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1.
Bone Joint Res ; 6(8): 499-505, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28851694

RESUMEN

OBJECTIVES: We have increased the dose of tranexamic acid (TXA) in our enhanced total joint recovery protocol at our institution from 15 mg/kg to 30 mg/kg (maximum 2.5 g) as a single, intravenous (IV) dose. We report the clinical effect of this dosage change. METHODS: We retrospectively compared two cohorts of consecutive patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA) surgery in our unit between 2008 and 2013. One group received IV TXA 15 mg/kg, maximum 1.2 g, and the other 30 mg/kg, maximum 2.5 g as a single pre-operative dose. The primary outcome for this study was the requirement for blood transfusion within 30 days of surgery. Secondary measures included length of hospital stay, critical care requirements, re-admission rate, medical complications and mortality rates. RESULTS: A total of 1914 THA and 2537 TKA procedures were evaluated. In THA, the higher dose of TXA was associated with a significant reduction in transfusion (p = 0.02, risk ratio (RR) 0.74, 95% confidence interval (CI) 0.58 to 0.96) and rate of re-admission (p < 0.001, RR 0.50, 95% CI 0.35 to 0.71). There were reductions in the requirement for critical care (p = 0.06, RR 0.55, 95% CI 0.31 to 1.00), and in the length of stay from 4.7 to 4.3 days (p = 0.02). In TKA, transfusion requirements (p = 0.049, RR 0.64, 95% CI 0.41 to 0.99), re-admission rate (p = 0.001, RR 0.56, 95% CI 0.39 to 0.80) and critical care requirements (p < 0.003, RR 0.34, 95% CI 0.16 to 0.72) were reduced with the higher dose. Mean length of stay reduced from 4.6 days to 3.6 days (p < 0.01). There was no difference in the incidence of deep vein thrombosis, pulmonary embolism, gastrointestinal bleed, myocardial infarction, stroke or death in THA and TKA between cohorts. CONCLUSION: We suggest that a single pre-operative dose of TXA, 30 mg/kg, maximum 2.5g, results in a lower transfusion requirement compared with a lower dose in patients undergoing elective primary hip and knee arthroplasty. However, these findings should be interpreted in the context of the retrospective non-randomised study design.Cite this article: R. J. M. Morrison, B. Tsang, W. Fishley, I. Harper, J. C. Joseph, M. R. Reed. Dose optimisation of intravenous tranexamic acid for elective hip and knee arthroplasty: The effectiveness of a single pre-operative dose. Bone Joint Res 2017;6:499-505. DOI: 10.1302/2046-3758.68.BJR-2017-0005.R1.

2.
Anaesthesia ; 70(4): 462-6, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25495523

RESUMEN

We performed a prospective, randomised study to evaluate the echogenicity of 11 regional block needles when inserted into a gel phantom at 45° in the ultrasound plane. Two hundred anaesthetists viewed in random sequence recordings of each needle as it was advanced into the phantom. Participants scored the needle for echogenicity on a scale of 0-10 and categorised the needle as 'hyperechoic' or 'standard'. The mean (95% CI) echogenicity score was 1.7 (1.4-2.0) units higher for three needles marketed as 'hyperechoic' compared with standard needles marketed by the same companies, p < 0.001. The odds ratios (95% CI) that an anaesthetist would categorise a needle as hyperechoic were: 5.3 (3.6-8.0) if the needle was marketed as hyperechoic, p < 0.001; and 1.7 (1.1-2.6) if regional anaesthetic experience was ≥ 1 year compared with < 1 year, p = 0.025.


Asunto(s)
Agujas , Bloqueo Nervioso/instrumentación , Ultrasonografía Intervencional/métodos , Diseño de Equipo , Humanos , Bloqueo Nervioso/métodos , Fantasmas de Imagen , Estudios Prospectivos
3.
Cell Death Differ ; 21(6): 876-87, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24488096

