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1.
J Adv Model Earth Syst ; 14(3): e2021MS002784, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35860446

ABSTRACT

Tropical peatlands are among the most carbon-dense ecosystems on Earth, and their water storage dynamics strongly control these carbon stocks. The hydrological functioning of tropical peatlands differs from that of northern peatlands, which has not yet been accounted for in global land surface models (LSMs). Here, we integrated tropical peat-specific hydrology modules into a global LSM for the first time, by utilizing the peatland-specific model structure adaptation (PEATCLSM) of the NASA Catchment Land Surface Model (CLSM). We developed literature-based parameter sets for natural (PEATCLSMTrop,Nat) and drained (PEATCLSMTrop,Drain) tropical peatlands. Simulations with PEATCLSMTrop,Nat were compared against those with the default CLSM version and the northern version of PEATCLSM (PEATCLSMNorth,Nat) with tropical vegetation input. All simulations were forced with global meteorological reanalysis input data for the major tropical peatland regions in Central and South America, the Congo Basin, and Southeast Asia. The evaluation against a unique and extensive data set of in situ water level and eddy covariance-derived evapotranspiration showed an overall improvement in bias and correlation compared to the default CLSM version. Over Southeast Asia, an additional simulation with PEATCLSMTrop,Drain was run to address the large fraction of drained tropical peatlands in this region. PEATCLSMTrop,Drain outperformed CLSM, PEATCLSMNorth,Nat, and PEATCLSMTrop,Nat over drained sites. Despite the overall improvements of PEATCLSMTrop,Nat over CLSM, there are strong differences in performance between the three study regions. We attribute these performance differences to regional differences in accuracy of meteorological forcing data, and differences in peatland hydrologic response that are not yet captured by our model.

3.
Br J Oral Maxillofac Surg ; 58(5): 542-545, 2020 06.
Article in English | MEDLINE | ID: mdl-32245578

ABSTRACT

The aims of this study were to find out whether scoring in a rose-trellis pattern improved the stretch of mucoperiosteal flaps more than conventional scoring in the horizontal plane, and to consider its application in the closure of oroantral communications. Sixteen sections of cadaveric porcine buccal mucoperiosteum were removed from the molar region of the maxilla and mandible. A three-sided flap was raised in the subperiosteal plane, excised, and pinned to a cork board with the periosteal side facing upwards. Eight samples were scored in the horizontal plane (control) using lines perpendicular to the line of simulated advancement, and eight in a rose-trellis or criss-cross pattern. Scoring using a rose-trellis pattern yielded a mean increase in stretch of 24.3% (p=0.0003) when compared with the conventional method. Buccal advancement flaps are widely used to close oroantral communications, and scoring of the mucoperiosteum facilitates the stretching of the tissue over the defect. To be successful, defects should be fully closed to prevent contamination, and closure should be tension-free. In this study, scoring in a rose-trellis pattern increased the stretch of the tissue sample more than scoring in the horizontal plane. The rose-trellis technique therefore could aid the effective closure of oroantral communications.


Subject(s)
Oroantral Fistula , Surgical Flaps , Animals , Mandible , Maxilla , Swine
4.
J Infect Public Health ; 11(1): 85-88, 2018.
Article in English | MEDLINE | ID: mdl-28652125

ABSTRACT

The incidence of Clostridium difficile associated diarrhoea (CDAD) is greater in elderly patients. Probiotics may have a beneficial effect in the prevention of CDAD. However, their effect in elderly orthopaedic patients has not been previously reported. Between April 2013 and April 2014, 105 patients admitted with femoral neck fractures, and who required 3days of antibiotics for infection of any cause, were prescribed the probiotic ACTIMEL until 3days after the last antibiotic dose. The incidence of CDAD was compared with historical controls (April 2011¬タモApril 2012). There was no significant reduction in the incidence of CDAD in patients receiving probiotics (OR: 0.9; 95% CI 0.27¬タモ2.91; p=0.8) and therefore we cannot recommend the use of ACTIMEL containing Lactobacillus casei, Lactobacillus bulgaricus, and Streptococcus thermophiles for this purpose in this patient group.


