Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
1.
Clin Nutr ESPEN ; 33: 42-46, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31451274

RESUMEN

INTRODUCTION: Most studies on alternative intravenous lipid emulsion (IVLE) versus conventional IVLE have been conducted in the critically ill patients. The benefits of alternative IVLE in non-critically ill patients is uncertain. We aim to determine clinical outcome difference between alternative IVLE versus conventional IVLE in non-critically ill patients. METHOD: All patients on parenteral nutrition (PN) from July 2007 to September 2010 were identified. Patients were stratified into two groups: conventional IVLE (soybean oil-based) and alternative IVLEs, namely MCT oil-based, olive oil-based and fish oil-containing IVLE. RESULT: Three hundred and eighty-eight patients were included in the study. Ninety-one patients received soybean-based IVLE, 59 patients received MCT oil-based IVLE, 141 patients received olive oil-based IVLE and 97 patients received fish oil-containing IVLE. Adjusting the effect of baseline covariates in separate multiple linear/logistic regression models, there were no differences in mortality, readmission, length of stay and infection between conventional IVLE group and alternative IVLEs group, the adjusted p-value was 0.64, 0.06, 0.36 and 0.18 respectively. However, there was a significant change in day 5 CRP between these two groups (8.43 g/L (SD 112.2) vs -41.2 (SD 106.4); adjusted p-value = 0.01). There was no difference in day 5 albumin between these two group (-1.03 (SD 5.1) vs -0.1 (SD 5.3); adjusted p-value = 0.08). CONCLUSION: Our study showed that pertinent clinical outcomes in non-critically ill patients who received either conventional IVLE or alternative IVLEs were the same. However, there was significant reduction in day-5 CRP in alternative IVLE compared to conventional IVLE.


Asunto(s)
Enfermedad Crítica/terapia , Emulsiones Grasas Intravenosas/administración & dosificación , Anciano , Femenino , Aceites de Pescado , Hospitalización , Humanos , Modelos Lineales , Modelos Logísticos , Masculino , Persona de Mediana Edad , Mortalidad , Aceite de Oliva , Nutrición Parenteral , Aceite de Soja , Resultado del Tratamiento
2.
Atherosclerosis ; 113(2): 273-87, 1995 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7605366

RESUMEN

We have studied low density lipoprotein (LDL) subclass distribution in a group of male patients with non-insulin-dependent diabetes mellitus (NIDDM) and investigated its relationships to fasting and postprandial triglyceride (TG)-rich lipoproteins, insulin resistance, lipoprotein lipase (EC 3.1.1.3; LPL), hepatic lipase (EC 3.1.1.34; HL), lecithin:cholesterol acyl transferase (EC 2.3.1.43; LCAT) and cholesteryl ester transfer protein (CETP) activities. LDL was subfractionated by density gradient ultracentrifugation. Postprandial lipoproteins were measured after an oral fat load using retinyl palmitate as a marker for intestinal TG-rich lipoproteins. Hypertriglyceridaemic NIDDMs (HTG) had a preponderance of small dense LDL particles present in the plasma and reduced amounts of large buoyant species when compared to normotriglyceridaemic patients (NTG) and controls. Both groups of diabetics were more insulin resistant than the controls (P < 0.05) and had raised concentrations of proinsulin (P < 0.05), although insulin content did not differ significantly. 32-33 split proinsulin (SPI) was the major insulin-like molecule present in HTG and was present in significantly higher amounts in these patients (P < 0.05) than either NTG or control subjects and correlated significantly with the presence of small dense LDL particles. After a test meal, the postprandial chylomicron response was greater in HTG than either NTG diabetics or controls (P < 0.05). Chylomicron remnants were present to a greater extent in HTG than in NTG and controls (P < 0.05), although in this case NTG also contained more chylomicron remnants than control subjects (P < 0.05). There was no difference in the LPL activity, CETP and LCAT between diabetics and controls, whereas an increase in hepatic lipase activity was seen in the HTG diabetics (P < 0.05). Both CETP and LCAT activities increased postprandially. Multivariate analysis showed that TG, HDL content and HL activity were the most important determinants of small dense LDL concentration in the fasting state (R2 = 67%). Postprandially, chylomicron remnant clearance, HL and insulin resistance were the major determinants (R2 = 61%) of LDL-III.


