Chemical analysis of compounds extracted from the tergal "spots" of Lutzomyia longipalpis from Brazil

The chemical composition of the compounds contained in the tergal spots of Lutzomyia longipalpis was investigated. Four populations of L. longipalpis were examined, originating from: Sobral, Ceará, Brazil (one spot and two spot populations), Santarém, Pará, Brazil (one spot) and Marajó Island, Pará, Brazil (one spot). The tergal spots were dissected out, extracted in hexane and analysed on a gas chromatograph/mass spectrometer. Two compounds were found, identical to compounds found in earlier studies, but there was no correlation between number of tergal spots and type of compound present. It was suggested that the number of tergal spots could not be used as a marker for reproductively isolated populations, and that analysis of the compound present within the spots might be necessary to characterize potentially good vector populations.     

Mice homozygous for chromosomal deletions at the albino locus region lack specific polypeptides in two-dimensional gels.

Radiation-induced chromosomal deletions involving the albino locus region of the mouse result, when homozygous, in abnormalities ranging from sterility to lethality at various stages of development. We have utilized two-dimensional electrophoresis to search for polypeptide alterations in livers from newborn mice homozygous for the c14CoS and c3H deletions and also from c3H/c6H compound heterozygote mice. Five-hundred polypeptide spots detectable in normal mouse liver gels were scored. Alterations involving five polypeptides were observed in the various overlapping deletions. A spot corresponding to a polypeptide with a 38,000 Mr was missing from mice homozygous for the short c14CoS and the longer overlapping c3H deletions. Another polypeptide with a 29,000 Mr was missing from c3H homozygotes and c3H/c6H heterozygotes. A third polypeptide with a 62,000 Mr was missing only from c3H homozygotes. Two additional polypeptides were markedly increased in amount in c14CoS and c3H homozygotes. The partial overlap between the three deletions analyzed allows provisional genetic mapping of previously unknown loci for three of the five electrophoretically identifiable polypeptides expressed in newborn mouse livers. The results obtained provide a basis for studying radiation-induced deletions with two-dimensional electrophoresis gels.     

Omental milky spots in screening gastric cancer stem cells

The existence of cancer stem and progenitor cells in solid tumors has been widely postulated. However, neither the cancer stem cells nor the cancer progenitor cells have been definitively identified and functionally characterized. Here we propose a new strategy to identify and isolate gastric cancer stem cells -using omental milky spots to screen gastric cancer stem cells in peritoneal metastasis mouse models of gastric cancer. In this study, we used the property that the macrophages in omental milky spots are cytotoxic against tumor cells and so able to screen and collect cancer stem cells. Our findings suggest that macrophages in omental milky spots have not only cytotoxic properties against tumor cells but also provide a microenvironment within milky spots in which cancer stem cells are capable to survive and grow into micrometastasis. Omental milky spot become a cancer stem cell niche in this situation. Further we studied the omental milky spots for screening gastric cancer cells (OMSS-GCCs) and found that omental milky spot enriched the volume of gastric cancer stem cells. Tumors were consistently generated after an injection of 1×103 OMSS-GCCs. OMSS-GCCs high express CD133 and low express CD324. Omental milky spots are a highly efficient "natural filter" for screening gastric cancer stem cells.     

Establishment of permanent chimerism in a lactate dehydrogenase-deficient mouse mutant with hemolytic anemia

Pluripotent hemopoietic stem cell function was investigated in the homozygous muscle type lactate dehydrogenase (LDH-A) mutant mouse using bone marrow transplantation experiments. Hemopoietic tissues of LDH-A mutants showed a marked decreased in enzyme activity that was associated with severe hemolytic anemia. This condition proved to be transplantable into wild type mice (+/+) through total body irradiation (TBI) at a lethal dose of 8.0 Gy followed by engraftment of mutant bone marrow cells. Since the mutants are extremely radiosensitive (lethal dose50/30 4.4 Gy vs 7.3 Gy in +/+ mice), 8.0-Gy TBI followed by injection of even high numbers of normal bone marrow cells did not prevent death within 5-6 days. After a nonlethal dose of 4.0 Gy and grafting of normal bone marrow cells, a transient chimerism showing peripheral blood characteristics of the wild type was produced that returned to the mutant condition within 12 weeks. The transfusion of wild type red blood cells prior to and following 8.0-Gy TBI and reconstitution with wild type bone marrow cells prevented the early death of the mutants and permanent chimerism was achieved. The chimeras showed all hematological parameters of wild type mice, and radiosensitivity returned to normal. It is concluded that the mutant pluripotent stem cells are functionally comparable to normal stem cells, emphasizing the significance of this mouse model for studies of stem cell regulation.     

