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Hastings RP, Horne S, Mitchell G. Burnout in direct care staff in intellectual disability services: a factor analytic study of the Maslach Burnout Inventory. JOURNAL OF INTELLECTUAL DISABILITY RESEARCH : JIDR 2004; 48:268-273. [PMID: 15025670 DOI: 10.1111/j.1365-2788.2003.00523.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
BACKGROUND There is gathering research interest in the well-being of staff working in services for people with intellectual disability (ID), including the assessment of burnout and its correlates. However, no previous studies have considered the applicability of the main three dimensions of burnout to staff in ID services. METHODS Data were analysed from two samples of staff (total n=184) who participated in research studies that included completion of the Maslach Burnout Inventory (MBI). RESULTS Nineteen of the MBI items loaded clearly onto factors closely resembling the three original subscales: emotional exhaustion, depersonalization and personal accomplishment. Internal consistency for the three MBI subscales was fair to good (range 0.68-0.87). CONCLUSIONS The original three MBI dimensions were found to be highly relevant to the present sample of staff. The analyses support the construct validity and reliability of the MBI for staff in ID services.
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Wilson PDG, Wilson DR, Brocklehurst TF, Coleman HP, Mitchell G, Waspe CR, Jukes SA, Robins MM. Batch growth of Salmonella typhimurium LT2: stoichiometry and factors leading to cessation of growth. Int J Food Microbiol 2004; 89:195-203. [PMID: 14623385 DOI: 10.1016/s0168-1605(03)00142-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Salmonella typhimurium LT2 was grown in batch culture (trypticase soy broth, with 0.3%(w/v) yeast extract, 1% (w/v) glucose and 0.5% (w/v/) NaCl, 20 degrees C) at a range of initial pH (4.4, 4.8, 5.0 and 7.0). The consumption of oxygen and glucose was found to be independent of initial pH, and stoichiometric with growth. Mean yield coefficients of 6.9 x 10(-15) and 15.5 x 10(-15) mol oxygen/cell were estimated. Calculation of the instantaneous state of carbon during the cultivation showed stoichiometric conversion of glucose into biomass, carbon dioxide and organic acids. The concentration of the undissociated form of the primary acidic product (acetic acid) was shown to be the factor limiting growth.
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Maloney SK, Fuller A, Kamerman PR, Mitchell G, Mitchell D. Variation in body temperature in free-ranging western grey kangaroos Macropus fuliginosus. AUSTRALIAN MAMMALOGY 2004. [DOI: 10.1071/am04135] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Using implanted temperature loggers we measured temperature in the carotid artery in five (4
male, 1 female) western grey kangaroos (Macropus fuliginosus) every 5 min for between 39 and
74 days. Dry bulb temperature during the study ranged from an average minimum of (mean �
SD) 11 � 3�C to maximum of 24 � 5�C. Black globe temperature measured in the southern
shade of a grass tree, the habitat chosen by kangaroos during the day, ranged from an average
minimum of 10 � 4�C to an average maximum of 30 � 6�C. There were nine days where
maximum shade globe temperature exceeded 40�C. Carotid blood temperature averaged
36.5 � 0.1�C (n = 5), ranging from an average minimum of 35.5 � 0.3�C to a maximum of 37.3
� 0.1�C The resultant average daily range was 1.8 � 0.3�C. Body temperature was highest
during the night and dropped rapidly early in the morning, reaching a nadir at 1000 hours, after
ambient temperature and solar radiation had begun increasing. Body temperature then rose
gradually during the day to reach a peak in the early evening. The nychthemeral variation in
carotid blood temperature was largely independent of ambient conditions. There was a weak but
significant association between early morning radiation levels and the minimum body
temperature reached, suggesting that peripheral warming influences the morning decrease in
core temperature.
