The working mechanism of an immune complex vaccine that protects chickens against infectious bursal disease.

The role of immune complexes (Icx) in B-cell memory formation and affinity maturation allow for their potential use as vaccines. Recently, a new immune complex vaccine has been developed that is currently under field trials conducted in commercial poultry. This immune complex vaccine is developed by mixing live intermediate plus infectious bursal disease virus (IBDV) with hyperimmune IBDV chicken serum (IBDV-Icx vaccine). Here we have investigated the infectivity of this vaccine as well as the native IBDV (uncomplexed) vaccine in terms of differences in target organs, in target cells and speed of virus replication. At various days after inoculation on day 18 of incubation (in ovo) with either one dose of virus alone or the IBDV-Icx vaccine, the replication of IBDV and the frequency of B cells and other leucocyte populations were examined in the bursa of Fabricius, spleen, and thymus using immunocytochemistry. With both vaccines, IBDV was detected associated with B cells, macrophages and follicular dendritic cells (FDC) in bursa and spleen, although complexing IBDV with specific antibodies caused a delay in virus detection of about 5 days. Most remarkable was the low level of depletion of bursal and splenic B cells in IBDV-Icx vaccinated chickens. Furthermore, in ovo inoculation with the IBDV-Icx vaccine induced more germinal centres in the spleen and larger amounts of IBDV were localized on both splenic and bursal FDC. From these results we hypothesize that the working mechanism of the IBDV-Icx vaccine is related to its specific cellular interaction with FDC in spleen and bursa.     

Membrane ionic currents and properties of freshly dissociated rat brainstem neurons

It is well known that neuronal firing properties are determined by synaptic inputs and inherent membrane functions such as specific ionic currents. To characterize the ionic currents of brainstem cardio-respiratory neurons, cells from the hypoglossal (XII) nucleus and the dorsal motor nucleus of the vagus (DMX) were freshly dissociated and membrane ionic currents were studied under whole-cell voltage and current clamp. Both of these neurons showed a TTX-sensitive Na⁺ current with a much larger current density in XII than DMX neurons. This Na⁺ current had two (fast and slow) distinct inactivation decay components. The ratio of the magnitudes of the fast to slow component was roughly two-fold greater in DMX than in XII cells. Both DMX and XII neurons also showed a high voltage-activated Ca²⁺ current, but this current density was significantly greater (three-fold) in DMX than XII neurons. A relatively small amount of low-voltage activated Ca²⁺ current was also observed in DMX neurons, but not in the majority of XII cells. A transient and a sustained outward current components were observed in DMX cells, but only sustained currents were present in XII neurons. These outward currents had a reversal potential of about − 70 mV with 3 mM external K⁺ and −30 mV with 25 mM K⁺, and substitution of K⁺ with cesium and tetraethylammonium suppressed more than 90% the outward currents, indicating that most outward currents were carried by K⁺. The transient outward current consisted of two components with onesensitive to 4-aminopyridine and the other to intracellular Ca²⁺. In XII neurons, BRL 38227 (lemakalim), an ATP-sensitive K⁺ (K_ATP) channel activator, increased the sustained K⁺ currents by 10% of control, and glibenclamide, a K_ATP channel blocker, decreased the sustained K⁺ currents by 20%. Evidence for the presence of an inward rectifier K⁺ current was also obtained from both XII and DMX neurons. These results on XII and DMX neurons indicate that (1) the methods used to dissociate neurons provide a useful means to overcome voltage clamp technical difficulties; (2) ion channel characteristics such as density and biophysical properties of DMX neurons are very different from those of XII neurons; and (3) several newly discovered membrane ionic currents are present in these cells.     

Conjunctival granuloma caused by synthetic fibers

Histopathological examination of a conjunctival lesion occurring in a two-and-a-half-year-old boy revealed granulomatous inflammation surrounding filamentous foreign material. The main type of fiber was fairly uniform in diameter, generally round to oval in cross-section, with vivid birefringence, manifesting a "cracking phenomenon" and lacking a central core. These findings are typical of synthetic fibers. Synthetic fiber granulomas often occur in children, predominantly unilaterally. Comforting blankets, fabric toys or forcibly applied pullovers may cause initial inoculation.     

