Biomarcadores Salivales en Pacientes Diagnosticados con Fibrosis Quística, Concepción, 2016 / Salivary Biomarkers in Patients Diagnosed with Cystic Fibrosis, Concepción, 2016

RESUMEN: El odontólogo como profesional integral del área de la salud, debe tener conocimiento acerca de distintas manifestaciones bioquímicas que pueden tener repercusión en la cavidad oral. El objetivo del trabajo fue determinar las manifestaciones bioquímicas y alteraciones en biomarcadores salivales en la cavidad oral producto de la fibrosis quística o del consumo crónico de medicamentos para el tratamiento de la FQ. Se seleccionó un total de cinco personas con fibrosis quística y cuatro personas sanas, pertenecientes a la ciudad de Concepción en la Octava Región de Chile. Se midió pH salival, capacidad buffer, concentración de proteínas totales, tasa de flujo salival estimulado y se determinó presencia de ciertas enzimas salivales en pacientes que padecen la enfermedad. Se pudo evidenciar que el pH salival en sujetos con fibrosis quística tiende a ser mayor a los valores de referencia, la tasa de flujo salival es mucho menor al igual que la capacidad buffer, la concentración de proteínas totales en saliva se encuentra igual a los valores de referencia y se determinó la presencia biomarcadores salivales a través de la técnica de electroforesis. La fibrosis quística afecta de muchas formas a las personas que la padecen, genera cambios a nivel de los biomarcadores salivales como también en la cavidad oral, por lo que el odontólogo debe estar capacitado para identificar estos cambios y poder tratar de la mejor manera a todo tipo de paciente.

ABSTRACT: The dentist as an integral health professional must have knowledge of various biochemical manifestations that may have repercussions on the oral cavity. The objective of the study was to determine the biochemical manifestations and salivary biomarker alterations in the oral cavity resulting from cystic fibrosis or chronic consumption of drugs for the treatment of CF. We selected a total of five people with cystic fibrosis and four healthy people, from the city of Concepcion in the eighth region of Chile. Salivary pH, buffer capacity, total protein concentration, stimulated salivary flow rate and the presence of certain salivary enzymes were measured in patients suffering from the disease. It was observed that the salivary pH in subjects with cystic fibrosis tends to be higher than the reference values, the salivary flow rate and buffer capacity are less than normal, the total protein concentration in saliva is equal to the reference values and the presence of salivary biomarkers was determined through the electrophoresis technique. Cystic fibrosis affects those who suffer the disease in many ways, it generates changes at the salivary biomarker level, as well as in the oral cavity. The dentist must therefore, be able to identify these changes in order to treat them in the best possible approach for all types of patients.

DEVELOPMENT AND IMPLEMENTATION OF TOOLS FOR SELF-MONITORING OF STAFF EXPOSED TO 131I IN NUCLEAR MEDICINE CENTRES OF CHILE.

Currently in Chile, there are about 42 nuclear medicine centres that mainly use 99mTc and 131I in diagnostic and therapeutic procedures. Therefore, staff performs various tasks that increase the risk of internal incorporation and the need to implement routine monitoring programmes. This article shows tools for self-monitoring of staff who exposed to 131I from measurements in thyroid and urine samples, using the gamma cameras of Nuclear Medicine Units. Then, the calibration factors of gamma cameras of participating units were determined, and a one-worker dose was calculated due to internal incorporation, using an Excel spreadsheet for self-monitoring. The worker who handles 131I in one of the studied units was monitored for 6 months. The goal of this study is to implement a routine self-monitoring programme for the estimation of committed effective dose of staff exposed to 131I using gamma cameras in Nuclear Medicine Units of clinical centres in Chile.

Small lesion size measured by colposcopy may predict absence of cervical intraepithelial neoplasia in a large loop excision of the transformation zone specimen.