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104
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Mitchell G, Ardern-Jones A, Kissin Mchir M, Taylor R, Eeles RA. A paradox: urgent BRCA genetic testing. Fam Cancer 2003; 1:25-9. [PMID: 14574012 DOI: 10.1023/a:1011570302078] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Diagnostic or predictive testing for germline mutations in cancer predisposition genes is inherently slow as result of both genetic counselling and mutation analysis. The overall time taken for mutation testing is not generally perceived as harmful to the individual and may be positively beneficial in order to permit full reflection on the implication of the genetic test results. However, we present three cases where we considered urgent genetic testing for the presence of mutations in th BRCA 1 and 2 genes to be necessary as the test result would have altered the subsequent clinical management of these individuals or their families.
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105
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Welsh FKS, McFall M, Mitchell G, Miles WFA, Woods WGA. Pre-operative short-course radiotherapy is associated with faecal incontinence after anterior resection. Colorectal Dis 2003; 5:563-8. [PMID: 14617241 DOI: 10.1046/j.1463-1318.2003.00480.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To determine the contribution of total mesorectal excision (TME), short-course pre-operative radiotherapy (SCRT), the level of the anastomosis and other putative contributory factors to the incidence and degree of faecal incontinence after anterior resection of the rectum. PATIENTS AND METHODS Survivors of anterior resection of the rectum performed between February 1996 and February 2001, with a functioning anastomosis, were asked to complete a telephone questionnaire regarding their current bowel habit. Faecal incontinence was scored using the St. Mark's Incontinence Score. RESULTS The median age of 124 patients who completed the questionnaire was 76 years. Of these, 104 patients had neoplastic disease, 66 (53%) patients exhibited some degree of incontinence, median St. Marks' Score 6, interquartile range 3-10. There was a significant association between the anastomotic level, and the St. Mark's Score (P < 0.0001, linear regression). Male sex (P = 0.047), SCRT (P = 0.0014) and an anastomotic leak (P = 0.038) were associated with significantly higher incontinence scores. Age, splenic flexure mobilization, TME, anastomotic configuration or use of a temporary stoma had no detectable independent effect on incontinence scores. CONCLUSIONS Poor functional outcome following anterior resection was associated with a low anastomosis, SCRT or an anastomotic leak. The finding that SCRT was a predictor of postoperative incontinence emphasizes the need for stringent patient selection for this treatment modality.
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106
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Schachter M, Mitchell G, Niziol C, Abhyankar BA. Antihypertensive efficacy of moxonidine in primary care: a 'real-life' study. Int J Clin Pract 2003; 57:479-82. [PMID: 12918886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/04/2023] Open
Abstract
Both clinical trials and everyday experience indicate that most hypertensive patients will need two or more drugs to reach target blood pressures. The current framework for the selection of drugs for combination therapy is based mainly on their interaction with the renin-angiotensin system. However, this approach would not fully exploit the range of drugs now available. This study, based on current primary care practice, confirms that the centrally acting drug moxonidine has efficacy as an add-on agent comparable to that of other drugs such as beta-blockers and ACE inhibitors and that it can effectively be combined with these agents. It also shows that moxonidine is as well tolerated as the other drugs and much better than older centrally acting agents such as clonidine and methyldopa. The study reinforces the view that moxonidine can be considered as an effective and well-tolerated drug for use in combination with any other class of antihypertensives.
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107
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Mitchell G, Jenkins C, Scicchitano R, Dubinfeld A, Kottakis J. O formoterol e uma dose média/ elevada de corticosteróides inalados são mais eficazes do que uma dose elevada de corticosteróides na asma moderada e grave. REVISTA PORTUGUESA DE PNEUMOLOGIA 2003. [DOI: 10.1016/s0873-2159(15)30676-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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108
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Abstract
The malaria parasite Plasmodium falciparum is a complex eukaryote parasite with a dynamic pattern of genomic expression, enabling it to exploit a series of different habitats in human and mosquito hosts. In the human bloodstream, the parasite grows and multiplies within red blood cells and modifies them in various ways to gain nutrients and combat the host's defences, before escaping and invading new red blood cells by a multi-step process. These events are reflected in the constantly changing structure of the organism during the red blood cell cycle.
