Malignant teratoma of the thyroid: case report.

Teratomas in the neck are rare neoplasms. Most of them occur in infants less than 1 year and are benign. In contrast, thyroid teratomas in adults are malignant and have fatal outcomes because of spread of tumor refractory to treatment. We report a case of a primary thyroid malignant teratoma in a 37-year-old woman. She was treated successfully with a combination of surgery, postoperative cis-platinum-based chemotherapy, and radiation therapy to the neck. Although the time of follow-up is short (24 months), we attribute her successful outcome to the use of this intensive therapeutic approach.     

Air seepage from endotracheal tube cuffs during anesthetic procedures. How to solve this problem without changing tubes? An experimental model using human tracheas]

OBJECTIVES: To demonstrate by an experimental model that a continuous medicinal airflow system giving a pressure of 30 cmH2O effectively stops leakage from endotracheal tubes. MATERIAL AND METHODS: Ten tracheas with their main bronchi were removed from cadavers with no pulmonary disease. The tracheas were placed vertically and tubes previously perforated with increasing caliber needles were inserted and connected to a continuous flow system. The flow of medicinal air generated in the cuff was monitored with a flow meter and pressure was measured with a manometer. When a pressure of 30 cmH2O was reached, the trachea was filled with saline. We then observed the moment at which, when pressure fell, the saline began to leak from the bronchi. The levels observed were expressed as arithmetic means and standard deviations. RESULTS: No leakage was observed when the flow produced pressures above 10 cmH2O for 25 G caliber holes, above 15 cmH2O for 24 G holes, or above 20 cmH2O for 25 G, 21 G, 20 G, 18 G or 16 G holes. For 14 G holes, a flow producing pressures over 25 cmH2O were needed. Pressure up to 80 cmH2O was required to stop leakage from a scalpel cut. CONCLUSIONS: We found that adjusting flow and pressure is a valid way to stop leakage from small holes. The method does not control leakage from large holes or cuts.     

A novel assessment of the quality of immunohistostaining overcomes the limitations of current methods

Quality assurance has become an integral part of surgical pathology. Despite the development of interdisciplinary quality systems, however, the means for objective analysis in surgical pathology are limited. Immunohistostaining is a multi-factorial procedure that depends on the quality of reagents and antibodies employed in the process and on technical methodology. In the present study, we aim to establish a straightforward procedure for objective quality evaluation of the components involved in immunohistostaining. The quality of two of these components, the primary antibody and the automated staining device, was assessed by employing each component from two different sources, one serving as the test substance and the second as the reference. Assessment was performed by at least two pathologists in a blinded fashion using pre-established quality criteria and scores. The quality analysis of two automated devices revealed a significant difference between the reference and tested devices (3.5+/-1.7 and 4.2+/-1.5, respectively, P>0.05), while the analysis of two selected antibodies did not reveal any statistical difference. The described method provided objective quality assessment of selected components affecting immunohistostaining by elaborating numeric values that enabled statistical analysis. This approach is applicable to any given component in various surgical pathology procedures.     

Epitopes of human fibrin recognized by the rheumatoid arthritis-specific autoantibodies to citrullinated proteins

Formation of the epitopes recognized by the rheumatoid arthritis (RA)-specific autoantibodies to citrullinated proteins (ACPA) on filaggrin and on the alpha- and beta-chains of fibrin, their synovial target, requires conversion of their arginyl residues into citrullyl residues, but is also affected by their amino-acyl environment. Using competition with five citrullinated filaggrin-derived peptides bearing major ACPA epitopes, we confirmed the close cross-reactivity between filaggrin and citrullinated fibrin. To identify the sequential epitopes recognized on fibrin by ACPA, 71 citrullinated 15-mer peptides derived from all the sites of the alpha- and beta-chains of fibrin harboring arginyl residues were tested by ELISA using ACPA-positive RA sera exhibiting different reactivity profiles to the five filaggrin peptides. We identified 18 fibrin-derived peptides bearing ACPA epitopes. Regarding the ability of fibrinogen arginyl residues to be citrullinated in vitro, 11 of the peptides likely correspond to in vivo targeted epitopes. Two out of them bear major epitopes and are located in the central globular domain of the protein. In the synovial tissue, fibrin citrullination and ACPA binding could impair fibrin degradation by plasmin. The immunological conflict between ACPA and fibrin could therefore sustain synovial inflammation not only via pro-inflammatory effector mechanisms but also via impairment of fibrinolysis.     