Asunto(s)
Diabetes Mellitus Tipo 2/sangre , Ayuno/sangre , Hipertrigliceridemia/sangre , Resistencia a la Insulina/fisiología , Insulina/sangre , Lipoproteínas LDL/sangre , Estudios de Casos y Controles , Centrifugación por Gradiente de Densidad , Diabetes Mellitus Tipo 2/complicaciones , Ingestión de Alimentos/fisiología , Humanos , Hipertrigliceridemia/complicaciones , Lipasa/sangre , Masculino , Persona de Mediana Edad , Análisis Multivariante , Fosfatidilcolinas/sangre , Proinsulina/sangre , Radioinmunoensayo
3.
Eur J Gastroenterol Hepatol ; 14(5): 521-8, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-11984150

RESUMEN

INTRODUCTION: We postulated that the oro-oral route of transmission between spouses could be an important route of transmission of Helicobacter pylori. AIMS: To estimate the prevalence of different genotypes of H. pylori as distinguished by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in our local population, and to compare the genotypes of H. pylori isolated from patients and their spouses. METHODS: Gastric biopsies were obtained from 183 dyspeptic patients during endoscopy. PCR for H. pylori was carried out using the uceC gene for amplification, and PCR products were digested further for RFLP analysis using the enzyme MboI. Spouses of H. pylori-positive index cases were screened for the infection using serological testing; if found to be positive serologically, endoscopy and gastric biopsies were performed for genotypic study of the micro-organism. For couples with indistinguishable H. pylori strain on RFLP with restriction endonuclease MboI, the process of RFLP was repeated with digestion of the PCR products using restriction endonuclease HhaI. RESULTS: We established our PCR technique to be 89.5% sensitive and 95.5% specific. Eighty-nine subjects were found to be H. pylori positive by PCR, and eight different genotypic strains were found according to our RFLP analysis. Two genotypes accounted for 80.8% of the cases. Sixteen of 31 spouses tested serologically for H. pylori were positive. All 13 spouses who agreed to undergo endoscopy were PCR positive for H. pylori. Five couples shared indistinguishable H. pylori genotypes, but this strain was also the commonest genotype in our local population, as based on RFLP with restriction endonuclease MboI. Further RFLP on the PCR products on these five couples using restriction endonucleases HhaI showed that the H. pylori isolated from these five couples were of different strains. CONCLUSION: The oro-oral route of transmission between spouses is unlikely to be an important mode for H. pylori infection.


Asunto(s)
Infecciones por Helicobacter/transmisión , Helicobacter pylori , Adulto , Ensayo de Inmunoadsorción Enzimática , Femenino , Gastroscopía , Genotipo , Helicobacter pylori/genética , Humanos , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Sensibilidad y Especificidad
4.
Eur J Gastroenterol Hepatol ; 12(10): 1129-34, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11057459

RESUMEN

OBJECTIVES: This study aimed to determine intra-patient colonization patterns of Helicobacter pylori strains based on DNA fingerprinting and antibiotic susceptibility. METHODS: Two biopsies, one from the antrum and one from the body of the stomach, were taken from 97 patients. Prior informed consent was obtained. The status of cagA gene of H. pylori strains was analysed by using the polymerase chain reaction (PCR) technique, while DNA fingerprints were generated by PCR-based, random amplified polymorphic DNA (RAPD) fingerprinting. The antibiotic susceptibility of the H. pylori isolates was examined by the disk diffusion method. RESULTS: A total of 51 pairs of H. pylori strains were isolated from both antrum and body specimens of 51 patients. This included two patients who were endoscoped twice because of treatment failure. All strains were positive for cagA gene by PCR. These 51 patients were found to harbour a single strain of H. pylori with identical or highly similar DNA profiles by PCR-based RAPD fingerprinting. In four of the 51 pairs, the DNA patterns of H. pylori from antrum and body showed minor differences, while three pairs of strains with different metronidazole sensitivities showed identical DNA fingerprints. Interestingly, the two treatment failure patients remained colonized with the strains that had the same RAPD fingerprinting patterns before and after treatment. CONCLUSION: The present study demonstrates that a single H. pylori strain colonizes a single stomach. However, this single genotypic strain may exhibit different metronidazole susceptibility in different parts of stomach.


