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PubMedDate not supplied

A critical review of the literature on ratings scales for perceived exertion.

The study of human performance and perceived exertion during physical activity has been an area of considerable interest and research for over 50 years. This review considers the evidence of many investigators who have been researching the physiological basis as well as non-physiological basis for the ratings of perceived exertion. During low levels of activity, physical perception in the working muscles appears to be the primary stimulus for effort perception. When work intensity exceeds the lactate threshold, incremental elevations in blood lactate complement peripheral input from the neuromuscular mechanisms. Once a critical absolute ventilatory threshold is reached, central input also contributes to effort perception. In most instances, peripheral input predominates over central cues, although it has been shown that pronounced central cues may dominate the perception of effort. Central (heart rate, VE, VO2) or local (muscle and blood lactate, adenosine triphosphate, creatine phosphokinase, glycogen) cues highlighted in these studies demonstrate both the complexity of effort perception, and the need for better understanding of the physiological components upon which it is based. Athletes have been shown to have a greater tendency to reduce perceptual ratings than their non-active counterparts. In view of these observations, it is apparent that a theoretical framework based upon physiological and psychological considerations may exist to support the concept of training-induced alterations in perceived exertion. This appears to be particularly true in higher ranges of exercise intensity. Part of the problem in reaching a conclusion on the issue of perceptual ratings trainability centres upon the agreement on what should be recognised as a significant decrement in perceived exertion. It is concluded that there is considerable variation in the findings of the literature and that any reported variations in performance may well be greatly influenced by intersubject variability, the type of exercise, and nutritional status of subject. Further research is required to understand this issue better.

Aerobiosis↗

PubMed1981

Fall in skin temperature during exercise observed by thermography.

Monochromatic and colored thermographies were used to visualize skin temperatures during exercise without involvement of sweating. Skin temperature began to fall immediately at the onset of exercise, remained low during exercise and rose rapidly after cessation of exercise. Increased work intensities produced a proportional fall in skin temperature and greater surface area of lowered temperature.

Adult↗

PubMed2006

The synthesis and antiviral properties of acyclic nucleoside analogues with a phosphonomethoxy fragment in the side chain.

Acyclic nucleoside analogues bearing phosphonomethoxy residues in the side chain (ANP) attract much attention due to a very beneficial combination of biological properties. Intensive work of organic chemists during the last two decades resulted in a large panel of new compounds that were evaluated as potential antiviral drugs. Herein, we present an overview of major chemical structures within the group of acyclic nucleoside analogues containing phosphonomethoxy side fragments and describe main aspects of their synthesis and antiviral potential. We also describe progress in "prodrug" approaches applied to this chemical group to improve pharmacokinetic profiles of the potential candidates. Chemical modifications in the molecule of parental ANP aimed at blocking of phosphonate charges resulted in a set of promising derivatives, two of which have been recently approved for treatment of hepatits B (Hepsera) and HIV (Viread). The preparation, antiviral properties and some aspects of metabolic transformations and pharmacokinetics of ANP prodrugs are discussed.

Animals↗

PubMed2006

The role of prostaglandins in liver ischemia-reperfusion injury.

Ischemia reperfusion (IR) of the liver is a multifactorial process that, at least in part, is responsible for the morbidity associated with major liver surgery under occlusion of the portal triad with the Pringle maneuver, total vascular exclusion or after liver transplantation. Surgeons are confronted with IR injury (IRI) more often than they anticipate. Although the human body has its own defense system, understanding the pathophysiology of IRI is essential for the surgeon in preventing and/or treating the reperfusion injury in common clinical practice. Several endogenous mechanisms exist to overcome IRI and a large number of pharmacological agents have also been found to confer protection against ischemic injury in the liver. They either blocked the injurious pathways directly or they subjected the liver to preconditioning. Prostaglandins (PGs) are a group of compounds derived from unsaturated 20-carbon fatty acids, primarily arachidonic acid, via the cyclooxygenase (COX) pathway. They are short-lived, hormone-like chemicals that regulate cellular activities on a moment-to-moment basis and are produced in most tissues of the body, although the liver has emerged as the major organ participating in the synthesis, degradation and elimination of arachidonate products of systemic origin. PGs are released through the prostaglandin transporter on the cell's plasma membrane. During the last decade intensive work on the cytoprotective effects of PGs on livers suffering from IRI have been well documented. Prostaglandins confer their protective effects on IR-injured livers mainly by inhibiting the generation of reactive oxygen species, preventing leukocyte migration, reducing the synthesis or production of membrane degradation products, improving hepatic insulin and lipid metabolism, and regulating the production of inflammatory cytokines and cell adhesion molecules. Production of PGs have been found essential also soon after partial hepatectomy for hepatocyte proliferation.

