A prospective, randomized, double-blind trial of intranasal dexmedetomidine and oral chloral hydrate for sedated auditory brainstem response (ABR) testing.

BACKGROUND: Dexmedetomidine is increasingly used by various routes for pediatric sedation. However, there are few randomized controlled trials comparing the efficacy of dexmedetomidine to other commonly used sedatives. AIM: To compare the efficacy of sedation with intranasal dexmedetomidine to oral chloral hydrate for auditory brainstem response (ABR) testing. METHODS: In this double-blind, double-dummy study, children undergoing ABR testing were randomized to receive intranasal dexmedetomidine 3 mcg · kg(-1) plus oral placebo (Group IN DEX) or oral chloral hydrate 50 mg · kg(-1) plus intranasal saline placebo (Group CH). We recorded demographic data, times from sedative administration to start and completion of testing, quality of sedation, occurrence of predefined adverse events, discharge times, and return to baseline activity on the day of testing. RESULTS: Testing completion rates with a single dose of medication were higher in the IN DEX group (89% vs 66% for CH, odds ratio with 95% confidence intervals 4.04 [1.3-12.6], P = 0.018). The median [95% CI)] time to successful testing start was shorter (25 [20-29] min vs 30 [20-49] min for IN DEX and CH, respectively, log rank test P = 0.02) and the proportion of children whose parents reported a return to baseline activity on the day of testing was greater for the IN DEX than the CH group (89% vs 64%, OR [95% CI] 4.71 [1.34-16.6], P = 0.02). There were no major adverse events in either group and no significant differences in the incidence of minor events. CONCLUSION: Intranasal dexmedetomidine is an effective alternative to oral chloral hydrate sedation for ABR testing, with the advantages of a higher incidence of testing completion with a single dose, shorter time to desired sedation level, and with significantly more patients reported to return to baseline activity on the same day.

[Geographic variation of the fox Lycalopex culpaeus (Mammalia, Canidae) in Chile: taxonomic implications]. / Variación geográfica del zorro Lycalopex culpaeus (Mammalia, Canidae) en Chile: implicaciones taxonómicas.

We studied the geographic variation of skulls of Lycalopex culpaeus using qualitative and quantative analyses. The sampling area covered Chile, from its northern portion, to Tierra del Fuego and the neighbouring Hoste Island, as well as part of Argentina. Five subespecies are currently recognized from this large area. We found two morphotypes that are segregated geographically. Both groups mostly differ by morphometric attributes, followed by qualitative features. Specimens from northern Chile (Tarapacá and Antofagasta) have small skulls, short rostrum, a liriform sagital zone, and lack the interparietal crest. The second group is formed by specimens from north-western and central Argentina, central-south Chile, Patagonia, and the austral islands of Tierra del Fuego and Hoste. This group presents a strong sagital crest, large rostrum, and a large skull. Our results agree with observed patterns of mitochondrial DNA variation. We propose to retain the name L. c. andinus for the populations of northern Chile and to synonymize L. c. magellanicus, L. c. lycoides, and L. c. smithersi under L. c. culpaeus.

Histological changes of the peripheral zone in small and large prostates and possible clinical implications.

