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At least 523 records · Page 29Linked to original sources
PubMedDate not supplied

Pavlov as a psychologist. A reappraisal.

American psychologists are informed on Pavlov's work on conditional reflexes but not on the full development of his theory of higher nervous activity. This article shows that Pavlov's theory of higher nervous activity dealt with concepts that concerned contemporary psychologists. Pavlov used the conditioning of the salivary reflex for methodological purposes. Pavlov's theory of higher nervous activity encompassed overt behavior, neural processes, and the conscious experience. The strong Darwinian element of Pavlov's theory, with its stress on the higher organisms' adaptation, is described. With regard to learning, Pavlov, at the end of his scholarly career, proposed that although all learning involves the formation of associations, the organism's adaptation to the environment is established through conditioning, but the accumulation of knowledge is established by trial and error.

Animals↗
PubMed1988

Effects of exercise at high altitudes on young adults.

Outward Bound programs are carried out throughout the world, and many of these courses occur at altitudes above 3000 m (10,000 ft). As more knowledge is accumulated about health problems at high altitudes, exercise has been implicated as a factor contributing to acute mountain sickness in susceptible individuals. Thus, exercise conditioning programs occurring at high altitudes have come under scrutiny. Twenty-eight young men and women were enrolled in an Outward Bound course at an altitude over 3000 m for a 21-day period. Twelve of the 28 individuals developed shortness of breath, cough, or both by the third day of the course. Of these 12, seven had pulmonary function abnormalities: three having evidence of large airway involvement and four having findings of small airway involvement. The symptoms were not significant enough to interfere with acclimatization and the muscular conditioning aspects of the program. Although at altitudes between 3000 m and 4300 m, pulmonary function abnormalities of acute mountain sickness develop in a significant number of participants, the abnormalities were not significant enough to prevent persons from completing the course or achieving marked improvements in fitness measurements.

Adult↗
PubMed1978

[Development of combined methods of treatment of malignant tumors].

The term "combination treatment" should implicate various methods of treatment for malignant tumors scheduled beforehand. The combination treatment of malignant tumors is aimed at improving the immediate and late results. This is gained by means of reducing the biological activity of a tumor, both the effect of summation and potentiation of the action of different therapeutic measures being observed. The choice of methods and their sequence is determined by the prognosis factors, which incude the histological tumor structure, anatomical type of growth, the degree of its proliferation both within the range of proximate and remote zones of metastases spread, the general patient's state. At this stage it is difficult to elaborate the methods of combination treatment. The difficulties are conditioned by a variety of forms of many solid tumors, methodical difficulties and complexity of estimating an efficacy of different variants of treatment. Accumulating of knowledge should determine the a range of lesions subject to the combination treatment.

Academies and Institutes↗
PubMedDate not supplied

The use of pure FSH alone or in combination for ovulation stimulation in in vitro fertilization.

The experience of the Norfolk Program, from the beginning of 1981 until mid 1984, is reviewed. Two groups of patients are compared. The initial experience goes from the very beginning until early 1984 in which knowledge has accumulated; the patients treated afterwards up to mid 1984 where the previous experience was used to monitor them in a more accurate way is reviewed as a separate category. Different protocols, in each group, are compared: concomitant combination of hFSH/hMG (protocol # 1), sequential combination of the two gonadotropins (protocol # 2), and pure FSH administration (protocol # 3). Several parameters were used in the evaluation of the results: 1) day of laparoscopy, 2) volume of the follicles obtained, 3) number of preovulatory oocytes obtained, 4) number of immature oocytes obtained, 5) number of atretic oocytes induced, 6) number of oocytes with abnormal zona pellucida, 7) fertilization rate of preovulatory and immature oocytes, 8) abnormal fertilization rate of preovulatory and immature oocytes, 9) cleavage rate of the normally fertilized preovulatory immature oocytes, 10) transfer rate, single and multiple, 11) follicular and luteal phases as evaluated by estradiol levels in the preovulatory phase and by E2 and progesterone in the post ovulatory phase, 12) pregnancy rate. Pure FSH seems to prolong somewhat the follicular phase. Preovulatory oocytes derived from small follicles may originate pregnancies that may end in abortion. The concomitant combination rendered a larger number of preovulatory oocytes. The number of immature oocytes tend to be higher in the pure FSH stimulated group, but this seems to depend on the way FSH is used. The normal fertilization rate for preovulatory oocytes tends to be similar as the criteria used in the stimulation protocol improved. The abnormal fertilization rate for both types of oocytes decreased in the latest series. The number of embryos transferred was higher in the concomitant combination stimulation. Shortening the hMG/hCG interval in the pure FSH category seems to induce a deficient follicular phase except in cases with rapid high response. When using the hFSH/hMG combination the values of estradiol in the follicular phase tend to be much higher than when the original pure hMG protocol is used. This does not seem to be true when pure FSH stimulation is used. The number of multiple transfers increased substantially in both types of stimulation as experience increased.(ABSTRACT TRUNCATED AT 400 WORDS)

Chorionic Gonadotropin↗
PubMed1985

[Psychology and social ecology of the aged (or the dynamics of gerontologic action)].

