Response of left ventricular diastolic filling to graded exercise relative to the lactate threshold

Summary During incremental exercise, the left ventricular ejection fraction increases up to the intensity of the anaerobic threshold and tends to level off at higher exercise intensities. Since there is a correlation between the response of peak filling rate and ejection fraction to exercise, this study was conducted to determine whether the response of left ventricular diastolic function is similar to the response of systolic function relative to lactate threshold. Twelve healthy men performed two exercise tests on a cycle ergometer. In the first test, lactate threshold and maximal power output were determined. In the second exercise test, gated radionuclide ventriculography was performed at rest, at the lactate threshold intensity, and at peak exercise to measure ejection fraction and peak filling rate. Ejection fraction increased significantly from rest [mean (SD): 62 (5)%] to lactate threshold [76 (7) %] and did not change significantly from lactate threshold to peak exercise [77 (7)%]. Likewise, peak filling rate (normalized for stroke counts) increased from resting [6.1 (0.9)V _s · s^–1] to lactate threshold [9.4 (1.8)V _s · s^–1] and did not change significantly from lactate threshold to peak exercise [9.6 (2.9)V _s · s^–1]. There was no correlation between the change in peak filling rate and the change in ejection fraction from rest to lactate threshold. Thus, during incremental exercise, left ventricular diastolic function responds qualitatively similar to systolic function.     

Wasting during pregnancy increases the risk of mother-to-child HIV-1 transmission

OBJECTIVES: To examine whether wasting during pregnancy, as measured by weight loss and low weight gain, is associated with increased mother-to-child transmission (MTCT) of HIV-1. METHODS: This was a cohort study in Dar es Salaam, Tanzania, among 957 HIV-1-infected pregnant women. Weight was measured at the first prenatal visit and every month thereafter until delivery. Weight loss was defined as a weekly rate of weight gain 0 and /=167 g/wk, weight loss during pregnancy was related to higher risk of intrauterine MTCT (adjusted relative risk [RR] = 2.32, 95% CI = 1.23-4.36, P = 0.009), HIV positive at birth or fetal death (RR = 2.13, 95% CI = 1.40-3.24, P = 0.0004), and HIV positive at birth or early neonatal death (RR = 1.96, 95% CI = 1.26-3.07, P = 0.003). The rate of weight gain during the 3rd trimester was inversely related to the risk of intrapartum/early breast-feeding transmission (adjusted P value, test for trend = 0.05). CONCLUSIONS: Weight loss during pregnancy increases the risk of early MTCT. Identifying causes of wasting during pregnancy may provide clues for new strategies to prevent MTCT.     

Pointwise‐constrained optimal control of a semiactive vehicle suspension

This article presents an optimal control strategy (OCS) for semiactive vehicle suspensions with road profile sensors. The suspension is modeled as a quarter‐car model with a magnetorheological (MR) damper. The OCS main objective is to minimize the fourth‐power acceleration of the sprung mass. In addition, three pointwise constraints of the model are taken into account when the optimal control problem is solved: suspension travel limits (upper and lower) and tyre vertical force. In order to deal with a large number of constraints, we implement the gradient optimization method based on the method of moving asymptotes routine, which shows very good performance reaching optimal controls while satisfying the constrains. The solution has been compared with two passive MR damper configurations (low and high damping) as well as Skyhook and Balance control strategies for three different road inputs. Results show that OCS fulfills the constraints and reduces the sprung mass acceleration peak and the root‐mean‐quad acceleration up to 59% , in comparison to passive strategies.     

Laparoscopic pyeloplasty as an alternative to nephrectomy in adults with poorly functioning kidneys due to ureteropelvic junction obstruction

International Urology and Nephrology - To evaluate outcomes of laparoscopic pyeloplasty (LP) in adults with poorly functioning kidney due to ureteropelvic junction obstruction (UPJO). A...     

