Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
J Dairy Sci ; 104(8): 8673-8684, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33934867

RESUMEN

We evaluated the effects of fatty acid (FA) supplement blends containing 60% palmitic acid (C16:0) and either 30% stearic acid (C18:0) or 30% oleic acid (cis-9 C18:1) on nutrient digestibility and milk production of low- and high-producing dairy cows. Twenty-four multiparous Holstein cows [118 ± 44 d in milk (DIM)] were divided into 2 blocks by milk production and then randomly assigned to treatment sequence in four 3 × 3 Latin squares within production level, balanced for carryover effects in three consecutive 21-d periods. Cows were blocked by milk yield and assigned to 1 of 2 groups (n = 12 per group): (a) low group (42.5 ± 3.54 kg/d; 147 ± 42 DIM) and (b) high group (55.8 ± 3.04 kg/d; 101 ± 34 DIM). Commercially available fat supplements were combined to provide treatments that consisted of the following: (1) control (CON; diet with no supplemental FA), (2) FA supplement blend containing 60% C16:0 and 30% C18:0 (PA+SA), and (3) FA supplement blend containing 60% C16:0 and 30% cis-9 C18:1 (PA+OA) The FA blends were fed at 1.5% of dry matter (DM) and replaced soyhulls from CON. Preplanned contrasts were (1) overall effect of FA treatments [CON vs. the average of the FA treatments (FAT); 1/2 (PA+SA + PA+OA)], and (2) effect of FA supplement (PA+SA vs. PA+OA). Regardless of production level, overall FAT reduced DMI compared with CON. Also, regardless of level of milk production, PA+OA increased total-tract FA digestibility compared with PA+SA. Treatment by production level interactions were observed for neutral detergent fiber (NDF) digestibility, total FA intake, and the yields of 3.5% fat-corrected milk (FCM), energy-corrected milk (ECM), and milk fat. In low-producing cows, FAT increased DM and NDF digestibility compared with CON. In high-producing cows PA+SA increased DM and NDF digestibility compared with PA+OA. In low-producing cows, PA+SA increased 3.5% FCM, ECM, and milk fat yield compared with PA+OA. However, in high-producing cows PA+OA tended to increase 3.5% FCM compared with PA+SA. In conclusion, low-producing cows responded better to a FA blend containing 60% C16:0 and 30% C18:0, whereas high-producing dairy cows responded more favorably to a FA blend containing 60% C16:0 and 30% cis-9 C18:1. However, further research is required to validate our observations that higher-yielding cows have improved production responses when supplemented with cis-9 C18:1 compared with C18:0.


Asunto(s)
Leche , Ácido Palmítico , Alimentación Animal/análisis , Animales , Bovinos , Dieta/veterinaria , Suplementos Dietéticos , Digestión , Ácidos Grasos , Femenino , Lactancia , Nutrientes , Ácido Oléico
2.
Intern Med J ; 43(8): 888-95, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23734916

RESUMEN

BACKGROUND: Implantable cardioverter defibrillators (ICD) have been demonstrated to reduce mortality in survivors of life-threatening arrhythmias (secondary prevention) and in patients at increased risk of sudden cardiac death (primary prevention). Other nations have reported significant increases in ICD use in recent years. AIM: To investigate Australian nationwide trends of ICD procedures over a 10-year period (2000-2009). METHODS: A retrospective analysis of the Australian Institute of Health and Welfare's National Hospital Morbidity Database was performed to determine the annual number of ICD implantation and replacement procedures between 2000 and 2009. Rates were calculated using Australian Bureau of Statistics data on the annual estimated population. Time trends in the yearly procedure number and rate were analysed using negative binomial regression models with comparisons made by age and sex. RESULTS: The number of new ICD implantations increased from 708 to 3198 procedures between 2000 and 2009. Replacement procedures increased from 290 to 1378. The implantation rate (per million) increased from 37.0 to 145.6 and the replacement rate from 15.1 to 62.7. When rates were adjusted for age and sex, the implantation rate increased annually by 15.8% and the replacement rate by 16.6% (P < 0.0001). Procedures occurred most commonly in men (implantations: 80.1%; replacements: 78.0%) between ages 70-79. CONCLUSIONS: ICD procedures increased significantly in Australia between 2000-2009. Despite these increases, other studies have suggested ICD devices are currently under-utilised. During the study period, males accounted for the majority of ICD procedures. While there are numerous reasons for this, it is not known if device under-use is more common in females.