Subject(s)
Anti-Bacterial Agents/adverse effects , Clostridium Infections/prevention & control , Diarrhea/prevention & control , Lacticaseibacillus casei/physiology , Lactobacillus delbrueckii/physiology , Probiotics/administration & dosage , Streptococcus/physiology , Aged , Aged, 80 and over , Anti-Bacterial Agents/therapeutic use , Female , Femoral Neck Fractures/complications , Humans , Incidence , Male , Treatment Outcome
5.
Int J Cosmet Sci ; 39(1): 72-82, 2017 Feb.
Article in English | MEDLINE | ID: mdl-27380298

ABSTRACT

OBJECTIVES: This work aimed to design, synthesize and characterize replacement natural moisturizing factor (NMF) composed of modified hygroscopic linear amino acids to pre-empt or repair skin barrier dysfunction. METHODS: Following synthesis and characterization, thermo-gravimetric analysis and quantum mechanics molecular modelling quantified and depicted water binding to the new compounds. Deliquescence relative humidity demonstrated the water-scavenging ability of the compounds, whereas snake skin moisturizing studies showed they increased water uptake into snake skin. RESULTS: From thermal analysis, N-hydroxyglycine showed greatest water-holding capacity followed by N-hydroxyserine, l-homoserine and α-hydroxyglycine; coupled with quantum mechanics molecular modelling, between 8 and 12 molecules of water could associate with each molecule of either N-hydroxyglycine, N-hydroxyserine or l-homoserine. All of our modified amino acids were efficacious and induced similar or greater water uptake compared with the established moisturizing compounds hyaluronic acid, glycerine and urea in snake skin. Incorporated at 10% in Oilatum, N-hydroxyserine induced >200% greater moisture uptake into dry snake skin compared to treatment with water alone, with efficacy related to the molecule structure and ability to bind to 12 water molecules. Oilatum cream spiked with all our unnatural amino acid hydrotropes increased water uptake into snake skin compared with Oilatum alone. The compound series was designed to elucidate some structure - efficacy relationships. Amino acid chirality did not affect the water-holding capacity but did affect uptake into skin. Compounds with high melting points and bond energies tended to decrease water-holding capacity. With isosteric replacement, the more electronegative atoms gave greater water-holding capacities. CONCLUSIONS: This work demonstrates the potential of unnatural amino acid hydrotropes as skin moisturizers and has developed some predictive 'rules' for further design and refinement of chemical structures.


Subject(s)
Amino Acids/chemistry , Skin Physiological Phenomena , Animals , Humans , Magnetic Resonance Spectroscopy , Powder Diffraction , Snakes , Spectrophotometry, Infrared , Thermogravimetry , Water Loss, Insensible
6.
Orthod Craniofac Res ; 18 Suppl 2: 14-24, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26567852

ABSTRACT

OBJECTIVES: To compare facial appearance and dento-alveolar relationship outcomes from the CSAG (1998) and CCUK (2013) studies. SETTING AND SAMPLE POPULATION: Five-year-olds born with non-syndromic unilateral cleft lip and palate. Those in the original CSAG were treated in a dispersed model of care with low-volume operators. Those in CCUK were treated in a more centralized, high-volume operator model. MATERIALS AND METHODS: We compared facial appearance using frontal view photographs (252 CCUK, 239 CSAG) and dental relationships using study models (198 CCUK, 223 CSAG). Facial appearance was scored by a panel of six assessors using a standardized and validated outcome tool. Dento-alveolar relationships were scored by two assessors using the 5-Year-Olds' Index. Ordinal regression was used to compare results between surveys. RESULTS: Excellent or good facial appearance was seen in 36.2% of CCUK compared with 31.9% in CSAG. In CCUK, 21.6% were rated as having poor or very poor facial appearance compared with 27.6% in CSAG. The percentage rated as having excellent or good dento-alveolar relationships was 53.0% in CCUK compared with 29.6% in CSAG. In CCUK, 19.2% were rated as having poor or very poor dento-alveolar relationships compared to 36.3% in CSAG. The odds ratios for improved outcome in CCUK compared to CSAG were 1.43 (95% CI 1.03, 1.97) for facial appearance and 2.29 (95% CI 1.47, 3.55) for dento-alveolar relationships. CONCLUSIONS: Facial and dento-alveolar outcomes were better in CCUK children compared to those in CSAG.


