Time-resolved,light scattering measurements of cartilage and cornea denaturation due to free electron laser radiation

Light scattering is used to monitor the dynamics and energy thresholds of laser-induced structural alterations in biopolymers due to irradiation by a free electron laser (FEL) in the infrared (IR) wavelength range 2.2 to 8.5 microm. Attenuated total reflectance (ATR) Fourier-transform IR (FTIR) spectroscopy is used to examine infrared tissue absorption spectra before and after irradiation. Light scattering by bovine and porcine cartilage and cornea samples is measured in real time during FEL irradiation using a 650-nm diode laser and a diode photoarray with time resolution of 10 ms. The data on the time dependence of light scattering in the tissue are modeled to estimate the approximate values of kinetic parameters for denaturation as functions of laser wavelength and radiant exposure. We found that the denaturation threshold is slightly lower for cornea than for cartilage, and both depend on laser wavelength. An inverse correlation between denaturation thresholds and the absorption spectrum of the tissue is observed for many wavelengths; however, for wavelengths near 3 and 6 microm, the denaturation threshold does not exhibit the inverse correlation, instead being governed by heating kinetics of tissue. It is shown that light scattering is useful for measuring the denaturation thresholds and dynamics for different biotissues, except where the initial absorptivity is very high.     

Leukocyte density and pro-inflammatory cytokine expression in human fetal membranes,decidua, cervix and myometrium before and during labour at term

Accumulating evidence suggests that human parturition represents an inflammatory process. Leukocytes are known to infiltrate uterine tissues but the exact timing, nature and quantity of these cells has not been formally characterized. We have previously demonstrated an apparent increase in pro-inflammatory cytokines within tissues of the labouring uterus. The aims of this study were to quantify and compare the leukocyte subpopulations before and during labour in fetal membranes, decidua and cervix and to quantify and compare mRNA expression of interleukin-1beta (IL-1beta), IL-6, IL-8 and tumour necrosis factor-alpha in myometrium, cervix, chorio-decidua and amnion. Biopsies of each of these tissues were obtained from pregnant women delivered by Caesarean section before and after the onset of spontaneous labour at term. Subpopulations of leukocytes were identified using immunohistochemistry and cytokine mRNA expression was quantified using Northern analysis. We found that parturition was associated with a significant increase in IL-1beta, IL-6 and IL-8 mRNA expression in cervix and myometrium, IL-6 and IL-8 mRNA expression in chorio-decidua and IL-1beta and IL-8 mRNA expression in amnion. Histological analysis demonstrated that leukocytes (predominantly neutrophils and macrophages) infiltrate the uterine cervix coincident with the onset of labour. These data lend further support to the hypothesis that labour is an inflammatory process.     

Adaptive immune response of Vgamma2Vdelta2 T cells: a new paradigm

The role of gammadelta T cells in adaptive immunity remains uncertain. Recent studies have demonstrated that a unique subset of gammadelta T cells in primates can mount adaptive immune responses during mycobacterial infections. This Review discusses notable similarities and differences in adaptive immune responses between non-peptide-specific gammadelta T cells and peptide-specific alphabeta T cells, and discusses both the molecular basis for gammadelta T-cell responses and potential functions of these enigmatic cells.     

A markup language for electrocardiogram data acquisition and analysis (ecgML)

Background  

The storage and distribution of electrocardiogram data is based on different formats. There is a need to promote the development of standards for their exchange and analysis. Such models should be platform-/ system- and application-independent, flexible and open to every member of the scientific community.     

Iron,haptoglobin phenotype,and HIV-1 viral load: a cross-sectional study among pregnant Zimbabwean women

BACKGROUND: Viral load is a determinant of HIV-1 progression and transmission. Iron status and the phenotype of haptoglobin, a heme-binding acute phase reactant, may be determinants of viral load. We aimed to describe the effect of iron status, haptoglobin phenotype (Hp), and other predictors on HIV-1 viral load. METHODS: Based on a cross-sectional study among 1669 antenatal care attenders (22-35 weeks) in Zimbabwe, 526 (31.5%) were found to be HIV infected. The role of season, age, gravidity, gestational age, malaria parasitemia, Hp, and elevated serum alpha(1)-antichymotrypsin (ACT) as well as serum ferritin, folate, retinol, and beta-carotene on HIV viral load among the 526 HIV-infected women was assessed using multiple linear regression analysis. RESULTS: The distribution of Hp 1-1 (32%), Hp 2-1 (48%), and Hp 2-2 (20%) was not different from that of 53 uninfected women. Mean viral load was 3.85 log(10) (95% CI: 3.77-3.93) genome equivalents (geq)/mL, ranging from 3.77 (95% CI: 3.64-3.90) geq/mL in women with Hp 1-1 to 4.05 (95% CI: 3.81-4.21) geq/mL in women with Hp 2-2. With elevated serum ACT controlled for, women with Hp 2-2 had viral loads twice (95% CI: 1.4-4.0, p =.002) that of women with Hp 1-1, whereas those with serum ferritin <6 micro g/L had viral loads less than one third (95% CI: 0.13-0.53, p =.013) that of women with serum ferritin >24 micro g/L. Viral loads were also higher in women enrolled in the early rainy season compared with the dry season, in gravidae 4+ compared with gravidae 1 through 3, and in those with moderately elevated compared with low serum alpha(1)-antichymotrypsin, but neither age, gestational age, serum folate, serum retinol, nor serum beta-carotene were predictors. CONCLUSION: Storage iron, Hp 2-2, and elevated ACT are independent positive predictors of HIV-1 viral load. The positive relationship between serum ferritin and viral load was not the result of an acute phase response or iron accumulation with advanced HIV infection. A possible detrimental role of iron in HIV infection would have serious public health implications.     

