"Stem cell" origin of the hematopoietic defect in dyskeratosis congenita

We have used the long-term bone marrow culture (LTBMC) system to analyze hematopoiesis in three patients with dyskeratosis congenita (DC), two of whom had aplastic anemia, and the third had a normal blood count (apart from mild macrocytosis) and normal BM cellularity. Hematopoiesis was severely defective in all three patients, as measured by a low incidence of colony-forming cells and a low level of hematopoiesis in LTBMC. The function of the marrow stroma was normal in its ability to support the growth of hematopoietic progenitors from normal marrows seeded onto them in all three cases, but the generation of hematopoietic progenitors from patients marrow cells inoculated onto normal stromas was reduced, thus suggesting the defect to be of stem cell origin. The parents and unaffected brother of one of the families have also been studied in LTBMC and all showed normal hematopoietic and stromal cell function. From this study we speculate that there are some similarities between DC and the defect in the W/Wv mouse.     

Inactivation of purified human alpha 2-antiplasmin and purified human C1 inhibitor by synthetic fibrinolytic agents

3-Hydroxypropyl flufenamide (Flu-HPA) is one of a series of flufenamic acid derivatives that enhances blood clot lysis in vitro. Studies of possible mechanisms of action of Flu-HPA were undertaken. The profibrinolytic activity of Flu-HPA in clot lysis assays was found to be dependent on plasminogen. The influence of Flu-HPA on the ability of purified alpha 2-antiplasmin to inhibit purified plasmin was studied. Plasmin activity was determined using 125I-fibrin plates or the spectrophotometric tripeptide substrate, Val-Leu-Lys-paranitroanilide. At Flu-HPA concentrations greater than 1 mM, the inhibitory activity of alpha 2-antiplasmin was abolished in a time-dependent and concentration- dependent manner. The influence of Flu-HPA on the ability of purified Cl inhibitor to inhibit purified plasma kallikrein and beta-Factor XIIa was also studied. Cl inhibitor activity was abolished by Flu-HPA at concentrations greater than 2 mM. Notably, Flu-HPA up to 60 mM did not affect the amidolytic activities of plasmin, kallikrein, or beta-Factor XIIa. Flu-HPA did not release enzyme activity from preformed complexes of either alpha 2-antiplasmin and plasmin of Cl inhibitor and kallikrein. A water-soluble derivative of flufenamic acid, N-flufenamyl- glutamic acid, also inactivated alpha 2-antiplasm and Cl inhibitor. This inactivation was shown to be reversible. These results indicate that synthetic fibrinolytic compounds such as flufenamic acid derivatives may promote fibrinolysis by directly inactivating alpha 2- antiplasmin and Cl inhibitor.     

A novel stop mutation in the EDNRB gene in a family with Hirschsprung’s disease associated with Multiple Sclerosis

Purpose

We identified a girl with Hirschsprung’s disease (HSCR) whose mother and grandmother had HSCR associated with multiple sclerosis (MS). The aim of this study was to outline mutations in HSCR-related genes and MS susceptibility alleles in these three individuals.

Methods

The phenotypes were reviewed based on medical records. The three subjects had rectosigmoid HSCR verified with histopathology. The mother and grandmother fulfilled the McDonald criteria for MS. DNA was isolated from EDTA-preserved blood according to standard procedures. Exome sequencing aiming mainly at analyzing HSCR associated genes as well as Sanger sequencing for confirmation was performed.

Results

All affected individuals carry a novel heterozygous nonsense mutation in the EDNRB gene (c.C397T,p.R133X,refNM_000115), changing an arginine at position 133 into a premature stop codon. None of the subjects were homozygous for the HLA risk alleles for MS.

Conclusion

We report a novel non-sense EDNRB gene mutation in a girl with HSCR and her mother and grandmother with HSCR and MS. We propose that this EDNRB gene mutation plays a role in the etiology of HSCR and also makes the subjects susceptible to MS.     

