RESUMEN
Even though conventional chemotherapeutic management of cancer has reduced morbidity and mortality to a great extent, virtually all chemotherapeutic agents cause damage to healthy cells, necessitating exploration of novel anticancer agents that exert their effects through an alternate mode of action. Objectives of our research were twofold. First, we explored the promising potential of histone deacetylase inhibitor sulforaphane for epigenetic therapy for cancer as this therapeutic approach aims to reverse aberrant epigenetic modifications that affect gene expression. In vitro cell culture studies performed using B16 and S91 melanoma cells showed that sulforaphane inhibited growth and proliferation of cancer cells by downregulating deacetylation enzymes. The second part of our research investigated polymeric drug delivery systems to increase therapeutic efficacy and to minimize potential side effects of R,S-sulforaphane. Albumin microspheres encapsulating sulforaphane were developed by spray drying. Microspheres were characterized for their morphology, size and zeta potential. Cell culture studies using melanoma cells and in vivo studies in melanoma tumor-bearing C57BL/6 mice demonstrated that albumin based polymeric delivery system was efficacious and has the potential to enhance the therapeutic effect and anticancer activity of sulforaphane.
Asunto(s)
Antineoplásicos/farmacología , Portadores de Fármacos , Epigénesis Genética/efectos de los fármacos , Inhibidores de Histona Desacetilasas/farmacología , Melanoma Experimental/tratamiento farmacológico , Tiocianatos/farmacología , Albúminas/química , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/química , Antineoplásicos/metabolismo , Transporte Biológico , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Química Farmacéutica , Composición de Medicamentos , Inhibidores de Histona Desacetilasas/administración & dosificación , Inhibidores de Histona Desacetilasas/química , Inhibidores de Histona Desacetilasas/metabolismo , Isotiocianatos , Melanoma Experimental/enzimología , Melanoma Experimental/genética , Melanoma Experimental/patología , Ratones , Ratones Endogámicos C57BL , Microesferas , Tamaño de la Partícula , Solubilidad , Sulfóxidos , Propiedades de Superficie , Tecnología Farmacéutica/métodos , Tiocianatos/administración & dosificación , Tiocianatos/química , Tiocianatos/metabolismo , Factores de Tiempo , Carga Tumoral/efectos de los fármacosRESUMEN
AIM: The present study was directed on the assessment of the response of treatment-naive oral cancer cells to methotrexate (MTX) in vitro: and clinical response to MTX therapy. METHODS: A pilot study of in vitro: evaluation of MTX response of oral cancer cells from 10 patients was conducted using a cell viability assay to determine the sensitivity/resistance to MTX. Quantitative in vitro: data were correlated to the clinical outcome to MTX therapy. RESULTS: A positive correlation was observed between the effect of MTX on tumor cells in vitro: and clinical response for 7 out of 10 patients. CONCLUSIONS: Observations from the proof-of-principle pilot study suggests that oral cancer cells have intrinsically variable response to MTX. Confirmation of these findings with a larger cohort of patients could aid in the development of individualized therapies for this class of malignancy.
Asunto(s)
Antimetabolitos Antineoplásicos/uso terapéutico , Resistencia a Antineoplásicos , Metotrexato/uso terapéutico , Neoplasias de la Boca/tratamiento farmacológico , Adulto , Anciano , Supervivencia Celular/efectos de los fármacos , Femenino , Humanos , Técnicas In Vitro , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/patología , Estadificación de Neoplasias , Proyectos Piloto , Resultado del TratamientoRESUMEN
Expression of the oncofoetal glycoprotein, carcinoembryonic antigen (CEA), has been observed in a number of malignancies and is also being pursued as a target for anti-cancer therapy. This study explored the status of this biochemical entity in the oral squamous cell carcinoma (SCC) in South India caused by extensive chewing habits. Squamous cell carcinoma in the study belonged to grade I and grade II. Tumour staging of the patients recruited in the study ranged from T2N1M0 to T4N3M0. Of the grade II cases studied, 88% (7 out of 8) showed expression of CEA. The 2 cases of grade I SCC of buccal mucosa also showed positive anti-CEA staining. If the results from this pilot study can be validated with a larger sample size, a role can be attributed to this tumour marker in oral neoplasia, thereby opening up avenues for using CEA as an additional diagnostic marker in oral SCC in this population and as a possible target for anti-cancer therapy.
