[Cardiac surgery after liver transplantation]

An aortic valve replacement and an aorto-coronary bypass were done in a woman of 57 years old after an orthotopic liver transplantation. The surgical risk was increased by the antecedent liver transplantation, the immunosuppression, chronic renal insufficiency and antiphospholipid syndrome. Surgery and the post-operative period were not complicated. Cardiac surgery is not a contraindication for patients with a prior organ transplant. These individuals have a higher cardiovascular risk and require a cardiovascular follow-up the modalities of which are yet to be defined.

Macrolide resistance phenotypes in Streptococcus pneumoniae in Santiago, Chile

The mechanism of resistance was investigated in 39 macrolide-resistant clinical isolates of Streptococcus pneumoniae isolated from January 1997 to July 1999 in Santiago, Chile. Our results showed that 22 (56.5%) were macrolide-resistant, clindamycin-susceptible isolates (M phenotype) and 17 (43.5%) were macrolide and clindamycin resistant (MLS(B) phenotype). mefE gene was detected in all M phenotype, while ermB gene was detected in all MLS(B)-phenotype strains. Serotype 14 was the most frequent serotype among M-phenotype strains, and serotypes 19 and 23F were the most frequent serotypes in MLS(B) strains. These results demonstrate that both phenotypes of macrolide-resistant S. pneumoniae are found in Santiago, Chile, with the M phenotype predominating.

Monostotic fibrous dysplasia of the clivus: MRI and CT findings

Fibrous dysplasia is a developmental disorder caused by abnormal proliferation and maturation of fibroblasts resulting in replacement of mature bone by structurally weak, immature woven bone. Clival involvement in monostotic fibrous dysplasia is extremely unusual, and has rarely been reported previously. We report a case of monostotic fibrous dysplasia of the clivus with special emphasis on the imaging findings and differential diagnosis.

Molecular analysis of HLA-DRB1, DQA1, DQB1, DQ promoter polymorphism and extended class I/class II haplotypes in the Seri Indians from Northwest Mexico

The study of the genetics of the Major Histocompatibility Complex (MHC) in Amerindians is of great value in understanding the origins and migrations of these native groups, as well as the impact of immunogenetics on the epidemiology of diseases affecting these populations. We analyzed, using Polymerase Chain Reaction and Sequence Specific Oligonucleotide Probes (PCR-SSOP), DRB1, DQA1, DQB1 alleles and the promoter regions of DQA1 and DQB1 genes in 31 unrelated and 24 related Seri, a Mexican Indian group, from the state of Sonora (Northwest Mexico). The class II genotypes of this population were found to be in genetic equilibrium. The allele frequency (AF) of the prevalent DRB1 alleles were DRB1*0407 (48.4%), DRB1*0802 (33.9%) and DRB1*1402 (16.1%). The most frequent DQA1 and DQB1 alleles were DQA1*03011 (AF = 50.00%), DQA1*0401 (AF = 33.87%) and DQA1*0501 (AF = 16.13%); DQB1*0302 (AF = 50.00%), DQB1*0402 (33.87%) and DQB1*0301 (16.13%); which were in combination with DRB1*0407, DRB1*0802 and DRB1*1402, respectively. Three QAP and three QBP alleles were present (QAP 3.1, 4.1, 4.2; QBP 3.1, 3.21, 4.1) associated with the typical published DQA1 and DQB1 alleles. Four class II haplotypes were present in family members: DRB1*0407-QAP-3.1-DQA1*03011-QBP-3.21-DQB1*0302; DRB1*0802-QAP-4.2-DQA1*0401-QBP-4.1-DQB1*0402; DRB1*1402-QAP-4.1-DQA1*0501-QBP-3.1-DQB1*0301 and DRB1*0701-QAP-2.1-DQA1*0201-QBP-2.1-DQB1*0201. The family data were used to confirm extended haplotypes. A total of 21 haplotypes were found when A* and B* loci were also considered. The three most frequent combinations included A*0201-B*3501-DRB1*0407, A*3101-B*5101-DRB1*0802, and A*0201-B*40-DRB1*1402.

