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At least 865 records · Page 48Linked to original sources
PubMed1986

Speleotherapy: a special kind of climatotherapy, its role in respiratory rehabilitation.

Speleotherapy, the use of the climate of caves, is an accepted but not widely known therapeutic measure in the treatment of chronic obstructive airway diseases. This study summarizes the therapeutic experiences of more than 4000 patients who were treated in a 10-year period in a hospital-cave complex in Tapolca, Hungary. A sharp and long-lasting clinical improvement and a significant recovery from airway obstruction could be observed in the overwhelming majority of patients. It is established that the microclimate of some caves can beneficially affect these disorders, but the cave should be considered as an optimal environment for complex respiratory rehabilitation.

Asthma↗
PubMed1996

Effects of supplemental shade on thermoregulatory response of calves to heat challenge in a hutch environment.

Holstein (n = 12) and Guernsey (n = 6) calves, housed in hutches, were used to evaluate the complex relationships among external environment, housing microclimate, and thermal status of calves. The study was conducted during the summer; 9 calves were housed in hutches under supplemental shade, and 9 calves were maintained in hutches under direct sunlight. Environmental and calf temperatures were measured twice daily at 0700 and 1500 h, which included determinations of air temperature, inner and outer surface temperatures of the hutch, rectal and skin temperatures of the calf, and respiration rate. Outer and inner surface temperatures of the hutch were lower under supplemental shade. Hutch air temperature was highly correlated with inner surface temperature and therefore was lower in the shaded environment. During the p.m. period, when heat stress was highest, calves housed in a shaded hutch environment had lower skin temperatures and respiration rates than did unshaded calves. Body temperature and respiration rates increased less for calves in shade than for calves in sun. These data define the relationship between the calf and the environment. Supplemental shade diminished the severity of heat stress experienced by calves that were housed in hutches during the summer.

Animals↗
PubMed2026

Multi-locus allelic architecture underlying natural variation in leaf rolling in japonica rice.

Leaf rolling is a key component of rice canopy architecture that affects light interception, microclimate formation, and planting density. The contribution of naturally occurring allelic variation to quantitative variation in leaf rolling within cultivated rice remains poorly understood, while extreme leaf rolling caused by loss-of-function mutations often results in detrimental pleiotropic effects. Herein, we examined how multi-locus allelic variation contributes to natural variation in leaf rolling within japonica rice. Leaf rolling was quantified based on the leaf rolling index (LRI) using a panel of 201 japonica accessions. The phenotype was transformed using the Yeo-Johnson method to reduce strong right skewness and improve the distributional properties of the data, thereby facilitating subsequent regression modeling. Haplotype analyses were performed for previously reported leaf rolling-associated genes and genome-wide association study (GWAS) lead loci, leading to the identification of five loci exhibiting substantial haplotype-dependent phenotypic variation. Phenotypically defined allelic groups represented these loci were subsequently evaluated using multiple linear regression (MLR), with the first two principal components derived from genome-wide SNP data included as covariates to account for population structure. The final MLR model identified four loci (qALR1, OsYABBY1, OsSLL2, and OsSRL10) as the independent contributors to leaf rolling variation, collectively explaining 21% of the variance in the transformed phenotype after accounting for population structure. Model diagnostics and ten-fold cross-validation supported the statistical validity of the framework and indicated stable model performance across validation folds. Analysis of multi-locus allelic combinations showed 13 distinct configurations that clustered into three phenotypically differentiated groups. This reflected the cumulative dosage of high-leaf rolling alleles. Thus, the natural variation in leaf rolling in japonica rice is governed by the additive effects of multiple moderate-impact loci. The multi-locus allelic framework established here provides a statistically sound and biologically interpretable basis for dissecting polygenic canopy traits and practical guidance for developing genetic materials aimed at optimizing rice plant architecture.

cross-validation↗
PubMed1984

Internal temperature of decomposing duck carcasses in relation to botulism.

Under spring conditions (mean daily maximum 22 C, mean daily minimum 9 C), the temperature within duck carcasses paralleled air temperature for 3 days; on days 4 and 5 the internal temperature rose above 30 C for approximately 30 hr and maximum temperatures of 40-47 C occurred. This coincided with the period of maximum blowfly maggot activity in the carcasses. Carcasses screened from blowflies did not experience this period of high internal temperature. Under autumn conditions (mean daily maximum 13 C, mean daily minimum 1 C), the internal temperature of carcasses paralleled air temperature for approximately 2 wk. Following a warm day (23.5 C), maggots appeared in the carcasses and the internal temperature rose markedly higher than air temperature. Maggots moved into the soil on cold nights and reinhabited the carcasses during the day. The microclimate within maggot-infested carcasses appeared very suitable for growth and toxin production by Clostridium botulinum and this phenomenon may help explain the occurrence of botulism outbreaks during cool weather.