Asunto(s)
Antígeno Carcinoembrionario/análisis , Carcinoma de Células Escamosas/química , Neoplasias de la Boca/química , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Células Escamosas/etiología , Femenino , Humanos , India , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/etiología , Proyectos Piloto , Tabaco sin Humo/efectos adversosRESUMEN
BACKGROUND: The microsurgical anatomy of the middle cerebral artery (MCA) is of particular interest to the cerebrovascular surgeon. The purpose of this study was to define the microsurgical anatomy of the MCA and its various branches in the Indian population. METHODS: Ten MCAs were studied from five cadaveric brain specimens. The authors studied the outer diameter, length, branches, perforators and site of these on the main trunk (M1), the division of the main trunk, the secondary trunks and their various cortical branches using the operating microscope under 5-20x magnification. RESULTS: The outer diameter of the MCA main trunk ranges from 2.5 to 4 mm with a mean of 3.35 mm. The superolateral branches consisted of polar temporal artery and anterior temporal artery that had a common origin and sometimes the uncal artery or the accessory uncal artery. Perforators or lenticulostriate arteries were seen in the inferomedial surface all along the length of M1. Eight bifurcations and two trifurcations were noted. Cortical branches and their origin are discussed. CONCLUSION: Although the microsurgical anatomy of the MCA in Indian population correlated with the findings in the western literature, some structural and statistical variations were noted.
Asunto(s)
Arteria Cerebral Media/anatomía & histología , Arteria Cerebral Media/cirugía , Procedimientos Neuroquirúrgicos , Humanos , IndiaRESUMEN
The worldwide problem of hepatitis B viral infection has been the focus of a large number of investigations. In the last decade advances have been made in the understanding of the viral function as well as strategies to combat the virus. Lamivudine, Hepsera, and interferon-alpha therapies that are currently used in the clinic are not optimal because of the emergence of resistance in the former modality and/or adverse effects. There are several new nucleosides that are under development for treatment of HBV. With the combination of a number of treatment protocols, it should be possible to bring down the viral load to undetectable levels and minimize the risk of generating mutations that confer resistance to the therapeutic agent.
Asunto(s)
Antivirales/uso terapéutico , Hepatitis B/tratamiento farmacológico , Diseño de Fármacos , Farmacorresistencia Viral/genética , Hepatitis B/virología , Virus de la Hepatitis B/efectos de los fármacos , Virus de la Hepatitis B/genética , Humanos , Lamivudine/uso terapéutico , MutaciónRESUMEN
Intramedullary spinal hemangioblastoma is well known to be accompanied by syringomyelia. However, holocord secondary syringomyelia is uncommon. We present 2 cases of spinal hemangioblastoma, one in the conus medullaris and the other in midthoracic region, accompanied by holocord syrinx. In both the cases the secondary syrinx resolved following successful total tumor excision with good neurological recovery.
Asunto(s)
Hemangioblastoma/patología , Neoplasias de la Médula Espinal/patología , Siringomielia/patología , Adolescente , Adulto , Hemangioblastoma/cirugía , Humanos , Imagen por Resonancia Magnética , Masculino , Neoplasias de la Médula Espinal/cirugía , Siringomielia/cirugíaRESUMEN
The foramen magnum as a site for brain metastasis is extremely rare. We report the case of a 24-year-old male who presented with features of increased intracranial pressure and lower cranial nerve palsies. Imaging revealed a foramen magnum tumor with extension up to the cerebellar vermis superiorly and into the spinal canal inferiorly (craniospinal mass) with mild obstructive hydrocephalus. A malignant melanoma was completely excised. The patient continued to be tumor-free 24 months later.