Distribution of TAP gene polymorphisms and extended MHC haplotypes in Mexican Mestizos and in Seri Indians from northwest Mexico

The study of the genetic structure is very useful for investigating the biological significance of polymorphism and may provide clues to understand population origins. We present TAP1/TAP2 gene analysis in the Seri indians from Sonora, and in Mestizos from the highlands of Mexico. Thirty-two Seri and 89 Mestizos were studied. TAP genes were typed using the ARMS-PCR technique. The most frequent alleles in Seri were: TAP1*0101/02, (68.8%); TAP1*02011/02012, (31.2%); TAP2*0201, (38.7%) and TAP2*0101, (29.0%). TAP1*0301, TAP1*0401, TAP2*0102 TAP2*0103 and TAP2H were absent in them. For Mestizos, the prevalent alleles were: TAP1*0101/02 (75.8%); TAP1*02011/12 (20.3%); TAP2*0101 (45.4%) and TAP2*0201 (29.3%). These results are similar to those found in Kaingang and Caucasians from Brazil, four Mediterranean, other Caucasians, two Oriental and one African group. In Seri, the extended prevalent haplotypes are typically Amerindian, such as TAP1*0101/2-TAP2*0201-QBP3.21-DQB1*0302-QAP*3.1-DQA1*03011-DRB1*0407-B*3501-A*0201 (HF = 16.6%). Thirty-two extended haplotypes were found in Seri, although TAP contributed scarcely to diversity. Mestizos show Amerindian and Caucasian combinations. No difference was detected in the distribution of amino acids in the individual variable sites, between both groups. These findings are the basis for further anthropological studies and to explore the contribution of TAP genes to disease expression in Mexicans.

Jejunojejunal intussusception secondary to lipoma in an adult

Lipoma is a rare cause of adult intussusception. We present the CT findings of an adult patient with jejunojejunal intussusception secondary to submucosal lipoma as the lead point in this case report.

Spontaneous retroperitoneal hemorrhage secondary to subcapsular renal hematoma: MRI findings

Spontaneous retroperitoneal hemorrhage is a rare intraabdominal bleeding. In this report we present a case of a nontraumatic retroperitoneal hemorrhage secondary to spontaneous subcapsular renal hematoma. A 54-year-old patient who was under warfarin therapy, developed subcapsular right renal hematoma. Subcapsular and retroperitoneal hemorrhage were low signal on T1- and T2-weighted images consistent with acute stage of blood. The source of subcapsular hematoma was shown to be the rupture of hemorrhagic renal cyst on MRI. Extension of hemorrhage into the retroperitoneal space anterior to right psoas muscle was also successfully shown on MRI. Patient underwent nephrectomy and retroperitoneal blood was evacuated.

Hybrids of pluripotent and nullipotent human embryonal carcinoma cells: partial retention of a pluripotent phenotype

To investigate whether the failure of human EC cells that do not differentiate is due to the loss of key differentiation-permissive functions or the acquisition of specific inhibitory functions, we tested the ability to differentiate of 2 hybrids produced between a relatively nullipotent human EC cell line, 2102Ep, and a pluripotent human EC cell line NTERA2. Both hybrids, which exhibited an EC phenotype, were able to differentiate readily in response to retinoic acid. Furthermore, 1 hybrid produced a well-differentiated xenograft tumor, which contained, like the NTERA2 tumors, glandular structures, loose mesenchymal tissues and nodules of cartilage, after injection into a SCID mouse. Thus, the failure of 2102Ep EC cells to differentiate is recessive and due to the loss of a key gene function or functions. Nevertheless, the hybrids differed from the pluripotent NTERA2 line by failing to differentiate in neurons, indicating that 2102Ep cells also had acquired a specific, dominantly-acting, inhibitory mutation specific to the neural lineage. Furthermore, the expression of collagen II by one hybrid before and after induction with retinoic suggested a propensity for spontaneous differentiation not evident in the parental NTERA2 cells. Thus, the mechanisms that restrict the differentiation capacity of the nullipotent 2102Ep line are complex and include both recessive and dominant acting factors.