RESUMEN

Cytotoxic lymphocytes (CLs) contain lysosome-related organelles (LROs) that perform the normal degradative functions of the lysosome, in addition to storage and release of powerful cytotoxins employed to kill virally infected or abnormal cells. Among these cytotoxins is granzyme B (GrB), a protease that has also been implicated in activation (restimulation)-induced cell death of natural killer (NK) and T cells, but the underlying mechanism and its regulation are unclear. Here we show that restimulation of previously activated human or mouse lymphocytes induces lysosomal membrane permeabilisation (LMP), followed by GrB release from LROs into the CL cytosol. The model lysosomal stressors sphingosine and Leu-Leu-methyl-ester, and CLs from gene-targeted mice were used to show that LMP releases GrB in both a time- and concentration-dependent manner, and that the liberated GrB is responsible for cell death. The endogenous GrB inhibitor Serpinb9 (Sb9) protects CLs against LMP-induced death but is decreasingly effective as the extent of LMP increases. We also used these model stressors to show that GrB is the major effector of LMP-mediated death in T cells, but that in NK cells additional effectors are released, making GrB redundant. We found that limited LMP and GrB release occurs constitutively in proliferating lymphocytes and in NK cells engaged with targets in vitro. In Ectromelia virus-infected lymph nodes, working NK cells lacking Sb9 are more susceptible to GrB-mediated death. Taken together, these data show that a basal level of LMP occurs in proliferating and activated lymphocytes, and is increased on restimulation. LMP releases GrB from LROs into the lymphocyte cytoplasm and its ensuing interaction with Sb9 dictates whether or not the cell survives. The GrB-Sb9 nexus may therefore represent an additional mechanism of limiting lymphocyte lifespan and populations.


Asunto(s)
Muerte Celular/efectos de los fármacos , Granzimas/metabolismo , Serpinas/metabolismo , Estrés Fisiológico/genética , Animales , Permeabilidad de la Membrana Celular/efectos de los fármacos , Humanos , Células Asesinas Naturales/efectos de los fármacos , Linfocitos/citología , Linfocitos/efectos de los fármacos , Lisosomas/efectos de los fármacos , Lisosomas/metabolismo , Lisosomas/patología , Ratones , Esfingosina/farmacología , Estrés Fisiológico/efectos de los fármacos , Linfocitos T/efectos de los fármacos
6.
Anaesthesia ; 62(5): 456-9, 2007 May.
Artículo en Inglés | MEDLINE | ID: mdl-17448056

RESUMEN

Tracheal tube impingement is common during gum elastic bougie facilitated intubation and a 90 degrees anti-clockwise rotation of the tube usually relieves it. We detail a case where this manoeuvre failed in the presence of cricoid pressure. We investigated the effect of cricoid pressure on gum elastic bougie facilitated intubation in 120 patients randomly allocated to receive sham cricoid pressure (n = 60) or 30 N cricoid pressure (n = 60). Impingement occurred in 23/60 (38%) with sham cricoid pressure and 36/60 (60%) with 30 N cricoid pressure (p < 0.025). Only females showed an increase in impingement with cricoid pressure: 29% sham cricoid pressure vs 63% 30 N cricoid pressure, p < 0.01, whereas the impingement in males was approximately 60% in both groups. Ninety degree anti-clockwise rotation of the tube was successful in all 23 patients (100%) with sham cricoid pressure and in 32/36 patients (89%) with 30 N cricoid pressure. Releasing cricoid pressure relieved the obstruction in the four cases where 90 degrees anti-clockwise rotation of the tube failed. Impingement is common and 90 degrees anti-clockwise rotation is highly effective in both the presence and absence of cricoid pressure. In a small number of cases, cricoid pressure may cause the manoeuvre to fail.


Asunto(s)
Cartílago Cricoides , Intubación Intratraqueal/métodos , Adulto , Anciano , Anciano de 80 o más Años , Anestesia General , Anestesia Obstétrica , Femenino , Humanos , Intubación Intratraqueal/instrumentación , Masculino , Persona de Mediana Edad , Embarazo , Presión , Rotación , Factores Sexuales , Insuficiencia del Tratamiento , Resultado del Tratamiento
7.
Int J Obes Relat Metab Disord ; 27(12): 1578-83, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12975636

