RESUMEN
BACKGROUND: Fifty tumor specimens from primarily untreated patients were analyzed to elucidate the involvement of the tumor suppressor gene PTEN/MMAC1 in the development of oral squamous cell cancer. METHODS: Eight microsatellite markers, spanning 10 cM of genomic DNA located centromeric, telomeric or intragenic of PTEN/MMAC1 were used for loss of heterozygosity (LOH) and breakpoint analysis. The microsatellite panel within or in close proximity (1 cM) to the 10q23.3 locus showed a LOH rate of 12%. Complete sequence analysis of the genes coding region was performed in all 10 cases that exhibited LOH in one of the eight microsatellite markers within or around the PTEN/MMAC1 gene. Comparative multiplex PCR reactions served to screen for homozygous deletions. RESULTS: There was no association between allelic loss of the gene, overall patient survival and recurrence-free survival. Sequencing did not reveal any mutation in the coding region of PTEN/MMAC1. Differential PCR analysis failed to detect any homozygous deletion. CONCLUSIONS: We conclude that PTEN/MMAC1 gene alterations do not play a key role in tumorigenesis of oral squamous cell cancers.
Asunto(s)
Carcinoma de Células Escamosas/genética , Genes Supresores de Tumor/fisiología , Mutación de Línea Germinal/genética , Neoplasias de la Boca/genética , Monoéster Fosfórico Hidrolasas/genética , Proteínas Supresoras de Tumor/genética , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Centrómero/genética , Cromosomas Humanos Par 10/genética , Supervivencia sin Enfermedad , Femenino , Eliminación de Gen , Marcadores Genéticos/genética , Homocigoto , Humanos , Modelos Lineales , Pérdida de Heterocigocidad/genética , Masculino , Repeticiones de Microsatélite/genética , Persona de Mediana Edad , Recurrencia Local de Neoplasia/genética , Fosfohidrolasa PTEN , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , Estadística como Asunto , Estadísticas no Paramétricas , Tasa de Supervivencia , Telómero/genéticaRESUMEN
Ectopic thyroid tissue in the submandibular space with the thyroid gland in its normal location is an extremely rare phenomenon. We present a case of a 75-year-old woman who had painless swelling in the left submandibular space and was referred to our hospital with the suspicion of having a malignant tumor originating from the submandibular gland. Histologic examination showed normal follicular thyroid tissue without any sign of malignancy. In general there are 3 explanations for the presence of ectopic thyroid tissue found in the submandibular region: (1) displacement during the course of embryonal development, (2) spread of tissue during surgery on a normally located thyroid gland, and (3) metastasis of a highly differentiated papillary thyroid carcinoma. We reviewed the literature with respect to the embryological background and the clinical management of such cases.
Asunto(s)
Coristoma/patología , Enfermedades de la Glándula Submandibular/patología , Glándula Tiroides/fisiología , Anciano , Coristoma/cirugía , Femenino , Humanos , Cintigrafía , Radiofármacos , Pertecnetato de Sodio Tc 99m , Enfermedades de la Glándula Submandibular/cirugía , Glándula Tiroides/diagnóstico por imagen , Tomografía Computarizada por Rayos XRESUMEN
A cell line was established from the tunica vaginalis of meadow voles, Microtus pennsylvanicus, which could be persistently infected with the spotted fever group rickettsiae, Rickettsia rickettsii, R. rhipicephali, and R. slovaca. As determined by light and electron microscopy, all cells in the cultures became infected and remained so even after 20 serial passages over a period of months. The rickettsiae-infected vole cell line is an excellent experimental model to study the noncytolytic host-cell interactions required for persistence of spotted fever group rickettsiae in nature.
Asunto(s)
Rickettsia/patogenicidad , Animales , Arvicolinae , Células Cultivadas , Microscopía , Microscopía Electrónica , Rickettsia rickettsii/patogenicidadRESUMEN
Rocky Mountain (Sylvilagus nuttallii) and eastern (S. floridanus) cottontails were examined for their susceptibility to virulent and avirulent strains of the spotted fever agent, Rickettsia rickettsii. Both species of rabbits responded to inoculation of yolk sac suspensions containing 500 egg LD50 of either virulent or avirulent rickettsiae, with rickettsemias detectable as early as 3 days after inoculation and lasting up to 7 days. When fed upon by infected ticks, only one of three Rocky Mountain and one of four eastern cottontails developed rickettsemias detectable in embryonated hens' eggs. Rickettsial concentrations in the peripheral blood fo Rocky Mountain cottontails, infected either by syringe or by bites of one or more Dermacentor andersoni ticks harboring virulent R. rickettsii, were sufficient to infect simultaneously feeding normal larvae of this tick species. However, infection rates wre low and did not exceed 11.7%. In a single experiment, the bites of D. variabilis, infected with an avirulent strain of R. rickettsii, did not produce rickettsemias sufficient to infect normal D. variabilis larvae. These laboratory findings suggest that cottontail rabbits, although susceptible to R. rickettsii, do not serve as efficient reservoirs for infecting ticks.
Asunto(s)
Reservorios de Enfermedades , Conejos/microbiología , Fiebre Maculosa de las Montañas Rocosas/transmisión , Animales , Dermacentor/microbiología , Estados UnidosRESUMEN
In a study to determine susceptibility to Borrelia hermsii of various rodents commonly found in or near places where human cases of relapsing fever occurred, chipmunks (Eutamias amoenus), pine squirrels (Tamiasciurus hudsonicus richardsoni), flying squirrels (Glaucomys sabrinus), Columbian ground squirrels (Spermophilus columbianus columbianus), golden-mantled ground squirrels (S. lateralis tescorum), wood rats (Neotoma cinerea cinerea), white-footed deer mice (Peromyscus maniculatus), and meadow voles (Microtus pennsylvanicus) were exposed to spirochetes either by bites of infected Ornithodoros hermsi or by injection of infectious tick suspensions. Daily microscopic examination of blood samples revealed that pine squirrels, chipmunks, and meadow voles responded with spirochetemias of various degrees and length. Pine squirrels were most susceptible and experienced long-lasting and severe spirochetemias accompanied by typical signs of illness. Flying squirrels, Columbian ground squirrels, golden-mantled ground squirrels, wood rats, and white-footed deer mice did not develop demonstrable spirochetal infection.
