workers with night shifts. Participants were administered a composite questionnaire at baseline (Time 0) and 1 yr later (Time 1). The Work Ability Index (WAI) at Time 1 was used as the outcome measure, while work schedule, sleep, rewards (esteem and career), satisfaction with pay, work involvement and motivation, and satisfaction with working hours at Time 0 were included as potential determinants of work ability. Univariate and multivariate analyses were conducted after adjusting for a number of confounders (i.e., country, age, sex, type of employment, family status, and other job opportunities in the same area). Work schedule was not related to Time 1 changes in WAI. Higher sleep quality and quantity and more favorable psychosocial factors significantly increased work ability levels. Higher sleep quality and quantity did not mediate the effect of work schedule on work ability. No relevant interaction effects on work ability were observed between work schedule and the other factors considered at Time 0. As a whole, sleep and satisfaction with working time were gradually reduced from day work to permanent night work. However, scores on work involvement, motivation, and satisfaction with pay and rewards were the highest in permanent night workers and the lowest in rotating shift workers that included night shifts.     

Effect of time-of-day-specific strength training on serum hormone concentrations and isometric strength in men

A time-of-day influence on the neuromuscular response to strength training has been previously reported. However, no scientific study has examined the influence of the time of day when strength training is performed on hormonal adaptations. Therefore, the primary purpose of this study was to examine the effects of time-of-day-specific strength training on resting serum concentrations and diurnal patterns of testosterone (T) and cortisol (CORT) as well as maximum isometric strength of knee extensors. Thirty eight diurnally active healthy, previously untrained men (age 20-45 yrs) underwent a ten-week preparatory strength training period when sessions were conducted between 17:00-19:00 h. Thereafter, these subjects were randomized into either a morning (n=20, training times 07:00-09:00 h) or afternoon (n=18, 7:00-19:00 h) training group for another ten-week period of time-of-day-specific training (TST). Isometric unilateral knee extension peak torque (MVC) was measured at 07:00, 12:00, 17:00, and 20:30 h over two consecutive days (Day 1 & Day 2) before and after TST. Blood samples were obtained before each clock-time measurement to assess resting serum T and CORT concentrations. A matched control group (n=11) did not train but participated in the tests. Serum T and CORT concentrations significantly declined from 07:00 to 20:30 h on all test days (Time effect, p<.001). Serum CORT at 07:00 h was significantly higher on Day 1 than Day 2 in the control and afternoon group, both in Pre and Post conditions (Day x Time interaction, p<.01). In the morning group, a similar day-to-day difference was present in the Pre but not Post conditions (Time x Group interaction, p<.05). MVC significantly increased after TST in both the morning and afternoon groups (Pre to Post effect, p<.001). In both groups, a typical diurnal variation in MVC (Time effect, p<.001) was found, especially on Day 2 in the Pre condition, and this feature persisted from Pre to Post in the afternoon group. In the morning group, however, diurnal variation was reduced after TST on both Day 1 and Day 2 (Pre to PostxDay x TimexGroup interaction, p<.05). In conclusion, 10 weeks of morning time-of-day-specific strength training resulted in reduced morning resting CORT concentrations, presumably as a result of decreased masking effects of anticipatory psychological stress prior to the morning testing. The typical diurnal pattern of maximum isometric strength was blunted by the TST period in the morning but not the afternoon group. However, the TST period had no significant effect on the resting total T concentration and its diurnal pattern and on the absolute increase in maximum strength.     

Influence of Aspirin Usage on Blood Pressure: Dose and Administration-Time Dependencies

