Biomedical subjects

M Bell

Publications and source records attributed to M Bell.

At least 19 recordsLinked to original sources

PubMed2003

Exercise for osteoarthritis of the hip or knee.

BACKGROUND: Biomechanical factors, such as reduced muscle strength and joint mal-alignment, have an important role in the initiation and progression of osteoarthritis (OA) of the hip or knee. Currently, there is no known cure for OA, however, disease-related factors, such as impaired muscle function and reduced fitness, are potentially amenable to therapeutic exercise. OBJECTIVES: To determine whether land-based therapeutic exercise is beneficial for people with OA of the hip or knee in terms of reduced joint pain, improved physical function and/or the patient's global assessment of therapeutic effectiveness. SEARCH STRATEGY: Five databases (the Cochrane Controlled Trials Register, the Cochrane Musculoskeletal Group Trials Register, MEDLINE, CINAHL, PEDro) were searched up until November 2002. SELECTION CRITERIA: All randomized controlled trials comparing some form of land-based therapeutic exercise (as opposed to exercises conducted in the water) with a non-exercise group. DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted data and assessed methodological quality. All analyses were conducted on continuous outcomes. MAIN RESULTS: Only 2 studies totaling about 100 participants, could potentially provide data on people with OA of the hip. However, for OA of the knee, 17 included studies provided data on 2562 participants. For pain, combining the results revealed a beneficial treatment effect (standardised mean difference) of.39 (95% confidence interval (CI).30 -.47) while for self-reported physical function a beneficial treatment effect of.31 (95% CI.23 -.39). Group format programs appeared to be as effective as treatments provided on a one-to-one basis. The results were sensitive to various aspects of study design methodology. REVIEWER'S CONCLUSIONS: Land-based therapeutic exercise was shown to reduce pain and improve physical function for people with OA of the knee. There were insufficient data to provide useful guidelines on optimal exercise type or dosage. Supervised exercise classes appeared to be as beneficial as treatments provided on a one-to-one basis.

Exercise Therapy↗

PubMed2003

Cognitive remediation of working memory deficits: durability of training effects in severely impaired and less severely impaired schizophrenia.

OBJECTIVE: To determine whether augmenting work therapy (WT) with neurocognitive enhancement therapy (NET) yields greater improvement in working memory performance than WT alone and whether there is an interaction with severity of impairment. METHOD: A total of 102 participants with schizophrenia or schizoaffective disorder were categorized as severely or less severely cognitively impaired and randomly assigned to receive NET + WT or WT alone. NET consisted of cognitive training exercises in attention, memory, executive function, and social information processing, and WT was a 6-month work program. RESULTS: Comparison on Digits Backwards from intake to follow-up revealed significantly greater improvement for participants receiving NET + WT, but there was no interaction with severity group. Follow-up 6 months after training showed that training effects endured. CONCLUSION: NET + WT improved working memory for most participants regardless of impairment severity. Intensity and duration of training may have contributed to duration of effects. Findings support continued exploration of cognitive remediation.

Adult↗

PubMed2003

In vitro evaluation of novel low abrasive air polishing powders.

AIM OF THE STUDY: Though efficient in stain and plaque removal, air polishing is highly abrasive on root cementum or dentin even if working parameters are adjusted to minimize damage. As abrasiveness is also influenced by the physical properties of the powders used, the aim of the study was to evaluate the safety of novel low abrasive air polishing powders in vitro. MATERIAL AND METHODS: Using four novel air polishing powders (A, B, C and D) and a standard sodium bicarbonate (NaHCO3) powder, roots of 126 extracted teeth were air polished under standardized conditions at various working parameter combinations (distance: 2 mm, 4 mm and 6 mm; powder and water setting: low, medium and high) at an angulation of 90 degrees for 20 s. Instrumentation was performed in triplicate; resulting root defects were quantified laser-optically. RESULTS: Mean defect depths after application of powders A, B, C and D were significantly lower than with standard powder (A: 17.9 +/- 10.9 micro m, B: 48.2 +/- 32.7 micro m, C: 92.5 +/- 57.9 micro m, D: 33.9 +/- 19.6 micro m, NaHCO3: 163.1 +/- 71.1 micro m) (Kruskal-Wallis test). Among the experimental powders, D was transported most reliably in the air polishing unit and allowed complete removal of disclosed plaque as assessed on freshly extracted teeth. CONCLUSION: The novel air polishing powder D is of low abrasiveness to root cementum and dentin while being effective in removing dental plaque. Thus, it may be useful for safe and efficient plaque removal on exposed root surfaces.