RESUMEN

BACKGROUND: Obesity results from a chronic imbalance between energy intake and energy expenditure. However, experimental evidence of the relative contribution of interindividual differences in energy intake and expenditure (resting or due to physical activity) to weight gain is limited. OBJECTIVE: To assess prospectively the association between baseline measurements of daily energy metabolism and weight changes by studying free-living adult Pima Indians, one of the most obese populations in the world. DESIGN: A study of the pathogenesis of obesity in the Pima Indians living in Southwestern Arizona. The participants were 92 nondiabetic Pima Indians (64M/28F, 35+/-12 y, 35+/-9% body fat; mean+/-s.d.). At baseline, free-living daily energy metabolism was assessed by doubly labeled water and resting metabolic rate (RMR) by indirect calorimetry. Data on changes in body weight (5.8+/-6.5 kg) over a follow-up period of 4+/-3 y were available in 74 (49M/25F) of the 92 subjects. RESULTS: The baseline calculated total energy intake (r=0.25, P=0.028) and RMR (r=-0.28, P=0.016) were significantly associated with changes in body weight. The baseline energy expenditure due to physical activity was not associated with changes in body weight. CONCLUSION: Using state-of-the-art methods to assess energy intake and expenditure in free-living conditions, we show for the first time that the baseline calculated total energy intake is a determinant of changes in body weight in Pima Indians. These data also confirm that a low RMR is a risk factor for weight gain in this population.


Asunto(s)
Metabolismo Basal/fisiología , Ingestión de Energía/fisiología , Indígenas Norteamericanos , Obesidad/fisiopatología , Aumento de Peso/fisiología , Adulto , Arizona , Calorimetría Indirecta/métodos , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Obesidad/etnología , Estudios Prospectivos
8.
J Microsc ; 204(Pt 2): 108-18, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11737544

RESUMEN

The difficulties traditionally faced by functional morphologists in representing and interpreting three-dimensional objects can now be mostly overcome using available laser and computer imaging technologies. A practical method for three-dimensional imaging of small mammalian teeth using confocal microscopy is reported. Moulding and casting of the teeth were first performed, followed by confocal fluorescence imaging. Accuracy and precision of the scanned structures were tested in morphometric studies by using a new technique to measure the noise in the scan of a three-dimensional surface, and linear and angular dimensions of the scans were compared with measurements made using traditional morphological tools. It is shown that measurements can be taken with less than 4% difference from the original object. Teeth of the microchiropteran bat Chalinolobus gouldii were scanned and measured to show the potential of the techniques. Methods for visualizing the small teeth in three-dimensional space, and animating the teeth in occlusion, show the power of this approach in aiding a three-dimensional understanding of the structure and function of teeth and other three-dimensional structures.


Asunto(s)
Microscopía Confocal/métodos , Diente/anatomía & histología , Animales , Pesos y Medidas Corporales , Quirópteros , Imagenología Tridimensional
9.
Diabetes ; 50(4): 901-4, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11289060

RESUMEN

Brain dopaminergic pathways play a major role in the control of movement. Absence of the murine dopamine D2 receptor gene (drd2) produces bradykinesia and hypothermia. A Ser311Cys mutation of the human DRD2 produces a marked functional impairment of the receptor and is associated with higher BMI in some populations. We hypothesized that the Ser311Cys mutation of DRD2 may inhibit energy expenditure. Here we report that total energy expenditure (doubly labeled water) measured in 89 nondiabetic Pima Indians was 244 kcal/ day lower in homozygotes for the Cys311-encoding allele when compared with those heterozygous and homozygous for the Ser311-encoding allele (P = 0.056). The 24-h resting energy expenditure (respiratory chamber) measured in 320 nondiabetic Pimas was also 87 kcal/day lower in homozygotes for the Cys311-encoding allele when compared with those heterozygous and homozygous for the Ser311-encoding allele (P = 0.026). These findings are the first evidence that a genetic mutation is associated with reduced energy expenditure in humans. Because the impact of this mutation on human obesity is small, we suggest that either the energy deficit induced is not large enough to significantly influence body weight in this population and/or that the Cys311-encoding allele is also associated with reduced energy intake.


Asunto(s)
Metabolismo Energético/genética , Mutación/genética , Mutación/fisiología , Receptores de Dopamina D2/genética , Adulto , Alelos , Secuencia de Aminoácidos/genética , Femenino , Heterocigoto , Homocigoto , Humanos , Indígenas Norteamericanos/genética , Masculino , Valores de Referencia
10.
J Appl Physiol (1985) ; 90(3): 1007-12, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11181612

