Human submandibular saliva inhibits human immunodeficiency virus type 1 infection by displacing envelope glycoprotein gp120 from the virus

Actin is a highly conserved, ubiquitous cytoskeletal protein, which is essential for multiple cellular functions. Despite its small size (Mr = 42 000), unpolymerized forms of actin, as well as polymerized forms, exist primarily in the cytoplasm, excluded from the nucleus. Although spatial control of actin is crucially important, the molecular mechanisms ensuring the cytoplasmic localization of unpolymerized actin have not been revealed so far. In this paper we report that actin contains two leucine-rich type nuclear export signal (NES) sequences in the middle part of the molecule, which are both shown to be functional. Monomeric actin, when injected into the nucleus, was rapidly exported in a manner which was sensitive to leptomycin B (LMB), a specific inhibitor of NES-dependent nuclear export. LMB treatment of cells prevented nuclear exclusion of endogenous actin, inducing its nuclear accumulation. Furthermore, actin mutants with disrupted NESs accumulated in the nucleus. Expression of these NES-disrupted actin mutants, but not of wild-type actin, induced a decrease in the proliferative potential of the cell. These results reveal a novel molecular mechanism controlling the subcellular distribution of actin.     

The relationship between magnesium and calcium kinetics in 9- to 14-year-old children

A. J. Tomarken and R. J. Davidson (1994) reported that defensiveness is characterized by relative left frontal brain activation. Because they examined only women, gender differences in this relation are possible. In the present study, resting alpha asymmetries in right-handed men (n = 25) and women (n = 60) were related to defensiveness, measured by the Eysenck Personality Questionnaire L scale. These results were similar to those of Tomarken and Davidson in that defensiveness correlated positively with relative left frontal activation in women. An unexpected finding was that high-defensive men showed relative right frontal activation, a result virtually opposite that for women. These results imply that the nature of defensiveness as a coping strategy may vary as a function of gender.     

Why a superman cannot help a tsunami: Activation of grammatical class influences resolution of young and older adults' tip-of-the-tongue states.

Young (aged 18-23), young-old (aged 61-73), and old-old (aged 75-89) adults saw general knowledge questions whose answers were designated target words. Participants responded that they knew, did not know, or were having a tip-of-the-tongue (TOT) state for the answer. After TOT states, participants saw a 5-word list in which 1 was a "prime" containing the target's first syllable and that shared or differed in part of speech from the target. The question was then presented again, and target retrieval was attempted. Results revealed age differences in resolution of TOT states as a function of the prime's grammatical class. Following different part-of-speech primes, young and young-old adults showed increased resolution of TOT states relative to phonologically unrelated words, whereas old-old adults did not. In contrast, old-old adults demonstrated decreased resolution of TOT states following same part-of-speech primes, whereas young and young-old adults' TOT resolution was unaffected. These findings are consistent with interactive activation theories of speech production in which phonology can influence lexical selection and also suggest an increased susceptibility to phonological competitors in the later stages of the aging process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Optimality in human motor performance: Ideal control of rapid aimed movements.

A stochastic optimized-submovement model is proposed for Fitts' law, the classic logarithmic trade-off between the duration and spatial precision of rapid aimed movements. According to the model, an aimed movement toward a specified target region involves a primary submovement and an optional secondary corrective submovement. The submovements are assumed to be programmed such that they minimize average total movement time while maintaining a high frequency of target hits. The programming process achieves this minimization by optimally adjusting the average magnitudes and durations of noisy neuromotor force pulses used to generate the submovements. Two new experiments on rapid wrist rotations yield additional support for the stochastic optimized-submovement model. Experiment 1 revealed that the mean durations of primary submovements and of secondary submovements, not just average total movement times, conform to a square-root approximation of Fitts' law derived from the model. Also, the spatial endpoints of primary submovements have standard deviations that increase linearly with average primary-submovement velocity, and the average primary-submovement velocity influences the relative frequencies of secondary submovements, as predicted by the model. During Experiment 2, these results were replicated and extended under conditions in which subjects made movements without concurrent visual feedback. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Resonantly enhanced 26 GHz parametric upconversion of CO2laser in NH3

Resonantly enhanced three-wave mixing of the 10.784 μmR(18) line of the C¹³O2¹⁶laser and microwave radiation at 26.378 GHz in Stark tunable N¹⁴H3has resulted in upconverted parametric output at 10.774 μm. The energy levels of N¹⁴H3involved in the interaction and the apparatus used in the experiment are described. Experimental results showing saturation of the parametric signal with increasing N¹⁴H3pressure, input microwave power, and input laser power are described.     

