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1.
Mymensingh Med J ; 29(3): 691-700, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32844813

RESUMEN

The aim of the modern dentistry is to provide the predictable treatment in short duration. Replacement of missing teeth in shorter duration helps in fulfilling patient's aesthetics and functional demands. Endosseous dental implants are predictable method for replacing missing dentition. The evolution in implant surgical techniques is focused on decreasing treatment duration, e.g. implants can be placed in fresh extraction socket. Therefore, this non-randomized clinical controlled study was designed to determine that whether the treatment outcomes obtained by short treatment duration (immediate implant) are comparable with conventional treatment options (delayed implant) by evaluating the peri-implant soft and hard tissue level, clinically and radiographically {by Cone beam computed tommography (CBCT)}. Total of 30 implants were placed in 13 patients, according to Type 1 ITI protocol (Group 1; 15 implants) and Type 4 ITI protocol (Group 2; 15 implants). Implants in each group were loaded with definitive restoration after 3 months of placement. Hard tissue parameters (marginal bone width and height and probing depth) and soft tissue parameters (width of keratinised gingiva and papillary index) were evaluated at baseline, 3 months post implant insertion and 3 months post prosthetic loading. The results showed statistically significant reduction in width of marginal bone in delayed implants as compared to immediate implants. In contrast, significant reduction in marginal bone height and width of keratinised gingiva was evident in immediate implants. Significant reduction in pocket depth (after 2nd stage surgery and 3 months post prosthetic loading) was noted around delayed implants (p<0.05). Moreover, esthetic results showed regeneration of interproximal papillae in both the groups till the end of study period. This study was concluded that both the groups showed similar results but in some aspects delayed implants was superior to immediate implants. Careful evaluation of implant placement sites before implant installation promotes optimal implant esthetics and survival outcomes.


Asunto(s)
Prótesis e Implantes , Humanos , Radiografía , Resultado del Tratamiento
2.
Mitochondrial DNA ; 26(1): 92-100, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24041451

RESUMEN

Identification of elasmobranchs by conventional taxonomy is difficult due to similarities in morphological characters. Species-specific molecular markers are good choice for identifying species irrespective of it's life stage. Recently, mitochondrial cytochrome c oxidase subunit I (COI) gene got global recognition as a barcode gene to discriminate all animals up-to species level. In this study, mitochondrial COI partial gene was used to develop DNA barcodes for 18 species of elasmobranchs (10 species of sharks and 8 species of rays). The COI barcodes clearly distinguished all the species with high interspecific distance values than intraspecific values. The average interspecific and intraspecific distance values are 8.6% and 0.3% for sharks, respectively and 12.4% and 0.63% for rays, respectively using K2P method. The Neighbor-Joining tree showed distinct clusters shared by the species of same genera. The COI barcodes were also used to estimate allopatric divergences for selected species across broad geographical locations and found that Sphyrna lewini, Aetobatus narinari and Neotrygon kuhlii have cryptic diversity.


Asunto(s)
Código de Barras del ADN Taxonómico , Elasmobranquios/clasificación , Elasmobranquios/genética , Complejo IV de Transporte de Electrones/genética , Genes Mitocondriales , Animales , Composición de Base , Complejo IV de Transporte de Electrones/química , Variación Genética , India , Filogenia , Filogeografía , Análisis de Secuencia de ADN
3.
Mol Biol Rep ; 41(1): 447-57, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24293104

RESUMEN

The elasmobranchs (sharks, rays and skates) being the extant survivors of one of the earliest offshoots of the vertebrate evolutionary tree are good model organisms to study the primitive vertebrate conditions. They play a significant role in maintaining the ecological balance and have high economic value. Due to over-exploitation and illegal fishing worldwide, the elasmobranch stocks are being decimated at an alarming rate. Appropriate management measures are necessary for restoring depleted elasmobranch stocks. One approach for restoring stocks is implementation of conservation measures and these measures can be formulated effectively by knowing the evolutionary relationship among the elasmobranchs. In this study, a total of 30 species were chosen for molecular phylogeny studies using mitochondrial cytochrome c oxidase subunit I, 12S ribosomal RNA gene and nuclear Internal Transcribed Spacer 2. Among different genes, the combined dataset of COI and 12S rRNA resulted in a well resolved tree topology with significant bootstrap/posterior probabilities values. The results supported the reciprocal monophyly of sharks and batoids. Within Galeomorphii, Heterodontiformes (bullhead sharks) formed as a sister group to Lamniformes (mackerel sharks): Orectolobiformes (carpet sharks) and to Carcharhiniformes (ground sharks). Within batoids, the Myliobatiformes formed a monophyly group while Pristiformes (sawfishes) and Rhinobatiformes (guitar fishes) formed a sister group to all other batoids.


