Recurrent asthma exacerbations: co-existing asthma and common variable immunodeficiency.

Common variable immunodeficiency is characterized by impaired B-cell differentiation and defective immunoglobulin production manifesting as recurrent respiratory tract infections. While the condition can masquerade as asthma, late diagnosis of CVID in known asthmatic is rarely reported.We present the case of a 43-year-old lady with recurrent episodes of wheeze, cough, sinusitis and multiple lower respiratory tract infections. Transiently responsive to antibiotics and steroids. These episodes had been occurring for many years and she had a longstanding clinical diagnosis of asthma.As part of her work up for recurrent respiratory tract infections a CT thorax was performed and demonstrated bronchiectasis. Further tests including Immunoglobulin levels revealed critically low IgG, IgM, and IgA levels. Immunoglobulin replacement therapy was commenced with a reduction in exacerbation frequency and severity, and objective improvement of asthma control. Subsequent lung function tests demonstrated reversible airflow limitation (obstructive lung function with 13% reversibility in FEV1 post-bronchodilator) consistent with asthma.Our case illustrates the importance of searching for alternate and co-existent diagnoses in patients diagnosed with asthma who are unresponsive to conventional therapy. We believe that serum immunoglobulin measurement should form a component of such a workup.

Interactions between Plagiotremus spp., Labroides dimidiatus and their clients: evidence for behavioural niche partitioning.

This study employed community analysis and behavioural field observations to explore the inter-specific interactions between fangblenny species (Plagiotremus spp.), the cleaner wrasse Labroides dimidiatus and their target species and found that the presence of Plagiotremus spp. did not affect the total amount that L. dimidiatus cleaned but it did reduce the amount L. dimidiatus cleaned key prey species of the Plagiotremus spp. The behavioural interactions between adult L. dimidiatus and their clients changed in response to the presence of Plagiotremus spp., but the results suggested the potential cost of Plagiotremus spp. on L. dimidiatus may be offset by behavioural niche partitioning.

Comparison of cold knife cone biopsy and loop electrosurgical excision procedure in the management of cervical adenocarcinoma in situ: What is the gold standard?

OBJECTIVE: To compare the outcomes of patients with cervical adenocarcinoma in situ (ACIS) treated with cold knife cone (CKC) biopsy or loop electrosurgical excision procedure (LEEP) for the treatment of cervical adenocarcinoma in situ (ACIS). STUDY DESIGN: This is a retrospective, population-based cohort study of Western Australian patients with ACIS diagnosed between 2001 and 2012. Outcomes included pathological margin status and the incidence of persistent or recurrent endocervical neoplasia (ACIS and adenocarcinoma) during follow-up (<12 months) and surveillance (≥12 months) periods. RESULTS: The study group comprised 338 patients including 107 (32%) treated initially by LEEP and 231 (68%) treated by CKC biopsy. The mean age was 33.2 years (range 18 to 76 years) and median follow-up interval was 3.6 years (range <1 year to 11.8 years). Overall, 27 (8.0%) patients had ACIS persistence/recurrence while 9 (2.7%) were diagnosed with adenocarcinoma during the follow-up and surveillance periods. No patient died of cervical cancer within the study period. There were no significant differences in the incidence of persistent and/or recurrent endocervical neoplasia according to the type of excisional procedure. Patients with positive biopsy margins were 3.4 times more likely to have disease persistence or recurrence. CONCLUSION(S): LEEP and CKC biopsy appear equally effective in the treatment of ACIS for women wishing to preserve fertility. Patients undergoing conservative management for ACIS should be closely monitored, particularly if biopsy margins are positive in initial excision specimens. Patients and their clinicians should be aware of the potential risks of residual and recurrent disease.

A new approach for the automatic evaluation of the solidification structure in steel using orientational entropy filtering.