OBJECTIVE: To evaluate whether colposcopic measurement of the lesion size at diagnosis and/or human papillomavirus (HPV) genotyping can predict the absence of dysplasia in a large loop excision of the transformation zone (LLETZ) specimen in women treated for squamous intraepithelial lesions/cervical intraepithelial neoplasia (SIL/CIN). DESIGN: Prospective observational study. SETTING: Tertiary university hospital. POPULATION: A cohort of 116 women who underwent LLETZ because of biopsy-proven low-grade SIL/CIN that had persisted for 2 years, or because of a high-grade SIL/CIN diagnosed in the referral visit and squamocolumnar junction completely visible (types 1 or 2, according to the International Federation of Cervical Pathology and Colposcopy, IFCPC). METHODS: After LLETZ the women were classified by histology into the study group (absence of SIL/CIN in the surgical specimen, 28/116, 24.1%) and the control group (SIL/CIN in the LLETZ specimen, 88/116, 75.9%). MAIN OUTCOME MEASURES: The size of the lesion determined in the diagnostic colposcopy and the HPV genotype were evaluated in all women. RESULTS: The lesion size was significantly smaller in the study group (25.7 ± 37.8 versus 84.5 ± 81.7 mm2 ; P < 0.001). A lesion size of ≤12 mm2 and HPV types other than 16 or 18 were associated with an absence of SIL/CIN in the LLETZ specimen (P < 0.001 and P = 0.016, respectively). On multivariate analysis only a lesion size of ≤12 mm2 predicted the absence of SIL/CIN (odds ratio, OR 10.6; 95% confidence interval, 95% CI 3.6-30.6; P < 0.001). A lesion size of ≤12 mm2 had a specificity of 90.9% (95% CI 83.0-95.3%) and a negative predictive value of 86.0% (95% CI 77.5-91.6%) to predict the absence of SIL/CIN in the surgical specimen. CONCLUSIONS: Small lesion size in diagnostic colposcopy could predict the absence of SIL/CIN in the LLETZ specimen. Colposcopy measurement of lesion size prior to LLETZ may avoid unnecessary treatment. TWEETABLE ABSTRACT: Small lesion size in colposcopic evaluation might predict the absence of SIL/CIN in an LLETZ specimen.

Expectant management in pregnant women with early and severe preeclampsia and concomitant risk factors.

AIM: The aim of this study was to demonstrate that women with severe early-onset preeclampsia and concomitant risk factors benefit from expectant management. METHODS: This retrospective study was conducted between January 2009 and December 2010. Stable women with severe preeclampsia between 23+6 and 33+6weeks of gestation were admitted to the IOCU for conservative management. They were classified into two groups: those with concomitant risk factors, i.e. associated medical conditions, HELLP syndrome, severe oligohydramnios, fetal growth restriction and multiple pregnancies (group A) and those without (group B). P values lesser than 0.05 were considered statistically significant. RESULTS: No significant differences were found in maternal and perinatal outcomes between groups. Neither were differences observed in pregnancy prolongation (mean: 8.42days (SD±7.462) in group A and 10.5days (SD±8.235) in group B (p=0.391)). At the start of expectant management, 31.8% of fetuses had an abnormal middle cerebral artery Doppler; prior to delivery, this percentage was 77.4%. CONCLUSION: Pregnant women with severe early-onset preeclampsia and associated risk factors benefited from expectant management. During expectant management using a continuous magnesium sulfate regimen, the majority of fetuses showed cerebral vasodilatation. The exact clinical value of this finding should be clarified in further studies.

Virulencia y variabilidad de Porphyromonas gingivalis y Aggregatibacter actinomycetemcomitans y su asociación a la periodontitis / Virulence and variability on Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans and their association to periodontitis

Las periodontitis son un conjunto de patologías de naturaleza inflamatoria y etiología infecciosa producidas por el biofilm patogénico subgingival. Porphyromonas gingivalis y Aggregatibacter actinomycetemcomitans son bacterias periodonto-patógenas que pueden causar daño directo a las estructuras periodontales a través de los diversos factores de virulencia que expresan. Sobre la base de estos factores de virulencia, distintos genotipos y serotipos bacterianos se han descrito, cada uno de ellos con una potencial variable patogenicidad. En esta revisión bibliográfica se describen diferentes factores de virulencia de P. gingivalis y A. actinomycetemcomitans y se discute la variable inmunogenicidad y patogenicidad de los distintos genotipos y serotipos descritos para ellos. Tanto P. gingivalis como A. actinomycetemcomitans poseen diversos factores de virulencia asociados al inicio, progresión y severidad de las periodontitis. En P. gingivalis, los factores de virulencia para los cuales se describen distintos genotipos y/o serotipos son fimbria, LPS y cápsula bacteriana, y en A. actinomycetemcomitans son leucotoxina A, Cdt y LPS. Cada uno de estos distintos genotipos y serotipos induce una respuesta inmuno-inflamatoria diferente en el hospedero y, por lo tanto, se podrían asociar a una variable patogenicidad y podrían determinar las características clínicas de la enfermedad.