Subject(s)
Bone Transplantation , Cleft Lip/surgery , Cleft Palate/surgery , Child, Preschool , Face , Female , Humans , Male , Treatment Outcome
7.
Cell Death Differ ; 22(9): 1540-50, 2015 Sep.
Article in English | MEDLINE | ID: mdl-25744025

ABSTRACT

Prelamin A accumulation and persistent DNA damage response (DDR) are hallmarks of vascular smooth muscle cell (VSMC) ageing and dysfunction. Although prelamin A is proposed to interfere with DNA repair, our understanding of the crosstalk between prelamin A and the repair process remains limited. The extracellular signal-regulated kinases 1 and 2 (ERK1/2) have emerged as key players in the DDR and are known to enhance ataxia telangiectasia-mutated protein (ATM) activity at DNA lesions, and in this study, we identified a novel relationship between prelamin A accumulation and ERK1/2 nuclear compartmentalisation during VSMC ageing. We show both prelamin A accumulation and increased DNA damage occur concomitantly, before VSMC replicative senescence, and induce the localisation of ERK1/2 to promyelocytic leukaemia protein nuclear bodies (PML NBs) at the sites of DNA damage via nesprin-2 and lamin A interactions. Importantly, VSMCs treated with DNA damaging agents also displayed prelamin A accumulation and ERK compartmentalisation at PML NBs, suggesting that prelamin A and nesprin-2 are novel components of the DDR. In support of this, disruption of ERK compartmentalisation at PML NBs, by either depletion of nesprin-2 or lamins A/C, resulted in the loss of ATM from DNA lesions. However, ATM signalling and DNA repair remained intact after lamins A/C depletion, whereas nesprin-2 disruption ablated downstream Chk2 activation and induced genomic instability. We conclude that lamins A/C and PML act as scaffolds to organise DNA-repair foci and compartmentalise nesprin-2/ERK signalling. However, nesprin-2/ERK signalling fidelity, but not their compartmentalisation at PML NBs, is essential for efficient DDR in VSMCs.


Subject(s)
DNA Damage , Microfilament Proteins/metabolism , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/metabolism , Muscle, Smooth, Vascular/cytology , Muscle, Smooth, Vascular/metabolism , Nerve Tissue Proteins/metabolism , Nuclear Proteins/metabolism , Adult , Cell Cycle/physiology , Cellular Senescence/physiology , DNA Repair , Female , Humans , Intranuclear Inclusion Bodies/genetics , Intranuclear Inclusion Bodies/metabolism , Lamin Type A/metabolism , Male , Microfilament Proteins/genetics , Middle Aged , Mitogen-Activated Protein Kinase 1/genetics , Mitogen-Activated Protein Kinase 3/genetics , Muscle, Smooth, Vascular/enzymology , Nerve Tissue Proteins/genetics , Nuclear Proteins/genetics , Transfection , Young Adult
8.
Br J Anaesth ; 114(4): 677-82, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25501722

ABSTRACT

BACKGROUND: Classic teaching suggests that diminished availability of oxygen leads to increased tissue oxygen extraction yet evidence to support this notion in the context of hypoxaemia, as opposed to anaemia or cardiac failure, is limited. METHODS: At 75 m above sea level, and after 7-8 days of acclimatization to 4559 m, systemic oxygen extraction [C(a-v)O2] was calculated in five participants at rest and at peak exercise. Absolute [C(a-v)O2] was calculated by subtracting central venous oxygen content (CcvO2) from arterial oxygen content [Formula: see text] in blood sampled from central venous and peripheral arterial catheters, respectively. Oxygen uptake [Formula: see text] was determined from expired gas analysis during exercise. RESULTS: Ascent to altitude resulted in significant hypoxaemia; median (range) [Formula: see text] 87.1 (82.5-90.7)% and [Formula: see text] 6.6 (5.7-6.8) kPa. While absolute C(a-v)O2 was reduced at maximum exercise at 4559 m [83.9 (67.5-120.9) ml litre(-1) vs 99.6 (88.0-151.3) ml litre(-1) at 75 m, P=0.043], there was no change in oxygen extraction ratio (OER) [C(a-v)O2/CaO2] between the two altitudes [0.52 (0.48-0.71) at 4559 m and 0.53 (0.49-0.73) at 75 m, P=0.500]. Comparison of C(a-v)O2 at peak [Formula: see text] at 4559 m and the equivalent [Formula: see text] at sea level for each participant also revealed no significant difference [83.9 (67.5-120.9) ml litre(1) vs 81.2 (73.0-120.7) ml litre(-1), respectively, P=0.225]. CONCLUSION: In acclimatized individuals at 4559 m, there was a decline in maximum absolute C(a-v)O2 during exercise but no alteration in OER calculated using central venous oxygen measurements. This suggests that oxygen extraction may have become limited after exposure to 7-8 days of hypoxaemia.