Animals↗

PubMed2006

Genetics, gene expression, and targeted therapies in chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) represents the most common leukemia among adults in the Western countries. CLL is a remarkably diverse disorder following an extremely variable clinical course. Some patients have an indolent disease that may never require treatment. In others a progressive clinical course is rapidly fatal. CLL affects mainly elderly individuals, but about a third of patients are less than 60 years of age at diagnosis. Traditionally, the therapeutic procedures were aimed at palliation, but over the recent years highly effective and potentially curative approaches such as combined antibody-chemotherapy and autologous or allogeneic stem cell transplantation have been developed. In parallel there has been progress in the understanding of pathogenesis and outcome prediction. The cornerstones to estimate prognosis are the clinical staging systems of Rai and Binet. To refine outcome prediction for individual patients there has been intensive work on biological factors of potential prognostic relevance. Among these, the genetic characteristics of the CLL cells that can be divided into genomic aberrations and the mutation status of the variable segments of immunoglobulin-heavy chain genes (VH) have attained considerable importance. In addition, data on gene expression of CLL cells are accumulating which further characterize the CLL subgroups. In this context, the expression of ZAP-70 has been recognized a useful surrogate marker to predict the VH mutation status and outcome of CLL patients. At present, targeted therapies are focused on humanized antibodies that bind proteins expressed on the surface of CLL cells. The most prominent agents of these are the anti-CD52 antibody alemtuzumab and the anti-CD20 antibody rituximab, which are currently being tested in clinical trials. To identify CLL-specific gene expression products as candidates for targeted therapies will be an important part of CLL research in the next years.

Animals↗

PubMed1998

Reduced serum levels of ALT and GGT and high carbohydrate intake among workers exposed to toluene below the threshold limit values.

We have found decreased serum alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) levels in human males exposed to toluene at low levels, suggesting that toluene exposure or related factors in lifestyles were likely to have lowering effects on serum ALT and GGT activities between toluene-exposed and the control subjects. The present study was attempted to investigate whether there is any difference in nutrient intakes between the two groups. Biochemical results were also analysed together with nutrient intakes. In agreement with our previous reports, the present data also provided significant evidence of lowered serum ALT and GGT activities in toluene-exposed males after age matching (p < 0.05). Energy intakes from carbohydrate, fat and protein were 64.6%, 22.5% and 12.9% in the toluene-exposed group and 62.0% (p < 0.05), 24.8% (p < 0.05) and 13.2%, respectively, in the controls. Multiple regression analysis indicated that carbohydrate, protein and energy intakes are significantly associated with toluene exposure. No significant differences in alcohol consumption, tobacco use, work intensities and physical activities were found between the two groups. The present results suggest that the toluene exposure at levels generally considered to be safe, probably have some biological effects on the liver and related organs.

Adult↗

PubMed2006

Characteristics of lifestyle and health status of workers in small-scale enterprises in Japan.

This study was conducted to clarify the characteristics of small-scale enterprises (SSEs) with fewer than 50 workers, which employ 62.2% of all Japanese workers. Subjects were 71,183 workers employed at 1,761 workplaces in Tochigi, Japan, in 2002. Frequencies of abnormal lifestyle and health check-up data were described according to the category of the enterprise. Adjusted odds ratios (ORs) of the abnormal findings were calculated by logistic regression analysis. Dose-response relationships were calculated by trend tests. The frequency of abnormal findings was higher in SSEs than in other categories of enterprises. The ORs of work intensity, alcohol consumption, current smoker, and the Brinkmann index were higher in SSEs than in large-scale enterprises (LSEs) and were also significant in trend tests. The ORs of audiometry, hypertension, glucose in urine and ECG in males and females, BMI, liver function, lipid metabolism, and blood sugar in females, chest X-ray, and anemia in males were higher in SSEs. Audiometry, hypertension, anemia, ECG in both males and females; chest X-ray, and glucose in urine in males, and liver function, lipid metabolism and blood sugar in females showed significant results in trend tests. Overall health and healthy lifestyle in SSEs were worse than in LSEs.

