Effects of recombinant human interleukin 7 on T-cell recovery and thymic output in HIV-infected patients receiving antiretroviral therapy: results of a phase I/IIa randomized, placebo-controlled, multicenter study.

BACKGROUND: The immune deficiency of human immunodeficiency virus (HIV) infection is not fully corrected with ARV therapy. Interleukin-7 (IL-7) can boost CD4 T-cell counts, but optimal dosing and mechanisms of cellular increases need to be defined. METHODS: We performed a randomized placebo-controlled dose escalation (10, 20 and 30 µg/kg) trial of 3 weekly doses of recombinant human IL-7 (rhIL-7) in ARV-treated HIV-infected persons with CD4 T-cell counts between 101 and 400 cells/µL and plasma HIV levels <50 copies/mL. Toxicity, activity and the impact of rhIL-7 on immune reconstitution were monitored. RESULTS: Doses of rhIL-7 up to 20 µg/kg were well tolerated. CD4 increases of predominantly naive and central memory T cells were brisk (averaging 323 cells/µL at 12 weeks) and durable (up to 1 year). Increased cell cycling and transient increased bcl-2 expression were noted. Expanded cells did not have the characteristics of regulatory or activated T cells. Transient low-level HIV viremia was seen in 6 of 26 treated patients; modest increases in total levels of intracellular HIV DNA were proportional to CD4 T-cell expansions. IL-7 seemed to increase thymic output and tended to improve the T-cell receptor (TCR) repertoire in persons with low TCR diversity. CONCLUSIONS: Three weekly doses of rhIL-7 at 20 µg/kg are well tolerated and lead to a dose-dependent CD4 T-cell increase and the broadening of TCR diversity in some subjects. These data suggest that this rhIL-7 dose could be advanced in future rhIL-7 clinical studies. CLINICAL TRIALS REGISTRATION: NCT0047732.

Non reciprocal writing and chirality in femtosecond laser irradiated silica.

We ascertain by measuring the surface topography of a cleaved sample in which damage lines have been written in volume by scanning with a femtosecond laser, that matter shearing occur along the laser track with alternating sign (scissor or chiral effect). We note that the shearing in the head of the laser tracks change its sign with the change in scanning direction (pen effect or non reciprocal writing). We also show that nanostructures in the head are nano-shearing, with all the same sign whatever the direction of writing may be. We suggest that symmetries revealed by the shearing mimic the laser induced electron plasma density structures and inform on their unusual symmetries induced by the laser beam structures.

Migration of contaminants by gas phase transfer from carton board and corrugated board box secondary packaging into foods.

The gas phase transfer of substances from carton board (CB) and corrugated box board (CBB) through intervening layers to foods was studied. Substances covering a boiling point range of 252-425 degrees C and a range of polarities were incorporated into CB and CBB secondary packaging. Benzophenone was present in some CB materials. Where it was not already present in CB or CBB secondary packaging, it was deliberately incorporated for transfer studies. Transfer of substances was measured in nine foodstuff types stored in the secondary packaging at ambient and sub-ambient temperature. The foods were packaged in primary packaging materials that would be used in retail. Two food types were packed and stored in both single- and multipack formats. Foods were sampled at 0, 10, 30, 90 and 200 days and analysed by gas chromatography-mass spectrometry after high-performance size exclusion chromatography clean-up. Percentage transfer was between 0 and 100%. The overall trends were increased transfer of substances with increased storage time; a more rapid transfer of the more volatile substances compared with the less volatile ones and higher levels of transfer of the more volatile substances. No transfer of diheptyl phthalate (DHP) (bp 425 degrees C) as an incorporated substance was detected to any foods over the test period. The presence of an additional layer of packaging (multipack versus single pack) was shown to reduce transfer up to fourfold over 200 days and to increase the lag period for transfer. In terms of slowing transfer, metallized PP/PP laminate proved a more effective barrier than PP which was more effective than paper. It is postulated that there is a cut-off threshold for transfer at ambient and sub-ambient temperatures. Substances that are less volatile than the cut-off are anticipated not to transfer from secondary packaging to foods stored for up to 200 days, where the substances are present in the packaging at or below the levels tested in this study (up to 1 mg dm-2). In this study the volatility cut-off threshold lay between that of 2,2-dimethoxyphenylacetophenone (2,2-DMPAP) (an incorporated substance with bp 352 degrees C) and DHP. Ideally, the cut-off threshold should be expressed in terms of vapour pressure in the packaging material. In practical terms, it may be more appropriate to express as partition coefficient as this is simpler to determine experimentally.