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109
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Shaw K, Wagner I, Eastwood H, Mitchell G. A qualitative study of Australian GPs' attitudes and practices in the diagnosis and management of attention-deficit/hyperactivity disorder (ADHD). Fam Pract 2003; 20:129-34. [PMID: 12651785 DOI: 10.1093/fampra/20.2.129] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The importance of general practice involvement in the care of attention-deficit/ hyperactivity disorder (ADHD) is increasing due to the rising numbers of patients who present with the disorder. It has been suggested by consensus bodies that GPs should be identifying and referring patients at the severe end of the ADHD spectrum and managing those with less severe symptoms. However, GPs' views of their role in ADHD care are unknown. OBJECTIVE Our aim was to explore the attitudes and practices of Australian GPs towards the diagnosis and management of ADHD. METHODS We conducted a series of focus groups to explore GPs' beliefs regarding the causes of ADHD, their perceived role in ADHD diagnosis and management and their views on the role of behaviour therapies and pharmacotherapies in ADHD management. The subjects were 28 GPs in six focus groups. RESULTS GPs in this study did not want to be the primary providers of care for patients with ADHD. Participants indicated a preference to refer the patient to medical specialists for diagnosis and treatment of ADHD, and expressed low levels of interest in becoming highly involved in ADHD care. Concerns about overdiagnosis and misdiagnosis of the disorder, diagnostic complexity, time constraints, insufficient education and training about the disorder, and concerns regarding misuse and diversion of stimulant medications were the reasons cited for their lack of willingness. CONCLUSIONS The Australian GPs in this study identify a role for themselves in ADHD care which is largely supportive in nature, and involves close liaison with specialist services.
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Fuller A, Kamerman PR, Maloney SK, Mitchell G, Mitchell D. Variability in brain and arterial blood temperatures in free-ranging ostriches in their natural habitat. J Exp Biol 2003; 206:1171-81. [PMID: 12604577 DOI: 10.1242/jeb.00230] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We used implanted miniature data loggers to measure brain (in or near the hypothalamus) and carotid arterial blood temperatures at 5 min intervals in six free-ranging ostriches Struthio camelus in their natural habitat, for a period of up to 14 days. Carotid blood temperature exhibited a large amplitude (3.0-4.6 degrees C) circadian rhythm, and was positively correlated with air temperature. During the day, brain temperature exceeded carotid blood temperature by approx. 0.4 degrees C, but there were episodes when brain temperature was lowered below blood temperature. Selective brain cooling, however, was not present in all ostriches, and was not tightly coupled to the prevailing body temperature. Brain temperature was maintained within narrow daily limits of approx. 2 degrees C, and varied significantly less than blood temperature at short time scales of 5 to 20 min. At night, brain temperature exceeded blood temperature by as much as 3 degrees C. We attribute the elevated brain temperatures to warming of cerebral arterial blood, by reduced heat exchange in the ophthalmic rete or possibly heat gain from cranial structures, before supplying the hypothalamus. Further studies are necessary to elucidate the significance of such variations in brain temperature and the importance of selective brain cooling in free-living birds.
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111
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Mitchell G, Hucker T, Venn R, Wakeling H, Forni L. Pathophysiology and clinical implications of perioperative fluid excess. Br J Anaesth 2003; 90:395; author reply 395-6. [PMID: 12594159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
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112
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Mitchell G, Hucker T, Venn R, Wakeling H, Forni L. Pathophysiology and clinical implications of perioperative fluid excess. Br J Anaesth 2003. [DOI: 10.1093/bja/aeg526] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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113
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Mitchell G, Gray S, Shipton B, Woolley R, Erbacher J, Egerton G, McKnoulty J. Evaluating integrated urban water systems alternatives for Brisbane, Australia. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2003; 47:1-9. [PMID: 12793655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The Brazil Development Study investigates the feasibility of alternative approaches to providing sustainable water services to a 226 ha mixed residential and industrial greenfield development within the city of Brisbane, Australia. The alternatives include techniques such a the use of rainwater tanks, water use efficiency, a local wastewater treatment plant for recycling of reclaimed water and composting toilets amongst others. This paper evaluates a series of urban development scenarios against the objectives of the study. The insights gained into the drivers for cost and environmental impact for this particular site are discussed as well as a number of issues of concern and challenges to Council and the community.