Animals↗
PubMed1999

[Preconditioning of calves].

A high frequency of diseases in the veal industry is caused by diseases which are induced by several factors which are caused or at least influenced by errors of management. In order to comply with the political goal of a diminution of the use of antimicrobials in the veal industry (ban of growth promoters), errors of housing and of nutrition, damaging influences of the microclimate and hazardous commercial substances should be eliminated. Further measures of prophylaxis are discussed.

Animal Husbandry↗
PubMed1999

[The role of associated factors in the evaluating the effet of local vibration influence].

Present measurement method of local vibration dose and of corresponding factors characterizes degree of unfavorable effects caused by those components in humans rather indistinctly, because of the following reasons: 1) considering muscular efforts put on a vibrating instrument, "vibration-force" complex incompletely accounts static load on flexor muscles of fingers, if those efforts referred to individual functional abilities; 2) work hardiness used in this method sometimes inadequately reflects value of static muscular efforts in "vibration-force" complex; 3) combined effect of cooling microclimate parameters are evaluated, rather inexactly.

Adult↗
PubMed1999

Behavioral, molecular and integrative mechanisms of amphibian osmoregulation.

Amphibian water balance has been studied at many levels of biological order. Terrestrial species must react to environmental cues that relate to water availability while some arboreal species have cutaneous skin secretions that can reduce evaporative water loss. The Indian tree frog. Polypedates maculatus, uses cutaneous secretions and wiping behavior to lower evaporation but also relies on moist microclimates to endure prolonged survival away from water. The related species, P. leucomystax, inhabits wetter forest habitats. Preliminary studies with this species are unable to demonstrate the expression of wiping behavior, indicating that arid habitats may be a powerful selective force for this behavior. Laboratory experiments on rehydrating toads in the genus Bufo indicate that animals are able to detect changes in barometric pressure and humidity that might result in the availability of water under field situations. Experiments with Bufonid species and with spadefoot toads, Scaphiopus couchi, show that the peptide hormone, angiotensin II, stimulates cutaneous drinking in a similar manner seen for oral drinking by other vertebrate classes. Amphibian tissues have long been used as a model for the study of basic physiological principles of epithelial ion and water transport. Recent progress with tissue cultures has provided information on the molecular structure of ion and water channels that can be applied to obtain a better understanding, at the molecular level, of ion and water balance strategies used by the wide variety of amphibian species. Terrestrial amphibians are more tolerant of dehydration than are other vertebrates and are able to store dilute urine in their urinary bladder. Toads appear to be able to detect the presence of water in their bladders in addition to the availability of water in their environment. Dehydrated toads are able to rehydrate very rapidly by the coordination of behavioral and physiological mechanisms to enhance cutaneous water absorption. The integration of behavior with cutaneous water gain, renal handling of ions and water and the role of the lymphatic system in overall water balance involves complex interactions between neural and hormonal factors. Experiments are summarized that describe the contribution of individual factors however much more information is needed before the nature of these interactions are fully understood.

Adaptation, Physiological↗
PubMed1999

H+-zwitterionic amino acid symport at the brush-border membrane of human intestinal epithelial (CACO-2) cells.

Transport of a number of dipolar amino acids (and the orally active antibiotic D-cycloserine) across the apical membrane of human intestinal epithelial (Caco-2) cell monolayers is mediated by a Na+-independent, pH-dependent transport mechanism. Relatively little is known about the mode of action of this transport system so to differentiate between pH dependence and proton coupling three experimental protocols were designed and tested. The results demonstrate, firstly, that it is the transapical pH gradient and its maintenance (rather than apical acidity alone) that is important in amino acid uptake. Secondly, Na+-independent uptake of seven dipolar amino acids (with pKa (-log of acid dissociation constant) values between 1 50 and 4 23) showed a similar dependence on apical pH (half-maximal uptake being observed at pH 5 99-6 20). Thirdly, the pattern of pH-dependent amino acid ([beta]-alanine) uptake is similar irrespective of whether the cationic substrate concentration is varied or constant, demonstrating no relationship between uptake and concentration of the cationic form of the amino acid. These observations demonstrate that the transport mechanism is a H+-zwitterionic amino acid symporter and suggest that the presence of a H+ gradient at the apical surface of the human small intestine (in the form of the acid microclimate) may be important in driving nutrient absorption.