Subject(s)
Altitude , Exercise , Oxygen/metabolism , Acclimatization , Adult , Female , Humans , Male , Oxygen Consumption
9.
Environ Pollut ; 203: 227-234, 2015 Aug.
Article in English | MEDLINE | ID: mdl-24998996

ABSTRACT

Turfgrass covers a large fraction of the urbanized landscape, but the carbon exchange of urban lawns is poorly understood. We used eddy covariance and flux chambers in a grassland field manipulative experiment to quantify the carbon mass balance in a Singapore tropical turfgrass. We also assessed how management and variations in environmental factors influenced CO2 respiration. Standing aboveground turfgrass biomass was 80 gC m(-2), with a mean ecosystem respiration of 7.9 ± 1.1 µmol m(-2) s(-1). The contribution of autotrophic respiration was 49-76% of total ecosystem respiration. Both chamber and eddy covariance measurements suggest the system was in approximate carbon balance. While we did not observe a significant relationship between the respiration rates and soil temperature or moisture, daytime fluxes increased during the rainy interval, indicating strong overall moisture sensitivity. Turfgrass biomass is small, but given its abundance across the urban landscape, it significantly influences diurnal CO2 concentrations.


Subject(s)
Carbon Cycle , Carbon/analysis , Poaceae/metabolism , Carbon/chemistry , Carbon Dioxide/analysis , Carbon Dioxide/metabolism , Ecosystem , Rain , Singapore , Soil/chemistry , Temperature
10.
Philos Trans R Soc Lond B Biol Sci ; 365(1555): 3129-47, 2010 Oct 12.
Article in English | MEDLINE | ID: mdl-20819808

ABSTRACT

We are now reaching the stage at which specific genetic factors with known physiological effects can be tied directly and quantitatively to variation in phenology. With such a mechanistic understanding, scientists can better predict phenological responses to novel seasonal climates. Using the widespread model species Arabidopsis thaliana, we explore how variation in different genetic pathways can be linked to phenology and life-history variation across geographical regions and seasons. We show that the expression of phenological traits including flowering depends critically on the growth season, and we outline an integrated life-history approach to phenology in which the timing of later life-history events can be contingent on the environmental cues regulating earlier life stages. As flowering time in many plants is determined by the integration of multiple environmentally sensitive gene pathways, the novel combinations of important seasonal cues in projected future climates will alter how phenology responds to variation in the flowering time gene network with important consequences for plant life history. We discuss how phenology models in other systems--both natural and agricultural--could employ a similar framework to explore the potential contribution of genetic variation to the physiological integration of cues determining phenology.


Subject(s)
Adaptation, Physiological/physiology , Arabidopsis/growth & development , Climate Change , Flowers/growth & development , Adaptation, Physiological/genetics , Arabidopsis/genetics , Arabidopsis/physiology , Flowers/genetics , Flowers/physiology , Photoperiod , Seasons , Temperature
11.
Emerg Med J ; 26(5): 351-3, 2009 May.
Article in English | MEDLINE | ID: mdl-19386870

ABSTRACT

BACKGROUND: The oculovagal reflex is well described in ophthalmic surgery, but may be caused by any manner of pressure on the globe. Children with orbital blowout fractures present in a different manner from adults. The classic presentation in children is a white eye injury (ie, no subconjunctival haemorrhage) with upgaze diplopia and general malaise. METHODS: A retrospective audit is presented of paediatric and young adult patients referred to the Orbital Service at St George's Hospital who required surgical intervention. RESULTS: One-third of children with orbital blowout fractures are admitted for head injury observations, while the true cause for the symptoms goes unrecognised and uninvestigated. CONCLUSIONS: Orbital blowout fractures in children require more swift intervention than in adults if muscle ischaemia and permanent impairment of the vision is to be avoided. The delay for head injury observation may therefore compromise the surgical outcome.


