The effect of okadaic acid on histamine release, cell morphology and phosphorylation in rat basophilic leukemia (RBL-2H3) cells, human basophils and rat peritoneal mast cells

To study the involvement of serine/threonine phosphatase in the signal transduction of mast cells, we examined the effects of okadaic acid (OA), an inhibitor of type-1 and -2A phosphatase on histamine release, cell morphology, calcium influx and protein phosphorylation of rat basophilic leukemia (RBL-2H3) cells, human basophils and rat peritoneal mast cells. OA inhibited IgE-mediated histamine release from RBL-2H3 cells and human basophils dose-dependently. There was a remarkable enhancement of IgE-mediated histamine release when rat peritoneal mast cells were suboptimally challenged. OA induced a marked change of cell features, detached RBL-2H3 cells from plastic well and kept the 18- and 68-kD proteins phosphorylated. These findings show that phosphatase may play a role in the modulation of secretion in mast cells.     

Influence of serum-free culture conditions on subcellular localization of steroid 5alpha-reductase in rat C6 glioma cells

Rat C6 glioma cells are considered to be well characterized, and therefore commonly used as a model system to investigate the function of glial cells. However, recent study has shown that an alteration in the expression of their phenotypic antigens is observed when the cells are maintained under the serum-free conditions, proposing the possibility that various properties of glioma cells can be altered by the growth conditions. To test this possibility, the effects of serum-free culture conditions on the expression of steroid 5alpha-reductase (5alpha-R) type 1 isozyme in glioma cells were examined using immunocytochemical technique. Immunoreactivity of 5alpha-R type 1 was confined to the perinuclear region of glioma cells cultured in serum-containing medium, and observed in the cytoplasmic space as well as the perinuclear region of the cells cultured in serum-free medium. In contrast, serum deprivation failed to affect the expression of phenotypic antigens, glial fibrillary acidic protein (GFAP) and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase). Further studies showed that the expression of cytoplasmic 5alpha-R immunoreactivity induced by serum deprivation was reversible, and might be attributed to removal of serum proteins rather than biologically active small molecules from culture medium. This alteration in the expression of 5alpha-R immunoreactivity is therefore considered to reflect the translocation of the enzyme from the perinuclear region to the cell cytoplasm rather than the induction of cytoplasmic enzyme, and suggest that the culture conditions cause an alteration in the subcellular localization of 5alpha-R type 1 isozyme without phenotypic change of the glioma cell.     

Involvement of adenosine in vanadate-stimulated release of lipoprotein lipase activity

BACKGROUND: Optimal bottle weaning should occur between 12 and 15 months of age. We hypothesized that high-risk populations have different parental attitudes, learned behaviors, and knowledge of weaning practices. OBJECTIVE: To determine whether high-risk populations are less likely to wean their children by 15 months of age than low-risk populations. METHODS: A cross-sectional survey using a convenience sample of parents was conducted at 3 community-based pediatric clinics. Spanish- and English-speaking parents with weaned and unweaned children 12 to 36 months of age were included in the study. A self-administered questionnaire was completed at a clinic visit. The questionnaire addressed aspects of parents' sociodemographic characteristics and included feeding history; weaning practices; sources of information about weaning; and parental behaviors, attitudes, and knowledge of age at which the child should be weaned. RESULTS: One hundred eighty questionnaires were completed. Marital status was related to weaning behavior. Seventy-six percent of single mothers had weaned their children in a timely manner, whereas 48% of married mothers had done so (chi2 = 7.70; P = .008). Parental education, race, and income were not significantly related to the timeliness of weaning. When respondents rated the helpfulness of multiple sources, only the health clinic was found to be significantly more important for the timely weaning group (t = -2.13; P = .04). Parents with timely weaned children stated that the mean +/- SD optimal age for weaning is 13.6 +/- 3.2 months. Parents with unweaned and late-weaned children stated that the mean +/- SD optimal age is 19.9 +/- 6.6 months. Bedtime bottle feedings were reported in more than 87% of the unweaned group. Sixty-nine percent reported poor dental development associated with delayed weaning. CONCLUSIONS: Married parents are at risk of late weaning. Parents continue to allow their children to sleep with milk bottles in their mouths in bed at night. Parents are not aware of the medical problems associated with late weaning. Late-weaning parents are not knowledgeable about current weaning recommendations. Current approaches are not effective in altering set patterns of inappropriate weaning habits. Additional interventions and innovative parental education methods are needed to improve age-appropriate weaning practices.     