Alterations of polypeptide composition of mature granulocytes obtained from patients with chronic myelogenous leukemia

In order to compare the polypeptide composition of the CML mature granulocytes with that of the normal whole cell lysates, mature granulocytes from four healthy volunteers and six CML patients were analyzed by two-dimensional gel electrophoresis. In the normal subjects, 60 major spots were commonly and reproducibly identified. In the CML, there were constant alterations in some of these major spots. Four spots were totally absent in all the CML samples, and another four spots were absent in five of the six samples. In addition, one spot was larger in CML than in normal cells, and another spot, which was only faintly visible or not detectable in the normal samples, was massively present in all the CML samples. Our data suggest specific changes in the polypeptide compositions of CML granulocytes. This method could be clinically applied for the analysis of granulocytic disorders.     

Defining wild-type life span in Caenorhabditis elegans

The nematode Caenorhabditis elegans reproduces predominantly as a self-fertilizing hermaphrodite, and this drives laboratory populations to be homozygous at all genetic loci. Passaging of stocks can lead to fixation of spontaneous mutations, especially when the latter do not result in a selective disadvantage under laboratory conditions. Life span may be such a trait, since a comparison of six wild-type N2 lines derived from a common ancestor (but maintained separately in several laboratories) revealed four variants with median adult life spans ranging from 12.0 +/- 0.8 to 17.0 +/- 0.6 days at 20 degrees C. Fertility was also reduced in the two shortest-lived strains. We determined which life span most closely corresponds to that of the authentic wild type by two means. Firstly, N2 hermaphrodites were compared with seven C. elegans wild isolates. The latter were found to resemble only the longest-lived N2 strain. Comparison of male life spans of six lines also revealed additional strain variation. Secondly, life spans of F1 progeny issuing from crosses between N2 variants showed that short life spans were recessive, indicating that they result from loss-of-function mutations. We infer that the longest-lived N2 variant best resembles the original N2 isolate. This is the N2 male stock currently distributed by the Caenorhabditis Genetics Center.     

GPIIb (CD41) integrin is expressed on mast cells and influences their adhesion properties

OBJECTIVES: GPIIb integrin expression has been found on platelets and megakaryocytes, and more recently on immature hematopoietic progenitors. We set out to investigate expression of GPIIb in other hematopoietic cell lineages and, having detected it on mast cells, aimed to determine what possible role it might perform. METHODS: We have made use of cultured human and murine bone marrow mast cells (BMMC) in order to characterize the expression of GPIIb. Further, BMMC cultures from wild type and GPIIb deficient (gpIIb-/-) mice were used for comparison of the adhesive properties mediated by this receptor. Finally, peritoneal mast cells were analyzed from both wild type and (gpIIb-/-) mice. RESULTS: We demonstrate expression of GPIIb on cultured BMMC. Using cells derived from mice homozygous for a null allele of gbIIb we show that the absence of GPIIb has no effect on mast cells with respect to a number of measures of cell growth and differentiation. However, loss of GPIIb on BMMC results in an increase in surface expression of aV integrin, the alternative partner of GPIIIa. CONCLUSION: The results in this study demonstrate that GPIIb is expressed in human and murine mast cells. A function for GPIIb on mast cells is suggested by the altered adhesion of gbIIb-/- BMMC to fibronectin- and vitronectin-coated surfaces. Moreover, comparison of mast cells from the peritoneal cavity of wild type and gbIIb-/- mice indicates that GPIIb could influence the in vivo differentiation or homing of tissue mast cells.     