Asunto(s)
Neoplasias Encefálicas/secundario , Foramen Magno/patología , Melanoma/secundario , Neoplasias Cutáneas/patología , Neoplasias de la Columna Vertebral/secundario , Adulto , Humanos , MasculinoRESUMEN
The emergence of drug-resistant virus in hepatitis B virus (HBV) patients treated with lamivudine is well documented. In this study, we determined the mutations occurring in the tyrosine-methionine-aspartate-aspartate (YMDD) amino acid motif of the HBV DNA polymerase gene, as well as upstream and downstream of this region, in patients with breakthrough virus during lamivudine therapy. Thirty-one Turkish patients (20 patients HBeAg positive, 11 patients HBeAg negative and anti-HBe positive) with chronic HBV infection who completed at least 104 weeks of lamivudine treatment were investigated. All patients received lamivudine, (150 mg/day), for 104 weeks, with or without 4 months of interferon (IFN) combination. HBV-specific sequences were amplified by polymerase chain reaction (PCR) from sera of patients with breakthrough virus, and the PCR products were directly analysed by sequencing. Breakthrough virus was detected in seven of the 31 patients (22.6%) between 9 and 18 months of therapy. Of the seven patients, six were HBeAg positive at baseline, and four had a double mutation consisting of rtM204V and rtL180M, while two had an rtM204I change. In one patient, two base substitutions at rt204 (ATG --> AGT; T to G and G to T) lead to a methionine to serine change (YMDD --> YSDD). This novel DNA pol mutation was detected at month 18 of lamivudine treatment. In addition, this new variant had the rtL180M mutation and a 12 base pair deletion in the pre-S1 region between nucleotides 43-54. The YSDD mutation was still present 6 months after lamivudine discontinuation. In vitro transfection studies also confirmed that the YSDD strain is resistant to lamivudine. In conclusion, the results indicate that, in addition to a Met --> Val and Met --> Ile change in YMDD, a Met --> Ser change at rt204 (YMDD --> YSDD) associated with the rtL180M change can also emerge during lamivudine treatment, which confers lamivudine resistance in vivo and in vitro, leading to virological breakthrough and ALT increases.
Asunto(s)
ADN Polimerasa Dirigida por ADN/genética , Farmacorresistencia Viral/genética , Productos del Gen pol/genética , Virus de la Hepatitis B/genética , Hepatitis B Crónica/tratamiento farmacológico , Hepatitis B Crónica/genética , Lamivudine/uso terapéutico , Mutación , Adulto , Anciano , Antivirales/uso terapéutico , Secuencia de Bases , ADN Viral/análisis , Femenino , Genotipo , Virus de la Hepatitis B/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Farmacogenética , Reacción en Cadena de la Polimerasa , Valores de Referencia , Sensibilidad y EspecificidadRESUMEN
An elderly lady presented with persistent and unexplained excoriated lesions on trunk and limbs of 4 years' duration. No vesicles or bullae ever developed during the course of the disease. Histopathology showed nonspecific dermatitis. The diagnosis of bullous pemphigoid was confirmed by immunofluorescence. The patient responded well to topical steroids and dapsone.
RESUMEN
Erythema nodosum leprosum (ENL) classically presents as tender, erythematous nodules over the face, arms and legs. Severe ENL can become vesicular or bullous and break-down and is termed erythema necroticans (Jopling & McDougall, 1996) and is treated with corticosteroids. The causes of death in a majority of leprosy patients are the same as in the general population, with the exception of renal damage in lepromatous leprosy. There is possible increased mortality from side-effects of antileprosy drugs, steroids, or other drugs used in reactions, from toxaemia in severe reactions, and from asphyxia due to glottic oedema (Jopling & McDougall, 1996). We report here a case of erythema necroticans, the cause of death being septicaemia, secondary to skin ulcers and urinary tract infection, precipitated by corticosteroids.
Asunto(s)
Corticoesteroides/efectos adversos , Eritema Nudoso/patología , Lepra Lepromatosa/patología , Enfermedades Cutáneas Vesiculoampollosas/patología , Corticoesteroides/uso terapéutico , Antiinfecciosos/uso terapéutico , Ciprofloxacina/uso terapéutico , Eritema Nudoso/tratamiento farmacológico , Resultado Fatal , Humanos , Lepra Lepromatosa/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Enfermedades Cutáneas Vesiculoampollosas/tratamiento farmacológicoRESUMEN
BACKGROUND: Exfoliative dermatitis (ED) can result in protein loss due to scaling causing a negative nitrogen balance. Freedberg and Baden (J Invest Dermatol 1962; 38: 277-284) estimated the amount of scale lost in ED by collecting it in an occlusive suit. Subsequently, the nitrogen content was determined by the Kjeldahl method. The exact amount of protein supplementation in ED, dependent on scale loss, is not well established. As occlusion and hyperthermia caused by the suit can inhibit scaling, the objectives of the present study were to design an alternative method to measure the amount of scale lost, to estimate the protein content of the scale, and to propose suitable recommendations for protein supplementation. METHODS: In 40 patients with ED, the total protein content lost through scaling per day (P) was determined by the following equation: P = TxIxYxX/25x10(4) g, where T is the total body surface area in square meters, I is the percentage area involved in scaling, estimated using computer-aided design (CAD graph), Y is the amount of scale lost per unit area (0.0025 m2) in milligrams, and X is the quantity of protein present in 1 g of scale in milligrams estimated by a spectrophotometer. RESULTS: It was observed that patients with ED secondary to drug reactions, eczema, and psoriasis lost 7.2, 9.6, and 22.6 g of scale with a protein content of 4.2, 5.6, and 12.8 g respectively. The difference in the amount of protein lost in ED secondary to drug reactions and eczema was not statistically significant; however, the protein lost in psoriasis was significant (p < 0.01 to p < 0.05). CONCLUSIONS: ED may increase the daily protein loss by approximately 25-30% in psoriasis and 10-15% in other causes. Standard treatment for ED and protein supplementation based on our recommendations can minimize the adverse effects of a negative nitrogen balance.