Asunto(s)
Elasmobranquios/genética , Genes Mitocondriales , Animales , Composición de Base , Teorema de Bayes , ADN Espaciador Ribosómico/genética , Complejo IV de Transporte de Electrones/genética , Proteínas de Peces/genética , Marcadores Genéticos , Funciones de Verosimilitud , Modelos Genéticos , Tipificación de Secuencias Multilocus , Filogenia , ARN Ribosómico/genética , Análisis de Secuencia de ADN
4.
Eur Neuropsychopharmacol ; 22(2): 92-9, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21733663

RESUMEN

There is a potential risk that 5-HT(1A) receptor blockade combined with blockade of the 5-HT transporter by an SSRI may cause a toxic increase in 5-HT within the synapse, sparking concern for 'serotonin syndrome', a rare but potentially life threatening condition. We evaluated the safety and pharmacodynamics of the combination of the 5-HT(1A) antagonist lecozotan and the SSRI citalopram in a well-controlled Clinical Pharmacology Unit setting using the Hunter Serotonin Toxicity Criteria (HSTC), a set of validated decision rules featuring neurological and body temperature measurements, to detect any clinically relevant serotonin toxicity. Forty-three young healthy male subjects were randomized, to 2 parallel double-blind treatment groups following a 10-day citalopram 40 mg run-in period: citalopram 40 mg/lecozotan 10mg or citalopram 40 mg/placebo for 9 days. Overall, the combined administration of active drugs was well tolerated, however, one subject experienced moderate hyperreflexia, tremor of the hands, and sweating of hands and feet after 3 days of combined treatment. The event prompted treatment withdrawal and was regarded as mild serotonin toxicity, as per the HSTC. The onset of the event was around the time of peak plasma concentrations (t(max)) of both lecozotan and citalopram, and its time course corresponds to the well-defined PK profile of lecozotan. No evidence of a PK interaction was detected trough lecozotan and citalopram plasma concentrations analysis. The utility of the HSTC in detecting the non-discrete group of symptoms commonly referred to as "serotonin toxicity" was demonstrated in this clinical pharmacology study combining two 5-HT agents in a clinically controlled setting.


Asunto(s)
Temperatura Corporal/efectos de los fármacos , Receptor de Serotonina 5-HT1A/metabolismo , Proteínas de Transporte de Serotonina en la Membrana Plasmática/metabolismo , Síndrome de la Serotonina/diagnóstico , Síndrome de la Serotonina/fisiopatología , Adulto , Citalopram/administración & dosificación , Citalopram/sangre , Estudios Cruzados , Dioxanos/administración & dosificación , Dioxanos/sangre , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Esquema de Medicación , Interacciones Farmacológicas , Electroencefalografía/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Examen Neurológico , Piperazinas/administración & dosificación , Piperazinas/sangre , Antagonistas del Receptor de Serotonina 5-HT1/administración & dosificación , Antagonistas del Receptor de Serotonina 5-HT1/sangre , Síndrome de la Serotonina/inducido químicamente , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
5.
Clin Pharmacol Ther ; 83(1): 86-96, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17507923

RESUMEN

This positron emission tomography (PET) study was conducted to assess binding of lecozotan, a new potent and silent 5-hydroxytryptamine-1A (5-HT1A) antagonist being developed for the treatment of Alzheimer's disease (AD), to 5-HT1A receptors in the human brain using 11C-labeled WAY-100635. Lecozotan was administered as a single dose of 0.5, 1, or 5 mg to young subjects and 5 mg to elderly subjects and AD patients. PET measurements were performed at 3-4 time points over a 25-h period. Mean peak 5-HT1A receptor occupancy (RO) in young subjects (seen at 1 h) was 10%, 18%, and 44% for the three doses, respectively. Mean peak RO was slightly higher in elderly (63%) and AD patients (55%). An Emax pharmacokinetic/pharmacodynamic model adequately described the lecozotan plasma concentration-RO relationship. Steady-state peak RO is predicted to be approximately 70% for 5 mg q12 h (twice-daily). Results demonstrate that lecozotan binds to the human brain 5-HT1A receptors and has a maximum observed RO of 50-60% following a single dose of 5 mg in elderly subjects/AD patients.