Identical Twins with the Rhnull Phenotype of the Regulator Type in a Finnish Lapp Family

An inbred family A. G. with identical twin sisters having the Rhnull phenotype of the regulator type as confirmed by the maternal family data of Rh inheritance is reported. The family was traced back through church records for six generations. Several connections could be established with a Norwegian Sea Lapp community in which a family with the amorph Rhnull type has been reported. The closeness of the Finnish and the Norwegian Lapps was given special attention since, despite both of the communities are small and share a more or less common gene pool, they nevertheless seem to possess the two ultra rare Rh genes, Xor in the Finnish and r in the Norwegian family, producing, when homozygous, the Rhnull phenotype.     

Comparison of Nucleolar Proteins of Normal Rat Liver and Novikoff Hepatoma Ascites Cells by Two-Dimensional Polyacrylamide Gel Electrophoresis

A two-dimensional polyacrylamide gel electrophoresis technique is presented for separation of acid-extracted proteins of isolated nucleoli of normal rat liver and Novikoff hepatoma ascites cells. About 100 distinct protein spots were resolved. Comparison of the patterns for normal liver and Novikoff hepatoma revealed nine spots with markedly different intensities in the two patterns. Two spots were found that were unique to the normal liver pattern, and one spot was found that was unique to the hepatoma pattern.     

High-throughput assays for detection of the F1534C mutation in the voltage-gated sodium channel gene in permethrin-resistant Aedes aegypti and the distribution of this mutation throughout Thailand

Objectives To develop rapid monitoring tools to detect the F1534C permethrin‐resistance mutation in domain IIIS6 of the Aedes aegypti voltage‐gated sodium channel gene and determine the frequency and distribution of this mutation in Thailand. Methods A TaqMan SNP genotyping and an allele specific PCR (AS‐PCR) assay were developed and validated by comparison with DNA sequencing of homozygous susceptible and homozygous resistant laboratory strains, their reciprocal‐cross progenies, and field‐caught mosquitoes. To determine the resistance phenotype of wild‐caught A. aegypti, mosquitoes were exposed to 0.75% permethrin paper. The AS‐PCR assay was used to screen 619 individuals from 20 localities throughout Thailand. Results Overall, both assays gave results consistent with DNA sequencing for laboratory strains of known genotype and for wild‐caught A. aegypti. The only slight discrepancy was for the AS‐PCR method, which overestimated the mutant allele frequency by 1.8% in wild‐caught samples. AS‐PCR assays of permethrin‐exposed samples show that the mutant C1534 allele is very closely associated with the resistant phenotype. However, 19 permethrin‐resistant individuals were homozygous for the wild‐type F1534 allele. DNA sequencing revealed all these individuals were homozygous for two other mutations in domain II, V1016G and S989P, which are known to confer resistance ( Srisawat et al. 2010 ). The F1534C mutation is widespread in Thailand with mutant allele frequencies varying among populations from 0.20 to 1.00. Conclusions These assays can be used for the rapid detection of the F1534C resistance mutation in A. aegypti populations. The F1534C, and other, mutations underlie an extremely high prevalence of pyrethroid resistance in Thailand.     

History of non-fatal cardiovascular disease in a cohort of Dutch and British patients with haemophilia

Protein C (PC) deficiency is an autosomal dominant inherited disorder associated with spontaneous and recurrent thrombotic events. Factor V Leiden (FVL) increases the risk of thrombosis in PC-deficient type I families. We have investigated the relationship between PC deficiency genotype and clinical phenotype in a large four-degree Italian family followed since 1988. Methods: PC activity and antigen levels were quantified; sequencing of PC DNA was performed to identify polymorphism. FVL and factor II (G20210A) polymorphism were screened. Results: PC activity ranged from 5% to 9%, and PC antigen levels were 5,3% in two homozygous for PROC missense mutation Arg32Cys; PC activity ranged from 18% to 60% and antigen levels from 21% to 64%, respectively, in 11 heterozygous for Arg32Cys; PC activity was 99% and 120% in two wild type. Of 15, eight were heterozygous for FVL. The two subjects with PC < 6%, homozygous for Arg32Cys and heterozygous for FVL, suffered from thrombosis during childhood. Of 11, six subjects with PC deficiency and heterozygous for FVL showed the first thrombosis at an age between 21 and 54. None of the five PC-deficient subjects, who were wild type for FVL, showed thrombosis. Two subjects with PC > 70%, both heterozygous for FVL developed thrombosis in the presence of another risk factor. This study suggests that FVL and PROC mutations increase the risk of thrombosis in subjects with PC deficiency, which could be considered as a 'variable' risk factor. The thrombosis-prone PC-deficient families carry additional risk factors for thrombosis.     

