PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Modifiable factors”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed2004

The contribution of dementia to the disablement process and modifying factors.

The objective of this study was to examine the impact of dementia on disability progression and mortality, and to analyze the modifying effect of risk factors and extra-individual factors. A sample of 3,403 participants in the PAQUID study was followed for 10 years. Disability was assessed on a 4-grade scale: no disability, disabled only on the Rosow-Breslau scale, disabled on the Rosow-Breslau scale and on instrumental activities of daily living (IADL) scales, and disabled on the Rosow-Breslau, IADL and activities of daily living (ADL) scales. A Markov model was used to estimate the effect of explanatory variables on disability and mortality. Controlling for age, gender, education, place of residence, medical care and informal support, dementia had a strong significant effect on progression to IADL and then to ADL disability. Dementia did not increase the risk of death, once disability was taken into account, except from the lowest disability grade.

Aged↗
PubMed1997

[Which factors modify the reproducibility of patient positioning in the daily irradiation routine?].

AIM: Factors which influence the accuracy of the field application during daily irradiation routine are not well known. The aim of this prospective analysis was to determine the significance of these factors on the occurrence of field misadjustments in irradiation without immobilization and to evaluate their clinical relevance. PATIENTS AND METHODS: Fifty-three patients received external cobalt-60 beam irradiation without fixation. Once weekly portal images of all treatment fields were carried out. In addition to objective patient data (age, weight, height, general condition, irradiation indication), the psychological situation of the patient during treatment (anxiety, restlessness, pain) and work circumstances of the medical staff during treatment were evaluated once weekly. The distance of clearly visible anatomic structures to the field borders of the portal images were measured and the deviation to the corresponding simulator images was calculated. Patient data were correlated to the number of field misadjustments (deviation larger than 1 cm). RESULTS: Patients whose condition is generally poor and patients being treated palliatively, patients with feeling of anxiety, restlessness or pain during simulation or irradiation and heavy patients (90 kg and more) were more often misadjusted. The number of field misadjustments increased with the stress of the medical staff. CONCLUSIONS: The problem of reproducibility of external beam irradiation without fixation in palliative treatment is of clinical relevance. Effective analgesic therapy and a comfortable and painfree patient set-up reduce misadjustments. In curative treatment, immobilization techniques should be used.

Aged↗
PubMed1993

Atrial natriuretic factor modifies bile flow and composition in the rat.

The effects of atrial natriuretic factor (ANF) on bile secretion were studied in the rat. ANF was injected 'in bolus' (5.0 micrograms/kg) every 30 min into the jugular vein. The common bile duct was cannulated and bile samples were collected every 30 min for 120 min. Systemic blood arterial pressure was registered before and after the administration of ANF. Results showed that ANF decreased bile flow and the excretion rate of sodium, potassium, chloride, bile acids, cholesterol and proteins. On the other hand, it increased pH and the excretion of bicarbonate and calcium. As ANF slightly reduces mean arterial pressure, its vascular effect may not be considered the major event. In addition, increased excretion of bicarbonate and calcium, and the fact that ANF vascular effect is short in time suggest that the peptide may have a non-vascular effect on the processes of bile formation and its modifications along the bile ducts. This extravascular effect may be exerted on the hepatocyte ions exchangers and/or at the ductal level on the processes of excretion and reabsorption of electrolytes and water.

Animals↗
PubMed2001

Factors modifying the migration of lymphocytes across the blood-brain barrier.

Characterising the factors that control the entry of leucocytes into tissue in response to inflammatory or microbial insult continues to generate considerable interest. Of all the tissues studied it is probably that of the CNS which is the most fascinating because of the specialised properties of its blood vessel walls, which constitute the blood-brain barrier (BBB). In health, very few leucocytes penetrate the BBB but in disorders such as MS the barrier becomes compromised with the result that there is an intense infiltration of the CNS by T lymphocytes whose subsequent activity appears to underlie the onset and progression of disease. The purpose of this article is to summarise and assess recent literature pertaining to how lymphocytes bind to cerebral endothelial cells, migrate across the blood vessel walls and enter the CNS parenchyma. Particular emphasis is devoted to the cellular and molecular aspects of these events and addressing the questions of whether certain subsets of circulating T lymphocytes are more favourably disposed than others to CNS infiltration and whether entry is dependent upon the initial expression of distinct groups of adhesion molecules and upon the generation of chemotactic factors. This article also focuses upon identifying the key stages of lymphocyte migration across the BBB and their susceptibility to antagonism by therapeutic agents. It is intended that the review will provide a useful source of information and offer additional insights into the mechanisms controlling lymphocyte passage across the BBB during pathological disturbance.

Animals↗
PubMed1976

Analogues of luteinizing hormone releasing factor modified at positions 2, 6, and 10.