Repair of moderate aortic valve lesions associated with other pathology: an 11-year follow-up

OBJECTIVES

The presence of moderate aortic valve (AV) lesions associated with other pathologies that require surgery presents a problem since ignoring or replacing the valve seems unsatisfactory. AV repair can be an attractive alternative if shown to perform satisfactory.

METHODS

To evaluate this possibility, all consecutive AV patients who underwent operation between July 1988 and July 1999 were reviewed. Out of 1764 AV patients, 239 (14%) underwent repair and 86 (study group) had moderate lesions associated with mitral (73), tricuspid (33), coronary disease (5) and others (8). Mean age was 28 years (range 2--66); 78% were rheumatic, 71% were in sinus rhythm and 71% in NYHA class III--IV.

RESULTS

There were seven hospital deaths (8%) and three patients were lost to follow-up (95% complete). Late mortality was 8% and 10-year actuarial survival was 86 +/- 4.5% (excluding hospital mortality). There were four (5%) embolic events (actuarial freedom 94 +/- 3.5%). Twenty-one patients required reoperation with two mortalities. The AV was not touched in five patients. In the remaining 16, the AV was replaced. Only one patient had isolated AV replacement while in all others, additionally, the mitral, tricuspid, or both required surgery. All reoperated patients had rheumatic etiology. Actuarial freedom from AV dysfunction at 8 years was 68 +/- 7.5%.

CONCLUSIONS

Repair of associated moderate AV lesion is worth considering even in a predominantly young rheumatic population.

Primary epiploic appendagitis: CT manifestations

Inflammation of an epiploic appendage is considered to be a rare cause of acute abdomen. Recently, it has been reported that typical computed tomography (CT) findings of primary epiploic appendagitis (PEA) provide a definitive diagnosis in most of the cases. However, since these papers are only few, they are easily overlooked by the practicing radiologists. Our purpose is to add four new cases to the existing literature and to perform a review of the literature.

The expression and function of cadherin-mediated cell-to-cell adhesion in human embryonal carcinoma cells

Human embryonal carcinoma (EC) cells typically require high cell densities to maintain their characteristic phenotype; they are generally subject to differentiation when cultured at low cell densities, marked by changes in morphology and expression of the surface antigen, SSEA-1. To test whether cadherin mediated cell-to-cell adhesion may be responsible for maintaining an EC phenotype we ascertained that human EC cells generally express E- and P-cadherins, and are subject to cadherin mediated, Ca2+ dependent aggregation. However, in the NTERA2 human EC cell line, inhibition of cadherin mediated adhesion by culture in low levels of Ca2+ did not result in the changes typically seen under low cell density conditions. Low Ca2+ levels also did not affect the pattern of differentiation in these cells following induction with retinoic acid. Therefore, cadherin-mediated cell adhesion does not appear to play a role in maintaining an EC phenotype. On the other hand, culture at both low cell density and in the absence of Ca2+ did result in changes in the patterns of cadherin expression suggesting a feedback regulatory effect of cell-to-cell adhesion. Further, lithium which inhibits the cytoplasmic kinase GSK3beta and hence influences beta-catenin levels did cause differentiation of NTERA2 cells. However, consideration of the phenotype of the resultant cells suggested that this effect may be because of lithium mimicking activation of a Wnt signalling pathway, rather than an effect on signalling consequent upon cadherin mediated cell to cell adhesion.

Spontaneous involution of pulmonary sequestration in children: a report of two cases and review of the literature

BACKGROUND

Two cases of pulmonary sequestration which regressed spontaneously are presented.

OBJECTIVE

To demonstrate the value of imaging studies in the diagnosis and follow-up of some forms of congenital masses of the lung in asymptomatic patients.