Commerce↗

PubMed1990

Effect of sodium bicarbonate on racing Standardbreds.

Twenty-two Standardbred horses in race training were used in a crossover experiment to determine the effect of oral sodium bicarbonate (NaHCO3) administration on performance and metabolic responses to a 1.6-km (1-mile) race. Horses were paired and one horse in each pair was treated with either NaHCO3 (300 mg/kg BW) or a placebo, 2.5 h before they raced against each other. Each horse was scheduled to compete in two races, approximately 1 wk apart, one on each treatment. Horses always raced in the same pairs. Fourteen horses successfully completed both races. Jugular blood samples were obtained 1.5 h after treatment (rest), immediately before racing, 5 min post-race and 15 min post-race. In six horses, blood samples also were obtained 30 min post-race. Race times averaged 1.1 s faster after NaHCO3 treatment (P less than .1). Sodium bicarbonate treatment also elevated blood pH (P less than .05). In the horses sampled 15 and 30 min post-race, blood lactate disappearance was faster with the NaHCO3 treatment (P less than .05). The NaHCO3 may delay the fatigue precipitated by i.m. acidosis. Because other factors may limit performance (musculoskeletal soundness, cardiovascular and respiratory ability), NaHCO3 would not be expected to enhance the performance of all horses. However, the effect of NaHCO3 on lactate clearance may have implications for all intensively worked horses; because lactate and the associated hydrogen ions are believed to cause muscle damage and soreness, any mechanism to increase their removal rate could benefit the equine athlete.

Acid-Base Equilibrium↗

PubMed2000

Effect of short-term feed restriction and calorie source on hormonal and metabolic responses in geldings receiving a small meal.

The metabolic effects of short-term feed restriction and dietary calorie source were studied in horses receiving high-roughage or high-concentrate diets. Four Thoroughbred geldings were assigned to four treatment groups in a 4 x 4 Latin square experiment. The four treatments were 1) a nutritionally adequate high-roughage ration (70% roughage, 30% concentrate; AHR), 2) a nutritionally adequate high-concentrate ration (40% roughage, 60% concentrate; AHC), 3) 70% of the intake of the AHR diet (RHR), and 4) 70% of the intake of the AHC diet (RHC). Diets AHR and AHC were designed to meet the caloric need of horses undergoing moderately intense work. Blood samples were taken on the first 7 d of each period for analysis of serum T4 and T3 concentrations. On d 9 of each feeding period, each horse was fed 1.0 kg of oats as the morning meal. Jugular blood was sampled before and immediately after, as well as at 30 min after, completion of the meal and subsequently every hour for 7 h. Daily serum T4 and T3 concentrations were not affected by day, feeding level, or diet composition. Meal feeding produced an increase (P < 0.01) in T4 and T3 concentrations when horses were adapted to the AHR and AHC diets but not the RHR or RHC diets. Thyroxine concentrations were lowest (P < 0.05) when horses were adapted to the AHC diet. Glucose (P < 0.05), insulin (P < 0.01), and NEFA (P < 0.01) concentrations were higher in response to the meal when horses received RHR than for the other diets. These results indicate that nutrient restriction alters responses to meal feeding in horses and that this response may also be affected by the dietary roughage:concentrate ratio.

Animal Feed↗

PubMed1992

Arterial blood gases and brain oxygen availability following infusion of intratracheal fluorocarbon neat liquids.