INTRODUCTION: It is well documented in literature that most prostate carcinomas (PCa) arise in the peripheral zone (PZ). Additionally, an inverse relationship between prostate size and the incidence of PCa has been demonstrated in recent studies. However, little is known about gland distribution in the peripheral zone of larger prostates compared to smaller prostates. In this study, we examined the histo-anatomical gland distribution within the peripheral zone in small and large prostates and discuss possible clinical implications. METHODS: A semi-quantitative analysis of gland density and capsule thickness was performed using light microscopy on 10 large (≥80 g) prostate specimens and 10 small (<30 g) prostate specimens from patients who underwent radical prostatectomy at Texas Tech University Health Sciences Center between the years 2010 and 2016. Samples from radical prostatectomies were used to ensure a whole, preserved prostate with an intact surgical capsule. Gland counts were performed on five random fields under 100 × magnification, while capsule thickness was measured on three random fields per case; thus, a total 50 fields and 30 fields were analyzed for each of the two groups for gland counts and capsule thickness measurements, respectively. Microscopy was standardized to the posterior aspect of the prostate, between 4 o'clock and 6 o'clock along the equatorial region between the apex and base. RESULTS: Large prostates possessed a significantly lower mean gland count per field compared to small prostates (10.34±4.15, n=50 vs 18.00±5.41, n=50; t=8.16, df=49, P<0.001). Additionally, large prostates showed a significantly higher average capsule thickness in millimeters compared to small prostates (1.80 mm, ±1.12 mm, n=30 vs 0.90 mm, ±0.56, n=30; t=8.16, df=49, P<0.001). CONCLUSION: The results demonstrate that prostate hypertrophy leads to both decreased gland density in the peripheral zone and increased capsule thickness, suggesting that growth-induced expansion of the prostate against its capsule leads to compression-induced atrophy and fibrosis of glandular tissue within the peripheral zone (PZ). A decrease in gland density within the PZ may have clinical implications shedding light, for instance, on the reduction in PCa incidence in patients with large prostates as compared to smaller prostates, a phenomenon well documented in the literature.

Variación geográfica del zorro Lycalopex culpaeus (Mammalia, Canidae) en Chile: implicaciones taxonómicas

Geographic variation of the fox Lycalopex culpaeus (Mammalia, Canidae) in Chile: taxonomic implications. We studied the geographic variation of skulls of Lycalopex culpaeus using qualitative and quantative analyses. The sampling area covered Chile, from its northern portion, to Tierra del Fuego and the neighbouring Hoste island, as well as part of Argentina. Five subespecies are currently recognized from this large area. We found two morphotypes that are segregated geographically. Both groups mostly differ by morphometric attributes, followed by qualitative features. Specimens from northern Chile (Tarapacá and Antofagasta) have small skulls, short rostrum, a liriform sagital zone, and lack the interparietal crest. The second group is formed by specimens from north-western and central Argentina, central-south Chile, Patagonia, and the austral islands of Tierra del Fuego and Hoste. This group presents a strong sagital crest, large rostrum, and a large skull. Our results agree with observed patterns of mitochondrial DNA variation. We propose to retain the name L. c. andinus for the populations of northern Chile and to synonymize L. c. magellanicus, L. c. lycoides, and L. c. smithersi under L. c. culpaeus. Rev. Biol. Trop. 57 (1-2): 421-432. Epub 2009 June 30.

Mediante análisis cualitativos y cuantitativos, se estudió la variación geográfica del cráneo de Lycalopex culpaeus en Chile (desde Tarapacá a la islas australes), y de algunas poblaciones argentinas. En dicha distribución se reconocen cinco de las seis subespecies del culpeo. Los resultados muestran dos grupos morfológicos geográficamente segregados; los mismos se diferencian principalmente por atributos morfométricos, y secundariamente por caracteres cualitativos. individuos del norte chileno (Tarapacá y Antofagasta) presentan cráneos pequeños, poco desarrollados, hocico levemente corto, ausencia de cresta interparietal y una tenue zona sagital "liriforme". Por otra parte, los individuos del noroeste y centro argentino, centro sur chileno, Patagonia e islas australes (islas de Tierra del Fuego y Hoste) (grupo B), no muestran diferencias significativas en su morfometría dento-craneal. En el grupo B destacó una fuerte cresta interparietal y zona sagital, hocicos prolongados y cráneos de mayor tamaño que los del norte chileno. Nuestros resultados coinciden con estudios de patrones de variación en el ADN mitocondrial de cánidos de Chile. Por lo tanto, se propone mantener el nombre L. c. andinus para las poblaciones del norte de Chile y sinonimizar los taxones L. c. magellanicus, L. c. lycoides y L. c. smithersi bajo la forma L. c. culpaeus.