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1.
Int J Child Maltreat ; 6(1): 119-130, 2023.
Article in English | MEDLINE | ID: mdl-36405490

ABSTRACT

Child maltreatment has detrimental social and health effects for individuals, families and communities. The ERICA project is a pan-European training programme that equips non-specialist threshold practitioners with knowledge and skills to prevent and detect child maltreatment. This paper describes and presents the findings of a rapid review of good practice examples across seven participating countries including local services, programmes and risk assessment tools used in the detection and prevention of child maltreatment in the family. Learning was applied to the development of the generic training project. A template for mapping the good practice examples was collaboratively developed by the seven participating partner countries. A descriptive data analysis was undertaken organised by an a priori analysis framework. Examples were organised into three areas: programmes tackling child abuse and neglect, local practices in assessment and referral, risk assessment tools. Key findings were identified using a thematic approach. Seventy-two good practice examples were identified and categorised according to area, subcategory and number. A typology was developed as follows: legislative frameworks, child health promotion programmes, national guidance on child maltreatment, local practice guidance, risk assessment tools, local support services, early intervention programmes, telephone or internet-based support services, COVID-19 related good practices. Improved integration of guidance into practice and professional training in child development were highlighted as overarching needs. The impact of COVID-19 on safeguarding issues was apparent. The ERICA training programme formally responded to the learning identified in this international good practice review.

3.
Dent Mater ; 37(7): 1134-1149, 2021 07.
Article in English | MEDLINE | ID: mdl-33858665

ABSTRACT

OBJECTIVE: To investigate the intraoral development and kinetics of low-temperature degradation (LTD) in second-generation 3 mol.% yttria-doped tetragonal zirconia polycrystal (3Y-TZP) monolithic prostheses, as well as the influence of masticatory mechanical stress and glaze layer on it. METHODS: A total of 101 posterior tooth elements were included in a prospective clinical study, which included ex vivo LTD monitoring (at baseline, 6 months, 1 year, and 2 years) using Raman spectroscopy (n = 2640 monoclinic phase measurement points per evaluation time) and SEM. Four types of areas (1-2 mm2 surface, 6 on molars, and 4 on premolars) were analyzed on each element surface: occlusal, axial, glazed, or unglazed. Raman depth mapping and high-resolution SEM were performed on the selected samples. RESULTS: LTD developed in 3Y-TZP monolithic restorations 6 months after intraoral placement and progressed with time. After two years, the tetragonal-to-monoclinic transformation was non-uniform, with the presence of localized clusters of transformed grains. In axial areas, the grain aspect was typical of the classical nucleation-growth process reported for LTD, which progresses from the surface to a depth of several tens of microns. However, in occlusal areas, tribological stress generated surface crushing and grain pull-out from the clusters, which induced an underestimation of the aging process when the evaluation was limited to monoclinic phase quantification. Glazing cannot be considered a protection against LTD. SIGNIFICANCE: If LTD occurs in dental prostheses in the same way as in orthopedic prostheses, its clinical impact is unknown and needs to be further studied.


Subject(s)
Dental Prosthesis , Zirconium , Ceramics , Dental Materials , Materials Testing , Prospective Studies , Surface Properties , Temperature , Yttrium
4.
Respir Res ; 22(1): 61, 2021 Feb 19.
Article in English | MEDLINE | ID: mdl-33608009

ABSTRACT

BACKGROUND: Mechanisms that preclude lung metastasis are still barely understood. The possible consequences of allergic airways inflammation on cancer dissemination were studied in a mouse model of breast cancer. METHODS: Balb/c mice were immunized and daily exposed to ovalbumin (OVA) from day 21. They were subcutaneously injected with 4T1 mammary tumor cells on day 45 and sacrificed on day 67. Lung metastases were measured by biophotonic imaging (IVIS® 200 Imaging System) and histological measurement of tumor area (Cytomine software). Effects of CCL11 were assessed in vivo by intratracheal instillations of recCCL11 and in vitro using Boyden chambers. CCR3 expression on cell surface was assessed by flow cytometry. RESULTS: The extent of tumor metastases was significantly higher in lungs of OVA-exposed mice and increased levels of CCL11 expression were measured after OVA exposure. Migration of 4T1 cells and neutrophils was stimulated in vitro and in vivo by recCCL11. 4T1 cells and neutrophils express CCR3 as shown by flow cytometry and a selective CCR3 antagonist (SB-297006) inhibited the induction of 4T1 cells migration and proliferation in response to recCCL11. CONCLUSIONS: Allergic inflammation generated by exposure to allergens triggers the implantation of metastatic cells from primary breast tumor into lung tissues plausibly in a CCL11-CCR3-dependent manner. This indicates that asthma related inflammation in lungs might be a risk factor for lung metastasis in breast cancer patients.


