Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
J Addict Dis ; : 1-9, 2023 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-37950604

RESUMEN

BACKGROUND: Excessive alcohol drinking negatively affects bone metabolism and leads to a risk of decreased bone mass, which is a major component of the pathogenesis of osteoporosis. However, the potential influence of alcohol on bones has not been fully recognized, particularly among the young to middle-aged generation. OBJECTIVES: This study aimed to investigate the status of serum markers related to bone metabolism in young to middle-aged women with alcohol use disorder (AUD). METHODS: Levels of vitamin D and the bone-resorption marker tartrate-resistant acid phosphatase 5b were measured in the sera of 25 women with AUD (mean age, 39.5 ± 7.5 years) who were enrolled in an AUD rehabilitation program. Data of samples obtained on admission and those after eight weeks were compared. RESULTS: Of the 25 women with AUD, 19 (76%) had vitamin D deficiency (<20 ng/mL), and most of the patients showed relatively higher tartrate-resistant acid phosphatase 5b levels at baseline considering their premenopausal age. Although the levels did not change significantly at week eight of the AUD rehabilitation program, vitamin D levels tended to increase initially in patients with vitamin D deficiency. Although further investigations and detailed nutritional assessment are necessary, the results of this study may support the presence of a relatively unknown influence of AUD on the bone health of the young to middle-aged population. Along with psychological and physical care, persons with AUD should be treated as a high-risk group for future osteoporosis regardless of age.

2.
Pharm Res ; 40(7): 1789-1797, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37253866

RESUMEN

PURPOSE: Cefditoren, the active form of cefditoren pivoxil, is an oral cephalosporin antimicrobial drug. Although cefditoren exhibits high antimicrobial activity against Streptococcus pneumoniae, its pharmacokinetics/pharmacodynamics (PK/PD) characteristics remain unknown. This study aimed to determine its PK/PD parameter with target values for cefditoren against S. pneumoniae in S. pneumoniae lung-infected mice and to simulate MIC range of S. pneumoniae that can be expected to be treated at approved cefditoren doses in human using population pharmacokinetic (PPK) data from patients. METHODS: Susceptibility testing and time-kill assays against S. pneumoniae ATCC® 49619 were performed for in vitro PD evaluation. Based on the results of a PK study in healthy mice and PD studies in S. pneumoniae lung-infected mice, optimal PK/PD parameters were determined using the correlation curve between the PK/PD parameters and lung bacterial count changes. The target value was calculated to achieve a 2 log10 reduction in the lung bacterial counts. RESULTS: In vitro PD evaluation showed that cefditoren had a potent antimicrobial effect against S. pneumoniae in a time-dependent manner at concentrations above the MIC. In PK/PD analyses, both fAUC24/MIC and fCmax/MIC were well correlated with bactericidal efficacy, achieving 2 log10-kill with fAUC24/MIC ≥ 63 and fCmax/MIC ≥ 16. CONCLUSIONS: Cefditoren pivoxil has good therapeutic efficacy against acute pneumonia caused by S. pneumoniae with a MIC ≤ 0.031-0.063 mg/L at approved doses in adults and children.


Asunto(s)
Antiinfecciosos , Neumonía , Infecciones Estafilocócicas , Niño , Humanos , Ratones , Animales , Streptococcus pneumoniae , Infecciones Estafilocócicas/tratamiento farmacológico , Cefalosporinas/farmacología , Cefalosporinas/uso terapéutico , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Pulmón , Antiinfecciosos/farmacología , Pruebas de Sensibilidad Microbiana
3.
Pharm Res ; 38(11): 1839-1846, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34853981