Amino Acids↗
PubMed1998

[The respiratory system of workers employed in the casting and processing of copper].

The aim of the study was to examine the influence of work in exposure to copper on the respiratory system. The study was carried out in 267 men aged (x +/- SD) 40.6 +/- 7.2 yrs, workers of a colour metal mill. 134 of them dealt with casting and processing of copper (the mean weighed concentration of copper on work posts was below 0.05 mg x m-3) and 133, not employed in a contaminated environment, comprised the control group. The subjects were divided into five groups according to the degree of energy expenditure at work and, additionally cigarette smoking was taken into account. All subjects underwent medical examination and spirometry. However the mean values of the ventilatory parameters in the compared groups did not significantly differ (p > 0.05), the multivarious regression analysis has shown a decreasing trend of FEV1 and FVC with relation to the exposition to copper and tobacco smoking. The frequency of chronic bronchitis as well as of radiological changes was not increased. The authors conclude: 1. At copper concentration not exceeding the MAC, and an advantageous microclimate, this exposition only slightly diminishes the pulmonary ventilation and does not cause other comprehensible pulmonary pathological sequelae, especially chronic bronchitis. 2. Tobacco smoking is a favourable factor for the occurrence of chronic bronchitis.

Adolescent↗
PubMed1999

[Health-related absenteeism among workers employed in various work environments].

The state of health in working people is determined by a number of factors among which working conditions and the kind of job performed play undoubtedly a crucial role. The observation and analysis of trends in sick absenteeism may provide indirect information on health problems of the occupationally active population. The aim of the analysis presented was to define the magnitude and the causes of temporary work disability among workers employed in individual branches of the national economy, and finally to identify high risk groups of workers because of their employment in specific working conditions. The statistical material used as the basis for the calculation of absenteeism indicators embraced the data on the number of work disability days, derived from a 15 representative sample of punched cards, concerning certificates of temporary work disability. In order to accomplish the objectives of the analysis, the trends in sick absenteeism observed before 1989, the period preceding the structural changes and the transformation of Polish economy were taken into consideration. The analysis indicates that the level of sick absenteeism in the branches of the national economy (forestry, building construction, transport, industry) and the proportion of chronic diseases in its structure prove the effect of working conditions on the workers' health. Considering individual branches of industry, the highest levels of sick absenteeism are observed in the following branches: mining for men (5.61), non-ferrous metals for women (10.04) and men (4.95), ferrous metallurgy for women (9.99) and men (4.93), and petroleum products for women (11.76). The analysis of sick absenteeism in the branches selected in view of hazardous working conditions shows that: (1) in many branches chemical hazards in the work environment are responsible for an increased sick absenteeism due to diseases of the circulatory system, particularly among men, mental disorders and neoplasms, both among men and women, and complications of pregnancy among women; (2) physical work overload increases sick absenteeism mainly due to diseases of the musculoskeletal and peripheral nervous systems, as well as due to cardiac disease and arterial hypertension; and (3) hot microclimate contributes to sick absenteeism because of diseases of the circulatory system, including cardiac disease and arterial hypertension, particularly among men, as well as acute and chronic respiratory diseases.

Absenteeism↗
PubMed1999

The effects of wind and human movement on the heat and vapour transfer properties of clothing.

This paper integrates the research presented in the papers in this special issue of Holmér et al. and Havenith et al. [Holmér, I., Nilsson, H., Havenith, G., Parsons, K. C. (1999) Clothing convective heat exchange: proposal for improved prediction in standards and models. Annals of Occupational Hygiene, in press; Havenith, G., Holmér, I., den Hartog, E. and Parsons, K. C. (1999) Clothing evaporative heat resistance: proposal for improved representation in standards and models. Annals of Occupational Hygiene, in press] to provide a practical suggestion for improving existing clothing models so that they can account for the effects of wind and human movement. The proposed method is presented and described in the form of a BASIC computer program. Analytical methods (for example ISO 7933) for the assessment of the thermal strain caused by human exposure to hot environments require a mathematical quantification of the thermal properties of clothing. These effects are usually considered in terms of 'dry' thermal insulation and vapour resistance. This simple 'model' of clothing can account for the insulation properties of clothing which reduce heat loss (or gain) between the body and the environment and, for example, the resistance to the transfer of evaporated sweat from the skin, which is important for cooling the body in a hot environment. When a clothed person is exposed to wind, however, and when the person is active, there is a potentially significant limitation in the simple model of clothing presented above. Heat and mass transfer can take place between the microclimate (within clothing and next to the skin surface) and the external environment. The method described in this paper 'corrects' static values of clothing properties to provide dynamic values that take account of wind and human movement. It therefore allows a more complete representation of the effects of clothing on the heat strain of workers.

