The myocardial performance index during low-dose dobutamine echocardiography in control subjects and patients with a recent myocardial infarction: a new index of left ventricular functional reserve?

BACKGROUND: Wall-motion analysis during low-dose dobutamine echocardiography (LDDE) is a semiquantitative measure of left ventricular contractile reserve after myocardial infarction (MI). The Doppler echocardiographic myocardial performance index (MPI) is a quantitative measure of combined left ventricular systolic and diastolic function. We sought to characterize the changes in MPI during LDDE in control subjects and patients with MI, and to describe the relation of these changes to changes in regional systolic function. METHODS: MPI was obtained at rest and during LDDE (10 microg/kg/min) in 25 healthy volunteers (group 1) and 50 patients with a recent MI. Patients were divided into two subsets; those with (n = 23; group 2A) and those without (n = 27; group 2B) a contractile reserve defined as an improvement of wall motion in more than two contiguous infarct-zone segments during LDDE. DeltaMPI was defined as the change from rest to LDDE. RESULTS: MPI decreased significantly during LDDE in groups 1 and 2A, whereas MPI increased in group 2B (DeltaMPI = 0.12 +/- 0.04 and 0.10 +/- 0.08 vs -0.03 +/- 0.08, P <.0001). On multivariate analysis, Deltawall-motion score index predicted DeltaMPI (beta = 0.65, P <.0001) independently of age, sex, and the dobutamine-induced change in heart rate and systolic blood pressure. CONCLUSIONS: Data suggest that the change in MPI during LDDE may provide a simple and quantitative measure of overall left ventricular functional reserve in patients with a recent MI.     

Laparoscopic Versus Open Renal Procurement for Pediatric Recipients of Living Donor Renal Transplantation

Despite reports demonstrating the safety of laparoscopic donor nephrectomy (LDN) for pediatric recipients of renal transplants, recent evidence has challenged using LDN for recipients 5 years of age or younger. We retrospectively reviewed the records of all pediatric recipients of living donor renal transplants from September 2000 through August 2004. We compared those who received allografts recovered by LDN (n = 34) with those recovered by open donor nephrectomy (ODN, n = 26). Outcomes of interest included operative complications, postoperative renal function, the incidence of delayed graft function or episodes of acute rejection and long-term graft function. Donor and recipient demographic data were similar for the LDN and ODN groups. Serum creatinine and calculated creatinine clearance were not significantly different between groups both in the early postoperative period and at long-term follow-up (p > 0.142). Rates of delayed graft function and acute rejection did not differ between groups. Among recipients aged 5 years old or younger stratified by donor technique (9 LDN, 5 ODN recipients), no difference was noted in graft outcomes both early and long-term (p > 0.079). At our center, pediatric LDN recipients have graft outcomes comparable to those of ODN recipients. At experienced centers, we recommend continued use of LDN for pediatric recipients of all ages.     

Dynamics of saccadic adaptation: differences between athletes and nonathletes.

PURPOSE: The aim of the study was to delineate differences in saccadic adaptation characteristics between a population of racquet sports athletes and nonathletes. METHODS: Eye movements were recorded at 120 Hz using a video-based eye tracker (ELMAR 2020) in a sample of 27 athletes (varsity badminton and squash players) and 14 nonathletes (<3 hours/week participation in recreational sports). Responses to negative positional error and positive positional error were studied in two sessions on separate days. Negative positional errors were induced by displacing the stimuli backwards by 3 degrees from the initial target step (12 degrees). Likewise, positive positional errors were induced by displacing the stimuli forward by 3 degrees . Amplitude gains were calculated for trials before, during, and after the adaptation phase. The magnitude and the rate of change of saccadic adaptation were determined from the amplitude gains. Differences between the groups were compared using regression analysis. RESULTS: No significant differences were found between the two groups in the magnitude of saccadic adaptation, both for negative (athletes -60%, nonathletes -57%) and positive (athletes +26%, and nonathletes +27%) positional error. Racquet sports athletes showed a significantly faster rate of adaptation for the positive positional error. A significant difference was not observed in the rate of adaptation for the negative positional error. CONCLUSIONS: Racquet sports athletes and nonathletes adapt to positional error signals by similar amounts. However, racquet sports athletes respond to positive positional errors at a faster rate, suggesting that a strategic component or environmental influences (such as practice) may play a role in saccadic adaptation.     

Does gravidity influence the success of in vitro fertilization-embryo transfer cycles?

OBJECTIVE: To evaluate the influence of gravidity on the results of in vitro fertilization (IVF)-embryo transfer (ET) cycles. PATIENTS AND METHODS: All consecutive women aged <35 years admitted to our IVF unit from January 2002 to December 2004 were enrolled in the study. Only patients undergoing one of their first three IVF cycle attempts were included. Gravidity, ovarian stimulation characteristics, number of oocytes retrieved, number of embryo transferred and clinical pregnancy rate were assessed. RESULTS: Three hundred and forty-two consecutive IVF cycles were evaluated. One hundred and sixty-one cycles were from nulligravidas and 181 from women with a history of at least one previous clinical pregnancy. Forty-eight (29.8%) clinical pregnancies were observed in the nulligravida group and 56 (30.9%) in the gravida group. There were no differences between nulligravidas and gravidas in causes of infertility, length of ovarian stimulation, peak estradiol and progesterone levels, number of oocytes retrieved, fertilization rate and number of embryos transferred. Gravidas were significantly older (30.4 vs. 27.6 years, p < 0.001) and used more gonadotropin ampoules (36.1 vs. 31.8, p < 0.004) compared with the nulligravidas. CONCLUSIONS: Patient gravidity has no influence on the likelihood of achieving pregnancy in IVF-ET cycles.     

