Aortic and mitral valve replacement with reconstruction of the intervalvular fibrous body

AbstractObjective: The intervalvular fibrous body between the aortic and mitral valves can be damaged by infective endocarditis, degenerative calcification, or multiple previous heart valve operations, making double valve replacement difficult. We have managed this problem by approaching the aortic and mitral valves through the aortic root and the dome of the left atrium. After excising the aortic valve, the diseased fibrous body, and the mitral valve, we suture a properly tailored patch of Dacron fabric or bovine pericardium to the lateral and medial fibrous trigones and to the aortic root, reestablishing the aortic and mitral anuli. A prosthetic mitral valve is implanted and a separate patch is used to close the left atriotomy before implantation of a prosthetic aortic valve. This study was undertaken to determine the efficacy of this operation. Methods: Forty-three patients underwent reconstruction of the intervalvular fibrous body during aortic and mitral valve replacement because of infective endocarditis with abscess in 14 patients, extensive calcification in 9, lack of fibrous tissue because of multiple previous operations in 10, and to enlarge the aortic and mitral anuli in 10. The group comprised 18 men and 25 women with a mean age of 58 ± 12 years. Thirty-two patients had had one or more previous heart valve replacements. All patients were in New York Heart Association functional classes III and IV, and 9 patients were in shock before the operation. Results: Seven operative deaths occurred (16%). Early prosthetic valve endocarditis developed in two patients and necessitated reoperation. Follow-up extended from 4 to 108 months, with a mean of 38 months. No patient was lost to follow-up. Six late deaths occurred. The actuarial survival at 6 years was 56% ± 6%. A Doppler echocardiographic study revealed normal prosthetic valve function and anatomically intact anuli in all 30 long-term survivors. Conclusions: Reconstruction of the intervalvular fibrous body during aortic and mitral valve replacement is a satisfactory operative approach in patients with complex valve annular pathology. (J Thorac Cardiovasc Surg 1997;114:766-72

Nutri One-on-One: Improving Patients’ Metabolic Profile with One-on-One Nutritional Coaching

Introduction: More than one-third of U.S. adults (35.7%) are obese. Some of the leading causes of death are due to complications of chronic conditions related to metabolic disorders and obesity. One on one health coaching will assist people in adopting healthy lifestyle behaviors that prevent and control diseases through phases of effective goal setting, motivational interviewing, and collaboration with health care providers. Objectives: This study’s aim was to positively influence patients’ nutritional habits and lifestyle through a brief one on one coaching session. The effects of one on one nutritional education are analyzed through goal setting, motivational lessons, and follow-up to improve lifestyle. Methodology: Patients were interviewed to gain insight into their daily nutritional routines and patients’ anthropometric histories were obtained. Patients were then encouraged to set a primary health goal. A personalized nutritional lesson was administered to address the health goal and current nutritional behaviors. The patient and health coach then arrived at three simple and obtainable lifestyle modifications to reach the initial goal. Obstacles were addressed and a follow-up phone call was scheduled to obtain self-reported results and insure accountability and support. Results: The study included 57 adult patients (39 female, 18 male) with metabolic disorders and demonstrated an overwhelming success with nutritional fact recollection, progress on the readiness scale, goal achievement, and in office experience satisfaction. A majority of patients showed willingness and motivation to continue implementing a healthy lifestyle. Conclusion: Personalized one on one nutritional coaching tailored to patient’s goal proved to be successful. Tailored education on healthy living, nutrition, and motivational techniques continued to create positive behavior modification. The follow-up sessions provided reinforcement in sustaining success

A manned exobiology laboratory based on the Moon

Establishment of an exobiology laboratory on the Moon would provide a unique opportunity for exploration of extraterrestrial materials on a long-term, ongoing basis, for elucidation of exobiological processes and chemical evolution. A major function of the lunar exobiology laboratory would be to examine samples collected from other planets (e.g., Mars) for the presence of extant or extinct life. By establishing a laboratory on the Moon, preliminary analyses could be conducted away from Earth, thus establishing that extraterrestrial materials are benign before their return to Earth for more extensive investigations. The Moon-based exobiology laboratory would have three major components for study of samples returned from other planets: (1) the search for extant life - this component would focus on the detection and identification of life forms using biological, physical, and chemical methods; (2) the search for extinct life - this component would concentrate on identification of extinct life using micropaleontological physical and chemical means; and (3) the search and evidence of chemical evolution - this component would be devoted to the detection and identification of molecules revealing prebiotic chemical evolution

Targeted DNA demethylation of the Arabidopsis genome using the human TET1 catalytic domain.