We present a new method for the automatic evaluation of the dendritic solidification structure in metallurgical micrographs of solidified steel. The evaluation of the microstructural parameters such as the primary dendrite arm spacing and the primary grain size are of high importance due to their direct relationship with the internal quality and mechanical properties of the cast product. Given the repeated geometric features in the micrographs and the regular pattern in colour intensity, we applied a filter mask to determine the local entropies within the masks in order to detect the centre coordinates of each individual dendrite. The orientation of the dendrites was determined by rotating the filter mask over each pixel to find the orientation which corresponds to the lowest entropy value. The segmentation of the microstructure was then performed via Delaunay tessellation and subsequent transformation of the triangular mesh into a rectangular grid, enabling the determination of the desired microstructural parameters.

Partial anomalous pulmonary venous connection: diagnosis by transesophageal echocardiography.

OBJECTIVE: This study sought to demonstrate that with proper technique, identification of the normal and abnormal pulmonary venous connection can be made with confidence using transesophageal echocardiography (TEE). BACKGROUND: Partial anomalous pulmonary venous connection (PAPVC) is an uncommon congenital anomaly whose diagnosis has classically been made using angiography. METHODS: We performed a retrospective review of all patients of all ages with PAPVC diagnosed at the Mayo Clinic who had undergone TEE because of either right ventricular volume overload or suspected intracardiac shunting by transthoracic echocardiography or intraoperatively. RESULTS: A total of 66 PAPVCs were detected in 43 patients (1.5/patient); in 2 additional patients, TEE suggested, but did not diagnose, PAPVCs. Shortness of breath was the most common presenting symptom (42.2%), followed by heart murmur and supraventricular tachycardia. Right-sided anomalous veins were identified in 35 patients (81.4%), left-sided in 7 (16.3%) and bilateral in 1 (2.3%). There was a single anomalous connecting vein in 23 patients (53.5%), two in 18 (41.9%), three in 1 (2.3%) and four in 1 (2.3%). The connecting site was the superior vena cava (SVC) in 39 veins (59.1%), right atrial-SVC junction in 6 (9.1%), right atrium in 8 (12.1%), inferior vena cava in 1 (1.5%) and the coronary sinus in 2 (3.0%). Ten anomalous left pulmonary veins were connected by a vertical vein to the innominate vein (15.1%). Sinus venosus atrial septal defect (ASD) was the most common associated anomaly in 22 patients (49%), followed by ostium secundum ASD in 6 and patent foramen ovale in 4. Fifteen patients had an intact atrial septum. Thirty-one patients (68.8%) underwent surgical repair. PAPVC was confirmed in all patients, including the two whose TEE results were suggestive of PAPVC. All 49 PAPVCs detected by TEE preoperatively were confirmed at the time of operation. CONCLUSIONS: TEE is highly diagnostic for PAPVC and can obviate angiography. Accurate anatomic diagnosis may influence the need for medical and surgical management. TEE should be performed in patients with right ventricular volume overload when the precordial examination is inconclusive.

Remote telemedical interpretation of neonatal echocardiograms: impact on clinical management in a primary care setting.

OBJECTIVE: The purpose of this study was to evaluate the utility of telemedical echocardiographically assisted neonatal cardiovascular evaluation in a primary care setting. BACKGROUND: Neonates with congenital heart disease are frequently born far from pediatric subspecialty centers and can be clinically unstable at presentation. Recent advances in telecommunication technology have made it possible to transmit echocardiographic images over long distances. This technology may be beneficial to newborns with heart defects who are born in primary care centers. METHODS: A retrospective review of all telemedical echocardiograms obtained from neonates (aged 1 day to 30 days) was performed. A telemedical link was created using a T-1 transmission line and a standard voice telephone line between the Mayo Clinic, Rochester, Minnesota (pediatric cardiology site), and the Altru Clinic, Grand Forks, North Dakota (primary care site), which is a general pediatric practice 400 miles from Rochester. Neonates with possible cardiac disorders were identified by the general pediatricians, who then requested telemedical echocardiography. RESULTS: The 133 neonates had 161 T-1 echocardiograms. Median patient age was two days (range, one day to 29 days). One hundred thirty-two of 133 initial echocardiograms (99%) were obtained because of urgent indications. Transmitted images provided adequate diagnostic information in all patients. Seventy-nine neonates (59%) had a change in medical management or required cardiology follow-up. An immediate change in management occurred in 32 patients (24%), including seven in whom emergency transfer was either arranged or avoided. CONCLUSIONS: Telemedical echocardiography provides accurate diagnostic data in neonates. Rapid telediagnosis facilitates appropriate care of sick neonates with possible congenital heart disease in the primary care setting. Unnecessary long-distance transfers can be avoided with this technology.