Subject(s)
Asthma/complications , Breast Neoplasms/pathology , Chemokine CCL11/metabolism , Inflammation/etiology , Lung Neoplasms/secondary , Neoplasms, Experimental , Receptors, CCR3/metabolism , Animals , Asthma/metabolism , Cells, Cultured , Female , Inflammation/metabolism , Inflammation/pathology , Lung/metabolism , Lung/pathology , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Male , Mice , Mice, Inbred BALB C , Tumor Cells, Cultured
5.
J Dent ; 92: 103245, 2020 01.
Article in English | MEDLINE | ID: mdl-31747585

ABSTRACT

OBJECTIVES: To prospectively evaluate the One-step No-prep treatment of full mouth-worn dentition, a minimally invasive and multidisciplinary approach using PICN CAD-CAM composite restorations without provisional phase. METHODS: Seven patients (n = 192 restorations) with severe tooth wear were included. Patient data were recorded, and an occlusal analysis and a tissue-guided wax-up were realized. After replacement of old fillings, no-prep Vita Enamic restorations (posterior restorations and palatal veneers) were bonded within 24 h. Direct composites were performed to mask the buccal joint on anterior teeth. Maxillo-facial physiotherapy was performed. Restorations were evaluated following World Dental Federation criteria. Treatment influence on Oral-Health-Impact-Profile-49 (OHIP-49) score was assessed. RESULTS: Tooth wear etiology was related to soft drink consumption and bruxism. Mean VDO increase was 5.09 ±â€¯0.85 mm on the incisal pin. The mean restoration thickness on molars was 0.55 ±â€¯0.21 mm, and the lowest was 0.11 mm. 2-year survival rate of restorations was 100 % and success rate was 93.5 %, with 11 minor chippings and one debonding. A significant improvement of the global OHIP-49 score was observed. CONCLUSIONS: In this clinical study on high risk patients, PICN restorations, applied in a minimally invasive way, showed high survival and success rates after two years, while minor chipping of very thin occlusal borders constituted the most frequent complication. Moreover, the patient acceptance was good according to OHIP-49 in this multidisciplinary approach. CLINICAL SIGNIFICANCE: The use of PICNs allows the development of no prep and simple treatment protocols of worn dentition. The absence of provisionals did not engender any problem, on the basis of the realization of an occlusal analysis, the support of a maxillo-facial physiotherapist, and the use of an easy-to-adjust restorative material.


Subject(s)
Dentition , Mouth Rehabilitation , Computer-Aided Design , Dental Materials , Dental Restoration, Permanent , Humans , Prospective Studies
6.
J Dent ; 91: 103229, 2019 12.
Article in English | MEDLINE | ID: mdl-31722238