Air↗

PubMed2003

Root defects following air polishing.

AIM: Air-polishing devices (APDs) are highly effective in removing plaque and extrinsic staining. Their application on root surfaces, however, may result in clinically relevant substance removal, limiting the use in patients with periodontitis, where denuded root surfaces are frequently found. Therefore, the purpose of the study was to assess the influence of different working parameters on root damage and to identify those minimizing root damage. MATERIAL AND METHODS: Defect depth and defect volume after instrumentation of roots with an APD (Dentsply Prophy-Jet) using conventional NaHCO3 powder at instrumentation times of 5, 10 and 20 s, combinations of low, medium and high powder and water settings, distances of 2, 4 and 6 mm, and angulations of 45 degrees and 90 degrees were quantified laseroptically. A total of 297 roots were instrumented and parameter combinations were performed in triplicate. The influence of each working parameter on substance loss was determined by multiple regression analysis. RESULTS: Time had the greatest influence on defect volume and depth (beta-weights 0.6 and 0.57, respectively), when compared with powder setting (beta-weights 0.49 and 0.3) and water setting (beta-weights 0.28 and 0.3). Variations in distance affected defect depth (beta-weight 0.44), but not volume (beta-weight 0.04). No major differences were found at 45 degrees and 90 degrees. Various parameter combinations led to maximal defect depths of 473.5 +/- 26.2 micro m within 20 s. CONCLUSION: Root damage varies among combinations of working parameters. Using the APD with the assessed NaHCO3 powder, all parameter combinations led to substantial root damage. Thus, APDs using NaHCO3 may not be safely utilized on exposed root surfaces.

Air Abrasion, Dental↗

PubMed2003

Detection of bloodstream pathogens in a bacille Calmette-Guérin (BCG)-vaccinated pediatric population in Malawi: a pilot study.

Children in Malawi receive bacille Calmette-Guérin (BCG) vaccination within the first 3 days of life. Thus, we hypothesized that Malawian children infected with the human immunodeficiency type 1 virus (HIV-1) might be particularly vulnerable to dissemination of the BCG Mycobacterium bovis strain with which they were vaccinated. Following informed consent by parents, we studied children admitted to a Malawi general hospital during the 1998 wet and dry seasons. Blood from cohorts of acutely ill children was cultured for bacteria, including mycobacteria, and fungi, and tested for anti-HIV-1 antibodies. It was shown that non-typhi Salmonella and Escherichia coli were the predominant bloodstream pathogens during the wet and dry seasons, and that bloodstream dissemination of the BCG M. bovis strain is uncommon in HIV-1-infected children who receive the BCG vaccine.

AIDS-Related Opportunistic Infections↗

PubMed2003

A nocturnal enuresis service for a deprived inner city.

AIM: Glasgow is a city where 80% of the most deprived children in Scotland live within 20% of the overall population. Of 168,000 children in Glasgow, an estimated 5000 aged 5-15 y have primary nocturnal enuresis. The aim of this study was to establish a nocturnal enuresis service for Glasgow. METHODS: Needs assessment was performed and the incident cases were documented at school entry healthcare appraisal, at the age of 5 y. A cohort of these children was followed up at 8 y of age and symptom resolution was no better than natural remission. Parents, general practitioners, clinical medical officers and a hospital paediatrician were interviewed face-to-face about their need for a service. RESULTS: Ten of 11 general practitioners expressed a need for a specialist service. Ten school nurse-led local nocturnal enuresis clinics were established. Accommodation, funding, default and managing alarms were major problems. School nurses enjoyed extra training and quickly became skilled therapists. Two research projects highlighted that most children at first attendance did not believe they could ever be dry, which predicted outcome. Deprived families, once motivated, could successfully undertake complex behavioural therapies. CONCLUSION: A comprehensive nocturnal enuresis service begins when children stop using night nappies at the age of 3-4 y. Appropriate waterproof mattress, duvet and pillow coverings should be advocated until 5 y, when desmopressin may be helpful. For continued wetting at the age of 7 y, a local service should be led by a team of well-trained nurses using enuretic alarms.

Behavior Therapy↗

PubMed2001

Monodisperse plasticized poly(vinyl chloride) fluorescent microspheres for selective ionophore-based sensing and extraction.

