Altered airway responsiveness in CD38-deficient mice

Cyclic ADP-ribose (cADPR) mobilizes calcium from intracellular stores and contributes to agonist-induced intracellular calcium elevation in airway smooth muscle (ASM). In this study we determined the functional role of CD38/cADPR signaling in the regulation of airway tone using CD38 deficient (cd38(-/-)) mice. The responsiveness to different doses of methacholine, as determined by changes in lung resistance and dynamic compliance, was significantly (P < or = 0.05) lower in cd38(-/-) mice compared with wild-type controls. To determine the mechanism responsible for the reduced responsiveness, we measured the intracellular calcium responses to contractile agonists in ASM cells. In ASM cells isolated from cd38(-/-) mice, the intracellular calcium responses to acetylcholine and endothelin-1 were significantly lower than in controls. Pretreatment of ASM cells with a cADPR antagonist resulted in attenuated intracellular calcium responses to endothelin-1 in cells isolated from wild-type mice, but not in those isolated from the cd38(-/-) mice. Very low cADPR levels and no detectable ADP-ribosyl cyclase activity were observed in lung tissue from cd38(-/-) mice, suggesting that CD38 is a critical source for cADPR synthesis. The results of the present study demonstrate that CD38/cADPR contributes to airway smooth muscle tone and responsiveness through its effects on agonist-induced elevation of intracellular calcium in ASM cells.     

Transient expression of keratin 19 is induced in originally negative interfollicular epidermal cells by adhesion of suspended cells

Keratin 19 and nuclear reactivity to an endogenous lectin, galectin-1, represent a potential marker of epidermal stem cells. We detected expression of keratin 19 and nuclear binding sites for galectin-1 in adult cells migrating from the hair follicle, where cells expressing keratin 19 are located in the bulge region. The results were compared with the expression of both markers in cells adhering from suspension prepared from the interfollicular epidermis without keratin-19-positive cells and with nuclear binding sites for galectin-1. The results were compared with data from basal cell carcinomas. All cells were analyzed concerning size, as it is known that cell diameter influences the clonogenic potential of keratinocytes. The major result of this study is the observation of transient expression of keratin 19 and nuclear galectin-1 binding sites in originally negative interfollicular epidermal cells induced by adhesion. These cells were very small in size, similar to basal cells of the interfollicular epidermis or the bulge region of the hair follicle. The influence of the suspension regimen on beta1-integrin expression, cell diameter and growth was also monitored. A population of cells highly positive for beta1 integrin of the same diameter as keratin-19-positive cells insensitive to induction of terminal differentiation by lack of anchorage was characterized. Cells of the same size were also observed in the keratin-19-positive cells of basal cell carcinomas. In conclusion, the expression of poor levels of differentiation induced by cell adhesion is transient. Also, keratin 19 expression should not be exclusively regarded as a marker of stem cell activity.     

Erratum: Sodium channel gene (SCN5A) mutations in 44 index patients with brugada syndrome: Different incidences in familial and sporadic disease

In supplementation of previously published cardiac sodium channel (SCN5A) gene mutations that were cited in the text, in Table 2 and in Figure 2 we here apply an updated gene mutation nomenclature (Human Genome Variation Society, 2005) to facilitate mutation annotation comparison (SCN5A cDNA reference: NM_198056.1 or GI: 37622906; amino acid reference sequence: SWISS‐PROT entry Q14524, long splice variant, 2,016 amino acids): Mutation: c.2602delC Amino acid change: p.Glu868X Mutation: c.2581_2582delTT Amino acid change: p.Phe861Trp fsX90 Mutation: c.4477_4479delAAG Amino acid change: p.Lys1493del Mutation: c.5425C>A Amino acid change: p.Ser1812X     

Prostate implant evaluation using tumour control probability--the effect of input parameters

In this paper, we examine the effect of treatment parameters in a model used to evaluate permanent prostate implants. The model considers the prostate to be composed of 12 sub-sections, each sub-section is assigned a cell density based on the probability of finding cancer foci in that sub-section. Wasted dose as a result of the dose rate from the implant falling below a level adequate to counteract repopulation was found to vary by 2-16% over the range of radiosensitivity and repopulation rates considered. Within the model, applied to five dose distributions, the uncertainty in the tumour control probability (TCP) values calculated for each sub-section as a result of differences in the model parameters, was found to be less than 12% in most cases for the good quality implants. The difference in TCP values was much larger for the poor quality implant. Substituting a heterogeneous distribution of alpha for a single mean value resulted in generally lower TCP values though introducing a cutoff value with a Gaussian distribution had a profound effect on the calculated values. Despite uncertainties in the parameters, the model was able to identify sub-sections at risk of local recurrence but as a result of these uncertainties, the TCP values can only be considered in the relative rather than absolute sense.     

Intrathyroidal accumulation of T cell phenotypes in autoimmune thyroid disease.