RESUMEN

The purpose of this study was to compare substrate utilization during fasting and submaximal exercise in morbidly obese women after weight loss (WL) with that in weight-matched controls (C). WL were studied in the weight-stable condition approximately 24 mo after gastric bypass surgery. Energy intake (self-reported) and expenditure ((2)H(2)(18)O) were also compared. The respiratory exchange ratio during exercise at the same absolute (15 W) workload was significantly (P < or = 0.05) elevated in WL vs. C (0.90 +/- 0.02 vs. 0.83 +/- 0.03); this was reflected as lower fat utilization in WL (29.7 +/- 4.8 vs. 53.2 +/- 9.7% of energy from fat). Respiratory exchange ratio during exercise at the same relative (65% of maximal O(2) uptake) intensity was also significantly (P < 0.05) elevated in WL (0.96 +/- 0.01 vs. 0.89 +/- 0.02), and fat use was concomitantly depressed (12.4 +/- 3.0 vs. 34.3 +/- 9.9% of energy from fat). Resting substrate utilization, daily energy expenditure, and self-reported relative macronutrient intake did not differ between groups. These data suggest that lipid oxidation is depressed during physical activity in WL. This defect may, at least in part, contribute to a propensity for the development of morbid obesity.


Asunto(s)
Metabolismo Energético , Ejercicio Físico/fisiología , Obesidad Mórbida/fisiopatología , Consumo de Oxígeno/fisiología , Esfuerzo Físico/fisiología , Pérdida de Peso/fisiología , Adulto , Índice de Masa Corporal , Peso Corporal , Deuterio , Ingestión de Energía , Ayuno/fisiología , Femenino , Frecuencia Cardíaca , Humanos , Obesidad Mórbida/cirugía , Isótopos de Oxígeno , Valores de Referencia , Mecánica Respiratoria
11.
J Mol Cell Cardiol ; 33(2): 343-57, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11162138

RESUMEN

OBJECTIVES: Melatonin, a hormonal product of the pineal gland, is now known to be a multi-faceted free radical scavenger and anti-oxidant. Since little information is available regarding the action of melatonin on the heart, we studied the effects of melatonin on adult ventricular myocytes subjected to chemical hypoxia and reoxygenation. METHODS: Adult rat ventricular myocytes were preloaded with tetramethylrhodamine (TMRM) in combination with one of the following fluorophores: dichlorodihydrofluorescein diacetate (DCDHF), dihydrorhodamine 123 (DHR) or fluo 3 (Fluo) and then investigated with confocal laser scanning microscopy. Chemical hypoxia was induced by addition of 1.5 mM KCN and 20 mM deoxyglucose to the superfusion buffer. Melatonin (50-100 microM) was added at intervals during the protocol. RESULTS: Cells subjected to 12.5 min chemical hypoxia showed marked morphological changes, increased fluorescence intensity of DCDHF, DHR and Fluo, suggesting Ca2+ accumulation and generation of H2O2 and reactive oxygen species. The number of cells showing increased fluorescence also increased significantly. Melatonin (50 and 100 microM) caused a significant reduction in morphological changes, number of cells with increased fluorescence and fluorescence intensity of DHR and Fluo, (but not DCDHF). CONCLUSION: Melatonin effectively reduced damage induced by chemical hypoxia in adult cardiomyocytes, probably by virtue of its effects on reactive oxygen species generation and intracellular Ca2+ accumulation.


Asunto(s)
Melatonina/uso terapéutico , Miocardio/metabolismo , Daño por Reperfusión/prevención & control , Compuestos de Anilina/farmacología , Animales , Calcio/metabolismo , Células Cultivadas , Fluoresceínas/farmacología , Colorantes Fluorescentes/farmacología , Ventrículos Cardíacos/efectos de los fármacos , Hipoxia , Procesamiento de Imagen Asistido por Computador , Masculino , Microscopía Confocal , Miocardio/citología , Perfusión , Ratas , Rodaminas/farmacología , Factores de Tiempo , Xantenos/farmacología
12.
Blood ; 96(10): 3480-9, 2000 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-11071645