MATERIAL AND METHODS

We reviewed the clinical records and imaging studies of two asymptomatic children, one newborn and the other 3 months old, with thoracic masses which demonstrated variable degrees of spontaneous involution.

RESULTS

Abdominal ultrasound performed on the newborn with a palpable mass showed a triangular echogenic mass with a large central feeding vessel arising from the aorta. The mass had disappeared on follow-up US exam performed 6 years later. CT was performed in the 3-month-old patient with a persistent retrocardiac mass. A soft-tissue density mass in the left pulmonary base with a large feeding vessel arising from the aorta was visualised on contrast-enhanced CT. Five years later, a new CT scan showed significant shrinkage of the mass and no vessel.

CONCLUSION

Radiological techniques such as real-time US with Doppler imaging and contrast-enhanced CT may establish the diagnosis of pulmonary sequestration by demonstrating the mass and its systemic vessel, thereby eliminating the need for more aggressive imaging procedures. Partial or total disappearance of these masses represents a further example of involutive pathology and suggests that not all cases of pulmonary sequestration should be surgically treated.

Substitution of the conserved phenylalanine in the S-adenosyl-L-methionine binding site of M.MspI with tyrosine modifies the kinetic properties of the enzyme

Cytosine (C-5)-specific DNA methyltransferases share a set of ten conserved motifs distributed evenly throughout the entire polypeptide chain. The first conserved motif contains a Phe, which is intimately associated with cofactor recognition. In the pseudo-DNA methyltransferase M.SpoI, encoded by the pmt1 gene in Schizosaccharomyces pombe, a Tyr replaces this Phe residue. We describe the properties of a mutant form of M.MspI, a typical cytosine (C-5)-specific DNA methyltransferase, in which Tyr replaces the conserved Phe. This mutant shows differences in ternary complex formation and in the pattern of covalent complex formation with an inhibitory, fluorinated DNA duplex which may be due to anomalous hydrogen bonding between the mutant Tyr hydroxyl group and the catalytic loop of the enzyme or through interference with cofactor binding.

Advantage of Inoue balloon catheter in mitral balloon valvotomy: experience with 220 consecutive patients

Percutaneous mitral balloon valvotomy (PMV) using the Inoue balloon catheter was attempted in 220 consecutive patients with severe symptomatic mitral stenosis. Their age range was 10-63 mean 30 +/- 10 years; 161 patients were females and 59 were males; 29 patients were in atrial fibrillation. Eleven patients were pregnant; 14 patients underwent previous surgical commissurotomy. The procedure was technically successfully performed in 215 (97.7%) patients. The mean fluoroscopy time was 15.5 +/- 6.4 min and mean procedure time was 109 +/- 79 min. Optimal results (group I) was achieved in 207 patients who have mitral score of 7 +/- 1. PMV resulted in decrease in left atrial pressure from 23 +/- 5 to 14 +/- 4 mm Hg (P < 0.001), the mean mitral valve gradient (MVG) decreased from 15 +/- 4 to 6 +/- 3 mm Hg (P < 0.001). The mitral valve area (MVA) by catheter increased from 0.7 +/- 0.2 to 1.7 +/- 0.5 cm2 (P < 0.001) and MVA as determined by echocardiography (2DE) increased from 0.8 +/- 0.1 to 1.9 +/- 0.3 cm2 (P < 0.001). The results were suboptimal in eight patients who have a mitral score of 10 +/- 1 (group II) MVA by catheter increased from 0.7 +/- 0.2 to 1 +/- 0.1 cm2 and Doppler MVA increased from 0.8 +/- 0.1 to 1.3 +/- 0.1 cm2. There were no deaths or thromboembolism. Two patients developed cardiac tamponade; mild mitral regurgitation (MR) developed in 24 patients (11%) and increased by one grade in another 22 patients (10%). Severe MR was encountered in three patients (1.4%). A small ASD (QP/QS < or = 1.3) was detected by oximetry in 5% of patients and by color-flow mapping in 26% of patients. One hundred fifty-eight patients from group I were followed up, for a mean of 32 +/- 12 months; MVA remained at 1.7 +/- 0.4 cm2. Seven patients developed mitral restenosis in group I, and 5 out of 8 patients developed restenosis in group II. We conclude that the hemodynamic results are good and comparable with those reported with double balloon technique. However, the Inoue balloon has several advantages over the double balloon technique: (1) low incidence of mitral regurgitation and ASDs; (2) shorter procedure and fluoroscopy time; and (3) low complication rates and the valve anatomy affects the immediate and late outcome of mitral balloon valvotomy.