Periodontitis represents a heterogenic group of periodontal infections elicited by bacteria residing at the subgingival biofilm. Although this biofilm is constituted by a broad variety of bacterial species, only a limited number has been associated with the periodontitis aetiology, among them Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. Both P. gingivalis and A. actinomycetemcomitans express a number of virulence factors that contribute to direct tissue damage and, based on them, distinct genotypes and serotypes have been described, each one with a potential variable pathogenicity. This review aimed to analyze the different virulence factors described for P. gingivalis and A. actinomycetemcomitans and to discuss the variable immunogenicity and pathogenicity of their serotypes and genotypes. P. gingivalis and A. actinomycetemcomitans express different virulence factors and they determine the initiation, progression, and severity of periodontitis. In P. gingivalis, distinct serotypes and/or genotypes are described based on fimbriae, LPS, and capsule. Additionally, in A. actinomycetemcomitans distinct serotypes and/or genotypes are described based on leucotoxin A, Cdt, and LPS. These distinct serotypes and genotypes induce a differential immunoinflammatory response and, thus, could be associated with variations in pathogenicity and reflected in clinic characteristics of the disease.

Biphasic pro-thrombotic and inflammatory responses after coronary artery bypass surgery.

Early graft failure after coronary artery bypass grafting (CABG) is related to thrombosis and inflammation in the grafted vessel(s). The time courses of, and relationships between, pro-thrombotic and inflammatory responses to CABG surgery have, however, not been well defined. Fifteen patients undergoing CABG were examined before, and 1 h, 1 day, 7 days, and 3 months after surgery. Cellular markers of platelet and leukocyte activation were monitored by whole blood flow cytometry, and plasma markers of pro-thrombotic and inflammatory responses were analyzed by immunoassays. CABG immediately increased circulating P-selectin-positive platelets, leukocyte CD11b expression, and platelet-leukocyte aggregates (PLAs). Thrombin generation (F1 + 2 levels) and cytokine release [tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-8, and IL-10], soluble P-selectin, and soluble E-selectin also increased immediately. These alterations persisted during the first week after surgery, with re-bound increases of circulating activated platelets and PLAs, TNF-alpha, and F1 + 2 on day 7. Platelet and PLA responsiveness to in vitro stimulation was suppressed immediately after CABG, but markedly enhanced 1 week after surgery. After 3 months, plasma soluble P-selectin, F1 + 2, and IL-10, and monocyte CD11b expression were still slightly elevated compared with baseline. In conclusion, CABG induces marked pro-thrombotic and inflammatory responses, which persist for at least 1 week. Platelet activation, platelet reactivity, PLA formation, thrombin generation, and TNF-alpha release show a second peak 1 week after surgery. These findings suggest that intensified and prolonged antithrombotic/inflammatory treatment should be considered after CABG surgery.

Fewer reoperations and shorter stay in the cardiac surgical ward when stabilising the sternum with the Ley prosthesis in post-operative mediastinitis.

OBJECTIVE: Using the Ley prosthesis, a 0.5mm thick titanium alloy plate for stabilising the sternum, is a new method in the treatment of mediastinitis after open-heart surgery. We report a retrospective analysis of our experience with this device. METHODS: One hundred consecutive cases of post-operative mediastinitis in the period 1992-1997 were reviewed. The primary procedure at reoperation for infection was as follows: 52 patients were treated with the Ley prosthesis and 48 patients underwent other conventional procedures. The choice of the surgical technique depended on the attending surgeon. The prosthesis was used more frequently in patients with sternal dehiscence (P<0.001) but otherwise patients' characteristics were similar in the two groups. As a control population for outcome data, 100 uninfected patients were matched with regard to operative procedure, age, sex and date of surgery. RESULTS: The median hospital stay was 48.5 days in the mediastinitis group vs. 14 days in the control group. The all-cause 90-day mortality in the mediastinitis group was 18% vs. 5% in the control group. The 52 patients treated with the Ley prosthesis had a median length of stay in the cardiac surgery ward for 29 days vs. 41.5 days in the mediastinitis group not treated with the prosthesis (P=0.013). However, when the total length of stay including hospitals outside the cardiac surgery ward was taken into account, the prosthesis did not reduce the length of stay. Only 8/52 patients treated with the prosthesis required further surgery vs. 23/48 patients who were not primarily treated with the prosthesis (P<0.001). The Ley prosthesis had no impact on mortality. CONCLUSION: The Ley prosthesis is a valuable adjunct to the treatment of mediastinitis after open-heart surgery. A shorter stay at the cardiac surgery ward and a reduced need for further surgical procedures were observed when using this prosthesis.