RESUMEN

Shear-induced binding of von Willebrand factor (vWf) to the platelet glycoprotein (GP) Ib/V/IX complex plays a key role in initiating platelet adhesion and aggregation at sites of vascular injury. This study demonstrated that pretreating human platelets with inhibitors of actin polymerization, cytochalasin D or latrunculin B, dramatically enhances platelet aggregation induced by vWf. The effects of these inhibitors were specific to the vWf-GPIbalpha interaction because they enhanced vWf-induced aggregation of Glanzmann thrombasthenic platelets and Chinese hamster ovary (CHO) cells transfected with GPIb/V/IX. Moreover, cytochalasin D enhanced the extent of platelet aggregation induced by high shear stress (5000 s(-1)) and also lowered the shear threshold required to induce aggregation from 3000 s(-1) to as low as 500 s(-1). Studies of CHO cells expressing GPIbalpha cytoplasmic tail truncation mutants that failed to bind actin-binding protein-280 (deletion of residues 569-610 or 535-568) demonstrated that the linkage between GPIb and actin-binding protein-280 was not required for vWf-induced actin polymerization, but was critical for the enhancing effects of cytochalasin D on vWf-induced cell aggregation. Taken together, these studies suggest a fundamentally important role for the cytoskeleton in regulating the adhesive function of GPIb/V/IX.


Asunto(s)
Citoesqueleto/fisiología , Depsipéptidos , Complejo GPIb-IX de Glicoproteína Plaquetaria/metabolismo , Factor de von Willebrand/metabolismo , Citoesqueleto de Actina/efectos de los fármacos , Citoesqueleto de Actina/fisiología , Actinas/antagonistas & inhibidores , Actinas/metabolismo , Actinas/ultraestructura , Adenosina Difosfato/farmacología , Alprostadil/farmacología , Animales , Anticuerpos Monoclonales , Plaquetas/efectos de los fármacos , Plaquetas/metabolismo , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Células CHO/efectos de los fármacos , Células CHO/metabolismo , Células CHO/fisiología , Cricetinae , Citocalasina D/farmacología , Citoesqueleto/metabolismo , Humanos , Mutagénesis Sitio-Dirigida/fisiología , Péptidos Cíclicos/efectos de los fármacos , Agregación Plaquetaria/efectos de los fármacos , Inhibidores de Agregación Plaquetaria/farmacología , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/inmunología , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/metabolismo , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/farmacología , Complejo GPIb-IX de Glicoproteína Plaquetaria/genética , Estrés Mecánico , Tiazoles/farmacología , Tiazolidinas , Trombastenia/metabolismo , Trombastenia/patología , Trombastenia/fisiopatología , Transfección , Factor de von Willebrand/efectos de los fármacos
13.
Am J Clin Nutr ; 72(4): 946-53, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11010936

RESUMEN

BACKGROUND: An adaptive decrease in energy expenditure (EE) in response to 6 mo of severely restricted energy intake was shown in a classic semistarvation study-the Minnesota experiment. OBJECTIVE: Our objective was to examine whether such adaptation also occurs in response to less severe but sustained energy restriction. DESIGN: Body composition, 1-wk total EE (TEE), 24-h sedentary EE, and spontaneous physical activity were measured in 8 healthy subjects (4 men and 4 women) at the end of a 2-y confinement inside Biosphere 2. Unexpectedly, the food supply was markedly restricted during most of the confinement and all subjects experienced a marked, sustained weight loss (9.1 +/- 6.6 kg; P: < 0.001) from the low-energy (7000-11000 kJ/d), low-fat (9% of energy), but nutrient-dense, diet they consumed. RESULTS: The TEE inside Biosphere 2, assessed 3 wk before exit, averaged 10700 +/- 560 kJ/d (n = 8). Within 1 wk after exit, the adjusted 24-h EE and spontaneous physical activity were lower in the biospherians (n = 5) than in 152 control subjects (6% and 45%, respectively; both P: < 0.01). Six months after exit and return to an ad libitum diet, body weight had increased to preentry levels; however, adjusted 24-h EE and spontaneous physical activity were still significantly lower than in control subjects. CONCLUSIONS: In lean humans, an adaptive decrease in EE appears to occur not only in states of life-threatening undernutrition, but also in response to less severe energy restriction sustained over several years.


Asunto(s)
Dieta , Ingestión de Energía/fisiología , Metabolismo Energético/fisiología , Adulto , Anciano , Metabolismo Basal , Composición Corporal , Calorimetría Indirecta , Sistemas Ecológicos Cerrados , Ejercicio Físico/fisiología , Femenino , Humanos , Modelos Lineales , Masculino , Consumo de Oxígeno , Radioinmunoensayo , Análisis de Regresión , Tirotropina/sangre , Tiroxina/sangre , Triyodotironina/sangre , Pérdida de Peso
14.
J Clin Invest ; 105(6): 783-91, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10727447