Asunto(s)
Infecciones por Helicobacter/microbiología , Helicobacter pylori/aislamiento & purificación , Antro Pilórico/microbiología , Estómago/microbiología , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/farmacología , Biopsia , Dermatoglifia del ADN , Femenino , Helicobacter pylori/clasificación , Helicobacter pylori/efectos de los fármacos , Helicobacter pylori/genética , Humanos , Masculino , Metronidazol/farmacología , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Datos de Secuencia Molecular , Antro Pilórico/patología , Distribución Aleatoria , Técnica del ADN Polimorfo Amplificado Aleatorio , Estómago/patología
5.
Artículo en Inglés | MEDLINE | ID: mdl-3349772

RESUMEN

BASIC programs have been written to analyse minimal inhibitory concentration (MIC) antimicrobial susceptibility results for large numbers of organisms and a wide variety of antimicrobials. The output of the programs lists the numbers, percentages, cumulative numbers and cumulative percentages of organisms inhibited at different concentrations. The distribution of MICs are additionally printed as a histogram. The range, MIC for 50% and 90% of organisms (MIC50 and MIC90 respectively), and the geometric mean MIC of each drug are also calculated.


Asunto(s)
Pruebas de Sensibilidad Microbiana/métodos , Programas Informáticos , Procesamiento Automatizado de Datos , Microcomputadores , Lenguajes de Programación
6.
Singapore Med J ; 40(12): 738-41, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10709423

RESUMEN

INTRODUCTION: Eradication of Helicobacter pylori (H. pylori) cures and prevents the relapse of duodenal ulceration. Different treatment regimes for the eradication of H. pylori have been used and the most successful eradication regimens have been one week treatments with a proton pump inhibitor and two antibiotics. AIM OF STUDY: To examine the eradication rate of H. pylori with a one week regimen consisting of OCT (Omeprazole 20 mg BD, Clarithromycin 250 mg BD, Tinidazole 500 mg BD). This treatment regimen has been used for H. pylori eradication in our department since the end of 1996. METHODS: Patients diagnosed to have duodenal ulcer in 1997 were retrospectively reviewed. Infection with H. pylori must be documented either by gastric biopsy or by a positive CLO test. Eradication of H. pylori was confirmed by negative 14C urea breath test or by histology at least four weeks after cessation of therapy. RESULTS: The review was performed on 251 patients. There were 177 males, 74 females. The median age was 51 (18-77) years. H. pylori infection was confirmed by CLO test in 170 patients and by histology in 72 patients. Thirty patients did not undergo further investigation after therapy to confirm the eradication. Of the remaining 221 patients, H. pylori was successfully eradicated in 198 patients (89.6%) as confirmed by 14C urea breath test (190 patients) or repeat gastroscopy and gastric biopsy (31 patients). There were no serious adverse events documented. CONCLUSIONS: Our retrospective study showed that the one week regimen used in our department is effective for the eradication of H. pylon in nearly 90% of infected cases.


Asunto(s)
Antibacterianos/administración & dosificación , Antiulcerosos/administración & dosificación , Antitricomonas/administración & dosificación , Claritromicina/administración & dosificación , Úlcera Duodenal/microbiología , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori , Omeprazol/administración & dosificación , Tinidazol/administración & dosificación , Administración Oral , Adolescente , Adulto , Anciano , Quimioterapia Combinada , Úlcera Duodenal/tratamiento farmacológico , Femenino , Infecciones por Helicobacter/patología , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento
7.
Singapore Med J ; 42(7): 317-21, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11599627