RESUMEN

PURPOSE: Cefmetazole (CMZ) has received attention as a pharmaceutical intervention for extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-EC) infections. This study aimed to investigate the pharmacokinetics/pharmacodynamics (PK/PD) characteristics of CMZ against ESBL-EC. METHODS: The susceptibility and time-killing activity of CMZ against clinically isolated ESBL-EC (EC9 and EC19) were determined in vitro. The optimal PK/PD index and its target value were calculated based on the results of a PK study in healthy mice and PD study in neutropenic murine thigh infection model mice. RESULTS: The minimum inhibitory concentrations (MICs) of CMZ against EC9 and EC19 were 2.0 and 1.0 µg/mL, respectively. Time-kill studies showed that colony-forming units decreased in a time-dependent manner at CMZ concentrations in the range of 4-64 × MIC. In in vivo PK/PD studies, the antibacterial effect of CMZ showed the better correlation with the time that the free drug concentration remaining above the MIC (fT>MIC), with the target values for a static effect and 1 log10 kill reduction calculated as 57.6% and 69.6%, respectively. CONCLUSION: CMZ possesses time-dependent bactericidal activities against ESBL-EC and is required to achieve "fT>MIC" ≥ 69.6% for the treatment of ESBL-EC infections.


Asunto(s)
Antibacterianos/farmacología , Cefmetazol/farmacología , Infecciones por Escherichia coli/tratamiento farmacológico , Neutropenia/tratamiento farmacológico , Animales , Antibacterianos/uso terapéutico , Carbapenémicos/farmacología , Carbapenémicos/uso terapéutico , Cefmetazol/uso terapéutico , Modelos Animales de Enfermedad , Escherichia coli/efectos de los fármacos , Escherichia coli/enzimología , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/metabolismo , Femenino , Humanos , Ratones , Pruebas de Sensibilidad Microbiana , Neutropenia/microbiología , Resistencia betalactámica , beta-Lactamasas/metabolismo
4.
BMC Infect Dis ; 21(1): 153, 2021 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-33549035

RESUMEN

BACKGROUND: This systematic review and meta-analysis explored the relationship between vancomycin (VCM) monitoring strategies and VCM effectiveness and safety. METHODS: We conducted our analysis using the MEDLINE, Web of Sciences, and Cochrane Register of Controlled Trials electronic databases searched on August 9, 2020. We calculated odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Adult patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia with VCM trough concentrations ≥15 µg/mL had significantly lower treatment failure rates (OR 0.63, 95% CI 0.47-0.85). The incidence of acute kidney injury (AKI) increased with increased trough concentrations and was significantly higher for trough concentrations ≥20 µg/mL compared to those at 15-20 µg/mL (OR 2.39, 95% CI 1.78-3.20). Analysis of the target area under the curve/minimum inhibitory concentration ratios (AUC/MIC) showed significantly lower treatment failure rates for high AUC/MIC (cut-off 400 ± 15%) (OR 0.28, 95% CI 0.18-0.45). The safety analysis revealed that high AUC value (cut-off 600 ± 15%) significantly increased the risk of AKI (OR 2.10, 95% CI 1.13-3.89). Our meta-analysis of differences in monitoring strategies included four studies. The incidence of AKI tended to be lower in AUC-guided monitoring than in trough-guided monitoring (OR 0.54, 95% CI 0.28-1.01); however, it was not significant in the analysis of mortality. CONCLUSIONS: We identified VCM trough concentrations and AUC values that correlated with effectiveness and safety. Furthermore, compared to trough-guided monitoring, AUC-guided monitoring showed potential for decreasing nephrotoxicity.


Asunto(s)
Antibacterianos/uso terapéutico , Monitoreo de Drogas/métodos , Vancomicina/uso terapéutico , Lesión Renal Aguda/inducido químicamente , Lesión Renal Aguda/epidemiología , Adulto , Antibacterianos/farmacología , Área Bajo la Curva , Bacteriemia/tratamiento farmacológico , Humanos , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Oportunidad Relativa , Seguridad , Infecciones Estafilocócicas/tratamiento farmacológico , Insuficiencia del Tratamiento , Vancomicina/farmacología
5.
J Infect Chemother ; 27(5): 781-785, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33563525

