Nitrates and calcium antagonists for silent myocardial ischemia

Continuous Holter monitoring of patients with coronary heart disease can show transient ischemic episodes occurring spontaneously with or without angina throughout the day. A controlled double-blind trial was conducted comparing the effects of isosorbide-5-mononitrate (IS-5-MN) and nifedipine in patients with documented transient ischemic episodes. Seventy-five percent of the ischemic episodes were not accompanied by pain. Twenty patients with documented coronary heart disease were included; 15 finished the 4-week study (1 patient had headaches, 1 thyrotoxicosis, 1 hypertensive crisis and 2 unstable angina). On a dual-channel FM-recorded electrocardiogram, ischemic episodes were counted when ST deviation was greater than 1 mm for greater than 1 minute. Patients received IS-5-MN (20 mg 3 times a day or 50 mg in a sustained-release tablet) or nifedipine (20 mg in a sustained-release tablet 3 times a day) in random order over four 1-week periods. At the end of each week, Holter monitoring was repeated and showed reductions of episodes by 67% and 67% after weeks of IS-5-MN therapy and 56% and 58% after weeks of nifedipine therapy (all p less than 0.05). Painful and painless episodes were reduced to a similar extent. Individual responses showed great variability, and in all treatment periods not more than half of the patients were completely free of ischemic episodes. One of the 12 patients did not respond to either way of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparative right and left ventricular volumes and pump function in the newborn lamb

A quantitative cineangiographic method is presented for studying neonatal lamb ventricular volumes and pump function without thoracotomy or surgical instrumentation of the heart. When this method was employed in lambs with a mean age of 24.4 hours it was found that the right and left ventricular end-diastolic volumes, ejection fractions and systolic outputs did not differ significantly at this early postnatal time. Restudy of these lambs at a mean age of 15.6 days showed that right and left ventricular end-diastolic volumes, normalized for body weight, and ejection fractions had not changed significantly. Although systolic outputs decreased, the difference was not significant. Thus there is early postnatal equalization of left and right heart volumes, and deviations from this relation should suggest abnormal hemodynamic function.     

Dose-response analyses of associative tolerance to nicotine analgesia in the rat: tail-flick and hot-plate tests

This study is the first to demonstrate associative tolerance to nicotine's analgesic effects as a shift in the dose-response curve (DRC) to the right. The subjects were 43 experimentally naive, male Sprague Dawley rats (Rattus norvegicus) randomly assigned to 2 groups. Home cage rats (HC; n = 21) received a series of 1 mg/kg nicotine doses explicitly unpaired with the distinctive context, whereas distinctive context rats (DC; n = 22) were injected with nicotine explicitly paired with the distinctive context. Rats in each of the 2 groups were randomly assigned to 1 of 3 nicotine testing doses to construct DRCs. The DRC of the rats that received nicotine in the distinctive context was shifted to the right of the DRC of rats that had had as much exposure to nicotine but had never experienced nicotine in the distinctive context. DC rats required nearly twice as much nicotine as HC rats to produce the same DRC. The discussion describes the implications of the results for theories of drug tolerance and nicotine addiction.     

Children's sleep and adjustment: the moderating role of vagal regulation

Children's vagal tone and vagal suppression were examined as moderators of associations between children's sleep disruptions and adjustment problems. A relatively large sample (n = 167) of boys and girls who ranged in age between 8 and 9 years participated with their parents. Sleep was examined via actigraphy in the child's home for seven consecutive days. Children's vagal tone was examined during baseline conditions, and their vagal suppression was assessed in response to an inter-adult argument. In comparison with children exhibiting higher levels of vagal tone, those with lower vagal tone were at increased risk of externalizing problems, depression symptoms and higher body mass index associated with increased sleep disruptions (i.e. lower Sleep Efficiency, increased Wake Minutes and fewer Sleep Minutes). Thus, lower vagal tone functioned as a vulnerability factor for adjustment problems in the context of sleep problems. A higher level of vagal suppression to the inter-adult argument functioned as a protective factor against externalizing behaviors otherwise associated with increased Wake Minutes and reduced Sleep Efficiency. Findings demonstrating the moderating role of vagal functioning in the context of sleep disruptions are novel, and highlight the importance of individual differences in children's physiological regulation for sleep and adjustment.     