This study investigates the possible effects of acetylsalicylic acid (ASA; aspirin) on systolic (S) and diastolic (D) blood pressure (BP) in healthy and mildly hypertensive subjects receiving ASA at different times according to their rest-activity cycle. A double-blind, randomized, controlled trial was conducted in 73 healthy young adult volunteers and 18 previously untreated subjects with mild hypertension. The BP of each subject was automatically monitored every 30 minutes for 48h before the trial and at the end of a one-week course of placebo and a one-week course of ASA. Healthy volunteers were randomly assigned to one of six groups, defined according to the dose of ASA (either 500 mg/day, the usual commercial dose; or 100 mg/day) and timing of ASA and placebo (within 2h after awakening, Time 1; 7h to 9h after awakening, Time 2; or within 2h of bedtime, Time 3). Subjects with mild hypertension the low dose of 100 mg/day ASA, as well as one week of placebo, and were randomly assigned to one of the same three groups defined above according to the time of treatment. A small (?2 mmHg in the 24h mean of SBP), but statistically significant, BP reduction was found when 500 mg/day ASA was given to healthy volunteers at Time 2. With 100 mg/day, the effect of ASA in healthy subjects was comparable to the BP reduction found with the higher dose for Time 2; there was again no effect on BP at Time 1, but we found a statistically significant effect at Time 3 (2.3 mmHg reduction in the 24h mean of SBP), larger than for Time 2. For hypertensive patients, the BP reduction was again statistically significant for Time 2 and, to a greater extent, for Time 3 (?4.5 mmHg for both SBP and DBP); all patients in these two groups showed a BP reduction after one week of ASA. The effect was about three times as large as the BP reduction obtained in healthy subjects treated with 100 mg/day ASA. Results indicate a statistically significant time- and dose-dependent effect of ASA on BP. In any meta-analysis of ASA effects, inquiries about the time when subjects took the drug are indicated and may account for discrepancies in the literature. Moreover, the influence of ASA on BP demonstrated here indicates the need to identify and control for ASA effects in patients using ASA before or during their participation in antihypertension medication trials. (Chronobiology International, 14(6), 619–637, 1997)     

Prothrombin Time and Activated Partial Thromboplastin Time Testing: A Comparative Effectiveness Study in a Million-Patient Sample

Background

A substantial fraction of all American healthcare expenditures are potentially wasted, and practices that are not evidence-based could contribute to such waste. We sought to characterize whether Prothrombin Time (PT) and activated Partial Thromboplastin Time (aPTT) tests of preoperative patients are used in a way unsupported by evidence and potentially wasteful.

Methods and Findings

We evaluated prospectively-collected patient data from 19 major teaching hospitals and 8 hospital-affiliated surgical centers in 7 states (Delaware, Florida, Maryland, Massachusetts, New Jersey, New York, Pennsylvania) and the District of Columbia. A total of 1,053,472 consecutive patients represented every patient admitted for elective surgery from 2009 to 2012 at all 27 settings. A subset of 682,049 patients (64.7%) had one or both tests done and history and physical (H&P) records available for analysis. Unnecessary tests for bleeding risk were defined as: PT tests done on patients with no history of abnormal bleeding, warfarin therapy, vitamin K-dependent clotting factor deficiency, or liver disease; or aPTT tests done on patients with no history of heparin treatment, hemophilia, lupus anticoagulant antibodies, or von Willebrand disease. We assessed the proportion of patients who received PT or aPTT tests who lacked evidence-based reasons for testing.

Conclusions

This study sought to bring the availability of big data together with applied comparative effectiveness research. Among preoperative patients, 26.2% received PT tests, and 94.3% of tests were unnecessary, given the absence of findings on H&P. Similarly, 23.3% of preoperative patients received aPTT tests, of which 99.9% were unnecessary. Among patients with no H&P findings suggestive of bleeding risk, 6.6% of PT tests and 7.1% of aPTT tests were either a false positive or a true positive (i.e. indicative of a previously-undiagnosed potential bleeding risk). Both PT and aPTT, designed as diagnostic tests, are apparently used as screening tests. Use of unnecessary screening tests raises concerns for the costs of such testing and the consequences of false positive results.     

Effects of exposure to electromagnetic fields emitted by GSM 900 and WCDMA mobile phones on cognitive function in young male subjects

Results of studies on the possible effects of electromagnetic fields emitted by mobile phones on cognitive functions are contradictory, therefore, possible effects of long‐term (7 h 15 min) electromagnetic field (EMF) exposure to handset‐like signals of Global System for Mobile Communications (GSM) 900 and Wideband Code‐Division Multiple Access (WCDMA) on attention and working memory were studied. The sample comprised 30 healthy male subjects (mean ± SD: 25.3 ± 2.6 years), who were tested on nine study days in which they were exposed to three exposure conditions (sham, GSM 900 and WCDMA) in a randomly assigned and balanced order. All tests were presented twice (morning and afternoon) on each study day within a fixed timeframe. Univariate comparisons revealed significant changes when subjects were exposed to GSM 900 compared to sham, only in the vigilance test. In the WCDMA exposure condition, one parameter in the vigilance and one in the test on divided attention were altered compared to sham. Performance in the selective attention test and the n‐back task was not affected by GSM 900 or WCDMA exposure. Time‐of‐day effects were evident for the tests on divided and selective attention, as well as for working memory. After correction for multiple testing, only time‐of‐day effects remained significant in two tests, resulting in faster reactions in the afternoon trials. The results of the present study do not provide any evidence of an EMF effect on human cognition, but they underline the necessity to control for time of day. Bioelectromagnetics 32:179–190, 2011. © 2010 Wiley‐Liss, Inc.     

