Comprehensive comparison of the VERSANT HIV-1 RNA 3.0 (bDNA) and COBAS AMPLICOR HIV-1 MONITOR 1.5 assays on 1,000 clinical specimens.

BACKGROUND: Plasma human immunodeficiency virus type 1 (HIV-1) RNA level is an important parameter for patient management, yet viral load assays from different manufacturers are not standardized. OBJECTIVES AND STUDY DESIGN: In this study, we evaluated the concordance between test results obtained for 1,000 plasma specimens collected from HIV-1-infected individuals measured with the VERSANT HIV-1 RNA 3.0 assay (bDNA) and the COBAS AMPLICOR HIV-1 MONITOR 1.5 test (PCR). We compared viral load values obtained by each of these assays throughout their dynamic ranges, with particular focus on samples with low viral load (i.e. 50-250 copies/mL), and calculated the estimated distribution of distinct plasma viral load levels for the entire study population modeled from the data observed in the study. RESULTS: We found that these two assays show excellent agreement, with a correlation (R(2)) of 0.957 and a slope of 1.004. The mean difference in viral load values between the two assays was less than 0.10-log(10) throughout the dynamic range and 98.2% of all samples had bDNA and PCR results within 0.5-log(10) of each other, a difference that is within the range considered to be a minimal change in plasma viremia. Moreover, the two assays show very similar results across all assay ranges tested. The estimated prevalence of samples with results <50 copies/mL, 50-250 copies/mL, and 250-500,000 copies/mL were 41.6%, 7.7%, and 49.7%, respectively, by the bDNA assay, and 42.4%, 6.9%, and 50.7%, respectively, by the PCR assay. CONCLUSION: Based on our findings from 1,000 clinical specimens, we do not see the need to re-establish a baseline value or apply a conversion factor when switching from one assay to the other. Since the majority of our patient population likely is infected with subtype B virus, it is unclear if our findings will apply to other patient populations with a greater incidence of infection with non-B subtypes.     

Antigen-induced, IgE-mediated degranulation of cloned immature mast cells derived from normal mice

Cloned, immature mast cells derived from normal mice were passively sensitized with mouse monoclonal IgE antibodies with specificity for DNP, and then stimulated to degranulate with DNP35-HSA. Cells were fixed for transmission electron microscopy or recovered for quantitation of histamine release at various intervals up to 30 minutes after antigen challenge. The cloned mast cells rapidly extruded the contents of their immature granules (dense progranular material and membrane-bound vesicles) to the exterior via multiple openings in the plasma membrane. Degranulation was associated with striking activation of the cell surface, characterized initially by elongation of surface processes, as well as by close approximation of strands of rough endoplasmic reticulum to the cell surface and by the development of coated pits. At later times after stimulation, degranulated mast cells had released nearly all of their granules and exhibited angular surfaces lacking elongated processes. These findings demonstrate for the first time that cloned, immature mast cells, like their mature counterparts, can undergo classic morphologic release reactions involving exocytosis of granules.     

Extracorporeal blood oxygenation and ozonation (EBOO): a controlled trial in patients with peripheral artery disease

BACKGROUND: Since 1990 our group has been using extracorporeal circulation to ozonate blood by an original method, known as extracorporeal blood oxygenation and ozonation (EBOO), with the aim of amplifying the results observed with ozone autohemotherapy. OBJECTIVE: To verify the hypothesis that EBOO improves the skin lesions typical of peripheral artery disease (PAD) patients. METHODS: Twenty-eight patients with PAD were randomized to receive EBOO or intravenous prostacyclin in a controlled clinical trial. The primary efficacy parameters were regression of skin lesions and pain,and improvement in quality of life and vascularisation. RESULTS: Patients treated with EBOO showed highly significant regression of skin lesions with respect to patients treated with prostacyclin. Other parameters that were significantly different in the two groups of patients were pain,pruritus, heavy legs and well-being. No significant differences in vascularisation of the lower limbs before and after treatment were found in either group.No side effects or complications were recorded during the 210 EBOO treatments. CONCLUSION: EBOO was much more effective than prostacyclin for treating skin lesions in PAD patients and also had a positive effect on patient general condition without any apparent change in arterial circulation. This suggests other mechanisms of action of EBOO.     