Asunto(s)
Arritmias Cardíacas/epidemiología , Arritmias Cardíacas/terapia , Desfibriladores Implantables/estadística & datos numéricos , Desfibriladores Implantables/tendencias , Adulto , Anciano , Anciano de 80 o más Años , Australia/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
3.
Womens Health Rep (New Rochelle) ; 1(1): 232-240, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33786485

RESUMEN

Objective: To examine how measures of infertility based on medical criteria and based on self-perception relate to depressive symptoms among women with infertility. Background: Survey-based studies of depressive symptoms have used either measures of self-reported infertility based on meeting medical criteria or measures of self-perceived fertility problems, but seldom both. It is, therefore, not known which type of measure is more closely associated with depressive symptoms. Materials and Methods: Using ordinary least-squares multiple regression, this study compares associations between a measure of meeting medical criteria for infertility and a measure of self-perceived fertility problems with a common measure of depressive symptoms. Data come from the National Survey of Fertility Barriers, a population-based survey of 4,711 U.S. women. Results: Both meeting medical criteria for infertility and self-perception were associated with depressive symptoms after controlling for a number of relevant variables, but the coefficient for the self-perception measure was slightly higher than the coefficient for medical criteria. Conclusion: If possible, both medical criteria and self-perception measures should be used in studies of the consequences of infertility for psychosocial outcomes. If only one measure can be used, self-perception of a fertility problem is an acceptable measure.

4.
Science ; 247(4944): 831-3, 1990 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-2154849

RESUMEN

The complex formed in solution by native and chemically modified cytochrome c with cytochrome b5 has been studied by 1H and 13C nuclear magnetic resonance spectroscopy (NMR). Contrary to predictions of recent theoretical analysis, 1H NMR spectroscopy indicates that there is no major movement of cytochrome c residue Phe82 on binding to cytochrome b5. The greater resolution provided by 13C NMR spectroscopy permits detection of small perturbations in the environments of cytochrome c residues Ile75 and Ile85 on binding with cytochrome b5, a result that is in agreement with earlier model-building experiments. As individual cytochrome c lysyl residues are resolved in the 1H NMR spectrum of N-acetimidylated cytochrome c, the interaction of this modified protein with cytochrome b5 has been studied to evaluate the number of cytochrome c lysyl residues involved in binding to cytochrome b5. The results of this experiment indicate that at least six lysyl residues are involved, two more than predicted by static model building, which indicates that cytochrome c and cytochrome b5 form two or more structurally similar 1:1 complexes in solution.


Asunto(s)
Grupo Citocromo c/metabolismo , Citocromos b5/metabolismo , Isótopos de Carbono , Hidrógeno , Espectroscopía de Resonancia Magnética/métodos , Unión Proteica , Conformación Proteica , Propiedades de Superficie
5.
EClinicalMedicine ; 7: 39-46, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31008449

RESUMEN

BACKGROUND: Many women who are at increased risk of breast cancer due to a mother or sister diagnosed with breast cancer aged under 40 do not currently qualify for surveillance before 40 years of age. There are almost no available data to assess whether mammography screening aged 35-39 years would be effective in this group, in terms of detection of breast cancer at an early stage or cost effective. METHODS: A cohort screening study (FH02) with annual mammography was devised for women aged 35-39 to assess the sensitivity and screening performance and potential survival of women with identified tumours. FINDINGS: 2899 women were recruited from 12/2006-12/2015. These women underwent 12,086 annual screening mammograms and were followed for 13,365.8 years. A total of 55 breast cancers in 54 women occurred during the study period (one bilateral) with 50 cancers (49 women) (15 CIS) adherent to the screening. Eighty percent (28/35) of invasive cancers were ≤ 2 cm and 80% also lymph node negative. Invasive cancers diagnosed in FH02 were significantly smaller than the comparable (POSH-unscreened prospective) study group (45% (131/293) ≤ 2 cm in POSH vs 80% (28/35) in FH02 p < 0.0001), and were less likely to be lymph-node positive (54% (158/290, 3 unknown) in POSH vs 20% (7/35) in FH02: p = 0.0002. Projected and actual survival were also better than POSH. Overall radiation dose was not higher than in an older screened population at mean dose on study per standard sized breast of 1.5 mGy. INTERPRETATION: Mammography screening aged 35-39 years detects breast cancer at an early stage and is likely to be as effective in reducing mortality as in women at increased breast cancer risk aged 40-49 years.

