Occurrence of Yersinia enterocolitica, particularly serovar 03, biovar 4 in pork and beef

The paper deals with the incidence of Yersiniae in pork and beef, focused in particular on the prevalence of Yersinia enterocolitica, serovar 3, biovar 4. The author uses for detection the method of cold shock, alkalization of the sample, taking advantage of the tolerance of Yersinias of diluted alkalis and suppressing the contaminating microflora, and the the selective medium CIN agar with a locally manufactured supplement. Cultivation was either direct or after propagation in phosphate buffer pH 7.6. The authors isolated 84 strains of Yersinias, i.e. 60% of the total number of examined specimens. Four strains were Yersinia enterocolitica, serovar 03, biovar 4 from pork by direct cultivation. Twenty strains did not agglutinate with commercial serum O-Yersinia IMUNA; they were included in the group "Yersinia enterocolitica other biovars" and 60 strains were "Environmental Yersinia isolates". The author proved a seasonal incidence of Yersinie enterocolitica, serovar 03, biovar 4. The applied method of detection and the the selective medium CIN agar with supplement proved suitable. It is important to respect hygienic provisions during processing in the slaughterhouse with regard to the high incidence of environmental Yersinias and the possible incidence of pathogenic serovars of Yersinias.     

Oral leukoplakia. Current concepts and analysis of the term in the Spanish language

The purpose of this paper is to carry out an analysis of the term leukoplakia since its introduction in 1877 and to expose the most accepted concepts and present classification within specialists. For this purpose attention will be paid to definitions established in the international seminary developed in Malm? City, Sweden, in June 1983. A group of observations on present status of research and diagnostic methods and its limitations to pre-establish when a lesion of this type is going to evolve toward malignancy, is included. An important part of this paper is devoted to the linguistic analysis of leukoplakia and leukoplasia expressions. An extensive argumentation demonstrating the systematic impropriety in the Spanish Language of translating the English term "leukoplakia as leukoplasia, is presented. There is in Spanish the accurate translation, given by the expression leukoplakia, which is not only the adequate one for the exactness of its translation but also the one more conceptually adjusted to contemporary definition universally accepted, that is to say, a white plaque. Finally, a comment on importance of incorporates to our language the exact translation of scientific words, not only to fit it to present science, but also to a better fulfillment of its function in allowing the communication within Latin American researches themselves and with the world scientific community, is exposed.     

Comparison of the chelating capacity of EDTA and EGTA, a new demineralized agent, on molars in vitro

Recent morphologic studies have shown qualitative, how demineralizing substances clean teeth roots. In this work we attempt to describe quantitatively the "chelation process" and pH evolution of the quelator solution in-vitro inside the teeth during the reaction. These results indicate that Ca++ coming from hydroxyapatite release protons from EDTAH under neutral conditions. This is the most likely mechanism of the "self-limitation". Furthermore, it allow us to explain why EDTA Im and EGTA Im were more efficient than EDTA Na and EGTA Na upon demineralizing the tooth. EGTA Im turn out to be the fastest demineralizing agent as compared to EDTA Na which is currently employed in endodontic therapy.     

Follow-up of outpatients with essential hypertension. A comparison of three methods of blood pressure measurement.

Compared with conventional, routine blood pressure measurement in the outpatient department of a hospital, 24-hour blood pressure monitoring provides more comprehensive information about blood pressure values in day-to-day life of the hypertensive patient. The hospital setting with all its stimuli affects the hypertensive patients so that their values will be statistically significantly higher compared with normal ones. Recent years have seen the introduction into clinical practice of self-monitoring by the patients themselves. Comparison of these three methods for blood pressure measurements revealed that self-monitoring may provide fairly accurate values comparable with those obtained by the "standard method", i.e., 24-hour monitoring. In view of the low variability of the mean value of blood pressure over a period of several days, self-monitoring can be employed in groups of selected outpatients on long-term follow-up.     