Asunto(s)
Dermatitis Exfoliativa/metabolismo , Proteínas en la Dieta/metabolismo , Piel/metabolismo , Albúminas/metabolismo , Proteínas Sanguíneas/metabolismo , Dermatitis Exfoliativa/etiología , Dermatitis Exfoliativa/patología , Proteínas en la Dieta/normas , Proteínas en la Dieta/uso terapéutico , Erupciones por Medicamentos/complicaciones , Erupciones por Medicamentos/metabolismo , Eccema/complicaciones , Eccema/metabolismo , Femenino , Globulinas/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Psoriasis/complicaciones , Psoriasis/metabolismo , Piel/patologíaRESUMEN
Telomerase is a unique reverse transcriptase involved in the maintenance of genomic integrity. In an attempt to understand the properties of this enzyme and to study the effect of deoxynucleoside analogues, we have isolated and partially purified telomerase from the blast cells of a patient with acute myelogenous leukemia. During the course of purification of telomerase, three characteristic forms of this enzyme activity were separated. Two processive forms and one less processive form were noted. All forms of the enzyme activities could be abolished by RNase A and proteinase K treatments, implying that they are ribonucleoproteins. The major form of telomerase was characterized with respect to divalent ion requirements, effect of salt and nonionic detergents. The Km of deoxynucleoside triphosphates was determined with a modified telomerase repeat array protocol assay. Studies with deoxynucleoside analogues indicated that 3'-azido-3'deoxythymidine triphosphate is much more inhibitory than 2',3'-dideoxy 2',3'didehydrothymidine triphosphate, and the cytidine analogue ddCTP was not inhibitory. ddGTP was the most potent inhibitor among all dideoxynucleosides studied.
Asunto(s)
Desoxirribonucleótidos/farmacología , Leucemia Mieloide Aguda/enzimología , Telomerasa/metabolismo , Cromatografía por Intercambio Iónico , Relación Dosis-Respuesta a Droga , Electroforesis en Gel de Poliacrilamida , Endopeptidasa K/farmacología , Ensayo de Inmunoadsorción Enzimática , Humanos , Reacción en Cadena de la Polimerasa , Cloruro de Potasio/farmacología , Ribonucleasa Pancreática/farmacología , Telomerasa/efectos de los fármacos , Telomerasa/aislamiento & purificación , Células Tumorales Cultivadas/enzimologíaRESUMEN
The acyclic cytosine nucleoside analog cytallene [1-(4'-hydroxy-1',2'-butadienyl)cytosine], which has both (+)- and (-)-enantiomers, was evaluated for its anti-hepatitis B virus (HBV) activity in 2.2.15 cells and was found to have potent activity against HBV DNA synthesis. The R-(-)-enantiomer was found to be the more active of the cytallene enantiomers, with a 50% inhibition concentration against HBV synthesis (HBIC50) of 0.08 microM. Its antiviral activity could be reversed by deoxycytidine (dC) and less efficiently by cytidine. Upon removal of the R-(-)-enantiomer from culture medium, the synthesis of HBV DNA could reinitiate, which suggested that the antiviral action is reversible. The R-(-)-enantiomer was also found to be more cytotoxic than the S-(+)-enantiomer. The degree of cytotoxicity varied among the cell lines, with a 50% inhibition of cell growth at greater than 10 microM. The R-(-)-enantiomer had no effect on HBV RNA synthesis and mitochondrial DNA synthesis at a concentration of 10 times or more than the HBIC50. The two enantiomers cannot be deaminated by dC deaminase, and they can be phosphorylated by cytoplasmic dC kinase. The R-(-)-enantiomer of cytallene is the first acyclic cytosine analog with potent inhibitory activity against HBV similar to those of other L-(-)-ddC analogs.