6.
Eur J Cancer ; 43(4): 660-75, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17276672

RESUMEN

According to EUSOMA position paper 'The requirements of a specialist breast unit', each breast unit should have a core team made up of health professionals who have undergone specialist training in breast cancer. In this paper, on behalf of EUSOMA, authors have identified the standards of training in breast cancer, to harmonise and foster breast care training in Europe. The aim of this paper is to contribute to the increase in the level of care in a breast unit, as the input of qualified health professionals increases the quality of breast cancer patient care.


Asunto(s)
Neoplasias de la Mama/terapia , Educación Médica , Personal de Salud/educación , Oncología Médica/educación , Educación en Enfermería/métodos , Femenino , Cirugía General/educación , Humanos , Medicina Nuclear/educación , Radiología/educación
7.
J Mol Biol ; 286(1): 95-104, 1999 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-9931252

RESUMEN

The assembly of the viral structural proteins into infectious virions is often mediated by scaffolding proteins. These proteins are transiently associated with morphogenetic intermediates but not found in the mature particle. The genes encoding three Microviridae (phiX174, G4 and alpha3) internal scaffolding proteins (B proteins) have been cloned, expressed in vivo and assayed for the ability to complement null mutations of different Microviridae species. Despite divergence as great as 70% in amino acid sequence over the aligned length, cross-complementation was observed, indicating that these proteins are capable of directing the assembly of foreign structural proteins into infectious particles. These results suggest that the Microviridae internal scaffolding proteins may be inherently flexible. There was one condition in which a B protein could not cross-function. The phiX174 B protein cannot productively direct the assembly of the G4 capsid at temperatures above 21 degreesC. Under these conditions, assembly is arrested early in the morphogenetic pathway, before the first B protein mediated reaction. Two G4 mutants, which can productively utilize the phiX174 B protein at elevated temperatures, were isolated. Both mutations confer amino acid substitutions in the viral coat protein but differ in their relative abilities to utilize the foreign scaffolding protein. The more efficient substitution is located in a region where coat-scaffolding interactions have been observed in the atomic structure and may emphasize the importance of interactions in this region.


Asunto(s)
Microviridae/fisiología , Proteínas Virales/química , Secuencia de Aminoácidos , Bacteriófago phi X 174/genética , Bacteriófago phi X 174/fisiología , Proteínas de Unión al ADN/química , Escherichia coli/virología , Datos de Secuencia Molecular , Homología de Secuencia de Aminoácido , Proteínas Virales/fisiología , Ensamble de Virus
8.
J Mol Biol ; 288(4): 595-608, 1999 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-10329166

RESUMEN

An empty precursor particle called the procapsid is formed during assembly of the single-stranded DNA bacteriophage phiX174. Assembly of the phiX174 procapsid requires the presence of the two scaffolding proteins, D and B, which are structural components of the procapsid, but are not found in the mature virion. The X-ray crystallographic structure of a "closed" procapsid particle has been determined to 3.5 A resolution. This structure has an external scaffold made from 240 copies of protein D, 60 copies of the internally located B protein, and contains 60 copies of each of the viral structural proteins F and G, which comprise the shell and the 5-fold spikes, respectively. The F capsid protein has a similar conformation to that seen in the mature virion, and differs from the previously determined 25 A resolution electron microscopic reconstruction of the "open" procapsid, in which the F protein has a different conformation. The D scaffolding protein has a predominantly alpha-helical fold and displays remarkable conformational variability. We report here an improved and refined structure of the closed procapsid and describe in some detail the differences between the four independent D scaffolding proteins per icosahedral asymmetric unit, as well as their interaction with the F capsid protein. We re-analyze and correct the comparison of the closed procapsid with the previously determined cryo-electron microscopic image reconstruction of the open procapsid and discuss the major structural rearrangements that must occur during assembly. A model is proposed in which the D proteins direct the assembly process by sequential binding and conformational switching.