Improved early morbidity and mortality after Fontan operation: the Mayo Clinic experience, 1987 to 1992.

OBJECTIVES: This study sought to evaluate changes in early morbidity and mortality as well as predictors of outcome in our most recent 339 patients undergoing modified Fontan operations. BACKGROUND: The Fontan operation is the preferred definitive palliation for patients with functional single ventricles. Previously reported early mortality rates after Fontan operation have been substantial. METHODS: Records of 339 consecutive patients who had a Fontan operation at the Mayo Clinic between 1987 and 1992 (recent cohort) were reviewed. This cohort was compared with the previous 500 patients who had Fontan operations performed between 1973 and 1986 (early cohort). RESULTS: Recently, overall early mortality after Fontan has decreased significantly compared with that for the early cohort (from 16% to 9%, p = 0.002). This decline occurred despite increased anatomic complexity of patients. Short-term posthospital survival has also improved significantly in recent patients. One-year survival improved to 88% from 79%, and 5-year survival to 81% from 73% (p = 0.006). Patients with common atrioventricular valves and those who took daily preoperative diuretic medication or had either postoperative renal failure or elevated postbypass right atrial pressure were at increased risk for early mortality. Young age was not found to be a risk factor for early mortality. Early mortality for patients with heterotaxia decreased dramatically: recent 30-day mortality was 15% compared with 41% in the early heterotaxy cohort. CONCLUSIONS: Many factors may have contributed to decreased early mortality after Fontan. Improved patient selection, younger age at time of operation, refinements in surgical techniques and postoperative management may all have had important roles. Proposed technical modifications of the Fontan operation must be evaluated in light of these improved results.

Predicting baseline laparoscopic surgery skills.

BACKGROUND: Laparoscopic surgery requires specialized dexterity even beyond that required for open surgery. Decreased tactile feedback, different eye-hand coordination, and translation of a two-dimensional video image into a three-dimensional working area are just some of the obstacles in the performance of laparoscopic surgery. Possession of certain nonsurgical skills may help in overcoming some of these obstacles. Prediction of baseline laparoscopic surgery skills may help further to refine the education of basic laparoscopic surgery skills. This investigation explores whether nonsurgical skills and demographic data can predict baseline laparoscopic surgery tasks. METHODS: First- and second-year students were given a survey regarding nonsurgical dexterity skills. The survey inquired about typing skills, play with computer games, ability to sew, skill with music instruments, use of chopsticks, and experience operating tools. Demographic data were requested as well. All the students underwent four tasks: placing a piece of bowel in a retrieval bag, placing a stapler on the bowel, measuring a piece of bowel, and performing a liver biopsy in a porcine animal model. Both objective (time and error) and subjective evaluation were assessed for all the tasks. Statistical analysis using analysis of variances (ANOVA) Kruskal-Wallis test with post hoc tests, two-tailed unpaired t-tests/Mann-Whitney test, and Fischer's exact tests/chi-square tests was performed when appropriate. RESULTS: There were 68 students in this investigation. Gender, medical student year, ethnicity, desire to enter a surgical field, and age were not associated with increased performance in any of the tasks. Chopstick use was associated with statistically significantly better mean time in placing a piece of bowel in a retrieval bag and measuring a piece of bowel (p < 0.04). The other nonsurgical dexterity skills did not statistically increase performance, as indicated by time, errors, or subjective scores, for the four tasks. CONCLUSIONS: It is difficult to predict baseline laparoscopic surgery skills.