In this study we have correlated peripheral T cell subset phenotypes with intrathyroidal lymphocyte accumulation in patients with autoimmune thyroid disease (Graves' and Hashimoto's disease). Our study utilized euthyroid family members for one of our control groups (n = 48) thus significantly limiting familial, but not disease-specific, influences on these T cell phenotypes. Our principal new observations were found only in patients with Graves' disease. As previously reported, there was a decrease in CD8+ (suppressor/cytotoxic) T cells in the peripheral blood of patients with untreated hyperthyroid Graves' disease (n = 27) (mean +/- SEM, 19 +/- 1.1% in patients compared with 25 +/- 1.2% in controls, p = 0.03), a finding not observed in treated, euthyroid Graves' disease patients or their relatives. However, the relative number of CD8+ T cells, assessed by CD4:CD8 ratios, was increased in the intrathyroidal T cell populations (n = 10), when compared to normal and patient peripheral blood. There were no consistent changes in total CD4+ (helper) T cells in the peripheral blood of patients with treated and untreated Graves' disease but a reduction in CD4+2H4+ (suppressor-inducer) T cells was seen in patients undergoing surgery for Graves' disease (13 +/- 6.9% compared with 39 +/- 3.4%). Again, however, this T cell subset was increased within the target organ of the same patients (41 +/- 5.9%). These data point to either a selective accumulation, or a specific "homing", of certain T cell subsets within the thyroid gland of patients with Graves' disease where T cell differentiation may be strongly influenced by antithyroid drug treatment and the local immune environment.     

Increased chloride permeability of amphibian epithelia treated with aldosterone

The transepithelial flux of chloride was increased by aldosterone treatment of amphibian skin and bladder and this was reflected by increased shunt conductance. The hormonal effect depended on the presence of chloride on the epithelial side of the preparation. These changes in tissue conductance and chloride permeability appear to be a direct effect of aldosterone as they did not occur when sodium transport was stimulated with vasopressin or hypotonicity.Chloride efflux was reduced in magnitude by indacrinone and DIDS, as well as after removal of chloride from the solution on the epithelial side of the preparations. These results suggest that, rather than merely diffusing along (a) paracellular pathway(s), chloride flows through (a) cellular structure(s), notably mitochondria-rich cells. These cells can therefore be considered as targets for aldosterone.Presented in part before the Belgian Physiological Society (Beauwens et al. 1985)     

Monoclonal antibody to human granulocytes: cellular specificity and functional studies

Antigenic specificity and functional studies of G2, a monoclonal antibody to human granulocytes, prepared by fusing spleen cells from immunized Balb/c mice to the nonimmunoglobulin (Ig) secretor line SP2/0, are described. The antibody was reactive with the HL60 and K562 cell lines and with human peripheral blood granulocytes; and unreactive toward human lymphocytes, erythrocytes, a variety of T and B cell lines, as well as toward leukemic cells obtained from patients with acute lymphocytic leukemia (ALL), chronic lymphocytic leukemia (CLL), and acute myelocytic leukemia (AML). The G2 monoclonal antibody identified cell surface antigens on cells from cases of acute myelomonocytic leukemia (AMMoL) and on cells from 2 of 12 cases of acute undifferentiated leukemia (AUL). G2 was capable of inhibiting oxygen consumption by human polymorphonuclear leukocytes (PMNL) stimulated with aggregated human immunoglobulin (IgG), opsonized zymosan, f-met-leu-phe (FMLP), and the calcium ionophore A23187. Inhibition of the PMNL response to phorbol myristate acetate (PMA) and digitonin was dependent upon the dose of the stimulant. G2 should facilitate elucidation of the mechanisms of granulocyte membrane perturbation and subsequent activation of various functions via a selective interaction with key cell surface antigens.     

Radiometric detection of carbohydrate catabolism by pathogenic Neisseria.

A liquid scintillation procedure for the catabolism of D-[1-14C]glucose and [U-14C]maltose by pathogenic Neisseria was tested. Definitive results were obtained within a 30-min incubation period.     

Extracellular cations and the movement of choline across the erythrocyte membrane

1. The ability of human erythrocytes to accumulate choline is abolished when external Na is replaced by Cs, Rb, K or Li but is increased when the external cation is Mg or Ca.2. The unidirectional influx of choline is reduced when external Na is replaced by other monovalent cations but is not changed when Na is replaced by Mg or Ca.3. The unidirectional efflux of choline into a choline-free medium is increased when external Na is replaced by other monovalent cations and markedly reduced when Na is replaced by Mg or Ca. When the external medium contains 1 mM choline, changing the external cation has virtually no effect on the rate of choline efflux.4. When the extracellular concentrations of K and Na are similar to that found in the intracellular water, choline appears to become passively distributed across the cell membrane; when the extracellular K is then replaced by Cs a net efflux of choline against a concentration gradient results.5. It is concluded that the choline carrier may be described as a cation carrier with a high affinity for choline and affinities for Cs > Rb > K > Li > Na and that these monovalent cations can cross the membrane on the choline transport system.