Asunto(s)
Bacteriófago phi X 174/metabolismo , Cápside/metabolismo , Secuencia de Aminoácidos , Cápside/química , Cristalografía por Rayos X , Microscopía Electrónica , Modelos Moleculares , Datos de Secuencia Molecular , Conformación Proteica , Ensamble de Virus
9.
Br J Radiol ; 78(927): 207-18, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15730985

RESUMEN

The mean glandular doses (MGD) to samples of women attending for mammographic screening are measured routinely at screening centres in the UK Breast Screening Programme (NHSBSP). This paper reviews a large representative sample of dose measurements collected during screening in the NHSBSP in 2001 and 2002 for 53 218 films, using 290 X-ray sets, for 16 505 women. The average MGD was 2.23 mGy per oblique film and 1.96 mGy per craniocaudal film; similar to those found previously in the NHSBSP for the years 1997 and 1998. Increasing use of sophisticated units with automatic beam quality selection has reduced the radiation dose received by large breasts, with only 2% of oblique mammograms having doses in excess of 5 mGy. The increasing use of large format film has also reduced the doses to this sub-group. However the total dose per woman has increased due to the introduction of two view screening at every visit. The MGD to the standard breast was found to vary from 0.76 mGy to 2.29 mGy, with 97% of units below the recommended upper limit of 2 mGy, illustrating the benefit of strict quality control. A reduction in dose of 3% was observed between the age bands 50-54 years and 60-64 years. This study has confirmed that the proposed national diagnostic reference level (NDRL) of 3.5 mGy for 55 mm thick breasts is an appropriate value to identify systems giving unusually high doses, with just 3.5% of systems exceeding this level. In most cases these higher doses were explained by the design of one particular make of X-ray set and its mode of operation. Average doses for oblique views of average sized breasts were fairly well correlated with the dose to the standard breast, and typically 42% higher. This highlights the need for a revised definition of the standard breast used in the UK to better reflect the exposure factors and doses received in clinical practice.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Factores de Edad , Anciano , Neoplasias de la Mama/patología , Femenino , Humanos , Mamografía/métodos , Mamografía/estadística & datos numéricos , Tamizaje Masivo/métodos , Tamizaje Masivo/estadística & datos numéricos , Persona de Mediana Edad , Dosis de Radiación , Valores de Referencia , Reino Unido
10.
Diabetes Care ; 14(11): 1057-65, 1991 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1797487

RESUMEN

OBJECTIVE: The subcutaneous absorption and resulting changes in plasma insulin or analogue, glucose, C-peptide, and blood intermediary metabolite concentrations after subcutaneous bolus injection of three soluble human insulin analogues (AspB9GluB27, monomeric; AspB28, mixture of monomers and dimers; and AspB10, dimeric) and soluble human insulin were evaluated. RESEARCH DESIGN AND METHODS: Fasting healthy male volunteers (n = 7) were studied on five occasions 1 wk apart randomly receiving 0.6 nmol.kg-1 s.c. 125I-labeled AspB10 or soluble human insulin (Novolin R, Novo, Copenhagen); 1st study and 0.6 nmol.kg-1 s.c. 125I-labeled AspB28, AspB9GluB27 or soluble human insulin (2nd study). Residual radioactivity at the injection site was measured over 8 h with frequent venous sampling for plasma immunoreactive insulin or analogue, glucose, C-peptide, and blood intermediary metabolite concentrations. RESULTS: The three analogues were absorbed 2-3 times faster than human insulin. The mean +/- SE time to 50% residual radioactivity was 94 +/- 6 min for AspB10 compared with 184 +/- 10 min for human insulin (P less than 0.001), 83 +/- 8 min for AspB28 (P less than 0.005), and 63 +/- 9 min for AspB9GluB27 (P less than 0.001) compared with 182 +/- 21 min for human insulin. delta Peak plasma insulin analogue levels were significantly higher after each analogue than after human insulin (P less than 0.005). With all three analogues, the mean hypoglycemic nadir occurred earlier at 61-65 min postinjection compared with 201-210 min for the reference human insulins (P less than 0.005). The magnitude of the hypoglycemic nadir was greater after AspB9GluB27 (P less than 0.05) and AspB28 (P less than 0.001) compared with human insulin. There was a significantly faster onset and offset of responses in C-peptide and intermediary metabolite levels after the analogues than after human insulin (P less than 0.05). CONCLUSIONS: The rapid absorption and biological actions of these analogues offer potential therapeutic advantages over the current short-acting neutral soluble insulins.