RESUMEN

We carried out a systematic review and meta-analysis exploring the relationship between vancomycin (VCM) trough concentrations and its effectiveness and nephrotoxicity in pediatric patients. We conducted our analysis using MEDLINE, Web of Sciences, and Cochrane Register of Controlled Trials as electronic databases (June 29, 2019). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. We identified 16 studies that were eligible for the meta-analysis. A total of 351 and 3,266 patients were included in the analysis for effectiveness and nephrotoxicity, respectively. Pediatric MRSA infection patients with VCM trough concentrations ≥ 10 µg/mL had significantly lower treatment failure rates (OR 0.54, 95% CI 0.30-0.96). The incidence of nephrotoxicity was significantly higher in trough concentrations ≥ 15 µg/mL than when they were < 15 µg/mL (OR 3.02, 95% CI 2.08-4.38). We identified the optimal VCM trough concentrations associated with effectiveness and nephrotoxicity in pediatric patients with MRSA infection. Further prospective studies are needed to find optimal dosing and monitoring strategy on VCM in pediatric population.


Asunto(s)
Staphylococcus aureus Resistente a Meticilina , Insuficiencia Renal , Antibacterianos/efectos adversos , Niño , Humanos , Estudios Prospectivos , Estudios Retrospectivos , Vancomicina/efectos adversos
6.
Pharm Res ; 38(1): 27-35, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33404990

RESUMEN

PURPOSE: Although flomoxef (FMOX) has attracted substantial attention as an antibiotic against extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-producing E. coli), the pharmacokinetics/pharmacodynamics (PK/PD) characteristics of FMOX against ESBL-producing E. coli is unclear. The aim of this study was to determine the PK/PD index of FMOX against ESBL-producing E. coli. METHODS: In vitro time-kill curve studies and in vivo PK/PD experiments were carried out. RESULTS: Time-kill curves exhibited a unique bactericidal activity: time-dependent activity at low concentrations and concentration-dependent activity at high concentrations. In neutropenic murine thigh infection experiments, the antibacterial activity of FMOX correlated with the time that the free drug concentration remaining above the minimum inhibitory concentration (MIC) (fT>MIC) and the ratio of the area under the free drug concentration-time curve for a 24 h period to the MIC (fAUC24/MIC). However, the burden of ESBL producing E. coli significantly reduced when the time intervals for administration were shorter among three dosage regimens with same magnitude of fAUC24/MIC, indicating that fT>MIC is significant PK/PD index. The target value of fT>MIC for 1 log10 kill reduction was 35.1%. CONCLUSIONS: fT>MIC is the most significant PK/PD index of FMOX against ESBL-producing E. coli and its target value is ≥ 40%.


Asunto(s)
Cefalosporinas/farmacología , Infecciones por Escherichia coli/tratamiento farmacológico , Escherichia coli/efectos de los fármacos , Animales , Área Bajo la Curva , Cefalosporinas/uso terapéutico , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Escherichia coli/enzimología , Infecciones por Escherichia coli/microbiología , Femenino , Humanos , Ratones , Pruebas de Sensibilidad Microbiana , Resistencia betalactámica/efectos de los fármacos , beta-Lactamasas/metabolismo
7.
Dalton Trans ; 46(47): 16408-16411, 2017 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-29139503

RESUMEN

The treatment of titanacyclopentadienes with bismuth(iii) chloride gave spiro compounds in moderate yields. Two carbon atoms of the diene moiety of the titanacyclopentadiene were connected to one carbon atom of the Cp ligand. This is in sharp contrast to the formation of dihydroindene derivatives, where two carbon-carbon bonds were formed between the diene moiety and the adjacent two carbon atoms of the Cp ligand.