Vascular reactivity of arterial coronary artery bypass grafts--implications for their performance

Specific properties of the vessel wall of arteries employed as coronary bypass grafts are thought to play an important role in the short- and long-term performance of these conduits. Heterogeneity in the endothelial and smooth muscle cell function between different arteries may provide particular vessels with properties which will favor them for use as bypass conduits. The aim of this review is to provide an insight into how the vascular reactivity of presently used arterial conduits varies and to discuss the clinical implications of these findings both in terms of flow modulation in response to physiologic and exogenous vasoactive mediators and long-term patency.

HLA antigens in Ameridian groups of two different linguistic families from Colombia

Serological HLA types (A, B, C, DR and DQ loci) were studied in five different Indian tribes (Cubeo, Tucano, Coreguaje, Embera and Noanama) belonging to two distinct linguistic families. For all the MHC loci, the range of variation among the five tribes was enormous. Two tribes, Cubeo and Tucano, showed a wide spectrum of antigenic specificities which seemed to be due to admixture from non-tribal groups, while in the other three tribes the polymorphisms of various HLA loci showed restricted distributions. The gene frequency data, when converted to a kinship matrix and a two-dimensional eigenvector plot, indicated that members of the same linguistic family tend to have greater genetic affinity.

HLA antigens in five Amerindian groups (Yuko, Bari, Tunebo, Guane and Paez) of Colombia: results of 'Expedición Humana'

The serological HLA types (A, B, C and D loci) were studied in five different Indian groups in Colombia. The range of polymorphism was not very restricted in these groups, but there was significant genetic heterogeneity among the five populations in all the HLA loci. The gene frequency data, when converted into a kinship matrix and a two-dimensional eigen vector plot, showed a closer affinity between Bari and Yuko Indians, while Guane, Tunebo and Paez Indians were not only genetically different from the former but also well-differentiated from each other. It seems therefore from this study that geographical proximity may play a greater role than linguistic similarities in the genetic affinities of Colombian Amerindians.

Transcatheter laser atrial septostomy in rabbits

The feasibility of percutaneous transluminal catheter-directed laser (Argon multiline 488/514 nm) atrial septostomy under echocardiographic guidance was studied in eight rabbits. In five animals the interatrial septum was exposed to laser energy for 30 s (n = 1) or for 10 s (n = 4) by using the continuous wave (cw) mode of irradiation. In the other three animals chopped mode of irradiation was applied for 10 s at 7 W. Echocardiography allowed visualization of both atrial cavities and the interatrial septum, the tip of the catheter including the optical fiber tip as well as the flow direction of contrast echoes during the laser firing. Blood clotting with thrombus formation was present following the cw mode of irradiation. The defects created in the interatrial septa of < or = 0.3 mm in diameter had irregular black borders and, histopathologically, were surrounded by a zone of coagulation necrosis of < or = 0.2 mm and vacuolization (vacuoles of < 0.1 mm in diameter). After 30 s of lasering a huge defect was conspicuous in the interatrial septum which extended up to the right and left atrial roof. The chopped mode of irradiation induced less blood clotting and narrow channels of < or = 0.08 mm through the interatrial septa with a small zone of coagulation necrosis of < or = 0.05 mm and without carbonization and vacuolization. This study demonstrates that laser atrial septostomy is technically feasible. However, prior to the extension of the method to humans, further investigation especially considering other laser power sources, possibly more suitable for this application such as Neodymium-YAG or Excimer lasers is warranted.

