Comparing genetic diversity and demographic history in co-distributed wild South American camelids.

Vicuñas and guanacos are two species of wild South American camelids that are key ruminants in the ecosystems where they occur. Although closely related, these species feature differing ecologies and life history characters, which are expected to influence both their genetic diversity and population differentiation at different spatial scales. Here, using mitochondrial and microsatellite genetic markers, we show that vicuña display lower genetic diversity within populations than guanaco but exhibit more structure across their Peruvian range, which may reflect a combination of natural genetic differentiation linked to geographic isolation and recent anthropogenic population declines. Coalescent-based demographic analyses indicate that both species have passed through a strong bottleneck, reducing their effective population sizes from over 20,000 to less than 1000 individuals. For vicuña, this bottleneck is inferred to have taken place ~3300 years ago, but to have occurred more recently for guanaco at ~2000 years ago. These inferred dates are considerably later than the onset of domestication (when the alpaca was domesticated from the vicuña while the llama was domesticated from the guanaco), coinciding instead with a major human population expansion following the mid-Holocene cold period. As importantly, they imply earlier declines than the well-documented Spanish conquest, where major mass mortality events were recorded for Andean human and camelid populations. We argue that underlying species' differences and recent demographic perturbations have influenced genetic diversity in modern vicuña and guanaco populations, and these processes should be carefully evaluated in the development and implementation of management strategies for these important genetic resources.

Dysphagia Incidence after Outpatient Anterior Cervical Surgery Using Instrumentation versus No Instrumentation / Incidencia de la disfagia tras la cirugía cervical anterior ambulatoria con instrumentación y sin instrumentación

ABSTRACT Objective: Dysphagia is a relatively common occurrence in the postoperative period following anterior cervical surgery, with some indicating rates as high as 79%. In most cases, it remains only a transient phenomenon. The cause has been debated, with most speculating injury to nerves in the swallowing mechanism. The objective of this study was to determine if the presence of instrumentation during anterior cervical surgery in the outpatient setting would affect the incidence, duration and severity of dysphagia. Methods: We did a retrospective review of the medical records of 50 consecutive patients who had undergone single-level instrumented anterior cervical discectomy and fusion. Then we compared that group with our control group of 50 patients who had had simple single-level anterior cervical discectomy without instrumentation or fusion. The patients were evaluated for the presence of dysphagia as well as neck disability index outcome scores. Results: There was no significant difference between the groups in postoperative neck disability index outcomes at the two-year follow-up (p = 0.182). Dysphagia occurred only in the instrumented group, with an incidence of 12% (six patients): their symptoms lasted on average three weeks, and all six patients experienced only mild severity on the Bazaz-Yoo scale. There was statistically significant difference between the two groups (p = 0.012). Conclusion: There was a greater trend towards postoperative dysphagia in cases with instrumentation (12% of the patients). Dysphagia was transient with mild severity in patients who received instrumentation compared with those who underwent discectomy alone.

RESUMEN Objetivo: La disfagia es una ocurrencia relativamente común en el período postoperatorio después de la cirugía cervical anterior, con algunas tasas indicadoras tan altas como 79%. En la mayoría de los casos, sigue siendo sólo un fenómeno transitorio. Su causa ha sido discutida, atribuyéndose principalmente a una lesión en los nervios del mecanismo de deglución. El objetivo de este estudio fue determinar si la presencia de la instrumentación durante la cirugía cervical anterior en el contexto ambulatorio afectaría la incidencia, duración y severidad de la disfagia. Métodos: Realizamos una revisión retrospectiva de las historias clínicas de 50 pacientes consecutivos que habían tenido discectomía y fusión cervical anterior con instrumentación a un solo nivel. Entonces comparamos ese grupo con nuestro grupo de control de 50 pacientes a quienes se les había practicado una discectomía cervical anterior a un solo nivel simple sin instrumentación o fusión. Los pacientes fueron evaluados con respecto a la presencia de disfagia, así como en relación con las puntuaciones del resultado del índice de la discapacidad cervical. Resultados: No hubo diferencias significativas entre los grupos en cuanto a los resultados del índice de discapacidad cervical postoperatorio en el seguimiento de dos años (p = 0.182). La disfagia se produjo sólo en los grupos con instrumentación, con una incidencia de 12% (seis pacientes): sus síntomas duraron un promedio de tres semanas, y los seis pacientes experimentaron toda una severidad leve en la escala de Bazaz-Yoo. Hubo una diferencia estadísticamente significativa entre los dos grupos (p = 0.012). Conclusión: Hubo una mayor tendencia a la disfagia postoperatoria en los casos con instrumentación (12% de los pacientes). La disfagia fue transitoria con severidad leve en los pacientes que recibieron instrumentación, comparada con la de los que experimentaron discectomía solamente.

