Effects of negative pressure wound therapy on fibroblast viability, chemotactic signaling, and proliferation in a provisional wound (fibrin) matrix

Vacuum Assisted Closure brand Negative Pressure Wound Therapy (V.A.C. NPWT) has been shown to be an effective therapeutic option for the treatment of recalcitrant wounds; however, the mechanism of action at the cellular level remains to be elucidated. Here, we examined the effects of negative pressure wound therapy, manifolded with two different dressings, on fibroblast viability, chemotactic signaling, and proliferation in a fibrin clot matrix. Fibroblasts were grown in a three-dimensional fibrin matrix and were treated for 48 hours with either V.A.C. NPWT and GranuFoam Dressing, or with gauze under suction, or as static controls without negative pressure or dressings. Cells treated by gauze under suction showed significantly greater cell death and stimulated less migration and proliferation than static and V.A.C. NPWT-treated cells (p<0.05). Apoptosis was also significantly higher in gauze under suction than in static treatments. These results indicate that the dressing material has a significant effect on cell response following negative pressure wound therapy. The ability to support cell growth, stimulate chemotaxis, and proliferation without increasing apoptosis may provide an insight into the mechanisms of action of V.A.C. NPWT.     

Plasma pharmacokinetics of high-dose oral busulfan in children and adults undergoing bone marrow transplantation

Abstract: We have analyzed the plasma pharmacokinetics of busulfan in 272 patients receiving high-dose oral busulfan and intravenous cyclophosphamide in conjunction with allogeneic or autologous bone marrow transplantation. The patients ranged in age from 2 months to 59 yr (mean 10, median 12 yr) and had the following diagnoses: thalassemia or sickle cell anemia (n = 74); leukemia or myelodysplasia (n = 112); inborn errors of metabolism (n = 41) or immunodeficiency (n = 45). Plasma specimens were collected following the first dose for each patient which ranged from 1 to 4 mg/kg (mean ± SD, 1.21 ± 0.41, median 1.15). Busulfan was quantitated using ultraviolet absorbance detection after derivatization and HPLC separation. Pharmacokinetic parameters were derived by modeling the raw data to fit first-order single compartment kinetics. The kinetic parameters showed wide interpatient variability independent of age and diagnosis. There was a statistically significant correlation of age with the following parameters: area under the curve (AUC); maximal concentration; minimum concentration; clearance; volume of distribution and absorption half-time. The coefficients of determination (i.e. correlation coefficient squared) were low ranging from 0.04 to 0.12 implying only a small part (i.e. 4–12%) of the variance was explained by age. Although busulfan pharmacokinetics are age-related most of the variability is not explained by age or diagnosis.     

Angiotensin converting enzyme insertion/deletion polymorphism does not influence postcardiac transplantation hypertension onset or progression.

BACKGROUND: The angiotensin converting enzyme insertion deletion polymorphism (ACE I/D) has been associated with much cardiovascular pathology, including posttransplantation hypertension. Hypertension is a significant cause of morbidity and mortality after cardiac transplantation. We investigated the influence of the ACE I/D polymorphism on posttransplantation hypertension. METHODS: A total of 211 heart transplant recipients and 154 corresponding donors were genotyped for the ACE I/D polymorphism by polymerase chain reaction. ACE enzymatic activity was measured by spectrophotometric kinetic analysis. Sitting systolic and diastolic blood pressures were recorded at 3 consecutive visits, and the mean was calculated. Clinical data, including demographics and medication, were collected for all recipients. Results were analyzed by the chi-square test and analysis of variance, taking a p value of <0.05 to be significant. RESULTS: A total of 41.7% of the subjects were hypertensive (diastolic blood pressure >90 mm Hg) at the time of the study, with 79.6% taking at least one antihypertensive agent. We found no difference between the number of antihypertensive agents, cyclosporin dose and level, renal function, or systolic blood pressure for the different recipient or donor genotypes. We also found no significant correlation between ACE enzymatic activity and systolic or diastolic blood pressure. CONCLUSIONS: Our study of 211 recipients and 154 corresponding donors is the largest investigation of this polymorphism in a cardiac transplantation population. We found no apparent relationship between the ACE genotype (of either donor or recipient) and systemic hypertension (absolute measurements and the number or dose of antihypertensive agents used).     

