Gastrointestinal disorders in Down syndrome

Down syndrome is the most common human chromosomal disorder. Among clinical findings, one constant concern is the high prevalence of gastrointestinal system alterations. The aim of this study was to determine the prevalence of gastrointestinal disorders at a Down syndrome outpatient clinic during a 10‐year follow‐up period. Data from medical files were retrospectively reviewed from 1,207 patients. Gastrointestinal changes occurred in 612 (50.7%). The most prevalent disorder was chronic intestinal constipation. Intestinal parasite occurred in 22% (mainly giardiasis), gastroesophageal reflux disease in 14%, digestive tract malformations occurred in 5%: 13 cases of duodenal atresia, 8 of imperforate anus, 4 annular pancreases, 2 congenital megacolon, 2 esophageal atresias, 2 esophageal compression by anomalous subclavian and 1 case of duodenal membrane. We had 38/1,207 (3.1%) patients with difficulty in sucking and only three with dysphagia that resolved before the second year of life. Peptic ulcer disease, celiac disease, and biliary lithiasis were less prevalent with 3% each. Awareness of the high prevalence of gastrointestinal disorders promotes outstanding clinical follow‐up as well as adequate development and greater quality of life for patients with Down syndrome and their families.     

Sputum induction as a research tool for the study of human respiratory mucus

The study objectives were to compare in vitro transportability and physical properties of respiratory mucus, obtained invasively by direct collection (DC) right after endotracheal intubation and non-invasively by sputum induction with 3% hypertonic saline solution inhalation (SI) 24 h before the anesthesia. Twenty-two patients with no pulmonary disease scheduled for elective abdominal surgical procedures were studied. The parameters analyzed and the main results are as follows. (1) Transportability by cilia (MCT), SI was higher than DC (0.94+/-0.25 and 0.62+/-0.25; P<0.001). There was a significant correlation between the two methods and DC could be estimated by: DC=0.21+(0.44 SI) (r=0.44; P<0.001). (2) Transportability by cough (CC), SI was higher than DC (68.23+/-32.1 and 33.58+/-19.04 mm; P=0.002). (3) Contact angle (CA), SI was lower than DC (10+/-3 degrees and 22+/-14 degrees ; P=0.025). (4) Rheological properties (no significant difference obtained between SI and DC). These results indicated that SI changes mucus physical properties and transportability in non-expectorators.     

Experimental vitrification of human compacted morulae and early blastocysts using fine diameter plastic micropipettes

BACKGROUND: Vitrification of human blastocysts has been successfully applied using grids, straws and cryoloops. We assessed the survival rate of human compacted morulae and early blastocysts vitrified in pipette tips with a smaller inner diameter and solution volume than the previously described open pulled straw (OPS) method. METHODS: Excess day 5 human embryos (n = 63) were experimentally vitrified in vessels. Embryos were incubated at 37 degrees C with sperm preparation medium (SPM) for 1 min, SPM + 7.5% ethylene glycol (EG)/dimethylsulphoxide (DMSO) for 3 min, and SPM + 16.5% EG + 16.5% DMSO + 0.67 mol/l sucrose for 25 s. They were then aspirated (0.5 microl) into a plastic micropipette tip (0.36 mm inner diameter), exposed to liquid nitrogen (LN(2)) vapour for 2 min before being placed into a pre-cooled cryotube, which was then closed and plunged into LN(2). Embryos were warmed and diluted using 0.33 mol/l and 0.2 mol/l sucrose. RESULTS: The survival rate for compacted morulae was 73% (22/30) and 82% (27/33) for early blastocysts. CONCLUSIONS: The survival rates of human compacted morulae and early blastocysts after vitrification with this simple technique are similar to those reported in the literature achieved by slow cooling and other vitrification protocols.     

Presence of argyrophilic cytoplasmic and nuclear proteins in the spermatic cells of Nucella lapillus (Gastropoda, Prosobranchia)

The technique for ultrastructural localization of argyrophilic proteins was modified and NOR-Silver staining methods were applied to the study of the distribution of these proteins in the spermatic cells of Nucella lapillus (Gastropoda, Prosobranchia). Two types of selective silver deposits were found during the different phases of spermiogenesis and in mature spermatozoa. Argyrophilic nuclear, nucleolar and cytoplasmic proteins were simultaneously detected by improvement of a modified one-step silver technique.     

