QuickVue Influenza Test for Rapid Detection of Influenza A and B Viruses in a Pediatric Population

The performance of a lateral-flow immunoassay, the QuickVue Influenza Test, for detection of influenza A and B viruses in comparison with that of cell culture was evaluated by using nasopharyngeal aspirates, in viral transport medium, from children with respiratory tract infections. The sensitivity and specificity were 79.2 and 82.6%, respectively.     

Stable micro-dystrophin gene transfer using an integrating adeno-retroviral hybrid vector ameliorates the dystrophic pathology in mdx mouse muscle

The ability to transfer the dystrophin gene stably to the skeletal muscle of DMD patients is a major confounding issue in establishing an effective gene therapy for this disease. To overcome this problem, we have examined the ability of muscle fibres from mdx mice to act as in situ factories of retroviral vector production. Tibialis anterior (TA) muscles from 4-week-old mdx mice were injected with an adenoviral vector expressing LacZ within a retroviral expression cassette (AdLZIN). Retroviral vector production was induced by the inclusion of two additional adenoviral vectors expressing retroviral gag-pol (AdGagPol) and 10A1 env genes (Ad10A1). Upon introduction of infected muscles into cell culture, colonies of beta-galactosidase-expressing myotubes formed only in cultures where the muscle was injected with AdLZIN, AdGagPol and Ad10A1, but not from muscle injected with AdLZIN only. Muscles from mdx/nude mice producing retroviral vector displayed a 4.6-fold increase in beta-galactosidase-positive myofibres after 1 month, compared with contralateral muscle in the same animal injected with AdLZIN and AdGagPol only. By constructing a hybrid adeno-retroviral vector expressing a truncated micro-dystrophin construct (AdmicroDyIN), we were able to partially correct the mdx dystrophic phenotype. AdmicroDyIN-mediated expression of micro-dystrophin in mdx TA muscle restored the formation of the dystrophin-associated glycoprotein complex and significantly reduced the level of muscle degeneration over uninjected controls. By stimulating in situ production of retroviral vector expressing micro-dystrophin, we achieved 92%+/-6% transduction of myofibres in the TA muscle by 4 weeks. Strikingly, by 3 months post injection, micro-dystrophin was still expressed to high levels in nearly all the myofibres of the TA muscle. By comparison, there was a pronounced drop in the levels of micro-dystrophin expressed by muscles injected with AdmicroDyIN only. Finally, using a novel PCR approach, we detected reverse-transcribed, integrated proviral sequences in TA muscle genomic DNA by 4 weeks post injection, the levels of which were found to increase after 3 months.     

The calcium ion dependence of scallop myosin ATPase activity

Summary The ATPase activity of scallop (Pecten maximus) striated adductor myosin and heavy meromyosin (HMM) have been investigated as a function of [Ca²⁺] using formycin triphosphate (FTP) as a fluorescent ATP analogue. The FTPase activity of the regulated fraction of these preparations was activated steeply over the range of 0.1 to 1M [Ca²⁺ ], implying the existence of a form of cooperativity that is intrinsic to the myosin heads. In addition to the previously characterised heterogeneity with respect to an unregulated fraction, the regulated fraction of HMM was resolved into two populations whose activities showed a slightly different dependency on [Ca²⁺ ]. This was revealed unambiguously at intermediate levels of activation where, in some experiments, the product release rate constants differed for the two populations by more than fivefold. At maximum relaxation or maximum activation, these rate constants differed by two-to three-fold and were not clearly resolved by the multiexponential fitting procedure. The populations might arise as a consequence of isoenzymes, modification during preparation or slowly interconverting conformers; Ca²⁺ binding itself being a rapid equilibrium process in both populations. FTP turnover by myosin could not be analysed in such detail because of the technical problems of measuring the fluorescence of a suspension of filaments, but the rates of the elementary steps appeared similar to those of HMM. The fraction of unregulated molecules in myosin preparations was comparable to that of HMM indicating that if it is a consequence of preparative damage, the modification must occur prior to tryptic digestion.     

Th1 cell development induced by cysteine proteinases A and B in localized cutaneous leishmaniasis due to Leishmania guyanensis

The cysteine proteinases CPA and CPB from Leishmania major induced Th1 responses in patients with leishmaniasis due to Leishmania guyanensis. Furthermore, cysteine proteinases induced neither interleukin 4 (IL-4) nor IL-13 and low levels of IL-10 in controls and patients. The results suggest that CPs would be quite good candidates for a vaccine against different Leishmania species.     

Loss of RhoB expression in human lung cancer progression.

PURPOSE: RhoB is a low molecular weight GTPase belonging to the Ras protein superfamily. Whereas most Rho proteins have been shown to have a positive role in proliferation and malignant transformation, the specific role of RhoB appears more divergent. We reported previously that RhoB inhibits cell proliferation in various human cancer cells. Here, we studied the specific role played by RhoB in human lung cancer. EXPERIMENTAL DESIGN: We analyzed the expression of RhoB protein by immunostaining in human lung tissues ranging from normal to invasive carcinoma from different histological types in two large independent studies of, respectively, 94 and 45 samples. We then studied the cellular effect of RhoB overexpression in a model of lung cancer (A549, adenocarcinoma) and tumorigenicity in nude mice. RESULTS: We showed in both studies that RhoB protein was expressed in normal lung and decreased dramatically through lung cancer progression (P < 0.01). Interestingly, RhoB expression was lost in 96% of invasive tumors and reduced by 86% in poorly differentiated tumors compared with the nonneoplastic epithelium. Moreover, the loss of expression of RhoB correlated significantly with tumor stage and proliferative index, whereas no correlation was found between RhoB and p53 or Bcl-2 expression. We then showed that ectopic expression of RhoB in lung cancer cell line A549 suppressed cell proliferation, anchorage-independent growth, and xenograft tumor growth in nude mice. CONCLUSIONS: RhoB loss of expression occurs very frequently in lung carcinogenesis, reinforcing its putative tumor suppressive activity, and raising the value of its potential use in cancer therapy.     