RESUMEN

BACKGROUND: There has been a gradual increase in the proportion of Singapore patients with metronidazole resistant strains of Helicobacter pylori. We studied the efficacy of a nitroimidazole containing regime in eradicating H. pylori. METHODS: Consecutive treatment naive patients with peptic ulcer disease and culture proven H. pylori were recruited. From each patient, two antral biopsies were taken for rapid urease test and two for histology. Two biopsies each from the gastric antrum and corpus were taken for H. pylori culture. Antibiotic sensitivity to amoxycillin, metronidazole, clarithromycin and tetracycline were tested using the disc diffusion method. Patients were treated with lansoprazole 30 mg bd, tinidazole 500 mg bd and clarithromycin 500 mg bd for seven days. Successful eradication was defined as either negative urea breath tests 4 and 12 weeks after treatment, or negative histology and culture at least four weeks after the end of treatment. RESULTS: A total of 64 patients were culture positive (51 males, 13 females). Forty-two patients had duodenal ulcers (DU), 17 gastric ulcers (GU), and 5 DU and GU. Metronidazole resistance was detected in 16 patients (25%). Three of the 16 patients (19%) had a mixed population of resistant and sensitive strains of H. pylori. None of the H. pylori isolates were resistant to amoxycillin, tetracycline or clarithromycin. Overall, eradication was achieved in 51/64 patients (80%). Eradication rate was 88% (42/48) among those with metronidazole sensitive strains, and 56% (9/16) among those with metronidazole resistant strains (p < 0.02). CONCLUSION: A high proportion of our patients with metronidazole resistant strains of H. pylori failed eradication therapy when a nitroimidazole containing regime was used. It may not be appropriate to use a nitroimidazole containing without prior knowledge of the antibiotic sensitivity pattern of the H. pylori isolate.


Asunto(s)
Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori/aislamiento & purificación , Nitroimidazoles/uso terapéutico , 2-Piridinilmetilsulfinilbencimidazoles , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/uso terapéutico , Claritromicina/uso terapéutico , Quimioterapia Combinada , Femenino , Humanos , Lansoprazol , Masculino , Persona de Mediana Edad , Omeprazol/análogos & derivados , Omeprazol/uso terapéutico , Singapur , Tinidazol/uso terapéutico
8.
BMJ ; 297(6642): 173-5, 1988 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-3044508

RESUMEN

Cholestyramine and bezafibrate were compared individually and in combination in the treatment of 18 patients with heterozygous familial hypercholesterolaemia. The study used a double blind, placebo controlled block design with a placebo run in period of two months followed by three phases of active treatment, each of two months' duration. Patients were randomly allocated to one of the six possible sequences of medication so that three patients would be treated with each sequence. Two patients withdrew from the study before completion. The median concentration of total cholesterol decreased from 9.65 mmol/l (interquartile range 8.62 to 8.72) to 7.24 mmol/l (6.70 to 7.52) with cholestyramine, to 8.09 mmol/l (7.18 to 8.68) with bezafibrate, and to 6.31 mmol/l (5.84 to 7.27) with the combination. This fall was due almost entirely to a decrease in the low density lipoprotein cholesterol concentration, and the combination was significantly more effective than either drug alone. The 98% confidence intervals for the median differences between the combination and cholestyramine and the combination and bezafibrate were 0.04 to 1.49 mmol/l and 0.51 to 2.18 mmol/l respectively. These results suggest that this combination is an effective and useful treatment in heterozygous familial hypercholesterolaemia.


Asunto(s)
Bezafibrato/uso terapéutico , Resina de Colestiramina/uso terapéutico , Hiperlipoproteinemia Tipo II/tratamiento farmacológico , Adulto , Ensayos Clínicos como Asunto , Método Doble Ciego , Quimioterapia Combinada , Femenino , Heterocigoto , Humanos , Masculino , Persona de Mediana Edad , Distribución Aleatoria
12.
Gut ; 28(6): 707-13, 1987 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-3623217