Bias↗
PubMed1999

[Pulmonary surfactant status in experimental dust-induced bronchitis based on the data from dynamic interphase tensiometry].

The disease was simulated by inhalation of dust containing 29% of free silica in Wistar male rats during 8 months. One group of the subjects was kept under 26-28 degrees C and other one--under 38-40 degrees C. Dynamic surface tension of lung tissue homogenate was studied by means of computer tensiometer MRT (Lauda, Germany). Interphase tensiometry precisely characterizes state of lung surfactant in experimental chronic dust bronchitis. Equilibrium surface tension and surface tension for 0.01 and 1 sec deteriorate during combined exposure to silica dust and heating microclimate. The studies demonstrated strong correlation between interphase tensiogram parameters and individual lipids content of lung surfactant. Surface tension is related to the state of lipids peroxidation in lungs and antioxidant systems.

Animals↗
PubMedDate not supplied

[Temperature of the skin in microvascular flaps].

Transferred free flaps by their defined vascular net improve the perfusion of the recipient region. Skin temperature depends on the skin perfusion, temperature conduction of the visceral organs, muscles and blood vessels, as well as on the heat loss by the evaporation and air convection in the environment. At the Clinic for Plastic Surgery and Burns and at the Institute of Hygiene of the Military Medical Academy, skin temperature of the transferred free flaps and the recipient region surrounding were analyzed and measured in controlled microclimate conditions. The analysis was performed in 31 subjects, 20.23 months after the free tissue transfer. The aim of the study was to determine the differences between the skin temperature of the transferred free flaps and the recipient region surrounding, as wall as of the donor's region surrounding. The results of the investigation revealed that skin temperature of the transferred free flaps was lower in 28 (90.3%) patients than the temperature of the donor's region surrounding. Skin temperature of the transferred free flaps was higher in 25 subjects (80.6%) than the temperature of the recipient region surrounding. Skin temperature of free flaps transferred to the foot and the lower leg was higher than the skin temperature of the recipient region surrounding but was also lower in the flaps transferred on the head. The temperature of the recipient region surrounding influenced the skin temperature of the transferred free flaps, besides the flap tissue perfusion.

Adult↗
PubMed1998

Detection of parasites in the environment.

The environmental route of transmission is important for many protozoan and helminth parasites, with water, soil and food being particularly significant. Both the potential for producing large numbers of transmissive stages and their environmental robustness (with the ability to survive in moist microclimates for prolonged periods of time) pose persistent threats to public and veterinary health. Increased demands made on natural resources increase the likelihood of encountering environments and produce contaminated with parasites. In the last 30 years, endemic and epidemic waterborne and foodborne outbreaks in developed countries have led to a reappraisal of conventional isolation and detection methods. While these methods have proved invaluable in our understanding of environmental transmission routes for helminths, they have been less effective for the parasitic protozoa. Robust, efficient detection, viability and typing methods are required to assess risk and to further epidemiological understanding. Greater awareness of parasite contamination of our environment and its impact on health has precipitated the development of better detection methods. Currently, nowhere is this more apparent than with Cryptosporidium, with a broad range of immunological, microscopical and molecular methods available. The upsurge in molecular techniques, particularly the polymerase chain reaction, for determining occurrence and viability have brought with them the added benefits of increased sensitivity and specificity, yet many methods still have to be shown to address these issues consistently in the field. Rapid commercialization of reagents and standardization of methods provide consistency. The advances identified in non-destructive and destructive methods for the protozoa have application for helminths and emerging pathogens and should determine the importance of the matrices involved in the environmental transmission of parasites, further safeguarding public and veterinary health.

Animals↗
PubMed2000

[Microbiological threat from buildings and rooms and its influence on human health (sick building syndrome)].