Origins of skeletal pain: sensory and sympathetic innervation of the mouse femur.

Although skeletal pain plays a major role in reducing the quality of life in patients suffering from osteoarthritis, Paget's disease, sickle cell anemia and bone cancer, little is known about the mechanisms that generate and maintain this pain. To define the peripheral fibers involved in transmitting and modulating skeletal pain, we used immunohistochemistry with antigen retrieval, confocal microscopy and three-dimensional image reconstruction of the bone to examine the sensory and sympathetic innervation of mineralized bone, bone marrow and periosteum of the normal mouse femur. Thinly myelinated and unmyelinated peptidergic sensory fibers were labeled with antibodies raised against calcitonin gene-related peptide (CGRP) and the unmyelinated, non-peptidergic sensory fibers were labeled with the isolectin B4 (Bandeira simplicifolia). Myelinated sensory fibers were labeled with an antibody raised against 200-kDa neurofilament H (clone RT-97). Sympathetic fibers were labeled with an antibody raised against tyrosine hydroxylase. CGRP, RT-97, and tyrosine hydroxylase immunoreactive fibers, but not isolectin B4 positive fibers, were present throughout the bone marrow, mineralized bone and the periosteum. While the periosteum is the most densely innervated tissue, when the total volume of each tissue is considered, the bone marrow receives the greatest total number of sensory and sympathetic fibers followed by mineralized bone and then periosteum. Understanding the sensory and sympathetic innervation of bone should provide a better understanding of the mechanisms that drive bone pain and aid in developing therapeutic strategies for treating skeletal pain.

Usefulness of the myocardial performance index for assessing right ventricular function in congenital heart disease.

Quantitative assessment of ventricular function in patients with congenital heart disease is often challenging due to distorted ventricular geometry. A myocardial performance index (MPI) has been reported in adults and children that is a Doppler-derived nongeometric measure of ventricular function. The MPI measures the ratio of isovolumic time intervals (isovolumic contraction time and isovolumic relaxation time) to ventricular ejection time. The effects of altered ventricular preload or afterload on the MPI have yet to be determined. This study assesses the impact of altered preload or afterload on right ventricular (RV) function and the RV MPI in the clinical setting of congenital heart disease. Patient groups were compared with normal pediatric and adult populations before and after repair of their congenital heart lesion. Patients with large atrial septal defects (ASDs) represented the clinical setting of increased ventricular preload, whereas patients with isolated pulmonary valve stenosis represented increased RV afterload. Patients with congenitally corrected transposition of the great arteries (CC-TGA) with severe left atrioventricular valve regurgitation represented a combined increase in RV preload and afterload. The RV MPI in 152 normal children (ages 3 to 18 years) and 37 adults (ages 18 to 51 years) was 0.32 +/- 0.03 and 0.28 +/- 0.04, respectively. In pediatric patients (n = 45) and adult patients (n = 40) with ASD, the RV MPI was 0.35 +/- 0.09 (p = NS) and 0.38 +/- 0.04 (p < 0.01 compared with normal adults), respectively. Patients with pulmonary stenosis (n = 21, ages 1 day to 19 years) had a RV MPI of 0.32 +/- 0.06 (p = NS). CC-TGA patients had a RV MPI of 0.72 +/- 0.17 (p < 0.001). No significant change in the RV MPI was seen in any postoperative patient group despite relief of RV volume or pressure overload. Thus, the MPI is a quantitative measure of RV performance that is appears to be relatively independent of changes in preload or afterload in the clinical setting.

Effects of 12-O-tetradecanoylphorbol-13-acetate and mezerein on gamma radiation-induced DNA repair in resting bovine lymphocytes.

The present study was undertaken to determine the effect of the potent tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA) on gamma radiation-induced DNA repair in resting (Go) lymphocytes. Mezerein, a non-promoter but a co-mitogen in lymphocytes, was used as a control agent. It was previously proposed that a possible mechanism for the action of tumor promoters was through the inhibition of DNA repair processes. Our results indicate that TPA does not inhibit DNA repair following gamma irradiation of Go lymphocytes. These data support the hypothesis that the tumor promoting ability of TPA is not a result of impaired repair of potentially mutagenic lesions in DNA.