Functional role of low-voltage-activated dihydropyridine-sensitive Ca channels during the action potential in adult rat sensory neurones

Neuronal cell firing is crucial to nerve-nerve communication. The ability to produce consecutive action potentials is related to the activation of inward currents after each upstroke. If fast Na current is indeed responsible for the overshoot, it is still unclear which current drives membrane voltage to the Na threshold. In this study we present evidence that in adult rat sensory neurones a dihydropyridine-sensitive Ca channel exists in addition to the well characterized L-type, or high-threshold Ca channel. During stimulated action potential trains, L-type Ca channels open during the excitation wave, whereas activity of the other dihydropyridine-sensitive Ca channel was observed primarily between action potentials. This second Ca pathway shows remarkably long openings at negative potentials after a series of positive prepulses. The nerve action potential and the repetitive firing work as a physiological Ca channel facilitation mechanism. Therefore, we suggest that this novel Ca conductance provides inward current, between two consecutive action potentials, able to modulate the frequency of neuronal bursts. Received: 3 August 1995/Received after revision: 9 October 1995/Accepted: 10 October 1995     

Selected pool of peptides from ESAT-6 and CFP-10 proteins for detection of Mycobacterium tuberculosis infection

We have validated a new test for detecting Mycobacterium tuberculosis infection. A pool of synthetic peptides derived from ESAT-6 and CFP-10 proteins was used to detect the number of specific gamma interferon-producing T cells by means of an enzyme-linked immunospot assay. Sixty-eight individuals positive for M. tuberculosis infection, either human immunodeficiency virus-seropositive or -seronegative, were studied. The test results were highly specific (87.5%) and sensitive (93.1%), more so than a classical lymphoproliferative assay (specificity and sensitivity of 77.27%), opening new possibilities for diagnosis and screening of tuberculosis. Moreover, the test allowed us to distinguish individuals infected with M. tuberculosis from those vaccinated with BCG.     

A study of cellular immunity in newborns after prevention of respiratory distress syndrome (RDS)

Cellular immune responsiveness against infections was evaluated in four groups of newborns. The first group was composed of preterm newborns whose mothers had received betamethasone for prevention of RDS, the second group of preterm newborns whose mothers had received ambroxol for prevention of RDS, the third group of preterm newborns whose mothers had not received any drug enhancing surfactant production, and the fourth group were healthy-term infants. A reduction of OKT4+ cells and functional deficits of neutrophils were found in preterm infants born to mothers treated with steroids, whereas no functional abnormalities of immune-competent cells were observed in preterm infants born to mothers treated with ambroxol.     

New options in breast reconstructive surgery: Alternatives to the latissimus dorsi musculocutaneous flap

Transposition of the latissimus dorsi musculocutaneous flap is still considered by most authors a first-choice technique for breast reconstruction. However, the aesthetic drawbacks of the technique are significant: In our experience the posterior scar and the patchlike skin island are of concern to more than 30% of patients. Recent alternatives have sharply reduced the use of the latissimus dorsi myocutaneous flap as our first-choice technique. The utilization of a latissimus dorsi muscular flap in association with submuscular placement of a tissue expander is now our favorite technique for the majority of patients: Residual scarring is insignificant since the whole muscle can be raised through a 5–7-cm-long, S-shaped incision placed along the anterior border of the latissimus dorsi. The results obtained in a group of 35 patients demonstrate that the final results of the procedure in terms of shape and projection of the reconstructed breasts are absolutely similar to those obtained using the latissimus dorsi musculocutaneous flap. However, in patients with heavy body structure and large contralateral breast, satisfactory symmetry and a natural-looking reconstructed breast are obtained more effectively by transposition of a rectus abdominis myocutaneous flap. The precautions to be taken in order to make the procedure suitable for overweight patients are described and the results are discussed.     