Increasingly, gerontologists are recognizing the need to counteract the detrimental effects which prevalent attitudes toward age have on programs for the elderly. A familiar example is the widespread but misguided view that old age is a medical condition best treated as a terminal illness. Challenging such noxious misconceptions, the authors point out that old age--by the same token as infancy, childhood, adolescence, adulthood and mid-life--is a natural phase in human development, with its own strengths and weaknesses, wisdom and shortcomings, joys and sorrows, problems and solutions and, above all, its own rightful place in the natural scheme of things. Remarking that the accumulation of knowledge alone does little or nothing to improve the quality of life, they launch an appeal for redoubled efforts to find practical measures to help the elderly adjust to their particular phase of development. They suggest that such efforts would be greatly facilitated by having the elderly participate actively in the development of their own programs, particularly if their participation encompasses concepts which can infuse meaning into life as a whole.

Aged↗
PubMed1971

The genetics of the photodermatoses.

There are multiple genetic disorders with photosensitivity. The first large group consists of the porphyrias about which a great amount of knowledge has accumulated. The second group is not as well-defined for they are the heredodegenerative disorders of which xeroderma pigmentosum is the most important because here the basic defect in DNA repair is known. Some of the aminoacidurias may cause photosensitivity because of pigment dilution or pellagra-like states. The last group consisting of Darier's, polymorphic light eruption and others are poorly understood, and photosensitivity here is not present in all cases.

Adolescent↗
PubMed1979

The arthroscope in the diagnosis of disorders of the patellofemoral joint.

Despite our current knowledge and accumulated information, orthopedic surgeons often experience difficulties in the diagnosis of internal derangement of the knee. Too often, the admission diagnosis I.D.K. means "I don't know." Disorders of the patellofemoral joint contribute to this difficulty and may simulate torn menisci and loose bodies, as well as the instability which results from rotary displacement. Patients often have difficulty describing and locating their symptoms, and 2 or more pathologic lesions may be present in the same joint. Early lesions involving the articular cartilage are especially difficult to diagnose. Even the most astute clinician cannot rely entirely on his clinical judgement, and, at times, needs the assistance of other diagnostic measures. Arthroscopy is an invaluable aid in the diagnosis of all intra-articular pathology, permitting the proper incision in the proper area, often eliminating the necessity of opening the joint and always avoiding unnecessary meniscectomy.

Adult↗
PubMed1984

Ingestions considered nontoxic.

We have compiled a list of common household products and drugs that are frequently ingested by children and may be considered nontoxic unless taken deliberately or in large amounts. An understanding of the nontoxic ingestion should prevent overtreatment, decrease emergency room visits, and allow physicians and poison control centers the opportunity to practice poison prevention. The reporting of all ingestions is encouraged to obtain information on the human experiment that occurs when a non-edible material is ingested. Only as we accumulate this knowledge will we be able to advise with a degree of certainty what treatment is needed.

Adhesives↗
PubMed1982

The role of bacterial adherence in infection.

The data presented in this review indicate that bacteria have developed mechanisms to facilitate adherence to target mammalian cells, often present in filamentous structures of varying organization at the cell surface, classified together as adhesins. These may contain distinctive molecular sequences, often including sugars, which function as ligands for specific interactions with receptors on mammalian cells. Such receptor-ligand interactions determine species, organ, and cell specificity of adherence by individual bacterial strains. In some examples, this adherence phenomenon can be demonstrated to be an essential virulence attributed of pathogens which must adhere in order to colonize and then cause disease. While considerable detailed knowledge has accumulated about certain adhesins (e.g., K-88) or some mammalian cell receptors (e.g., the pk blood group-related disaccharide on human erythrocytes for pyelonephritis strains of E. coli), in no instance do we know the nature of an adhesin and its specific receptor to fully define the actual chemistry of the binding, but we undoubtedly will in the near future. Avidity of adherence is attributable to multiple forces, in particular hydrophobic interactions in prokaryote-eukaryote systems. Therapeutic strategies to alter these relationships and thereby to prevent or treat disease are already being applied to model in vitro and experimental in vivo infections.

Adhesiveness↗
PubMed1995

Screening strategies: a clinical perspective.

