糖皮质激素对哮喘患者白细胞介素-5mRNA表达与嗜酸性粒细胞激活作用的影响

为了观察糖皮质激素对哮喘患者白细胞介素（ＩＬ）－５ｍＲＮＡ表达与嗜酸性粒细胞激活作用的影响，本研究用逆转录（ＲＴ）－聚合酶链反应（ＰＣＲ）法半定量分析了哮喘患者用糖皮质激素治疗前后外周血单个核细胞（ＰＢＭＣ）中ＩＬ－５ｍＲＮＡ表达水平的变化，检测了血清嗜酸细胞阳离子蛋白（ＥＣＰ）浓度、一秒钟用力呼气容积（ＦＥＶ１）下降２０％时的乙酰甲胆碱（ＭＣＨ）激发浓度（ＭＣＨ－ＰＣ２０值）和基础ＦＥＶ１占用力肺活量比值（ＦＥＶ１％）等指标。结果发现，糖皮质激素不仅能改善哮喘患者的气道高反应性和通气功能，而且还可抑制ＰＢＭＣ中ＩＬ－５ｍＲＮＡ的表达和降低血清ＥＣＰ浓度（Ｐ＜０．０５）；血清ＥＣＰ浓度下降幅度或ＭＣＨ－ＰＣ２０值改善幅度与ＩＬ－５ｍＲＮＡ表达水平下降幅度之间均呈显著正相关（ｒ分别为０．５４２６和０．４８５７，Ｐ值＜０．０５）。提示糖皮质激素可能是通过抑制ＩＬ－５基因的转录，从而抑制后者对嗜酸性粒细胞的活化，而发挥其抗气道炎症反应和降低气道高反应性的作用。     

Are microproerythroblasts in human bone marrow real or artefacts? A cytochemical note

Early erythroid precursors were studied in human bone marrow smears to provide more information on small proerythroblasts--"microproerythroblasts"--using a silver reaction to demonstrate silver stained nucleolar organizer regions (AgNORs) and light microscopic densitometry of large irregularly shaped nucleoli and cytoplasm stained for RNA. No significant differences were found for the density of such nucleoli and basophilic cytoplasm between characteristic large proerythroblasts with a nuclear diameter larger that 9 microm (K2 and K1 erythroblasts) and small proerythroblasts--"microproerythroblasts" representing a subpopulation of K1/2 erythroblasts (early basophilic erythroblasts), which are characterized by a smaller nuclear diameter. In addition, large irregularly shaped nucleoli of "microproerythroblasts" possessed numerous silver stained particles representing AgNORs similar to those of large proerythroblasts. The number of AgNORs in "microproerythroblasts" was slightly, but significantly, smaller than that in large characteristic proerythroblasts.     

Molecular epidemiology of norovirus variants detected in children under five years of age in Hyderabad,India

PurposeNoroviruses are common viral agents in acute diarrhea in all age groups worldwide. Norovirus has been classified into 10 genogroups, GI to GX with over 48 genotypes among them the GII.4 genotype has evolved over time with a clear pattern of periodic variant replacement. Immunity is strain or genotype specific with little or no protection conferred across genogroups. The present study was aimed to determine the epidemiology, prevalent genotypes of norovirus in children below five years of age in the Hyderabad region, India.MethodsThe stool samples and clinical data were collected from 458 children below 5 years of age comprising of cases with acute gastroenteritis (n ?= ?366) and a control group (n ?= ?92) admitted to the pediatric ward. All the samples were tested for Norovirus by ELISA and RT-PCR. Sequencing was done for predominant strains.Results10.3% (n ?= ?38) of cases and 3.2% (n ?= ?3) of the control group were found to be Norovirus positive. Predominant genotypes were GII-82.5% followed by GI-12.5%.ConclusionSequencing and Phylogenetic analyses of 20 GII.4 strains was done. All of the isolates are clustered away from published the GII.4 variants thus suggesting the appearance of a new variant.     

The search for a marsupial XIC reveals a break with vertebrate synteny

X-chromosome inactivation (XCI) evolved in mammals to deal with X-chromosome dosage imbalance between the XX female and the XY male. In eutherian mammals, random XCI of the soma requires a master regulatory locus known as the ‘X-inactivation center’ (XIC/Xic), wherein lies the noncoding XIST/Xist silencer RNA and its regulatory antisense Tsix gene. By contrast, marsupial XCI is imprinted to occur on the paternal X chromosome. To determine whether marsupials and eutherians share the XIC-driven mechanism, we search for the sequence equivalents in the genome of the South American opossum, Monodelphis domestica. Positional cloning and bioinformatic analysis reveal several interesting findings. First, protein-coding genes that flank the eutherian XIC are well-conserved in M. domestica, as well as in chicken, frog, and pufferfish. However, in M. domestica we fail to identify any recognizable XIST or TSIX equivalents. Moreover, cytogenetic mapping shows a surprising break in synteny with eutherian mammals and other vertebrates. Therefore, during the evolution of the marsupial X chromosome, one or more rearrangements broke up an otherwise evolutionarily conserved block of vertebrate genes. The failure to find XIST/TSIX in M. domestica may suggest that the ancestral XIC is too divergent to allow for detection by current methods. Alternatively, the XIC may have arisen relatively late in mammalian evolution, possibly in eutherians with the emergence of random XCI. The latter argues that marsupial XCI does not require XIST and opens the search for alternative mechanisms of dosage compensation.     

