Inhibition of inducible nitric oxide synthase expression by interleukin-4 and interleukin-13 in human lung epithelial cells.

Oral feeding of proteins causes peripheral T-cell tolerance, as revealed by reduced delayed-type hypersensitivity (DTH) reactivity after immunization. This type of tolerance can be due both to passive T-cell anergy and active immunosuppression. Using ovalbumin-fed mice we studied whether putatively immunostimulatory cytokines could break this state of mucosal tolerance. Cytokines were administered locally at the site of attempted sensitization. It was found that neither interleukin-2 (IL-2), interferon-gamma (IFN-gamma) nor granulocyte-macrophage colony-stimulating factor (GM-CSF) could restore the response to immunization. In contrast, local administration of IL-12 at the site of attempted immunization resulted in full recovery of DTH reactivity. The dichotomy between the two Th1 stimulatory cytokines IFN-gamma and IL-12 was also reflected by different effects on ovalbumin-specific antibody isotypes. Although both IFN-gamma and IL-12 downregulated serum IgG1-levels in tolerant mice, suggesting decreased ovalbumin-specific Th2 function, only local administration of IL-12 led to increased serum IgG2a levels. These results support the view that potentiation of Th1 effector function is critical for reversal of mucosal tolerance.     

Confirmation of the autosomal recessive syndrome of ectopia lentis and distinctive craniofacial appearance

We report four members of a Lebanese Druze family with the syndrome of lens dislocation, spontaneous filtering blebs, anterior segment abnormalities, and a distinctive facial appearance. The constellation of clinical abnormalities in these patients is not suggestive of the Marfan syndrome or other connective tissue disorders associated with ectopia lentis. We previously described this syndrome in another presumably unrelated and highly inbred Druze family from the mountains of Lebanon. We postulated autosomal recessive inheritance in a pseudo-dominant pedigree. A few isolated reports of similar cases are scattered in the world literature. We now confirm that this is a distinct autosomal recessive syndrome whose gene mutation is enriched in the Lebanese Druze community.     

Respiratory mechanics and pleural remodelling in pleurodesis induced by barium sulphate

The aim of this study was to determine whether an intrapleural injection of barium sulphate would produce pleurodesis in rats. Additionally, respiratory mechanics and pleural remodelling were analysed. Single intrapleural injection of barium sulphate (100%) or saline was given to Wistar rats. Respiratory system, lung, and chest wall elastic, resistive and viscoelastic/inhomogeneous pressures were measured by the end-inflation occlusion method at 2 and 30 days after injection. The pleura were examined for gross and histopathological evidence of pleural inflammation and fibrosis, and the underlying lungs were also studied by morphometry. All pulmonary mechanical parameters increased at day 2, but were not different from control at 30 days after injection. Chest wall mechanical parameters did not change. Macroscopic evaluation demonstrated pleural adherence without haemothorax. Histopathologic analysis showed pleural inflammation and fibrosis. There was no alveolar inflammation or fibrosis in both groups. In conclusion, barium sulphate induced pleurodesis with either no changes in respiratory mechanics or lung lesion at day 30.     

Serologic and molecular investigations of a chimera

A chimeric individual possesses two or more genetically distinct cell populations. Although the chimerism may not be evident in all gene systems, various loci display greater numbers of alleles than genetically "normal" individuals. The proposita was referred for further laboratory investigation due to a mixed-field ABO blood group reaction following routine antenatal testing. Various molecular (HLA class II, ABO genotyping, and 10 short tandem repeat [STR] microsatellites) and serologic (HLA class I and red cell blood groups) typing techniques were employed to investigate a number of polymorphic loci located on different chromosomes. Chimerism was identified in 8 out of the 14 chromosomes tested: chromosome 1 (Duffy), 6 (HLA class I and II), 9 (ABO), 11 (HUMTH01), 12 (HUMPLA2A1), 15 (HUMFES/FPS), 18 (Kidd) and 21 (D21S11). The proposita was determined to be a probable dispermic chimera, based on the results of the serology and molecular studies.     

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...