Biomedical subjects

David Wolf

Publications and source records attributed to David Wolf.

9 recordsLinked to original sources

PubMed2006

An ongoing study of group treatment for men involved in problematic Internet-enabled sexual behavior.

Exponential advances have been made regarding computer/Internet technology in the past decade. This growth, in large part, can be attributed to greater access to, affordability of, and anonymity while on the computer. However, this progress has also produced negative psychological issues. Problematic Internet-enabled sexual behavior (IESB) has increasingly affected individuals' family relationships, work productivity, and academic success. This article is the first-known, empirically based outcome study regarding the effectiveness of group therapy treatment for men with problematic IESB. These closed-groups, which ran for 16 weeks, used a combination of Readiness to Change (RtC), Cognitive Behavioral Therapy (CBT), and Motivational Interviewing (MI) interventions. Five groups were analyzed for this paper (yielding a total N of 35), with the average member's age being 44.5 years old. Three different scales (the Orzack Time Intensity Survey, the BASIS-32, and the BDI) were used to track participants' progress across time. The results demonstrated that this group treatment intervention significantly increased members' quality of life and decreased the severity of their depressive symptoms. However, the protocol failed to reduce participants' inappropriate computer use. Regarding comorbidity, the results showed the following: members in the "anxiety" category responded best to the current treatment, those in the "mood" cluster responded relatively positively, and those in the "A-D/HD" category failed to respond significantly. It is clear from this report that more attention must be focused on the treatment of problematic IESB, as opposed to exploratory studies.

Cognitive Behavioral Therapy↗

PubMed2005

Cardioprotective effects of the novel selective endothelin-A receptor antagonist BSF 461314 in ischemia-reperfusion injury.

OBJECTIVE: The aims of the study were to visualize the dynamics of ischemia-reperfusion injury by real-time myocardial contrast echocardiography and to investigate the cardioprotective effects of the novel endothelin-A receptor antagonist BSF 461314. BSF 461314 reduced infarct size by 47% and preserved microvascular integrity. Real-time myocardial contrast echocardiography allowed visualization of postischemic microvascular dysfunction and quantification of cardioprotective effects of selective endothelin antagonism. Blood flow index A x beta was reduced in anterior segments during ischemia compared with baseline (0.06 +/- 0.01 vs 0.98 +/- 0.2 dB/s) but was higher in the BSF 461314 group after 120 minutes of reperfusion (0.7 +/- 0.08 vs 0.3 +/- 0.05 dB/s, P = .015). Therefore, selective endothelin-A receptor antagonism improved microvascular integrity during postischemic reperfusion. Real-time myocardial contrast echocardiography accurately detected changes in microvascular reflow. BACKGROUND: Endothelin-1 is a potent vasoconstrictor and elevated in myocardial ischemia. The aims of the study were to examine cardioprotective effects of the novel selective endothelin-A receptor antagonist BSF 461314 and to visualize changes in the microvasculature by real-time myocardial contrast echocardiography (MCE). METHODS: A total of 16 open-chest pigs underwent 45 minutes of left anterior descending coronary artery occlusion followed by 120 minutes of reperfusion. A total of 1 mg/kg BSF 461314 or vehicle was given intravenously before reperfusion. Serial MCE was performed to assess changes in myocardial blood flow A x beta and perfusion defect size. Myocardial blood flow was measured by fluorescent microspheres and infarct size was measured by triphenyltetrazolium chloride tissue staining. RESULTS: Dynamics of infarct size expansion and tissue perfusion were correctly assessed by MCE. A x beta Was reduced in anterior segments during left anterior descending coronary artery occlusion (0.06 +/- 0.01 dB/s) compared with baseline (0.98 +/- 0.2 dB/s), approached higher levels postrecanalization (1.2 +/- 0.1 dB/s), but gradually decreased during reperfusion (0.3 +/- 0.05 dB/s, P < .01). After 120 minutes of reperfusion A (2.1 +/- 0.5 vs 1.0 +/- 0.6 dB, P < .03), beta (0.36 +/- 0.09/s vs 0.21 +/- 0.09/s, P = .01), and A x beta (0.7 +/- 0.08 vs 0.3 +/- 0.05 dB/s, P = .015) in the risk area were higher in the BSF 461314-treated group compared with vehicle indicating preserved myocardial perfusion. Triphenyltetrazolium chloride staining confirmed a 47% reduction in infarct size by BSF 461314. CONCLUSIONS: Selective endothelin-A receptor antagonism improved microvascular integrity during postischemic reperfusion. Real-time MCE allows visual and quantitative evaluation of dynamics of myocardial ischemia-reperfusion injury and monitoring of cardioprotective effects during pharmacologic interventions.

