The effect of probiotics on respiratory infections and gastrointestinal symptoms during training in marathon runners

Heavy exercise is associated with an increased risk of upper respiratory tract infections. Strenuous exercise also causes gastrointestinal (GI) symptoms. In previous studies probiotics have reduced respiratory tract infections and GI symptoms in general populations including children, adults, and the elderly. These questions have not been studied in athletes before. The purpose of this study was to investigate the effect of probiotics on the number of healthy days, respiratory infections, and GI-symptom episodes in marathon runners in the summer. Marathon runners (N = 141) were recruited for a randomized, double-blind intervention study during which they received Lactobacillus rhamnosus GG (LGG) or placebo for a 3-mo training period. At the end of the training period the subjects took part in a marathon race, after which they were followed up for 2 wk. The mean number of healthy days was 79.0 in the LGG group and 73.4 in the placebo group (P = 0.82). There were no differences in the number of respiratory infections or GI-symptom episodes. The duration of GI-symptom episodes in the LGG group was 2.9 vs. 4.3 d in the placebo group during the training period (P = 0.35) and 1.0 vs. 2.3 d, respectively, during the 2 wk after the marathon (P = 0.046). LGG had no effect on the incidence of respiratory infections or GI-symptom episodes in marathon runners, but it seemed to shorten the duration of GI-symptom episodes.     

G protein-coupled receptor 30 is critical for a progestin-induced growth inhibition in MCF-7 breast cancer cells

The issue of how progesterone affects mammary gland growth is controversial, and the mechanism governing the effects of the hormone remains mostly unknown. We have previously shown that G protein-coupled receptor 30 (GPR30) is a progestin target gene whose expression correlates with progestin-induced growth inhibition in breast cancer cells. In this study, we investigate the role of GPR30 in regulating cell proliferation and mediating progestin-induced growth inhibition. When progestin failed to inhibit the growth of MCF-7 cells and instead stimulated growth, GPR30 was down-regulated. In this way, the inhibitory or stimulatory affects that progestin has on proliferation correlated with the level of expression of GPR30. Transient expression of GPR30 resulted in a marked inhibition of cell proliferation independent of estrogen treatment. GPR30 antisense was used to evaluate the role of GPR30 expression in progestin-induced growth inhibition. A diminished GPR30 mRNA expression by the antisense stimulated growth. Interestingly, GPR30 antisense abrogated the growth inhibitory effect of progestin and progesterone. Indeed, progestin induced 1) a reduction in cell proliferation, 2) G1-phase arrest, and 3) down-regulation of cyclin D1 was diminished. These data suggest that the orphan receptor, GPR30, is important for the inhibitory effect of progestin on growth.     

Adenosine in Myocardial Protection given through Three Windows of Opportunity. An Experimental Study with Pigs

Objective –Adenosine (ADO) has been shown to have beneficial effects against tissue injury after myocardial ischemia. However, the timing and dose of ADO administration have not been defined. This study was designed to determine the cardioprotective effect of exogenous ADO in an experimental open heart surgery model in pigs. Design –The animals were openly divided into two groups both undergoing 30 min of total cardiac arrest. In the control group animals received cold crystalloid cardioplegic solution. In the ADO group ADO was added to cardioplegic solution and in addition ADO was infused to the superior vena cava for 2 h starting 30 min before cardiac arrest. The pumping function of the heart was measured with echocardiography and myocardial blood flow was measured with microspheres and positron emission tomography (PET). Cardiomyocyte apoptosis was detected and tumor necrosis factor (TNF) levels were measured. Results –Better post-ischemic pumping function was found in the ADO group (relative decrease 43.7% vs 55.4%, p = 0.20 between the groups). The cardiac output decreased significantly from the baseline values ( p < 0.05 in both groups). There was a temporary decrease in myocardial blood flow post-ischemically, followed by a compensatory increase during the later reperfusion period. The cardiomyocyte apoptosis was induced significantly in both groups. Conclusions –In this experiment two important details were noticed. Firstly, cardiomyocyte apoptosis is involved in ischemia-reperfusion injury associated with open heart surgery. Secondly, PET is a comparable method with the microsphere technique when coronary flow is studied. No significant effects of ADO against ischemia-reperfusion injury could be shown. However, there were some signs of positive outcome, even though statistical significance could not be reached.     

Human working memory for shapes of radial frequency patterns

We investigated the human working memory for contour shapes. The memory items were radial frequency patterns (Wilkinson, Wilson, & Habak, 1998), which require global pooling of local contour orientation at the ‘intermediate’ levels of visual system. We used change-detection paradigm and d′ measure to determine the forgetting of a single pattern as a function of a retention interval, and the storage capacity for several simultaneously presented patterns. Results showed that the memory trace of a single shape is not so robust as the representations of simple features. Further, the working memory capacity for contour shapes was very low: just one item could be retained accurately.     

Pregnancy and delivery after conization of the cervix

Of 327 patients who had undergone conization of the cervix in 1968-74 in the Department of Obstetrics and Gynecology, Turku University Central Hospital, 249 replied to a questionnaire. Eighty-nine of these had had total of 112 pregnancies after conization. Conization had only minimal influence on the pregnancies and none on the deliveries. Over 90 per cent of the newborns delivered were full term and without anomalies. The incidence of spontaneous abortions also did not differ from normal.     

