Clonal dysregulation of the antibody response to tetanus-toxoid after bone marrow transplantation

After bone marrow transplantation (BMT), a prolonged dysregulation of humoral immunity can be observed. In the present study, we investigated whether this is reflected in an abnormal production of specific antibodies (Ab) to the T-cell-dependent recall antigen tetanus-toxoid (TT). The study group consisted of children receiving transplants of an unmodified allogeneic graft and of adults receiving either a T-cell- depleted allogeneic or an unmodified autologous BM graft. Findings were compared with those in healthy controls. In pediatric graft recipients, who were routinely revaccinated early after BMT, the Ab response was quantitatively superior to that in adult graft recipients who did not receive early revaccination. In the majority of graft recipients, the time period after vaccination required to reach the peak level of antibodies was prolonged and the number of responding TT-specific B- cell clones was markedly decreased in comparison with controls. In controls, a low frequency of dominant B-cell clones may produce low quantities of homogeneous Ab components (H-Ab) against a heterogeneous background. However, in BM graft recipients, "overshooting" of Ab production by separate B-cell clones was observed, resulting in the development of H-Ab at a relatively high concentration. These abnormalities were present up to 10 years after BMT, irrespective of either the age of the recipient, the modulation of the graft, or the vaccination schedule used. It is hypothesized that the dysregulated Ab production is the consequence of activation of a restricted number of resting memory B cells, present in germinal centers, repopulating gradually after BMT. Our data show that routine revaccination early after BMT improves the humoral immune response. However, because of a clonally dysregulated Ab production, long-lasting qualitative defects may be present even after normalization of Ab titers.     

Regulation of stimulated integrin surface expression in human neutrophils by tyrosine phosphorylation

The control of the adhesive properties of human neutrophils is an essential element of their defense function. One level at which this control is exerted involves the upregulation of the surface expression of beta 2-integrins. In this study, we have examined the potential involvement of tyrosine phosphorylation in the latter process. Two inhibitors of tyrosine kinases with differing modes of action, erbstatin and herbimycin A, were found to inhibit the expression of CD11b and CD18 stimulated by chemotactic factors (fMet-Leu-Phe or leukotriene B4) or growth factors (tumor necrosis factor alpha). This inhibition was not shared by an inactive analog of erbstatin or by the protein kinase C inhibitor Ro 31-8330. Erbstatin also inhibited the unveiling of activation-specific neoepitopes detected by antibody CBRM1/5. Pretreatment of neutrophils (but not of endothelial cells) with erbstatin inhibited the stimulation of neutrophils' adherence to endothelial cells induced by fMet-Leu-Phe. Augmentation of tyrosine phosphorylation by inhibiting tyrosine phosphatases using hydroperoxyvanadate led to an increased surface expression of CD11b and CD18 and enhanced the adhesion of neutrophils to endothelial cells. Finally, the leumedin NPC 15669, which had previously been shown to inhibit stimulated CD11b expression and neutrophil adherence to endothelial cells and to exhibit anti-inflammatory properties in various in vivo models of inflammation, inhibited the stimulation of tyrosine, phosphorylation induced by fMet-Leu-Phe. Taken together, these data establish a strong correlation between tyrosine phosphorylation and integrin upregulation in stimulated human neutrophils.     