Quantification of T cell receptor rearrangement excision circles to estimate thymic function: an important new tool for endocrine-immune physiology.

Although the thymus constitutes a target organ for most protein and steroid hormones, it has been quite difficult to determine the precise control exerted in vivo by the endocrine system upon thymic function. The biological role of the thymus is to ensure the generation of a diversified population of peripheral T cells able to respond to non-self-antigens but nevertheless tolerant to self-antigens. For a long time, thymic function could not be monitored, as a consequence of the absence of adequate technology to differentiate recent thymic emigrants from naive T cells. The generation of T cell receptor (TCR) diversity occurs in the thymus through recombination of gene segments encoding the variable parts of the TCR alpha and beta chains. During these processes, by-products of the rearrangements are generated in the form of TCR excision circles (TRECs). As these molecules are lost upon further cell division, their quantification is actually considered as a very valuable tool to estimate thymic function. The most appropriate TREC is deltaRec-Psi(J)alpha TREC or signal joint TREC resulting from deltaRec-Psi(J)alpha rearrangement (TCRD deletion) that occurs late during thymopoiesis, before V(alpha)-J(alpha) rearrangement. Here we describe how TREC quantification is a powerful and reliable method to evaluate the impact of hormones and endocrine disorders upon thymic function.

Persistent polyclonal B-cell lymphocytosis: further evidence for a genetic disorder associated with B-cell abnormalities.

Persistent polyclonal B-cell lymphocytosis (PPBL) is an intriguing disorder diagnosed predominantly in women, usually cigarette smokers, characterized by an increase in the number of polyclonal B lymphocytes. Abnormality of the B-cell population is also evidenced by the presence of multiple bcl-2/Ig gene rearrangements and the finding of an additional long arm chromosome 3q+ (i3)(q10) within a significant proportion of B cells. The physiopathology of PPBL is unknown but its association with the HLA DR7 phenotype suggests a possible genetic disorder. To further determine whether PPBL has a genetic predisposition, we have undertaken an extensive study in a large family of a patient diagnosed with PPBL. Three individuals among the first-degree relatives presented all the criteria for a diagnosis of PPBL. A slight increase in serum IgM without evidence of B-cell proliferation was shown in two additional siblings. Multiple bcl-2/Ig gene rearrangements, a typical feature of PPBL, were identified in 8/10 individuals among first-degree relatives. A statistically significant association was found between the presence of these rearrangements and of a paternal HLA haplotype. We conclude that PPBL has a familial occurrence suggesting an underlying genetic defect. The development of the complete syndrome probably relies on unidentified additional co-factors.

Detection of T cell receptor circles (TRECs) as biomarkers for de novo T cell synthesis using a quantitative polymerase chain reaction-enzyme linked immunosorbent assay (PCR-ELISA).