Subject(s)
Orbital Fractures/physiopathology , Reflex, Oculocardiac , Adolescent , Bradycardia/etiology , Child , Child, Preschool , Craniocerebral Trauma/diagnosis , Diagnosis, Differential , Humans , Male , Nausea/etiology , Orbital Fractures/diagnosis , Orbital Fractures/surgery , Retrospective Studies , Treatment Outcome , Vagus Nerve/physiopathology , Vomiting/etiology , Young Adult
13.
Proc Inst Mech Eng H ; 220(2): 253-68, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16669392

ABSTRACT

Hip resurfacing has an enduring appeal because of the advantages of bone conservation and maximal joint stability. However, a far from satisfactory experience with earlier resurfacing designs led to its virtual disappearance in the 1980s. The concept was reintroduced in the late 1990s. The current generation of resurfacing devices generally consisted of a large-diameter metal-on-metal articulation, the femoral components being cemented and the acetabular components utilizing various forms of cementless fixation. The encouraging medium-term results, with a follow-up of up to 8 years using the current generation of surface replacement joints, combined with favourable reports related to long-term performance of some metal bearings have led to a rapid increase in the use of such components with these devices. This trend is most marked in younger, more active patients who have expectations of restoration of lifestyle in addition to improved mobility and pain relief and in whom failure with conventional total hip replacement is much higher than previously reported with more sedentary patients. The aim of this paper is, firstly, to highlight a number of areas of improvement and, secondly, to explain how these may be addressed by making modifications to the design of both implants and instrumentation and to the surgical technique. The areas identified for improvement were tissue preservation (thinner components, and reduced steps between sizes), acetabular cup issues (fixation, insertion, and positioning), femoral component issues (design, loading, and cementation), improved bearing surface characteristics, and simplified precise instrumentation with a low-trauma surgical technique.


Subject(s)
Arthroplasty, Replacement, Hip/instrumentation , Arthroplasty, Replacement, Hip/trends , Biocompatible Materials/chemistry , Hip Prosthesis/trends , Metals/analysis , Metals/chemistry , Arthroplasty, Replacement, Hip/methods , Friction , Lubrication , Materials Testing , Prosthesis Design/methods , Prosthesis Design/trends , Science/instrumentation , Science/methods , Science/trends , Surface Properties
14.
Proc Inst Mech Eng H ; 220(2): 385-98, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16669404

ABSTRACT

Metal-on-metal (MOM) bearings offer extremely low wear and the avoidance of polyethylene but generate metallic wear particles. Although their total volume is dramatically smaller than polyethylene debris, these particles are in the nanometre size range and are many times more numerous. Metallic particles are ingested by macrophages or may be disseminated via lymphatics to the reticuloendothelial system. They corrode, and metal ions are present in the circulation and concentrated in erythrocytes. Excretion of metal ions via the kidneys seems to balance their generation in patients with MOM implants. However, highly sensitive detection methods can be used to show that levels of circulating cobalt and chromium ions are several times the normal level. These concentrations are well within the limits identified as dangerous to health in workers exposed to industrial chemicals, and also considerably lower than the levels found to cause cell toxicity in vitro. The local concentrations of particles and metal ions in the synovial tissue may occasionally exceed these limits and cause tissue necrosis. Clinical experience of lysis is rare in association with MOM bearings, as are hypersensitivity reactions and MOM bearings have had an excellent record over four decades and have a favourable benefit to risk ratio. Further reduction in risk will be achieved by improvement of materials, engineering, and accuracy of insertion.


Subject(s)
Bone Neoplasms/chemically induced , Chromium Alloys/adverse effects , Hip Prosthesis/adverse effects , Prosthesis Failure , Prosthesis-Related Infections/chemically induced , Bone Neoplasms/epidemiology , Hip Prosthesis/statistics & numerical data , Humans , Ions/adverse effects , Metals/adverse effects , Prosthesis-Related Infections/epidemiology , Risk Assessment
15.
Plant Dis ; 89(7): 700-704, 2005 Jul.
Article in English | MEDLINE | ID: mdl-30791238