Animals↗

PubMed2004

Comparison of real-time myocardial contrast echocardiography for the assessment of myocardial viability with fluorodeoxyglucose-18 positron emission tomography and dobutamine stress echocardiography.

Little is known about the diagnostic value of real-time myocardial contrast echocardiography (MCE) for the assessment of myocardial viability. We compared the diagnostic accuracy of MCE with that of low-dose dobutamine stress echocardiography (DSE) and of combined technetium-99 sestamibi single-photon emission computed tomography and fluorodeoxyglucose-18 positron emission tomography and investigated whether quantitative assessment of myocardial blood flow could increase its diagnostic value. Cardiac imaging was performed with these 3 methods in 41 patients who had ischemic heart disease (ejection fraction < 40%) and were being considered for revascularization. Follow-up echocardiograms were obtained after 3 to 6 months in revascularized patients, and increased regional function served as a standard reference for assessment of myocardial viability. A control group of 25 patients who had no coronary artery disease underwent MCE to assess normal values of myocardial perfusion parameters. Recovery of myocardial function was predicted by MCE with a sensitivity of 86% and a specificity of 43%. Nuclear imaging was comparably sensitive (90%) and specific (44%), whereas low-dose DSE was similarly sensitive (83%) but more specific (76%). Normalization of myocardial signal intensity to that of the control group significantly increased the specificity of MCE from 43% to 64% and the accuracy from 73% to 81%. A combination of quantitative MCE and DSE provided the best diagnostic characteristics, with a sensitivity of 96%, a specificity of 63%, and an accuracy of 83%. Thus, MCE is useful for assessing myocardial viability. Normalization of contrast intensity to that of a reference control group is a valid approach for detection of myocardial viability and expands on information obtained from visual MCE and DSE.

Adult↗

PubMed2004

Evaluation of cardioprotective effects of recombinant soluble P-selectin glycoprotein ligand-immunoglobulin in myocardial ischemia-reperfusion injury by real-time myocardial contrast echocardiography.

OBJECTIVES: The purpose was to examine the cardioprotective effects of recombinant P-selectin glycoprotein ligand-immunoglobulin (rPSGL-Ig) in ischemia-reperfusion injury by real-time myocardial contrast echocardiography (MCE). BACKGROUND: P-selectin mediates leukocyte recruitment into areas of inflammation. METHODS: Sixteen pigs underwent 45 min of left anterior descending coronary artery occlusion followed by reperfusion and received rPSGL-Ig or vehicle. To assess changes in myocardial perfusion (A x beta), MCE was performed. RESULTS: After 120 min of reperfusion, A x beta in the risk area was higher (0.84 +/- 0.15 dB/s vs. 0.28 +/- 0.1 dB/s, p < 0.0001), and the infarct size was lower (30.3 +/- 12% vs. 57 +/- 14%, p = 0.002) in the rPSGL-Ig group compared with the vehicle group. CONCLUSIONS: Recombinant PSGL-Ig improved postischemic reflow accurately detected by real-time MCE.

Animals↗

PubMed2004

Fourier phase analysis can be used to objectively analyze real-time myocardial contrast echocardiograms.

BACKGROUND: Real-time myocardial contrast echocardiography (MCE) is increasingly used to assess myocardial perfusion. However, objective methods for evaluating MCE are not yet widely available. We sought to validate the ability of Fourier analysis applied to MCE to assess serial changes in microvascular perfusion during coronary occlusion and reperfusion. METHODS: Six pigs underwent 45 min of left anterior descending coronary artery (LAD) occlusion followed by 120 min of reperfusion. Real time MCE was performed at baseline, during coronary occlusion, and at 5, 30, 60 and 120 min of reperfusion. Signal intensities from replenishment curves were fitted to an exponential function to obtain plateau SI (A) and the rate of SI rise (b). MCE images were mathematically transformed using a first-harmonic Fourier algorithm displaying the sequence of myocardial intensity changes as phase angles in parametric images. The phase angle difference (PD) of posterior vs. anterior region was calculated as an index of myocardial opacification heterogeneity and compared to MCE index of myocardial blood flow A x b. RESULTS: After initial hyperemia, a progressive reduction in flow was observed during reperfusion. During LAD occlusion signal intensities were significantly reduced in anterior regions (A x b = 0.02+/-0.01) compared to baseline (1.2+/-0.34, p < 0.01) defining risk areas and approached higher levels postrecanalization (A x b = 1.48+/-0.6) but gradually decreased during 120 min of reperfusion (A = 0.51+/-0.3, p < 0.01). Similarly, profiles of phase angles in LAD perfusion territorities were consistently modified during reperfusion. The mean PD at baseline was 18 degrees+/-15 degrees. PD decreased during coronary occlusion to -108 degrees+/-38 degrees, increased to 29 degrees+/-19 degrees postrecanalization but decreased to -61 degrees+/-35 degrees after 120 min of reperfusion. PD significantly correlated with A (r = 0.8, p < 0.0001) and b (r = 0.73, p < 0.0001). CONCLUSIONS: The progressive reduction in post-ischemic microvascular perfusion was accurately detected by real-time MCE. Fourier phase imaging is feasible to quantify dynamics of myocardial opacification in a simple and objective format and is a promising approach for the interpretation of contrast echocardiograms.