Biological markers as indicators of exposure and pneumoconiotic risk: Prospective study

This research is designed to evaluate a number of biological markers to estimate harmful exposure on coal miners from different mining regions in France and to relate the outcome to differences in prevalence of coal worker pneumoconiosis (CWP) between these regions. Eight epidemiological groups of active and ex-miners (smokers and non-smokers) have been selected in the French collieries (North, Lorraine and Provence) according to their occupational and pneumoconiotic status. The following biomarkers have been evaluated: cellularity of sputum, elementary analysis of particles in TEM/EDAX, plasma neutral metalloendo peptidase elastase type (NMEP), leucocyte elastase (HLE), fibronectin (FN) and elastin peptides. Pulmonary alveolitis, expressed by sputum cellularity, is different between active workers groups but not related to the general background of pneumoconiosis prevalence in the French collieries. In the plasma parameters, fibronectin, HLE and NMEP significantly increased in all groups of coal mine workers as compared to the control group, except for fibronectin parameter in Lorraine collierie. The degree of increase of these parameters allow us to discriminate the different groups and suggest that plasma FN, HLE and NMEP may be considered as biological markers of chronic inhalation of coal mine dust particles. The decrease of elastin peptides level in the Lorraine group alone suggests a specific alteration of elastin metabolism. These parameters were not related to the development of pneumoconiosis and its degree of severity.     

Fresh and cultured human lens epithelial cells: an electrophysiological study of cell coupling and membrane properties

Microelectrode studies of fresh human and rabbit lens epithelia revealed stable membrane potentials [VR (human) = -36 mV; VR (rabbit) = -45 mV] and low input resistances [Ri (human) = 10 M omega; Ri (rabbit) = 20 M omega]. Coupling studies, using two voltage microelectrodes, demonstrated that the low input resistance of the fresh epithelial tissue was due to electrotonic coupling, which was found to be extremely labile and sensitive to perfusion of the apical (fibrefacing) surface of the epithelium. The intercellular coupling could be stabilized by raising the calcium concentration of the perfusate. Studies performed on confluent monolayers of cultured human lens epithelial (HLE) cells demonstrated a membrane potential (VR = -33 mV) and input resistance (Ri = 29 M omega) similar to their fresh counterparts. The intercellular coupling of these cells was found to be much more robust. Ultrastructural studies revealed that the apical junction of cultured HLE cells was less complex than that found in fresh tissue, the latter exhibiting multiple interdigitations and folds. The cultured monolayer was dissociated into single cells by a variety of methods and the membrane properties of individual cells were studied. Single cells were found to have a lower membrane potential (-20 to -25 mV) and an input resistance in the range 110-170 M omega, depending on the method of dissociation. Channel blocking and ion replacement studies revealed significant conductance pathways for potassium, sodium and chloride and a cell-attached patch clamp investigation revealed three distinct channel types. Of the two channels with inward currents at the resting potential, one, with a conductance of 25 pS, is identified as a non-selective cation channel, and the other, with a conductance of 14 pS and reversal potential of - 14 mV, is a possible candidate for a chloride channel but has yet to be characterized. A third channel with an outward current at the resting potential is identified as a potassium channel with a conductance of 49 pS. A link between epithelial uncoupling and certain types of cataract is proposed.     

An outbreak of Salmonella dublin infection in England and Wales associated with a soft unpasteurized cows' milk cheese.

An outbreak of Salmonella dublin infection occurred in England and Wales in October to December 1989. Forty-two people were affected, mainly adults, and most lived in south-east England. Microbiological and epidemiological investigations implicated an imported Irish soft unpasteurized cows' milk cheese as the vehicle of infection. A case-control study showed a statistically significant association between infection and consumption of the suspect cheese (p = 0.001). Salmonella dublin was subsequently isolated from cheeses obtained from the manufacturer's premises. Initial control measures included the withdrawal of the cheese from retail sale and a Food Hazard Warning to Environmental Health Departments, as well as a press release, from the Department of Health. Subsequently, a decision was taken by the manufacturer to pasteurize milk used in the production of cheese for the UK market and importation of the cheese resumed in June 1990.     

Cluster headache: phospholipid metabolism in polymorphonuclear cells

Our group has previously reported significant changes in the incorporation of precursors into glycerophospholipids, particularly phosphatidylserine, in polymorphonuclear cells obtained from the peripheral blood of cluster headache patients, when compared with controls. The potential of these results led to further work using both the previous methodology and a modified isolation technique to obtain polymorphonuclear cells in as pure a state as possible. Neither the new results obtained using the original technique, nor the results with high purity polymorphonuclear cells from controls and cluster headache patients, confirm the marked changes in precursor uptake into glycerophospholipids originally reported.