Asunto(s)
Glucemia/metabolismo , Insulina/análogos & derivados , Insulina/farmacocinética , Ácido 3-Hidroxibutírico , Adulto , Alanina/sangre , Péptido C/sangre , Glicerol/sangre , Humanos , Hidroxibutiratos/sangre , Inyecciones Subcutáneas , Insulina/administración & dosificación , Insulina/farmacología , Lactatos/sangre , Masculino , Tasa de Depuración Metabólica , Receptor de Insulina/metabolismo , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/farmacocinética , Proteínas Recombinantes/farmacología , Valores de Referencia , Factores de Tiempo
11.
Diabetes Care ; 14(11): 942-8, 1991 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1797506

RESUMEN

OBJECTIVE: To study the influence of molecular aggregation on rates of subcutaneous insulin absorption and to attempt to elucidate the mechanism of absorption of conventional soluble human insulin in humans. RESEARCH DESIGN AND METHODS: Seven healthy male volunteers aged 22-43 yr and not receiving any drugs comprised the study. This study consisted of a single-blind randomized comparison of equimolar dosages of 125I-labeled forms of soluble hexameric 2 Zn2+ human insulin and human insulin analogues with differing association states at pharmaceutical concentrations (AspB10, dimeric; AspB28, mixture of monomers and dimers; AspB9, GluB27, monomeric). After an overnight fast and a basal period of 1 h, 0.6 nmol/kg of either 125I-labeled human soluble insulin (Actrapid HM U-100) or 125I-labeled analogue was injected subcutaneously on 4 separate days 1 wk apart. Absorption was assessed by measurement of residual radioactivity at the injection site by external gamma-counting. RESULTS: The mean +/- SE initial fractional disappearance rates for the four preparations were 20.7 +/- 1.9 (hexameric soluble human insulin), 44.4 +/- 2.5 (dimeric analogue AspB10), 50.6 +/- 3.9 (analogue AspB28), and 67.4 +/- 7.4%/h (monomeric analogue AspB9, GluB27). Absorption of the dimeric analogue was significantly faster than that of hexameric human insulin (P less than 0.001); absorption of monomeric insulin analogue AspB9, GluB27 was significantly faster than that of dimeric analogue AspB10 (P less than 0.01). There was an inverse linear correlation between association state and the initial fractional disappearance rates (r = -0.98, P less than 0.02). Analysis of the disappearance data on a log linear scale showed that only the monomeric analogue had a monoexponential course throughout. Two phases in the rates of absorption were identified for the dimer and three for hexameric human insulin. The fractional disappearance rates (%/h) calculated by log linear regression analysis were monomer 73.3 +/- 6.8; dimer 44.4 +/- 2.5 from 0 to 2 h and 68.9 +/- 3.5 from 2.5 h onward; and hexameric insulin 20.7 +/- 1.9 from 0 to 2 h, 45.6 +/- 5.0 from 2.5 to 5 h, and 70.6 +/- 6.3 from 5 h onward. CONCLUSIONS: Association state is a major determinant of rates of absorption of insulin and insulin analogues. The lag phase and the subsequent increasing rate of subcutaneous soluble insulin absorption can be explained by the associated state of native insulin in pharmaceutical formulation and its progressive dissociation into smaller units during the absorption process.


Asunto(s)
Insulina/análogos & derivados , Insulina/farmacocinética , Absorción , Adulto , Secuencia de Aminoácidos , Humanos , Inyecciones Subcutáneas , Insulina/administración & dosificación , Insulina/química , Radioisótopos de Yodo , Masculino , Unión Proteica , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/química , Proteínas Recombinantes/farmacocinética , Factores de Tiempo , Zinc
12.
Diabetes Care ; 15(11): 1484-93, 1992 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1334825