No effect of L-arginine supplementation on pulmonary endothelial dysfunction after cardiopulmonary bypass.

BACKGROUND: Acetylcholine is an endothelium-dependent vasodilator through the L-arginine-nitric oxide pathway. After ischemia-reperfusion this effect is attenuated, also demonstrated in the pulmonary circulation after cardiopulmonary bypass. Administration of L-arginine has been shown to have a protective effect on endothelial function in reperfusion injury. The aim of the current study was to test the possible effect of L-arginine on the acetylcholine reactivity in the pulmonary circulation after cardiopulmonary bypass. METHODS: Thirty-five patients with ischemic and/or valvular heart disease were investigated in a randomized, double-blinded, placebo-controlled study. The patients were divided into three groups. Group 1: high dose L-arginine (n=10), group 2: low dose L-arginine (n=10), group 3: placebo, no L-arginine, (n=15). The acetylcholine reactivity was tested with measurements of pulmonary vascular resistance before surgery and 1, 2 and 3-4 h after cardiopulmonary bypass. RESULTS: After cardiopulmonary bypass an attenuation of the acetylcholine reactivity over time was observed in all groups, with no differences between groups. CONCLUSION: In the current study L-arginine had no protective effect on the pulmonary endothelium after cardiopulmonary bypass, measured as reactivity to an infusion of acetylcholine.

Decreased pulmonary vascular resistance during nasal breathing: modulation by endogenous nitric oxide from the paranasal sinuses.

Nitric oxide is present in high concentration in the human nasal airways. During inspiration through the nose a bolus is transported to the lungs. In a randomized cross-over study the effect of two different patterns of breathing, nasal breathing and mouth breathing, was evaluated in 10 patients (mean age 65 years), breathing room air the morning of the first post-operative day after open heart surgery. Nasal breathing is defined as inspiration through the nose and expiration through the mouth, whilst mouth breathing is the converse of this: inspiration through the mouth and expiration through the nose. Pressure in the pulmonary artery and left atrium or pulmonary artery wedge was measured together with thermodilution cardiac output and arterial and mixed venous oxygenation and acid-base parameters. Pulmonary vascular resistance index (PVRI), venous admixture and alveolar-arterial gradient were calculated. Nasal breathing resulted in a lower PVRI, 256 dyn s cm-5 cm-2 vs. 287 (P < 0.01). The oxygen and carbon dioxide tension and pH of arterial and mixed venous blood, venous admixture and the alveolar-arterial gradient remained unchanged. The decreased level of PVRI during nasal breathing compared to that during mouth breathing supports the notion, that endogenous nitric oxide acts as an airborne messenger to modulate the pulmonary vascular tone during normal breathing.

Asian and Pacific Islander American HIV community-based organizations: a nationwide survey.

A national survey was conducted to (a) ascertain the status of HIV prevention among community-based organizations targeting APIs in the United States, (b) define technical assistance needs among these organizations, and (c) determine their involvement in the HIV community planning process. Of the 80 surveys sent out, 49 (61%) completed responses were received. Filipinos, Chinese, Vietnamese, Cambodians, and multiracials were the subpopulations targeted the most often, and, not surprising, Tagalog, Cantonese, Mandarin, Vietnamese, Cambodian, Korean and Japanese were the Asian languages most widely in use. Gay men, bisexual men, and youth were targeted most frequently by HIV prevention efforts. Of all the largest ethnic subpopulations, Asian Indian is the only group with no community-based organization that exclusively targets them for HIV prevention. More than 95% of respondents reported conducting some type of evaluation; the size of the budget and organization often determined the evaluation strategies used. Program development, staff development, and program evaluation were the most frequently reported areas of technical assistance requested. A majority of the respondents (79%) reported being involved with the HIV prevention community planning process where APIs were represented on state/local community planning groups, they did not rate the performance of the community planning process highly. We recommend providing technical assistance in fund-raising, program evaluation, and participation in the HIV community planning process.