Eight adult New Zealand Swiss rabbits (3-5 kg) having previously implanted chronic bilateral platinum electrodes in the visual cerebral cortex and subcutaneous silver reference electrodes were tranquilized and monitored in multiple 2-3 hour sessions using voltammetric techniques. Six of these were given intratracheal neat liquid fluorocarbons ranging in boiling point from 132 degrees C to 215 degrees C at doses of 2 or 4cc/kg. Each animal received only one fluorocarbon liquid. Two additional rabbits were match-studied as controls. Half of the rabbits have survived more than five months. Both controls and two experimental rabbits were sacrificed after more than seven months due to gastric hairballs. The period of daytime monitoring sessions, when cathodic brain oxygen currents (aO2), arterial blood gases and pH were obtained, was between 34 and 263 days. In some animals the arterial pCO2 was increased during the first week but the pO2 and pH remained nearly normal in all eight animals throughout. The two best fluorocarbons for liquid breathing on the basis of this limited but intensive work are F-methyldecalin and F-5,6H-dec-5-ene (F44E).

Animals↗

PubMed1993

Functional testing of human dopamine D1 and D5 receptors expressed in stable cAMP-responsive luciferase reporter cell lines.

A large number of G-protein coupled receptors are known to modulate adenylyl cyclase activity. In order to find new compounds modulating the activity of specific receptor subtypes we developed a cellular screening system that measures the biological activity of drugs acting on receptors rather than merely their binding characteristics. The activity of the receptor coupling to the cAMP signal transduction pathway was measured via transcriptional activation of a reporter gene. A chinese hamster ovary cell line was stably transformed with a reporter plasmid containing the firefly luciferase gene under the transcriptional control of multiple cAMP responsive elements (CRE). This CRE reporter cell line exhibited 20 to 30-fold induction of luciferase activity upon stimulation of adenylyl cyclase with forskolin, but did not respond to dopamine agonists. Stable test cell lines were developed by transfecting reporter cell lines with human dopamine D1 and D5 receptor genes, respectively. Treatment of these test cell lines with dopamine receptor agonists and antagonists modulated the luciferase expression in a dose-dependent manner. The rank of potency of dopamine receptor agonists and antagonists was in agreement with reported data obtained from binding studies. The non-isotopic assay can be performed in microtiter plate format and is far less work intensive than the determination of adenylyl cyclase activity by direct cAMP measurement. This technology could also be utilized for discovery of new classes of compounds, e.g. allosteric effectors or non competitive ligands.

Animals↗

PubMed2001

An alternative management of older children with persisting communication problems.

Speech and language deficits frequently implicate accompanying psychosocial problems (such as low self-esteem). An alternative management approach is described which adopts a holistic paradigm and provides a unique opportunity for intensive work on communication within a supportive environment. The residential programme for 8-14 year olds with persistent communication difficulties incorporated cognitive, emotional and psychosocial dimensions of communication, co-ordinated with work on speech features. Although the programmes were developed for children with cleft palate, they have potential for benefiting a wide range of communication impairments of different aetiologies. A forthcoming manual with resource material developed by the research team will be used in studies across these groups.

Adolescent↗

PubMed1999

Physical training augments plasma catecholamines and natural killer cell activity.

To elucidate the effects of a 10-week exercise training period on physical fitness and plasma catecholamine concentration at rest, and on natural killer cell activity in young healthy untrained females, subjects (20-22 years old. N = 16) carried out physical training by a protocol which consisted of treadmill jogging at a work-intensity of 50% of their VO2max, two hours a day three times a week for ten weeks. VO2max was increased significantly from 33.1 +/- 3.4 ml/kg/min to 38.3 +/- 6.6 ml/kg/min by the ten weeks of physical training (P < 0.005), and natural killer cell activity was also increased significantly from 31.9 +/- 14.3% to 46.4 +/- 18.4% (P < 0.05). The concentrations of epinephrine and norepinephrine before and after physical training were 18.3 +/- 8.7 pg/ml and 20.4 +/- 8.9 pg/ml, and 134.1 +/- 52.2 pg/ml and 248.1 +/- 106.8 pg/ml (P < 0.005), respectively. Changes in norepinephrine and epinephrine correlated with the change in VO2max (r = 0.780, P < 0.005; r = 0.556, P < 0.05). While the change in natural killer cell activity correlated with the change in epinephrine (r = 0.623, P < 0.01), the correlation of the change in natural killer cell activity with change in norepinephrine did not reach statistical significance (r = 0.497, P = 0.0503). From these results we concluded that physical training augments plasma catecholamine levels and natural killer cell activity at rest in young healthy females.

