Protection of mice against gastric colonization by Helicobacter pylori by single oral dose immunization with attenuated Salmonella typhimurium producing urease subunits A and B

Helicobacter pylori is a Gram-negative bacterial pathogen associated with gastritis, peptic ulceration, and gastric carcinoma. The bacteria express a strong urease activity which is known to be essential for colonization of gnotobiotic pigs and nude mice. UreA and UreB, two structural subunits of the active enzyme, were expressed in the attenuated Salmonella typhimurium live vaccine SL3261 strain. Evaluation of protection against H. pylori was performed in Balb/c mice by oral immunization with a single dose of the vaccine strain. Five weeks after immunization, mice were challenged orally three times with a mouse-adapted H. pylori wild type strain and, six weeks later, mice were sacrificed to determine H. pylori infection by detection of urease activity from the antral region of the mouse stomachs. In several independent experiments, we observed 100% infection with H. pylori in the non-immunized mice and no infection (100% protection) in the mice immunized with S. typhimurium expressing recombinant UreA and UreB. Specific humoral and mucosal antibody responses against UreA and UreB were observed in mice immunized as indicated by western blots and ELISA assays. These data shows that oral immunization of mice with urease subunits delivered by an attenuated Salmonella strain induced a specific immune response and protected mice against H. pylori colonization. Single oral dose immunization with UreA and UreB delivered by a live Salmonella vaccine vector appears to be an attractive candidate for human vaccination against H. pylori infection. In addition, this model will aid to elucidate the effective protection mechanisms against H. pylori in the gastric mucosa.     

Effect of para-aminobenzoic acid on the development of rat embryos when applied to pregnant females

BACKGROUND: Epicardial pacing wires are routinely used for the diagnosis and treatment of bradyarrhythmias after cardiac surgery. The frequency of arrhythmias during removal of the wires is unknown, and methods of removal vary among institutions. OBJECTIVES: To describe the frequency of ventricular arrhythmias during removal of epicardial pacing wires from the right ventricle, to determine variables that are predictive of ventricular arrhythmias during wire removal, and to describe patients' perceptions of wire removal. METHODS: A convenience sample of 145 patients who had undergone cardiac surgery was studied during the course of 1 year. Electrocardiographic and vital signs were recorded throughout wire removal. Patients' records were reviewed for variables that could predict the occurrence of arrhythmias during wire removal: laboratory values, history of arrhythmias, medications, medical history, postoperative course, and pain reported by the patient. RESULTS: Sixty-six percent of patients had one premature ventricular contraction or more while the ventricular wires were being removed. Seven percent of patients had nonsustained ventricular tachycardia during wire removal. Patients who had repeat cardiac surgery had significantly more nonsustained ventricular tachycardia than did all other patients (P < .01). Only a history of heart failure (P < .02) was a significant predictor of premature ventricular contractions during wire removal. On a scale of 0 (no pain) to 10 (worst pain), the mean rating of pain intensity reported by patients was 2.39 (SD = 2.77). CONCLUSION: Patients may be at risk for ventricular arrhythmias during removal of epicardial pacing wires. Findings support the need for electrocardiographic monitoring while pacing wires are being removed.     

Androstenedione conversion in human peripheral blood lymphocytes

Indigenous Indian groups comprise approximately 20% of Ecuador's population, the third largest percentage in all of Central or South America, yet immunogenetic data on these groups are lacking in the literature. In the course of population migration studies, sera collected from 65 Ecuadorians living in the northern province of Esmeraldas were typed for six GM and two KM markers. The study population consisted of 47 Cayapa Indians and 18 blacks of African origin, descendants of slaves imported into the area during the seventeenth century. The Cayapa demonstrated three GM phenotypes, two of which are common to other South American Indian tribes. The frequency of KM1 positive Cayapa Indians (63%) is similar to other South American Indian tribes, but is significantly greater than the Huaorani of eastern Ecuador (2%), the only other Ecuadorian Indian group for whom limited immunoglobulin allotype data are available (chi 2 = 35.8, P < 0.0001).     

The use of streptokinase preparations in pleural empyema and pyopneumothorax

Prevailing fibrin-formation in the pleural cavity entails hypoactivity of trypsin-like proteinases and a high inhibitory potential in the serum and pleural exudate. Streptokinase preparations appeared an effective means of pharmacological pulmonary decortication in patients with high pleural levels of plasminogen. The authors obtained higher efficacy of conservative therapy for pyothorax when they used a specially designed technique of intrapleural administration of streptokinase-activated fresh frozen plasma of the same group. The outcomes of the disease were also improved noticeably.     

The participation of the genetic apparatus in the mechanisms of memory trace formation: the role of the calcium-regulatory system of the neurons in rats

Historically, formalin fixed (FF) tissues could not be used as a source of DNA in forensic science due to the fact that the DNA was too degraded for DNA analysis. With the introduction of the polymerase chain reaction (PCR) technique to forensic science, the usefulness of DNA from this biological material has been re-evaluated. This study evaluates the potential use of DNA from FF and formalin fixed paraffin embedded (FFPE) tissues in 13 PCR systems; HLA DQ alpha, LDLR, GYPA, HBGG, D7S8, GC, D1S80, vWA31, THO1, F13A1, FES/FPS, TPOX, and CSF1PO. The first six, HLA DQ alpha, LDLR, GYPA, HBGG, D7S8, and GC are reverse dot blot systems, D1S80 is an amplified fragment length polymorphism (AmpFlp) system and the others are short tandem repeats (STRs). This study shows that FFPE tissue which has not been fixed in formalin for more than three days is a useful source of DNA for 12 of the 13 PCR systems. In contrast, FF tissue did not prove to be a reliable source of DNA for the PCR techniques examined here.     

Characteristics and mechanisms of the interhemisphere synchronization in the rat motor cortex

Synchronised activity of the callosal cells was studied in the rat motor cortex. Cross-correlation analysis revealed narrow symmetrical peaks (less than 20 ms) and intermediate ones (30-80 ms). Common neuron(s) located in one hemisphere reciprocally connected callosal cells can play the role of a "common input" that synchronises discharges of the cells in both hemispheres. The narrow and intermediate peaks seem to be mediated by mono- and polysynaptic connections, resp.     

Cardiac function in total anomalous pulmonary venous return before and after surgery

Cardiac performance was evaluated in 12 infants with isolated total anomalous pulmonary venous return. Four had significant pulmonary venous obstruction and severe pulmonary hypertension (group A). Eight had no obvious venous obstruction, and the pulmonary pressures were lower (group B). In all subjects, right ventricular end-diastolic volume was increased (197% of predicted normal) and its ejection fraction was normal. Left ventricular volume was, generally speaking, still in the normal range (87% of predicted normal); however, its ejection fraction was reduced (0.57 vs normal of 0.73) and left ventricular output was low (3.08 L/min/m2 vs normal of 3.98). Left atrial volume was consistently small (53% of predicted normal) with an appendage of normal size. The infants in group A had smaller chamber volumes/m2 BSA than those in group B. Left atrial function was abnormal, characterized by reduced reservoir function and a greater role as "conduit" from right atrium to left ventricle. Left atrial size was not found to be critical in the surgical repair of TAPVR. Cardiac function is restored to normal following surgery.