Currently, phenotypic markers that distinguish between recent thymic emigrants/de novo T cells and the rest of the peripheral T cell pool are lacking. This distinction is critical in studies aimed at evaluating immune reconstitution following intensive chemotherapy, in immunodeficiency-related therapies, or in the elucidation of the kinetics of thymic function. During V(D)J T cell receptor rearrangement, DNA extrachromosomal excision products are generated. These products, known as T cell receptor excision circles (TRECs), are not replicated during mitosis and are thus diluted with each round of cell division. Therefore, TRECs can be used as an indicator of recent thymic emigrants. Thus far, quantitative competitive-polymerase chain reaction (QC-PCR) and real time PCR were used to measure TREC levels. However, QC-PCR relies on radioactivity, is cumbersome when processing many samples at once and the cost of real time PCR does not make it a viable option for many laboratories. We describe here the development of a quantitative PCR-ELISA method for the measurement of coding joint TRECs generated from ValphaJalpha recombination. Our assay is ultra sensitive, relies on biotin labeling rather than radioactivity, is based on a 96-well format making multiple process sampling relatively easy, and is cost effective. Using this PCR-ELISA method, we evaluated thymic output among 22 normal subjects, ranging in age from 22-53 years, and among HIV-infected individuals following highly active antiretroviral therapy (HAART). We demonstrate that an inverse relationship exists between TREC levels and aging in normal individuals and that, among some HIV patients, HAART treatment leads to enhanced thymic output. Our assay has direct relevance in projects examining normal and abnormal thymic function and in immune reconstitution studies.

Direct evidence for thymic function in adult humans.

The understanding of human thymic function and evaluation of its contribution to T cell homeostasis are matters of great importance. Here we report the development of a novel assay to quantitate the frequency and diversity of recent thymic emigrants (RTEs) in the peripheral blood of humans. Such cells were defined by the presence of T cell receptor (TCR) rearrangement deletion circles (DCs), episomal byproducts of TCR-beta V(D)J rearrangement. DCs were detected in T cells in the thymus, cord blood, and adult peripheral blood. In the peripheral blood of adults aged 22 to 76 years, their frequency was highest in the CD4(+)CD45RA(+) CD62L(+) subpopulation of naive T cells. TCR DCs were also observed in other subpopulations of peripheral blood T cells, including those with the CD4(+)CD45RO(-)CD62L(+) and CD4(+)CD45RO(+)CD62L(+) phenotypes. RTEs were observed to have more than one Vbeta rearrangement, suggesting that replenishment of the repertoire in the adult is at least oligoclonal. These results demonstrate that the normal adult thymus continues to contribute, even in older individuals, a diverse set of new T cells to the peripheral circulation.

Incidence of venographically proved deep vein thrombosis after knee arthroscopy.

BACKGROUND: Deep vein thrombosis is a common, important complication of major orthopedic surgery, particularly knee arthroplasty. Knee arthroscopy is performed more frequently and in younger patients than knee arthroplasty. However, the true risk of deep vein thrombosis in patients who undergo this procedure is unknown. OBJECTIVE: To determine the incidence of deep vein thrombosis after knee arthroscopy in a large cohort of patients. METHODS: Consecutive patients scheduled for knee arthroscopy were eligible for the study. Enrolled study patients received no thromboprophylaxis. They were discharged home the day of surgery and underwent unilateral contrast venography approximately 1 week after their operation. The primary outcome measure was the incidence of venous thromboembolism. Risk factors for deep vein thrombosis were evaluated. RESULTS: Among the 184 patients who had adequate venography, deep vein thrombosis was detected in 33 (17.9%; 95% confidence interval, 12.7%-24.3%). Of these, 9 were proximal (4.9%; 95% confidence interval, 2.3%-9.1%). No patient died and no patient presented with clinically suspected pulmonary embolism. Of 33 patients, only 20 (60.6%) with deep vein thrombosis had symptoms while 13 (39.4%) were asymptomatic. The risk of deep vein thrombosis was significantly higher among patients who had a tourniquet applied for more than 60 minutes. CONCLUSIONS: The results of our study demonstrate that 17.9% of patients develop deep vein thrombosis after knee arthroscopy (most being either proximal or extensive). It is reasonable to perform a randomized trial to determine whether the incidence of deep vein thrombosis can be safely reduced in patients undergoing knee arthroscopy.

Gender differences in attitudes toward alcohol, tobacco, and other drugs.