Scabies of the scalp mimicking seborrheic dermatitis in immunocompromised patients

Two children with acute lymphoblastic leukemia undergoing chemotherapy had a special form of scabies characterized by fine scaling of the scalp simulating seborrheic dermatitis. Pruritus was mild or absent. Immunocompromised children and adults should receive whole-body and scalp antiscabietic treatment.

A simultaneous study of Doppler-echo and catheterization in noninvasive assessment of the left ventricular dp/dt

To confirm the feasibility and accuracy of the method for the noninvasive measurement of the left ventricular dp/dt, 53 patients with mitral regurgitation underwent simultaneous determination of left ventricular dp/dt by continuous-wave Doppler echocardiography and cardiac catheterization. Doppler-determined left ventricular dp/dt is derived from the Doppler mitral regurgitant spectrum by dividing the magnitude of the left ventricular-atrial pressure gradient rise between 1 and 3 m/s of the mitral regurgitant velocity signal by the time taken for this change. Left ventricular dp/dt by Doppler ranged from 629 to 3494 mmHg/s (mean +/- SD, 1971 +/- 785 mmHg/s), and that by catheterization varied between 716 and 3650 mmHg/s (mean +/- SD, 1974 +/- 727 mmHg/s). There was a high correlation (r = 0.93, y = 0.862x + 274.77, SEE = 271 mmHg/s, p < 0.001) of left ventricular dp/dt between the two techniques. It is concluded that left ventricular dp/dt is one of the most commonly used parameters for the evaluation of left ventricular systolic function and that Doppler echocardiography provides a new, accurate and noninvasive method of evaluation.

Noninvasive evaluation of right ventricular and pulmonary artery systolic pressures in patients with ventricular septal defects: simultaneous study of Doppler and catheterization data

The method for evaluating right ventricular and pulmonary artery systolic pressures by subtracting the systolic pressure gradient across the ventricular septal defect from the cuff systolic blood pressure is documented. To confirm the reliability and accuracy of this method, simultaneous continuous wave Doppler echocardiography and left and right cardiac catheterization were performed in 66 patients with congenital ventricular septal defects. The comparisons between the Doppler-derived right ventricular or pulmonary artery systolic pressures and those measured by catheterization yielded an excellent correlation (r = 0.969, y = 1.035x - 3.627, SEE = 8.2 mm Hg, p < 0.001 and r = 0.972, y = 1.012x - 2.904, SEE = 7.6 mm Hg, p < 0.001), respectively. There was a close agreement between the Doppler-derived right ventricular or pulmonary artery systolic pressures and those measured by catheters, and the differences between the two measurements did not differ significantly from zero. It is concluded that Doppler echocardiography offers a reliable and accurate method for noninvasive assessment of right ventricular and pulmonary artery systolic pressures in patients with ventricular septal defects.

Mesothelioma of the atrioventricular node: first successful follow-up after excision

Mesothelioma of atrioventricular nodes may cause congenital heart block and diagnosis is usually confirmed at post-mortem. Awareness of the possibility of the development of this tumour and selective coronary arteriography may help to diagnose this in life.

Intracardiac rhabdomyosarcoma: transesophageal echocardiographic findings and diagnosis

Transesophageal echocardiography (TEE) was performed on a 41-year-old woman who presented with a cerebrovascular accident. TEE confirmed the presence of a morphologically bizarre biatrial tumor with precarious, vigorous motion throughout the cardiac cycle. Surgical intervention was decided on, and the patient underwent cardiac surgery for tumor excision 16 hours after TEE. Intraoperative frozen section diagnosis was spindle cell sarcoma, and subsequent immunohistochemical analysis showed the tumor to be a rhabdomyosarcoma. The data are presented here, and the role of TEE to establish a preoperative diagnosis of intracardiac tumor is discussed.