尖吻蝮(Agkistrodon acutus)蛇毒凝血酶样成分的研究 Ⅱ.酶学与血液学活性的研究

对四个凝血酶样成分(TLP)的酶学性质的比较研究表明,它们都具有凝结(血)活性和精氨酸酯酶活性。其凝结活力TLP_4>TLP_3>TLP_1>TLP_2,Ca~(++)有激活作用,但不被肝素、EDTA所抑制;精氨酸酯酶活力以TLP_1、TLP_2较高,Ca~(++)、EDTA无明显的激活或抑制作用;TLP_1对热比较稳定,TLP_4对于酸碱变化比较稳定。经动物体内试验表明,TLP_1、TLP_2具有较强的去纤抗凝作用,TLP_3、TLP_4不显示抗凝作用,而显示出较强的促凝血作用。结果表明,尖吻蝮蛇毒与美洲矛头蝮蛇毒一样,同时含有去纤酶(Defibrase)和蛇毒凝血酶(Hemocoagulase)。这一结果对该蛇毒的研究与应用是很有意义的。     

Effect of A, E, C, P vitamin complex on erythrocyte hemocoagulation properties and platelet aggregation in thrombinemia]

The protective effect of A, E, C, P vitamin complex has been experimentally proven to display in a decrease of animal death rate and in limiting the intensity of hemocoagulation shifts in thrombinemia. This effect is stipulated by a decrease in thrombocyte aggregation and in coagulation activity and by the increase of erythrocyte deformation properties. These changes seem to be caused by the effect of vitamins on the phospholipid spectrum, electrolyte transport of ATPases and erythrocyte membrane stability.     

Method of dissecting peripheral nerve sheaths with an ultrasonic microscalpel that does not disturb neural conduction

A new method for dissection of the nerve sheaths by an ultrasonic microscalpel was tested in in-vivo experiments with the cat saphenus nerve. The compound nerve action potential consisting of A beta, A delta and C waves did not change after successive one-cm long dissections of the major nerve sheaths, epineurium and perineurium, demonstrating innocuous character of the method. Not deep plunging of the ultrasonic scalpel into the nerve, hemocoagulation when dissecting as well as drastically reduced mechanical efforts are the principal advantages of new method.     

Constitutional features of the reaction of the hemostatic system to a physical load

This study involves 72 young men with various levels of working efficiency and elucidates the relationship between human morphological constitution by the type of age-related evolution of the organism and parameters affecting hemostasis. As suggested by V.G. Shtefko, the measured value of the trochanteric index (TI) is compared to the reaction of the hemostatic system to graded moderate veloergometric load. It was found that decreased coagulability and activation of fibrinolysis take place in untrained men with high TI values in response to a load, while stimulation of blood coagulation and inhibition of its fibrinolytic activity occurs in men with low TI values. There is a significant correlation between the TI value and reaction of the hemocoagulation system to a load. Under the impact of a load, hemocoagulation and fibrinolysis are stimulated in persons with a relatively high working efficiency and high TI values, and coagulation is inhibited and fibrinolysis is more often stimulated in those with low TI values. Our conclusion is that a more favorable and stable response of the hemostatic system to a physical load takes place in subjects with the normo- and hyperevolutive constitutional types in conditions of both low and relatively high working efficiency levels. Low TI values, combined with low working efficiency level, are a risk factor for the development of thromboembolism complications in men, and these may be provoked by physical activity.     