RESUMEN

OBJECTIVE: To evaluate the interrelationships between the rate of absorption of soluble insulin, SCBF, and anthropometry in normal subjects. RESEARCH DESIGN AND METHODS: In 12 normal men (age range 23-30 yr, BMI 18.2-41.3 kg/m2), simultaneous assessment of the absorption of 125I-labeled soluble insulin and SCBF (99mTc clearance) was performed, on separate study days, for the anterior abdominal wall, anterior midthigh, and the upper arm sites. Each site was examined in a randomized order on two separate occasions. Absorption of 125I-soluble insulin was determined by external monitoring of residual radioactivity levels at the injection site for 6 h postinjection. Residual radioactivity level-time curves, including the characteristic early phase of slow absorption of soluble insulin (the lag phase), were described using two- and three-parameter biexponential models. Anthropometric measurements included BMI, ultrasonic measurement of the subcutaneous adipose tissue layer, and caliper skin fold thickness at the anterior abdominal wall, biceps, triceps, anterior midthigh, and subscapular sites. RESULTS: A highly significant positive relationship was observed between the rate of absorption of 125I-soluble insulin and SCBF (rS = 0.44-0.52; P < 0.01-0.001). The duration of the lag phase was inversely correlated with SCBF (rS = 0.34 - 0.51; P < 0.01-0.001). Inverse relationships also were observed for the subjects' degree of adiposity with the rate of soluble insulin absorption (rS = -0.43(-)-0.71; P < 0.001) and SCBF (rS = -0.27(-)-0.62; P < 0.05-0.001). Significantly shorter lag phase was observed for the abdominal site compared with thigh and arm injection sites (P < 0.05-0.01). CONCLUSIONS: The rate of absorption of soluble insulin, including during the lag phase, is positively correlated with SCBF. Increasing adiposity prolongs the duration of the early lag phase and reduces the rate of absorption of soluble insulin and SCBF.


Asunto(s)
Tejido Adiposo/anatomía & histología , Índice de Masa Corporal , Insulina/farmacocinética , Piel/irrigación sanguínea , Absorción , Tejido Adiposo/diagnóstico por imagen , Adulto , Antropometría , Humanos , Inyecciones Subcutáneas , Insulina/administración & dosificación , Insulina Regular Porcina , Radioisótopos de Yodo , Masculino , Obesidad/fisiopatología , Flujo Sanguíneo Regional , Grosor de los Pliegues Cutáneos , Pertecnetato de Sodio Tc 99m , Ultrasonografía
13.
Diabetes Care ; 21(11): 1893-6, 1998 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9802739

RESUMEN

OBJECTIVE: To determine age- and sex-adjusted reference ranges (ASARRs) for glomerular filtration status using data from nondiabetic subjects and to apply these to newly presenting type 2 diabetic subjects. RESEARCH DESIGN AND METHODS: Glomerular filtration rate corrected for body surface area (cGFR) was determined using a radionuclide (51Cr-EDTA) method in 75 non-diabetic subjects (37 men, 38 women) and 219 type 2 diabetic subjects (157 men, 62 women). The 95% constant reference ranges (CRRs) were calculated as mean nondiabetic cGFR+/-1.96 SD. The 95% ASARRs were calculated by Altman's method from the nondiabetic cGFR versus age regression residuals for both male and female subjects. RESULTS: Using Altman's method, the intercepts, but not the gradients, of the cGFR versus age regressions were significantly different between male and female subjects (intercept difference [95% CI] 8.2 [1.3-15.1], gradient difference -0.4 [-1.1 to 0.3]). Fitting a common gradient, 95% ASARRs for normofiltration were found to be from 123.9 - (0.89 X age) to 181.7 - (0.89 x age) for male subjects, and from 116.0 - (0.89 X age) to 173.2 - (0.89 X age) for female subjects. The 95% CRR for normofiltration was 70.2-138.1 ml x min(-1) x (1.73 m)(-2). When applied to the diabetic cGFRs, the CRRs and ASARRs gave, respectively, 17% (37/219) versus 21% (46/219) hyperfiltrators and 83% (181/219) versus 79% (172/219) normofiltrators. Using the ASARRs, 14 normofiltrators (6 men, 8 women) were reclassified as hyperfiltrators (change [n/total n] [95% CI] 8% [14/181] [4-12]), and 5 hyperfiltrators (5 men, 0 women) were reclassified as normofiltrators (change 14% [5/37] [5-30]). CONCLUSIONS: We conclude that age and sex adjustment are essential to assess glomerular filtration status.


Asunto(s)
Diabetes Mellitus Tipo 2/fisiopatología , Glomérulos Renales/fisiopatología , Adulto , Factores de Edad , Anciano , Femenino , Tasa de Filtración Glomerular , Humanos , Masculino , Persona de Mediana Edad , Valores de Referencia , Factores Sexuales
14.
Arch Surg ; 128(3): 346-8, 1993 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8442694