RESUMEN

The surface pH of rat distal colonic mucosa and human rectal mucosa was measured in vitro using first a small pH electrode with a flattened tip. In buffer with pH 7.56 the mean rat colonic surface pH was 6.72. Lowering the buffer pH in steps resulted in a small fall in surface pH, the values being buffer pH 7.06 surface pH 6.64, buffer pH 6.58 surface pH 6.61 and finally buffer pH 6.09 surface pH 6.39. Similar results were obtained with a buffer where butyrate, 30 mmol/l replaced chloride and when a CO2/bicarbonate buffer was used. During the time taken for the study transmural potential difference only changed by 1-2 mV. Serosal surface pH changed with buffer pH, suggesting that the maintained surface pH is a property of the mucosal surface only. The surface pH of human rectal mucosa was similar to that of rat distal colonic mucosa. As buffer pH fell from pH 7.51 to 5.96 mucosal surface pH only fell from pH 6.80 to 6.26. The values obtained in ulcerative proctitis did not differ from normal mucosa. Secondly pH microelectrodes were used to measure the juxta mucosal pH and the pH-microclimate thickness when luminal pH was controlled. The microclimate had a pH 6.63 adjacent to the mucosa with a thickness of 840 micron. The importance of mucus in maintaining the microclimate was shown by n-acetyl cysteine thinning and prostaglandin E2 thickening the layer. These results describe a surface microclimate in the large intestine of appreciable thickness and a constant juxta mucosal pH. Luminal pH changes produce only a small change in microclimate pH.


Asunto(s)
Mucosa Intestinal/fisiología , Intestino Grueso/fisiología , Proctitis/fisiopatología , Adulto , Anciano , Animales , Colon/fisiología , Electrodos , Femenino , Humanos , Concentración de Iones de Hidrógeno , Intestino Grueso/fisiopatología , Masculino , Microelectrodos , Persona de Mediana Edad , Ratas , Ratas Endogámicas , Recto/fisiología
13.
Hum Reprod ; 11(12): 2635-9, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9021365

RESUMEN

Declining sperm count reports have caused enormous concern to both the scientific community and to society. We reproduced the linear regression analysis and the quadratic model analysis using the 50 year sperm count data published in Carlsen's report and found that neither model adequately described the data. The reported decline in sperm count could be due to observational bias and overinterpretation of linear regression. In fact only 36% of the total variability in sperm count was explained by the linear model and 42% by the quadratic model. The linear model was no longer valid when three new European reports on sperm counts were included in the analysis. The quadratic model, however, suggested an upward trend of sperm count after 1975 (R2 = 0.48, P < 0.0001). Factors other than the 'passage of time' may have contributed to the initial decline of sperm count. An immediate candidate was demography. Our analysis showed that sperm counts in USA were significantly higher in 1938-1956 compared with those in 1957-1974 and 1975-1988, but not in the European or Asian/African/South American countries. The variability of the USA sperm count (1938-1988) explained by the linear and quadratic models was found to be 71 and 70% respectively. The quadratic model importantly indicated that the sperm count in USA decreases asymptotically towards a limiting value and global sperm counts could be increasing since 1970. The non-uniform nature of the global sperm count change suggested that local variations in pollution, diet but not global warming were important determinants of reproductive health.


Asunto(s)
Demografía , Modelos Estadísticos , Recuento de Espermatozoides , Humanos , MEDLARS , MEDLINE , Masculino , Análisis de Regresión , Factores de Tiempo
14.
J Clin Microbiol ; 26(1): 161-3, 1988 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-3343311

RESUMEN

A computer program has been developed on an IBM-PC-compatible microcomputer to analyze antimicrobial susceptibility results of large numbers of organisms tested against a variety of antimicrobial agents. For each species, the output includes the numbers, percentages, cumulative numbers, and cumulative percentages of organisms inhibited at different concentrations of each drug, the MICs for 50 and 90% of organisms tested, MIC ranges, and geometric mean MICs. The distributions of MICs are also plotted as histograms. The program was written in dBASE III command language, but a compiled version allows rapid program execution independently of the dBASE III package.