A site of interaction between pleckstrin's PH domains and G beta gamma

Pleckstrin is a 40 kDa substrate for protein kinase C found in platelets and neutrophils. Based upon its sequence, pleckstrin contains two of the recently-described PH domains that are thought to be binding motifs for phosphatidyl 4,5-bisphosphate (PIP2) and/or G protein beta gamma heterodimers (G beta gamma). In the present studies we have examined the interaction between pleckstrin and G beta gamma by incubating pleckstrin fusion proteins with lysates from human platelets. In this analysis, both the N-terminal and C-terminal PH domains from pleckstrin bound G beta gamma in vitro, as did peptides containing as little as the first 30 residues of the C-terminal pleckstrin PH domain. Introduction of a point mutation into this region, analogous to the mutation in the Btk PH domain that causes X-linked immunodeficiency disease (XID) in mice, dramatically disrupted this interaction. We propose that pleckstrin may interact with G beta gamma, and that one potential site for this interaction involves the first 30 residues of pleckstrin's C-terminal PH domain.     

Sickle cell disease pain: II. Predicting health care use and activity level at 9-month follow-up.

Examined 9-mo follow-up data obtained from adults with sickle cell disease (SCD) participating in a longitudinal study of pain-coping strategies. Of 99 Ss completing the baseline assessment of pain-coping strategies, 89 (90%) completed a structured pain interview assessing health care use and activity reduction during painful episodes over the follow-up period. Regression analyses controlling for demographics and disease severity revealed that baseline Negative Thinking and Passive Adherence was associated with greater activity reduction and more frequent health care contacts during the subsequent 9 mo. Additional correlational analyses revealed that if levels of Negative Thinking and Passive Adherence increased from baseline to follow-up, this increase was associated with even further reductions in activity level during painful episodes. Changes in disease severity were not associated with any of the follow-up measures. Comparing pain-coping strategies assessed at baseline to pain-coping strategies measured at follow-up revealed that, without intervention, pain-coping strategies were relatively stable over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fixation point offsets facilitate endogenous saccades

The influence of light on the antipsoriatic drug dithranol was investigated. A Suntest CPS with xenon lamp and liquid cooling was used as light source for the test. Solutions of dithranol in different organic solvents and in therapeutical concentrations in excipients for the preparation of topical formulations were tested under defined conditions. The extent and rate of photodegradation was determined and compared with the degradation of light-protected solutions. The drug content in the solutions was measured by HPLC. Degradation products were characterised and identified by diode array technique and HPLC-mass spectrometry coupling. The results showed a strong dependency of the photodegradation on the excipient or solvent used.     

Smoking at home: The impact of smoking cessation on nonsmokers' exposure to environmental tobacco smoke.

Nonsmokers who live with smokers are at increased risk for chronic disease. This study evaluated the impact of eliminating smoking in the home on nonsmokers' environmental tobacco smoke (ETS) exposure. Nonsmokers participated in measurements of their ETS exposure before and after the smoker in their home quit smoking. A matched comparison group of nonsmokers from nonsmoking homes was also included. ETS exposure was assessed using passive nicotine monitors, an exposure diary, and a questionnaire. Nonsmokers from smoking homes had significantly higher exposure to ETS than those from nonsmoking homes. There was a 60% reduction in nicotine levels following smoking cessation by the household smoker. However, there were still detectable levels of nicotine measured at posttest. These results have important implications for individual risk reduction and public health policy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inability of methylprednisolone sodium succinate to decrease infarct size or preserve enzyme activity measured 24 hours after coronary occlusion in the dog

Methylprednisolone sodium succinate (50 mg/kg) was given 30 minutes before or after the start of a 90 minute occlusion of the left circumflex coronary artery (LCX) in one group of dogs. In a second group, methylprednisolone sodium succinate was given 15 minutes after permanent occlusion of the left anterior descending artery (LAD). Infarct size was determined by dehydrogenase staining after 24 or 96 hours. Heart slices were incubated with nitro-blue tetrazolium and nonstaining infarcted tissue was dissected and weighed. Myocardial depletion of creatine phosphokinase activity (CPK) and lactate dehydrogenase activity (LDH) were determined 24 hours after temporary LCX occlusion. When measured after 24 hours, methylprednisolone sodium succinate treatment did not reduce infarct size or decrease enzyme loss. After temporary LCX occlusion infarct size was 30.4 +/- 3.6% of left ventricular weight in control dogs and 30.0 +/- 2.3% in treated dogs. No significant difference in infarct size was observed in hearts examined 24 or 96 hours after myocardial infarction. After permanent LAD occlusion, infarct size in control dogs was 39.2 +/- 1.6% of left ventricular weight and 33.7 +/- 3.5% in treated dogs. CPK activity in the LCX area decreased by 26.5 +/- 7% in controls and by 28.1% +/- 7% in treated dogs. Treated dogs sustained a significantly greater fall in arterial blood pressure after LCX occlusion than did controls. During LCX occlusion and upon reperfusion, methylprednisolone sodium succinate treated dogs exhibited a significantly greater number of premature ventricular beats. Since infarct size and enzyme depletion were not reduced when measured after 24 hours, methylprednisolone sodium succinate treatment does not appear to have enhanced myocardial cell viability.