New options in breast reconstructive surgery: alternatives to the latissimus dorsi musculocutaneous flap

Transposition of the latissimus dorsi musculocutaneous flap is still considered by most authors a first-choice technique for breast reconstruction. However, the aesthetic drawbacks of the technique are significant: In our experience the posterior scar and the "patchlike" skin island are of concern to more than 30% of patients. Recent alternatives have sharply reduced the use of the latissimus dorsi myocutaneous flap as our first-choice technique. The utilization of a latissimus dorsi muscular flap in association with submuscular placement of a tissue expander is now our favorite technique for the majority of patients: Residual scarring is insignificant since the whole muscle can be raised through a 5-7-cm-long, S-shaped incision placed along the anterior border of the latissimus dorsi. The results obtained in a group of 35 patients demonstrate that the final results of the procedure in terms of shape and projection of the reconstructed breasts are absolutely similar to those obtained using the latissimus dorsi musculocutaneous flap. However, in patients with heavy body structure and large contralateral breast, satisfactory symmetry and a natural-looking reconstructed breast are obtained more effectively by transposition of a rectus abdominis myocutaneous flap. The precautions to be taken in order to make the procedure suitable for over-weight patients are described and the results are discussed.     

Thermoresponsive Reversible Unimer Micelles of Amphiphilic Fluorinated Copolymers

Amphiphilic fluorinated copolymers PEGMAx-co-FAy and TEGMAx-co-FAy are prepared by activators regenerated by electron transfer atom transfer radical polymerization (ARGET-ATRP). All polymers present a reversible thermoresponsive lower critical solution temperature-type behavior, and a cloud point temperature (T_c) in the range of 30–60 °C strictly dependent on the length of the oxyethylene side chain, the content of the hydrophobic counits, and the concentration of the solution. Combined small angle X-ray scattering (SAXS) and dynamic light scattering measurements are used to study the self-assembly behavior in water, organic solvents (tetrahydrofuran [THF] and dimethylformamide [DMF]), and a fluorinated solvent (hexafluorobenzene [HFB]). SAXS confirms the formation of compact-globular single-chain self-folded unimer micelles in water below T_c, which generally presents small hydrodynamic diameters (D_h ≤ 8 nm) as a result of the folding of the hydrophobic perfluorohexylethyl acrylate counits. The copolymers are also able to form reverse unimer micelle in HFB. The copolymers are not able to self-assemble in unimer micelles in THF or DMF solutions, in which they adopt conventional random coil conformations.     

The use of chemical restraint in helicopter transport

Introduction: Helicopter transport of the combative patient is a major safety hazard facing air medical teams. Although physical restraints alone are helpful, the addition of chemical restraint (CR) often is necessary to control these patients while in flight.

Methods: A survey was conducted to determine the current practices of using nonparalyzing CR in air medical transport programs nationwide. The survey consisted of 24 questions on the use of CR during transport. Each U.S. program belonging to the Association of Air Medical Services was contacted by telephone, and a flight nurse or paramedic provided answers based on personal experience and statistics compiled by his or her individual program.

Results: Of the 100 programs responding, benzodiazepines were used most commonly to control agitation with 51% using midazolam. Patients with a head injury required CR more frequently than any other condition (73%). Crews flying larger aircraft reported less need for CR. A physician order was required by only 30% of the programs, but delays infrequently endangered the patient (2%). Only 7% of the responding programs had a patient whose condition deteriorated because of CR.

Conclusion: CR is necessary in air medical transport. Most programs use short-acting benzodiazepines. Crews in smaller aircraft use CR more frequently, and head injury is the most common condition requiring such restraint.