Mast cell populations in the chick embryo lung and their response to compound 48/80 and dexamethasone

Summary Two mast cell populations, connective tissue mast cells (CTMCs) and mucosal mast cells, (MMCs) containing different proteoglycans in their granules, can be distinguished in several animal species by means of histochemical methods. In this study we documented the presence of these two types of mast cell in the chick embryo lung, from the 15th incubation day for the MMCs, and from the 18th incubation day for the CTMCs. Lungs of embryos treated with compound 48/ 80, which produces degranulation of the CTMCs, showed a decrease in the number of this type of mast cell and an unchanged number of MMCs. In the lungs of embryos treated with dexamethasone, which degranulates MMCs, a reduction in the number of these cells and an unchanged number of the CTMs were found.     

Physiological and Psychological Effects of Delivering Medical News Using a Simulated Physician–Patient Scenario

We examined the acute stress response associated with having to deliver either bad or good medical news using a simulated physician–patient scenario. Twenty-five healthy medical students were randomly assigned to a bad medical news (BN), a good medical news (GN), or a control group that read magazines during the session. Self-report measures were obtained before and after the task. Blood pressure and heart rate were measured throughout the task period. Four blood samples were obtained across the task period. The BN and GN tasks produced significant increases in self-reported distress and cardiovascular responses compared with the control group. There was also a significant increase in natural killer cell function 10 min into the task in the BN group compared with the control group. The BN task was also somewhat more stressful than the GN task, as shown by the self-report and cardiovascular data. These findings suggest that a simulated physician–patient scenario produces an acute stress response in the physician, with the delivery of bad medical news more stressful than the delivery of good medical news.     

Identification of dermatophyte species by 28S ribosomal DNA sequencing with a commercial kit

We have shown that dermatophyte species can be easily identified on the basis of a DNA sequence encoding a part of the large-subunit (LSU) rRNA (28S rRNA) by using the MicroSeq D2 LSU rRNA Fungal Sequencing Kit. Two taxa causing distinct dermatophytoses were clearly distinguished among isolates of the Trichophyton mentagrophytes species complex.     

Primary Immunodeficiency Diseases in Latin America: First Report from Eight Countries Participating in the LAGID

The Latin American Group for Primary Immunodeficiencies, formed in 1993, presently includes 12 countries. One goal was to study the frequency of primary immunodeficiencies in various regions of the American continent and to enhance knowledge about these diseases among primary-care physicians, as well as allergist–immunologists. Important for this purpose was the development of a registry of primary immunodeficiencies using a uniform questionnaire and computerized database. To date, eight countries have collected information on a total of 1428 patients. Predominantly antibody deficiencies were reported in 58% of patients, followed by cellular and antibody immunodeficiencies associated with other abnormalities in 18%, immunodeficiency syndromes associated with granulocyte dysfunction in 8%, phagocytic disorders in 9%, combined cellular and antibody immunodeficiencies in 5%, and complement deficiencies in 2% of patients. The information gathered from this initial analysis of data will serve to expand the patient database to more areas within participating countries and to new countries and to increase collaboration toward better diagnosis and treatment of these diseases.     

Impaired macrophage responses may contribute to exacerbation of blood-stage Plasmodium chabaudi chabaudi malaria in interleukin-12-deficient mice.

Aiming to clarify the role of endogenous interleukin-12 (IL-12) in protective immunity against blood stages of Plasmodium chabaudi chabaudi (AS), we evaluated the course of infection in IL-12p40 gene knockout (IL-12p40KO) and wild-type (WT) C57BL/6 mice, focusing (1) on the ability of T cells to develop adequate type 1 responses and (2) on the potentiality of macrophages to respond to parasites, interferon-gamma (IFN-gamma), or both. We observed that IL-12p40KO mice develop significantly higher parasitemias during the acute infection, although mice from both groups clear the parasites within a month and similarly eliminate a secondary challenge. Thus, fully protective immunity to P. c. chabaudi can be generated in the absence of IL-12. However, this cytokine may promote parasite control during the early phase of infection. The increased acute parasitemia of IL-12p40KO mice was associated with both impaired IFN-gamma and nitric oxide (NO) response by spleen cells. Because stimulation with recombinant IFN-gamma (rIFN-gamma) failed to improve the NO response in IL-12p40KO macrophages, we investigated whether these cells have an intrinsic defect. Analysis of peritoneal macrophages revealed that IL-12p40KO cells produce higher levels of transforming growth factor-beta1 (TGF-beta1) compared with WT cells and respond to infected erythrocytes or rIFN-gamma by releasing little NO. Moreover, IL-12p40KO macrophages had a severely impaired ability to internalize opsonized infected erythrocytes, suggesting that the low effector profile assumed by these cells may compromise antibody-mediated immunity. Taken together, our results support the idea that the absence of IL-12p40 not only affects IFN-gamma production but also has deep consequences in macrophage effector functions that may contribute to exacerbation of the early phase of P. c. chabaudi malaria.     

Morphological observations and morphometric analysis in three human fetuses with bilateral cervical cystic hygroma

Three human fetuses (crown-rump length, CRL, ranging from 71 to 77 mm), presenting bilateral cervical cystic hygroma were examined. The specimens were cleared and double-stained with alcian blue and alizarin red S for detecting the ossification growth patterns in the vertebral column, ribs, ischium, limbs, and face. Longitudinal measurements of some long bones in the upper (humerus, ulna, radius) and lower (femur, tibia, fibula) limb were taken. The values of both the total length (TL) and the ossified part (OL) of each long bone, as well as the OL/TL per cent ratio were considered. Reference points were located on the mandible, i.e. condylar process (Pcl), coronoid process (Pco), gnathion (GN), gonion (GO), inferior interdental point (IDI) for measuring linear dimensions. All values obtained were related with those relative to a group of fetuses, without any detectable malformation and chromosomal abnormalities, with CRL mean value 75 mm, in order to assess the presence of further anomalies, besides the cystic hygroma, in the three fetuses considered.