Altered reactivity to acetylcholine in the pulmonary circulation after cardiopulmonary bypass is part of reperfusion injury.

STUDY OBJECTIVE: To investigate whether a time sequence of acetylcholine (ACH) reactivity indicative of endothelial reperfusion injury could be demonstrated in the pulmonary circulation in patients after cardiopulmonary bypass (CPB). DESIGN: Prospective study. SETTING: Operating theater and intensive care unit of a university hospital. PATIENTS: 10 ASA physical status III and IV patients with ischemic or valvular heart disease. INTERVENTIONS: Pulmonary vascular resistance index (PVRI) was measured before and during an infusion of ACH. This procedure was done after induction of anesthesia but before surgery, immediately after weaning from bypass, and at 1 to 1.5 and 4 hours after CPB. MEASUREMENTS AND MAIN RESULTS: ACH caused a decrease in PVRI before (p < 0.01) and directly after CPB (p < 0.05) but not at 1 to 1.5 or 4 hours after bypass. CONCLUSIONS: The maintained reactivity to ACH directly after CPB, followed by no reaction at 1 to 1.5 and 4 hours, was in agreement with experimental findings and indicates endothelial reperfusion injury caused by the period with no blood flow through the pulmonary artery during CPB and subsequent reperfusion.

Elevated serum levels of S-100 after deep hypothermic arrest correlate with duration of circulatory arrest.

OBJECTIVE: Cerebral damage is a major problem after reconstructive surgery of the aortic arch and the descending aorta. Current protective strategies, including deep hypothermia and retrograde cerebral perfusion, are used to prolong the tolerated duration of circulatory arrest, and the latter may also decrease the possibility of air/particle embolization. The aim of the current study was to investigate whether the neurochemical marker S-100 is related to the duration of circulatory arrest, when the influence of embolic injury has been minimized by the use of retrograde cerebral perfusion during the last part of circulatory arrest. METHODS: Arterial serum levels of S-100 were followed before, during and after reconstructive surgery of the thoracic aorta during deep hypothermic arrest in ten adults. Retrograde cerebral blood perfusion was used during the latter part of the arrest period in eight of the ten patients. Neurologic status was followed daily. RESULTS: All patients survived the operation. The median (range) duration of cardiopulmonary bypass (CPB) was 184.5 (121-386) min. The median duration of circulatory arrest and retrograde cerebral perfusion was 50 (3-118) min and 16 (0-84) min, respectively. S-100 increased from 0.10 (0.02-0.18) microg/l preoperatively to 2.37 (0.64-10.80) microg/l after CPB (P<0.01), followed by a decrease to 0.79 (0.21-2.64) microg/l on the first postoperative day (P<0.01). The duration of circulatory arrest correlated with S-100 levels after CPB (r(S) = 0.71, P<0.05) and even better with the S-100 levels on the first postoperative day (r(S) = 0.83, P<0.01). However, there was no significant correlation between duration of arrest and duration of CPB. The duration of circulatory arrest without retrograde cerebral perfusion correlated well with S-100 levels on the first postoperative day (r(S) = 0.88, P<0.01), but not significantly with S-100 levels after CPB. CONCLUSIONS: S-100 levels after aortic surgery with deep hypothermic arrest correlate with the duration of circulatory arrest, indicating that the duration of circulatory arrest is damaging to the brain despite the use of deep hypothermia and partial retrograde cerebral perfusion. The highest correlation between S-100 and duration of arrest was seen on the first postoperative day. S-100 appears to perform well under clinical circumstances as a sensitive and discriminative marker for neuronal injury.

[Doppler echocardiography in endomyocardial fibrosis]. / Ecocardiografía Doppler en la fibrosis endomiocárdica.

