Dental Procedures and the Risk of Infective Endocarditis

Infective endocarditis (IE) is an uncommon but potentially devastating disease. Recently published data have revealed a significant increase in the incidence of IE following the restriction on indications for antibiotic prophylaxis as recommended by the revised guidelines. This study aims to reexamine the basic assumption behind the rationale of prophylaxis that dental procedures increase the risk of IE.Using the Longitudinal Health Insurance Database of Taiwan, we retrospectively analyzed a total of 739 patients hospitalized for IE between 1999 and 2012. A case-crossover design was conducted to compare the odds of exposure to dental procedures within 3 months preceding hospitalization with that during matched control periods when no IE developed.In the unadjusted model, the odds ratio (OR) was 0.93 for tooth extraction (95% confidence interval [CI] 0.54–1.59), 1.64 for surgery (95% CI 0.61–4.42), 0.92 for dental scaling (95% CI 0.59–1.42), 1.69 for periodontal treatment (95% CI 0.88–3.21), and 1.29 for endodontic treatment (95% CI 0.72–2.31). The association between dental procedures and the risk of IE remained insignificant after adjustment for antibiotic use, indicating that dental procedures did not increase the risk of IE.Therefore, this result may argue against the conventional assumption on which the recommended prophylaxis for IE is based.     

Hemodynamic changes in hyperthyroidism-related pulmonary hypertension: a prospective echocardiographic study

CONTEXT: Recent reports suggest an association between hyperthyroidism and pulmonary hypertension (PHT), although the potential mechanisms and clinical implications remain unclear. OBJECTIVE: Our objective was to determine the prevalence of PHT related to hyperthyroidism and the associated hemodynamic changes and outcome. METHODS AND RESULTS: We performed serial echocardiographic examinations in 75 consecutive patients with hyperthyroidism (43 +/- 2 yr, 47 women) to estimate pulmonary artery systolic pressure (PASP), cardiac output (CO), total vascular resistance (TVR), and left ventricular (LV) filling pressure. Examinations were performed at baseline and 6 months after initiation of antithyroid treatment. Results were compared with 35 age- and sex-matched healthy controls. All hyperthyroid patients had normal LV systolic function, and 35 patients (47%) had PHT with PASP of at least 35 mm Hg. There were no significant differences in the clinical characteristics of hyperthyroid patients with or without PHT (all P > 0.05). Nonetheless, those with PHT had significantly higher CO, PASP, peak transmitral early diastolic flow velocity (E), and ratio of E to early diastolic mitral annular velocity (E') compared with those without PHT and controls (all P < 0.05). Hyperthyroid patients with PHT also had significantly lower TVR than controls (P < 0.05). Among the 35 hyperthyroid patients with PHT, 25 (71%) had pulmonary arterial hypertension (PAH) with normal E/E', and 10 (29%) had pulmonary venous hypertension (PVH) with elevated E/E'. Hyperthyroid patients with PAH had a significantly higher CO and a lower TVR compared with those with PVH. In contrast, hyperthyroid patients with PVH had lower E' and a higher E/E' ratio compared with those with PAH. These hemodynamic abnormalities and PHT were reversible in patients with PAH or PVH after restoration to a euthyroid state. CONCLUSION: In patients with hyperthyroidism and normal LV systolic function, up to 47% had PHT due to either PAH with increased CO (70%) or PVH with elevated LV filling pressure (30%). Most importantly, hyperthyroidism-related PHT was largely asymptomatic and reversible after restoration to a euthyroid state.     

Distinct patterns of ALDH1A1 expression predict metastasis and poor outcome of colorectal carcinoma

Purpose: Aldehyde dehydrogenase 1A1 (ALDH1A1) has been proposed as a candidate biomarker for colorectal carcinoma (CRC). However, the heterogeneity of its expression makes it difficult to predict the outcome of CRC. The aim of this study was to evaluate the diagnostic and prognostic value of this molecule in CRC. Methods and Results: In this study, we examined ALDH1A1 expression by immunohistochemistry including 406 cases of primary CRC with corresponding adjacent mucosa, with confirmation of real-time PCR and Western blotting. We found that the expression patterns of ALDH1A1 were heterogeneous in the CRC and corresponding adjacent tissues. We defined the ratio of ALDH1A1 level in adjacent mucosa to that in tumor tissues as R_A/C and found that the capabilities of tumor invasion and metastasis in the tumors with R_A/C < 1 were significantly higher than those with R_A/C ≥ 1. Follow-up data showed the worse prognoses in the CRC patients with R_A/C < 1. For understanding the underlying mechanism, the localization of β-catenin was detected in the CRC tissues with different patterns of ALDH1A1 expression from 221 patients and β-catenin was found preferentially expressed in cell nuclei of the tumors with R_A/C < 1 and ALDH1A1^high expression of HT29 cell line, indicating that nuclear translocation of β-catenin might contribute to the increased potentials of invasion and metastasis. Conclusion: Our results indicate that R_A/C is a novel biomarker to reflect the distinct expression patterns of ALDH1A1 for predicting metastasis and prognosis of CRC.     