RESUMEN

In this study we have examined the mechanism of platelet aggregation under physiological flow conditions using an in vitro flow-based platelet aggregation assay and an in vivo rat thrombosis model. Our studies demonstrate an unexpected complexity to the platelet aggregation process in which platelets in flowing blood continuously tether, translocate, and/or detach from the luminal surface of a growing platelet thrombus at both arterial and venous shear rates. Studies of platelets congenitally deficient in von Willebrand factor (vWf) or integrin alpha(IIb)beta(3) demonstrated a key role for platelet vWf in mediating platelet tethering and translocation, whereas integrin alpha(IIb)beta(3) mediated cell arrest. Platelet aggregation under flow appears to be a multistep process involving: (a) exposure of vWf on the surface of immobilized platelets; (b) a reversible phase of platelet aggregation mediated by the binding of GPIbalpha on the surface of free-flowing platelets to vWf on the surface of immobilized platelets; and (c) an irreversible phase of aggregation dependent on integrin alpha(IIb)beta(3). Studies of platelet thrombus formation in vivo demonstrate that this multistep adhesion mechanism is indispensable for platelet aggregation in arterioles and also appears to promote platelet aggregate formation in venules. Together, our studies demonstrate an important role for platelet vWf in initiating the platelet aggregation process under flow and challenge the currently accepted view that the vWf-GPIbalpha interaction is exclusively involved in initiating platelet aggregation at elevated shear rates.


Asunto(s)
Modelos Biológicos , Agregación Plaquetaria/fisiología , Factor de von Willebrand/fisiología , Animales , Células CHO , Cricetinae , Cricetulus , Hemorreología , Humanos , Adhesividad Plaquetaria/fisiología , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/fisiología , Complejo GPIb-IX de Glicoproteína Plaquetaria/genética , Complejo GPIb-IX de Glicoproteína Plaquetaria/fisiología , Ratas , Trombastenia/sangre , Trombosis/etiología , Trombosis/fisiopatología , Transfección , Enfermedades de von Willebrand/sangre
15.
Int J Obes Relat Metab Disord ; 24(1): 55-9, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10702751

RESUMEN

BACKGROUND: Obesity is caused by an imbalance between energy intake and energy expenditure. However, it is unknown whether increased physical activity protects susceptible populations against the development of obesity and type 2 diabetes. OBJECTIVE: To investigate the potential protective role of environment and physical activity against obesity by measuring total energy expenditure in Mexican and USA Pima Indians. METHODS: We compared the physical activity level of 40 (17 female and 23 male; 37+/-11 y, 66+/-13 kg) Mexican Pima Indians from a remote, mountainous area of Northwest Mexico, with 40 age-and-sex matched (17 female and 23 male; 37+/-12 y, 93+/-22 kg) Pima Indians from the Gila River Indian Community in Arizona, USA. We measured total energy expenditure (TEE) by doubly labeled water and calculated physical activity by different methods: physical activity level (PAL) as the ratio of TEE on resting metabolic rate (RMR), TEE adjusted for RMR by linear regression, activity energy expenditure adjusted for body weight (AEE), and activity questionnaire. RESULTS: Physical activity was higher in Mexican Pima Indians when compared with USA Pima Indians as assessed by PAL (1.97+/-0.34 vs 1.57+/-0.16, P<0.0001), TEE adjusted for RMR (3289+/-454 vs 2671+/-454 kcal/day, P<0.0001) and AEE adjusted for body weight (1243+/-415 vs 711+/-415 kcal/day, P<0. 0001). Questionnaires revealed more time spent on occupational activities among Mexican Pima compared with USA Pima (23.9+/-13.3 vs 12.6+/-13.9 h/week, P<0.001). CONCLUSION: These data support a significant role for physical activity in the prevention of obesity in genetically susceptible populations. International Journal of Obesity (2000)24, 55-59


Asunto(s)
Pueblo Asiatico/genética , Diabetes Mellitus Tipo 2/epidemiología , Metabolismo Energético/genética , Indígenas Norteamericanos/genética , Obesidad/epidemiología , Adulto , Arizona/epidemiología , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/prevención & control , Ejercicio Físico , Femenino , Humanos , Modelos Lineales , Masculino , México/epidemiología , Obesidad/genética , Obesidad/prevención & control , Encuestas y Cuestionarios
16.
J Appl Physiol (1985) ; 88(3): 944-56, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10710390