A number of differences exist between men and women in use patterns and risk factors for substance abuse. In recent years these differences have received increased attention; however, gender-related attitudes toward substance abuse need additional study. This study examines gender-related differences in beliefs about the causes of the abuse of alcohol, tobacco, and other drugs; the power of various substances of abuse; the prevalence of substance use; and the effectiveness of various interventions. Women were more likely to attribute causality to biological or environmental factors, to perceive drugs as more powerful, to perceive a higher incidence of substance abuse, and to believe prevention and treatment were more effective. Therefore, prevention, assessment, and treatment programs should be designed differently for women than for men.

Vitamin E prevents oxidative modification of brain and lymphocyte band 3 proteins during aging.

Antioxidants may play an important role in preventing free radical damage associated with aging by interfering directly in the generation of radicals or by scavenging them. We investigated the effects of a high vitamin E and/or a high beta-carotene diet on aging of the anion transporter, band 3, in lymphocytes and brain. The band 3 proteins function as anion transporters, acid base regulators, C02 transporters, and structural proteins that provide a framework for membrane lipids and that link the plasma membrane to the cytoskeleton. Senescent cell antigen (SCA), which terminates the life of cells, is a degradation product of band 3. This study was conducted as a double-blind study in which eight groups of middle-aged or old mice received either high levels of beta-carotene and/or vitamin E or standard levels of these supplements in their diets. Anion transport kinetic assays were performed on isolated splenic lymphocytes. Immunoreactivity of an antibody that recognizes aging changes in old band 3 preceding generation of SCA was used to quantitate aged band 3 in brain tissue. Results indicate that vitamin E prevented the observed age-related decline in anion transport by lymphocytes and the generation of aged band 3 leading to SCA formation. beta-Carotene had no significant effect on the results of either assay. Since increased aged band 3 and decreased anion transport are initial steps in band 3 aging, which culminates in the generation of SCA and cellular removal, vitamin E prevents or delays aging of band 3-related proteins in lymphocytes and brain.

Posttranslational changes in band 3 in adult and aging brain following treatment with ergoloid mesylates, comparison to changes observed in Alzheimer's disease.

Band 3, the most heavily used anion transport system in vertebrates, ages as cells and tissues age. Posttranslational changes in band 3 in adult and aging brain were investigated following treatment with ergoloid mesylates and compared to changes observed in Alzheimer's disease (AD). The study was conducted in a double blind fashion and was decoded only after the study was completed. The following posttranslational changes in brain band 3 occur with age: increased breakdown of band 3; decreased phosphorylation; and decreased anion transport. Autoantibodies to senescent cell antigen (SCA) synthetic peptides residue 538-554 and 812-827 increase with age, but antibodies to the former peptide are significantly reduced in ergoloid mesylate treated old mice. This is a critical transport region of band 3. Results showed the aged/altered band 3 increased in Alzheimer's disease (AD) as determined by quantitative antibody binding. Ergoloid mesylates altered the age-related posttranslational changes as follows: the observed age-related decrease in brain band 3 was partially reversed and anion transport was increased. This is consistent with the data indicating decreased autoantibodies to a critical anion transport segment of band 3. Aging appears to result in damage to a critical transport region of the anion transporter which is reflected by decreased anion transport, increased breakdown, alteration of the molecule itself, and an increase in autoantibodies to the region. Ergoloid mesylates seem to protect against this damage.

Molecular basis of human band-3 mutation associated with increased anion transport.