PCR-Based Detection and Molecular Characterization of Shiga Toxin-Producing Escherichia coli Strains in a Routine Microbiology Laboratory over 16 years

Shiga toxin-producing Escherichia coli (STEC) is a heterogeneous group of bacteria causing disease ranging from asymptomatic carriage and mild infection to hemolytic uremic syndrome (HUS). Here, we describe patients with STEC infection and characterize the STEC strains detected in our laboratory by use of PCR for stx₁, stx₂, and eae from 1996 through 2011. Patient information was collected from referral forms and from the Norwegian Surveillance System for Communicable Diseases. STEC isolates were characterized with respect to serogroup or serotype, selected potential virulence genes, and multilocus variable-number tandem-repeat analysis (MLVA) genotype. STEC strains were isolated from 138 (1.09%) of 12,651 patients tested. STEC strains of serogroups O26, O103, O121, O145, and O157 were the most frequent. These serogroups, except non-sorbitol-fermenting O157, were also the most frequent among the 11 patients (all ≤5 years old) who developed HUS. Twenty-four STEC strains were classified as being HUS associated based on an epidemiological link to a HUS case, including an MLVA genotype identical to that of the STEC strain. The age of the patient (≤5 years) and the genes eae and stx_2a were significantly associated with HUS-associated STEC (P < 0.05 for each parameter), while stx₁ was associated with non-HUS-associated STEC (P < 0.05). All of the potential virulence genes analyzed, except ehxA, were significantly more frequent among HUS-associated than non-HUS-associated strains (P < 0.05 for each gene). However, these genes were also present in some non-HUS-associated STEC strains and could therefore not reliably differentiate between HUS-associated and non-HUS-associated STEC strains.     

Translation and cultural adaptation of the Hirschsprung’s Disease/Anorectal Malformation Quality of life Questionnaire (HAQL) into Swedish

Purpose

Children with anorectal malformation or Hirschsprung’s Disease (HD) often have functional problems with constipation or incontinence. The Hirschsprung’s Disease/Anorectal malformation Quality of life Questionnaire (HAQL) developed in the Netherlands is a disease-specific instrument measuring the quality of life (QoL) of children and adolescents with fecal incontinence. HAQL includes several domains with questions concerning diet, laxatives, constipation, diarrhea, urine and fecal incontinence, in addition to social and emotional functioning, body image, and physical symptoms. The purpose of the study was to translate and culturally adapt the HAQL questionnaire into Swedish.

Method

The translation was carried out according to accepted translation guidelines and a backward/forward translation method was used.

Results

The translation correlated well with the original. All in all the Swedish and the Dutch versions agreed well. The Swedish translators chose to use a more simplified language in the questionnaires intended for the children, but used another choice of words in the proxy version and the adolescents’ version.

Conclusions

The translation of the HAQL instrument into Swedish gives us a disease-specific QoL instrument for children and adolescents born with HD and anorectal malformations (ARM). The translated and culturally adapted HAQL instrument is included in a survey regarding children and adolescents born with ARM.     

The use of 7-amino actinomycin D in identifying apoptosis: simplicity of use and broad spectrum of application compared with other techniques

The detection and quantitation of apoptotic cells is becoming increasingly important in the investigation of the role of apoptosis in cellular proliferation and differentiation. The pathogenesis of hematologic disorders such as aplastic anemia and the development of neoplasia are believed to involve dysregulation of apoptosis. To quantitate accurately the proportion of apoptosis cells within different cell types of a heterogeneous cell population such as blood or bone marrow, a method is required that combines the analysis of large numbers of cells with concurrent immunophenotyping of cell surface antigens. In this study, we have evaluated such a method using the fluorescent DNA binding agent, 7-amino actinomycin D (7AAD), to stain three diverse human cell lines, induced to undergo apoptosis by three different stimuli. Flow cytometric analysis defines three populations on the basis of 7AAD fluorescence and forward light scatter. We have shown by cell sorting and subsequent morphological assessment and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling that the populations defined by 7AAD represent live, apoptotic, and late-apoptotic/dead cells. This method is quick, simple, reproducible, and cheap and will be a valuable tool in the investigation of the role of apoptosis in normal physiology and in disease states.     

参附注射液对左心衰竭病人左心功能的影响

目的探讨参附注射液对慢性左心衰竭病人左心功能的影响.方法选择6例慢性左心衰竭病人,应用SPECT观察参附注射液注射前及注射后5 min、30min、60 min对左心功能各项指标的影响.结果参附注射液注射后较注射前左室射血分数(LVEF)下降(P＜0.05或0.01),以30 min时下降最明显(P＜0.01).结论参附注射液在短时间内能使慢性左心衰竭病人的左心功能下降.