RESUMEN

The maintenance of body cell mass (BCM) is critical for survival in human immunodeficiency virus (HIV) infection. Accuracy of bioimpedance for measuring change (Delta) in intracellular water (ICW), which defines BCM, is uncertain. To evaluate bioimpedance-estimated DeltaBCM, the ICW of 21 weight-losing HIV patients was measured before and after anabolic steroid therapy by dilution (total body water by deuterium - extracellular water by bromide) and bioimpedance. Multiple-frequency modeling- and dilution-determined DeltaICW did not differ. The DeltaICW was predicted poorly by 50-kHz parallel reactance, 50-kHz impedance, and 200 - 5-kHz impedance. The DeltaICW predicted by 500 - 5-kHz impedance was closer to, but statistically different from, dilution-determined DeltaICW. However, the effect of random error on the measurement of systematic error in the 500 - 5-kHz method was 12-13% of the average measured DeltaICW; this was nearly twice the percent difference between obtained and threshold statistics. Although the 500 - 5-kHz method cannot be fully rejected, these results support the conclusion that only the multiple-frequency modeling approach accurately monitors DeltaBCM in HIV infection.


Asunto(s)
Impedancia Eléctrica , Infecciones por VIH/patología , Adulto , Anabolizantes/uso terapéutico , Agua Corporal/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Estudios de Evaluación como Asunto , Espacio Extracelular/efectos de los fármacos , Femenino , Infecciones por VIH/tratamiento farmacológico , Humanos , Líquido Intracelular/efectos de los fármacos , Masculino , Métodos , Persona de Mediana Edad , Oxandrolona/uso terapéutico , Pérdida de Peso/efectos de los fármacos
17.
J Biol Chem ; 274(51): 36241-51, 1999 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-10593912

RESUMEN

Platelet adhesion to sites of vascular injury is initiated by the binding of the platelet glycoprotein (GP) Ib-V-IX complex to matrix-bound von Willebrand factor (vWf). This receptor-ligand interaction is characterized by a rapid on-off rate that enables efficient platelet tethering and rolling under conditions of rapid blood flow. We demonstrate here that platelets adhering to immobilized vWf under flow conditions undergo rapid morphological conversion from flat discs to spiny spheres during surface translocation. Studies of Glanzmann thrombasthenic platelets (lacking integrin alpha(IIb)beta(3)) and Chinese hamster ovary (CHO) cells transfected with GPIb/IX (CHO-Ib/IX) confirmed that vWf binding to GPIb/IX was sufficient to induce actin polymerization and cytoskeletal reorganization independent of integrin alpha(IIb)beta(3). vWf-induced cytoskeletal reorganization occurred independently of several well characterized signaling processes linked to platelet activation, including calcium influx, prostaglandin metabolism, protein tyrosine phosphorylation, activation of protein kinase C or phosphatidylinositol 3-kinase but was critically dependent on the mobilization of intracellular calcium. Studies of Oregon Green 488 1, 2-bis(o-amino-5-fluorophenoxy)ethane-N,N,N',N-tetraacetic acid tetraacetoxymethyl ester-loaded platelets and CHO-Ib/IX cells demonstrated that these cells mobilize intracellular calcium in a shear-dependent manner during surface translocation on vWf. Taken together, these studies suggest that the vWf-GPIb interaction stimulates actin polymerization and cytoskeletal reorganization in rolling platelets via a shear-sensitive signaling pathway linked to intracellular calcium mobilization.


Asunto(s)
Citoesqueleto/fisiología , Agregación Plaquetaria/fisiología , Complejo GPIb-IX de Glicoproteína Plaquetaria/fisiología , Factor de von Willebrand/fisiología , Actinas/química , Actinas/fisiología , Animales , Plaquetas/fisiología , Plaquetas/ultraestructura , Células CHO , Cricetinae , Dimerización , Complejo GPIb-IX de Glicoproteína Plaquetaria/química , Transfección , Factor de von Willebrand/química
18.
Anaesth Intensive Care ; 26(4): 366-70, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9743849

RESUMEN

The anti-nauseant efficacy of low-dose propofol was investigated in a blinded, randomized trial. Patients who complained of nausea and/or vomiting following laparoscopic gynaecological surgery and who requested antiemetic were randomly assigned to receive placebo, propofol 3 mg, propofol 9 mg or propofol 27 mg by intravenous injection. Nausea, vomiting and sedation were recorded by a blinded observer for 90 minutes following administration of the test drug, prior to discharge, and 24 hours following surgery. Rescue antiemetic (droperidol 1.0 mg i.v.) was available from 10 minutes after administration of test drug. Propofol failed to reduce nausea scores and did not reduce the incidence of vomiting. Numbers of patients receiving rescue antiemetic were similar in the four treatment groups. In the first 10 minutes following test drug administration, sedation scores were increased by propofol in a dose-related manner. We conclude that, in the dose range studied, propofol is ineffective for the treatment of nausea and vomiting occurring soon after laparoscopic gynaecological surgery.


