Transport of electrolytes and water in the upper jejunum of the fowl in vivo perfusion

The mechanism(s) of electrolytes (J _Na,J _Cl,J _Ca andJ _K) and water transport (J _v) were studied in the upper jejunum of the laying hen by an in vivo perfusion procedure. Water secretion is modified by the difference of osmotic pressure between the lumen and plasma and we have estimated the osmotic permeability coefficient (P osm=17.4 l×h^–1×mosm^–1×g^–1 DW) and the reflexion coefficient (0.72). At sodium concentrations of 0 and 80 mM×l^–1 in the lumen, there is a large secretion of Na. When the water flow is modified by osmotic pressure, this secretion is markedly influenced byJ _v. Similarly net chloride flux occurred mainly by solvent drag.Conversely water flow does not modify the large potassium absorption along the concentration gradient and only slightly affects the flux of calcium. Transport of calcium occurred along the gradient of concentration between lumen and plasma without saturation until a lumen concentration of 20 mM×l^–1. This driving force seemed to be the main one sinceJ _Ca is close to zero when these is no gradient. This observation supports the hypothesis that the variations of net Ca absorption during the laying cycle is due to a modification of concentration of soluble calcium in the contents of the intestine.     

DEATH AS A STIMULUS TO IMPROVING THE AFRICAN ENVIRONMENT FOR MORE HEALTHFUL LIVING

In D. Leviton's (1991) conception of horrendous death , a poorly managed environment can contribute to widespread mortality, and the deaths so caused can further create an environment for subsequent death. The African environment in particular is characterized by a number of "deathogenic" factors that must be understood and confronted by health educators committed to minimizing or eliminating the impact of horrendous death on the African continent. In this comment, the author argues that attention to characteristic but preventable forms of death in the African context can lead to greater public advocacy among African health educators, contributing to the physical and psychological wellbeing of the populations they serve.     

Comparison of relative and actual chest compression depths during cardiac arrest in children, adolescents, and young adults

Aim

Cardiopulmonary resuscitation (CPR) guidelines recommend specific chest compression (CC) target depths for children. We quantitatively describe relative anterior–posterior diameter (APD) depth, actual depth, and force of CCs during real CPR events in children.

Methods

CC depth and force were recorded during real CPR events in children ≥8 years using FDA-approved CC sensor. Patient chest APD was measured at conclusion of each CPR event. CC data was stratified and analyzed according to age (pre-puberty, 8–14 years; post-puberty, 15+ years). Relative (% APD) and actual CC depth, corrected for mattress deflection, were assessed and compared with American Heart Association (AHA) 2005 and 2010 pediatric CPR guidelines.

Results

35 events in 32 subjects included 16,158 CCs for data analysis: 16 pre-puberty (CCs = 7484, age 11.9 ± 2 years, APD 164.6 ± 25.1 mm); 19 post-puberty (CCs = 8674, age 18.0 ± 2.7 years, APD 196.5 ± 30.4 mm). After correction for mattress deflection, 92% of CC delivered to pre-puberty were <1/3 relative APD and 60% of CC were <38 mm actual depth. Mean actual CC depth (36.2 ± 9.6 mm vs. 36.8 ± 9.9 mm, p = 0.64), mean relative APD (22.5% ± 7.0% vs. 19.5 ± 6.7%, p = 0.13), and mean CC force (30.7 ± 7.6 kg vs. 33.6 ± 9.4 kg, p = 0.07) were not significantly less in pre-puberty vs. post-puberty.

Conclusions

During in-hospital cardiac arrest of children ≥8 years, CCs delivered by resuscitation teams were frequently <1/3 relative APD and <38 mm actual depth after mattress deflection correction, below pediatric and adult target guidelines. Mean CC actual depth and force were not significantly different in pre-puberty and post-puberty. Additional investigation to determine depth of CCs to optimize hemodynamics and outcomes is needed to inform future CPR guidelines.     

Interferon-γ and interleukin-4 reciprocally regulate the production of monocytes/macrophages and neutrophils through a direct effect on committed monopotential bone marrow progenitor cells

We studied the direct effects of interferon-γ (IFN-γ) in single cell colony assays of CD34⁺HLA-DR++ bone marrow progenitor cells stimulated by either granu-locyte-colony-stimulating factor (G-CSF), interleukin(IL)-3, granulocyte/macro-phage-colony-stimulating factor (GM-CSF), combinations of these CSF or medium conditioned by the 5637 human bladder carcinoma cell line. In this culture system IFN-γ stimulated monocytic colonies (CFU-M) no matter which CSF or CSF combination was used to support them and inhibited granulocytic colonies (CFU-G) if they were generated in the presence of G-CSF. IL-4 antagonized the myelopoietic effects of IFN-γ: the IFN-γ induced suppression of G-CSF-supported CFU-G, as well as the stimulation of CFU-M, were reversed by IL-4. In all cultures, IFN-γ had a limited, but statistically non-significant, inhibitory effect on CFU-GM, which was not affected by the presence of IL-4. These data show that IFN-γ and IL-4 reciprocally regulate the generation of myeloid cells involved in humoral (neutrophils) and cellular (macrophages) immune responses through a direct effect on monopotential myeloid progenitor cells.     

Infectious virus titer,replicative and syncytium-inducing capacity of human immunodeficiency virus type 1

The relationship was investigated between a viral infectious titer in peripheral blood mononu-clear cells (PBMC) and plasma on the replicative and syncytium-inducing capacity of human immunodeficiency virus type 1 (HIV-1) isolates. The replicative capacity was defined as the minimum time required for p24 antigen to become positive in PBMCs or plasma of HIV-1 infected individuals, cocultured with PBMCs of healthy donors. Syncytium induction was determined by the MT-2 cell assay and defined as the presence of giant multinucleated cells. The replicative capacity of HIV-1 in PBMCs of healthy donors correlated with the infectious viral titer in PBMCs, but not in the plasma of HIV-1 positive patients. Syn-cytia formation in MT-2 cells was not related to the infectious viral titer in PBMCs or plasma of HIV-1 positive patients. These findings suggest that syncytium formation, not replicative capacity, is an intrinsic HIV-1 phenotype. © 1995 Wiley-Liss, Inc.     

Genotyping hepatitis C viruses from Southeast Asia by a novel line probe assay that simultaneously detects core and 5' untranslated regions

Hepatitis C viruses (HCVs) display a high level of sequence diversity and are currently divided into six genotypes. A line probe assay (LiPA), which targets the 5' untranslated region (5'UTR) of the HCV genome, is widely used for genotyping. However, this assay cannot distinguish many genotype 6 subtypes from genotype 1 due to high sequence similarity in the 5'UTR. We investigated the accuracy of a new generation LiPA (VERSANT HCV genotype 2.0 assay), in which genotyping is based on 5'UTR and core sequences, by testing 75 selected HCV RNA-positive sera from Southeast Asia (Vietnam and Thailand). For comparison, sera were tested on the 5'UTR based VERSANT HCV genotype assay and processed for sequence analysis of the 5'UTR-to-core and NS5b regions as well. Phylogenetic analysis of both regions revealed the presence of genotype 1, 2, 3, and 6 viruses. Using the new LiPA assay, genotypes 6c to 6l and 1a/b samples were more accurately genotyped than with the previous test only targeting the 5'UTR (96% versus 71%, respectively). These results indicate that the VERSANT HCV genotype 2.0 assay is able to discriminate genotypes 6c to 6l from genotype 1 and allows a more accurate identification of genotype 1a from 1b by using the genotype-specific core information.