Asunto(s)
Envejecimiento/metabolismo , Enfermedad de Alzheimer/metabolismo , Encéfalo/metabolismo , Dioxanos/metabolismo , Piperazinas/metabolismo , Tomografía de Emisión de Positrones , Receptor de Serotonina 5-HT1A/metabolismo , Antagonistas de la Serotonina/metabolismo , Administración Oral , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Encéfalo/efectos de los fármacos , Radioisótopos de Carbono , Simulación por Computador , Dioxanos/administración & dosificación , Dioxanos/efectos adversos , Dioxanos/farmacocinética , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Biológicos , Piperazinas/administración & dosificación , Piperazinas/efectos adversos , Piperazinas/farmacocinética , Unión Proteica , Piridinas , Radiofármacos , Antagonistas del Receptor de Serotonina 5-HT1 , Antagonistas de la Serotonina/administración & dosificación , Antagonistas de la Serotonina/efectos adversos , Antagonistas de la Serotonina/farmacocinética , Factores de Tiempo
6.
Biomark Insights ; 2: 197-217, 2007 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-19662204

RESUMEN

Improvement of high yielding, disease resistant silkworm strains became imminent to increase production of silk, which is a major revenue earner for sericulturists. Since environment interacts with phenotype, conventional breeding did not result in commendable yield improvement in synthetic strains of silkworm, Bombyx mori. Identification of DNA markers associated with different economically important biomass traits and its introgression could assist molecular breeding and expression of stabilized high yielding characters, but genetic basis of most quantitative traits in silkworm is poorly understood due to its polygenic control. Correlation analysis (R = 0.9) revealed significant interrelation among biomass traits viz., larval duration (TLD), larval weight (LWT), cocoon weight (CWT), shell weight (SWT), shell ratio (SR) and floss content. PCR using inter simple sequence repeat (ISSR) primers revealed 92% polymorphism among 14 tropical and temperate strains of B. mori, with average diversity index of 0.747. Stepwise multiple regression analysis (MRA) selected 35 ISSR markers positively or negatively correlated with different biomass traits, illustrated polygenic control. ISSR marker 830.8(1050bp) was significantly associated with LWT, CWT, SWT, SR and floss content, indicated its pleiotropic role. Two ISSR markers, 835.5(1950bp) and 825.9(710bp) showed significant association with floss content and TLD. These markers were segregated in F(2) generation and Chi-square test confirmed (chi(2) = ~45; P < 0.05) its genetic contribution to the associated biomass traits. Strains, with both positively and negatively correlated markers, had intermediate mean value for biomass traits (eg. SWT = 0.17 +/- 0.014 g in GNM and Moria) indicated interaction of loci in natural populations. Low yielding Indian strains grouped together by Hierarchical clustering. Chinese and Japanese strains were distributed in the periphery of ALSCAL matrix indicated convergence of genetic characters in Indian strains. Average genetic distance between Chinese strains and Indian strains (0.193) significantly (P < 0.01) varied from that between Chinese and Japanese strains. Interaction of loci and allelic substitutions induced phenotypic plasticity in temperate B. mori populations on tropic adaptation in India. These outcomes show possibility to combine favorable alleles at different QTL to increase larval, cocoon and shell weight.

7.
Indian J Physiol Pharmacol ; 50(1): 73-8, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16850907

RESUMEN

A clinical mercury sphygmomanometer was used to measure Maximal Expiratory Pressure (MEP) in 29 boys (mean age 8 +/- 1.4 yr) and 21 girls (mean age 7.6 +/- 1.5 yr) of a village in interior Maharashtra. The values of 70.6 +/- 13.4 mmHg SD for the boys and 61.9 +/- 18.9 mmHg for the girls were quite comparable to the respiratory pressures reported elsewhere in literature, even though the subjects were apparently poorly nourished. There was no statistical difference between the MEPs of boys and girls. The MEP was positively and significantly (P<0.01) correlated to height (r=0.51) and weight (r=0.05) in the boys. The MEP denoting respiratory muscle strength also correlated positively with handgrip power used to represent non-respiratory muscle strength (r=0.34) (P>0.05). The simple, reproducible method of measuring MEP as described may be useful for measuring this important physiological parameter at the bedside in children whose respiratory muscle function needs to be evaluated.