Asunto(s)
Antieméticos/uso terapéutico , Náusea y Vómito Posoperatorios/tratamiento farmacológico , Propofol/uso terapéutico , Adulto , Femenino , Procedimientos Quirúrgicos Ginecológicos , Humanos , Inyecciones Intravenosas , Laparoscopía , Persona de Mediana Edad , Método Simple Ciego , Resultado del Tratamiento
19.
J Bioenerg Biomembr ; 30(3): 207-22, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9733088

RESUMEN

Using laser scanning confocal microscopy, our objective was to measure mitochondrial, nuclear, and cytosolic free ionized Ca2+ in adult rabbit cardiac myocytes loaded with Ca2+-indicating fluorophores. When myocytes were loaded with Fluo 3 at 37 degrees C, the fluorophore was loaded extensively into the cytosol and nucleus, but poorly into mitochondria, and Fluo 3 fluorescence transients after field stimulation were confined to the cytosol and nucleus. In contrast, after loading at 4 degrees C, Fluo 3 also entered mitochondria, and large transients of mitochondrial Fluo 3 fluorescence then occurred after stimulation. Isoproterenol (1 microM) increased the magnitude of Ca2+ transients and their subsequent rate of decay, an effect more marked in the cytosol and nucleus than in mitochondria. As pacing frequency was increased from 0.5 to 2 Hz, diastolic mitochondrial Ca2+ rose markedly in the absence but not in the presence of isoproterenol. Resting Ca2+ estimated by Indo 1 ratio imaging using UV/visible laser scanning confocal microscopy was about 200 nM in all compartments. During field stimulation, Ca2+ transiently increased to 671, 522, and 487 nM in cytosol, interfibrillar mitochondria, and perinuclear mitochondria, respectively. Isoproterenol increased these respective peak values to 1280, 750, and 573 nM. These results were consistent with those obtained in Fluo 3 experiments. We conclude that rapid mitochondrial Ca2+ transients occur during excitation-contraction coupling in adult rabbit cardiac myocytes, which may be important in matching mitochondrial metabolism to myocardial ATP demand during changes in cardiac output.


Asunto(s)
Calcio/metabolismo , Mitocondrias Cardíacas/metabolismo , Contracción Miocárdica , Miocardio/metabolismo , Compuestos de Anilina , Animales , Colorantes Fluorescentes , Indoles , Isoproterenol/farmacología , Miocardio/citología , Conejos , Temperatura , Xantenos
20.
Int J STD AIDS ; 9(7): 418-23, 1998 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9696199

RESUMEN

Samraksha, a non-governmental organization (NGO) in Bangalore, South India, was established in 1993 to take steps to control the spread of HIV infection. As a result of their interactions the Samraksha team recognized the urgent need for management of sexually transmitted diseases (STDs) as a crucial component of their work. Samraksha approached Action Health, a UK-based charity, for assistance. This paper outlines the needs assessment and the process of setting up a Well Woman Clinic for commercial sex workers (CSWs) and other vulnerable groups in Bangalore. The pilot project has been running for over a year and has gained credibility both with vulnerable women and with professionals. Furthermore it has officially become a government resource centre for the training of doctors and health-care staff in the management of STDs, and provides formal training sessions for the staff at each of the primary health-care centres in Bangalore. Thus STD management is being integrated with the current primary health-care provision for women throughout Bangalore. Factors influencing the successful development of such a service are considered.


Asunto(s)
Instituciones de Atención Ambulatoria , Infecciones por VIH/prevención & control , Servicios Preventivos de Salud , Instituciones de Atención Ambulatoria/economía , Costos y Análisis de Costo , Femenino , Infecciones por VIH/transmisión , Humanos , India , Proyectos Piloto , Servicios Preventivos de Salud/economía , Trabajo Sexual , Salud de la Mujer
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