Multipass Vector (Mpave) Technique with Nonablative Radiofrequency to Treat Facial and Neck Laxity

Background. Redundant facial and neck skin is a major feature of aging and historically has been corrected surgically. Recently, monopolar radiofrequency application has been introduced for nonablative tissue tightening of skin by volumetric heating of the deep dermis. It has been able to improve neck and cheek laxity and periorbital rhytides and to elevate eyebrows. However, questions remain as to the ideal parameters needed to optimize the use of radiofrequency.
Objective. To determine the safety and report on the efficacy of a radiofrequency application that involves a multipass vector (mpave) technique to target facial and neck skin laxity.
Methods. Twenty-five patients (skin types I to V) with mild to severe facial and neck laxity received one treatment session with monopolar radiofrequency. Treatment parameters, adverse events, and digital photographs were recorded. All patients were treated with a multipass vector technique consisting of four to five passes targeted over areas of skin that would most improve facial laxity. The multipass vector (mpave) treatment approach is described. Energy levels ranged from 62 to 91 J/cm2 per pulse.
Results. All patients experienced some immediate erythema and edema, which had completely resolved in most patients within 48 hours. No scarring or dyspigmentation was noted on follow-up at 6 and 12 weeks. Photographic analysis of pre- and post-treatment digital images revealed cosmetic improvement in facial and neck laxity in 96% of patients. The majority of patients demonstrated a moderate or better improvement. Stacked pulses in the submental region were shown to reduce fat.
Conclusions. The direct application of monopolar radiofrequency to facial and neck skin using a multipass vector (mpave) treatment approach was safely tolerated in patients of all skin types. Patient satisfaction correlated well with photographic analysis, and the technique was shown to be efficacious for most patients.     

Mapping the rat somatosensory pathway from the anterior cruciate ligament nerve endings to the cerebrum

The anterior cruciate ligament (ACL) serves as the primary restraint to anterior tibial translation. In addition to this biomechanical function, the ACL appears to have a function in neuromuscular control. This hypothesis was formulated after the discovery of mechanoreceptors within the ACL. The full somatosensory pathway from the ACL to the cerebrum has yet to be elucidated. In order to map this sensory pathway, we conducted a viral trans-synaptic tracing experiment using the neurotropic pseudorabies virus (PRV). The pseudorabies virus was injected into the ACL of rats and allowed to replicate and spread trans-synaptically for 6-7 days. The brain and spinal cord of each sacrificed rat was then removed and processed immunohistochemically to detect the presence of PRV. PRV-immunoreactive neurons were found to be localized in several different regions from the spinal cord to the cerebrum. Four nuclei in the reticular formation of the brain stem demonstrated strong positive labeling: the mesencephalic reticular nucleus, magnocellular reticular nucleus, paragigantocellular reticular nucleus, and gigantocellular reticular nucleus. This finding suggests that the nerve endings of the rat ACL project into the cerebrum and that the reticular formation may play an important role in the afferent pathway of those nerve endings.     

A Process and Outcomes Evaluation of the International AIDS Conference: Who Attends? Who Benefits Most?

The objective of the study was to conduct a process and outcomes evaluation of the International AIDS Conference (IAC). Reaction evaluation data are presented from a delegate survey distributed at the 2004 IAC held in Thailand. Input and output data from the Thailand IAC are compared to data from previous IACs to ascertain attendance and reaction trends, which delegates benefit most, and host country effects. Outcomes effectiveness data were collected via a survey and intercept interviews. Data suggest that the host country may significantly affect the number and quality of basic science IAC presentations, who attends, and who benefits most. Intended and executed HIV work‐related behavior change was assessed under 9 classifications. Delegates who attended 1 previous IAC were more likely to report behavior changes than attendees who attended more than 1 previous IAC. The conference needs to be continually evaluated to elicit the required data to plan effective future IACs.     