Health Literacy and Associated Outcomes in the Postpartum Period at Grady Memorial Hospital

Maternal and Child Health Journal - Many studies correlate lower health literacy with poorer health outcomes and inferior provider-patient communication. Little is known about how impaired health...     

Validation of low-cost models for minimal invasive surgery training of congenital diaphragmatic hernia and esophageal atresia

BackgroundMinimal invasive surgery (MIS) is increasingly used for the correction of congenital diaphragmatic hernia (CDH) and esophageal atresia (EA). It is important to master these complex procedures, preferably preclinically, to avoid complications. The aim of this study was to validate recently developed models to train these MIS procedures preclinically.MethodsTwo low cost, reproducible models (one for CDH and one for EA) were validated during several pediatric surgical conferences and training sessions (January 2017–December 2018), used in either the LaparoscopyBoxx or EoSim simulator. Participants used one or both models and completed a questionnaire regarding their opinion on realism (face validity) and didactic value (content validity), rated on a five-point-Likert scale.ResultsOf all 60 participants enrolled, 44 evaluated the EA model. All items were evaluated as significantly better than neutral, with means ranging from 3.7 to 4.1 (p < 0.001). The CDH model was evaluated by 48 participants. All items scored significantly better than neutral (means 3.5–3.9, p < 0.001), with exception of the haptics of the simulated diaphragm (mean 3.3, p = 0.054). Both models were considered a potent training tool (means 3.9).ConclusionThese readily available and low budget models are considered a valid and potent training tool by both experts and target group participants.Type of studyProspective study.Level of evidenceLevel II.     

Qualité des supports de communication de crise lors de la pandémie de la COVID-19 au Grand Maghreb

ObjectiveTo objectively assess the quality of “crisis communication” media, during the COVID-19 pandemic, in the three Greater Maghreb countries (Tunisia, Algeria, Morocco).MethodsA compliance audit for press releases and epidemiological bulletins was analyzed against a quality benchmark, which had been specifically designed by the authors. This framework, made up of five dimensions and 50 items, graded (0/1), was applied by two researchers in preventive medicine. Multiplying the scores by a coefficient of two resulted in a partial score of 20 points for each dimension and a total score of 100 points for the checklist taken as a whole. The quality of the communication media was considered to be good when exceeding the thresholds of 15/20 for the different dimensions and 75/100 for the entire grid.ResultsA total of 141 information media were included in this audit (Tunisia: 60; Algeria: 60; Morocco: 21). The overall median quality score for these media was only 56/100 (IIQ: [46–58]), without major variability between countries. The most appreciated dimension was “maintaining the confidence of the population”, with an overall median score of 14/20 (12/20 for epidemiological bulletins and 16/20 for press releases). The most poorly rated dimension was “strengthening community participation”, with a median score of only 4/20 (6/20 for epidemiological bulletins and 4/20 for press releases).ConclusionThe quality of the Maghreb crisis communication media during COVID-19 was insufficient in most of its dimensions and items, particularly from a psychosocial standpoint. Reinforcement of the capacities of communication officers to develop information material and supports during health crises is indispensable and should be considered as an urgent matter.     

Osteosarcomatosis

A review of the 690 cases of osteosarcoma in the radiographic file of the Armed Forces Institute of Pathology revealed 29 cases of "osteosarcomatosis" (multiple skeletal sites of osteosarcoma). Fifteen of these patients were 18 years old and under and manifested rapidly appearing, usually symmetric, sclerotic metaphyseal lesions. The remaining 14 patients were more than 18 years old and had fewer, asymmetric sclerotic lesions. In most patients (28 of 29), a radiographically dominant skeletal tumor was seen. Pulmonary metastases occurred in the majority of patients and were detected at the same time as the bone lesions. These 29 patients were studied with regard to demographic data and skeletal distribution and radiographic appearance of their lesions. As a result of the findings, a metastatic origin from a primary dominant osteosarcoma is favored over a multifocal origin as the basis for osteosarcomatosis. Osteosarcomatosis is more commonly encountered in the mature skeleton than has been previously recognized.