Adult↗

PubMed1999

Injuries caused by antipersonnel mines in Croatian Army soldiers on the East Slavonia front during the 1991-1992 war in Croatia.

During the war in Croatia, antipersonnel mines were mostly laid without plan by both sides, with no minefield layout, especially on the East Slavonia front. A group of Croatian disabled war veterans wounded by antipersonnel mines at the East Slavonia front from June 1, 1991, to September 1, 1992, were analyzed. The front line between the Croatian Army units and Serbian paramilitary units mostly ran along a lowland, partially swampy and wooded ground, convenient for large-scale laying of antipersonnel mines, especially so-called surprise mines. Fifty-seven soldiers suffered injuries caused by antipersonnel mines, 27 (47.4%) of them by pressure-activated mines and 30 (52.6%) by pull-action mines. The severity of wounds was assessed according to the Abbreviated Injury Scale (AIS). In the group of patients with wounds inflicted by pressure-activated mines, the mean AIS score was 4.0 +/- 0.7, with injuries to the lower extremities (mostly feet) ranging from foot-mutilating defects to partial lower-leg amputation. In the group of patients with injuries caused by pull-action mines, the mean AIS score was 3.0 +/- 0.9, indicating relatively minor injuries of different types according to the mechanism of wounding and localization. A failure to comply with minelaying regulations made protection impossible and resulted in a relatively high proportion of the wounded. The same problems are now encountered on mine removal. According to estimates, at least 10 years of intensive work of 2,000 to 3,000 trained experts will be required to clear some 2 million mines laid all over the area.

Abbreviated Injury Scale↗

PubMed1976

[Comparison of the contractile function of the heart in hares and rabbits under conditions of relative rest and under resistance loading].

A comparison was conducted between the contractile function of the heart of hares and rabbits at rest and under isometric contractions regimens, and under such conditions the concentration of ATP and its breakdown products was studied in the myocardium of both species. It was demonstrated that the cardiac muscle of hares adapted by the evolution to the performance of intensive work does not possess any increased ability of developing systolic tensions, or any increased power of the ATP resynthesis apparatus. The advantage of such a heart-- its ability to pump an increased blood volume -- must be ensured by some different mechanism that requires still further investigations.

Adaptation, Physiological↗

PubMed1992

The critical attributes of leadership.

The final decade of this century is a period of unprecedented change that by all indicators will continue unabated well into the next millennium. This article explored some elemental and immutable truths about leadership, management, communication, and negotiation essential to organizational success, particularly during periods of accelerated change. The case is made for a level of integrity, ethical conduct, and self-control to match the technical competence essential for managerial success in a technologically intensive work environment. These attributes and skills coupled with a widening scope of institutional vision are critical to sustained leadership and growth in an unstable world. Those without these abilities will be diminished in their capacity to communicate or negotiate. Hence, they will be thwarted or powerless to create task attraction, to effect change, or to promote excellence. These lessons are applicable to the dynamic changes occurring within the health care industrial complex, including health information management.

Communication↗

PubMedDate not supplied

Reengineering managed behavioral healthcare.

Reengineering is an industrial method for rethinking and redesigning basic business processes in order to improve performance and lower cost. Just as many of the corporate clients of managed behavioral healthcare companies go through reengineering initiatives, behavioral healthcare needs to streamline its production processes, in order to deliver services that are high quality but affordable. Traditional, cumbersome, bureaucratic and labor-intensive work processes must be reexamined. This article reviews basic principles of reengineering in the context of the evolving managed behavioral healthcare industry, defines ten core processes for managed behavioral healthcare companies and then illustrates how reengineering methods can be applied to two intermediate processes: "manage access" and "manage network."

Clinical Protocols↗

PubMed1998

Hospitals deliver reduced cesarean rates.

The U.S. cesarean rate remains at about 22% of babies, but national goals say the rate should be more like 15%. A collaborative group of hospitals worked intensively for nine months to reduce rates by 25%. Issues addressed included managing pain more effectively, educating pregnant women, and avoiding admissions for false labor.

Benchmarking↗