ABSTRACT

OBJECTIVES: This study aimed to investigate (1) clinical outcomes of second-generation zirconia restorations, including patients with bruxism clinical signs, and (2) the material wear process. METHODS: A total of 95 posterior monolithic zirconia tooth-elements in 45 patients were evaluated, 85 on implants and 10 on natural teeth, and 20.3% of restorations being fixed partial dentures (FPDs). Occlusal contact point areas were determined and half of those areas were left unglazed and just polished. Restorations were clinically evaluated following criteria of the World Dental Federation and antagonistic teeth were examined at each evaluation time. Wear ex vivo analyses using SEM and 3D laser profilometry were performed at baseline and after 6 months, 1 year, and 2 years respectively, temporarily removing the prostheses. RESULTS: The Kaplan-Meier survival rate of restorations was 93.3% (100% for FPDs) and the success rate was 81.8%, with 4 abutment debondings, 3 tooth-supported crown debondings (provisional cement use), 1 restoration fracture, 1 minor chipping, 1 core fracture, 1 root fracture, and 2 implant losses. 80% of catastrophic failures occurred in patients with clinical signs of bruxism (61.7% of patients). Complications were also observed on antagonistic teeth (3 catastrophic failures). Clinical evaluation of the restorations showed good results from the aesthetic, functional, and biological perspective. Zirconia wear was inferior to 15 µm, while glaze wear was observed on all occlusal contact areas after 1 year. CONCLUSIONS: Monolithic zirconia FPDs are promising but the failure rate of single-unit restorations was not as high as expected in this sample including patients with bruxism clinical signs. CLINICAL SIGNIFICANCE: Within study limitations, FPDs showed excellent short-term results but further research is needed for single-unit restorations considering samples, which do not exclude bruxers. The weak link is the restoration support or the antagonist tooth, one hypothesis being that zirconia stiffness and lack of resilience do not promote occlusal stress damping.


Subject(s)
Bruxism , Crowns , Dental Prosthesis, Implant-Supported , Dental Restoration, Permanent , Denture, Partial, Fixed , Zirconium , Dental Restoration Failure , Humans , Prospective Studies
7.
Mucosal Immunol ; 7(3): 568-78, 2014 May.
Article in English | MEDLINE | ID: mdl-24172846

ABSTRACT

Chronic obstructive pulmonary disease (COPD) is a major clinical challenge mostly due to cigarette smoke (CS) exposure. Invariant natural killer T (iNKT) cells are potent immunoregulatory cells that have a crucial role in inflammation. In the current study, we investigate the role of iNKT cells in COPD pathogenesis. The frequency of activated NKT cells was found to be increased in peripheral blood of COPD patients relative to controls. In mice chronically exposed to CS, activated iNKT cells accumulated in the lungs and strongly contributed to the pathogenesis. The detrimental role of iNKT cells was confirmed in an acute model of oxidative stress, an effect that depended on interleukin (IL)-17. CS extracts directly activated mouse and human dendritic cells (DC) and airway epithelial cells (AECs) to trigger interferonγ and/or IL-17 production by iNKT cells, an effect ablated by the anti-oxidant N-acetylcystein. In mice, this treatment abrogates iNKT-cell accumulation in the lung and abolished the development of COPD. Together, activation of iNKT cells by oxidative stress in DC and AECs participates in the development of experimental COPD, a finding that might be exploited at a therapeutic level.


Subject(s)
Lymphocyte Activation/immunology , Natural Killer T-Cells/immunology , Natural Killer T-Cells/metabolism , Oxidative Stress/immunology , Pulmonary Disease, Chronic Obstructive/immunology , Pulmonary Disease, Chronic Obstructive/metabolism , Animals , Antigen-Presenting Cells/immunology , Antigen-Presenting Cells/metabolism , Antioxidants/pharmacology , Benzene Derivatives/pharmacology , Dendritic Cells/immunology , Disease Models, Animal , Humans , Lung/drug effects , Lung/immunology , Lung/metabolism , Lung/pathology , Lymphocyte Activation/drug effects , Lymphocyte Count , Mice , Mice, Knockout , Natural Killer T-Cells/drug effects , Pulmonary Disease, Chronic Obstructive/physiopathology , Tobacco Smoke Pollution
8.
Br J Cancer ; 107(7): 1083-92, 2012 Sep 25.
Article in English | MEDLINE | ID: mdl-22929882