Assessing the delivery of neutrophils to tissues in neutropenia

Studies of neutrophil kinetics in neutropenic individuals, as well as clinical observations of variability in the occurrence of infection among patients with neutropenia, have suggested that blood neutrophil counts may not uniformly reflect the effective delivery of neutrophils to extravascular tissues where the cells perform their principal host defense functions. To evaluate this possibility we developed a sensitive, reproducible method of measuring the extravascular delivery of neutrophils to a normal mucosal site of neutrophil turnover. This method is based upon the quantification of neutrophils recoverable from saline mouth wash specimens. Twenty-five mL specimens, obtained in a controlled manner from neutropenic patients and normal subjects, were centrifuged and the sediments resuspended in 1.0 mL Hank's buffer with 2 micrograms acridine orange, incubated at 37 degrees C for 15 minutes, and then examined in a hemocytometer chamber by fluorescence microscopy. Neutrophils could be clearly distinguished by their characteristic fluorescence and were counted. With this method as few as 1,500 neutrophils were detected reliably in mouth wash specimens. Mucosal neutrophil counts varied less than 10% with repeated sampling of individual subjects over 5-day periods and were consistently greater than 1.3 X 10(5)/specimen in non-neutropenic individuals. Although profound neutropenia was generally reflected by lower than normal oral mucosal neutrophil counts, these counts were significantly higher in individuals with chronic severe neutropenia (blood neutrophils less than 300/mm3) than in patients with acute neutropenia of comparable severity that had developed following chemotherapy. Also, in individuals recovering from profound neutropenia, neutrophils usually reappeared earlier in mouth wash specimens than in blood, and oral mucosal neutrophil counts attained recovery levels more rapidly than did blood counts. This phenomenon was particularly evident in an individual with cyclic neutropenia. Moreover, mucosal neutrophils could occasionally be detected in profoundly neutropenic patients when neutrophils were not present in blood samples. These findings indicate that mucosal neutrophil counts in individuals with neutropenia provide information about the delivery of neutrophils to tissues that may not be apparent from blood neutrophil counts alone.     

A Prospective Study of Growth and Biomarkers of Exposure to Aflatoxin and Fumonisin during Early Childhood in Tanzania

Background: Aflatoxin and fumonisin are toxic food contaminants. Knowledge about effects of their exposure and coexposure on child growth is inadequate.Objective: We investigated the association between child growth and aflatoxin and fumonisin exposure in Tanzania.Methods: A total of 166 children were recruited at 6–14 months of age and studied at recruitment, and at the 6th and 12th month following recruitment. Blood and urine samples were collected and analyzed for plasma aflatoxin–albumin adducts (AF-alb) using ELISA, and urinary fumonisin B₁ (UFB1) using liquid chromatography–mass spectrometry, respectively. Anthropometric measurements were taken, and growth index z-scores were computed.Results: AF-alb geometric mean concentrations (95% CIs) were 4.7 (3.9, 5.6), 12.9 (9.9, 16.7), and 23.5 (19.9, 27.7) pg/mg albumin at recruitment, 6 months, and 12 months from recruitment, respectively. At these respective sampling times, geometric mean UFB1 concentrations (95% CI) were 313.9 (257.4, 382.9), 167.3 (135.4, 206.7), and 569.5 (464.5, 698.2) pg/mL urine, and the prevalence of stunted children was 44%, 55%, and 56%, respectively. UFB1 concentrations at recruitment were negatively associated with length-for-age z-scores (LAZ) at 6 months (p = 0.016) and at 12 months from recruitment (p = 0.014). The mean UFB1 of the three sampling times (at recruitment and at 6 and 12 months from recruitment) in each child was negatively associated with LAZ (p < 0.001) and length velocity (p = 0.004) at 12 months from recruitment. The negative association between AF-alb and child growth did not reach statistical significance.Conclusions: Exposure to fumonisin alone or coexposure with aflatoxins may contribute to child growth impairment.Citation: Shirima CP, Kimanya ME, Routledge MN, Srey C, Kinabo JL, Humpf HU, Wild CP, Tu YK, Gong YY. 2015. A prospective study of growth and biomarkers of exposure to aflatoxin and fumonisin during early childhood in Tanzania. Environ Health Perspect 123:173–178; http://dx.doi.org/10.1289/ehp.1408097     