Eighteen analogues of luteinizing hormone releasing factor (LRF, pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2) were synthesized. The ten agonistic analogues were [D-Lys6], [D-Orn6], [D-Lys6,des-Gly10,Pro9-NHEt], [D-Orn6,-des-Gly10,Pro9-NHEt]-LRF plus their respective lauric acid conjugates as well as [(Nepsilon-Ac)-D-Lys6] and [(Ndelta-Ac)-D-Orn6]-LRF. The eight antagonistic analogues were [des-His2,D-Lys6], [des-His2,D-Orn6], [des-His2,D-Lys6,des-Gly10,Pro9-NHEt], [des-His2,D-Orn6,des-Gly10,Pro9-NHEt]-LRF as well as their respective lauric acid conjugates. Biological activities of these analogues were determined in vitro, using LRF as the standard for the agonists and [des-His2,D-Ala6]-LRF for the antagonists. The potency of the agonists ranged from 1 to 17 times the activity of LRF while the antagonists had between 1 and 3 times the potency of [des-His2,D-Ala6]-LRF.

Animals↗
PubMed1988

[Climatic factors modifying the performance of cattle in Nigeria].

Continuing previous analogous investigations on climatic factors limiting the performance of cattle, temperature and humidity values were determined in southern Nigeria and were related to the established physiological compatibility conditions for cattle. A good agreement was found between the values determined in 1984 and 1985. On average (for both years) the outside temperatures surpassed the physiologically-compatible limit of 24 degrees C to the extent of 57.8%. Not more than 1.3% of the total hours were within the optimum temperature range for cattle. The values for the relative humidity were within the optimum cattle range by 27.4% in the two-year average, whereas they were too moist by 35.1%.

Animals↗
PubMed1983

Production by various Pseudomonas species of a factor modifying the enterobacterial common antigen.

The enterobacterial common antigen (ECA) is a common determinant shared by almost all members of the family Enterobacteriaceae. The antigen modifies erythrocytes for agglutination by ECA antibodies. Previously it was reported that Pseudomonas aeruginosa produces a factor (PF) which destroys the erythrocyte-modifying capacity of ECA. The present investigation was undertaken to determine whether other species of this genus also produce PF. The passive bacterial hemagglutination and hemagglutination inhibition tests were used. It was observed that 47 strains belonging to 8 species of the genus Pseudomonas produce this factor and 34 strains representing 12 other species do not. Multiple strains of a given species gave concordant results. Mucoid variants of P. aeruginosa produced more of this factor than did nonmucoid isolates recovered from the identical sputum specimens from patients with cystic fibrosis. ECA treated with PF no longer modifies erythrocytes for agglutination by ECA antibodies and exerts less antibody-neutralizing capacity than untreated antigen.

Antigens, Bacterial↗
PubMed1994

Atrial natriuretic factor modifies noradrenaline release in a sodium-free medium.

1. The effects of atrial natriuretic factor (ANF) on 3H-noradrenaline (3H-NA) release evoked by a sodium-free medium (SFM) were studied. The experiments were carried out in rat hypothalamic slices incubated in vitro. 2. ANF (1, 10 and 100 nM) decreased NA release evoked by the omission of sodium in a concentration-dependent way. When calcium was omitted from a SFM, NA output was partially diminished. However, if ANF was added to the SFM/calcium free medium NA secretion showed no modifications. 3. Present results suggest that, in rat hypothalamus, NA release evoked by Na+ omission is divided into two fractions: one independent of and the other dependent on extracellular calcium. In addition, ANF modifies NA release evoked by SFM dependent on extracellular calcium.

Animals↗
PubMed1988

Factors modifying the effect of diazepam on plasma corticosterone levels in rats.

We have examined factors that alter the effect of diazepam (DZ) on plasma corticosterone (CS) in rats. DZ had a biphasic effect on plasma CS levels: CS decreased with doses below 5 mg/kg and increased with higher doses. Peak response occurred 90 minutes post injection in both sexes. Plasma DZ levels were significantly higher in females than in males and peak at 10 and 30 minutes post injection in males and females, respectively. There was also a sex difference in the pattern of DZ metabolites. An acute stressor (30 minutes of immobilization) did not affect plasma CS levels in rats injected with a 5 mg/kg dose of DZ. Prenatally stressed animals did not differ in basal CS levels or in their response to 5 mg/kg of DZ compared to prenatally non-stressed animals. These two groups of animals also did not differ in plasma levels of DZ or of its metabolites. By contrast, the 5 mg/kg dose of DZ had no effect on plasma testosterone levels in control animals, but increased it in prenatally stressed animals. Furthermore, compared to non-stressed controls, prenatally stressed animals had lower baseline plasma testosterone levels. These results indicate that the effect of DZ on plasma CS is influenced by endogenous as well as exogenous factors and that these effects vary with the particular biochemical parameter under examination.