Asunto(s)
Antivirales/farmacología , Citosina/análogos & derivados , Virus de la Hepatitis B/efectos de los fármacos , Virus de la Hepatitis B/genética , Replicación Viral/efectos de los fármacos , Antivirales/química , Antivirales/metabolismo , Citosina/química , Citosina/metabolismo , Citosina/farmacología , ADN Mitocondrial/efectos de los fármacos , ADN Viral/análisis , Relación Dosis-Respuesta a Droga , Antígenos de Superficie de la Hepatitis B/efectos de los fármacos , Virus de la Hepatitis B/fisiología , Fosforilación , ARN Viral/efectos de los fármacosRESUMEN
This paper is a detailed description of an improvised operative technique used by us, for ventral screw fixation in a case of type II odontoid fracture.
RESUMEN
Since 2'-fluoro-5-methyl-beta-L-arabinofuranosyluracil (L-FMAU) has been shown to be a potent anti-HBV agent in vitro, it was of interest to study the structure-activity relationships of related nucleosides. Thus, a series of 1-(2-deoxy-2-fluoro-beta-L-arabinofuranosyl)pyrimidine nucleosides have been synthesized and evaluated for antiviral activity against HBV in 2.2.15 cells. For this study, L-ribose was initially used as the starting material. Due to the commercial cost of L-ribose, we have developed an efficient procedure for the preparation of L-ribose derivative 6. Starting from L-xylose, 6 was obtained in an excellent total yield (70%) through the pyridinium dichromate oxidation of the 3-OH group followed by stereoselective reduction with NaBH4. It was further converted to the 1,3,5-tri-O-benzoyl-2-deoxy-2-fluoro-alpha-L-arabinofuranose (10), which was then condensed with various 5-substituted pyrimidine bases to give the nucleosides. Among the compounds synthesized, the lead compound, L-FMAU (13), exhibited the most potent anti-HBV activity (EC50 0.1 microM). None of the other uracil derivatives showed significant anti-HBV activity up to 10 microM. Among the cytosine analogues, the cytosine (27) and 5-iodocytosine (35) derivatives showed moderately potent anti-HBV activity (EC50 1.4 and 5 microM, respectively). The cytotoxicity of these nucleoside analogues has also been assessed in 2.2.15 cells as well as CEM cells. None of these compounds displayed any toxicity up to 200 microM in 2.2.15 cells. Thus, compound 13 (L-FMAU), 27, and 35 showed a selectivity of over 2000, 140, and 40, respectively.
Asunto(s)
Antivirales/síntesis química , Arabinonucleósidos/síntesis química , Virus de la Hepatitis B/efectos de los fármacos , Antivirales/farmacología , Arabinofuranosil Uracilo/análogos & derivados , Arabinofuranosil Uracilo/química , Arabinofuranosil Uracilo/farmacología , Arabinonucleósidos/farmacología , Línea Celular , Estructura Molecular , Relación Estructura-ActividadRESUMEN
Short DNA duplexes with cholesterol linked at the 3'-terminus of each strand have unique, selective cytotoxic properties. The structural requirements for biological activity were explored through chemical synthesis of analogs and testing in cultured hepatoma cells. Effects of modifications to the sequence, backbone, 3'-sterol, 3'-linker, and 5'-terminus were evaluated. Self-complementary 3'-modified oligodeoxynucleotide (ODN) 10-mers were prepared from solid supports bearing the modification and linker of interest. Any changes to the normal phosphodiester backbone were poorly tolerated. The presence of cholesterol or a closely related sterol was an absolute requirement for activity. The length and position of attachment of the linker to cholesterol was important, with longer linkers showing reduced activity. Large, lipophilic groups at the 5'-terminus gave reduced cytotoxicity and poor solubility properties. The short length and unique structure of these ODNs allowed efficient automated synthesis on a 400 mumol scale and simplified purification.