Evaluation of testicular hCG binding in unilaterally cryptorchid rats following administration of ethane dimethane sulphonate (EDS).

Administration of ethane dimethane sulphonate (EDS) (75 mg/kg) to unilaterally cryptorchid rats, results in a rapid decline in serum testosterone levels and a marked reduction in hCG binding to homogenates of scrotal and cryptorchid testes, consistent with the destruction of Leydig cells within the testes as shown by morphological and morphometric analysis. Between 3 and 7 days after EDS, serum LH and FSH levels rise, LH to levels found in castrate rats. hCG binding begins to recover in scrotal testes, reaching 32% of control values 28 days after EDS. However, the recovery of hCG binding to cryptorchid testes is more rapid, reaching 51% of control levels by 21 days which coincides with the re-establishment of serum testosterone to normal levels. Since a different rate of recovery is observed for hCG binding to scrotal and cryptorchid testes, and both testes are exposed to the same circulating levels of LH and FSH, the likely stimulus for recovery of hCG binding and regeneration of Leydig cells is intratesticular in origin. This supports the concept that local factors, released following damage to the seminiferous epithelium by cryptorchidism, play a role in the differentiation and growth of Leydig cells within the testis.

The effects of ethane dimethane sulphonate (EDS) on bilaterally cryptorchid rat testes.

A single dose of ethane dimethane sulphonate (EDS) given to adult male rats has a specific destructive effects on Leydig cells, which are removed from the intertubular area by macrophages. This is associated with a decrease in testosterone (T) and a rise in serum FSH and LH for 21-28 days after EDS. Recovery of Leydig cells occurs from connective tissue precursors. This study uses the bilaterally cryptorchid rat to investigate the influence of local factors from the seminiferous tubules on the restoration of Leydig cell morphology and function. Morphometric data of intertubular tissue, hCG binding, serum T, FSH and LH levels all indicate that the Leydig cell population in cryptorchid testes is more rapidly restored from connective tissue cells when compared to the normal situation. The precise mechanism for this faster recovery will require further study.

Idiopathic restrictive cardiomyopathy in childhood: diagnostic features and clinical course.

OBJECTIVE: To describe the clinical course and outcome of children with idiopathic restrictive cardiomyopathy (IRCM) and to present the Doppler echocardiographic features of this disease in childhood. DESIGN: We reviewed the Mayo Clinic patient database for the period from 1975 to 1993 to identify children who underwent assessment for IRCM. MATERIAL AND METHODS: Clinical records and diagnostic studies, including two-dimensional (2-D), M-mode, and Doppler echocardiograms, were reviewed for each patient. Characteristics were analyzed statistically to determine potential predictors of outcome. RESULTS: Eight children (five girls and three boys) were diagnosed with IRCM between 1975 and 1993 at our institution. The median age at diagnosis was 11 years, and the median duration of follow-up was 11.5 years. Of the eight patients, five died (the median time from initial examination to death was 1 year). All five of these patients had clinical and radiographic evidence of pulmonary venous congestion. In all patients, 2-D and M-mode echocardiography revealed atrial enlargement without ventricular dilatation or hypertrophy. The four patients who underwent detailed diastolic Doppler assessment had findings consistent with restrictive filling and increased left ventricular end-diastolic pressure: (1) short mitral deceleration time, (2) increased pulmonary vein atrial reversal velocity and duration, and (3) pulmonary vein atrial reversal duration greater than mitral A-wave duration. CONCLUSION: The prognosis for children with IRCM is poor. In this small group of patients, absence of pulmonary venous congestion most consistently predicted extended survival. A combined 2-D and Doppler echocardiographic examination provides a reliable noninvasive means of assessing the physiologic and morphologic features of IRCM in children.