The overlap between personality disorders and major depressive disorder (MDD).

BACKGROUND: Research studies have focused attention on the importance of the comorbidity of personality disorders and depression. METHODS: The present review examines seven potential explanations for the overlap to clarify the nature of the relationship, if any, between depression and personality disorder diagnoses. RESULTS: There may be many explanations for the potential overlap of personality disorders (PD) and major depressive disorder (MDD). For example, the distinction between states and traits may not be as clear and definitive as suggested in the DSM-IV. In some cases, depression may influence personality pathology, and may even lead to personality disorders. In other cases, personality disorders may lead to MDD. CONCLUSION: Further research may clarify the nature of the relationship, if any, between depression and personality disorder diagnoses, as well as the relationship between comorbidity and treatment response.     

The detection of intracytoplasmic interleukin-1 alpha, interleukin-1 beta and tumour necrosis factor alpha expression in human monocytes using two colour immunofluorescence flow cytometry.

Two colour flow cytometry was used to analyse in situ cytokine expression by human monocytes. Whole blood was cultured in siliconised glass bottles, with or without E. coli lipopolysaccharide (LPS), for various times, and the mononuclear cells (MNCs) then exposed to a variety of permeabilisation procedures prior to flow cytometric analysis. Paraformaldehyde (PF)/saponin fixation preserved cellular morphology, and caused a reproducible degree of permeabilisation (estimated by propidium iodide inclusion: mean 94%, range 86-99% (n = 33)). After fixation with 4% PF and permeabilisation with 1% saponin at 0 degrees C in PBS containing 20% human serum, MNCs were incubated with phycoerythrin(PE)-conjugated mouse anti-CD14 (monocyte phenotype) and polyclonal rabbit anti-human interleukin-1 alpha (IL-1 alpha), IL-1 beta, tumour necrosis factor alpha (TNF-alpha), or control rabbit IgG. Binding of rabbit antibodies was detected using goat anti-rabbit IgG fluorescein isothiocyanate (FITC). FITC fluorescence was increased in CD14 PE positive cells with the three anti-cytokine antibodies following LPS stimulation, compared with controls. There was a reproducible dose related response in monocyte IL-1 beta and TNF-alpha expression following LPS stimulation, with early peaks in TNF-alpha (2 h), compared with IL-1 beta (4 h), and IL-1 alpha (12 h). Specificity of this cytokine detection system was confirmed by inhibition studies using the corresponding recombinant human cytokines, by an absence of staining in CD14 negative or unpermeabilised MNCs, and by the characteristic cytoplasmic localisation of the different cytokines visualised with UV immunochemistry. Hence, the methods described here provide a reproducible, semiquantitative and specific assay for the detection of cell associated monokines. The technique may be applicable to the analysis of a variety of different cytokines in other phenotypically defined cell populations.     

Decomposing Area of Residence Differences in Multiple Regression Studies: The Relative Contributions of Independent Variables and Model Coefficients

When rural/urban differences are found in health status or health care use, it is often desirable to identify those factors (such as age, social structure, income, etc.) that influence such differences. To this end, researchers often test rural/urban differences in age, social structure, income, etc., for statistical significance. Also, researchers commonly perform multivariate analyses (such as multiple regressions) to examine rural-urban differences in the influence of various independent variables on the dependent variable of interest. Frequently, researchers discover: (1) statistically significant rural/urban differences in the independent variables (such as age, social structure, income, etc.) and (2) statistically significant rural/urban differences in the effects of these independent variables (i.e., statistically significant rural/urban differences in regression coefficients). The analysis typically stops here, without addressing the relative contributions of (1) and (2) to the rural/urban differences in the dependent variable. This paper argues that the relative contributions of (1) and (2) have important implications for the way policy-makers address rural health problems. This paper presents a method for assessing the relative contributions of differences in the independent variables and differences in regression coefficients to observed differences in the dependent variable, and illustrates the application of the method by analyzing rural/urban differences in the risk of institutionalization.