ABSTRACT

BACKGROUND: Overall clinical outcome for advanced lung cancer remains very disappointing despite recent advances in treatment. Curcumin has been reported as potentially active against cancer. METHODS: Owing to poor curcumin solubility, we have used cyclodextrins (CD) as an excipient allowing a considerable increase of aqueous solubility and bioavailability of curcumin. The effects of solubilised curcumin have been evaluated in cell cultures as well as in an in vivo orthotopic lung tumour mouse model. RESULTS: Cell proliferation was reduced while apoptosis rates were increased when lung epithelial tumour cells were cultured in the presence of curcumin-CD complexes. For in vivo experiments, cells were grafted into lungs of C57Bl/6 mice treated by an oral administration of a non-soluble form of curcumin, CDs alone or curcumin-CD complexes, combined or not with gemcitabine. The size of orthotopically implanted lung tumours was reduced upon curcumin complex administration as compared with treatments with placebo or non-solubilised curcumin. Moreover, curcumin potentiated the gemcitabine-mediated antitumour effects. CONCLUSION: Our data demonstrate that curcumin, when given orally in a CD-solubilised form, reduces lung tumour size in vivo. In vitro experiments show impaired tumour cell proliferation and increased cell apoptosis. Moreover, our data underline a potential additive effect of curcumin with gemcitabine thus providing an efficient therapeutic option for antilung cancer therapy.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Lung Neoplasms/drug therapy , Animals , Apoptosis/drug effects , Cell Proliferation/drug effects , Curcumin/administration & dosage , Curcumin/chemistry , Cyclodextrins/administration & dosage , Cyclodextrins/chemistry , Deoxycytidine/administration & dosage , Deoxycytidine/analogs & derivatives , Drug Synergism , G2 Phase/drug effects , Lung Neoplasms/pathology , Male , Mice , Mice, Inbred C57BL , Tumor Cells, Cultured , Gemcitabine
9.
Int J Androl ; 34(6 Pt 2): e587-93, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21696397

ABSTRACT

In healthy middle-aged men, endogenous testosterone does not seem to increase risk for cardiovascular disease (CVD). One explanation might be a differential effect of testosterone, and another, interference with oestradiol with respect to specific cardiovascular functions. To investigate these possibilities, we evaluated in a cross-sectional population of 1223 healthy men, aged 46 (6) years, associations between endogenous testosterone, oestradiol and left ventricular structure and function (echocardiography). Testosterone was inversely associated with ejection fraction (EF) and with more sensitive systolic tissue Doppler imaging indices. Oestradiol was positively associated with EF. These associations were confirmed by linear regression analyses, and consistent for calculated free as well as for total sex steroid concentrations. Standardized regression coefficients were -0.13 for testosterone (P < 0.01) and 0.12 for oestradiol (P < 0.01) for the association with EF, in a model which included height, waist circumference, triglycerides, glucose, systolic blood pressure, drug-treated hypertension, heart rate, haematocrit, current smoking, serum sampling time, age and excessive alcohol use. The study suggests an opposite link, albeit modestly, of testosterone and oestradiol with left ventricle systolic function in healthy middle-aged men. The finding provides a partial explanation for the overall neutral effect on CVD of testosterone in healthy middle-aged men.


Subject(s)
Estradiol/physiology , Testosterone/physiology , Ventricular Remodeling/physiology , Adult , Cross-Sectional Studies , Humans , Male , Middle Aged
10.
J Pathol ; 217(1): 14-20, 2009 Jan.
Article in English | MEDLINE | ID: mdl-18991331

ABSTRACT

Several studies described a role for the E2F/Rb pathway in ovarian serous carcinomas (SCAs). Since E2F/Rb pathway deregulation is a general hallmark of human cancer, it remains unclear whether this deregulation is of particular importance in SCAs or whether it reflects a common oncological feature. Here, we have clarified this issue by the examination of microarray expression profiles of SCAs and particularly by the comparison with another, less malignant, ovarian cancer type, serous borderline tumours (SBTs). Results were validated by quantitative RT-PCR, both on the microarray samples and on an independent panel, and TP53 mutation analysis was performed. This integrated analysis revealed a significant increase in the expression of the transcription factors E2F1 and E2F3 in SCAs, when compared to SBTs. This was associated with vast overexpression of E2F target genes in SCAs compared to SBTs. High-grade SCAs in particular exhibited a major deregulated E2F target expression pattern. Generally, overexpression of E2F targets in SCAs appeared to be well structured since those targets considered negative regulators of the cell cycle or promoters of apoptosis were usually not overexpressed in SCAs. Similar to E2F target deregulation, TP53 mutations were identified in SCA3s, to a lesser extent in SCA1s, and not in SBTs. These results suggest that a structured, generally up-regulated E2F transcription factor activity is associated with a global cell-cycle disturbance in high-grade SCAs and exceeds typical E2F/Rb pathway disruption in tumours, at least compared with SBTs.