8.
Org Lett ; 18(24): 6217-6219, 2016 12 16.
Artículo en Inglés | MEDLINE | ID: mdl-27978636

RESUMEN

The highly selective synthesis of triene derivatives was achieved by a zirconocene-mediated three-component coupling reaction, and the trienes were efficiently subjected to 7-endo mode cyclization. The reaction of unsymmetrical zirconacyclopentadienes prepared from two different alkynes with N-bromosuccinimide (NBS) followed by treatment with allyl halides in the presence of CuCl afforded the corresponding heptatrienes in good yields. When the trienes reacted with an organolithium reagent, 7-endo mode cyclization occurred smoothly to give the corresponding cycloheptadiene.

9.
Org Lett ; 17(24): 5942-5, 2015 Dec 18.
Artículo en Inglés | MEDLINE | ID: mdl-26629792

RESUMEN

The halogen exchange reaction of aliphatic fluorine compounds with organic halides as the halogen source was achieved. Treatment of alkyl fluorides (primary, secondary, or tertiary fluorides) with a catalytic amount of titanocene dihalides, trialkyl aluminum, and polyhalomethanes (chloro or bromo methanes) as the halogen source gave the corresponding alkyl halides in excellent yields under mild conditions. In the case of a fluorine/iodine exchange, no titanocene catalyst is needed. Only C-F bonds are selectively activated under these conditions, whereas alkyl chlorides, bromides, and iodides are tolerant to these reactions.

10.
Angew Chem Int Ed Engl ; 53(34): 8899-903, 2014 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-24986055

RESUMEN

Titanacyclopentadienes, prepared from [Cp2TiBu2] and either two equivalents of an alkyne or a diyne, were treated with PMe3 (3 equiv) at 50 °C for 3 h and then with azobenzene at room temperature for 12 h to give 4,5,6-trisubstituted indene derivatives with the loss of one substituent in good yields. This reaction contrasts sharply with our previously reported reaction for the formation of 4,5,6,7-tetrasubstituted indene derivatives without the loss of substituents by the treatment of titanacyclopentadienes with azobenzene without PMe3. (13)C NMR spectroscopy of the product derived from a (13)C-enriched complex revealed that the five carbon atoms originating from a Cp ligand were arranged linearly in the trisubstituted indene derivatives, in contrast to the 4,5,6,7-tetrasubsituted indene derivatives, in which the corresponding five carbon atoms are arranged in a ring.


Asunto(s)
Ciclopentanos/química , Titanio/química , Espectroscopía de Resonancia Magnética con Carbono-13 , Ligandos , Estructura Molecular
11.
J Biochem ; 153(1): 121-9, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23100271

RESUMEN

Viperidae snakes containing various venomous proteins also have several anti-toxic proteins in their sera. However, the physiological function of serum protein has been elucidated incompletely. Small serum protein (SSP)-1 is a major component of the SSPs isolated from the serum of a Japanese viper, the habu snake (Trimeresurus flavoviridis). It exists in the blood as a binary complex with habu serum factor (HSF), a snake venom metalloproteinase inhibitor. Affinity chromatography of the venom on an SSP-1-immobilized column identified HV1, an apoptosis-inducing metalloproteinase, as the target protein of SSP-1. Biacore measurements revealed that SSP-1 was bound to HV1 with a dissociation constant of 8.2 × 10⁻8 M. However, SSP-1 did not inhibit the peptidase activity of HV1. Although HSF alone showed no inhibitory activity or binding affinity to HV1, the SSP-1-HSF binary complex bound to HV1 formed a ternary complex that non-competitively inhibited the peptidase activity of HV1 with a inhibition constant of 5.1 ± 1.3 × 10⁻9 M. The SSP-1-HSF complex also effectively suppressed the apoptosis of vascular endothelial cells and caspase 3 activation induced by HV1. Thus, SSP-1 is a unique protein that non-covalently attaches to HV1 and changes its susceptibility to HSF.