Intraaxonaler transport von Ethidium-Bromid-sensitiven RNS- und niedermolekularen 3H-Uridin-Verbindungen im tractus opticus von teleosteern

Zusammenfassung Am Sehtrakt von Carassius carassius und Scardinius erythrophthalmus wurde die axonale Ausbreitungsweise hoch- und niedermolekularer 3H-Uridin-Verbindungen untersucht. Dabei wurde nach intraocularer Injektion des Tracers für TCE-resistente Verbindungen eine intraaxonale Transportgeschwindigkeit von 2–4 mm/d bestimmt, für TCE-lösliche Verbindungen eine von ca. 30–50 mm/d. Durch Applikation des spezifisch mitochondrialen RNS-Synthese-Hemmers Ethidium-Bromid konnte die Einbaurate von 3H-Uridin in hochmolekulare RNS um 70–80% erniedrigt werden, was dafür spricht, daß die langsam im Axoplasma wandernden Mitochondrien einen Großteil der axonalen RNS synthetisieren.In der TCE-löslichen Fraktion konnten durch dünnschichtchromatographische Analyse noch nach 8d p. i. 3H-Uridin und 3H-UDPG nachgewiesen werden. Dieser Befund wird hinsichtlich eines transneuronalen Stoffübertritts von Uridin und der möglichen Bedeutung des UDPG-Transportes im Nervengewebe diskutiert.

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Intraaxonal transport of ethidium-bromide-sensitive RNA- and lowmolecular 3H-uridine-compounds in the optic tract of teleost

Summary In the optic system of teleosts (Carassius carassius and Scardinius erythrophthalmus) the axonal flow of high and low molecular 3H-uridine-compounds was investigated. After injection of the tracer into one eyeball and TCA-extraction of the samples a transport-rate of 2–4 mm/d was demonstrated. By the specific inhibitor of mitochondrial RNA-synthesis, Ethidium-Bromide, the amount of axonal radioactivity could be reduced to 20–30% of the control. This indicates the mitochondria as being the site of synthesis most of axonal RNA. Considering the TCA-soluble 3H-uridine-compounds, an intraaxonal flow also could be demonstrated, with a transport-rate of 30–50 mm/d, 16 times higher as the one of RNA. The analysis by thin layer chromatography indicated the existence of 3H-uridine and 3H-UDPG in the axonal fraction of TCA-soluble compounds still after an incorporation time of 8d. The possibility of a transneuronal convection of uridine and the function of UDPG-transport in the axon are discussed.

Frau Prof. Dr. H. Kersten (Erlangen) danke ich für die Überlassung einer Probe Ethidium-Bromid.     

Isolation and RNA-binding analysis of NAD+-isocitrate dehydrogenases from Kluyveromyces lactis and Schizosaccharomyces pombe

Krebs cycle NAD⁺-isocitrate dehydrogenase (Idh) binds to the 5-UTRs of all mitochondrial mRNAs in Saccharomyces cerevisiae. We hypothesize that this leader-binding activity plays a role in translational regulation, thereby linking mitochondrial biogenesis to the need for respiratory function. Analysis of effects of leader binding on mitochondrial translation is complicated by the involvement of the enzyme in mitochondrial metabolism. We have therefore searched for an Idh altered in RNA binding, but retaining full enzyme activity. Idh from Kluyveromyces lactis and Schizosaccharomyces pombe was partially purified and examined for the ability to bind Cox2 mRNA. Sch. pombe Idh, like the S. cerevisiae enzyme, has high affinity for both its own, K. lactis and S. cerevisiaeCOX2 leaders. In contrast, Idh purified from K. lactis shows only low affinity for all mRNAs tested. To determine what distinguishes K. lactis Idh from S. cerevisiae Idh, genes encoding the two subunits of Idh in K. lactis were cloned and sequenced. Sequence comparison revealed high levels of similarity throughout the proteins, in particular in regions involved in enzyme activity, co-factor and regulator binding. Non-conserved residues between the subunits from the two yeasts are candidates for involvement in the interaction with RNA. Received: 19 January 2000 / 24 March 2000     

Clinical significance of antibodies to nonstructural and core proteins of hepatitis C virus in posttransfusion hepatitis patients during long-term follow-up

The prevalence of hepatitis C antibodies (anti- HCV) among multitransfused patients was studied and compared with predicted values obtained from a post-transfusion hepatitis study and from data on the prevalence of anti-HCV among blood donors. The prevalence of hepatitis B core antibodies (anti-HBc) was also studied to determine the routes of transmission of hepatitis C virus. The patients consisted of 65 dialysis patients (57 on haemodialysis and 8 on continuous ambulatory peritoneal dialysis) and 71 leukemia patients in long-term remission [49 with acute myeloid leukemia (AML) and 22 with acute lymphatic leukemia (ALL)]. The presence of anti-HCV was investigated using a second generation enzyme-linked immunosorbent assay. Reactive samples were confirmed by a second generation recombinant immunoblot assay. Anti-HBc was studied in the 65 dialysis patients and in 40 of the leukemia patients. Three (4.6%) of the 65 dialysis patients and 12 (24.5%) of the 49 AML patients were anti-HCV positive whereas all of the ALL patients were seronegative. The total number of blood units transfused to 134 patients (data on two dialysis patients were not available) was 18,148, out of which 17,575 units had been transfused prior to the initiation of anti- HCV screening of blood donors. On the basis of the anti-HCV prevalence among blood donors and the incidence of post-transfusion hepatitis, the predicted number of seropositive patients was 11 and 18, respectively. Five of the 65 dialysis patients were anti-HBc positive, compared with only one of the 40 leukemia patients. It is concluded that the anti-HCV prevalence among dialysis and leukemia patients is concordant with the risk of receiving contaminated blood products, whereas hepatitis B infection may have other routes of transmission in dialysis patients. © 1993 Wiley-Liss, Inc.