Two-dimensional polyacrylamide gel electrophoresis analysis of indomethacin-treated human colon cancer cells

AIM: To establish the two-dimensional gel electrophoresis (2-DE) profiles of indomethacin (IN)-treated human colon cancer cell line HCT116, and to provide a new way to study its anti-tumor molecular mechanism through analyzing a variety of protein maps. METHODS: Two-DE profiles of HCT116 were established in IN-treated and untreated groups. Total proteins were separated by immobilized pH gradient-based 2-DE. The gels were stained by silver, scanned by ImageScanner, and analyzed with Image Master software. RESULTS: Clear background, well-resolved and reproducible 2-DE patterns of HCT116 cells were acquired in IN-treated and untreated group. The average deviation of spot position was 0.896±0.177 mm in IEF direction and 1.106±0.289 mm in SDS-PAGE direction respectively. In IN-treated group, 1169±36 spots were detected and 1 061±32 spots were matched, the average matching rate was 90.6% in three gels. In untreated group, 1 256±50 spots were detected and 1168±46 spots were matched, the average matching rate was 93.0% in three gels. Forty-five differential protein spots were displayed between IN-treated and untreated groups. Of which, 34 protein spots decreased and 9 showed higher expression in IN-treated group, and only two protein spots showed an expression in untreated cells. CONCLUSION: Two-DE profiles of IN-treated and untreated HCT116 cells were established. Apparent 45 different protein spots were detected in IN-treated and untreated HCT116 cells. The analysis on differential protein spots may serve as a new way to study the molecule mechanism of IN-treated colon cancer.     

Factor XDebrecen: Gly204Arg mutation in factor X causes the synthesis of a non-secretable protein and severe factor X deficiency

Due to a homozygous Gly204Arg mutation in the factor X (FX) gene no detectable FX antigen was found in the plasma of a one-year old patient with severe bleeding diathesis. The amino acid replacement destabilized the disulfide bond that holds the two FX chains together, decreasing the interaction between the Cys201-Cys206 loop region and the region connecting the EGF2 and serine protease domains. Both Gly204 FX and Arg204 FX were synthesized in transfected cells, but only the wild type protein became secreted. The mutant protein was diverted from the normal secretory pathway and retained at the trans Golgi-late endosome level.     

Granulocytic nuclear differentiation of lamin B receptor-deficient mouse EPRO cells

OBJECTIVE: Lamin B receptor (LBR) is an integral protein of the inner nuclear membrane. Recent studies have demonstrated that genetic deficiency of LBR during granulopoiesis results in hypolobulation of the mature neutrophil nucleus, as observed in human Pelger-Hu?t anomaly and mouse ichthyosis (ic). In this study, we utilized differentiated early promyelocytes (EPRO cells) that were derived from the bone marrow of homozygous and heterozygous ichthyosis mice to examine changes to the expression of nuclear envelope proteins and heterochromatin structure that result from deficient LBR expression. MATERIALS AND METHODS: Wild-type (+/+), heterozygous (+/ic), and homozygous (ic/ic) granulocytic forms of EPRO cells were analyzed for the expression of multiple lamins and inner nuclear envelope proteins by immunostaining and immunoblotting techniques. The heterochromatin architecture was also examined by immunostaining for histone lysine methylation. RESULTS: Wild-type (+/+) and heterozygous (+/ic) granulocytic forms revealed ring-shaped nuclei and contained LBR within the nuclear envelope; ic/ic granulocytes exhibited smaller ovoid nuclei devoid of LBR. The pericentric heterochromatin of undifferentiated and granulocytic ic/ic cells was condensed into larger spots and shifted away from the nuclear envelope, compared to +/+ and +/ic cell forms. Lamin A/C, which is normally not present in mature granulocytes, was significantly elevated in LBR-deficient EPRO cells. CONCLUSIONS: Our observations suggest roles for LBR during granulopoiesis, which can involve augmenting nuclear membrane growth, facilitating compartmentalization of heterochromatin, and promoting downregulation of lamin A/C expression.     