Synaptonemal complex analysis in spermatocytes and oocytes of rainbow trout,Oncorhynchus mykiss (Pisces,Salmonidae): the process of autosome and sex chromosome synapsis

The surface-spreading synaptonemal complex (SC) technique was employed to analyze spermatocytes and oocytes of rainbow trout in order to visualize the process of autosome and sex chromosome synapsis in this species. The structure of lateral elements (LEs) of the SC and the chromosome synapsis process at the stages of leptotene, zygotene and pachytene are described. Comparative analysis of SCs of spermatocytes and oocytes showed a difference in the synaptic process, i.e. in spermatocytes all LEs were synapsed before the appearance of centromeric regions in the biarmed elements, while in the oocytes some fully synapsed LEs, including the centromeric region of the biarmed elements, were found together with fully or partially unsynapsed LEs. In males the sex chromosome synapsis starts only after all autosomes have synapsed. Irregular synapses involving three or four LEs were found in 3.4% of the cells analyzed in mid or late zygotene. Multivalents were found in males and females. Some aspects of initial meiotic development and their implications in rainbow trout cytogenetics, genetics and evolution are discussed.     

Bulk immunopurification and development of a radioimmunoassay for human and murine F liver protein

By taking advantage of the cross-reaction for human F liver protein (F antigen) of a monoclonal antibody raised to mouse F antigen, human F antigen has been immunopurified in bulk. The molecular weight is 44 000. Using this material as a standard, affinity-purified polyclonal anti-F antibody on a solid phase and radiolabelled monoclonal anti-F antibody to detect bound protein, a capture immunoradiometric assay capable of detecting down to 1 ng X ml-1 of F antigen has been developed. Using this assay, the average level of F antigen in normal mouse serum (CBA strain) is 16 ng X ml-1 (360 pM) and in human serum 10 ng X ml-1 (250 pM).     

Accuracy of a commercial enzyme-linked immunosorbent assay for CagA in patients from Brazil with and without gastric carcinoma

We validated a commercial enzyme-linked immunosorbent assay for the detection of anti-CagA antibodies in Brazilian patients with Helicobacter pylori infection. The test presented high sensitivity (97.4%) and specificity (88.9%) when employed in patients without gastric carcinoma. However, in gastric carcinoma patients, the test was neither sensitive nor specific enough to detect cagA-positive H. pylori infection.     

Association between atopy and recurrent vaginal candidiasis

To determine whether there is an association between atopy and recurrent vaginal candidiasis (RVC) and to evaluate the type-2 immune response in patients with RVC. Evaluation of immediate hypersensitivity skin tests to aeroallergens, measurement of total IgE and Candida albicans specific IgE and levels of IL-5 in 44 women with RVC and 26 with sporadic vaginal candidiasis (SVC). Statistical analyses were performed by Mann-Whitney test and chi(2) test with Yates correction. History of atopy (68%) and positive skin test (42%) were higher (P < 0.05) in RVC than in patients with SVC. No significant difference was found in total IgE, C. albicans specific IgE and IL-5 levels. There was a strong association between atopy and RVC, but type-2 immune response to C. albicans antigen was absent or similar in the two groups of patients.     

Solubilization and immunological identification of presynaptic alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors in the rat hippocampus

Alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors have been identified mostly as postsynaptic receptors mediating fast glutamatergic synaptic transmission. However, neurochemical studies based on the modulation of neurotransmitter release have suggested the existence of presynaptic AMPA receptors. We have used a recently described technique that allows a high-purity fractionation of the pre- and postsynaptic proteins of synaptic junctions to evaluate the distribution of the different AMPA receptor subunits in rat hippocampal synapses. Surprisingly, we found very high levels of GluR1- and GluR2/3-like immunoreactivity in the presynaptic fraction, but also in the postsynaptic and extrasynaptic fractions. GluR4-like immunoreactivity was much less abundant but was still detected, predominantly in the postsynaptic fraction. This methodology appears to be far more sensitive than the classical immunogold electron microscopy to determine the localization of synaptic receptors.