A convenient method for the preparation of monodisperse, plasticized poly(vinyl chloride) particles based on an automated particle casting technique is described. The particles are made highly selective for a number of ions by doping them with ionophores and other active components, in complete analogy to thin-film or fiber-optic chemical sensors. The approach used here produces spheres of high monodispersity at a rate of approximately 20000 particles/s. The casting process is based on a reproducible polymer drop formation and precipitation process, and the particles are formed under very mild, nonreactive conditions. This allows one to conveniently incorporate known amounts of different active components into the polymers. As an initial example, the particles are doped with three optical sensing components, the sodium ionophore tert-butylcalix[4]arene tetraethyl ester, the H+-chromoionophore ETH 5294, and the anionic additive sodium tetrakis[3,5-bis(trifluoromethyl)phenyl] borate. The particles are found to be of spherical shape with a diameter of approximately 10 microm. They respond individually and selectively to sodium according to classical optode theory, as determined by fluorescence microscopy. With a RSD of 1.6%, sensing reproducibility from particle to particle is excellent. This technique may allow the development of mass-produced chemically selective microspheres on the basis of bulk extraction processes.

Algorithms↗

PubMed2001

Hierarchical self-assembly of chiral rod-like molecules as a model for peptide beta -sheet tapes, ribbons, fibrils, and fibers.

A generic statistical mechanical model is presented for the self-assembly of chiral rod-like units, such as beta-sheet-forming peptides, into helical tapes, which with increasing concentration associate into twisted ribbons (double tapes), fibrils (twisted stacks of ribbons), and fibers (entwined fibrils). The finite fibril width and helicity is shown to stem from a competition between the free energy gain from attraction between ribbons and the penalty because of elastic distortion of the intrinsically twisted ribbons on incorporation into a growing fibril. Fibers are stabilized similarly. The behavior of two rationally designed 11-aa residue peptides, P(11)-I and P(11)-II, is illustrative of the proposed scheme. P(11)-I and P(11)-II are designed to adopt the beta-strand conformation and to self-assemble in one dimension to form antiparallel beta-sheet tapes, ribbons, fibrils, and fibers in well-defined solution conditions. The energetic parameters governing self-assembly have been estimated from the experimental data using the model. The 8-nm-wide fibrils consist of eight tapes, are extremely robust (scission energy approximately 200 k(B)T), and sufficiently rigid (persistence length l(fibril) approximately 20-70 microm) to form nematic solutions at peptide concentration c approximately 0.9 mM (volume fraction approximately 0.0009 vol/vol), which convert to self-supporting nematic gels at c > 4 mM. More generally, these observations provide a new insight into the generic self-assembling properties of beta-sheet-forming peptides and shed new light on the factors governing the structures and stability of pathological amyloid fibrils in vivo. The model also provides a prescription of routes to novel macromolecules based on a variety of self-assembling chiral units, and protocols for extraction of the associated energy changes.

Models, Molecular↗

PubMed2001

The landing of the NEAR-Shoemaker spacecraft on asteroid 433 Eros.

The NEAR-Shoemaker spacecraft was designed to provide a comprehensive characterization of the S-type asteroid 433 Eros (refs 1,2,3), an irregularly shaped body with approximate dimensions of 34 x 13 x 13 km. Following the completion of its year-long investigation, the mission was terminated with a controlled descent to its surface, in order to provide extremely high resolution images. Here we report the results of the descent on 12 February 2001, during which 70 images were obtained. The landing area is marked by a paucity of small craters and an abundance of 'ejecta blocks'. The properties and distribution of ejecta blocks are discussed in a companion paper. The last sequence of images reveals a transition from the blocky surface to a smooth area, which we interpret as a 'pond'. Properties of the 'ponds' are discussed in a second companion paper. The closest image, from an altitude of 129 m, shows the interior of a 100-m-diameter crater at 1-cm resolution.

Journal Article↗

PubMed2001

Memory and executive function impairments in deficit syndrome schizophrenia.

The relationship between deficit syndrome schizophrenia, as determined by the Schedule for the Deficit Syndrome, and impairments in memory and executive function was investigated by administering the Wisconsin Card Sorting Test, the Wechsler Adult Intelligence Test, and the Wechsler Memory Scales to outpatients with deficit (n=33) and non-deficit (n=57) syndrome. A factor analysis of test variables revealed three factors: executive functioning; simple verbal memory; and semantic verbal memory. Results indicated that the deficit group performed significantly worse on the executive functioning factor, but not on either of the verbal memory factors. These findings support the hypothesis that deficit syndrome schizophrenia represents a specific cognitive impairment in executive processing and not necessarily graver global cognitive impairment.