Comparación de las características mecánicas estáticas del fémur aislado de perro, con y sin la colocación de una placa de ortopedia fabricada en polipropileno / Compare the mechanical statistical characteristics of dog femur isolet, with or without placing to an orthopedic píate made of polypropylene

Los objetivos generales fueron: evaluar resistencia a la compresión del fémur derecho aislado y del fémur izquierdo osteotomizado transversalmente fijado con una placa ortopédica fabricada en polipropileno, y comparar las características mecánicas estáticas entre ambos. Este trabajo se realizó mediante la confección de un modelo experimental de carga constituido por un fémur de mamífero (perro) en condiciones aisladas. Se utilizaron los huesos fémur de 13 perros mestizos, adultos jóvenes, de talla mediana a grande. Para los pruebas se utilizó una máquina servohidráulica para ensayos estáticos y dinámicos Amsler Wolpert. Se utilizó para el tratamiento de los datos, el test estadístico de diferencias de medias para muestras pareadas dependientes. Como resultado del análisis de las curvas se obtuvo que: el fémur derecho soportó antes de la falla, entre 4,02 a 8,47 KN de carga (= 6,66 KN) con una deformación de 2,02 a 5,09 mm (= 3,66 mm). En tanto el conjunto fémur izquierdo + placa ortopédica soportó antes de la falla, entre 3,05 a 5,61 KN de carga (= 4,49 KN) con una deformación de 2 a 4.5 mm (= 3 mm). Como conclusión, es posible afirmar que hay diferencias en la resistencia a la carga compresiva entre el fémur derecho y su contralateral izquierdo + placa ortopédica.

The general aims were: to evaluate the resistance to compression of the right femur isolated and that of the left femur transversally osteotomized fixed to an orthopedic plate made of polypropylene and to compare the mechanical statistical characteristics between both. This work was carried out by performing an experimental charge pattern made of a mammal femur (dog) under isolated conditions. Femur bones of 13 hybrid young adult dogs of medium to large size were used. A servohydric engine was used for the Amsler Wolpert static and dynamic essays. The mean difference statistical test for depending paired samples was used for the evaluation of data. As a result of the curves analysis it was obtained that: before failure the right femur underwent a charge of 4.02 to 8.47 KN (= 6.66 KN) with a deformation of 2.02 to 5.09 mm (= 3.66mm) while the charge that the left femur + orthopedic plate underwent before de failure was of 3.05 to 5.61 KN ( = 4.49KN) with a deformation of 2 to 4.5 mm ( = 3mm). As a conclusion it might be stated that there are differences in the resistance to the compressive charge between right femur and its left contra lateral + the orthopedic plate.

Mitochondrial phylogeography and demographic history of the vicuña: implications for conservation.

The vicuña (Vicugna vicugna; Miller, 1924) is a conservation success story, having recovered from near extinction in the 1960s to current population levels estimated at 275,000. However, lack of information about its demographic history and genetic diversity has limited both our understanding of its recovery and the development of science-based conservation measures. To examine the evolution and recent demographic history of the vicuña across its current range and to assess its genetic variation and population structure, we sequenced mitochondrial DNA from the control region (CR) for 261 individuals from 29 populations across Peru, Chile and Argentina. Our results suggest that populations currently designated as Vicugna vicugna vicugna and Vicugna vicugna mensalis comprise separate mitochondrial lineages. The current population distribution appears to be the result of a recent demographic expansion associated with the last major glacial event of the Pleistocene in the northern (18 to 22 degrees S) dry Andes 14-12,000 years ago and the establishment of an extremely arid belt known as the 'Dry Diagonal' to 29 degrees S. Within the Dry Diagonal, small populations of V. v. vicugna appear to have survived showing the genetic signature of demographic isolation, whereas to the north V. v. mensalis populations underwent a rapid demographic expansion before recent anthropogenic impacts.

Prevalence of superantigen-secreting bacteria in patients with Kawasaki disease.

OBJECTIVES: To assess the prevalence of superantigen secreting bacteria in children with acute Kawasaki disease (KD) relative to control patients. STUDY DESIGN: Bacterial cultures were obtained in a blinded fashion from the throat, rectum, and groin of 45 patients with untreated acute KD and 37 febrile control patients from 6 centers in the United States. Cultures were processed for the presence of superantigen-producing bacteria at a central laboratory. RESULTS: Staphylococci or streptococci that produced superantigens (TSST-1, SEB, SEC, SPEB, SPEC) were isolated from 25 of 45 patients with KD (56%) as compared with 13 of 37 (35%) control patients (P =.078). Because SEB- and SEC-producing Staphylococcus aureus have not been associated with KD and because they do not induce a Vbeta2+ T-lymphocyte response, we analyzed the difference between groups relative to superantigens TSST-1 or SPEB/SPEC production. TSST-1 secreting S aureus or SPEB/SPEC producing group A streptococci were isolated from 20 of 45 (44%) patients with KD compared with 7 of 37 (19%) control patients (P =.019). CONCLUSIONS: The overall isolation rates of superantigen (TSST-1, SPEB, SPEC, SEB, SEC) producing bacteria between patients with KD and febrile control patients were not statistically significant. However, future studies should further examine the potential role of Vbeta2-stimulatory superantigens (TSST-1 and SPEB/SPEC) in KD.

Genetic analysis reveals the wild ancestors of the llama and the alpaca.

The origins of South America's domestic alpaca and llama remain controversial due to hybridization, near extirpation during the Spanish conquest and difficulties in archaeological interpretation. Traditionally, the ancestry of both forms is attributed to the guanaco, while the vicuña is assumed never to have been domesticated. Recent research has, however, linked the alpaca to the vicuña, dating domestication to 6000-7000 years before present in the Peruvian Andes. Here, we examine in detail the genetic relationships between the South American camelids in order to determine the origins of the domestic forms, using mitochondrial (mt) and microsatellite DNA. MtDNA analysis places 80% of llama and alpaca sequences in the guanaco lineage, with those possessing vicuña mtDNA being nearly all alpaca or alpaca-vicuña hybrids. We also examined four microsatellites in wild known-provenance vicuña and guanaco, including two loci with non-overlapping allele size ranges in the wild species. In contrast to the mtDNA, these markers show high genetic similarity between alpaca and vicuña, and between llama and guanaco, although bidirectional hybridization is also revealed. Finally, combined marker analysis on a subset of samples confirms the microsatellite interpretation and suggests that the alpaca is descended from the vicuña, and should be reclassified as Vicugna pacos. This result has major implications for the future management of wild and domestic camelids in South America.

Persistence of anti-leptospiral IgM, IgG and agglutinating antibodies in patients presenting with acute febrile illness in Barbados 1979-1989.

The persistence of anti-leptospiral IgM and IgG antibodies and agglutinating antibodies was studied in serologically confirmed cases of severe leptospirosis during the acute illness and over periods of several years after recovery. The antibody response in non-leptospirosis patients presenting to hospital with similar symptoms over the same period of time was used to estimate the background antibody level to leptospirosis in the community. All patients enrolled in the study had blood samples collected twice in the acute stage of illness, once during convalescence and then annually from the time of initial hospitalisation until the end of the study period. Six hundred and thirty-eight patients presented to hospital with acute febrile illness, of whom 321 were diagnosed with leptospirosis. Patients who had severe leptospirosis commonly remained seropositive, with IgM, IgG and agglutinating antibodies detectable for several years after infection. A significant proportion of cases had high titres of agglutinating antibody detectable by the microscopic agglutination test (> or = 800). There were marked differences in the magnitude and duration of persistence of agglutinating antibodies directed against different serogroups. More than 20% of cases with evidence of infection with serogroup Autumnalis retained titres of >800, 4 years after the acute illness. In one case a titre of 800 was detected 11 years after infection. Persistence of agglutinating antibody titres can create problems in interpretation of serological results and make it impossible to estimate the time of infection, given a specific titre. This study demonstrates that in endemic areas where seroprevalence is high, use of a single elevated titre is not reliable to define a current infection.

Predicting the community prevalence of schistosomiasis mansoni from the prevalence among 7- to 14-year-olds.

The World Health Organization suggested that the prevalence of Schistosoma mansoni among 7- to 14-year-olds be used to guide treatment strategies in endemic areas. This study explores how well the prevalence in that age group predicted the overall prevalence in the community in data from stool examinations (Kato-Katz method) from 180,000 people in 3 municipalities in Brazil in 1984 and 1985. The median prevalence was higher in 1984, before community treatment was introduced. There was a strong relationship between the prevalence among 7- to 14-year-olds and the overall prevalence in the community. We present sensitivities and positive predictive values for the use of prevalence in the indicator group to select communities for mass treatment as recommended by WHO. For a range of assumptions sensitivity and positive predictive value were never both above 80 %. We suggest that the estimates of validity presented in this paper inform future evaluations of strategies for S. mansoni control.

A randomized, double-blind, placebo-controlled trial of prophylactic recombinant human granulocyte-macrophage colony-stimulating factor to reduce nosocomial infections in very low birth weight neonates.

OBJECTIVE: We carried out a randomized placebo-controlled trial in very low birth weight neonates (VLBWNs), comparing the incidence of nosocomial infections after the prophylactic use of recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF) versus placebo in VLBWNs. STUDY DESIGN: VLBWNs (n = 264), weighing 501 to 1000 g, /=4000/mm,3 peripheral blood progenitor studies, and 24-hour polymorphonuclear leukocyte C3bi receptor expression were compared between the 2 treatment groups. RESULTS: No (grade III/IV) toxicity or adverse events were associated with rhu GM-CSF. The absolute neutrophil count and absolute eosinophil count were significantly elevated in the rhu GM-CSF group on days 7 (P =.001), 14 (P =.001), and 21 (P =.007) and on days 7 and 28 (P =.012 and P =.001, respectively). However, there was no difference in the incidence of confirmed nosocomial infections between the 2 treatment groups in this trial (40% vs 39%, rhu GM-CSF vs placebo; P = NS). CONCLUSION: In a large randomized placebo-controlled trial, prophylactic administration of rhu GM-CSF in VLBWNs does not appear to decrease the incidence of nosocomial infections.

Atopic dermatitis and food hypersensitivity reactions.

OBJECTIVE: To determine the role of food hypersensitivity in atopic dermatitis and to determine whether patients with atopic dermatitis who had food hypersensitivity could be identified by screening prick skin tests using a limited number of food allergens. STUDY DESIGN: Patients with atopic dermatitis attending the Arkansas Children's Hospital Pediatric Allergy Clinic underwent allergy prick skin testing to a battery of food antigens. Patients with positive prick skin tests underwent double-blind, placebo-controlled food challenges. RESULTS: One-hundred sixty-five patients were enrolled and completed the study. Patients ranged in age from 4 months to 21.9 years (mean 48.9 months). Ninety-eight (60%) patients had at least one positive prick skin test. A total of 266 double-blind, placebo-controlled food challenges were performed. Sixty-four patients (38.7% of total) were interpreted as having a positive challenge. Seven foods (milk, egg, peanut, soy, wheat, cod/catfish, cashew) accounted for 89% of the positive challenges. By use of screening prick skin tests for these seven foods we could identify 99% of the food allergic patients correctly. CONCLUSIONS: This study confirms that most children with atopic dermatitis have food allergy that can be diagnosed by a prick skin test for the seven foods.

Serum sickness-like reactions to cefaclor: role of hepatic metabolism and individual susceptibility.

In an effort to explain the increased incidence of serum sickness-like reactions (SSLR) in patients receiving cefaclor, we used an in vitro murine microsomal system as a surrogate for in vivo hepatic drug biotransformation. Lymphocytes from three groups of subjects were exposed to a nonselective mixture of cefaclor metabolites. After an 18-hour incubation of lymphocytes with these metabolites, cells were examined for viability by trypan blue exclusion. The subject groups consisted of patients with a previous history of SSLR after cefaclor therapy (n = 19), patients who experienced adverse reactions to cefaclor suggestive of immediate hypersensitivity (n = 11), and control subjects who had previously tolerated at least two courses of cefaclor therapy without adverse effect (n = 9). Additionally, immediate family members of six subjects with cefaclor-associated SSLR were studied. Lymphocyte killing was 100% greater than baseline (i.e., a non-drug-containing control) in subjects with SSLR compared with those with immediate hypersensitivity reactions (4% cell death above baseline; p < 0.001) and nonaffected control subjects (6% cell death above baseline; p < 0.001). Family studies were consistent with a pattern of maternal inheritance; five of six mothers who had not received cefaclor had a positive (i.e., > or = 35% cell death above baseline) in vitro cytotoxic response. Other studies confirmed the requirement for biotransformation of the parent drug to elicit cell death, demonstrated specificity of the reaction to cefaclor, illustrated a lack of cross-reactivity to cephalexin in subjects with SSLR to cefaclor, and verified the reproducibility of the reaction over time in an affected subject. Our findings indicate that cefaclor associated SSLR may be a unique adverse drug reaction that requires biotransformation of the parent drug and may result from inherited defects in the metabolism of reactive intermediates. Furthermore, this condition can be retrospectively confirmed with an in vitro lymphocyte-based cytotoxicity assay.

Serum sickness-like reactions associated with cefprozil therapy.

Four patients had serum sickness-like reactions during treatment with cefprozil, a new cephalosporin. Two patients had had previous mild reactions associated with cephalosporin therapy. It remains uncertain whether cefprozil-associated serum sickness-like reaction represents a unique or a class-related adverse drug reaction.

Tétano / Tetanus

Os autores apresentam etiologia, sintomas, diagnósticos, diagnóstico diferencial e tratamento do tétano, e chamam a atençäo para os dados laboratoriais, terapêuticos e o prognóstico da doença.

Osteomielite / Osteomyelitis

Os autores chamam a atençäo para a etiologia, as formas clínicas da doença, bem como para os aspectos do tratamento. Descrevem ainda os sinais radiológicos, a patogenia e o diagnóstico da osteomielite