Nonsurgical treatment of congenital clubfoot with manipulation, cast, and modified Denis Browne splint

The purpose of this presentation is to concentrate on three issues: Is there an explanation for the large difference in reported incidence rates of inhibitor formation in haemophiliacs? Why do not all severe patients develop inhibitors? And how on the contrary do some patients with mild haemophilia develop inhibitors?     

Laparoscopic gastric devascularization and splenectomy for sclerotherapy-resistant esophagogastric varices with hypersplenism

BACKGROUND: Cervical cancer is the most important cancer in Mexican women. Early detection is possible by means of the Papanicolaou (Pap) test; however, the coverage in Mexico is low. METHODS: A cross-sectional survey was carried out in a representative sample of women from the Tlalpan area of Mexico City. Social, reproductive and health care factors associated with the lack of use of the Pap test with respect to adequate use and misuse were identified. Both bivariate and logistic regression analyses were used for the adjustment of variables. RESULTS: Of 1,215 women studied, 22.5% had never had a Pap smear, 42% had misused the test (< 90% of triennial performance), and 35.5% had adequately used the test (> or = 90% of triennial performance). The main factors related to the lack of use were the following: not knowing about the Pap test (ORa = 35.16, 95% C.I. = 17.4-70.9); having fewer than 6 years of education (ORa = 4.5, 95% C.I. = 2.5-8.4); women younger than 30 years of age (ORa = 3.4 95% C.I. = 2.3-5.1); use of contraceptives (ORa = 0.4, 95% C.I. = 0.2-0.8); history of sexually transmitted diseases (ORa = 0.3, 95% C.I. = 0.1-0.8), and the principal informant about the Pap test, i.e., the health services personnel (ORa = 0.02, 95% C.I. = 0.0008-0.05). CONCLUSIONS: The lack of use and the misuse of Pap smears vary importantly among the different social and reproductive factors. But the principal reasons for lack of use were not knowing about the Pap test and a low educational level. We propose a greater diffusion on the benefits of the test in the Mexican population, through massive means of communication and health services.     

Tricuspid valve endocarditis in a non-drug addict associated with peliosis hepatis

The aims of the present study were to investigate whether the tachykinins substance P and neurokinin A were present in gingival crevicular fluid in both periodontal health and disease and to study the relationship with periodontal inflammation. Gingival crevicular fluid (GCF) was collected from a healthy, a gingivitis and a periodontitis site in 20 subjects with periodontitis and from a healthy site in 20 subjects without periodontitis. The volume of GCF was measured and each sample subsequently analysed for substance P and neurokinin A by radioimmunoassay. There were significantly increased levels of substance P-like immunoreactivity (SP-LI) and neurokinin A-like immunoreactivity (NKA-LI) in gingivitis and periodontitis sites compared with healthy sites. Both tachykinins were significantly elevated in periodontitis affected subjects, with significantly more tachykinin-like immunoreactivity at healthy sites in periodontitis affected compared with periodontally-healthy subjects. Despite the considerable individual variation in the levels of SP-LI and NKA-LI, both tachykinins were present at levels at which they could have biological activity. It is concluded that substance P and neurokinin A may have a r?le in the pathogenesis of periodontal disease and that further investigations could prove useful in clarifying the mechanisms through which neuropeptides could modulate periodontal health and disease.     