Adult↗

PubMed2001

Transactivation of the IGFBP-2 promoter in human tumor cell lines.

Many cancers produce high amounts of the insulin-like growth factor binding protein (IGFBP)-2, which can influence the tumorigenicity and growth of tumor cells. In order to study the possible cause of elevated expression of IGFBP-2 in tumors, we investigated the transcriptional regulation by IGF of a 633-bp fragment of the human IGFBP-2 promoter in a transiently transfected choriocarcinoma (JAR) and a leukemic T-cell line (Molt-4) that express IGFBP-2 highly, and in a leukemic B-cell line (Raji) that expresses little IGFBP-2. Strong basal promoter activity, i.e. luciferase activity was measurable in all of the tumor cell lines. The introduction of equal amounts of normal IGF-I and IGF-II stimulated the transcription of IGFBP-2 only slightly. Synthetic IGF analogues with increased biological activity, however, caused a specific 2.0-3.3-fo1d transactivation of the promoter, as well as a 25% increase in IGFBP-2 mRNA. Synchronously, IGF analogues caused a decrease in the level of IGFBP-3 mRNA of about 45%, while the production of IGFBP-2 as measured by RIA increased in relation to IGFBP-3 by up to 15 times. Blocking with the IGF antagonist JB1 revealed partial involvement of the IGF-I receptor in the regulation of IGFBP-2 expression by locally produced IGF. We conclude, that the reduced ability of IGF analogues to form complexes with locally produced IGFBP may account for their increased biological activity in the stimulation of expression of IGFBP-2 and of cell growth. Since increased biological activity had also been demonstrated for natural pro-IGF forms often produced by tumors, pro-IGFs may be involved in the mechanism leading to elevated IGFBP-2 expression of tumors in vivo.

Humans↗

PubMed2001

Imaging of small-scale features on 433 Eros from NEAR: evidence for a complex regolith.

On 25 October 2000, the Near Earth Asteroid Rendevous (NEAR)-Shoemaker spacecraft executed a low-altitude flyover of asteroid 433 Eros, making it possible to image the surface at a resolution of about 1 meter per pixel. The images reveal an evolved surface distinguished by an abundance of ejecta blocks, a dearth of small craters, and smooth material infilling some topographic lows. The subdued appearance of craters of different diameters and the variety of blocks and different degrees of their burial suggest that ejecta from several impact events blanketed the region imaged at closest approach and led to the building up of a substantial and complex regolith consisting of fine materials and abundant meter-sized blocks.

Journal Article↗

PubMed2001

Isolation of hyperactive mutants of the MAPK p38/Hog1 that are independent of MAPK kinase activation.

Mitogen-activated protein kinases (MAPKs) play pivotal roles in growth, development, differentiation, and apoptosis. The exact role of a given MAPK in these processes is not fully understood. This question could be addressed using active forms of these enzymes that are independent of external stimulation and upstream regulation. Yet, such molecules are not available. MAPK activation requires dual phosphorylation, on neighboring Tyr and Thr residues, catalyzed by MAPK kinases (MAPKKs). It is not known how to force MAPK activation independent of MAPKK phosphorylation. Here we describe a series of nine hyperactive (catalytically and biologically), MAPKK-independent variants of the MAPK Hog1. Each of the active molecules contains just a single point mutation. Six mutations are in the conserved L16 domain of the protein. The active Hog1 mutants were obtained through a novel genetic screen that could be applied for isolation of active MAPKs of other families. Equivalent mutations, introduced to the human p38alpha, rendered the enzyme active even when produced in Escherichia coli, showing that the mutations increased the intrinsic catalytic activity of p38. It implies that the activating mutations could be directly used for production of active forms of MAPKs from yeasts to humans and could open the way to revealing their biological functions.

Amino Acid Sequence↗

PubMed2001

Runx2: a novel oncogenic effector revealed by in vivo complementation and retroviral tagging.