Asunto(s)
Desnutrición/fisiopatología , Respiración , Músculos Respiratorios/fisiopatología , Población Rural , Niño , Femenino , Humanos , India , Masculino , Espirometría/métodos
8.
Indian J Physiol Pharmacol ; 49(1): 8-18, 2005 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15881854

RESUMEN

Peak expiratory flow rate is an effective measure of effort dependent airflow. It is relatively a simple procedure, and may be carried out in the field using portable instruments. The average PEFR of healthy young Indian males and females is around 500 and 350 lpm respectively. The PEFR reaches a peak at about 18-20 years, maintains this level up to about 30 years in males, and about 40 years in females, and then declines with age. Common regression equations for Indians enveloping major studies from various parts of the country have been formulated. Indian PEFR values compare favourably with other ethnic groups such as Americans and Europeans.


Asunto(s)
Ápice del Flujo Espiratorio/fisiología , Mecánica Respiratoria/fisiología , Humanos , India/etnología , Pruebas de Función Respiratoria/métodos , Espirometría/métodos
9.
Indian J Physiol Pharmacol ; 49(3): 257-70, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16440843

RESUMEN

Spirometry has been used in India since 1929 to evaluate vital capacity. The mean value for this parameter has changed slightly for the better over about eight decades. It is currently recorded at about 21.8 ml/cm height for males and about 18 ml/cm height for females, the difference between the two sexes being statistically significant throughout the period studied. The vital capacity reaches its peak at about 30 years of age in both Indian men and women and declines there after. There is no significant statistical difference in the vital capacities of subjects from different regions of India. Composite regressions have been generated for use as reference equations for estimating. Vital capacity of Indians is lower than that of Caucasians, but the age related decline is much greater for Caucasians.


Asunto(s)
Pulmón/fisiología , Espirometría , Capacidad Vital/fisiología , Factores de Edad , Femenino , Humanos , India/etnología , Masculino , Reproducibilidad de los Resultados , Mecánica Respiratoria/fisiología , Factores Sexuales , Espirometría/normas , Espirometría/estadística & datos numéricos , Población Blanca
10.
Indian J Physiol Pharmacol ; 48(1): 31-40, 2004 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15270367

RESUMEN

We hypothesized that cerebral dominance may contribute to differences in cardio-vascular responses of right-handers (RH) and left-handers (LH) to autonomic stressors. We tested this hypothesis by exposing 14 RH, and 14 LH males to category I tests in which the hand and cerebral cortex were involved in performing the test viz.--i) Cold pressor test (CPT), ii) Handgrip dynamometry (HGD) and; category II (no use of hand)--i) Orthostatic Tolerance Test (OTT), ii) Valsalva Manuever (VM), iii) Controlled Breathing Test for sinus arrhythmia (SA) in a random sequence, and measured their heart rate (HR/min) and blood pressure (MAP mmHg). All subjects had similar resting HR and MAP values, and responded to the category I interventions with increased HR and BP. The absolute HR values of LH and RH did not differ significantly during the interventions. However, the increase in HR from control induced by the CPT, and the HGD was greater for LH (P<0.05). Also, LH showed a greater decrease in HR and MAP in the recovery phase (P<0.05). The VAS scores for degree of discomfort during the CPT were similar for both the groups. During the OTT, the increase in HR was more in RH (P<0.05). The Valsalva ratios for LH and RH were similar. Our findings suggest that the autonomic control over the cardio-vascular system may be different in LH and RH, and that this imbalance could be attributable to a variation in cerebral dominance.