Patient nonadherence to medication in inflammatory bowel disease

OBJECTIVE: The aim of this study was to identify determinants of nonadherence to medication in outpatients with established inflammatory bowel disease (IBD). METHODS: Ten gastroenterologists and 153 of their IBD patients participated in this prospective study. Demographic, clinical, and psychosocial characteristics, as well as patient-physician discordance, were assessed at an office visit. Nonadherence to medication was assessed 2 wk later. Separate generalized estimating equations were used to identify determinants of nonadherence. RESULTS: Physicians averaged 47.9 yr in age (range 30.1-57.5 yr), and 90% were male. Patients averaged 37.0 yr (SD = 15.1), and 87 (56.9%) were female. In all, 63 patients (41.2%) were nonadherent to medication; of these, 51 (81.0%) indicated unintentional nonadherence, 23 (36.5%) intentional nonadherence, and 11 (17.5%) both. Overall nonadherence was predicted by disease activity (OR = 0.55, p = 0.0022), new patient status (OR = 2.14, p = 0.0394), disease duration (OR = 0.50, p = 0.0001), and scheduling a follow-up appointment (OR = 0.30, p = 0.0059), whereas higher discordance on well-being was predictive only in psychologically nondistressed patients (p = 0.0026 for interaction). Unintentional nonadherence was predicted by age (OR = 0.97, p = 0.0072), new patient status (OR = 2.80, p = 0239), and higher discordance on well-being in psychologically nondistressed patients (p = 0.0504). Intentional nonadherence was predicted by disease duration (OR = 0.55, p = 0032), scheduling a follow-up appointment (OR = 0.12, p = 0.0001), certainty that medication would be helpful (OR = 0.99, p = 0.0409), and total patient-physician discordance (OR = 1.59, p =.0120). CONCLUSIONS: These findings suggest that the therapeutic relationship, as well as individual clinical and psychosocial characteristics, influence adherence to medication.     

Dietary Lipids Alter the Effect of Steroids on the Transport of Fructose Following Intestinal Resection in Rats

BACKGROUND: Glucocorticosteroids alter intestinal morphology and transport. We tested the hypothesis that the desired intestinal adaptive response following intestinal resection may be enhanced further by the locally active steroid budesonide, and by feeding a saturated as compared with a polyunsaturated fatty acid diet. METHODS: An in-vitro uptake method was used to assess intestinal fructose uptake by rats of semisynthetic diets enriched in saturated or polyunsaturated fatty acids, and injected with budesonide or control solution. RESULTS: Budesonide increased ileal fructose uptake in chow and PUFA-fed animals, but reduced jejunal fructose uptake in rats fed SFA. GLUT5 and GLUT2 protein and mRNA did not correlate with changes in fructose uptake. Steroids reduced jejunal proglucagon expression in animals fed chow. Animals fed SFA and given budesonide had a reduction in jejunal ODC mRNA compared with those fed PUFA or chow. CONCLUSIONS: (1) budesonide increases ileal fructose uptake following intestinal resection, and this beneficial effect is prevented by feeding SFA rather than PUFA; (2) fructose uptake does not correlate with GLUT5 and GLUT2 protein and mRNA; (3) ODC and proglucagon may be involved in this adaptive response.     

Evaluation of the effects of catheter sampling for the study of platelet behavior in the pulmonary and coronary circulation