Fusion-induced malignancy? A preliminary study. (a challenge to today's common wisdom).

Five fusions between mouse embryonic cells and syngeneic adult peritoneal macrophages were performed. The resulting hybrids as well as both parental cells (6 cultures of embryonal cells and 6 cultures of adult macrophages) were grown in vitro under the same culture conditions. All populations of explanted macrophages died during the second month in primary culture and five populations of cultured embryonic cells were lost within six months under in vitro conditions as well. One embryonic cell line survived and acquired transformed and/or malignant phenotype: When inoculated into either newborn or adult syngeneic mice, progressive growth of tumors with 100% take (6/6), histologically classified as poorly differentiated fibrosarcoma with areas of metaplastic bone and osteoid, was observed. Two out of five wild hybrid strains died within six months of cell culture. The resulting three hybrid cultures adapted themselves to in vitro conditions and finally permanent lines were established with all features of transformed phenotype in vitro and with the capacity to grow as undifferentiated fibrosarcomas with 100% take (6/6) when inoculated into syngeneic mice either s.c. or i.p. Cytogenetic studies were performed and phenotypic characteristics of these lines were explored as well. Biological assays performed for the presence of oncogenic viruses were negative and none of the malignant cell lines showed positive staining with the monoclonal antibody specific for large T-antigen. It is suggested that cell fusion of two normal partners may switch on the cascade of abnormal processes which may culminate in neoplastic conversion. Cell fusion might play also a significant role in the so called "spontaneous" transformation.     

Superior mesenteric artery is more important than inferior mesenteric artery in maintaining colonic mucosal perfusion and integrity in rats

Mucosal hemodynamics (by reflectance spectrophotometry) and mucosal damage (by histologic examination) following acute colonic ischemia were evaluated in different anatomic locations in the colon of anesthetized rats. The reflectance spectrophotometer provides an index of mucosal hemoglobin concentration (IHB) and an index of oxygen saturation of hemoglobin (ISO₂). The patterns of ischemia without congestion (IHB, ISO₂) during superior mesenteric artery occlusion, and ischemia with congestion (IHB, ISO₂) during portal vein occlusion, previously demonstrated in the stomach and duodenum, are also applicable to the colon. The significant linear correlations between changes (as percent of baseline) in IHB, ISO₂, and hydrogen gas clearance suggest that changes in these indices are adequate indicators of changes in colonic mucosal perfusion. Superior mesenteric artery ligation produced significant reductions in both indices, and an increase in damage in the mucosa of the cecum, transverse colon, splenic flexure, and left colon, but not the rectum. Inferior mesenteric artery ligation produced only slight reduction in these indices and minimal damage only in the mucosa of the splenic flexure. These results support the hypothesis that the superior mesenteric artery is more important than the inferior mesenteric artery in maintaining colonic perfusion and colonic mucosal integrity in the rat.Supported by the American Society for Gastrointestinal Endoscopy Career Development Award (H850208, H870212), Veterans Administration Medical Research Funds; and in part by research grants (0162-01, 0162-02; 0291-01) from the Smokeless Tobacco Research Council, Inc.; and by funds provided by the Cigarette and Tobacco Surtax Fund of the State of California through the Tobacco Related Disease Research Program of the University of California.     

Depressed adjuvant arthritis in chronically Trypanosoma cruzi infected rats: reversal by cyclophosphamide.

Chronically Trypanosoma cruzi infected "I" rats and syngeneic naive recipients, transferred with a T cell enriched spleen cell population from infected donors, develop an attenuated arthritis when challenged with complete Freund's adjuvant. We report that cyclophosphamide, 40 mg/kg body weight, given 48 h before induction, was able to reestablish or exacerbate adjuvant arthritis in infected and control rats, respectively. Although the T cell enriched spleen cells from infected donors continued to down regulate adjuvant arthritis in syngeneic recipients given cyclophosphamide 48 h before cell transfer, treatment of infected donors with cyclophosphamide, 48 h before cell collection, prevented these cells from exerting such effect when transferred to healthy recipients receiving no cyclophosphamide. It is suggested that cyclophosphamide may primarily affect a suppressor cell population, present in the infected host, with regulatory activity on adjuvant arthritis.     

