Schistosoma mansoni control in Cul de Sac valley,Saint Lucia. II. Chemotherapy as a supplement to a focal mollusciciding programme

After an intensive area-wide mollusciciding campaign, over four and a half years, transmission of Schistosoma mansoni was reduced. A cheaper scheme suitable for the follow-up or consolidation stage of control was evaluated and two selective population chemotherapy campaigns using hycanthone (2 mg/kg b.w.) and oxamniquine (15 mg/kg b.w.) were mounted. Prevalence dropped to 6% and 3% in areas with previously high and low levels of transmission respectively. Calculations suggested that these figures were falsely low and that perhaps 20% of the population were still excreting S. mansoni ova in small numbers. The unco-operative groups in the population are probably more important in maintaining a reservoir of infection in the community than persons with light infections undetected by the sedimentation concentration stool examination technique used. The benefit of more sensitive but more costly examination techniques is not clear since the importance of very light infections in transmission is uncertain. Case detection absorbs an increasing proportion of the total cost of chemotherapy programmes with fewer cases being found amongst the same number screened. Using hycanthone (649 treated) the cost per person protected was $0·74 and using oxamniquine (264 treated) $0·94. The need to develop low cost consolidation or follow-up procedures for preventing a resurgence of transmission after successful control, when the infection is no longer of public health importance, is stressed.     

Embryoid body morphology influences diffusive transport of inductive biochemicals: a strategy for stem cell differentiation

Differentiation of human embryonic stem (hES) cells into cells for regenerative medicine is often initiated by embryoid body (EB) formation. EBs may be treated with soluble biochemicals such as cytokines, growth factors and vitamins to induce differentiation. A scanning electron microscopy analysis, conducted over 14 days, revealed time-dependent changes in EB structure which led to the formation of a shell that significantly reduced the diffusive transport of a model molecule (374 Da) by >80%. We found that the shell consists of 1) an extracellular matrix (ECM) comprised of collagen type I; 2) a squamous cellular layer with tight cell-cell adhesions associated with E-cadherin; and 3) a collagen type IV lining indicative of a basement membrane. Disruption of the basement membrane, by either inhibiting its formation with noggin or permeabilizing it with collagenase, resulted in recovery of diffusive transport. Increasing the diffusive transport of retinoic acid (RA) and serum in EBs by a 15-min collagenase digestion on days 4, 5, 6 and 7 promoted neuronal differentiation. Flow cytometry and quantitative RT-PCR analysis of collagenase-treated EBs revealed 68% of cells expressing neural cell adhesion molecule (NCAM) relative to 28% for untreated EBs. Our results suggest that limitations in diffusive transport of biochemicals need to be considered when formulating EB differentiation strategies.     

Characterization and partial purification from pheochromocytoma cells of an endogenous equivalent of scyllatoxin, a scorpion toxin which blocks small conductance Ca-activated K channels

This work describes the partial purification of a heat-stable peptide which has the same properties as the scorpion toxin, scyllatoxin, a specific blocker of one class of Ca²⁺-activated K⁺ channels: (i) it competes with [¹²⁵I]apamin for binding to the same site, (ii) like apamin and scyllatoxin, it blocks the after-potential hyperpolarization in skeletal muscle cells in culture, (iii) like apamin and scyllatoxin, it contracts guinea-pig tnia coli relaxed by epinephrine, (iv) it cross-reacts with antibodies raised against scyllatoxin but not with antibodies raised against apamin.     

Solitary azygos prolongation (author's transl)

Azygos prolongation of the inferior vena cava is a congenital abnormality which is normally associated with a congenital cardiac lesion, abnormalities of the inferior caval system and, in some instances, abdominal heterotaxia. The authors report here a case which is exceptional in the sense that the azygos prolongation was isolated. Further radiological studies are essential in order to make the diagnosis following the discovery of a right-sided laterotracheal opacity on a plain chest film. Only five other cases were found in the literature.     

The simulation of an ex utero intrapartum procedure to extracorporeal membrane oxygenation

We report a case of using simulation to aid in the performance of ex utero intrapartum treatment (EXIT) procedure to extracorporeal membrane oxygenation (ECMO). A primigravid with a fetus who was diagnosed with hypoplastic left heart syndrome was scheduled for an EXIT to ECMO procedure to be done by members of her obstetrical and neonatal teams. It would be the first time any of the members of the 2 teams would work together. Simulation was used to allow all involved parties to experience the procedure before the live operation. In addition, the simulation enabled the interdisciplinary teams to work with each other, identify possible complications, and further plan the coordination during the event. The EXIT to ECMO surgery was completed successfully. The use of low-fidelity, cost-effective simulation during a surgical rehearsal can give a surgical team critical advantage when performing a rare and/or complex procedure.     

Kolloidchemische Analyse der Anaphylaktischen Präcipitation

Ohne Zusammenfassung     

Über das Durch Kaolin Oder Stärke Erzeugte Sogenannte „Anaphylatoxin“

Ohne Zusammenfassung