To study the effects of sampling through cardiac catheters on indices of platelet function, we measured the levels of platelet factor 4 (PF₄), beta thromboglobulin (BTG), and platelet aggregate ratio (PAR) in 10 patients with atrioventricular accessory pathway (AVNAP), six patients with primary pulmonary hypertension (PPH), and six patients with critical narrowing of the left anterior descending artery (LAD). In AVNAP and LAD patients samples were drawn simultaneously from a peripheral vein, coronary sinus, and brachial artery; in AVNAP patients samples were also obtained from the axillary vein before the coronary sinus was entered. In PPH patients samples were drawn from pulmonary artery, aorta, and a peripheral vein; in these patients the effects of an intravenous infusion of prostacyclin (PGl₂) (2 to 8 ng/kg/min) on PF₄, BTG, and PAR were also studied at all sampling sites. In all patients arterial, coronary sinus, pulmonary arterial, and axillary venous levels of PF₄, BTG, and PAR significantly exceeded those measured in the peripheral vein. PGl₂ infusion resulted in a significant decrease of PF₄ at all sampling sites, while no consistent BTG changes were observed and PAR levels did not decrease in the peripheral vein. Although a considerable interpatient variability in PF₄ levels was observed, a significant (r = 0.91) correlation was found in patients with AVNAP between simultaneous coronary sinus and arterial PF₄ levels. The value of PF₄ coronary sinus-arterial difference in LAD patients was consistently higher than that calculated in AVNAP patients (54.5 ± 28.9 vs 4.2 ± 3.8 ng/ml). In conclusion: (1) a considerable and variable degree of platelet activation occurs with catheter sampling, preventing the measurement of absolute levels of platelet metabolites; (2) among the indices examined PF₄ appears the most sensitive for detecting changes in platelet activity; and (3) the measurement of coronary sinus-arterial PF₄ differences may provide information on directional changes in transcardiac platelet behavior.     

Partial loss of function mutations in DnaK, the Escherichia coli homologue of the 70-kDa heat shock proteins, affect highly conserved amino acids implicated in ATP binding and hydrolysis.

A set of 37 mutations in DnaK, the Escherichia coli homologue of the 70-kDa heat shock proteins, was isolated using a selection for high constitutive expression of heat shock proteins. Of these, 11 mutants were able to carry out some but not all functions of DnaK. These partial function mutants were divided into two classes. Class I mutants are recessive and permit replication of bacteriophage lambda and growth of cells up to 40 degrees C. Class II mutants are dominant, do not permit growth of lambda, and are temperature-sensitive for growth above 34 degrees C. Mutations in both classes alter amino acids that are highly conserved in the 70-kDa heat shock protein family. The dominant negative mutations provide strong genetic evidence that at least one form of DnaK is multimeric. Moreover, every dominant negative mutation occurs at an amino acid that has been hypothesized to be intimately involved in the process of ATP binding and hydrolysis. Our findings provide strong support for the hypothesis that such mutations are excellent tools for identifying amino acids that play critical roles in protein function.     

Psychological Adaptation to Serious Illness: A Qualitative Study of Culturally Diverse Patients With Advanced Chronic Kidney Disease

ContextPsychological distress is associated with adverse health outcomes in serious illness and magnified among patients of low socioeconomic status. Aspects of one's culture, such as religion and spirituality, can influence these patients' coping response to distress. Advanced chronic kidney disease (CKD) is a serious illness that disproportionately affects patients of low socioeconomic status, but a theory-based understanding of this group's lived experience of CKD is lacking.ObjectivesWe explored the cognitions, emotions, and coping behaviors of patients with CKD with emphasis on those of low socioeconomic status. We further inquired into any influences of religion or spirituality.MethodsWe interviewed 50 English-speaking or Spanish-speaking adults with advanced CKD from three medical centers in Nashville, Tennessee. Analyses occurred with isolation of themes; development of a coding system; and creation of a conceptual framework using an inductive-deductive approach.ResultsMedian age was 65 years; median annual income was $17,500 per year; and 48% of participants had not progressed beyond high school. Key beliefs (awareness of mortality and lack of control) influenced patients' emotions (existential distress in the form of death anxiety, prognostic uncertainty, and hopelessness) and coping behaviors (acceptance, avoidance, emotion regulation via spirituality, and seeking social support via a religious community).ConclusionIndividuals with advanced CKD and low socioeconomic status lack control over disease progression, experience death anxiety and existential distress, and emphasize spirituality to cope. Our study identifies novel components for a psychotherapeutic intervention for patients with advanced CKD at high risk for adverse health outcomes.