Transplantation of human placental chorionic plate-derived mesenchymal stem cells for repair of neurological damage in neonatal hypoxic-ischemic encephalopathy

Neonatal hypoxic-ischemic encephalopathy is often associated with permanent cerebral palsy,neurosensory impairments,and cognitive deficits,and there is no effective treatment for complications related to hypoxic-ischemic encephalopathy.The therapeutic potential of human placental chorionic plate-derived mesenchymal stem cells for various diseases has been explored.However,the potential use of human placental chorionic plate-derived mesenchymal stem cells for the treatment of neonatal hypoxic-ischemic encephalopathy has not yet been investigated.In this study,we injected human placental chorionic plate-derived mesenchymal stem cells into the lateral ventricle of a neonatal hypoxic-ischemic encephalopathy rat model and observed significant improvements in both cognitive and motor function.Protein chip analysis showed that interleukin-3 expression was significantly elevated in neonatal hypoxic-ischemic encephalopathy model rats.Following transplantation of human placental chorionic plate-derived mesenchymal stem cells,interleukin-3 expression was downregulated.To further investigate the role of interleukin-3 in neonatal hypoxic-ischemic encephalopathy,we established an in vitro SH-SY5Y cell model of hypoxic-ischemic injury through oxygen-glucose deprivation and silenced interleukin-3 expression using small interfering RNA.We found that the activity and proliferation of SH-SY5Y cells subjected to oxygen-glucose deprivation were further suppressed by interleukin-3 knockdown.Furthermore,interleukin-3 knockout exacerbated neuronal damage and cognitive and motor function impairment in rat models of hypoxic-ischemic encephalopathy.The findings suggest that transplantation of hpcMSCs ameliorated behavioral impairments in a rat model of hypoxic-ischemic encephalopathy,and this effect was mediated by interleukin-3-dependent neurological function.

MicroRNA-298 determines the radio-resistance of colorectal cancer cells by directly targeting human dual-specificity tyrosine(Y)-regulated kinase 1A

BACKGROUND Radiotherapy stands as a promising therapeutic modality for colorectal cancer(CRC);yet,the formidable challenge posed by radio-resistance significantly undermines its efficacy in achieving CRC remission.AIM To elucidate the role played by microRNA-298(miR-298)in CRC radio-resistance.METHODS To establish a radio-resistant CRC cell line,HT-29 cells underwent exposure to 5 gray ionizing radiation that was followed by a 7-d recovery period.The quantification of miR-298 levels within CRC cells was conducted through quantitative RT-PCR,and protein expression determination was realized through Western blotting.Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and proliferation by clonogenic assay.Radio-induced apoptosis was discerned through flow cytometry analysis.RESULTS We observed a marked upregulation of miR-298 in radio-resistant CRC cells.MiR-298 emerged as a key determinant of cell survival following radiation exposure,as its overexpression led to a notable reduction in radiation-induced apoptosis.Intriguingly,miR-298 expression exhibited a strong correlation with CRC cell viability.Further investigation unveiled human dual-specificity tyrosine(Y)-regulated kinase 1A(DYRK1A)as miR-298’s direct target.CONCLUSION Taken together,our findings underline the role played by miR-298 in bolstering radio-resistance in CRC cells by means of DYRK1A downregulation,thereby positioning miR-298 as a promising candidate for mitigating radioresistance in CRC.

Induction of Human Anti-Human Antibody Responses (Ab2) after Application of a Humanized Lewis Y Carbohydrate Specific Antibody (Ab1): Connection of Prolonged Disease Stabilization with Ab3 Induction?

Purpose: Detailed analysis of a patient with epithelial Lewis Y (LeY) positive cancer who received twice 50 mg of the humanized Lewis Y carbohydrate specific mAb IGN311 and developed a clinically significant human anti-human antibody (HAHA) response (Ab2). Results: Clinical stabilization of the disease was assigned to in this patient. The HAHA response consisted mainly of IgG1 and was found to be directed against the IGN311 binding site. Consistent with the induction of the HAHA response, CDC activity against Lewis Y positive target cells was completely abolished at day 8 and could not be restored by the second 50 mg infusion indicating complete neutralization of applied IGN311. The ADCC reactivity was also significantly reduced and anti-anti idiotype-specific antibodies (Ab3) were detectable at day 65. Conclusions: Induction of Ab3 antibodies should be considered as an additional factor influencing the efficacy of humanized antibodies. In this context, the potential threat of induced HAHA responses against therapeutic mAbs might have to be reconsidered because they might actually have also beneficial immunological long-term effects leading to an active immunization component induced by therapeutic antibodies.