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114
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Price D, Thomas M, Mitchell G, Niziol C, Featherstone R. Improvement of asthma control with a breath-actuated pressurised metred dose inhaler (BAI): a prescribing claims study of 5556 patients using a traditional pressurised metred dose inhaler (MDI) or a breath-actuated device. Respir Med 2003; 97:12-9. [PMID: 12556005 DOI: 10.1053/rmed.2002.1426] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A relationship has been reported between sub-optimal inhaler technique and control of asthma symptoms. Randomised controlled trials and systematic reviews may fail to accurately represent this relationship, by excluding patients who are unable to correctly use the reviewed devices. Breath actuated inhalers (BAIs) are reported to be easier to use than metered dose inhalers (MDIs). This study uses a large primary care medical record database (DIN-LINK) to examine the 'real-life' clinical effectiveness of a BAI vs. traditional MDIs. A comparison is made between the quantity of asthma-related medication (beta2 agonist, oral steroids and antibiotics) and healthcare resource use required by children (0-12 years) and adults (13+ years) using either the BAI or an MDI over a 12-month period. Out of 5556 new asthma patients who met the inclusion criteria, 306 used a BAI and 5250 used a traditional MDI. Children and adults using the BAI received fewer prescriptions for all three medication types than those using a traditional MDI (children: beta2 agonists -18% P=0.036, oral steroids -88% P<0.05, antibiotics -68% P<0.05 and adults: beta2 agonists -10.9% P=0.179, oral steroids -51.2% P<0.05, antibiotics -19.5% P=0.276). All prescription results reached statistical significance, with the exception of beta2 agonist and antibiotic prescription numbers for adult patients. Children and adults using the BAI required less GP consultations for asthma (children -30.3%, P<0.05 and adults -22.9%, P<0.05) and less GP consultations for respiratory infections than those using a traditional MDI (children -35.2%, P=0.001 and adults -10.4%, P=0.236). Adults using the BAI required less outpatient appointments than adults using an MDI (-43.7%, P=0.166). All non-prescription resource results reached statistical significance with the exception of GP consultations for respiratory infections and outpatient visits in the adult group. In conclusion, children and adults using the BAI appear to have better asthma control than children and adults using an MDI as evidenced by fewer relief medication prescriptions and less healthcare resource use.
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115
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Pitts NI, Mitchell G. In vitro succinylcholine hydrolysis in plasma of the African elephant (Loxodonta africana) and impala (Aepyceros melampus). Comp Biochem Physiol C Toxicol Pharmacol 2003; 134:123-9. [PMID: 12524024 DOI: 10.1016/s1532-0456(02)00216-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In elephants the time lapsed from i.m. injection of an overdose of the muscle relaxant succinylcholine (SuCh) until death, is significantly longer than in impala. To determine a difference in the rate of SuCh hydrolysis, once the drug enters the circulation, contributes to this phenomenon we have measured the rate of hydrolysis of SuCh in elephant and impala plasma, and by elephant erythrocytes. Rate of hydrolysis was determined by incubating SuCh in plasma or erythrocyte lysate at 37 degrees C and quantifying the choline produced. Plasma SuCh hydrolytic activity in elephant plasma (12.1+/-1.7 Ul(-1) mean+/-S.D.; n=9) was significantly higher than it was in impala plasma (6.6+/-0.6 Ul(-1); n=5), but were approximately 12 and 21 times lower, respectively, than in human plasma. Elephant erythrocyte lysate had no SuCh hydrolytic activity. Applying this data to previous studies, we can show that the ratio of SuCh absorption to SuCh hydrolysis is expected to be 1.25:1 and 1.41:1 for elephants and impala respectively. It will thus take at least 1.7 times longer for elephant to achieve a plasma SuCh concentration similar to that in impala. We conclude that a more rapid hydrolysis of SuCh in elephant plasma is one factor that contributes to the longer time to death compared to impala.