Nicotine-associated cues maintain nicotine-seeking behavior in rats several weeks after nicotine withdrawal: reversal by the cannabinoid (CB1) receptor antagonist, rimonabant (SR141716).

Conditioned stimuli are important for nicotine dependence and may trigger craving and relapse after prolonged nicotine abstinence. However, little is known about the pharmacology of this process. Among the systems that have been shown to play a role in drug-seeking behavior is the endocannabinoid transmission. Therefore, the present study examined the resistance to extinction of drug-seeking behavior elicited by nicotine-associated environmental stimuli and the effects of the selective CB1 cannabinoid antagonist rimonabant (SR141716) on the reinforcing effects of nicotine-related stimuli. Rats were trained to self-administer nicotine (0.03 mg/kg/injection, i.v.) under conditions in which responding was reinforced jointly by response-contingent nicotine injections and stimuli (light and tone). After self-administration acquisition, nicotine was withdrawn and lever pressing was only reinforced by contingent presentation of the audiovisual stimuli. Under such a condition, responding persisted for 3 months, following which nonpresentation of the cues produced a progressive extinction of responding. As expected, rats trained to lever-press for saline injections paired with the audiovisual stimuli did not acquire the self-administration. These findings indicate that the cues required learned association with nicotine to acquire reinforcing properties and to function as conditioned reinforcers. When administered 1 month following nicotine withdrawal, rimonabant (1 mg/kg, i.p.) decreased conditioned behavior. These results showing the persistence of a nicotine-conditioned behavior are congruent with the role of nicotine-related environmental stimuli in nicotine craving in abstinent smokers. Rimonabant, which has been shown previously to reduce nicotine self-administration, may be effective not only as an aid for smoking cessation but also in the maintenance of abstinence.     

An integrative view of Luria’s perspective on arithmetic problem solving: The two sides of environmental dependency

Introduction: A. R. Luria was the first author to hypothesize that executive dysfunction can lead to specific deficits in arithmetic problem solving, showing that patients’ performance depends on the structure of the tasks. Cummings (1995. Anatomic and behavioral aspects of frontal-subcortical circuits. Annals of the New York Academy of Sciences, 15, 1–13) proposed the term “environmental dependency” to define such behavioral disorders triggered by the characteristics of the test and pointed out also the role of executive impairments. Few studies compare executive functioning and problem solving in brain-damaged patients, and none have examined the question from this point of view. Thus, the main aim of the present paper was to study the relationship between environmental dependency and executive functions. Method: Fifty neurological patients with frontal, subcortical, and posterior brain lesions were compared to 45 matched healthy controls and were divided into two groups (dysexecutive/nondysexecutive) according to their performances on executive tasks. Then, we confronted the results of the two groups on an experimental protocol designed in accordance with Luria’s proposals. We made also comparisons between groups on the basis of lesion location. Results: Our findings indicate a high association between executive functions and environmental dependency, showing that dysexecutive patients’ performances were dependent on task demands. In addition, a specific frontal behavior not associated with executive functions and characterized by the solving of insoluble problems was highlighted. Conclusion: The discussion focused on the interest to take into account the methodological and clinical contributions of environmental dependency. Based on our findings and theoretical arguments, we highlight the need to fractionate this concept.     

Myocardial asynchronism is a determinant of changes in functional mitral regurgitation severity during dynamic exercise in patients with chronic heart failure due to severe left ventricular systolic dysfunction.

AIMS: Functional mitral regurgitation (MR) and myocardial asynchronism occur commonly in patients with dilated cardiomyopathy and affect adversely their prognosis and symptoms. The aim of this study was to evaluate the mechanisms of changes in MR severity during dynamic exercise in patients with chronic heart failure (CHF). METHODS AND RESULTS: Seventy patients with CHF due to left ventricular (LV) systolic dysfunction [LV ejection fraction (EF) <40%] and functional MR were studied. All were in sinus rhythm. Medications were left unchanged for the study. Each patient performed a maximal symptom-limited exercise test with continuous 2D-Doppler echocardiography. Mitral regurgitant volume (RV) and effective regurgitant orifice (ERO) were determined at rest and during exercise. LV asynchrony using Doppler tissue imaging and interventricular asynchrony using conventional pulsed-Doppler were evaluated at rest. Resting LV EF averaged 25+/-8%. Mean resting LV and interventricular mechanical delays were 56+/-50 and 43+/-37 ms, respectively. The overall median values for mitral ERO and RV did not significantly change during dynamic exercise (11 [7-16] vs. 11 [6-21] mm2 and 14 [10-22] vs. 12 [9-23] mL, respectively). However, changes in mitral ERO and RV were individually variable and significantly correlated with the degree of LV asynchronism (r=0.66, P<0.0001 and r=0.66, P<0.0001, respectively). CONCLUSION: Changes in MR are variable during dynamic exercise. LV asynchronism at rest substantially contributes to worsening of functional MR during dynamic exercise in patients with CHF due to LV systolic dysfunction.