Outcomes of noncardiac surgical procedures in children and adults with congenital heart disease. Mayo Perioperative Outcomes Group.

OBJECTIVE: To assess the outcomes and risk factors for morbidity associated with anesthesia and noncardiac surgical procedures in children and adults with congenital heart disease. DESIGN: We conducted a retrospective cohort study of the 6-year period from January 1987 through November 1992 at one of the Mayo-affiliated hospitals in Rochester, Minnesota. MATERIAL AND METHODS: In all children and adults 50 years of age or younger with congenital heart disease who underwent one or more noncardiac surgical or diagnostic procedures and anesthesia, we analyzed the risk factors for 30-day perioperative morbidity and mortality. RESULTS: The overall frequency of complications among the 276 patients who underwent 480 noncardiac surgical procedures and anesthesia was 5.8% (28 of 480), and only 1 patient died intraoperatively. Major risk factors univariately associated with complications for the first procedures (15 of 276 patients or 5.4%) included the presence of cyanosis (P = 0.002), current treatment for congestive heart failure (P<0.001), poor general health (P<0.001), and younger age at the time of the procedure (P = 0.027). Procedures performed on the respiratory and nervous systems also were associated with high frequencies of complications. Complications in patients undergoing ambulatory surgical procedures were infrequent (1.7%). CONCLUSION: The frequency of perioperative complications in children and adults who have congenital heart disease and undergo noncardiac surgical procedures and anesthesia is low. Patients who have pulmonary hypertension, congestive heart failure, or cyanosis and children with congenital heart disease who are younger than 2 years of age have an increased frequency of perioperative morbidity.

Biplane intraoperative transesophageal echocardiography in congenital heart disease.

OBJECTIVE: To evaluate the accuracy, value, and safety of biplane intraoperative transesophageal echocardiography (TEE) in patients with congenital cardiac malformations. DESIGN: We reviewed the results of the first 104 consecutive biplane intraoperative TEE examinations performed during the repair of congenital heart defects at the Mayo Clinic. MATERIAL AND METHODS: TEE results were analyzed for accuracy of diagnosis, effect on the surgical procedure, and associated complications. In a subjective analysis, the relative contributions and advantages of each imaging plane (transverse and longitudinal) were also assessed. RESULTS: Biplane TEE had "significant impact" on intraoperative management in 17 of 104 examinations (16.3%). Preoperative TEE altered the planned procedure in 11 patients (10.6%). Postbypass biplane TEE led to immediate revision of the initial repair in nine patients (8.7%). Patients who underwent modified Fontan operations or subaortic resections had the greatest frequency of significant impact (40% [P = 0.006] and 33% [P = 0.03], respectively). No major complications were associated with TEE. For a complete examination, use of both imaging planes was necessary in all the patients studied. CONCLUSION: Biplane TEE is an accurate, valuable, and safe addition to the perioperative care of patients with congenital heart disease. Although intraoperative TEE is not needed in all operations for congenital heart disease, we recommend that biplane intraoperative TEE be performed routinely during modified Fontan procedures, subaortic resections, and other intracardiac operations for complex congenital cardiac malformations.

Diastolic ventricular function in children: a Doppler echocardiographic study establishing normal values and predictors of increased ventricular end-diastolic pressure.

OBJECTIVE: To extend noninvasive assessment of diastolic cardiac function into the pediatric age-group. DESIGN: This study was divided into two phases, the first of which was designed to provide an age-appropriate set of normal diastolic Doppler echocardiographic data for children and adolescents and the second of which was to determine whether these Doppler techniques could be used to identify children with increased ventricular end-diastolic pressure (EDP). MATERIAL AND METHODS: Complete echocardiographic studies focusing on Doppler variables of diastolic ventricular function were performed on 223 normal children. Values observed were analyzed for dependence on age, heart rate, and gender. Results from the normal group were then compared with Doppler values observed in a group of 24 children with catheterization-substantiated increases in ventricular EDP. RESULTS: Normal values for the Doppler factors studied vary with both age and heart rate. The variables that most confidently distinguished children with increased EDP from normal subjects were the ratio of and the difference between the durations of pulmonary vein atrial reversal and the mitral A wave. A ratio of 1.2 or more or a difference of 29 ms or more identified those children with increased EDP with sensitivities of 88 and 90% and specificities of 86 and 86%, respectively. CONCLUSION: Use of the normal data and the Doppler techniques described in this study will allow confident assessment of diastolic function in children as well as in adults.