Asunto(s)
Pruebas de Sensibilidad Microbiana , Programas Informáticos , Microcomputadores
15.
Diabet Med ; 18(2): 109-15, 2001 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11251673

RESUMEN

AIMS: The reasons for the increased incidence of diabetic nephropathy in African-Caribbean compared with Caucasian subjects are poorly understood. Increased oxidative stress is linked to the development of endothelial dysfunction and histological abnormalities associated with diabetic renal disease. Therefore, it was assessed whether a marker of oxidative stress, lipid hydroperoxide (LOOH) and endothelial damage, von Willebrand factor (vWF) varied according to ethnic origin in the presence or absence of early diabetic nephropathy. METHODS: Eighty-eight patients with Type 2 diabetes mellitus of African-Caribbean or Caucasian origin without a history of cardiovascular disease or clinical proteinuria were studied. Patients were classified as having microalbuminuria or normal albumin excretion. Fasting plasma vWF and LOOH were measured by an inhouse enzyme-linked immunoassay and ferrous oxidation with xylenol orange (FOX) assay, respectively. The relationship of LOOH to urinary albumin status, the metabolic disturbances of diabetes, blood pressure and ethnic origin were assessed using multivariate analysis. RESULTS: Compared with Caucasian patients those of African-Caribbean origin had higher systolic blood pressure and HDL-cholesterol (157.8 +/- 17.0 vs. 147.8 +/- 24.4, P = 0.041 and 1.6 +/- 0.4 vs. 1.3 +/- 0.5, P = 0.018) but lower total triglycerides (1.3 +/- 0.8 vs. 1.9 +/- 1.1, P = 0.008). LOOH was significantly higher in the African-Caribbean patients compared with Caucasians (5.98 +/- 2.49 vs. 4.49 +/- 2.19, P = 0.006). vWF tended to be higher in microalbuminuric patients but showed no variation with ethnicity. In logistic regression analysis, LOOH was the only independent predictor of a raised albumin excretion rate (P = 0.008). In multiple regression analysis, African-Caribbean ethnicity (P = 0.020) HDL-cholesterol (P = 0.036), total triglycerides (P = 0.002) and a raised albumin excretion rate (P = 0.002) were independent predictors of LOOH. CONCLUSIONS: In this group of Type 2 diabetic patients an increase in LOOH is associated with abnormal urinary albumin excretion. African-Caribbean origin was a determinant of LOOH independently of microalbuminuria. It is postulated that increased oxidative stress is of pathophysiological significance in accelerating the development of renal disease in African-Caribbean patients.


Asunto(s)
Diabetes Mellitus Tipo 2/fisiopatología , Nefropatías Diabéticas/epidemiología , Peróxidos Lipídicos/sangre , Negro o Afroamericano , Albuminuria/epidemiología , Biomarcadores/sangre , Población Negra , Presión Sanguínea , Índice de Masa Corporal , Región del Caribe/etnología , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/orina , Susceptibilidad a Enfermedades , Femenino , Humanos , Londres , Masculino , Persona de Mediana Edad , Análisis Multivariante , Estrés Oxidativo , Análisis de Regresión , Factores de Riesgo , Población Blanca , Factor de von Willebrand/análisis
16.
Biochem J ; 313 ( Pt 3): 781-6, 1996 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-8611155

RESUMEN

High-density lipoprotein (HDL) has been proposed as the principal carrier of hydroperoxides in plasma, based upon data gathered with an HPLC-chemiluminescence technique. To test this hypothesis we have measured total lipid hydroperoxides in native plasma using the ferrous oxidation in Xylenol Orange (FOX) assay and then fractionated plasma into very-low-density lipoprotein (LDL) and HDL fractions. Hydroperoxides were found to accumulate principally (more than 65%) in LDL, as judged by hydroperoxide content per amount of protein or cholesterol, or expressed as a proportion of total hydroperoxide in plasma. Plasma was also incubated at 37 degrees C in the presence and absence of 2,2'-azo-bis-(2-amidinopropane) hydrochloride (AAPH), an azo-initiator of lipid peroxidation. The majority of hydroperoxides generated in plasma were recovered in the LDL fraction. Furthermore, when isolated lipoproteins were subject to oxidation initiated by AAPH, very-low-density lipoprotein and LDL showed the greatest propensity for hydroperoxide accumulation, whereas HDL seemed relatively resistant. Estimates for plasma and LDL peroxidation based upon techniques which measure total lipid hydroperoxides suggest that levels of hydroperoxides in plasma and LDL are far higher than that those estimates generated by ostensibly more selective techniques. Higher levels of hydroperoxides in LDL than those reported by HPLC-chemiluminescence also seem in greater accordance with other available data concerning LDL oxidation.