Twelve patients with endomyocardial fibrosis with angiographic and/or histologic corroboration were studied with Doppler echocardiography with the purpose of describing the echocardiographic features and identify the affected sites. The average age was 41 years (range 16 to 59 years), 2 men and 10 women. Three patients (25%) had isolated right ventricular involvement, one patient (8%) left ventricular, 8 patients (66%) both ventricular. Our Doppler echocardiographic findings were: right atrium enlargement (91%), right ventricle outflow dilatation (83%), paradoxical septal motion (83%), left atrial enlargement (33%), mitral and tricuspid valve prolapse (50%), pericardial effusion (41%), mitral regurgitation (75%), tricuspid regurgitation (100%), apex obliteration (50%) and a restrictive type flow pattern (50%). Doppler echocardiography is a useful method for the diagnosis of endomyocardial fibrosis, the finding of normal or small ventricles associated with apex obliteration and enlarged atria, mitral or tricuspid regurgitation and a restrictive type flow pattern are characteristics of this disease. In our population, the isolated or predominantely right ventricular involvement is the most common finding as it represented 83% of the cases.

Cerebral lactate release after circulatory arrest but not after low flow in pediatric heart operations.

Arteriovenous (jugular bulb) differences in blood lactate were followed throughout the procedure and until 18 hours postoperatively in 17 children undergoing congenital heart operations during profound hypothermia. Transcranial Doppler sonography was used to monitor changes in blood flow velocity in the middle cerebral artery. Ten children had a period of total circulatory arrest (39 +/- 6 minutes) during profound hypothermia (arrest group). Another 7 children had continuous but reduced pump flow (0.6 to 1.2 L/m2) throughout hypothermic cardiopulmonary bypass (low-flow group). The mean age was 7.3 +/- 1.3 months in the arrest group and 7.9 +/- 2.2 months in the low-flow group. The mean time on bypass was 90 +/- 10 minutes in the arrest group and 75 +/- 9 minutes in the low-flow group. The velocity of blood flow in the middle cerebral artery decreased significantly (p < 0.05) in both groups to less than 50% of the preoperative level during hypothermia and increased during and after rewarming. Differences in blood lactate level were significantly less than zero (p < 0.05) from the start of rewarming until 3 hours after the end of cardiopulmonary bypass in the arrest group, whereas differences in blood lactate level remained close to zero in the low-flow group. We conclude that circulatory arrest during profound hypothermia is followed by a period with release of lactate from the brain, indicating anaerobic cerebral metabolism and possibly disturbed cerebral aerobic metabolism. This study argues for the avoidance of circulatory arrest whenever possible.

Absent diastolic cerebral blood flow velocity after circulatory arrest but not after low flow in infants.

It is controversial whether profound hypothermia (15 degrees C) provides adequate cerebral protection during a limited period of total circulatory arrest during pediatric cardiac surgery. In the present study, transcranial Doppler echography was used to monitor the blood flow velocity (BFV) pattern in the middle cerebral artery (MCA). The purpose of the study was to investigate the influence of a period of circulatory arrest on MCA BFV, as judged from the reperfusion flow velocity pattern. The MCA BFV was studied in 22 small children undergoing profound hypothermic cardiac operations after induction of anesthesia. Twelve of the children had a period of profound hypothermic circulatory arrest (15 to 74 minutes; arrest group). Circulation was maintained in the remaining 10 children (nonarrest group). Time-averaged MCA BFV was decreased and diastolic BFV was absent immediately after cardiopulmonary bypass in 10 of 12 children in the arrest group. In contrast, only 1 of 10 patients in the nonarrest group (p < 0.05) showed this pattern. Diastolic BFV normalized 54 to 328 minutes after the arrest in the arrest group. Circulatory arrest during profound hypothermia is followed by a period of low cerebral perfusion, whereby time-averaged MCA BFV is decreased and MCA BFV is absent during diastole. We speculate that this can be explained by an increase in intracranial pressure after brain edema.

[Atherosclerotic ischemic cardiopathy in patients with dextrocardia in situs viscerum inversus]. / Cardiopatía isquémica aterosclerosa en pacientes con dextrocardia en situs viscerum inversus.

We describe the incidence, clinical, radiologic, electrocardiographic, echocardiographic and angiographic findings of two cases with dextrocardia in situ viscerum inversus with ischaemic heart disease. The first patient had coronary artery saphenous bypass graft and is currently asymptomatic with a negative maximal stress test. The other patient with diabetes mellitus and unfavorable coronary anatomy was not operated and is currently with stable angina on class II of the NYHA. The electrocardiographic, echocardiographic and angiographic strategies are commented.