ABSTRACT

Russet symptoms of unknown etiology are sporadically observed on snap bean (Phaseolus vulgaris) pods in New York and Maryland. Symptoms can render the whole crop unmarketable, and seem to appear when heavy rainfall occurs around harvest time. In 2000 and 2004, a microorganism not previously encountered was isolated from russet lesions on snap bean pods from commercial fields in Maryland and New York. Typical russet symptoms were produced on snap bean pods of cv. Brio after inoculation with spores of the isolates. Koch's postulates were also fulfilled. The organism was identified as Plectosporium tabacinum (Van Beyma) M.E. Palm, W. Gams & Nirenberg. A continuous 48-h leaf wetness duration at 23 to 27°C was essential for rapid symptom development. Large (11 cm long on average) snap bean pods were more susceptible to disease than smaller (pin) pods in cvs. Brio and Gold Mine. Light mechanical damage to the pods did not enhance infection. Four isolates of P. tabacinum (three from snap bean pods, one from zucchini) were inoculated onto large pods of the snap bean cvs. Brio, Gold Mine, and Hercules. All four isolates induced a russet on the pods, but the severity was significantly lower with the zucchini isolate.

16.
Acta Psychiatr Scand ; 110(4): 292-8, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15352931

ABSTRACT

OBJECTIVE: Treatment options are very limited for individuals with schizophrenia resistant to clozapine. We tested the hypothesis that amisulpride augmentation would lead to an improvement in these patients. METHOD: This was an open non-randomized study. Thirty-three patients with sub-optimal response to clozapine were commenced on amisulpride in addition to clozapine. Clinical status was evaluated at baseline, 3 and 6 months using the Positive And Negative Syndrome Scale (PANSS), Scale for the Assessment of Negative Symptoms (SANS), Global Assessment Scale (GAS), Calgary Depression Scale, Calgary Anxiety Scale and various side effect rating scales. RESULTS: Twenty-eight subjects completed 6 months treatment on clozapine and amisulpride. There was a statistically significant improvement in the mean scores for PANSS, SANS and GAS at follow-up and no significant changes in side effect ratings. CONCLUSION: Co-administration of amisulpride, in a group of patients partially or non-responsive to clozapine, may lead to a substantial improvement in positive and negative symptoms, without worsening the side effect burden.


Subject(s)
Antipsychotic Agents/therapeutic use , Clozapine/therapeutic use , Schizophrenia/drug therapy , Sulpiride/analogs & derivatives , Sulpiride/therapeutic use , Amisulpride , Brief Psychiatric Rating Scale , Diagnostic and Statistical Manual of Mental Disorders , Drug Synergism , Drug Therapy, Combination , Female , Humans , Male , Schizophrenia/diagnosis
18.
Toxicol Sci ; 64(2): 269-80, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11719710

ABSTRACT

Bromodichloromethane (BDCM) is a common municipal drinking water disinfection by-product, resulting in widespread trace human exposure via ingestion and inhalation. The present studies were designed to define organ-specific, BDCM-induced toxicity in wild type (p53(+/+)) and heterozygous (p53(+/-)) mice on both the FVB/N and C57BL/6 genetic backgrounds. Mice were exposed to BDCM vapor daily for 6 h/day and 7 days/week at concentrations of 0, 1, 10, 30, 100, or 150 ppm for 1 week and at 0, 0.3, 1, 3, 10, or 30 ppm for 3 weeks. In the 1-week exposure study, dose-dependent mortality and morbidity were observed at concentrations of 30 ppm and above and were as high as 100% at 150 ppm. In the 3-week exposure study, mortality and morbidity were found only in the 30-ppm exposure groups and were 0, 17, 67, and 33% for the wild-type C57BL/6, p53(+/-) C57BL/6, wild-type FVB/N, and p53(+/-) FVB/N mice, respectively. BDCM was a particularly potent kidney cytotoxicant. Dose-dependent tubular degeneration, necrosis, and associated regenerative cell proliferation greater than 10-fold over controls were seen at concentrations as low as 10 ppm in the kidneys of all strains at 1 week. Similar dose-dependent increases in hepatic necrosis, degeneration, and regenerative cell proliferation were observed but were induced only at concentrations of 30 ppm and higher. Pathological changes were more severe in the FVB/N compared to the C57BL/6 mice and were more severe in the heterozygotes compared to the wild-type mice. However, recovery and return of the percentage of kidney cells in S-phase to control levels was seen at 3 weeks. The estimated maximum tolerated dose for longer-term exposures was 15 ppm, based on mortality, induced kidney pathology, and regenerative cell proliferation. A one-year cancer bioassay was initiated with doses of 0, 0.5, 3, 10, and 15 ppm, based on this information. No pathological changes in the livers were found at the 13-week time point of that study. At 13 weeks, the kidney lesions and regenerative cell proliferation seen at the 1-week time point at doses of 10 ppm and above had resolved, and the cell proliferation rates had returned to baseline. Differences in toxicity indicate that caution be used in substituting wild-type mice for transgenic mice for range-finding studies to select doses for p53(+/-) cancer studies. Resolution of the kidney lesions indicates that periods of very high regenerative cell proliferation, potentially important in the carcinogenic process, may not be observed if measurements are taken only at 3 weeks of exposure or later.