Evaluation of serum anti-mullerian hormone as a biomarker of early ovarian aging in young women undergoing IVF/ICSI cycle

Objective: To determine whether or not the level of serum anti-Müllerian hormone (AMH) is related to early ovarian aging in young women (< 35 years of age) undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles. Design: Retrospective cohort study. Setting: An IVF laboratory in a university hospital in Taiwan. Patient (s): 70 young women (< 35 years of age) with low level of serum AMH (< 2 ng/ml) and 104 young women with level of serum AMH (≥ 2 ng/ml) who underwent IVF/ICSI cycles between January 2011 and November 2012 were enrolled. Intervention (s): None. Main outcome measure (s): Number of oocytes, fertilization rate, embryo quality, cycle cancellation rate, clinical pregnancy/abortion rate, and perinatal/infant outcomes. Results: The clinical pregnancy rate per transfer was favorable (low AMH group vs. normal AMH group [47.2% and 47.9%]) for women < 35 years of age, including women with a low serum AMH. Similarly, the live birth rate per transfer (low AMH group vs. normal AMH group [37.7% and 35.4%]) and perinatal outcomes were also comparable between the two groups. A significantly higher cycle cancellation was noted in the low AMH group than the normal AMH group (24.2% vs. 7.6%). Conclusion: Although early ovarian aging should be taken into consideration for young and infertile women with low AMH level than expected, our results suggest that low serum AMH level may suggest early ovarian aging in accelerated oocyte loss only, but may not fully represent “early ovarian aging” based on the favorable outcomes of pregnancy.     

Can we predict pathologic complete response before surgery for locally advanced rectal cancer treated with preoperative chemoradiation therapy?

Background

Pathologic complete response has been proven to have oncological benefits for locally advanced rectal cancer treated with chemoradiation therapy. The aims of this study are to analyze and determine the factors to predict pathologic complete response for patients treated with preoperative neoadjuvant therapy.

Methods

Patients with biopsy-proven, locally advanced rectal cancer were treated neoadjuvantly followed by radical surgical resection. Tumors were re-assessed after completing chemoradiation, including pelvic magnetic resonance images, colonoscopic examination, and re-biopsy. The results of examination were compared with the final pathologic status.

Results

A retrospective chart review of 166 patients was conducted. Twenty-five patients (15.1%) had pathologic complete response after chemoradiation. The 5-year overall survival rates were better in the complete response group than the residual tumor group (91.1% vs. 70.8%; P?=?0.047), and there were also significant differences in the 5-year disease-free survival rates between these two groups (91.1% vs. 70.2%; P?=?0.027). The prediction rates for pathologic complete response by re-biopsy, magnetic resonance images, and colonoscopy were 21.4%, 33.3%, and 53.8%, respectively. In addition, when we further combine the results of colonoscopic findings and re-biopsy, the prediction rate for pathologic complete response reached 77.8% (P?=?0.009).

Conclusions

Combining the results of the re-biopsy and post-treatment colonoscopic findings, we can achieve a good prediction rate for pathologic complete response. Post-treatment magnetic resonance images are not useful tools in predicting tumor clearance following chemoradiation.     

Regenerative peripheral nerve interfaces for real-time,proportional control of a Neuroprosthetic hand

Introduction

Regenerative peripheral nerve interfaces (RPNIs) are biological constructs which amplify neural signals and have shown long-term stability in rat models. Real-time control of a neuroprosthesis in rat models has not yet been demonstrated. The purpose of this study was to: a) design and validate a system for translating electromyography (EMG) signals from an RPNI in a rat model into real-time control of a neuroprosthetic hand, and; b) use the system to demonstrate RPNI proportional neuroprosthesis control.

Methods

Animals were randomly assigned to three experimental groups: (1) Control; (2) Denervated, and; (3) RPNI. In the RPNI group, the extensor digitorum longus (EDL) muscle was dissected free, denervated, transferred to the lateral thigh and neurotized with the residual end of the transected common peroneal nerve. Rats received tactile stimuli to the hind-limb via monofilaments, and electrodes were used to record EMG. Signals were filtered, rectified and integrated using a moving sample window. Processed EMG signals (iEMG) from RPNIs were validated against Control and Denervated group outputs.

Results

Voluntary reflexive rat movements produced signaling that activated the prosthesis in both the Control and RPNI groups, but produced no activation in the Denervated group. Signal-to-Noise ratio between hind-limb movement and resting iEMG was 3.55 for Controls and 3.81 for RPNIs. Both Control and RPNI groups exhibited a logarithmic iEMG increase with increased monofilament pressure, allowing graded prosthetic hand speed control (R²?=?0.758 and R²?=?0.802, respectively).

Conclusion

EMG signals were successfully acquired from RPNIs and translated into real-time neuroprosthetic control. Signal contamination from muscles adjacent to the RPNI was minimal. RPNI constructs provided reliable proportional prosthetic hand control.