Surgery for aortic regurgitation in the young: repair versus replacement

Aortic valve replacement in the young patient represents a serious problem in terms of anticoagulation and limited durability of the bioprosthesis. In order to determine the possible advantages of conservative surgery, consecutive patients with aortic regurgitation, aged below 35 and operated upon between July 1988 and July 1990 were analyzed. There were 149 patients (mean age 22 years). The aetiology was rheumatic disease in 122 (81.9%) and 83.2% of the patients were in NYHA class III-IV. Sixty-one valves were replaced (AVR) and 88 (59%) were repaired by a variety of techniques (annuloplasty, cusp unrolling, resuspension or extension). The mean ischaemic times for isolated aortic regurgitation were 73.6 mins for AVR and 80.5 mins for repair. Associated mitral surgery was performed in 94 patients (63%); 33% of these had a valve replacement and 67% a repair. In the AVR group there was 1 hospital death (2.2%), 2 late deaths (3.3%), 3 major embolic events (5%) and one reoperation for infection. In the repair group there were 2 hospital deaths (2.4%), but no late deaths or embolic events. Twelve patients required reoperation which was performed without mortality; this was due to aortic dysfunction in 4 cases (4.6%) and mitral dysfunction in 8. It is concluded that aortic valve conservation in a young, predominantly rheumatic, population can be performed in a significant number of patients with a low mortality and morbidity.

Indications and limitations of aortic valve reconstruction

To elucidate the value of conservative operation for aortic regurgitation, all consecutive patients operated on between July 1988 and July 1990 were reviewed. Of 251 patients with aortic regurgitation, 107 (42.6%) had nonprosthetic operation. The mean age was 23 years, and 90 patients (84.1%) were rheumatic. Two techniques were used: repair (annular and leaflet plasties, 69 cases) and cusp extension with glutaraldehyde-treated pericardium (25 bovine, 13 autologous). There were two hospital deaths (1.8%), both in the repair group, and no late deaths or embolic events. Only 5 patients (4.7%) were anticoagulated. In the repair group there were 12 reoperations, four (5.9%) due to aortic and eight to mitral dysfunction. In the cusp extension group there were two reoperations due to mitral dysfunction. Echocardiographic follow-up showed better results with cusp extension. In conclusion, conservative operation for aortic regurgitation is possible in a high percentage of young rheumatic patients and does not require anticoagulation. Cusp extension is more reliable than repair in terms of early results, although its long-term durability is not yet known.

Surgical approaches to the mitral valve

Different approaches to the left atrium and various techniques of the atriotomy are practiced by cardiac surgeons according to the need for a particular patient and preference of the individual surgeon. Their basic methods, advantages and disadvantages, and our present day techniques are discussed.

Actinic prurigo among the Chimila Indians in Colombia: HLA studies

The Chimila, a Colombian Amerindian group that lives at a low altitude, have a high incidence of actinic prurigo. We present the human lymphocyte antigen (HLA) findings of 43 Chimilas with the disease and of 62 control subjects and show an association of actinic prurigo with the Cw4 antigen.

HLA antigens in the Uitoto Indians and an urban population of Colombia

One hundred individuals from the city of Bogota and 32 Uitoto Indians from the Colombian Amazonia were HLA-typed. The results showed that the two populations differ significantly in the frequencies of the alleles A28, B15, B39, Bw51, Cw2, Cw3 and DRw52. In general, the Uitoto Indians resemble, in their histocompatibility antigens, other Latin-American Indians so far studied.

Tissue response to anodyne medicaments

The tissue-irritating effect of anodyne medicaments was studied via enzyme histochemical evaluation of muscle tissue (screening test) and pulp tissue (usage test). Of the medicaments tested, formocresol was the most irritating, followed by Cresatin, eugenol, and oil of pimenta leaf. The effects of Cresatin, eugenol, and oil of pimenta leaf were not statistically distinguishable.