Asunto(s)
Apoptosis/efectos de los fármacos , Venenos de Crotálidos/farmacología , Metaloproteasas/metabolismo , Inhibidores de Proteasas/farmacología , Proteínas de Reptiles/farmacología , Trimeresurus/metabolismo , Animales , Caspasa 3/química , Caspasa 3/metabolismo , Células Cultivadas , Venenos de Crotálidos/metabolismo , Endotelio Vascular/citología , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/metabolismo , Humanos , Proteínas Inmovilizadas/metabolismo , Cinética , Metaloproteasas/antagonistas & inhibidores , Metaloproteasas/química , Metaloproteasas/aislamiento & purificación , Modelos Moleculares , Peso Molecular , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Inhibidores de Proteasas/sangre , Inhibidores de Proteasas/química , Inhibidores de Proteasas/metabolismo , Unión Proteica , Proteolisis/efectos de los fármacos , Proteínas de Reptiles/antagonistas & inhibidores , Proteínas de Reptiles/química , Proteínas de Reptiles/metabolismo , Especificidad por Sustrato , Trimeresurus/sangre , Cordón Umbilical/citología
12.
Alcohol Clin Exp Res ; 36(10): 1820-6, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22486539

RESUMEN

BACKGROUND: The biomarkers of excessive alcohol intake reported thus far have not always been reliable. We discovered the presence of free glycerol (FG) by high-performance liquid chromatography (HPLC) in the serum of alcoholic patients but not in healthy persons, and a higher percentage of the alcoholics were positive for serum FG than for gamma-glutamyl transpeptidase, mean corpuscular volume, or carbohydrate-deficient transferrin (%CDT). Therefore, in this study, we investigated whether the same results as with HPLC could be obtained by measuring FG with an easy-to-use autoanalyzer and whether the serum FG measured by this method would be useful as a biomarker of excessive alcohol intake. METHODS: First, the measurements of serum FG made by HPLC and by a biochemical method with an autoanalyzer were tested for a correlation, and then fasting serum FG was measured with the autoanalyzer in 3 groups: a group of Japanese male alcoholics who drank until just before admission, a group of Japanese male patients with chronic viral hepatitis, and a group of Japanese healthy male volunteers. RESULTS: There was a strong positive correlation between the serum FG values measured by HPLC and by the autoanalyzer in the alcoholic group. The values in the alcoholic group were significantly higher than in the viral hepatitis group and healthy control group. We set the cutoff serum FG value for discriminating between the alcoholic group and the other 2 groups in the receiver operating characteristic analysis at 0.9 mg/dl, and that cutoff value provided a sensitivity of 80% for identifying the alcoholic group and a specificity of 84 and 94% in relation to the viral hepatitis group and the healthy volunteer group, respectively. Among various clinical tests in the alcoholic group, serum FG showed the highest rate of abnormally high value. CONCLUSIONS: Measurement of serum FG with an autoanalyzer may be useful as a biomarker of excessive alcohol intake.


Asunto(s)
Alcoholismo/sangre , Alcoholismo/diagnóstico , Glicerol/sangre , Templanza , Adulto , Anciano , Anciano de 80 o más Años , Autoanálisis/métodos , Biomarcadores/sangre , Cromatografía Líquida de Alta Presión , Hepatitis Viral Humana/sangre , Humanos , Masculino , Persona de Mediana Edad
13.
Artículo en Japonés | MEDLINE | ID: mdl-20387541