Cohesin component dynamics during meiotic prophase I in mammalian oocytes

Cohesins are chromosomal proteins that form complexes involved in the maintenance of sister chromatid cohesion during division of somatic and germ cells. Three meiosis-specific cohesin subunits have been reported in mammals, REC8, STAG3 and SMC1 beta; their expression in mouse spermatocytes has also been described. Here we studied the localization of different meiotic and mitotic cohesin components during prophase I in human and murine female germ cells. In normal and atretic human fetal oocytes, from leptotene to diplotene stages, REC8 and STAG3 colocalize in fibers. In murine oocytes, SMC1beta, SMC3 and STAG3 are localized along fibers that correspond first to the chromosome axis and then to the synaptonemal complex in pachytene. Mitotic cohesin subunit RAD21 is also found in fibers that decorate the SC during prophase I in mouse oocytes, suggesting a role for this cohesin in mammalian sister chromatid cohesion in female meiosis. We observed that, unlike human oocytes, murine synaptonemal complex protein SYCP3 localizes to nucleoli throughout prophase I stages, and centromeres cluster in discrete locations from leptotene to dictyate. At difference from meiosis in male mice, the cohesin axis is progressively lost during the first week after birth in females with a parallel destruction of the axial elements at dictyate arrest, demonstrating sexual dimorphism in sister chromatid cohesion in meiosis.     

Trypanosoma cruzi antigen that interacts with the beta1-adrenergic receptor and modifies myocardial contractile activity

Previously, we have demonstrated that plasma membranes from the parasite Trypanosoma cruzi (T. cruzi) recognize and adhere to host cells through parasite surface attachment molecules that have affinity for beta(1)-adrenergic receptors (beta(1)-ARs) on target organs. In this report we identify a parasite protein that not only interacts with beta(1)-ARs, but also displays beta-agonist-like activity. We demonstrate that a recombinant maltose binding protein fusion of Tc13 Tul (MBP-Tc13 Tul), a member of the T. cruzi antigen 13 family of surface antigen proteins, competes for binding sites with the beta-adrenergic receptor antagonist [125I]-CYP on membranes purified both from CHO cells expressing human beta(1)-ARs and from rat atria. The competition is prevented by pre-treating MBP-Tc13 Tul with antibodies directed against the EPKSA repeat domain of Tc13 Tul, implicating this portion of the molecule in binding to the beta(1)-AR. Furthermore, MBP-Tc13 Tul activates rat myocardial beta(1)-ARs, resulting in synthesis of cyclic adenosine monophosphate (cAMP) and an increase in cardiac contractility. These biological effects are selectively suppressed by the beta(1)-AR antagonist atenolol, by a synthetic peptide corresponding to the second extracellular loop of the human beta(1)-AR, and by the anti-EPKSA repeat antibodies. These results imply that the Tc13 Tul cell-surface antigen of T. cruzi plays a central role in misregulating the beta(1)-AR following parasite infection, and may be a causative factor of dysautonomic syndrome described in Chagas' disease.     

Analysis of some phenotypic traits of feces-borne temperate lambdoid bacteriophages from different immunity groups: a high incidence of cor+, FhuA-dependent phages

A group of previously isolated heterogeneous mEp lambdoid phages (43) from 19 different immunity groups for phage infection was further characterized to gain insight into some phenotypic traits and to assess their relationship with phage lambda. Interestingly, the FhuA host receptor was required by the majority of mEp phages (37 out of 43; approximately 85%). The cor gene, which has been reported to be involved in FhuA-dependent exclusion of lambdoid phages, was also found in most of the FhuA-dependent phages. Accordingly, no cor amplification by PCR was obtained among the six FhuA-independent mEp lambdoid phages. In contrast, it was found that around 25% of the population (10 out of 43 phages) required the specific and essential lambda N antitermination function, and the lambda site-specific DNA recombination function was observed only in two members (4.6%). Thus, a larger proportion of phages require the FhuA receptor for infection, and this is frequently correlated with the cor gene.     

Beta-adrenergic effect of antibodies from chagasic patients and normal human lymphocytes on isolated rat atria

It was previously shown that fresh sera from chagasic patients that contained antibodies reacting with the plasma membrane of striated muscle and endothelial cells (EVI(+) serum) could act in co-operation with complement as a partial beta-agonist increasing the frequency of contraction of isolated rat atria. This activity was absent in EVI(-) chagasic serum or normal human serum and was lost upon heat-inactivation of EVI(+) serum. Also, IgG purified from EVI(+) serum was virtually devoid of activity. In this report we demonstrate that normal human lymphocytes can collaborate with EVI(+) IgG or heat-inactivated EVI(+) sera and induce both positive ino- and chronotropic effects on isolated rat atria. Depletion of phagocytic mononuclear cells from the effector cell population did not alter its activity, whereas blockade of the receptors for the Fc fragment of IgG with heat-aggregated IgG abrogated the effect. After fractionation of the T and non-T cell populations by sedimentation of E rosette forming cells the activity was present in the non-T cell fraction. The mechanism triggered involved a beta-adrenergic reaction that could be blocked by 10^-7 M (-)-propanolol and not by inhibitors of prostaglandin synthesis (10^-6 M indomethacin and 1·8 × 10^-4 M acetyl salicylic acid) or an anti-histamine drug (10^-6 M pyrilamine). Since positive EVI reactivity and myocardial lympho-mononuclear cell infiltrates are frequent in patients with chronic Chagas' cardiomyo-pathy, the possibility that they could interact influencing the rhythm and contractile activity of the heart should be taken into account.