Prostate cancer is increasing in incidence, particularly because of the control of competing causes of death and the lengthening life span of western men. Screening and early detection initiatives among symptom free men show that the disease can be detected at earlier stages when hope for cure is reasonable. Prostate specific antigen is the most useful marker for prostate cancer. Analytical methods to improve its sensitivity and specificity include PSA density, age specific PSA reference ranges and PSA velocity or the rate of change in PSA. Older paradigms of the natural history of prostate cancer have been heavily influenced by characteristics of clinical disease. However, improved detection of the disease through better diagnostic tools and heightened public awareness may be changing the dynamics of the disease. The prevalence of advanced disease is falling, and more knowledge is accumulating on the identification of clinically significant disease. The most appropriate definition of clinically significant disease today must be based on a new paradigm, one that can build on but not be bound by older models.

Adult↗
PubMed1994

Possible role of beta-blockers in the prevention of sudden cardiac death (SCD) in patients with coronary heart disease (CHD).

The prevention of sudden cardiac death remains one of the greatest challenges in the field of cardiovascular medicine today. Despite the difficulty in predicting which individuals are going to die suddenly, much knowledge has accumulated in recent years in regard to independent risk factors for SCD and moreover, different pharmacological interventions have been evaluated for the prevention of sudden coronary death. Currently, the beta-blockers are the only pharmacological agents that have been shown to reduce sudden cardiac deaths in clinical trials. The reduction in sudden death may involve several mechanisms that include antiatherosclerotic effects, antithrombotic effects, cardiac anti-ischemic effects and antifibrillatory effects.

Adrenergic beta-Antagonists↗
PubMed1994

[DNA diagnosis: its induction, problem and future--with special reference to congenital goiter].

PCR technique is a powerful tool for genetic analysis of various diseases including infectious diseases, inherited diseases and malignant tumors. Some of our experiences and problems in gene level diagnosis using mainly the PCR technique newly introduced to our clinical laboratory were discussed. A case of congenital goiter in which the analysis at the gene level was the first demonstration of a mutation associated with the abnormal expression of the thyroglobulin gene in man, is also presented. The direct demonstration from the sputum of the presence of M. tuberculosis DNA by PCR will be a great benefit to the clinician in the diagnosis and treatment of tuberculous infection. At present, it is possible to report the results within 2 days from the submission of samples, but further considerations on the sensitivity and specificity are required. The clinical laboratory will be required to accumulate sufficient knowledge of gene level analysis of various disease conditions and master the techniques.

Adult↗
PubMed1994

Health care during prolonged weightlessness in humans.

The demands for accumulation of knowledge about the human adaptation to weightlessness of long duration and the implications for the health and well-being of the astronaut have become increasingly important also for the international space programmes which are under development. The health care during long duration space-flights starts already with the selection where professional, psychological and medical criteria are considered. Space flights in low earth orbit have not been extended beyond 1 year, so the predictable value for long term space flights is limited, because e.g. Mission to Mars will last from 1.5 to 3 years, depending on the position of the planets, the space vehicle etc. The long duration and the enormous distance covered will induce very special and until now unknown effects on the human psychology which might be seen as the one single major factor which might be prohibitive for such long duration flights. The Moon base will bring further knowledge useful for long duration space flights in the field of medical care in general, but also with regard to the development of countermeasures against the adverse effects of weightlessness on the human body. The Moon's gravitational field of 0.16 G makes it possible to study this as a threshold in the adaptation processes.

Aerospace Medicine↗
PubMed1993

[Dynamics of cognitive abilities in the course of active lifespan].

Behavioral effects of cognitive aging and the meaning of experience are compared. Relating the process of aging to biological and functional decay does not do justice to the accumulation of knowledge and abilities over the active lifespan. Human development is a continuous process of growth and decline. It accounts for both gain and loss of cognitive abilities. From this perspective human capacities are not static but composed of a changing set of abilities which grow and decline over the life span. Despite decreasing capacity with age, reserve capacity may be sufficient to cope with normal task demands. Finally, it is illustrated how experience of older workers may contribute to the design of training programs.

Activities of Daily Living↗
PubMed1995

Biochemical aspects of iron metabolism, transport and regulation.

Iron metabolism in man is controlled by homeostatic mechanisms mainly based on intracellular regulation of iron uptake, utilisation and storage. Despite impressive accumulation of knowledge in recent years, the question how iron actually passes cellular membranes and how this transport process is regulated remains largely unanswered. Various models and hypotheses are discussed in context with other well established features of iron homeostasis.

Anemia, Iron-Deficiency↗
PubMedDate not supplied

Major depression in children and adolescents.

Major depressive disorder (MDD) in young people is relatively common, disabling and recurrent, involving a substantial level of morbidity and mortality, mainly through suicide. Although much remains to be learned, an impressive body of knowledge has accumulated over the previous decade regarding the epidemiology, clinical features, management and outcome of MDD.

Adolescent↗