Animals↗
PubMed2003

[Factors modifying noise-induced hearing loss].

This paper introduces the current data on the factors, which determine individual susceptibility to noise. Pathophysiology of occupational noise-induced hearing loss is nowadays a well-known issue. Both experimental and clinical data presented, show the variety of factors influencing the natural history of hearing impairment in workers employed in various branches of industry. It is necessary for an occupational medicine specialist to consider these factors in preventing hearing impairment as noise, according to epidemiological data, is the most common harmful factor in the work environment.

Age Factors↗
PubMed1994

Epidermal growth factor modifies cell cycle control in A431 human squamous carcinoma cells damaged by ionizing radiation.

Epidermal growth factor (EGF) has been shown to radiosensitize A431 and other human squamous carcinoma cells with high numbers of surface EGF receptors. In this study of the mechanistic basis of EGF-induced radiosensitization, both EGF and ionizing radiation caused G1 phase arrests in cycling A431 cells, but only radiation caused a G2-M arrest. However, EGF enhanced the magnitude of this G2-M arrest, suggesting an interaction of signaling pathways involved in cellular responses to EGF and radiation damage. EGF and radiation also uniquely perturbed cyclin A and B1 mRNA levels during the time of maximum radiation-induced G2-M arrest. The effects of EGF on G2-M events probably originated in cells in G1. It is possible that aberrant EGF signal transduction in human squamous carcinoma cells may be exploited as a novel strategy for radiotherapy.

Carcinoma, Squamous Cell↗
PubMed1993

Oral contraceptives and endometrial cancer: do other risk factors modify the association?

The joint effect of use of combination-type oral contraceptives and other exposure factors on risk of endometrial cancer was examined in data from a multicenter case-control study conducted in 5 areas of the United States. Cases were 405 women with histologically confirmed invasive epithelial endometrial cancer first treated at one of 7 participating hospitals. A total of 297 population-based controls of similar age, race, and geographic area were selected as a comparison group. Information on exposure factors was derived from in-person interviews. Combination-type oral contraceptive (COC) use was associated with a significant reduction in risk of endometrial cancer, with an adjusted odds ratio (OR) of 0.4 (95% confidence interval 0.3 to 0.7) for ever compared to never use. Long-term (> or = 10 years) users experienced a markedly lower risk (OR = 0.2). Women who discontinued COC use > or = 20 years earlier remained at reduced risk (OR = 0.7) compared with non-users. The negative association with COC use was apparent regardless of the presence or level of several other risk factors for endometrial cancer, including age, menopausal status, parity, obesity, ever-use of menopausal estrogens, smoking history, or history of infertility. The magnitude of the negative association observed in COC users, however, was considerably diminished in women with no full-term births and in women who subsequently used replacement estrogens for 3 or more years. These results provide new evidence that the protective effect of COC use lasts for 20 or more years after use is discontinued, and highlight several sub-groups of users in whom the level of protection is attenuated by the presence of other risk factors for this disease.

Adult↗
PubMed1999

Nerve growth factor modifies the expression of inflammatory cytokines by mast cells via a prostanoid-dependent mechanism.

Nerve growth factor (NGF) is well recognized to have a number of potent effects on mast cells, including increasing mast cell numbers in vivo and inducing mast cell degranulation in vitro. More recently, NGF has been demonstrated to induce PGD2 production by mast cells through the induction of mast cell cyclooxygenase expression. We have observed that NGF at doses as low as 10 ng/ml will induce IL-6 production and inhibit TNF-alpha release from rat peritoneal mast cells in the presence of lysophosphatidylserine as a cofactor. NGF synergizes with LPS treatment of peritoneal mast cells (PMC) for the induction of IL-6. Examination of the mechanism of this phenomenon has revealed that NGF can induce both rat PMC and mouse bone marrow-derived cultured mast cells to produce substantial levels of PGE2. This response is maximal at later time points 18-24 h after NGF activation. The ability of NGF to induce PGE2 is not dependent on mast cell degranulation. Other stimuli capable of inducing IL-6, such as LPS, do not induce production of this prostanoid. Inhibition of cyclooxygenase activity by PMC using either flurbiprofen or indomethacin inhibited both the NGF-induced PGE2 synthesis and the NGF-induced alterations in TNF-alpha and IL-6 production. These results suggest a role for mast cell-derived prostanoids in the regulation of local inflammatory responses and neuronal degeneration after tissue injury involving induction of NGF production.

Animals↗
PubMed1997

Atrial natriuretic factor modifies the biosynthesis and turnover of norepinephrine in the rat adrenal medulla.