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116
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Sodha N, Bullock S, Taylor R, Mitchell G, Guertl-Lackner B, Williams RD, Bevan S, Bishop K, McGuire S, Houlston RS, Eeles RA. CHEK2 variants in susceptibility to breast cancer and evidence of retention of the wild type allele in tumours. Br J Cancer 2002; 87:1445-8. [PMID: 12454775 PMCID: PMC2376278 DOI: 10.1038/sj.bjc.6600637] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2002] [Accepted: 09/12/2002] [Indexed: 11/08/2022] Open
Abstract
We have recently shown that the CHEK2*1100delC mutation acts as a low penetrance breast cancer susceptibility allele. To investigate if other CHEK2 variants confer an increased risk of breast cancer, we have screened an affected individual with breast cancer from 68 breast cancer families. Five of these individuals were found to harbour germline variants in CHEK2. Three carried the 1100delC variant (4%). One of these three individuals also carried the missense variant, Arg180His. In the other two individuals, missense variants, Arg117Gly and Arg137Gln, were identified. These two missense variants reside within the Forkhead-associated domain of CHEK2, which is important for the function of the expressed protein. None of these missense variants were present in 300 healthy controls. Microdissected tumours with a germline mutation showed loss of the mutant allele suggesting a mechanism for tumorigenesis other than a loss of the wild type allele. This study provides further evidence that sequence variation in CHEK2 is associated with an increased risk of breast cancer, and implies that tumorigenesis in association with CHEK2 mutations does not involve loss of the wild type allele.
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117
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Vuillaumier-Barrot S, Le Bizec C, de Lonlay P, Barnier A, Mitchell G, Pelletier V, Prevost C, Saudubray JM, Durand G, Seta N. Protein losing enteropathy-hepatic fibrosis syndrome in Saguenay-Lac St-Jean, Quebec is a congenital disorder of glycosylation type Ib. J Med Genet 2002; 39:849-51. [PMID: 12414827 PMCID: PMC1735008 DOI: 10.1136/jmg.39.11.849] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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118
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Pitts NI, Mitchell G. Pharmacokinetics and effects of succinylcholine in African elephant (Loxodonta africana) and impala (Aepyceros melampus). Eur J Pharm Sci 2002; 15:251-60. [PMID: 11923057 DOI: 10.1016/s0928-0987(01)00215-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The phenomenon of slow onset of succinylcholine (Sch) effect in elephants was investigated by analyzing blood concentrations of Sch and its metabolite choline in elephant and impala. To assess whether the slow onset phenomenon is related to the pharmacokinetics of Sch following i.m. administration, we analyzed the time course of plasma concentrations of intact drug and its metabolite and determined its pharmacological effects. Blood samples were obtained from anaesthetized elephant (n=6) and impala (n=7) following i.m. administration of a lethal dose of Sch. Time from Sch injection to onset of apnoea and to death was significantly longer for elephant than impala (mean+/-S.D. apnoea 4.4+/-1.5 and 2.3+/-0.9 min, respectively; death 32.6+/-7.3 and 6.2+/-3.4 min, respectively). The C(max) was not different between elephants and impala (20.3+/-7.9 vs. 14.4+/-6.8 nmol ml-1, respectively) but the t(max) was significantly longer for elephants (23.0+/-7.6 vs. 3.7+/-2.2 min). Analysis of the plasma Sch and choline concentrations over time revealed that the relative amount of Sch entering the circulation within the first 30 s after i.m. injection is greater for impala than elephant. No greater rate in the plasma hydrolysis of Sch in elephant compared to impala was apparent.