The effects of -cycloserine and MK-801 on the performance of rats in two spatial learning and memory tasks

The present study was undertaken to investigate the effects of modulation of the (NMDA) receptor on learning and memory. Thus, the performance of rats treated with -cycloserine, a partial agonist at the glycine recognition site of the NMDA receptor complex, and MK-801, a noncompetitive NMDA receptor antagonist, either alone or concurrently were assessed in radial arm maze and water maze tasks. Administration of MK-801 (0.1 mg/kg, i.p.) impaired acquisition in the water maze (increased escape latency and distance) and working memory in the radial arm maze (increased re-entries) in rats. Moreover, in the radial arm maze, MK-801 disrupted locomotion (increased latencies and decreased arm entries per minute) and impaired the acquisition of reference memory (increased number of errors) performance of rats. -Cycloserine (0.03, 0.3, 1.0, 3.0, 10 mg/kg, i.p.) had no effects on acquisition or memory performance of control or MK-801-treated rats in either of these tasks. However, -cycloserine (0.03, 0.3, 3.0 mg/kg) reversed the MK-801-induced disruption in locomotion. Furthermore, 3.0 mg/kg -cycloserine increased behavioral activity and also decreased the time needed to complete the task in control animals. To conclude, our results suggest that the consequences of NMDA receptor modulation on learning and memory processes and sensorimotor functions may be functionally different or have distinct anatomical locations.     

Monitoring of left ventricular ejection fraction with a miniature, nonimaging nuclear detector: Accuracy and reliability over time with special reference to blood labeling

Background

The purpose of this study was to determine the accuracy of determinations of left ventricular ejection fraction (LVEF) by a nonimaging miniature nuclear detector system (Cardioscint) and to evaluate the feasibility of long-term LVEF monitoring in patients admitted to the coronary care unit, with special reference to the blood-labeling technique.

Methods and Results

Cardioscint LVEF values were compared with measurements of LVEF by conventional gamma camera radionuclide ventriculography in 33 patients with a wide range of LVEF values. In 21 of the 33 patients, long-term monitoring was carried out for 1 to 4 hours (mean 186 minutes), with three different kits: one for in vivo and two for in vitro red blood cell labeling. The stability of the labeling was assessed by determination of the activity of blood samples taken during the first 24 hours after blood labeling. The agreement between Cardioscint LVEF and gamma camera LVEF was good with automatic background correction (r=0.82; regression equation y=1.04x+3.88) but poor with manual background correction (r=0.50; y=0.88x?0.55). The agreement was highest in patients without wall motion abnormalities. The long-term monitoring showed no difference between morning and afternoon Cardioscint LVEF values. Short-lasting fluctuations in LVEFs greater than 10EF units were observed in the majority of the patients. After 24 hours, the mean reduction in the physical decay-corrected count rate of the blood samples was most pronounced for the two in vitro blood-labeling kits (57%±9% and 41%±3%) and less for the in vivo blood-labeling kit (32%±26%). This “biologic decay” had a marked influence on the Cardioscint monitoring results, demanding frequent background correction.

Conclusion

A fairly accurate estimate of LVEF cn be obtained with the nonimaging Cardioscint system, and continuous bedside LVEF monitoring can proceed for hours with little inconvenience to the patients. Instability of the red blood cell labeling during long-term monitoring necessitates frequent background correction.     

Long-term maintenance of human articular cartilage in culture for biomaterial testing

Cartilage is a tissue that derives its unique mechanical and biological properties from the combination of relatively few cells and a large amount of a complex extracellular matrix. Furthermore, cartilage tissue is comparatively slow to respond to changes or harmful influences. To date, the optimal generation and long-term maintenance of cultured human articular cartilage for in vitro testing of biomaterials, poses an experimental difficulty. Experiments using cultured isolated chondrocytes in combination with scaffolds often fail to yield results comparable to the in-vivo situation. Consequently, our aim was to develop a culture method that allows in vitro maintenance of human hyaline cartilage explants in an optimal quality over an extended period of time. Such a culture could, for example, be used to determine the long-term effect of a new scaffold on intact cartilage, as an in vitro model for repair processes and to investigate biomaterial integration. In this study we compared conventional static cultures with and without serum supplementation to a serum-free perfusion culture for the ability to maintain human articular cartilage explants in a morphologically intact and differentiated state over an extended period of time of up to 56 days. Results were evaluated and compared by morphological, histochemical and immunohistochemical methods. The experiments showed that short-term maintenance of cartilage in a differentiated state for up to 14 days is possible under all culture conditions tested. However, best long-term culture results for up to 56 days were obtained with perfusion culture under serum-free conditions. Such a perfusion culture system can be used to perform biocompatabilty tests in vitro by long-term coculture of biomaterial and intact human articular cartilage.     

Hormonal responses to daily strenuous walking during 4 successive days

The hormonal response to 4 days' walking exercise (totaling 164 km) was examined among 15 healthy males. We hypothesised that submaximal daily, repeated, prolonged exercise may disturb the balance of the adrenal cortex and pituitary–testicular axis, which could be analysed from the concentrations of serum cortisol and testosterone, and with time-resolved immunofluorometric assay (IFMA) of luteinising hormone (LH) and follicle stimulating hormone (FSH). In the adrenal cortex the increased response to acute exercise could be seen after the 1st day. The concentration of testosterone was reduced after the first two exercise sessions and a plateau was reached after the 3rd day of walking. LH decreased during the 2nd and 3rd day by 31% (P=0.04 and 0.001, respectively) and remained steady on the 4th day. In FSH the suppression was seen all the time after the second exercise session and before the final walk it was reduced by 19% (P=0.02) compared with the baseline. The acute response of the adrenal cortex and pituitary–gonadal axis (excluding secretion of FSH) disappeared within 4 days of repeated prolonged walking and no dramatic lasting changes occurred despite this major 4-day effort. However, when using the sensitive IFMA, which can detect low concentrations of gonadotropins, secretion of FSH was seen to remain reduced and no stability was seen. Electronic Publication