RESUMEN

Malnutrition and emaciation in alcoholics is associated with various alcoholism-related diseases, including Wernicke's encephalopathy, aero-digestive tract cancer, and serious metabolic disorders. We used a self-administered questionnaire survey for structured dietary habit screening to evaluate the dietary profiles of 467 Japanese alcoholic men aged 40 years or over and their relationship to body mass index (BMI). Their average daily ethanol consumption was 119 +/- 65 g (845 +/- 463 kcal). The survey showed that 50.5% of the subjects consumed three meals a day; 32.8%, two meals; 12.2%, one meal; and 4.5% rarely ate. The meals mainly consisted of carbohydrates and protein, with few vegetables. Daily alcohol consumption was inversely correlated with the frequency of meals, drinking milk, and consuming confectionery. The subjects who lived with their family (72.8%) consumed more meals than the subjects liv- ing alone. After excluding 22 subjects with leg edema or ascites, the average BMI was 21.3 +/- 3.2. The group with the lowest BMI values (<18.5) accounted for 19.3% of the subjects, and those with the highest BMI values (> or = 25) accounted for 11.5%. A multivariate stepwise logistic analysis showed that BMI increased 0.15 per 22 g ethanol consumed daily and decreased 0.03 per + 10 cigarettes smoked daily, 0.43 per decrease by one in daily frequency of meals, and 0.54 per category (daily, occasionally, rarely, seldom) of milk consumption. The likelihood of a low BMI <18.5 was significantly and independently associated with smoking [OR (95%CI) =1.24 (1.02-1.51) per +10 cigarettes] and with intake of seafood [0.62 (0.41-0.94) per +1 category], milk [1.52 (1.16-2.00) per +1 category] and green and yellow vegetables [1.52 (1.05-2.21) per +1 category]. Intervention in regard to diet as well as drinking is important to preventing malnutrition and emaciation in alcoholics.


Asunto(s)
Consumo de Bebidas Alcohólicas , Alcoholismo/fisiopatología , Alcoholismo/psicología , Índice de Masa Corporal , Conducta Alimentaria , Fumar , Adulto , Pueblo Asiatico , Humanos , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios
14.
Artículo en Japonés | MEDLINE | ID: mdl-18516950

RESUMEN

High density lipoprotein (HDL) is increased by exercise and drinking and is well known as a negative risk factor of coronary heart disease. We analyzed serum lipids of alcoholics from the view points of biochemical examination, remnant like particle (RLP) and particle size of lipoprotein for the purpose of estimated effect of serum lipids, especially HDL quality in alcoholics. Serum levels of total cholesterol, free glycerol, RLP-C and RLP-TG were significantly decreased after hospitalization. The condition of RLP-C/RLP-TG on admission revealed cholesterol-rich composition. In case of HDL-C, the longer period from last drinking to hospitalization affected its decrease. From analytical study of particle size of lipoprotein, quantities of HDL-C in very large size and large size were significantly decreased after hospitalization which means that HDL composition at hospitalization is cholesterol-rich. So, it is speculated that increased serum level of HDL in alcoholics may be caused by expanded cholesterol ester and its quality may be different from that of healthy people. In this meaning, the study of arteriosclerosis in alcoholics will be necessary in relation to high level of serum HDL-C.


Asunto(s)
Alcoholismo/metabolismo , Colesterol/metabolismo , Lipoproteínas HDL/metabolismo , Lipoproteínas/metabolismo , Triglicéridos/metabolismo , Arteriosclerosis/etiología , Humanos , Lipoproteínas HDL/sangre , Persona de Mediana Edad , Tamaño de la Partícula
15.
Artículo en Japonés | MEDLINE | ID: mdl-18402054

RESUMEN

The drinking history and current medical history of patients with alcohol dependence were surveyed and they were analyzed by gender, age and changes with time (2 stages). The results showed that in the course of continued habitual drinking by patients with alcohol dependence, a wide range of physical complications occurred. The main complications in men were gastrointestinal diseases and in women were mental and behavioral disorders, showing a gender difference in the medical history. This result suggested that there is a high possibility that this will contribute to early discovery and early measures against alcohol related problems in women, which are difficult to bring out into the open. Better alcohol education including mental health is important from an early age.