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119
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Mitchell D, Maloney SK, Jessen C, Laburn HP, Kamerman PR, Mitchell G, Fuller A. Adaptive heterothermy and selective brain cooling in arid-zone mammals. Comp Biochem Physiol B Biochem Mol Biol 2002; 131:571-85. [PMID: 11923074 DOI: 10.1016/s1096-4959(02)00012-x] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Adaptive heterothermy and selective brain cooling are regarded as important thermal adaptations of large arid-zone mammals. Adaptive heterothermy, a process which reduces evaporation by storing body heat, ought to be enhanced by ambient heat load and by water deficit, but most mammals studied fail to show at least one of those attributes. Selective brain cooling, the reduction of brain temperature below arterial blood temperature, is most evident in artiodactyls, which possess a carotid rete, and traditionally has been considered to protect the brain during hyperthermia. The development of miniature ambulatory data loggers for recording body temperature allows the temperatures of free-living wild mammals to be measured in their natural habitats. All the African ungulates studied so far, in their natural habitats, do not exhibit adaptive heterothermy. They have low-amplitude nychthemeral rhythms of temperature, with mean body temperature over the night exceeding that over the day. Those with carotid retes (black wildebeest, springbok, eland) employ selective brain cooling but zebra, without a rete, do not. None of the rete ungulates, however, seems to employ selective brain cooling to prevent the brain overheating during exertional hyperthermia. Rather, they use it at rest, under moderate heat load, we believe in order to switch body heat loss from evaporative to non-evaporative routes.
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120
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Welsh F, MacFall M, Mitchell G, Miles W, Woods W. Moynihan 07. Br J Surg 2002. [DOI: 10.1046/j.1365-2168.89.s.1.15_7.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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121
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Maloney SK, Fuller A, Mitchell G, Mitchell D. Brain and arterial blood temperatures of free-ranging oryx ( Oryx gazella). Pflugers Arch 2002; 443:437-45. [PMID: 11810215 DOI: 10.1007/s004240100704] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2001] [Revised: 06/26/2001] [Accepted: 08/02/2001] [Indexed: 10/27/2022]
Abstract
We used implanted miniature data loggers to measure brain and arterial blood temperatures every 5 min for up to 15 days in four free-ranging oryx ( Oryx gazella) in their natural habitat. Globe temperatures exceeded 45 degrees C and average peak radiant heat load was 800 W.m(-2). Arterial blood temperature exhibited a moderate amplitude nychthemeral rhythm of 1.8+/-0.3 degrees C (mean +/-SD). The amplitude of the nychthemeral rhythm was not influenced by variations in ambient heat load. Average brain temperature exceeded carotid arterial blood temperature by 0.29 degrees C but there was a range of body temperatures over which the brain could be up to 0.4 degrees C cooler or 0.5 degrees C warmer than arterial blood. At high body temperatures (>39.5 degrees C) at rest, three of the animals tended to maintain the brain cooler than arterial blood. During exercise the brain was always warmer than arterial blood. The slope of the regression line relating brain temperature to carotid blood temperature was less than one. At short time scales of 5-20 min, brain temperature varied significantly more than did carotid blood temperature. We attribute part of the variability in brain temperature to transient stress responses and the influence of sympathetic activation attenuating selective brain cooling. We conclude that, contrary to the widely cited postulate, the carotid rete does not protect the brain during hyperthermia. Oryx also do not show adaptive heterothermy and, over short time intervals, have a brain temperature more variable than carotid blood temperature.
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Golash A, Mitchell G, Mallucci C, May P, Pilling D. Prenatal diagnosis of suprasellar arachnoid cyst and postnatal endoscopic treatment. Childs Nerv Syst 2001; 17:739-42. [PMID: 11862440 DOI: 10.1007/s003810100467] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2000] [Revised: 03/01/2001] [Indexed: 11/25/2022]
Abstract
Arachnoid cysts are benign developmental anomalies that occur in the cerebrospinal axis in relation to the arachnoid membrane. An antenatal ultrasound scan first raises the suspicion of arachnoid cysts, but misdiagnoses have been reported. Confirmatory antenatal magnetic resonance imaging (MRI) is very useful to delineate anatomical detail and help in correct diagnosis. This helps proper counselling and treatment planning. Controversy also surrounds the surgical management, in terms of both the indications and the procedures employed. We report the successful endoscopic treatment, in a neonate, of an arachnoid cyst diagnosed by antenatal ultrasound and MRI. In this case accurate diagnosis and detailed assessment led to objective counselling and helped to optimise neonatal management.