The Runx2 (Cbfa1, Pebp2alphaA, Aml3) gene was previously identified as a frequent target for transcriptional activation by proviral insertion in T-cell lymphomas of CD2-MYC transgenic mice. We have recently shown that over-expression of the full-length, most highly expressed Runx2 isoform in the thymus perturbs T-cell development, leads to development of spontaneous lymphomas at low frequency and is strongly synergistic with Myc. To gain further insight into the relationship of Runx2 to other lymphomagenic pathways, we tested the effect of combining the CD2-Runx2 transgene either with a Pim1 transgene (E(mu)-Pim1) or with the p53 null genotype, as each of these displays independent synergy with Myc. In both cases we observed synergistic tumour development. However, Runx2 appeared to have a dominant effect on the tumour phenotype in each case, with most tumours conforming to the CD3(+), CD8(+), CD4(+/-) phenotype seen in CD2-Runx2 mice. Neonatal infection of CD2-Runx2 mice with Moloney murine leukaemia virus (Moloney MLV) also led to a dramatic acceleration of tumour onset. Analysis of known Moloney MLV target genes in these lymphomas showed a high frequency of rearrangement at c-Myc or N-Myc (82%), and a significant number at Pim1 or Pim2 (23%), and at Pal1/Gfi1 (18%). These results indicate that Runx2 makes a distinct contribution to T-cell lymphoma development which does not coincide with any of the oncogene complementation groups previously identified by retroviral tagging.

ATP-Binding Cassette Transporters↗

PubMed2001

Neurocognitive enhancement therapy with work therapy: effects on neuropsychological test performance.

BACKGROUND: Cognitive deficits are a major determinant of social and occupational dysfunction in schizophrenia. In this study, we determined whether neurocognitive enhancement therapy (NET) in combination with work therapy (WT) would improve performance on neuropsychological tests related to but different from the training tasks. METHODS: Sixty-five patients with schizophrenia or schizoaffective disorder were randomly assigned to NET plus WT or WT alone. Neurocognitive enhancement therapy included computer-based training on attention, memory, and executive function tasks; an information processing group; and feedback on cognitive performance in the workplace. Work therapy included paid work activity in job placements at the medical center (eg, mail room, grounds, library) with accompanying supports. Neuropsychological testing was performed at intake and 5 months later. RESULTS: Prior to enrollment, both groups did poorly on neuropsychological testing. Patients receiving NET + WT showed greater improvements on pretest-posttest variables of executive function, working memory, and affect recognition. As many as 60% in the NET + WT group improved on some measures and were 4 to 5 times more likely to show large effect-size improvements. The number of patients with normal working memory performance increased significantly with NET + WT, from 45% to 77%, compared with a decrease from 56% to 45% for those receiving WT. CONCLUSIONS: Computer training for cognitive dysfunction in patients with schizophrenia can have benefits that generalize to independent outcome measures. Efficacy may result from a synergy between NET, which encourages mental activity, and WT, which allows a natural context for mental activity to be exercised, generalized, and reinforced.

Adult↗

PubMed2001

Cytokines and malaria parasitemia.

The balance between pro- and antiinflammatory cytokines may be important in malaria presentation and outcome. Malaria tends to be more severe in children than in adults, presumably because partial immunity develops with age. However, the full nature of, and age-related differences in, anti-malarial immunity are unknown. We compared: (1) serum and cell-specific cytokines of patients with acute malaria to those of patients with other acute illnesses and to those of healthy adults and (2) the cytokine responses of parasitemic children and parasitemic adults. Flow cytometry was done on the peripheral blood mononuclear cells of 148 hospitalized children, 161 febrile hospitalized adults, and 20 healthy adults in Malawi, Africa, a malaria-endemic country. Serum cytokines were also assessed for 80 of these patients. Thirty-eight participants were parasitemic with Plasmodium falciparum. Serum interleukin (IL)-10 (an antiinflammatory, immunoregulatory, and type 2 cytokine) levels were higher in malaria patients than in other patients (medians 502 pg/mL vs 16 pg/mL, P = 0.002), and the percentages of various lymphocyte populations making IL-6 (a proinflammatory, type 2 cytokine regulating iron distribution) were lower in malaria patients than in other patients (e.g., for spontaneous production by children's CD8(+) T cells: medians 1.4% vs 33.1%, P = 0.004). For adult patients, the percentages of lymphocytes spontaneously making IL-4 (a type 2 cytokine) were significantly lower in those with malaria than in those without malaria (medians 0.9% vs 2.1%, P = 0.005). The percentages of monocytes spontaneously making IL-8 (a chemotactic, proinflammatory chemokine) were higher in parasitemic children than in parasitemic adults (medians 5.8% vs 1.7%, P = 0.003). A number of cellular proinflammatory, type 1 parameters were significantly higher in all children (with or without malaria) than in all adults; these included the percentages of various lymphocyte populations making IL-6, both IL-6 and interferon-gamma, or IL-8. These data support the importance of IL-10 in malaria parasitemia. Given the lack of an IL-4 (type 2) response, IL-10's primary role may be immunoregulatory rather than type 2 in nature. In this study, the immune response to malaria was more proinflammatory in children than in adults. This difference, if corroborated by other studies, could be related to malaria's greater severity in children.