Anatomy of brain lesions after stroke predicts effectiveness of mirror therapy

To improve clinical outcome, one longstanding goal in treating stroke patients has been an individual therapy based on functional and anatomical knowledge of the single patient. Therefore, in this study brain imaging of 36 chronic stroke patients was analyzed to identify parameters predicting clinical recovery. T1‐weighted MRI was acquired to assess the lesion; functional MRI was used to visualize existing resources; DTI for the integrity of the corticospinal tract (CST) and long association tracts. These data were related to the clinical course. All patients were treated intensively with the mirror therapy (MT) only. After the training period, we analyzed which patient's feature would predict a beneficial course. Patients as a group improved after MT, but according to the fMRI activation of primary sensorimotor cortex (SMC), they could be divided in two groups with very diverging clinical outcome: those with ipsilesional SMC activation showed a noticeable increase of clinical scores, accompanied with ipsilesional activation in the frontal projection areas of the dorsal and ventral streams during action observation in fMRI. Those with contralesional SMC activation had lesions affecting both the dorsal and ventral stream and did not benefit from MT. The outcome for this therapy was not related to affection of CST. This study demonstrates that only in patients in which dorsal and ventral streams are not affected and therefore an interaction between these streams in post‐ and prerolandic regions is possible, MT can induce clinical improvement. Consequently, knowledge of the anatomical lesion can predict the beneficial course of MT.     

Endothelial cells are protected against phagocyte-transmitted Chlamydophila pneumoniae infections by laminar shear stress Gueinzius: Shear stress protects from C. pneumoniae infection

The respiratory pathogen Chlamydophila pneumoniae can be detected in atherosclerotic vessels, but the mechanism of dissemination from lung to vasculature remains unknown. Disturbance of vascular shear stress is a risk factor for atherosclerosis. We investigated whether polymorphonuclear neutrophils (PMN) might serve as carriers, transmitting C. pneumoniae to endothelial cells and how this is affected by shear stress. PMN were prepared from blood and incubated with C. pneumoniae. Real-time PCR and Pathfinder staining showed that after 1h, 20% of C. pneumoniae were ingested and started to form inclusions. When infected PMN were co-incubated with HUVEC for 96h, 10% of PMN-ingested C. pneumoniae were transmitted to HUVEC as shown by PCR and confocal microscopy. Infection of HEp-2 cells with C. pneumoniae harvested from HUVEC resulted in C. pneumoniae replication and confirmed that the bacteria remained infective. Exposure to laminar shear stress in a rotating cone-and-plate apparatus did not affect the transmission of C. pneumoniae from PMN to HUVEC, but led to a 75% reduction of inclusion formation. This can explain the focal distribution of C. pneumoniae in the vasculature and links two risk factors of atherosclerosis, i.e. the lack of laminar flow and infection.     

The association between children's sleep disruption and salivary interleukin-6

We explored relations between children's sleep and levels of salivary interleukin-6 (IL-6). Children were healthy boys (n = 28) and girls (n = 36) who ranged in age between 8 and 9 years. Through actigraphy, the amount and quality of children's sleep was examined objectively in their homes for 1 week. Children also rated their Morningness/Eveningness predisposition and subjective sleepiness, and parents reported on their children's Sleep Disordered Breathing and Sleepiness. Children provided saliva samples before and after a series of cognitive/social tasks (an intelligence test, listening to a marital argument, and performing a star-tracing task), which were later assayed for IL-6. Children with higher salivary IL-6 levels reported increased Eveningness predispositions and their parents reported higher levels of Sleep Disordered Breathing. Furthermore, lower levels of sleepiness, longer sleep amount, and better quality sleep in children were each predictive of increased IL-6 reactivity from pre- to post-task conditions. The findings illustrate (for the first time to our knowledge) that sleep disruptions in otherwise healthy and normally developing children may be associated with individual differences in levels of IL-6 in saliva.     

A Degradable and Antimicrobial Surface‐Attached Polymer Hydrogel

Surface‐attached, degradable polymer hydrogels with potential antimicrobial activity are reported. They are obtained by ring‐opening metathesis copolymerization (ROMP) of a monomer with potential bioactivity and a monomer that carries a benzophenone cross‐linker and a hydrolyzable group. The hydrolyzable group is either an ester or an anhydride group. The copolymers thus obtained are spin‐coated onto silicon wafers and UV‐irradiated to induce C,H cross‐linking of the benzophenone groups and obtain the target polymer networks. Immersion of these networks into aqueous media triggers network degradation. The degradation speed depends on the nature of the intended break points (ester or anhydride groups), the number of cross‐links per polymer chain, and the surrounding medium. By releasing bioactive polymer fragments to the medium (“leaching”) and by regenerating the hydrogel surface during the degradation process, the hydrogels potentially have two ways to prevent biofilm formation on their surface.     

Meta-analysis of the efficacy of nicotine replacement therapy for smoking cessation: differences between men and women

Gender differences in the efficacy of nicotine replacement therapies (NRTs) were examined in a meta-analytical review of 90 effect sizes obtained from a sample of 21 double-blind, placebo-controlled randomized studies. Although NRT was more effective for men than placebo at 3-month, 6-month, and 12-month follow-ups, the benefits of NRT for women were clearly evident only at the 3- and 6-month follow-ups. Giving NRT in conjunction with high-intensity nonpharmacological support was more important for women than men. That is, NRT and low support were efficacious for women at only short-term follow-up, and men benefited from NRT at all the follow-ups regardless of the intensity of the adjunct support. The results suggest that long-term maintenance of NRT treatment gains decrease more rapidly for women than men.