Subaortic obstruction in hearts with a univentricular connection to a dominant left ventricle and an anterior subaortic outlet chamber. Results of a staged approach.

In 1984 we reported a 56% mortality after major cardiac operations for patients with univentricular connection to a dominant left ventricle, an anterior subaortic outlet chamber, and subaortic obstruction. Since then we have adopted a staged approach to this repair. Between 1984 and 1989 32 patients had such operations. The overall mortality has decreased (16%; p < 0.001). The current cohort was divided by subaortic gradient into three subgroups for comparison with the cohort reported in 1984. Staging improved the outcome in patients with gradients greater than 40 mm Hg (mortality of 17% compared with 67% from 1984; p = 0.05). Patients with gradients from 10 to 25 mm Hg who had a single-stage operation had the best outcome (mortality 6%). Survival has improved. Many factors, including increased awareness of the detrimental effects of subaortic obstruction, improved surgical techniques, better perioperative care, and the appropriate application of a staged repair, have contributed to this improvement. We recommend simultaneous relief of obstruction and a modified Fontan operation for patients with subaortic gradients less than 25 mm Hg. Those with gradients greater than 40 mm Hg should have repair in two stages. It is unclear whether a one-stage or two-stage approach is better for patients with gradients between these extremes.

Late results of bioprosthetic tricuspid valve replacement in Ebstein's anomaly.

BACKGROUND: Historically, porcine bioprosthetic valves have poor durability in pediatric patients; nearly half will require replacement within 5 years. However, our early experience with patients having Ebstein's anomaly suggests that tricuspid bioprostheses in this anomaly might have better durability. METHODS: One hundred fifty-eight patients who received a primary tricuspid bioprosthesis because of tricuspid valve anatomy unsuitable for repair between April 1972 and January 1997 were reviewed. Results were analyzed and Kaplan-Meier curves were constructed to estimate patient survival and probability of remaining free of reoperation. RESULTS: Follow-up of 149 patients (94.3%) who survived 30 days ranged up to 17.8 years (mean, 4.5 years). Ten-year survival was 92.5%+/-2.5% (SE), 129 late survivors (92.1%) were in New York Heart Association class I or II, and 93.6% were free of anticoagulation. Freedom from bioprosthesis replacement was 97.5%+/-1.9% at 5 years and 80.6%+/-7.6% at 10 and 15 years. CONCLUSIONS: Bioprosthesis durability in the tricuspid position in patients with Ebstein's anomaly compares very favorably with bioprosthesis durability in other cardiac valve positions, especially for pediatric patients, and also compares favorably with tricuspid bioprosthesis durability in patients with other diagnoses.

Optical triple sensor for measuring pH, oxygen and carbon dioxide.

A triple sensor unit consisting of opto-chemical sensors for measurement of pH, oxygen and carbon dioxide in bioreactors is presented. The pH and the CO2 sensor are based on the color change of a pH-sensitive dye immobilized on a polymeric support. The resulting changes in absorption are monitored through optical fibers. The oxygen sensor is based on the quenching of the fluorescence of a metal-organic dye. All three sensors are fully LED compatible. The sensitive membranes consist of plastic films and can be stored and replaced conveniently. The sensors are sterilizable with hydrogen peroxide and ethanol. In addition, the pH sensor is steam sterilizable. Accuracy, resolution and reproducibility fulfill the requirements for use in biotechnological applications. Calibration procedures for each sensor are presented. The working principle and the performance of all three sensors are described, with particular emphasis given to their application in bioreactors.