Asunto(s)
Sistema Nervioso Autónomo/fisiopatología , Presión Sanguínea/fisiología , Lateralidad Funcional/fisiología , Frecuencia Cardíaca/fisiología , Estrés Psicológico/fisiopatología , Adulto , Frío , Femenino , Fuerza de la Mano/fisiología , Humanos , Hipotensión Ortostática/fisiopatología , Masculino , Dimensión del Dolor , Postura/fisiología , Presión , Respiración , Maniobra de Valsalva
11.
J Pharm Sci ; 90(10): 1540-52, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11745712

RESUMEN

Previous in vitro studies evaluating the permeability of enaminones suggested that their blood-brain barrier (BBB) transport might be influenced by the presence of an efflux mechanism. Therefore, transport mechanisms responsible for these anticonvulsants across the BBB were examined. The transport of enaminones (1 x 10(-4) M) were evaluated over 120 min with verapamil (50 microM) and probenecid (100 microM) using bovine brain microvessel endothelial cells (BBMECs) to assess the role of multidrug resistant (MDR) transport proteins [i.e., P-glycoprotein (Pgp) and MDR protein 1 (MRP1)] on efflux, respectively. Uptake studies in the presence and absence of rhodamine 123 (R123; 3.2 and 5.0 microM) were also performed in a Pgp overexpressing cell line, MCF-7/Adr. Select enaminone esters (12.5 mg/kg) were administered intravenously to mdr 1 a/b (+/+), mdr 1 a/b (-/-) knockout and probenecid pretreated mice (20 +/- 5g). Enaminones and R123 were assayed with validated ultraviolet and fluorescence high-performance liquid chromatography methods, respectively. Verapamil and probenecid significantly ( p>0.05) inhibited the transport of select enaminone esters across BBMECs. Two enaminones caused a statistically significant increase in the uptake of R123 in MCF-7/Adr cells. Concentrations of select enaminones in mdr 1 a/b (-/-) mice brains were significantly higher ( p<0.05) compared with those in mdr 1 a/b (+/+) mice brains; however, no differences were observed in probenecid pretreated animals. Taken together, these results strongly suggest that Pgp may influence enaminone transport at the BBB and hence affect epilepsy treatment with these agents.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/fisiología , Compuestos de Anilina/farmacocinética , Anticonvulsivantes/farmacocinética , Barrera Hematoencefálica/fisiología , Ciclohexanonas/farmacocinética , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/fisiología , Compuestos de Anilina/administración & dosificación , Compuestos de Anilina/metabolismo , Animales , Anticonvulsivantes/administración & dosificación , Anticonvulsivantes/metabolismo , Transporte Biológico Activo , Encéfalo/irrigación sanguínea , Encéfalo/metabolismo , Capilares/metabolismo , Bovinos , Ciclohexanonas/administración & dosificación , Ciclohexanonas/metabolismo , Endotelio Vascular/metabolismo , Humanos , Inyecciones Intravenosas , Masculino , Ratones , Ratones Noqueados , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/fisiología , Probenecid/antagonistas & inhibidores , Probenecid/farmacología , Rodamina 123/farmacocinética , Distribución Tisular , Células Tumorales Cultivadas , Verapamilo/farmacología
12.
Eur J Pharm Biopharm ; 52(2): 145-50, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11522479

RESUMEN

Zonula occludens toxin (Zot), a protein elaborated from Vibrio cholerae, has been shown to be capable of reversibly opening tight junctions between intestinal cells The objective of this study was to examine the effect of Zot on the flux of various molecules across Caco-2 cell monolayers. In addition, the transport of a series of anticonvulsants, the enaminones was also evaluated in the presence of Zot. The flux of [(14)C]mannitol, [(14)C]inulin and various enaminones across Caco-2 cell monolayers (n=6) was examined after pre-incubation for 1h with Zot (0 or 4000ng/ml) or phosphate-buffered saline (PBS). At the end of the incubation period, the flux of radiolabeled compounds or enaminones (1x10(-4)M) was assessed over a 2-h period. In addition, dose-response studies with Zot (0, 1000, 2000 or 4000ng/ml) were performed using mannitol. The flux of both mannitol and inulin significantly increased (P<0.05) in the presence of Zot. The transport of the enaminones with Zot ranged from 9.42 to 26.83x10(-5)cm/s vs. 4.68 to 13.83x10(-5)cm/s without Zot. Zot significantly increased the transport of all agents tested. This suggests that the co-administration of drugs with Zot may be a useful delivery strategy to increase the intestinal permeability and hence oral absorption of poorly bioavailable agents.