Adolescent↗

PubMed2001

Seasonal variation in the etiology of bloodstream infections in a febrile inpatient population in a developing country.

OBJECTIVES: Published data suggest that Streptococcus pneumoniae, non-typhi Salmonella species, and Mycobacterium tuberculosis are the predominant causes of bloodstream infection (BSI) in hospitalized populations in sub-Saharan Africa. This study was conducted during the wet season to ascertain the etiology and prevalence of BSI among febrile inpatients in a hospital where the dry season BSI profile in a similar study population had already been documented. METHODS: In the period from March to May 1998, consecutive febrile (> or = 37.5 degrees C) adult (> or = 14 y) patients presenting to a Malawi hospital were enrolled after providing informed consent. Following clinical evaluation, blood was drawn for culture (bacteria, mycobacteria, and fungi), human immunodeficiency virus (HIV) testing, and malaria smears. RESULTS: Of 238 enrolled patients, 173 (73%) were HIV-positive and 67 (28%) had BSI. The predominant wet season BSI pathogens were non-typhi Salmonella species (41%), M. tuberculosis (19%), and Cryptococcus neoformans (9%) (cf. the predominant dry season pathogen was S. pneumoniae). Mycobacteremia was more likely in HIV-positive than in HIV-negative patients (13/173 vs. 0/65; P < 0.05). A logistic regression model yielded clinical predictors of BSI that included chronic fever, oral candidiasis, or acute diarrhea. CONCLUSION: Pathogens causing BSI in febrile inpatients in a Malawi teaching hospital vary by season. Season- and country-specific studies, such as this one, provide data that may facilitate empirical therapy of febrile illnesses whose etiologies vary by season.

Adolescent↗

PubMed2001

The effects of iron deficiency on lymphocyte cytokine production and activation: preservation of hepatic iron but not at all cost.

Worldwide, over 40% of children have iron deficiency anaemia, frequently associated with infections. Certain cytokines are involved in both immune activation/response to infection and iron transport/metabolism. We therefore assessed the relations among iron deficiency, cytokine production and lymphocyte activation markers in 142 hospitalized Malawian children. We examined peripheral blood lymphocyte antigens/cytokine production using four- colour flow cytometry and serum transferrin receptor (TfR) levels, an inverse measure of iron status unaffected by acute illness or infection, with an enzyme-linked immunosorbent assay. Wilcoxon rank sum tests and logistic regression analyses (LRA) were performed. Iron deficiency (TfR > or = 10 microg/ml) versus TfR < 10 microg/ml, was associated with higher percentages of lymphocytes producing: (a) induced or spontaneous IL-6 (medians: induced, 15.9% for iron-deficient children versus 8.8% for iron-replete children, P = 0.002; spontaneous, 24.4% versus 13.0%, P < 0.001) and (b) induced IFN-gamma (medians:18.4% versus 12.4%, P = 0.006). The percentages of CD8(+) T cells spontaneously producing IL-6 and of all lymphocytes producing induced TNF-alpha and IFN-gamma in the same cell had the strongest relationships to iron deficiency (b = + 0.0211, P = 0.005 and b = + 0.1158, P = 0.012, respectively, LRA) and were also positively related to the co-expression of the T cell activation markers HLA DR and CD38. Severe iron deficiency (TfR > or = 30 microg/ml) was associated with the percentage of lymphocytes producing induced IL-4 (medians: 0.5% versus 1.6%, P < 0.010). The cytokine patterns associated with iron deficiency in our study would preserve iron stores but also preferentially retain the activation capabilities of T cells, albeit not necessarily other immune cells, until a critical level of iron depletion is reached.

Adolescent↗