Subject(s)
Cystadenocarcinoma, Serous/genetics , E2F1 Transcription Factor/genetics , Neoplasm Proteins/genetics , Ovarian Neoplasms/genetics , Cell Cycle , Cystadenocarcinoma, Serous/metabolism , Cystadenocarcinoma, Serous/pathology , Disease Progression , E2F1 Transcription Factor/physiology , Female , Gene Expression Profiling/methods , Genes, p53 , Humans , Mutation , Neoplasm Proteins/physiology , Oligonucleotide Array Sequence Analysis/methods , Ovarian Neoplasms/metabolism , Ovarian Neoplasms/pathology , Reverse Transcriptase Polymerase Chain Reaction/methods , Signal Transduction , Up-Regulation
12.
J Pathol ; 214(5): 555-63, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18278785

ABSTRACT

Giant cell tumour of bone (GCTB) is a benign bone tumour known for the unpredictable clinical behaviour of recurrences and, in rare instances, distant metastases. It consists of uniformly distributed osteoclastic giant cells in a background of mononuclear rounded and spindle-shaped cells. Cytogenetically, telomeric associations are the most common chromosomal aberrations, which, however, are normally almost exclusively found in high-grade malignancies. GCTB has often been regarded as a polyclonal tumour, but more recently a recurrent specific aberration was reported, which suggests a possible role for disturbed telomere maintenance. Here we further investigate telomere maintenance in GCTB using 19 samples from 19 patients. A combination of immunofluorescence and FISH was performed, applying antibodies directed against promyelocytic leukaemia body-related antigen and hTERT and using telomere peptide nucleic acid probes. The TRAP assay and telomere restriction fragment length analysis were performed for functional detection of telomerase activity and alternative telomere lengthening. Both osteoclastic giant cells and mononuclear cells showed positivity for hTERT and promyelocytic leukaemia body-related antigen. In most mononuclear cells, co-expression was present. The TRAP assay demonstrated heterogeneous telomerase activity, while telomere restriction fragment length analysis showed non-heterogeneous telomere lengths, indicating the absence of alternative telomere lengthening. Confocal microscopy showed stereometric co-localization of nucleolin with promyelocytic leukaemia body-related antigen in association with telomeres in the spindle-shaped cells. hTERT was more diffusely distributed throughout the nucleus. Our results show that GCTB demonstrates remarkable telomere maintenance of activated telomerase and inactivated alternative telomere lengthening in the presence of normal mean telomere restriction fragment lengths. These findings strongly suggest that these aggregates, while activating telomerase, are part of a structural telomere protective-capping mechanism rather than of a telomere-lengthening mechanism. Telomere maintenance could be considered an important key factor in the pathogenesis of GCTB.


Subject(s)
Bone Neoplasms/genetics , Giant Cell Tumors/genetics , Telomere/genetics , Adolescent , Adult , Bone Neoplasms/metabolism , Bone Neoplasms/pathology , Female , Giant Cell Tumors/metabolism , Giant Cell Tumors/pathology , Humans , In Situ Hybridization, Fluorescence , Male , Microscopy, Confocal , Middle Aged , Neoplasm Proteins/metabolism , Nuclear Proteins/metabolism , Osteoclasts/metabolism , Osteoclasts/pathology , Phosphoproteins/metabolism , Promyelocytic Leukemia Protein , RNA-Binding Proteins/metabolism , Telomerase/metabolism , Telomere/ultrastructure , Transcription Factors/metabolism , Tumor Suppressor Proteins/metabolism , Nucleolin
13.
Oncol Rep ; 18(6): 1571-6, 2007 Dec.
Article in English | MEDLINE | ID: mdl-17982646