Vibrational Spectra of Ca3SiO5: Ultraviolet Laser Raman Spectroscopy at High Temperatures

The Raman spectra of Ca₃SiO₅ have been successfully obtained at temperatures up to 1353 K by a continuous-wave ultraviolet Raman spectroscopic system. The Raman spectra do not change significantly with an increase in temperature, despite triclinic ( T )→monoclinic ( M )→rhombohedral ( R ) transitions. The present result is described in terms of the parameter related to temperature variation at constant pressure, defined in a manner similar to the Gruneisen parameter. Raman bands located above 350 cm⁻¹ show smaller values of the parameter than lower frequency modes, suggesting that these higher frequency modes are assigned to SiO₄ internal modes.     

Cellular characterization of the 91kDa-ectopic ascitic antigen sharing antigenicity with MRP8 in the human placenta as revealed by immunoelectron microscopical colloidal-gold techniques

Cellular characterization of the 91kDa-ectopic ascitic protein that exhibits pregnancy-associated and tumour-related dynamics has been examined in the human placenta using an electron microscopic immunocolloidal-gold technique. This protein was initially isolated from the ascitic fluids of a patient suffered from ovarian and uterine cancers with mixed mesodermal tumours, and determined to be sharing antigenicity with the 28kDa-oncodevelopmental protein and a calcium-binding protein; MRP8/CFA, respectively. Placentas obtained were divided into three groups by their gestational periods. Small chorionic villous tissues were embedded in Lowicryl K4M resin or Epon 812 resin. Specific and higher labelings by gold-particles were obtained in sections of Lowicryl resin and, then, recognized in mesenchyme-derived cells and/or myeloid lineages; such as placental tissue macrophages (Hofbauer cells), fibroblasts, foetal myelomonocytic cells including endothelial cells, etc., in the first and second trimesters. So far, the pattern of antigenic appearances changed depending on the stage of gestation. On the other hand, 91kDa-protein was also determined in the syncytiotrophoblast, but not in cytotrophoblasts at whenever been examined. It is assumed that the antigenic expression in syncytiotrophoblasts might be reflected to be absorbed or incorporated from those of foetal or maternal origins, and the antibody used in this study should be sensitive to the antigenic epitope derived from those of myeloid lineages. In the light of these results, hypotheses concerning mechanisms of both transplacental permeability of substances by the placental barrier and cell/tissue differentiation by calcium-binding (and/or -depending) proteins such as 91kDa-protein, MRP8, etc.; presumable the S-100 protein family, are discussed further.     

Allergen specificity of skin-infiltrating T cells is not restricted to a type-2 cytokine pattern in chronic skin lesions of atopic dermatitis

The majority of allergen-specific T cells derived from inhalant allergen patch test lesions in patients with atopic dermatitis were previously found to produce a restricted type-2 cytokine pattern. Recent studies, however, have revealed that in chronic eczematous skin lesions of patients with atopic dermatitis, expression of the type-1 cytokine interferon-gamma predominates. To evaluate cytokine production by allergen-specific T cells in chronic atopic dermatitis, we established house dust mite (Dermatophagoides pteronyssinus)-specific T-cell clones from the dermis of chronic skin lesions of sensitized adult patients with atopic dermatitis. Frequencies of skin-derived T cells proliferating in the presence of Dermatophagoides pteronyssinus were between one in 138 and one in 4255, indicating that only a minority of skin-infiltrating T cells are allergen specific. When these cells were analyzed for their capacity to produce interferon-gamma, the majority (71%) of these cells were found to express interferon-gamma mRNA and to secrete interferon-gamma protein, either alone or in combination with interleukin-4. Phenotypic analysis revealed that 15% of skin-infiltrating allergen-specific T cells were CD8+. No selection of Vbeta elements was detected in Dermatophagoides pteronyssinus-specific T-cell clones. These studies demonstrate that allergen specificity of skin-infiltrating T cells is not restricted to a type-2 cytokine pattern in lesional atopic dermatitis. The notion that the majority of allergen-specific, skin-infiltrating T cells are capable of producing interferon-gamma further supports the concept that interferon-gamma expression has major pathogenetic relevance for the chronic phase of atopic dermatitis.