Subject(s)
Carcinogens/toxicity , Kidney/drug effects , Liver/drug effects , Trihalomethanes/toxicity , Tumor Suppressor Protein p53/genetics , Animals , Body Weight/drug effects , Carcinogens/administration & dosage , Chemical and Drug Induced Liver Injury , Genotype , Heterozygote , Inhalation Exposure , Kidney/pathology , Kidney Diseases/chemically induced , Kidney Diseases/mortality , Kidney Diseases/pathology , Liver/pathology , Liver Diseases/mortality , Liver Diseases/pathology , Mice , Mice, Inbred C57BL , Mice, Inbred Strains , Organ Size/drug effects , Species Specificity , Time Factors , Trihalomethanes/administration & dosage
19.
Soc Sci Med ; 53(11): 1503-11, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11710425

ABSTRACT

Spirituality has become a construct of interest in American health care: however, there remains a limited understanding of how patients themselves describe spirituality and view its impact on their health and well-being. The purpose of this study was to identify and describe elements of patient-reported, health-related spirituality. A qualitative study utilized focus group interviews of 17 women with type 2 diabetes mellitus and 18 women with no self-identified illness. Purposeful sampling of participants who had prior experiences in healthcare settings, with or without a chronic illness, guided the sampling strategy. Editing analysis of the interview transcripts were coded into conceptual categories. Participant narratives were grouped into eight general categories: (1) change in functional status, (2) core beliefs, (3) medical/disease state information gathering and processing, (4) interpretation and understanding, (5) life scheme, (6) positive intentionality, (7) agency, and (8) subjective well-being. A change in functional status was the catalyst for two process-oriented categories; medical/disease state information gathering and processing, and the higher-order interpretation and understanding, or meaning making of life events. Core beliefs were sources that grounded and maintained an interpretative structure through which participants viewed their life events and positively framed their experiences. Life scheme described a heuristic framework through which all life events were viewed. Positive intentionality was participant belief in the capacity to execute a specific action that was required for a desired outcome. Participants tied the attitudes and practices of positive intentionality with agency, or the use or exertion of power through belief, practice, or community. Participants outlined both a positive affective and cognitive component of subjective well-being. Patients describe several interrelated elements and a process of events in their depiction of spirituality in healthcare settings. Patient-reported spirituality is predominantly a cognitive construct incorporating the domains of life scheme and positive intentionality.


Subject(s)
Diabetes Mellitus , Health Status , Spirituality , Adult , Aged , Chronic Disease , Diabetes Mellitus/psychology , Female , Focus Groups , Humans , Middle Aged
20.
Int Immunopharmacol ; 1(2): 349-53, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11360935

ABSTRACT

Guinea pigs are a classic animal model for studying delayed-type hypersensitivity (DTH) reactions. However, skin irritation due to hair removal can interfere with the evaluation of the modulation of these responses by various mediators. A DTH model using hairless (IAF/HA-HO) guinea pigs, sensitized with complete Freund's adjuvant and repeatedly skin tested with tuberculin, purified protein derivative, (PPD) has therefore been developed. At 10 weeks after sensitization, intradermal PPD elicited minimal erythema at 6 h, which increased over the next 18 h to a maximum at 24 h, and declined by 48 h. The response could be quantified by bioassay using graded doses of PPD. Reactions at 24 h were characterized by predominantly mononuclear cell deep and superficial dermal infiltrates. Dermal DTH in hairless guinea pigs is thus, grossly and histologically similar to that seen in Hartley guinea pigs.


Subject(s)
Disease Models, Animal , Hypersensitivity, Delayed/etiology , Tuberculin/immunology , Animals , Guinea Pigs , Immunization , Male
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