Inherited HFE-unrelated hemochromatosis in Italian families

Hemochromatosis (HH) is usually caused by the homozygous state for C282Y mutation in the HFE gene. A minority of iron loaded patients have no mutations in this gene. An infrequent subset shows an early-onset aggressive disorder, denoted juvenile hemochromatosis (JH), which has no linkage to 6p. In this report we describe six patients from three unrelated Italian families, four men and two women, aged 21 to 44 with the typical hemochromatosis phenotype, who are homozygous for the wild type allele at the HFE gene. In two families the disorder is unlinked to 6p; in one family some features of the juvenile form are seen, but linkage to 6p is not excluded. Our results point to genetic forms of hemochromatosis not associated with HFE and raise the problem of whether non-HFE hemochromatosis in Italy is related to the "juvenile" form. They also emphasize the importance of phenotypic as well as genetic diagnosis of HH.     

氨基糖甙类药物恢复HERG通道无义突变体的功能

目的本研究旨在探讨氨基糖甙类药物对纯合和杂合的HERG无义突变体的作用效应。方法采用聚合酶链反应法制备HERGR1014X突变体,并克隆至真核细胞表达载体中。将突变体的cDNA瞬时转染至HEK293细胞,应用全细胞膜片钳技术记录通道电流。药物拯救采用将转染24h后的HEK293细胞在含G-418或庆大霉素(终浓度为400μg/mL)的培养液中孵育24h。结果 R1014X能表达典型的HERG样电流,尽管与野生型(wildtype,WT)HERG相比,最大尾电流幅值明显下降(3.9±1.4pA/pF,n=8,vs.47.8±6.3pA/pF,n=12,P0.01)。经过G-418和庆大霉素干预后,R1014X的最大尾电流密度分别增加至12.7±3.3pA/pF(n=7,P0.05)和18.3±3.7pA/pF(n=8,P0.05)。药物干预使R1014X的激活动力学特性亦得到恢复。Westernblot和共聚焦检测进一步证实,氨基糖甙类能促进全长的HERG通道蛋白的表达。G-418和庆大霉素对杂合的WT/R1014X通道作用效应不同:庆大霉素能使WT/R1014X的电流增加2.2倍(n=12,P0.05),G-418却无明显效应。结论氨基糖甙类药物能恢复无义突变的HERG通道的功能性表达,且对纯合和杂合通道均有效,这为遗传性心律失常的治疗提供了新的思路。     

The impact of single nucleotide polymorphisms of the thrombin activatable fibrinolysis inhibitor (TAFI) gene on TAFI antigen levels in healthy children and pediatric oncology patients

The thrombin activatable fibrinolysis inhibitor (TAFI) influences the pathways regulating fibrin formation and deposition. The enormous TAFI plasma level variability present in adults may be explained by a combination of two polymorphisms in the TAFI gene (+1542C>G; 505G>A). We aimed to correlate these two polymorphisms with plasma TAFI antigen concentrations in healthy children and pediatric oncology patients with and without venous thrombosis who were supplied with Broviac central venous catheters. Polymorphisms were detected by restriction fragment length polymorphism (RFLP) analysis of polymerase chain reaction (PCR) amplification, whereas TAFI concentration was determined using a commercial enzyme-linked immunosorbent assay (ELISA). Samples from 57 controls and 67 pediatric patients (11 venous thrombotic complications) were studied. TAFI levels in healthy children and patients were not influenced by gender or age. Compared with the 505GG carriers (wild type), 505AA carriers as well as heterozygous 505GA carriers each exhibited significantly higher TAFI antigen concentrations. In contrast, the lowest TAFI levels were detected in homozygous carriers of the +1542GG polymorphism. A combination of the genotype 505AA (homozygous carrier) and +1542CC (wild type) was present in 13 probands and resulted in the highest TAFI levels. Although in oncologic patients the risk of thrombosis was markedly increased by the heterozygous factor V 1691G>A mutation, the two TAFI polymorphisms investigated exerted no thrombogenic influence.