In buildings we can observe many different strains of bacteria, over 400 species of mould fungi, many strains of fungus causing the rotting of wood and wood like materials, many species of algae, aphids, and other types of growths and seed plants and also over 30 types of mites especially those seen in house dust. Buildings, especially their interiors have a very specific microclimate. Within it areas of so called ecological lows are formed in which conditions for settlement, growth and reproduction of these organisms take place. A building, which is a hazard to the health of its residents, is called a "sick building" from the term "sick building syndrome". The incidence and development of some types of mould fungus is associated with the production of very toxic metabolites which are called secondary metabolites i.e. mycotoxins. Long term human, especially in relation to children, contact with the species producing the most potent mycotoxins like aflatoxin--Apergillus flavus, ochratoxins--Aspergillus ochraceus, rubratoxins--Penicillium rubrum or strachybotrytoxins--Strachybotrys chartarum may even be the cause of death. Mould fungus or just mould is a saprophytic fungus derived from many different systemic groups (Mucor, Aspergillus, Penicillium, Fusarinum). Fungi can produce lethal mycotoxins such as: alternariol, aflatoxins, gliotoxins, ochratoxins, nivalenol, cytinine, dicumarol, rugulosine, trichoviridine and about 200 more which considering their mutagenicity are potentially dangerous to humans, animals, flora and microorganisms. Research which was begun by Prof. Julian Aleksandrowicz and Prof. Bolesław Smyk in 1970 and 1971 showed that the so called "leukaemia houses" of leukaemia victims had an abundance of toxinogenic fungus in them, particularly the most potent fungus which turned out to be Aspergillus flavus. Toxinogenic funguses are abundant in many living spaces and cellars in older and also in new housing. Mycotoxins have been shown to be very toxic and harmful and it is no wonder that many inhabitants of these living spaces are constantly ill, mainly upper respiratory tract infections, lethargy, constant headaches, nausea and a general ill feeling. Inhabiting these living spaces for a considerable period may lead to cancer.

Adult↗
PubMed1975

[Transport of patients by airlines].

The problems of transporting patients on normal flights are examined. The first section describes the conditions of the plan's microclimate which might affect the health of passengers conditions which are obsolute contraindications for flying are also listed. More detailed analysis is applied to problems regarding the air transport of pregnant women, immature children and heart cases. The effect of hyperventilation and the anxiety state on flight passengers is then studied. To conclude, statistics on patients transported on airline flights and on the influence of flying on the course of diseases are reported.

Aerospace Medicine↗
PubMed2001

Age structure of a population of Ixodes ricinus (Acari: Ixodidae) in relation to its seasonal questing.

Three sites in south west Scotland, each having one deciduous and one coniferous woodland with populations of roe deer, were sampled over three years for Ixodes ricinus Linnaeus ticks using cloth drags. Nymphs and adult ticks were age graded by dissection of gut and Malpighian tubules and staining for lipid with Sudan red. Temperature and relative humidity were recorded in developmental and questing microclimates. Two annual cohorts of both nymphs and adults were found. For both instars one cohort became apparent in early spring and the other in autumn. The timing of the cohorts of nymphs corresponded to peaks of numbers questing, but neither females nor males had any clear seasonal pattern of questing. The maximum life of questing nymphs and adults was three to four months. Nymphs and adults were found questing at all months of the year and at temperatures ranging from 3.5 degrees C to 29.3 degrees C. Questing of larvae in summer peaks of numbers was positively correlated with temperature and negatively correlated with relative humidity. These results are explained by a descriptive model which invokes behavioural and morphogenetic diapause. Tests of the model are discussed and it is proposed that the main adaptive advantage of the complex life cycle is to permit moulting and oviposition to occur at favourable summer temperatures in ticks that have engorged at any time of the year.

Age Factors↗
PubMed1975

[Chronic non-specific respiratory disease with reference to 926 cases].

This study has been compiled from the hospital records of 926 patients with chronic non-specific respiratory disease, i.e. asthma, chronic bronchitis and emphysema. The aims of the study were to ascertain the role of age, allergy, family history, cigarette smoking, social class and occupation in the genesis of these diseases, and to investigate aggravating factors and the morbidity associated with these diseases. Asthma was found to occur in the younger age groups, allergy and family history being the outstanding aetiological factors in this disease. In chronic bronchitis the age factor is not decisive, and the influence of allergy, family history and the smoking of cigarettes is evenly distributed. Emphysema occurs mainly in later life, although 2 cases of younger onset with alpha1-antitrypsin deficiency were noted. In this disease, allergy and family history appear to be of lesser aetiological importance than the smoking of cigarettes. The majority of patients in all diagnostic categories fell into social group III (skilled workers) and most did work not associated with dust. In each diagnostic category, a certain number of patients were found in whom the factors of allergy, family history, cigarette smoking and general atmospheric pollution did not play a part. In these patients the possible role of the microclimate at the place of work is emphasised and warrants further study. The high prevalence, especially of asthma and chronic bronchitis, among housewives is stressed. Aggravating factors, i.e. humidity, irritating substances, temperature variations, dust, and type and locality of work, are shown to influence the symptomatology of asthma, bronchitis and emphysema. These diseases have a high associated morbidity, resulting in the loss of working days and in early retirement for the sufferers.

Absenteeism↗