Asunto(s)
Proteínas Portadoras/sangre , Peróxidos Lipídicos/sangre , Lipoproteínas LDL/sangre , Amidinas , Cromatografía Líquida de Alta Presión , Colorantes Fluorescentes , Humanos , Técnicas In Vitro , Peroxidación de Lípido , Lipoproteínas HDL/sangre , Mediciones Luminiscentes , Fenoles , Sulfóxidos , Xilenos
17.
Tissue Antigens ; 62(6): 527-35, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14617036

RESUMEN

Linkage and association studies implicate the human leucocyte antigen (HLA) region in genetic susceptibility to ulcerative colitis (UC). However, associations with specific variants have been inconsistent, even within defined ethnic groups. A genetic basis for the disease heterogeneity of UC may account for these discrepant findings from studies in unselected populations. Here, we examine the contribution of the HLA region to the clinical phenotype of UC. We studied 321 accurately phenotyped patients recruited from a single UK centre, with a median follow-up time of 15 years. Individuals were genotyped for 340 polymorphisms constructed into 25 gene-specific allelic haplotypes between HLA-A and Tapasin. Data were analysed with respect to age of onset, disease extent and severity. Strongest association with overall susceptibility was identified with HLA-DRB1 alleles replicating previous studies (DRB1*0103, DRB1*1502 and DRB1*0401). We report a novel association with homozygosity of a tumour necrosis factor (TNF) promoter haplotype (TNF-1031T, -863C, -857C, -380G, -308G and -238G) and distal disease extent that does not extend with time (distal vs total 40.9 vs 25.7%; RR = 2.0; 95% CI 1.23-3.24). We confirm the association of DRB1*0103 with total disease and/or disease requiring colectomy and further demonstrate that DRB1*0103 is associated with shorter time to surgery. Genes in the HLA play a role in modifying disease phenotype. Further studies are required to dissect how these genes functionally interact with each other and with environmental factors to determine clinical patterns of disease


Asunto(s)
Colitis Ulcerosa/genética , Antígenos HLA/genética , Complejo Mayor de Histocompatibilidad , Adolescente , Adulto , Edad de Inicio , Anciano , Niño , Estudios de Cohortes , Femenino , Predisposición Genética a la Enfermedad , Haplotipos , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Fenotipo , Polimorfismo de Nucleótido Simple
18.
Hum Fertil (Camb) ; 3(3): 207-213, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11844380

RESUMEN

The effects of age, parity and male infertility status on pregnancy outcome were studied in a cohort of 720 women receiving donor insemination (DI) treatment. Twenty-two percent of women failed to complete the treatment, leaving 562 women receiving 3202 cycles of DI for assessment. Of the 321 of pregnancies achieved, 57 (17.8%) ended in a miscarriage. After further DI treatments, 64.7% of mothers who had miscarried succeeded in giving birth. There was some evidence to indicate a trend of decreasing pregnancy rate with increasing maternal age, although this result was not significant (log rank trend statistics = 3.44, P > 0.05). The pregnancy rates of multiparous and primiparous women were significantly different, irrespective of their partner's infertility status (azoospermia: log rank statistics = 3.74, P less-than-or-eq, slant 0.05; oligozoospermia: log rank statistics = 4.71, P < 0.03). Furthermore, multiparous women were more likely to become pregnant than primiparous women (azoospermia: hazard ratio = 1.29; oligozoospermia: hazard ratio = 1.50). There was no significant association between miscarriage rate and maternal age (log rank trend statistics = 0.99, P > 0.05). The small number of older women (> 35 years) may confound this result. The mean (plus minus SD) sperm donor age was 23.6 years (plus minus 3.5 years). The implications of these observations are discussed.