ABSTRACT

Human linear chromosomes are capped by specialized DNA-protein structures called telomeres. The present study analysed the telomerase activity, hTERT protein and telomere length in meningiomas and gliomas in relation to their WHO grading. Fifty-three freshly dissected tumour biopsies were analysed for telomerase activity, hTERT protein expression and telomere length. Telomerase activity was examined in 41 of the 53 biopsies. Telomerase activity was detected in 3 of 35 (8.6%) screened meningiomas (1 benign, 1 atypical and 1 malignant meningioma). For hTERT expression, 56.4% of meningiomas were positive with a mean labelling index (hTERT LI) of 31.3% (SD=26.5) for the hTERT positive meningiomas. The mean telomere length for meningiomas was 6.983 kb (SD=1.969). For gliomas, no active telomerase was detected in 2 low-grade astrocytomas, whereas three of the four screened glioblastomas were positive for telomerase activity. The only hTERT protein positive astrocytoma had a mean labelling index of 9.0%. On the other hand, the hTERT LI for glioblastomas was 53.6% (SD=28.0). The two low-grade astrocytomas had a telomere length of 14.310 and 9.236 kb. The anaplastic astrocytoma had a telomere length of 4.903 kb and the glioblastomas 5.767 kb (SD=2.042). The normal meningeal and neuronal tissue is negative for telomerase activity and hTERT. The length was +/-10.000 kb. These results indicate that telomere shortening may be a critical step in pathogenesis of atypical and malignant meningiomas and gliomas. Critical telomere shortening in vitro was shown to activate telomerase.


Subject(s)
Brain Neoplasms/pathology , Meningeal Neoplasms/pathology , Meningioma/pathology , Telomerase/metabolism , Telomere/pathology , Astrocytoma/enzymology , Astrocytoma/genetics , Astrocytoma/pathology , Biopsy , Brain Neoplasms/enzymology , Brain Neoplasms/genetics , Glioblastoma/enzymology , Glioblastoma/genetics , Glioblastoma/pathology , Humans , Meningeal Neoplasms/enzymology , Meningeal Neoplasms/genetics , Meningioma/enzymology , Meningioma/genetics , Telomere/ultrastructure
14.
Mech Ageing Dev ; 126(10): 1115-22, 2005 Oct.
Article in English | MEDLINE | ID: mdl-15967485

ABSTRACT

Telomeres, the termini of linear chromosomes, exert a key role in the process of cellular ageing. Progressive telomere shortening is implicated in senescence in vitro and ample evidence exists to support the hypothesis that telomere length is correlated with chronological age and ageing phenotypes in vivo. In this study, we assessed whether mean telomere length of peripheral blood leukocytes predicts age-associated bone loss and/or is related to sex steroid status in an elderly healthy male population (71-86 years). Out of this population, we selected 110 samples for telomere restriction fragment (TRF) length analysis. Fasting blood was analysed for testosterone, estradiol, sex hormone binding globulin and biochemical markers of bone turnover. Also, the bioavailable fractions of sex steroids were calculated. Bone mineral density was measured at baseline and longitudinal follow-up was available for 84 men. We found that mean TRF length was inversely correlated with age (r=-0.19; P=0.049). Although no correlations were found with sex steroids or BMD at baseline, age corrected mean TRF length was associated with longitudinal bone loss for different distal forearm sites (P<0.05). Further studies are required to confirm our results, yet in this study, the predictive value of telomere length for bone loss appears to be substantial, hence underscoring the role of telomere length as a biomarker of ageing phenotypes.


Subject(s)
Aging/blood , Estradiol/blood , Osteoporosis/blood , Telomere/metabolism , Testosterone/blood , Aged , Aged, 80 and over , Aging/genetics , Biomarkers/blood , Bone Density , Humans , Male , Osteoporosis/genetics , Phenotype , Sex Hormone-Binding Globulin/analysis , Telomere/genetics
17.
Nurs Stand ; 14(45): 43-5, 2000.
Article in English | MEDLINE | ID: mdl-11974206

ABSTRACT

To ensure that ethnic minority groups were receiving equality of treatment and service, Horton General Hospital in Banbury formed a multicultural consultation group. The group carried out a five-year plan to standardise health care for ethnic minority communities in Oxfordshire and to educate staff to enhance their cultural sensitivity.