Asunto(s)
Alcoholismo/clasificación , Alcoholismo/diagnóstico , Clasificación Internacional de Enfermedades , Anamnesis , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Alcoholismo/complicaciones , Alcoholismo/prevención & control , Diagnóstico Precoz , Femenino , Enfermedades Gastrointestinales/complicaciones , Enfermedades Gastrointestinales/epidemiología , Educación en Salud , Humanos , Masculino , Trastornos Mentales/complicaciones , Trastornos Mentales/epidemiología , Persona de Mediana Edad , Factores Sexuales
16.
Plant Cell ; 16(1): 74-87, 2004 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-14671026

RESUMEN

The aerial parts of the plant are generated by groups of rapidly dividing cells called shoot apical meristems. To analyze cell behavior in these structures, we developed a technique to visualize living shoot apical meristems using the confocal microscope. This method, combined with green fluorescent protein marker lines and vital stains, allows us to follow the dynamics of cell proliferation, cell expansion, and cell differentiation at the shoot apex. Using this approach, the effects of several mitotic drugs on meristem development were studied. Oryzalin (depolymerizing microtubules) very rapidly caused cell division arrest. Nevertheless, both cell expansion and cell differentiation proceeded in the treated meristems. Interestingly, DNA synthesis was not blocked, and the meristematic cells went through several rounds of endoreduplication in the presence of the drug. We next treated the meristems with two inhibitors of DNA synthesis, aphidicolin and hydroxyurea. In this case, cell growth and, later, cell differentiation were inhibited, suggesting an important role for DNA synthesis in growth and patterning.


Asunto(s)
Arabidopsis/crecimiento & desarrollo , Ciclo Celular/fisiología , Diferenciación Celular/fisiología , Meristema/crecimiento & desarrollo , Sulfanilamidas , Afidicolina/farmacología , Arabidopsis/citología , Arabidopsis/genética , Ciclo Celular/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , ADN de Plantas/efectos de los fármacos , ADN de Plantas/genética , Dinitrobencenos/farmacología , Hidroxiurea/farmacología , Meristema/citología , Meristema/efectos de los fármacos , Microscopía Confocal , Inhibidores de la Síntesis del Ácido Nucleico/farmacología , Brotes de la Planta/citología , Brotes de la Planta/crecimiento & desarrollo
17.
Clin Chem ; 48(11): 1946-54, 2002 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12406980

RESUMEN

BACKGROUND: The analytical and clinical performance of homogeneous LDL-cholesterol assays has been reported, but their reactions with subfractions of LDL and VLDL have not been described in detail. METHODS: We evaluated reaction selectivity of two homogeneous LDL-cholesterol assays, LDLk (Kyowa Medex) and LDLd (Daiichi Pure Chemical), with ultracentrifugally isolated VLDL and LDL subfractions to identify the lipoprotein particles from which the cholesterol recognized by these assays originates. RESULTS: The LDLd (y) and LDLk (x) methods correlated highly for whole serum samples: y = 0.986x - 39.5 mg/L (r = 0.966; n = 34). In isolated VLDL, the LDLk and the LDLd methods recovered 17.3% and 23.8% of cholesterol, respectively; but correlation analysis revealed differential reactivity to small and large VLDL particles. For the isolated LDL subfraction of density 1.019-1.040 kg/L, the LDLd method had significantly higher reactivity (95.6-98.7%) than the LDLk (88.4-92.0%). Both methods, however, demonstrated poor recovery (approximately 50%) for the 1.050-1.063 kg/L fraction, indicating incomplete reactivity with small, dense LDL. Reactivity with lipoprotein(a) was better (71.2-90.8%) for both methods than with small LDL. For intermediate-density lipoprotein (IDL), there was no significant difference in recovery between the two methods (71.7% for LDLk and 68.9% for LDLd), but the LDLk method appeared to be more sensitive to IDL particle size. CONCLUSIONS: The two homogeneous assays for LDL-cholesterol demonstrate only partial reactivity to small, dense LDL and nonspecific reactions to VLDL particles. Modification will be required in the homogeneous methods to obtain LDL-cholesterol values equivalent to those obtained by ultracentrifugation.


Asunto(s)
LDL-Colesterol/sangre , VLDL-Colesterol/sangre , Adulto , Anciano , Anciano de 80 o más Años , Cromatografía Líquida de Alta Presión , Humanos , Hiperlipidemias/sangre , Persona de Mediana Edad , Juego de Reactivos para Diagnóstico , Ultracentrifugación
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...