Asunto(s)
Anticonvulsivantes/farmacocinética , Células CACO-2/metabolismo , Toxina del Cólera/farmacocinética , Uniones Estrechas/metabolismo , Anticonvulsivantes/administración & dosificación , Anticonvulsivantes/química , Técnicas de Cultivo de Célula/métodos , Toxina del Cólera/administración & dosificación , Diuréticos Osmóticos/administración & dosificación , Diuréticos Osmóticos/farmacocinética , Endotoxinas , Humanos , Absorción Intestinal/efectos de los fármacos , Absorción Intestinal/fisiología , Inulina/administración & dosificación , Inulina/farmacocinética , Manitol/administración & dosificación , Manitol/farmacocinética , Peso Molecular , Uniones Estrechas/efectos de los fármacos
13.
Lab Anim (NY) ; 30(8): 50-2, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11910417

RESUMEN

The authors discuss the role of the Environmental Enrichment Committee in developing, implementing, assessing, and modifying a university animal enrichment program.


Asunto(s)
Bienestar del Animal , Guías como Asunto , Vivienda para Animales , Animales , Ambiente , Indiana , Política Organizacional , Desarrollo de Programa , Universidades
14.
Lab Anim (NY) ; 29(8): 31-2, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11381233

RESUMEN

Group housing guinea pigs can save space and money, while improving housing standards. The authors describe enclosure design, enrichments, and husbandry techniques that facilitate group housing female guinea pigs.

15.
J Laryngol Otol ; 113(7): 666-9, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10605567

RESUMEN

The surgical management of Menière's disease presents a difficult and controversial problem and includes various procedures ranging from 'placebo operations' to vestibular nerve section. The situation is even more complex in the case where the only hearing ear is affected. We present a case of severe debilitating vertigo due to Menière's disease that was treated by chemical labyrinthectomy and cochlear implantation. This unique management strategy allowed restoration of useful hearing and relief of vertigo.


Asunto(s)
Implantación Coclear , Oído Interno/efectos de los fármacos , Pérdida Auditiva Sensorineural/cirugía , Enfermedad de Meniere/cirugía , Audiometría de Tonos Puros , Terapia Combinada , Femenino , Gentamicinas , Pérdida Auditiva Sensorineural/fisiopatología , Humanos , Enfermedad de Meniere/fisiopatología , Persona de Mediana Edad , Resultado del Tratamiento
16.
Hum Gene Ther ; 10(6): 889-98, 1999 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-10223723

RESUMEN

The lineage-specific human tyrosinase promoter has been used to successfully target gene expression at the transcriptional level to melanoma cells. The tyrosinase promoter, alone and in combination with a single, or a dual, tandem melanocyte-specific enhancer, was used to regulate expression of the firefly luciferase reporter gene. Transient transfections of these tissue-specific luciferase constructs in human and murine melanoma (Pmel, B16mel) and colon carcinoma (WiDr, MC38) cell lines resulted in melanoma-specific luciferase expression that was amplified 5- and 500-fold with the addition of a single or double enhancer, respectively, to the tyrosinase promoter. When the double enhancer-promoter construct expressed the highly toxic Escherichia coli purine nucleoside phosphorylase (PNP) gene, transfection of the same cell lines followed by administration of the prodrug 6-methyl purine deoxyriboside (6-MPDR) at a concentration of 50 microM caused melanoma-specific in vitro cell killing. Within 5 days after prodrug administration methylthiazol-tetrazolium (MTT) cytotoxicity assays showed that only 15 and 9% of Pmel and B16mel cells, respectively, remained viable compared with controls. This effect was highly specific, as 90 and 96% of WiDr and MC38 colon carcinoma cells remained viable 5 days after identical treatment. This effect was a direct result of increased tissue-specific conversion of 6-MPDR to the toxic metabolite 6-methylpurine (6-MP), as documented by HPLC analysis of culture supernatants. These results show that the dual tandem melanocyte-specific enhancer provides powerful amplification of the transcriptional targeting of gene expression afforded by use of the tyrosinase promoter. This amplification translates into increased, highly specific cytotoxicity to melanoma by the PNP/6-MPDR enzyme/prodrug system and, therefore, has potential efficacy in the use of gene therapy for the treatment of metastatic melanoma.