Animals↗

PubMed2003

Controlled-release systems for the delivery of cyromazine into water surface.

Controlled-release systems (CRSs) for the insect growth regulator cyromazine (Neporex), as a larvicide against Culex pipiens (Culicidae) mosquitoes, are under development. Despite promising results obtained previously for both in vitro (dissolution tests) and in vivo systems (mosquito larvae floating on water surfaces), it was evident that the CRSs did not remain afloat for sufficiently long times. The present study was thus conducted to determine the relationship between the process parameters and the potential contact time of the active ingredient with the mosquito larvae. A series of CRSs were prepared by an extrusion process, alone or in combination with a supplementary coating. The active ingredient was incorporated into the matrix or the coating. The matrix comprised low-density polyethylene 600 and perlite, and the coating, a polyurea with or without the addition of paraffin wax. The study showed that the cumulative release of the active ingredient into water could be controlled by manipulating the preparation techniques, the types and concentrations of inert materials, and the concentration of the active ingredient.

Animals↗

PubMed2003

Controlled-release systems for the insect growth regulator pyriproxyfen.

A simple technique was developed for the production of controlled-release systems (CRSs) for pyriproxyfen, an insect growth regulator active against the larvae of Culex pipiens, the most common species of mosquito found in developed countries. The CRSs consisted of a spongy core material encapsulated in a coating of a polyurethane or polyurea hydrogel, into which the active ingredient had been incorporated. The coating also included a surfactant to improve the low solubility in water of pyriproxyfen. The light core material enabled the CRS to float on the water surface, where the mosquitoe larvae are found. The type and amount of the polymeric coating and the amount of surfactant influenced the release profiles into water of the active ingredient. The release profiles of the CRSs were adjusted to the life cycle of the C. pipiens mosquito in order to obtain their optimal activity on the eighth day, which corresponds to the time of larval maturity.

Animals↗

PubMed2002

Release characteristics of encapsulated formulations incorporating plant growth factors.

The release characteristics of encapsulated formulations containing a combination of plant growth factors (PGF)--plant hormones (IBA, paclobutrazol), nutrients (fertilizers, microelements), and fungicide (prochloraz)--were studied. The formulations were prepared by encapsulating the active ingredients in a polyethylene matrix and, in some cases, subsequently coating the product with polyurethane. Dissolution experiments were carried out with both coated and non-coated formulations to determine the sustained release patterns of the active ingredients. The PGF controlled-release systems obtained have been shown to promote development of root systems, vegetative growth, and reproductive development in cuttings, potted plants, or garden plants of various plant species. These beneficial effects are attributable to the lasting and balanced PGF availability provided by these systems.

Capsules↗

PubMedDate not supplied

Interaction of mucin with cholesterol enriched vesicles: role of mucin structural domains.

We utilized fluorescence recovery after photobleaching (FRAP) and fluorescence correlation spectroscopy (FCS) to examine the role of gallbladder mucin (GBM) in promoting the aggregation and/or fusion of cholesterol enriched vesicles. By fluorescent labeling either the vesicle or the mucin, we could examine the change in vesicle size as well as changes in mucin's diffusion constant. Both FRAP and FCS show that GBM has a profound effect in inducing vesicles to aggregate/fuse, particularly after overnight incubation. GBM mucin domains (either protease digested or reduced GBM) are not as effective as native GBM. Intact GBM alone was able to shorten crystal appearance time and increase the number of crystals nucleated by polarized optical microscopy. In summary, our findings would suggest that both glycosylated and nonglycosylated domains of GBM are involved in early aggregation of cholesterol enriched vesicles but that this effect is reversible in the absence of nonglycosylated domains.

Animals↗