[Balloon valvuloplasty in stenotic bioprosthesis]. / Valvuloplastía con balón en bioprótesis estenóticas.

The results of balloon valvuloplasty performed on five patients with stenotic bioprosthesis treated in the Hospital de Cardiología Centro Médico Nacional Siglo XXI, are presented. All five bioprosthesis were right sided, two in tricuspid position, one in pulmonary valve position and two in valvulated conduits from right ventricle to pulmonary artery. In all cases a pressure gradient reduction was achieved, an improvement of clinical functional class and heart failure manifestations were obtained. Mansfields balloons were used. One in two patients, and two balloons in three. We had not complications with the procedure. We conclude that balloon valvuloplasty on bioprosthesis is a safe and dependable procedure to be used in right sided bioprosthesis.

[Doppler echocardiography assessment of tricuspid valve prosthesis with normal function and with dysfunction due to obstruction]. / Evaluación mediante ecocardiografía Doppler de las prótesis valvulares tricuspídeas con función normal y con disfunción por obstrucción.

UNLABELLED: In order to know the normal ranges of the maximum velocity and the pressure half-time between normal functioning tricuspid prostheses and malfunctioning tricuspid prostheses due to obstruction, we studied 25 patients with tricuspid prostheses (11 mechanical and 14 biological); they were divided in 2 groups: group I: 14 patients without clinical evidence of malfunction and; group II: 11 patients with malfunction due to obstruction confirmed by catheterization, surgery and/or necropsy. The peak gradient was estimated by the modified Bernoulli equation and the prosthetic valve area by the pressure halftime method. RESULTS: the mean peak velocity in group I was 147 +/- 18 cm/sec versus 165 +/- 16 cm/sec (p NS) in group II. The mean pressure half-time in group I was 124 +/- 20 msec versus 355 +/- 48 msec (p less than 0.001) in group II. CONCLUSIONS: 1. A pressure half-time greater than 200 msec is very suggestive of malfunction due to obstruction (p less than 0.001). 2. There are normo-functioning tricuspid prostheses with prolonged pressure half-time, and the values that divides these groups from those with malfunction is small: 199 and 244 msec, that is why we suggest that every patient has to have his her own echocardiographic control in the immediate postoperative period.

[Medico-surgical experience in dysfunction of heart valve prostheses. Report of 55 cases]. / Experiencia médico-quirúrgica en la disfunción de prótesis valvulares cardíacas. Reporte de 55 casos.

The medical and surgical outcome of 55 patients with prosthetic valve disfunction are reported (39 bioprosthesis and 16 mechanical). Fifty patients were operated and five had medical treatment. The group of patients with mechanical prosthesis had a functional class of 2.4 +/- .74 vs patients with bioprosthesis who had a functional class of 2.8 +/- .71. Forty eight patients (87%) had congestive heart failure, four systemic emboli and three infective endocarditis. Three cases with mechanical prosthesis in tricuspid position were subjected to thrombolysis with streptokinase and experienced clinical and echocardiographical improvement. Time elapsed from original implantation and valve disfunction was 66 +/- 56 months for mechanical prosthesis vs 108 +/- 37 months in bioprosthesis (p less than 0.01), three patients died at surgery and two during the waiting period. All deaths resulted from cardiogenic shock. All of them were previously on functional class IV.

[The mortality determinants in 93 cases operated on for aortic stenosis]. / Determinantes de mortalidad en 93 casos operados de estenosis aórtica.

We report 93 cases of severe aortic stenosis. We discuss their clinical data, hemodynamic parameters, and surgical outcome. The surgical mortality and variables determining this event evaluated in groups: A (deaths) and B (survivors). Functional class (mean = 2.5 vs 2.0 p less than 0.05) was statistically as determinant for mortality as were also: transaortic gradient (group A mean = 110 +/- 37 mmHg vs group B mean = 82 +/- 31 p less than 0.005), and ejection fraction (group A mean = 55 +/- 13.7 vs group B mean = 64 +/- 14.8 p less than 0.005). Neither time of cardiopulmonary bypass nor aortic clamping were determinants for mortality. Our results are similar to those reported in other groups. Mortality rates, are determined basically by deterioration of left ventricular function, and by the severity of transaortic gradient.