Band 3, the anion transporter, is a ubiquitous protein. It is present in brain and all other tissues. Not only is band 3 present in cell membranes, but also in nuclear, Golgi, and mitochondrion membranes. Band 3 is involved in respiration, acid-base balance, and is the major structural protein linking the plasma membrane to the cytoskeleton. Thus, alterations/mutations in the transport segment of the band-3 molecule might be expected to be of major importance. We discovered and sequenced a mutation of band 3, high-transport band 3 (HTbd3), that exhibits anion transport that is 2-3 time above normal. Anion transport studies of the family members revealed that red cells from the proposita, one of two siblings, and both parents had abnormally increased anion transport (increased Vmax). We used synthetic peptides of band 3 to help localize the change along the band-3 molecule. Results suggest that high-transport band 3 is altered in or near residue 869-883. This places the alteration toward the carboxyl terminal of band 3. cDNA sequencing demonstrated that the mutation was a proline to leucine at residue 868. A peptide was synthesized corresponding to residues 853-870 for testing in the anion transport inhibition assay. This peptide significantly inhibited anion transport (p < or = 0.001) indicating that it is an anion transport/binding region of band 3. Thus, DNA technology confirms the validity of the anion transport inhibition assay for localizing transport regions. Glucose transport is decreased in affected individuals. The HTbd3 mutation appears benign as determined by the red cell aging panel. IgG binding, creatinine, and glyceraldehyde-3-phosphate dehydrogenase are normal. Our studies indicate that the most rapid and sensitive techniques for detecting band-3 alterations are polyacrylamide gel electrophoresis, IgG binding, and anion transport studies. This is the only mutation of band 3 discovered to date the affects the transmembrane, anion transport region of band 3.

Burnout in gerontological social work.

Although burnout in various fields of social work has been explored in some depth, there is a dearth of research on the gerontological social worker's experience with burnout. This article reports a national survey of burnout among 1,196 social workers who work with elderly people and who belong to either the National Association of Social Workers or the Gerontological Society of America. The extent to which these social workers experience the three components of burnout (emotional exhaustion, depersonalization, and personal accomplishment) is reported. The significant client, organizational, and personal factors associated with burnout among gerontological social workers are identified, and implications for social work practice are discussed.

A study of 185 foster children 5 years after placement.

This study's findings are similar to those of other studies. The majority of children who enter foster care return to their families within a relatively short time. A small group, because of the severity of their problems or those of their parents, need extended care. This group of children, over time, form the hard core of foster care placements. Our findings also bear out those of others that the foster care experience is a relatively stable one for children, with the majority having one or two placements while in care. Clearly, the need for and use of foster care is frequently misunderstood. The methodology used in research studies has gradually improved, adding to objective knowledge about this aspect of the child welfare system. Longitudinal studies, such as Jenkins [1967], Fanshel and Shinn [1978], and the one reported here, point to the need for deeper, more refined studies that examine not only the going and coming of children in foster care but the professional service component that can make foster care a constructive experience for children placed in it. Meyer issued an intelligent and timely challenge to the field of child welfare to give up "debates about permanency" and, if it is not too late, to "retrieve child welfare from the control of lawyers and MBAs" [1984: 499]. If the profession of social work can more clearly define the components of foster care service and can differentiate among the children needing care those who can best be served by this type of placement, then the field will be well on its way to offering an appropriate service for certain children. Attempts to denigrate a potentially helpful service for needy children simply destroy one aspect of a complex system. A wide range of services is necessary to serve all children appropriately. Without this kind of continuum, children are more likely to receive inappropriate services and to be placed at risk.

Study of plating efficiency of bacteriophages of thermophilic lactic acid bacteria on different media.

The qualitative and quantitative abilities of phages of 13 strains of thermophilic lactic bacteria (lactobacilli and streptococci) to produce plaques on six different media were studied. The influence of the addition of calcium on the one hand, and of incubation conditions (aero-anaerobiosis), on the other hand, was also examined. For the phages of lactobacilli, the best results were obtained with the medium of de Man, Rogosa, and Sharpe (1960), whereas for the phages of streptococci the medium of Hogg and Jago (1970) appeared to be the best. Calcium and incubation conditions play a role which is variable in importance, but rarely negligible.

[Observation of bacteriophages in wine (author's transl)]. / Mise en evidence de bactériophages dans le vin

Electron microscopic examination of samples of Swiss wine, collected during the malolactic fermentation, revealed the presence of bacteriophages of three different morphological types. It is interesting to note that these phages have been found in a product whose pH is lower than 3.5.