Asunto(s)
Elementos de Facilitación Genéticos , Regulación Neoplásica de la Expresión Génica , Melanoma Experimental/genética , Purina-Nucleósido Fosforilasa/genética , Animales , Secuencia de Bases , Supervivencia Celular/genética , Citomegalovirus/genética , Cartilla de ADN , Humanos , Melanocitos/metabolismo , Melanoma Experimental/patología , Ratones , Monofenol Monooxigenasa/genética , Regiones Promotoras Genéticas , Nucleósidos de Purina/metabolismo , Regulación hacia Arriba
17.
Antimicrob Agents Chemother ; 43(3): 647-50, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10049281

RESUMEN

The effects of multiple opportunistic infection medications on stavudine pharmacokinetics were evaluated. Ten patients with CD4 counts of less than 200 cells/mm3 received stavudine (40 mg twice daily) in combination with one to three other drugs used to treat opportunistic infections. Serial blood samples for stavudine concentrations were collected after 1 week of therapy on each regimen and assayed for stavudine by using a validated high-pressure liquid chromatography method. Although the maximum concentration of drug in serum was significantly decreased when the drug was given in combination with three opportunistic infection medications, the area under the concentration-time curve did not significantly differ across various treatment regimens. Stavudine exposure was not significantly altered by multiple concomitant medications. Side effects were minor throughout the 3-month study period. The tolerability of stavudine, combined with its lack of drug interactions, makes it an attractive agent for use as part of a combination regimen.


Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/tratamiento farmacológico , Fármacos Anti-VIH/efectos adversos , Antiinfecciosos/efectos adversos , Infecciones por VIH/tratamiento farmacológico , Estavudina/efectos adversos , Adulto , Fármacos Anti-VIH/farmacocinética , Fármacos Anti-VIH/uso terapéutico , Antiinfecciosos/farmacología , Antiinfecciosos/uso terapéutico , Área Bajo la Curva , Interacciones Farmacológicas , Femenino , Humanos , Masculino , Cooperación del Paciente , Estavudina/farmacocinética , Estavudina/uso terapéutico
18.
J Pharm Sci ; 88(1): 121-5, 1999 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9874712

RESUMEN

Thalidomide, a glutamic acid derivative, has recently been shown to inhibit in vitro angiogenesis, the process of formation of new blood vessels. This Phase II study examined the pharmacokinetics of thalidomide in patients with clinically progressive hormone-refractory prostate cancer. Patients (aged 55 to 80 years) were randomized to two different arms, low dose versus high dose. Patients in the low-dose group were given 200 mg of thalidomide and patients in the high-dose group received 200 mg of thalidomide, with subsequent dose escalations to 1200 mg. Serial serum or blood samples were obtained for pharmacokinetic assessment after administration of a single oral dose or multiple daily dosing of thalidomide and were assayed by reversed-phase HPLC. Pharmacokinetic parameters for both the single and multiple dosing were calculated with ADAPT II. A one-compartment model best fit the data. After single dosing, the oral clearance and apparent volume of distribution for the low-dose regimen (n = 13) were 7.41 +/- 2.05 L/h and 66.93 +/- 34.27 L, respectively, whereas for the high-dose regimen (n = 11), these values were 7.21 +/- 2.89 L/h and 165.81 +/- 84.18 L, respectively. The elimination half-lives for the low and high dose were 6.52 +/- 3.81 and 18.25 +/- 14.08 h, respectively. After the multiple dosing of thalidomide, the oral clearance and apparent volume of distribution for the low-dose group (n = 10) were 6.35 +/- 1.64 L/h and 64.63 +/- 23.20 L, respectively, whereas for the high-dose group (n = 11), these values were 7.73 +/- 2.27 L/h and 167.85 +/- 82.08 L, respectively. The elimination half-lives for the low and high dose were 7.08 +/- 1.87 and 16.19 +/- 9.57 h, respectively. For both the single and multiple dosing of thalidomide, the apparent volume of distribution and half-life were significantly higher for the high-dose group than those for the low-dose group. The higher apparent volume of distribution may be attributable to several factors, such as change in absorption, protein binding, etc. A dose-proportional increase in thalidomide steady-state concentrations was seen after multiple daily dosing of thalidomide.