19.
Hum Reprod ; 17(12): 3157-61, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12456617

RESUMEN

BACKGROUND: Adult cancer patients are routinely offered pre-treatment sperm cryopreservation. However, only recently has the welfare of adolescent cancer sufferers gained momentum, including their infertility, and unsurprisingly relatively little is known about their semen quality and feasibility of cryopreservation. METHODS AND RESULTS: A total of 238 adolescent cancer patients referred to our centre between 1991 and 2000, from post-pubertal age up to 19 years 11.9 months, were included. Their semen was processed after appropriate counselling. Semen cryopreservation was possible in 205 of the initial 238 patients referred (86.1%). The pathology of the cancer cases included Hodgkin's lymphoma, non-Hodgkin's lymphoma, osteosarcoma, Ewing's sarcoma, acute lymphoblastic leukaemia (ALL), acute myeloid leukaemia (AML), testicular, leukaemia, and others. The mean sperm counts were broadly uniform across the disease and age groups, except for the AML group. There was no cancer group analysed in which sperm could not be stored. Semen volume was broadly uniform across the disease groups, except the ALL and Ewing's sarcoma groups, which showed relatively lower and higher mean semen volumes respectively. Older adolescent patients appeared to have a higher mean semen volume. CONCLUSIONS: Semen cryopreservation was possible in most adolescent cancer cases regardless of age or diagnosis. In all cases the quality of the semen was potentially useful for assisted conception procedures. An offer to freeze sperm in all patients aged >12 years should be made. Adequate support and counselling of both the boys and their parents is essential.


Asunto(s)
Criopreservación , Neoplasias/terapia , Preservación de Semen , Semen/fisiología , Adolescente , Adulto , Niño , Consejo , Enfermedad de Hodgkin/terapia , Humanos , Leucemia Mieloide Aguda/terapia , Linfoma no Hodgkin/terapia , Masculino , Osteosarcoma/terapia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Sarcoma de Ewing/terapia , Recuento de Espermatozoides , Neoplasias Testiculares/terapia
20.
Hum Reprod ; 17(10): 2654-6, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12351544

RESUMEN

BACKGROUND: The influence of an accompanying person (parent, guardian or nurse) on the ability of an adolescent (post-pubescent, <20 years of age) to produce a semen sample for cryopreservation, is undetermined, as is the potential for use of urine samples to retrieve sperm in those adolescents that are unable to produce a semen sample. METHODS: The records from 1991-2000 inclusive were reviewed to derive those adolescent patients who were unable to produce semen for cryopreservation prior to undergoing treatment for a malignant condition. RESULTS: During the study period 238 adolescents attended our unit of whom 205 (86.1%) banked semen ('producers'). The remaining 33 adolescents (13.9%) were initially unable to produce a sample ('non-producers'), four of these provided a urine specimen for analysis (12.1%) and of these one had sufficient sperm for cryopreservation. Of the 'accompanied' patients 29.7% (19/64) were non-producers while in the 'unaccompanied' patients only 8.0% (14/174) were non-producers (chi(2) = 16.58, P < 0.001). The relative risk (RR) of not producing a semen sample for the accompanied group of patients was greater than that for the unaccompanied group (RR = 3.689, 95% confidence interval: 2.0-6.9). One patient returning alone successfully provided a semen sample for storage. CONCLUSION: Units should consider the effect of the presence of an accompanying person when an adolescent is unable to produce a semen sample and should consider requesting urine to retrieve sperm.


Asunto(s)
Fertilidad , Neoplasias/terapia , Preservación de Semen , Manejo de Especímenes , Adolescente , Criopreservación , Enfermedad de Hodgkin/terapia , Humanos , Infertilidad Masculina/etiología , Leucemia/terapia , Linfoma no Hodgkin/terapia , Masculino , Osteosarcoma/terapia , Estudios Retrospectivos , Sarcoma de Ewing/terapia , Recuento de Espermatozoides , Motilidad Espermática , Orina/citología
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda