Lectin-induced increase in clonogenic growth of haematopoietic progenitor cells

Abstract: The galactoside-specific plant lectin, Viscum album agglutinin (VAA-I) increases cellular parameters of natural host defence. It also binds to a variety of haematopoietic cells, including progenitors. We investigated whether VAA-I has a stimulatory effect on haematopoietic progenitor cells. Peripheral blood progenitor cells from 7 healthy volunteers were cultured in a colony assay with VAA-I plus erythropoietin (EPO) and stem cell factor (SCF). At 50 pg/ml VAA-I induced a significant increase in the cytokine-dependent clonogenic growth (52% in median, p<0.05). In another set of experiments purified CD34+ cells were isolated from the bone marrow aspirate of 4 patients with non-metastatic breast cancer using fluorescence-activated cell sorting. Binding to CD34+ cells was demonstrated by using directly fluorescence-conjugated VAA-I. Co-incubation with d -galactose significantly abrogated this effect. CD34+ cells were cultured in the presence of EPO, SCF, interleukin-3, granulocyte/monocyte colony-stimulating factor and granulocyte colony-stimulating factor. VAA-I alone had no measurable effect on the clonogenic growth of the isolated cells. However, at concentrations of 100 and 250 pg/ml VAA-I increased the cytokine-dependent proliferation and differentiation of CD34+ cells by a median of 75 and 85%, respectively. The results show that VAA-I binds to haematopoietic progenitor cells and has a co-stimulatory effect on their proliferation.     

Analgesic nephropathy in Hungary: the HANS study.

BACKGROUND: The diagnosis of analgesic nephropathy has improved significantly with modern imaging techniques. We reviewed a large portion of the Hungarian dialysis population to obtain additional insight into the problem. METHODS: Twenty-two participating dialysis units enrolled 1400 patients on renal replacement therapy between 1 January 1995 and 1 January 1998. Patients with no known aetiology (n = 284) were interviewed and studied with renal imaging. We assessed the presence of decreased renal mass combined with either bumpy contours, papillary calcification, or both. The subjects studied were interrogated extensively. RESULTS: Our survey suggested analgesic nephropathy in 47 of 1400 patients (3.3%), 3-fold higher than the EDTA database estimate for Hungary. The analgesics most commonly abused were phenacetin-containing mixtures. The driving symptoms were mainly headache and joint pain. Cardiovascular complications were more common than in the rest of the dialysis population, independent of smoking and lipid values (P<0.01). CONCLUSIONS: Phenacetin should be banned. Our study results support the need for longitudinal cohort and case-control studies in Hungary.     

Leukemoid reaction: a diagnostic clue in metastatic carcinoma mimicking classic Hodgkin lymphoma

We report on 2 patients who were initially suspected to have classic Hodgkin lymphoma because of lymphadenopathy and the presence of Reed-Sternberg-like cells. Both patients had an associated leukemoid reaction (using a threshold leukocyte count of 50 000/microL) and were eventually diagnosed with metastatic carcinoma. Disseminated carcinoma can mimic Hodgkin lymphoma clinically, radiologically, and histologically. Reed-Sternberg-like cells may be found in carcinomas, and they represent a particularly challenging diagnostic pitfall for the unwary. When these cells lead to a suspicion of Hodgkin lymphoma, the presence of a leukemoid reaction should prompt the pathologist to question the diagnosis. Misdiagnosis can be avoided by the use of cytokeratin whenever a leukemoid reaction is present in a suspected case of Hodgkin lymphoma.     

HLA-DR and H-2E transgenes differentially mediate TCR-specific positive selection

The use of HLA transgenic mice in models of immunity and diseaseassumes that human MHC molecules are able to contribute towardthe positive selection of the mouse TCR repertoire. As an initialstep towards analysis of this we have compared the relativeability of DR/Eß or E/Eß complexes to induceT cell receptor (TCR) positive selection in H-2Ea and HLA-DRAtransgenic mice lacking endogenous E. The results show that,like E/Eß, the hybrid DR/ß complexes arecapable of mediating positive selection of V_ß2⁺;,V_ß6⁺, and V_ß10⁺ cells. However, differenceswere found between the effects of the two transgenes. Thus,while V_ß6⁺ cells were efficiently selected in bothH-2Ea and DRA transgenic mice, positive selection of V_ß10⁺cells was less apparent in the DRA transgenic mice. Variationbetween Ea and DRA transgenic mice is consistent with the notionthat this process is dependent on differential binding of endogenouspeptides to the E/Eß and DR/Eß complexes.Furthermore, contrary to expectations, in neither set of micewas positive selection limited solely to the CD4⁺ subset. Thus,examples were found in which V_ß-specific positiveselection was confined to either the CD4⁺ or CD8⁺ subsets, andothers in which both subpopulations were concomltantly increased.In the case of V_ß2 positive selection, H-2Ea transgenicmice showed expansion of these cells in both the CD4⁺ and CD8⁺subpopulations whlle in DRA transgenic mice this occurred predominantlyin the CD8⁺ subpopulatlon.     

Telomere length analysis on cord blood cells by the flow-FISH method

Telomerase is the enzyme responsible for synthesizing telomeric repeats at the ends of chromosomes to maintain telomere length. Recent studies have suggested that telomere shortening may serve as a surrogate marker of the progression of malignant disorders and seems to be accelerated in allogeneic bone marrow transplant recipients. In this study, the results of the telomere length of nine cord blood mononuclear cell samples are presented. Telomere length was measured by the flow-FISH method, using a peptide nucleic acid probe. The proportion of cord blood cell subsets (CD19/CD34/CD3) was also evaluated. The telomere length of the internal control 1301 cell line was estimated to be 100%. The mean telomere length of cord blood cells was 18.5 +/- 3.9%, compared with the internal control. The progenitor CD34+ cells were detected as 2.6 +/- 0.7% in the lymphoid gate measured. Linear correlation analysis did not find any connection between the cell subsets (CD3+, CD34+, CD19+) and the telomere length. The findings confirm that the telomere flow-FISH method is sufficient for estimation of the telomere length. Assessment of the current procedures of collection, manipulation, and ex vivo expansion of cord blood cells in terms of their effect on telomere shortening might be important.     

Molecular Evidence for the Existence of Two Distinct Subgroups in Cucumber Mosaic Cucumovirus

Infectious full-length cDNA clones from the genomic RNAs of a subgroup II cucumber mosaic cucumovirus strain (Trk7) were obtained. Sequence analysis of the whole genome revealed strong homology (99%) to the genome of Q-CMV, the only subgroup II strain whose entire genomic nucleotide sequence had been available in the database, and an overall 75% homology to those of subgroup I strains. We provide sequence comparisons of different parts of 1a, 2a and 2b proteins of Cucumovirus species, and propose phylogenetic trees based on these protein sequences.     

Tuberculosis infection and disease in South African adolescents with perinatally acquired HIV on antiretroviral therapy: a cohort study

IntroductionThere are limited data on Tuberculosis (TB) in adolescents with perinatally acquired HIV (APHIV). We examined the incidence and determinants of TB infection and disease in the Cape Town Adolescent Antiretroviral Cohort (CTAAC).MethodsYouth between nine and fourteen years on antiretroviral therapy (ART) for more than six months in public sector care, and age‐matched HIV‐negative adolescents, were enrolled between July 2013 through March 2015 and followed six‐monthly. Data were censored on 31 October 2018. Symptom screening, chest radiograph, viral load, CD4 count, QuantiFERON (QFT) and sputum for Xpert MTB/RIF, microscopy, culture and sensitivity were performed annually. TB infection was defined by a QFT of >0.35 IU/mL. TB diagnosis was defined as confirmed (culture or Xpert MTB/RIF positive) or unconfirmed (clinical diagnosis and started on TB treatment). Analyses examined the incidence and determinants of TB infection and disease.ResultsOverall 496 HIV+ and 103 HIV‐negative participants (median age at enrolment 12 years (interquartile range, IQR 10.6 to 13.3) were followed for a median of 3.1 years (IQR 3.0 to 3.4); 50% (298/599) were male. APHIV initiated ART at median age 4.4 years (IQR 2.1 to 7.6). At enrolment, 376/496 (76%) had HIV viral load <40 copies/mL, median CD4 count was 713 cells/mm³ and 179/559 (32%) were QFT+, with no difference by HIV status (APHIV 154/468, 33%; HIV negative 25/91, 27%; p = 0.31). The cumulative QFT+ prevalence was similar (APHIV 225/492, 46%; 95%CI 41% to 50%; HIV negative 44/98, 45%; 95% CI 35% to 55%; p = 0.88). APHIV had a higher incidence of all TB disease than HIV‐negative adolescents (2.2/100PY, 95% CI 1.6 to 3.1 vs. 0.3/100PY, 95% CI 0.04 to 2.2; IRR 7.36, 95% CI 1.01 to 53.55). The rate of bacteriologically confirmed TB in APHIV was 1.3/100 PY compared to 0.3/100PY for HIV‐negative adolescents, suggesting a fourfold increased risk of developing TB disease in APHIV despite access to ART. In addition, a positive QFT at enrolment was not predictive of TB in this population.ConclusionsHigh incidence rates of TB disease occur in APHIV despite similar QFT conversion rates to HIV‐negative adolescents. Strategies to prevent TB in this vulnerable group must be strengthened.     

Cadmium uptake and depuration in different organs ofLymnaea stagnalis L. and the effect of cadmium on the natural zinc level

The uptake of cadmium (0.1 mg/L) into various organs of the pond snailLymnaea stagnalis L., the depuration of accumulated Cd, and the change in the natural Zn level under the influence of Cd treatment were investigated during a 2 month period. The snails were fed with lettuce (Latuca sativa). The concentrations of Cd were measured in the whole soft body, various organs (liver, viscera, foot), the shell and the lettuce; and zinc concentrations were measured in various organs and the lettuce. As its Cd concentration remained at 10 g/g, which was much lower than the initial value for the soft body (69.4±5.71 g/g), the shell, according to our results, is incapable of accumulating Cd. The uptake pattern of the soft body showed a correlation with the initial Cd levels depending on differences in the Cd concentration of the lettuce. At the higher initial value (69.4±5.71 g/g) the linear Cd uptake began later then it did at the lower initial value; afterwards the snail was saturated with Cd. In the case of the lower, 9.02±1.3 g/g initial concentration, a rapid linear Cd uptake occurred till the 7th day, then the intensity of the uptake decreased. Saturation occurred at 200 g/g Cd concentration, regardless of the initial value. At the lower initial tissue level, the foot and the viscera showed a linear uptake pattern, while the liver, which has the greatest accumulation ability, displayed a logarithmic uptake pattern. The initial and the final Cd concentrations in the foot, viscera, and liver of theL. stagnalis were as follows: 10.3±2.15–60.1±7.13, 5.15±1.04–156±27.2, 14.1±3.09–430±23.3 g/g respectively. The bioconcentration factors (CF) were in the 10² (foot) and 10³ (viscera, liver, soft body) orders of magnitude. Forty to 45% of the accumulated Cd was depurated in Cd-free tap water; during the first three days of the uptake period, a negative linear correlation was found between Cd and Zn levels in the snail organs.     

Total sleep deprivation decreases saliva ghrelin levels in adolescents

Ghrelin, a regulator of food intake and energy expenditure, has been shown to be associated with insufficient sleep. The goal of the present study was to investigate the effect of a single night of total sleep deprivation on fasting saliva ghrelin and on nocturnal variation of saliva ghrelin concentration. A further aim of the study was to investigate the influence of body mass index on changes in saliva ghrelin levels. Altogether 35 adolescents (18 boys; age: 13.8 ± 1.14 years) were studied on two subsequent days (sleep and total sleep deprivation). Saliva samples were collected during the two experimental nights at 21:00 hours, 01:00 hours and 06:00 hours. Total-ghrelin concentration showed a continuous increase from the evening until 06:00 hours. This increase was blunted significantly (p = 0.003) by total sleep deprivation. Total-ghrelin level was significantly lower (p = 0.02) during total sleep deprivation at 06:00 hours (median 403.6 pg ml⁻¹; 95% confidence interval: 343.1–468.9 pg ml⁻¹) as compared with values during the sleep condition (median 471.2 pg ml⁻¹; 95% confidence interval: 205.4–1578.7 pg ml⁻¹). Acyl-ghrelin levels did not present any change at the three time points, and were not affected by total sleep deprivation. Stratifying the study population according to body mass index (normal weight and overweight/obese groups), the blunting effect of total sleep deprivation was more pronounced in the obese/overweight group (sleep: median 428.2 pg ml⁻¹; 95% confidence interval: 331.3–606.9 pg ml⁻¹ versus total sleep deprivation: median 333.1 pg ml⁻¹; 95% confidence interval: 261.5–412.9 pg ml⁻¹; p = 0.0479). Saliva total-ghrelin concentrations gradually increased during the night, and total sleep deprivation significantly blunted this increase. This blunting effect was mainly observed in subjects with overweight/obesity. The physiological and clinical implications of the present observation are to be clarified by further studies.