DNA methylation is an important epigenetic modification involved in gene regulation and transposable element silencing. Changes in DNA methylation can be heritable and, thus, can lead to the formation of stable epialleles. A well-characterized example of a stable epiallele in plants is fwa, which consists of the loss of DNA cytosine methylation (5mC) in the promoter of the FLOWERING WAGENINGEN (FWA) gene, causing up-regulation of FWA and a heritable late-flowering phenotype. Here we demonstrate that a fusion between the catalytic domain of the human demethylase TEN-ELEVEN TRANSLOCATION1 (TET1cd) and an artificial zinc finger (ZF) designed to target the FWA promoter can cause highly efficient targeted demethylation, FWA up-regulation, and a heritable late-flowering phenotype. Additional ZF-TET1cd fusions designed to target methylated regions of the CACTA1 transposon also caused targeted demethylation and changes in expression. Finally, we have developed a CRISPR/dCas9-based targeted demethylation system using the TET1cd and a modified SunTag system. Similar to the ZF-TET1cd fusions, the SunTag-TET1cd system is able to target demethylation and activate gene expression when directed to the FWA or CACTA1 loci. Our study provides tools for targeted removal of 5mC at specific loci in the genome with high specificity and minimal off-target effects. These tools provide the opportunity to develop new epialleles for traits of interest, and to reactivate expression of previously silenced genes, transgenes, or transposons

Sequence heterogeneity and the dynamics of molecular motors

The effect of sequence heterogeneity on the dynamics of molecular motors is reviewed and analyzed using a set of recently introduced lattice models. First, we review results for the influence of heterogenous tracks such as a single-strand of DNA or RNA on the dynamics of the motors. We stress how the predicted behavior might be observed experimentally in anomalous drift and diffusion of motors over a wide range of parameters near the stall force and discuss the extreme limit of strongly biased motors with one-way hopping. We then consider the dynamics in an environment containing a variety of different fuels which supply chemical energy for the motor motion, either on a heterogeneous or on a periodic track. The results for motion along a periodic track are relevant to kinesin motors in a solution with a mixture of different nucleotide triphosphate fuel sources.Comment: To appear in a JPhys special issue on molecular motor

Solar Neutrinos with Three Flavor Mixings

The recent 71Ga solar neutrino observation is combined with the 37Cl and Kamiokande-II observations in an analysis for neutrino masses and mixings. The allowed parameter region is found for matter enhanced mixings among all three neutrino flavors. Distortions of the solar neutrino spectrum unique to three flavors are possible and may be observed in continuing and next generation experiments.Comment: August 1992 (Revised) PURD-TH-92-

Incidence, prevalence, and clinical course of hepatitis C following liver transplantation

Hepatitis C virus (HCV) is the agent responsible for posttransfusion hepatitis. The incidence, timing, and clinical course of HCV positive hepatitis in liver transplant recipients are unknown. Three hundred and seventeen donor-recipient liver transplant pairs were grouped on the basis of their pretransplant HCV antibody status. The biopsy findings were examined. Four distinct groups were identified on the basis of HCV serology: group I, both were negative; group II, donor was negative and recipient was positive; group III, donor was positive and recipient was negative; group IV, both were positive. The prevalence of anti-HCV positivity in recipients was 13.6%. The rate of seroconversion was 9.2%. Histologic hepatitis not ascribable to any specific cause other than non-A, non-B (NANB) hepatitis occurred in 13.8%. The incidence of histologic chronic active hepatitis was 1.6%, and none progressed to cirrhosis. The concordance rate for a positive anti-HCV serology and NANB hepatitis was 2.8%. Of the 35 patients (group II and IV) with positive anti-HCV serology pretransplant, only 17 were positive posttransplantation. Based on these data it can be concluded that posttransplant NANB hepatitis occurred in 13.8% of liver recipients. Twenty percent of these were anti-HCV positive. Progression to histologic chronic active hepatitis occurs over a period of 1-5 years in 1.6% of cases. © 1992

Automated rating of patient and physician emotion in primary care visits

OBJECTIVE: Train machine learning models that automatically predict emotional valence of patient and physician in primary care visits. METHODS: Using transcripts from 353 primary care office visits with 350 patients and 84 physicians (Cook, 2002 [1], Tai-Seale et al., 2015 [2]), we developed two machine learning models (a recurrent neural network with a hierarchical structure and a logistic regression classifier) to recognize the emotional valence (positive, negative, neutral) (Posner et al., 2005 [3]) of each utterance. We examined the agreement of human-generated ratings of emotional valence with machine learning model ratings of emotion. RESULTS: The agreement of emotion ratings from the recurrent neural network model with human ratings was comparable to that of human-human inter-rater agreement. The weighted-average of the correlation coefficients for the recurrent neural network model with human raters was 0.60, and the human rater agreement was also 0.60. CONCLUSIONS: The recurrent neural network model predicted the emotional valence of patients and physicians in primary care visits with similar reliability as human raters. PRACTICE IMPLICATIONS: As the first machine learning-based evaluation of emotion recognition in primary care visit conversations, our work provides valuable baselines for future applications that might help monitor patient emotional signals, supporting physicians in empathic communication, or examining the role of emotion in patient-centered care