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Mitchell G. Skin flaps. AUSTRALIAN FAMILY PHYSICIAN 2001; 30:1067-8. [PMID: 11759459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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124
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Levy E, Ménard D, Delvin E, Stan S, Mitchell G, Lambert M, Ziv E, Feoli-Fonseca JC, Seidman E. The polymorphism at codon 54 of the FABP2 gene increases fat absorption in human intestinal explants. J Biol Chem 2001; 276:39679-84. [PMID: 11487582 DOI: 10.1074/jbc.m105713200] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Based on titration microcalorimetry and Caco-2 cell line transfection studies, it has been suggested that the A54T of the FABP2 gene plays a significant role in the assimilation of dietary fatty acids. However, reports were divergent with regard to the in vivo interaction between this polymorphism and postprandial lipemia. We therefore determined the influence of this intestinal fatty acid-binding protein polymorphism on intestinal fat transport using the human jejunal organ culture model, thus avoiding the interference of various circulating factors capable of metabolizing in vivo postprandial lipids. Analysis of DNA samples from 32 fetal intestines revealed 22 homozygotes for the wild-type Ala-54/Ala-54 genotype (0.83) and 10 heterozygotes for the polymorphic Thr-54/Ala-54 genotype (0.17). The Thr-encoding allele was associated with increased secretion of newly esterified triglycerides, augmented de novo apolipoprotein B synthesis, and elevated chylomicron output. On the other hand, no alterations were found in very low density lipoprotein and high density lipoprotein production, apolipoprotein A-I biogenesis, or microsomal triglyceride transfer protein mass and activity. Similarly, the alanine to threonine substitution at residue 54 did not result in changes in brush border hydrolytic activities (sucrase, glucoamylase, lactase, and alkaline phosphatase) or in glucose uptake or oxidation. Our data clearly document that the A54T polymorphism of FABP2 specifically influences small intestinal lipid absorption without modifying glucose uptake or metabolism. It is proposed that, in the absence of confounding factors such as environmental and genetic variables, the FABP2 polymorphism has an important effect on postprandial lipids in vivo, potentially influencing plasma levels of lipids and atherogenesis.
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Domanski M, Norman J, Wolz M, Mitchell G, Pfeffer M. Cardiovascular risk assessment using pulse pressure in the first national health and nutrition examination survey (NHANES I). Hypertension 2001; 38:793-7. [PMID: 11641288 DOI: 10.1161/hy1001.092966] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Increased stiffness of the conduit arteries has been associated with increased risk of death and cardiovascular death in a number of populations. None of these populations, however, are fully representative of the US population. The cohort examined in the First National Health and Nutrition Examination Survey (NHANES I) that was free of overt cardiovascular disease was selected to be representative of the US population. We assessed and quantified the increased risk of death associated with elevated pulse pressure in this population. A cohort of 5771 subjects from NHANES I was used to determine the value of adding pulse pressure to standard cardiovascular disease risk factors for assessment of the risk of death during a mean follow-up period of 16.5 years. Analyses were performed by use of the SUDAAN statistical package for performing Cox proportional regression, logistic regression, and other standard methods in complex, weighted samples. Pulse pressure increased with increasing age, body mass index, cholesterol level, and mean arterial pressure. With increasing pulse pressure, the percentage of cigarette smokers decreased and the percentage of diabetics increased. Despite these associations with known risk factors, pulse pressure was independently predictive of an increased risk of death from cardiovascular disease, coronary heart disease, and all-cause mortality. It provides independent prognostic information beyond that provided by known risk factors that were evaluated in this study, including the Sixth Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure hypertension classification. A 10 mm Hg increase in pulse pressure in persons 25 to 45 of age was associated with a 26% increase in risk of cardiovascular death (95% confidence interval [CI], 5 to 50) and with an 10% increase (95% CI, 2 to 19) in persons 46 to 77 years of age. In a cohort designed to be representative of the US population, elevated pulse pressure has been shown to provide independent prognostic information. This variable may be a marker for the extent of vascular disease and may contribute to the occurrence of clinical events.
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