RESUMEN

Hypokalemia is an uncommon presentation of renovascular hypertension. Although renal artery stenosis has been associated with hypokalemia secondary to hyperreninemic hyperaldosteronism, few reports have actually evaluated the pathophysiologic changes in such a patient with renovascular hypertension. We studied a patient before and after surgical revascularization who presented with severe hypertension and marked, symptomatic hypokalemia. Before surgery, the patient had excessive urinary potassium secretion, markedly increased secretion of renin after captopril stimulation, and mild secondary hyperaldosteronism. Postoperatively, the patient's blood pressure decreased moderately and the serum and urinary potassium values normalized. After revascularization, plasma renin activity both before and after captopril stimulation and serum aldosterone levels decreased markedly. These findings demonstrate that renovascular hypertension may rarely present with symptomatic hypokalemia secondary to excessive aldosterone secretion. Improvement in the renal ischemic state is accompanied by rapid correction of the metabolic disturbances associated with hyperreninemic hyperaldosteronism.


Asunto(s)
Hipopotasemia/diagnóstico , Obstrucción de la Arteria Renal/diagnóstico , Aldosterona/sangre , Diagnóstico Diferencial , Humanos , Hiperaldosteronismo/sangre , Hiperaldosteronismo/fisiopatología , Hipertensión Renovascular/diagnóstico , Hipertensión Renovascular/fisiopatología , Hipertensión Renovascular/cirugía , Hipopotasemia/fisiopatología , Masculino , Persona de Mediana Edad , Potasio/sangre , Potasio/orina , Arteria Renal/cirugía , Obstrucción de la Arteria Renal/fisiopatología , Obstrucción de la Arteria Renal/cirugía , Renina/sangre , Arteria Esplénica/cirugía
15.
Br J Radiol ; 69(818): 182-5, 1996 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-8785649

RESUMEN

Intensifying screens for mammography may be categorized as fine, giving priority to image quality, or medium, achieving a lower dose at the expense of some image quality. It is important to be aware of the possible consequences of changing from a fine to a medium screen. The relative image quality and dose of four film-screen combinations (Fuji MIMA/UMMA film with Fuji HR Mammo Fine and HR Mammo Medium screens, Kodak MinRE film with Kodak MinR and MinR Medium screens) were evaluated using Leeds TOR(MAM) and Ackermann test objects. In each case, the performance of the medium screen was compared with that of the fine screen from the same manufacturer; it was not the purpose of this study to compare one manufacturer's products with the other's. Both medium screens showed measurably poorer image quality than the corresponding fine screens. The reduction in dose was only 30-40%. Careful evaluation of other dose reduction methods is recommended before changing from fine to medium screens.


Asunto(s)
Mamografía/instrumentación , Película para Rayos X , Pantallas Intensificadoras de Rayos X , Humanos , Fantasmas de Imagen , Dosis de Radiación
16.
Br J Radiol ; 68(808): 394-9, 1995 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7795976

RESUMEN

Measurements of compressed breast thickness during mammography is necessary for the calculation of breast dose. In theory, it should be possible to calculate breast thickness from the separation of images of radio-opaque markers attached to the compression paddle. Such a technique has been evaluated on two models of X-ray set using simulated and real breasts. The results show that breast thickness at a given position can be determined with an average error of about 2 mm by this method, which is likely to be adequate for dosimetry.


Asunto(s)
Mama/anatomía & histología , Mamografía , Dosis de Radiación , Femenino , Humanos , Radiología/métodos
17.
Br J Radiol ; 73(867): 278-87, 2000 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10817044

RESUMEN

The mean glandular doses (MGDs) to samples of women attending for mammographic screening are measured routinely at screening centres in the UK Breast Screening Programme (NHSBSP). This paper reviews the data collected during screening in the NHSBSP in 1997 and 1998 for 23,752 films, using 171 X-ray sets, for 8745 women. Average MGD was 2.03 mGy per oblique film and 1.65 mGy per craniocaudal film, similar to the MGDs found previously in the NHSBSP for the years 1994 and 1995. MGD was found to increase with compressed breast thickness where the tube potential was selected manually, so that the average dose for 10 cm thick breasts was 2.7 times the average for all breasts. For large breasts (> 70 mm) the use of X-ray sets such as the IGE DMR, which automatically select the beam quality for each breast, resulted in lower doses compared with sets using manual tube potential selection. MGD to the standard breast was found to vary from 0.7 to 2.2 mGy and to be correlated with the average MGD per mediolateral oblique film for the women screened on that system (R = 0.79). No correlation between age and MGD was found within the invited age range of 50-64 years.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Tamizaje Masivo/normas , Factores de Edad , Mama/anatomía & histología , Femenino , Humanos , Mamografía , Persona de Mediana Edad , Control de Calidad , Dosis de Radiación
18.
Br J Radiol ; 71(845): 517-27, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-9691897