Asunto(s)
Neoplasias de la Próstata/metabolismo , Talidomida/farmacocinética , Anciano , Anciano de 80 o más Años , Área Bajo la Curva , Cromatografía Líquida de Alta Presión , Semivida , Humanos , Masculino , Unión Proteica , Espectrofotometría Ultravioleta
19.
Pharmacotherapy ; 18(6): 1212-6, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9855318

RESUMEN

STUDY OBJECTIVE: To evaluate the effect of interleukin-2 (IL-2) infusions on the pharmacokinetics of indinavir in patients infected with the human immunodeficiency virus. DESIGN: Observational, noncontrolled trial and prospective, open-label, nonrandomized, pharmacokinetic study. SETTING: Government research hospital. PATIENTS: Seventeen patients receiving indinavir 800 mg every 8 hours and a 5-day continuous infusion of recombinant IL-2. INTERVENTIONS: Observational study: trough indinavir concentrations were measured on day 1 and day 5 of IL-2 as part of a clinical trial. Prospective study: serial plasma samples were collected on days 1 and 5 of IL-2 to determine indinavir concentrations. Samples were also collected over the study period to determine IL-6 concentrations. The data were fit by a one-compartment model that allowed clearance to change based on IL-6 production and by standard noncompartmental equations. MEASUREMENTS AND MAIN RESULTS: The area under the curve of indinavir increased in eight of nine patients by a mean of 88% (range -29-215%) between days 1 and 5 of IL-2 infusion. Over this period, IL-6 concentrations also increased in all patients and indinavir clearance significantly decreased. Observational data in eight patients from the clinical trial showed significantly increased indinavir trough concentrations from 264+/-493 to 670+/-677 ng/ml in the presence of IL-2. CONCLUSION: Indinavir concentrations were altered during IL-2 infusions, possibly by induction of IL-6. Investigation into the effects of other proinflammatory cytokines is warranted.


Asunto(s)
Fármacos Anti-VIH/farmacocinética , Infecciones por VIH/tratamiento farmacológico , Indinavir/farmacocinética , Interleucina-2/uso terapéutico , Adulto , Fármacos Anti-VIH/uso terapéutico , Área Bajo la Curva , Quimioterapia Combinada , Femenino , Humanos , Indinavir/sangre , Indinavir/uso terapéutico , Infusiones Intravenosas , Interleucina-2/administración & dosificación , Interleucina-6/sangre , Masculino , Persona de Mediana Edad
20.
Clin Cancer Res ; 4(10): 2357-62, 1998 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9796965

RESUMEN

Isolated organ perfusion of the liver or extremity with tumor necrosis factor (TNF) and melphalan results in regression of bulky tumors in the majority of patients. The efficacy of TNF in this setting is not known, although data suggest that it may exert antitumor effects primarily on tumor-associated neovasculature. We studied the effects of TNF on capillary leak in liver and tumor tissue during isolated hepatic perfusion (IHP) with melphalan. Twenty-seven patients with unresectable cancer confined to the liver underwent a 60-min hyperthermic IHP using 1.5 mg/kg melphalan alone (n = 7) or with 1.0 mg of TNF (n = 20). Complete vascular isolation was confirmed in all patients using an intraoperative leak monitoring I-131 radiolabeled albumin technique. Samples of tumor and liver were collected just prior to and immediately after IHP. There was no difference in I-131 radiolabeled cpm/g of tissue (cpm) in liver versus tumor at baseline (P2 = 0.44). After IHP, I-131 albumin cpm were higher in tumor versus liver (10,999 +/- 1,976 versus 3,821 +/- 780, respectively; P2 < 0.005). However, I-131 albumin cpm in tumor were not effected by TNF (11,636 +/- 2,518 with TNF versus 9,180 +/- 2,674 without TNF; P2 = 0.59). TNF did not affect melphalan concentrations in tumor (1,883 +/- 540 ng/g versus 1,854 +/- 861 ng/g without TNF; P2 = 0.9). Capillary leak, as reflected by diffusion of I-131 radiolabeled albumin into the interstitial space, is comparable in liver and tumor before IHP but is significantly higher in tumor after IHP. The increased diffusion in the capillary tumor bed must occur through TNF-independent mechanisms such as intrinsic features of tumor neovasculature, hyperthermia, or other unrecognized perfusion-related factors. These data indicate that TNF must continue to be critically evaluated in clinical trials before it is routinely used with melphalan in isolated organ perfusion.


Asunto(s)
Permeabilidad Capilar/efectos de los fármacos , Quimioterapia del Cáncer por Perfusión Regional , Neoplasias Hepáticas/tratamiento farmacológico , Factor de Necrosis Tumoral alfa/farmacología , Adulto , Anciano , Femenino , Humanos , Radioisótopos de Yodo , Neoplasias Hepáticas/irrigación sanguínea , Masculino , Melfalán/administración & dosificación , Persona de Mediana Edad , Factor de Necrosis Tumoral alfa/administración & dosificación
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