In the present work we investigate atrial natriuretic factor (ANF) effects on the endogenous content, utilization and turn over of norepinephrine (NE), on tyrosine hydroxilase (TH) activity, on cAMP and cGMP levels, and on phosphatidylinositol hydrolysis in rat adrenal medulla in order to assess the possible mechanisms underlying ANF effects on NE metabolism. Results showed that ANF (5 microg/kg) increased NE endogenous content (44%) and diminished the amine utilization. On the other hand, the atrial factor (10 nM) inhibited both spontaneous and evoked, by 100 mM KCl TH, activity (48% and 59%, respectively). When second messenger systems were studied results showed that 10 nM ANF increased cGMP levels in adrenal medulla (51%), while it modified neither cAMP levels nor phosphatidylinositol hydrolysis. These results suggest that ANF may play an important role in the modulation of the sympathoadrenergic system function, behaving as a putative neuromodulator.

Adrenal Medulla↗
PubMed1996

Atrial natriuretic factor modifies the composition of induced-salivary secretion in the rat.

We have previously reported that although the atrial natriuretic factor (ANF) was not a sialogogic agonist, it enhanced cholinergic, alpha-adrenergic and peptidergic (substance P) stimulated salivation in the submaxillary and parotid gland of the rat. The purpose of the present work was to study whether ANF modified the composition of agonist-induced saliva in the rat. Results showed that in the submaxillary gland, ANF increased sodium and decreased potassium excretion when salivation was stimulated by methacholine (MC) or substance P (SP). However, when salivation was induced by methoxamine (MX), ANF only increased sodium excretion. On the other hand, in the parotid gland, ANF increased both sodium and potassium excretion when salivation was induced either by MC or SP but did not modify electrolyte output in MX induced salivary secretion. Protein output and amylase activity were not modified by the presence of ANF when the aforementioned sialogogic agonists were used to elicit salivation in either gland. Although ANF did not modify the volume of isoproterenol (IP) induced saliva, it increased protein output in both glands and it increased amylase activity in the parotid gland. The present results suggest that ANF may play a role in the modulation of salivary secretion in the parotid and submaxillary glands of the rat. ANF effect is likely to be mediated by modifications in the calcium level linked to phosphoinositide metabolism within the acinar and/or the ductal cells of the salivary glands.

Animals↗
PubMed1997

[Do psychological factors modify survival of cancer patients? I: Review of the literature].

The present paper addresses the question whether psychological factors influence the course of the disease in cancer patients. Studies investigating this issue are reviewed from a methodological point of view. The main objective is to design guidelines for future research. The review begins with Greer's and his co-workers' study on breast cancer patients. They demonstrated that ways of coping called fighting spirit and denial are predictive of longer survival. However, axillary lymph node status and oestrogen receptor status could not be controlled, because these measures had not been assessed on a routine basis at the time of diagnosis. The Greer study has been stimulating a series of replications. Moreover, investigations into patients with various other cancer sites including melanoma and lung cancer have been performed. In general, results were inconsistent. Studies with positive findings are contrasted by those with negative results. Within positive findings, results were partially contradictory. Moreover, most of the investigations suffered from serious methodological limitations rendering interpretation difficult. The following methodological conclusions can be drawn: Testing of a priori hypotheses instead of multiple retrospective tests; prospective design to prevent that psychological predictors turn out to be indicators of the somatic state of the patient; multi-method and longitudinal assessment of coping and adaptation; homogeneous sample; taking into account all known biological prognostic factors; multivariate statistical analysis.

Adaptation, Psychological↗
PubMed1995

Further application and evaluation of critical cell number and modifying factors in radiocurability of multicellular spheroids.

Relationship of cure and surviving clonogenic cell number after various doses of X-irradiation was examined in multicellular spheroids of LCT1 human lung adenocarcinoma cells, LCT2 human lung small cell carcinoma cells and FSA1233 mouse fibrosarcoma cells. Some of these spheroids were cured at such doses that considerable number of clonogenic cells still survived after irradiation. Radiocurability was analyzed by comparing total clonogenic cell number in spheroids, cellular radiosensitivity and critical cell number Nc, i.e., the minimum number of clonogenic cells required to produce regrowth. (Nc-1) cells were killed by post-radiation processes and the larger the critical cell number, the more radiocurable. The LCT2 spheroids had the largest critical cell number and were most radiocurable. To investigate underlying mechanisms, modifying effect of heavily irradiated (HIR) tumor cells on the clonogenicity, i.e., plating efficiency of unirradiated tumor cells was investigated. Plating efficiencies with HIR cells showed significant decrease in LCT2 cells, no change in LCT1 cells and increase in FSA1233 cells. The results indicated that in case of LCT2 spheroids some of viable cells surrounded by dying or dead cells might have been killed with unknown toxic effect additional to direct irradiation effect. Thus, critical cell number analysis may be useful to quantify and to compare modifying effect of cellular/environmental factors in curing process of spheroids or tumors.

Adenocarcinoma↗