Geodemographic analysis of pediatric firearm injuries in Miami,FL

PurposeFirearm injuries (GSW) are a growing public health concern and leading cause of morbidity and mortality among children, yet predictors of injury remain understudied. This study examines the correlates of pediatric GSW within our county.MethodsWe retrospectively queried an urban Level 1 trauma center registry for pediatric (0–18 years) GSW from September 2013 to January 2019, examining demographic, clinical, and injury information. We used a geographic information system to map GSW rates and perform spatial and spatiotemporal cluster analysis to identify zip code “hot spots.”Results393 cases were identified. The cohort was 877% male, 87% African American, 10% Hispanic, and 22% Caucasian/Other. Injuries were 92% violence-related and 4% accidental, with 63% occurring outside school hours. Mortality was 12%, with 53% of deaths occurring in the resuscitation unit. Zip-level GSW rates ranged from 0 to 9 (per 1000 < 18 years) by incident address and 0–6 by home address. Statistically significant hot spots were in predominantly underserved African American and Hispanic neighborhoods.ConclusionsGeodemographic analysis of pediatric GSW injuries can be utilized to identify at-risk neighborhoods. This methodology is applicable to other metropolitan areas where targeted interventions can reduce the burden of gun violence among children.Type of studyRetrospective study.Level of evidenceLevel III.     

Surgical resection for non-Asian intrahepatic lithiasis: The Brazilian experience

BackgroundIntrahepatic lithiasis (IHL) is a rare disease in the western world. Complications associated with IHL include acute cholangitis, liver atrophy, secondary biliary cirrhosis, and risk for intrahepatic cholangiocarcinoma. Liver resection is considered the treatment of choice for IHL. The objective of this study was to analyze patients who underwent liver resection for non-Asian hepatolithiasis.Methods127 patients with symptomatic non-Asian hepatolithiasis underwent resection in six institutions. Demographic data, clinical presentation, diagnosis, classification according to stone location, presence of atrophy, bile duct stricture, biliary cirrhosis, incidence of cholangiocarcinoma, treatment and postoperative course were evaluated.Results52 patients (40.9%) were male and the mean age was 46.1 years. Sixty-six patients (51.9%) presented with history of cholangitis. Stones were located in the left lobe in 63 (49.6%), and right lobe in 28 patients (22.0%). Atrophy was observed in 31 patients (24.4%) and biliary stenosis in 18 patients (14.1%). The most common procedure performed was left lateral sectionectomy in 63 (49.6%) patients, followed by left hepatectomy in 36 (28.3%), right hepatectomy in 19 (15.0%), and associated hepaticojejunostomy in 28 (22.0%). Forty-two patients (33.0%) presented postoperative complications and the most common were biliary fistula (13.3%) and surgical site infection (7.0%). Postoperative mortality was 0.7%. Intrahepatic cholangiocarcinoma was observed in 2 patients (1.5%). Recurrence was identified in 10 patients (7.8%), mostly with bilateral stones and/or hepaticojejunostomy.ConclusionLiver resection is the standard treatment for symptomatic unilateral or complicated IHL with good operative results. Risk of cholangiocarcinoma was low in non-Asian patients.     

Liver-First Approach for Synchronous Colorectal Metastases: Analysis of 7360 Patients from the LiverMetSurvey Registry

Annals of Surgical Oncology - The liver-first approach in patients with synchronous colorectal liver metastases (CRLM) has gained wide consensus but its role is still to be clarified. We aimed to...     

Transthyretin amyloidosis with cardiomyopathy after domino liver transplantation: Results of a cross-sectional study

Domino liver transplantation (DLT) has been used widely in patients with hereditary amyloid transthyretin (ATTR) amyloidosis. New-onset polyneuropathy in recipients of DLT has been reported, but there are few cases of cardiac involvement reported. We aimed to perform a cross-sectional study for ATTR amyloidosis with cardiomyopathy (ATTR-CM) in DLT recipients. We evaluated 23 living DLT recipients a median of 9 years since DLT at 2 referral centers with a systematic cardiac evaluation, including bone scintigraphy. Median age was 72 years, 91% had hypertension, 35% had diabetes mellitus, 67% had chronic renal failure, and 8 patients (35%) developed new-onset polyneuropathy. Only 13% had a normal electrocardiogram and a normal echocardiography, and most of them showed some conduction disturbance or increase in left ventricular wall thickness, but only 1 patient with a Glu89Lys mutation developed ATTR-CM diagnosed by bone scintigraphy and endomyocardial biopsy. None of the recipients of a DLT with Val30Met mutation showed cardiac involvement by bone scintigraphy. In conclusion, DLT from Val30Met donors seems to be safe regarding the development of ATTR-CM. Evaluation of cardiomyopathy in DLT recipients is challenging due to concomitant comorbidities and in this context, bone scintigraphy can be helpful to evaluate ATTR-CM.