Subject(s)
Benchmarking/organization & administration , Ethnicity , Hospitals, General/organization & administration , Hospitals, Rural/organization & administration , Minority Groups , Attitude of Health Personnel , Attitude to Health/ethnology , Community Participation , Cultural Diversity , England , Ethnicity/psychology , Humans , Inservice Training , Minority Groups/psychology , Personnel, Hospital/education , Personnel, Hospital/psychology , Prejudice , Professional Staff Committees/organization & administration
18.
Article in English | MEDLINE | ID: mdl-1563370

ABSTRACT

Classically, cold induced plasma volume reduction is explained by an increased diuresis which is generated by an inhibition of antidiuretic hormone release. However, most of the haemoconcentration appears to be reversible during rewarming. This observation weakens the former statement. The aim of this study was to clarify the mechanisms involved in the reversal of the cold induced haemoconcentration. Six young males, resting in a dorsal reclining position, were exposed successively to a thermoneutral environment (30 min), a cold environment (1 degrees C; cold) or thermoneutrality (control) for 120 min, and during a 60-min recovery period in thermoneutral conditions. During cold stress, a reduction of 15% (i.e. 510 ml) of the plasma volume was observed, and osmolality was unchanged. After the 60-min recovery under thermoneutral conditions, plasma volume variation between the Cold and the Control experiments was reduced and reached 3% (i.e. 100 ml). This volume equalled the increased amount of urine production observed during the cold stress experiment. Haemoconcentration cannot be explained by increased urinary water loss (+/- 100 ml) alone. Therefore a transient shift of plasma water from vascular to interstitial spaces, due to an increase of blood pressure, could be involved in the reduction of plasma volume.


Subject(s)
Cold Temperature , Plasma Volume/physiology , Adult , Body Temperature , Body Water/metabolism , Diuresis/physiology , Humans , Male , Osmolar Concentration , Oxygen Consumption , Vasopressins/blood
19.
Int J Biometeorol ; 34(1): 1-14, 1990 May.
Article in English | MEDLINE | ID: mdl-2361773

ABSTRACT

The affect of negative thermal stress on hematological variables at rest, and during submaximal (sub ex) and maximal exercise (max ex) were observed for young males who volunteered in two experimental sessions, performed in cold (0 degree C) and in normal room temperature (20 degrees C). At rest, hematological variables such as RBC and derivates Hb and Hct were significantly increased (P less than 0.05) during cold stress exposure, while plasma volume decreased. The findings of this study suggest that the major factor inducing hypovolemia during low thermal stress can be imputed to local plasma water-shift mechanisms and especially to a transient shift of plasma water from intra- to extravascular compartments. Rest values for WBC and platelets (Pla) were also slightly increased during cold stress exposure. However this increase can partly be related to hemoconcentration but also to the cold induced hyperventilation activating the lung circulation. Maximal exhaustive exercise induced, in both experimental temperatures, significant (P less than 0.05) increments of RBC, Hb, Hct, and WBC while plasma volume decreased. However, Pla increase was less marked. On the other hand, cold stress raised slightly the observed variations of the different hematological variables. Submaximal exercise induced a similar, though non-significant, pattern for the different hematological variables in both experimental conditions. Observed plasma volume (delta PV%) reduction appears during exercise. However cold stress induced resting plasma volume variations that are transferred at every exercise level. Neither exercise nor cold inducement significantly modified the hematological indices (MCH, MCV, MCHC). In conclusion hematological variables are affected by cold stress exposure, even when subjects perform a physical activity.


Subject(s)
Blood Physiological Phenomena , Cold Climate/adverse effects , Acclimatization/physiology , Adult , Blood Cell Count , Blood Volume/physiology , Exercise/physiology , Hemoglobins/metabolism , Humans , Male , Stress, Physiological/blood
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