RESUMEN

A survey of radiation dose and compressed breast thickness was conducted in samples of women undergoing mammography in the United Kingdom National Health Service breast screening programme. The aims were to determine the average value and distribution of dose and thickness, and to identify technical difficulties in carrying out such a survey. Values of breast thickness and mean glandular dose, calculated from exposure factors and measured X-ray beam parameters, were collected for 4633 women in 92 screening units in 1994 and 1995. The median (lower quartile, upper quartile) dose per film was 1.7 (1.2, 2.4) mGy for the mediolateral oblique view (mean thickness 57 mm) and 1.4 (1.1, 2.0) mGy for the craniocaudal view (mean thickness 52 mm). The median dose per woman was 1.8 (1.3, 2.5) mGy for a one-view examination and 3.3 (2.3, 4.6) mGy for a two-view examination. The dose per film showed an exponential relationship to breast thickness, but no relationship was found between median dose and median breast thickness in the different screening units, possibly because of errors in breast thickness measurement. The values of breast thickness and dose were generally consistent with those in other published surveys, allowing for differences in radiographic technique. No relationship between breast dose and standard optical density was demonstrated. Some recommendations for the conduct of future surveys of breast dose in the UK are proposed.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Mama/efectos de la radiación , Mamografía , Tamizaje Masivo , Dosis de Radiación , Mama/anatomía & histología , Neoplasias de la Mama/prevención & control , Femenino , Encuestas de Atención de la Salud/métodos , Humanos , Mamografía/efectos adversos , Mamografía/normas , Persona de Mediana Edad , Proyectos Piloto , Reino Unido
19.
Arch Gerontol Geriatr ; 9(2): 115-22, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2589913

RESUMEN

Four elderly patients (aged 68-87 yr) with osteoarthritis were treated with 20 mg of tenoxicam (a new non-steroidal anti-inflammatory drug) daily for at least 12 weeks. Tenoxicam did not appear to have any harmful effect on glomerular filtration rate and effective renal plasma flow, as measured by a single intravenous injection of 51Cr-EDTA and 125I-iodohippurate. Plasma concentration of tenoxicam indicated good compliance, and no evidence of unexpected accumulation of tenoxicam in the plasma was observed during 12 weeks of medication.


Asunto(s)
Antiinflamatorios no Esteroideos/efectos adversos , Radioisótopos de Cromo , Radioisótopos de Yodo , Riñón/efectos de los fármacos , Piroxicam/análogos & derivados , Anciano , Anciano de 80 o más Años , Antiinflamatorios no Esteroideos/sangre , Antiinflamatorios no Esteroideos/uso terapéutico , Femenino , Tasa de Filtración Glomerular , Humanos , Riñón/fisiología , Masculino , Piroxicam/efectos adversos , Piroxicam/sangre , Piroxicam/uso terapéutico
20.
J Speech Lang Hear Res ; 40(3): 627-41, 1997 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9210119

RESUMEN

This study examined visual analog scaling (VAS) judgments of disfluency by normal listeners in response to oral reading by speakers with spasmodic dysphonia (SD) and by nondysphonic controls, as well as the variables of frequency of occurrence of disfluencies, speaking rate, number of reading errors, and temporal acoustic measures of interword interval duration and articulation time. MANOVA yielded statistically significant differences between SD and control speakers for all variables except reading errors. Although no significant fluency-related differences were observed in terms of type of vocal spasm or voice tremor, significant differences in disfluency measures were obtained for clinical ratings of severity of dysphonia. Greater dysphonia severity ratings were associated with decreased fluency, but milder ratings were not necessarily associated with disfluency. Stepwise multiple regression analysis demonstrated that frequency of disfluency occurrence, speaking rate, and reading errors accounted for more than three fourths of the variability in VAS judgments of disfluency. Findings suggest that although disfluency is not a defining feature of SD, it does contribute significantly to the overall clinical impression of severity of the disorder.


Asunto(s)
Trastornos de la Voz/diagnóstico , Adulto , Anciano , Humanos , Persona de Mediana Edad , Análisis Multivariante , Acústica del Lenguaje , Medición de la Producción del Habla
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA