Assessing the long-term effects of zero-tillage on the macroporosity of Brazilian soils using X-ray Computed Tomography.

Zero-tillage (ZT) is being increasingly adopted globally as a conservationist management system due to the environmental and agronomic benefits it provides. However, there remains little information on the tillage effect on soil pore characteristics such as shape, size and distribution, which in turn affect soil physical, chemical and biological processes. X-ray micro Computed Tomography (µCT) facilitates a non-destructive method to assess soil structural properties in three-dimensions. We used X-ray µCT at a resolution of 70 µm to assess and calculate the shape, size and connectivity of the pore network in undisturbed soil samples collected from a long-term experiment (~30 years) under zero tillage (ZT) and conventional tillage (CT) systems in Botucatu, Southeastern Brazil. In both systems, a single, large pore (>1000 mm3) typically contributed to a large proportion of macroporosity, 91% in CT and 97% in ZT. Macroporosity was higher in ZT (19.7%) compared to CT (14.3%). However the average number of pores was almost twice in CT than ZT. The largest contribution in both treatments was from very complex shaped pores, followed by triaxial and acircular shaped. Pore connectivity analysis indicated that the soil under ZT was more connected that the soil under CT. Soil under CT had larger values of tortuosity than ZT in line with the connectivity results. The results from this study indicate that long-term adoption of ZT leads to higher macroporosity and connectivity of pores which is likely to have positive implications for nutrient cycling, root growth, soil gas fluxes and water dynamics.

Tigeciclina versus vancomycin más aztreonam en el tratamiento de infecciones complicadas de piel y tejidos blandos: Experiencia en Latinoamérica / Tigecycline as effective as vancomycin plus aztreonam in the treatment of complicated skin and skin structure infections: Experience in Latin America

BACKGROUND: Treating complicated skin and skin structure infections (cSSSIs) can be challenging. Tigecycline was compared to vancomycin/aztreonam in patients with cSSSIs in a multinational trial; this article reports on the Latin American (LA) population. METHODS: Patients were randomly assigned to receive tigecycline or vancomycin/ aztreonam. Primary endpoint was clinical cure rate at test-of-cure (TOC). Several secondary endpoints and safety were also assessed. RESULTS: A subtotal of 167 LA patients from the multinational trial (N = 573) received ≥ 1 dose of study drug. At TOC, cure rates were similar between tigecycline and vancomycin/aztreonam in the clinically evaluable population.) Noninferiority of tigecycline could not be demonstrated (insufficient sample sizes). Tigecycline-treated patients had higher incidences of nausea, vomiting, anorexia; vancomycin/aztreonam-treated patients had higher incidences of pruritus and rash. CONCLUSIONS: Efficacy results in the LA population were consistent with the multinational study suggesting that tigecycline is noninferior to vancomycin/aztreonam in treating patients with cSSSI.

INTRODUCCIÓN: El tratamiento de infecciones complicadas de piel y tejidos blandos (ICPTB) puede representar un desafío. Se comparó la eficacia de tigeciclina versus vancomicina/aztreonam en pacientes con ICPTB en un estudio multicéntrico; este artículo se refiere a la experiencia en Latinoamérica (LA). MÉTODO: Se asignaron, en forma randomizada, los pacientes a dos grupos de tratamiento: tigeciclina o vancomicina/aztreonam. La meta a evaluar (outcome) primaria fue la curación clínica, denominada test de curación (TC). Se establecieron, además, metas secundarias y la evaluación de seguridad del fármaco. RESULTADOS: Un subtotal de 167 pacientes procedentes de LA, de un estudio multinacional que incluyó 573 pacientes, recibieron ≥ 1 dosis del fármaco en estudio. Al TC, los porcentajes de curación fueron similares entre tigeciclina y vanco-micina/aztreonam en los pacientes clínicamente evaluables). La no inferioridad de tigeciclina no pudo ser demostrada (tamaño de muestra insuficiente). Los pacientes tratados con tigeciclina tuvieron mayor incidencia de náuseas, vómitos y anorexia; los pacientes que recibieron vancomicina/aztreonam tuvieron mayor incidencia de prurito y rash. CONCLUSIONES: Los resultados de eficacia en LA fueron consistentes con el estudio multinacional sugiriendo que tigeciclina no es inferior a vancomicina/aztreonam en el tratamiento de pacientes con ICPTB.

Seroprevalence of human herpesvirus-8 (HHV-8) in countries of Southeast Asia compared to the USA, the Caribbean and Africa

Seroprevalence of HHV-8 has been studied in Malaysia, India, Sri Lanka, Thailand, Trinidad, Jamaica and the USA, in both healthy individuals and those infected with HIV. Seroprevalence was found to be low in these countries. In contrast, the African countries of Ghana, Uganda and Zambia showed high seroprevalences in both healthy and HIV-infected populations. This suggests that human herpes virus-8 (HHV-8) may be either a recently introduced virus or one that has extremely low infectivity. Nasopharyngeal and oral carcinoma patients from Malaysia, Hong Kong and Sri Lanka who have very high EBV titres to show that only 3/82 (3.7 percent) have antibody to HHV-8, demonstrating that there is little, if any, cross-relativity between antibodies to these two gamma viruses. (AU)

Use of health services by children and young people according to ethnicity and social class: secondary analysis of a national survey.

OBJECTIVE: To assess whether equity is achieved in use of general practitioner, outpatient, and inpatient services by children and young people according to their ethnic group and socioeconomic background. DESIGN: Secondary analysis of the British general household survey, 1991-94. SUBJECTS: 20 473 children and young people aged between 0 and 19 years. MAIN OUTCOME MEASURES: Consultations with a general practitioner within a two week period, outpatient attendances within a three month period, and inpatient stays during the past year. RESULTS: There were no significant class differences in the use of health services by children and young people, and there was little evidence of variation in use of health services according to housing tenure and parental work status. South Asian children and young people used general practitioner services more than any other ethnic group after controlling for socioeconomic background and perceived health status, but the use of hospital outpatient and inpatient services was significantly lower for children and young people from all minority ethnic groups compared with the white population. CONCLUSIONS: Our results differ from previous studies, which have reported significant class differences in use of health services for other age groups. We found no evidence that children and young people's use of health services varied according to their socioeconomic status, suggesting that equity has been achieved. A child or young person's ethnic origin, however, was clearly associated with use of general practitioner and hospital services, which could imply that children and young people from minority ethnic groups receive a poorer quality of health care than other children and young people.

Risk factors for recurrent fever after the discontinuation of empiric antibiotic therapy for fever and neutropenia in pediatric patients with a malignancy or hematologic condition.

We studied episodes of fever and neutropenia in children and adolescents without documented infections to determine the risk of recurrent fever after early discontinuation of empiric antibiotic therapy; 213 episodes occurred in 106 patients. All patients received empiric antibiotic therapy after cultures were obtained. Antibiotic therapy was discontinued if no infection was found, culture results were negative for 48 hours, and the patient was afebrile for 24 hours. In 83 episodes without documented infection, antibiotic therapy was stopped with absolute neutrophil counts < 0.5 x 10(9)/L (< 500/mm3); 50 episodes occurred in patients with solid tumors, leukemia in remission, and other hematologic conditions (group 1), and 33 in patients with active leukemia (group 2). Fever recurred before neutropenia resolved in 6% of group 1 and 45% of group 2 episodes; five patients in group 2 had documented infection. Recurrent fever risk correlated with absolute neutrophil count and monocyte count at the time antibiotic therapy was stopped, in both groups, as did increasing absolute neutrophil count and increasing leukocyte count in group 2. We conclude that discontinuing antibiotic therapy is safe in febrile episodes without documented infections before neutropenia resolves in patients with high potential for bone marrow recovery. The risk of recurrent fever and infection is significant for patients with neutropenia and poor marrow recovery potential.