Glycosaminoglycan profiles of myxomatous mitral leaflets and chordae parallel the severity of mechanical alterations

OBJECTIVES: This biochemical study compared the extracellular matrix of normal mitral valves and myxomatous mitral valves with either unileaflet prolapse (ULP) or bileaflet prolapse (BLP). BACKGROUND: Myxomatous mitral valves are weaker and more extensible than normal valves, and myxomatous chordae are more mechanically compromised than leaflets. Despite histological evidence that glycosaminoglycans (GAGs) accumulate in myxomatous valves, previous biochemical analyses have not adequately examined the different GAG classes. METHODS: Leaflets and chordae from myxomatous valves (n = 41 ULP, 31 BLP) and normal valves (n = 27) were dried, dissolved, and assayed for deoxyribonucleic acid, collagen, and total GAGs. Specific GAG classes were analyzed with selective enzyme digestions and fluorophore-assisted carbohydrate electrophoresis. RESULTS: Biochemical changes were more pronounced in chordae than in leaflets. Myxomatous leaflets and chordae had 3% to 9% more water content and 30% to 150% higher GAG concentrations than normal. Collagen concentration was slightly elevated in the myxomatous valves. Chordae from ULP had 62% more GAGs than those from BLP, primarily from elevated levels of hyaluronan and chondroitin-6-sulfate. CONCLUSIONS: The GAG classes elevated in the myxomatous chordae are associated with matrix microstructure and elastic fiber deficiencies and may influence the hydration-related "floppy" nature of these tissues. These abnormalities may be related to the reported mechanical weakness of myxomatous chordae. The biochemical differences between ULP and BLP confirm previous mechanical and echocardiographic distinctions.     

A randomized,controlled trial comparing long-term and short-term exercise in patients with chronic obstructive pulmonary disease

PURPOSE: To compare the effects of short-term (3 months) and long-term (18 months) involvement in an exercise program on self-reported disability and physical function in patients with chronic obstructive pulmonary disease (COPD). METHODS: A total of 140 patients with COPD were studied in a randomized, single-blinded clinical trial. Self-reported disability and physical function were assessed using a 21-item questionnaire, a 6-minute walk, timed stair climb, and an overhead task. RESULTS: At the completion of the trial, participants in the long-term intervention reported 12% less disability than those in the short-term intervention (adjusted mean with 95% confidence interval, 1.53 (1.43-1.63) versus 1.71 (1.61 to 1.81) units, respectively; P=.016), walked 6% farther during 6-minutes (1,815.0 [1,750.4-1,879.6] vs 1,711.5 [1,640.7-1,782.3] feet, respectively), climbed steps 11% faster (11.6 [11.0-12.2] vs 12.9 [12.3-13.5] seconds, respectively), and completed an overhead task 8% faster (46.8 [44.4-49.2] vs 50.4 [47.8-53.0] seconds, respectively) than those in the short-term intervention. CONCLUSION: An 18 month exercise program results in greater improvements in self-reported disability and physical function in patients with COPD when compared with a 3-month exercise program. As such, long-term exercise should be recommended for all patients with COPD.     

Sociodemographic diversity and behavioral medicine

The broad array of economic and cultural diversity in the U.S. population correlates with and impacts on the study of behavioral aspects of health. The purpose of this article was to provide a selective overview of behavioral medicine research on sociodemographically diverse populations, with a focus on ethnicity, gender, and socioeconomic status. Suggestions are provided with regard to methodological refinement of research and insights into possible future directions in behavioral medicine research on ethnically and economically diverse populations.     

The effect of various infertility treatments on the risk of preterm birth

BACKGROUND: The high incidence of preterm birth (<37 weeks gestation) is a major concern in assisted reproductive technology. The objective of this study was to compare the risk of preterm birth from singleton pregnancies following either low technology treatment (intrauterine insemination and donor insemination) or high technology treatment (IVF, ICSI and gamete intra-Fallopian transfer) with that of naturally conceived pregnancies. METHODS: Three cohorts of pregnancies resulting from either low or high technology treatment or from natural conception were included in the study. A number of potential risk factors were adjusted for. RESULTS: The incidence of very preterm birth (<32 weeks of gestation) was not significantly increased in the low technology treatment group (1.0 versus 1.3% in controls) but was significantly higher in the high technology treatment group (5.2%, P < 0.001). In spontaneous, elective Caesarean section (CS) and induced delivery onset, the risk of preterm birth increased gradually from the controls to the low technology treatment group to the high technology treatment group, while for an emergency CS the risk of preterm birth was very high in both treatment groups. CONCLUSIONS: The overall incidence of preterm birth increased significantly from the controls to the low technology treatment group and to the high technology treatment group. Logistic regression analysis showed that younger and older age, previous perinatal death and emergency CS were associated with an increased risk, while a previous live birth reduced the risk. The length of the infertile period did not seem to affect the risk in any of the treatment groups.