Late results after repair of partial atrioventricular septal defect in adolescents and adults

From January 1966 through December 1985, 29 adolescents and adults underwent surgical repair of a partial atrioventricular septal defect at our institution. The patients included 20 females and 9 males, whose ages ranged from 16 to 47 years (mean, 27.6 +/- 10.1 years). Preoperatively, 24 patients were in New York Heart Association functional class I or II, and 5 were in class III. The pulmonary artery systolic pressure ranged from 22 to 62 mmHg (mean, 38.3 +/- 12.7 mmHg). The pulmonary-to-systemic flow ratio ranged from 1.4 to 2.9 (mean, 2.3 +/- 0.5). Upon left ventriculography, regurgitation through the left atrioventricular valve was trivial or nonexistent in 4 patients (13.8%), mild in 14 (48.3%), moderate in 10 (34.5%), and severe in 1 patient (3.4%). All patients underwent patch closure of the ostium primum defect, and all but 2 underwent partial or complete suturing of the septal commissure. One patient died within 30 days, for a hospital mortality of 3.4%. The follow-up period ranged from 7 to 25 years (mean, 15.2 +/- 5.3 years). Postoperatively, all patients were evaluated with 2-dimensional and Doppler echocardiography. One patient underwent early implantation of a permanent pacemaker for persistent complete heart block. Three patients succumbed to late death 10, 15, and 21 years after operation. Among the 25 long-term survivors, 1 patient required late valve replacement because of severe left atrioventricular valve regurgitation. Nine (37.5%) of the other 24 long-term survivors had little or no regurgitation. Of the 11 patients with moderate-to-severe preoperative left atrioventricular valve regurgitation, 4 had moderate postoperative regurgitation. Seventeen patients had a moderate or severe persistent apical systolic murmur. At the latest follow-up in 1991, 5 (20%) of the 25 long-term survivors had significant arrhythmias. At 25 years, the actuarial survival rate was 78.9% +/- 25.6%. All 25 surviving patients were in New York Heart Association class I or II. The rate of freedom from reoperation was 77.7% +/- 25.9%. We conclude that, in adolescents and adults, correction of a partial atrioventricular septal defect entails little risk and is likely to improve the patient's functional status. Repair of the left atrioventricular valve yields good results, even at long-term follow-up.     

Hemorheological alterations in mild essential hypertension.

Blood rheological properties were studied in 21 patients suffering from essential hypertension (EHT), degree I-II according to WHO criteria. These patients were diagnosed "de novo". The whole blood filterability (WBF), blood viscosity (BV) at 230 s-1 and 23 s-1, red cell deformability (FI), erythrocyte aggregation in autologous (MEA) and normal plasma (MEAc), fibrinogen (Fbg) and hematocrit (Ht) have been evaluated. In the hypertensive patients we have found decreased WBF, greater BV and FI in comparison with the control group (p less than 0.001). Likewise, MEA and Fbg were increased, though the differences were less significant (p less than 0.01). The evaluation of Ht did not show any differences between the two groups. The results suggest that in the newly diagnosed EHT, clear hemorheological alterations occur, both in plasma and in the erythrocytes, which could play a role in the pathogenesis of the aforementioned disease.     

Coronary sinus thrombosis in patients after heart transplantation

Two cases of coronary sinus thrombosis with myocardial changes suggestive of "haemorrhagic infarsation" as the cause of death of cardiac transplantant recipients are presented. The discussion points to the macroscopical and histologic findings completely different from those seen in myocardial infarction induced by coronary artery occlusion.