Dependence of haemostasis system response from initial blood coagulation activity under total joints replacement

Effect of the initial state of the plasma hemostasis on the hemocoagulation changes after the total arthroplasty surgery was studied in 100 patients with osteoarthritis. Indicators of coagulation, fibrinolysis, and physiological anticoagulants were determined before and after completion of the surgery, at days 1, 3, 7, and 13-14 postoperatively. Increased coagulation activity befor surgery enhanced blood clotting within three days after the surgery. Enhanced consumption of physiological anticoagulants reduced the ability to recover their level a week after arthroplasty. The raised activity of the fibrinolysis inhibitor retained the effect during three postoperative days. Initial abnormalities in plasma hemostasis enhance blood coagulation dysfunction caused by surgical intervention on the large joints.     

Differential diagnostic performance of Rose Bengal Score Test in Sjøgren's syndrome patients

Aim of the study was to evaluate the diagnostic performance of the Rose Bengal score test for Sj?gren's syndrome (SS), and to explore differences between other tests and examinations. All participants were examined, including (but not limited to) unstimulated (UWS) and stimulated (SWS) whole saliva, labial gland biopsy (LGB or focus score), ophthalmologic questionnaire (ocular surface disease index OSDI) and objective tests: Schirmer test 1 (Sch. 1), Schirmer test 2 (Sch.2), Tear Break-up Time (TBUT) test and Rose Bengal score (RBS). Data were analyzed using Mann Whitney U-test, Receiver Operating Characteristic analysis, with specificity and sensitivity calculations and Spearman's correlation test. ROC curves showed a poor diagnostic performance of TBUT and OSDI. Sch. 1, Sch.2 and LGB all exhibited a high diagnostic performance. RBS exhibited the best performance (sensitivity 100,00; specificity 100,00; AUC 1,000). Study reveals the scarce reliability of TBUT, OSDI and Sch.1, and emphasizes RBS as the test of choice in the SS diagnosis.     

Cervical smear adequacy: cellularity references were found to increase both interobserver agreement and unsatisfactory rate

Objectives:  To determine the degree of interobserver variation in the assessment of conventional cervical smear adequacy as defined by The Bethesda System (TBS) 2001, and to determine the effect of using reference images of known squamous cellularity when performing squamous adequacy assessments.
Methods:  Experimental pre-test/post-test design utilizing 70 conventionally prepared cervical smears. Sample smears containing scant squamous cellularity were independently rated on two occasions by six cytotechnologists. Time 1 was without the use of reference images, and Time 2 was aided by cellularity reference images. The κ statistic was used to compare rater agreement.
Results:  The level of agreement increased from an average κ of 0.26 (SD 0.10) for Time 1, to an average κ of 0.40 (SD 0.15) for Time 2. The difference in mean κ values at the two assessments was statistically significant ( t  = 3.71; P  = 0.002). Unanimous agreement among the raters was observed for 15 samples (21.42%) at Time 1 (only one of which was classified as unsatisfactory) and 21 samples (30.00%) at Time 2 (12 of which were classified as unsatisfactory).
Conclusion:  Interobserver agreement increased after cellularity reference images were implemented. Using TBS 2001 squamous adequacy criteria and images of known squamous cellularity as references resulted in a decreased number of smears reported as satisfactory.     

Effect of fluorochromes on bacterial surface properties and interaction with granular media.

Simple, efficient, and safe tagging methods are desired in short-term microbial transport studies such as in the study of filtration systems for water and wastewater treatment. Suitability of selected fluorochromes as bacterial tagging agents in transport studies was evaluated on the basis of stability of stained cells and the effect of staining on bacterial surface characteristics and interaction with granular media. Surface properties were characterized by zeta potential and microbial adhesion to hydrocarbons. The effect of staining on interactions between bacteria and porous media was evaluated in terms of removal of bacteria in batch adsorption tests using sand coated with aluminum hydroxide to enhance adsorption. The DNA-specific fluorochrome 4',6-diamidino-2-phenylindole (DAPI) had generally negligible effects on bacterial surface properties and interaction with sand, as indicated in batch adsorption tests using pure cultures (Escherichia coli or Acinetobacter sp.) and wastewater bacteria. Cells stained with DAPI were stable for 48 h at 4 or 20 degrees C. Other nucleic acid fluorochromes tested had different but significant effects on bacterial cells and produced less stable fluorescence. Since transport through porous media is modulated by surface properties, it may be concluded based on these results that the choice of fluorochromes is critical in microbial transport studies. DAPI appeared to be a promising tagging agent. Time dependence of fluorescence of stained cells may limit the use of fluorochrome-tagged cells in long-term transport studies.