Relationship between chromosome behaviour and stability of human-mouse and human-(human-mouse)hvbridomas

Chromosomes in human-mouse and human-(human-mouse)hybridomas wereanalysed by G-banding methods.It was found that most human chromosomes,exceptNo.13 and X,Y,were retained.The frequencies of chromosomes No.1,3,4,5,6,17,19,21 and 22 were higher than those of other chromosomes in each hybridoma clone.The myeloma cell lines X63-Ag8.653 and SHM-D33 were also analysed.The morphologyof marker chromosomes was apparently different between hybridomas.There were 7 kindsof marker chromosomes in human-mouse hybridomas and 16 kinds of markerchromosomes in human-(human-mouse)hybridomas.Clones that retained humanchromosome No.1 were more stable and clones that did not retain human chromosomeNo.14 were still capable of secreting human immunoglobulin.Clones that retained humanchromosome No.2 did not secret human k light chain McAb while clones that retainedhuman chromosomes No.2 and No.22 only secreted λ light chain.

Effects of hepatitis B virus infection on human sperm chromosomes

AIM: To evaluate the level of sperm chromosome aberrations in male patients with hepatitis B, and to directly detect whether there are HBV DNA integrations in sperm chromosomes of hepatitis B patients.METHODS: Sperm chromosomes of 14 tested subjects (5healthy controls, 9 patients with HBV infection, including 1with acute hepatitis B, 2 with chronic active hepatitis B, 4with chronic persistent hepatitis B, 2 chronic HBsAg carriers with no clinical symptoms) were prepared using interspecific in vitro fertilization between zona-free golden hamster ova and human spermatozoa, and the frequencies of aberration spermatozoa were compared between subjects of HBV infection and controls. Fluorescence in situ hybridization (FISH) to sperm chromosome spreads was carried out with biotin-labeled full length HBV DNA probe to detect the specific HBV DNA sequences in the sperm chromosomes.RESULTS: The total frequency of sperm chromosome aberrations in HBV infection group (14.8%, 33/223) was significantly higher than that in the control group (4.3%,5/116). Moreover, the sperm chromosomes in HBV infection patients commonly presented stickiness, clumping, failure to staining, etc, which would affect the analysis of sperm chromosomes. Specific fluorescent signal spots for HBV DNA were seen in sperm chromosomes of one patient with chronic persistent hepatitis. In 9 (9/42) sperm chromosome complements containing fluorescent signal spots, one presented 5 obvious FISH spots, others presented 2 to 4signals. There was significant difference of fluorescence intensity among the signal spots. The distribution of signal sites among chromosomes was random.CONCLUSION: HBV infection can bring about mutagenic effects on sperm chromosomes. Integrations of viral DNA into sperm chromosomes which are multisites and nonspecific, can further increase the instability of sperm chromosomes. This study suggested that HBV infection can create extensively hereditary effects by alteration genetic constituent and/or induction chromosome aberrations, as well as the possibility of vertical transmission of HBV via the germ line to the next generation.

Phase I Dose Escalation Study with the Lewis Y Carbohydrate Specific Humanized Antibody IGN311

Purpose: Investigation of safety, tolerability, pharmacokinetics, and anti-tumor activity of the Lewis Y-specific, fully humanized monoclonal antibody (mAb) IGN311 in patients with Lewis Y positive tumors in a Phase I clinical trial. Experimental Design: Twelve patients (pts) were enrolled in an open-label, uncontrolled, dose escalating Phase I study. Three pts received 50 mg, three pts 100 mg and six pts 200 mg IGN311 by i.v. infusion on days 1 and 15. Blood samples were taken immediately before infusion, and 0.5, 4, 8, 24 hours post infusion, as well as on days 3, 5 and 8 after the first and second infusion, respectively, and day 29. A final visit was scheduled for day 43. Results: No drug related adverse events were observed in the 50 mg and 100 mg dose groups. Three out of six patients in the 200 mg dose group showed drug related adverse reactions with nausea, vomiting and hypotension in one patient (NCI CTC grade 3) being the dose limiting toxicities. t1/2 of IGN311 was ~20 days after second infusion of IGN311. Sera of patients receiving IGN311 were capable of lysing Lewis Y positive tumor cells in vitro by both, complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC). Circulating tumor cells found in the peripheral blood in two out of twelve pts prior to treatment were reduced after treatment to below the quantification limit of the detection method. None of the patients showed an increase in the number of disseminated tumor cells during treatment period. Conclusions: The good safety and PK profile, the biological activity regarding CDC and ADCC mediated tumor cell lysis, and the elimination of circulating tumor cells warrant further clinical investigation of IGN311.

Molecular Profile of Human Serine Palmitoyltransferase-1 Proximate of Chromosome 9 Disease Susceptibility Gene Cluster in Inflammatory Cancer Cell Lines

Background: Over 1100 genes have been annotated for human chromosome 9, including disease genes implicated in inflammation, atherosclerosis, cancer and neurodegeneration. The serine palmitoyltransferase-1, SPTLC1, gene is at the 9q22.2 cytogenetic band, a high G+C content region with common genetic alterations sufficient to modify cellular behavior. The sequence is highly conserved among diverse species from bacteria to humans, including a recently discovered 126 nucleotide alternate open reading frame, AltORF. The protein encoded by the reading frames has domains of biological interest and considerable overlapping molecular functions associated with cellular behavior and cancer progression. Methods: Here we examined molecular features of SPTLC1 in a group of inflammation associated cancer cell lines SKN-SH, MDA-PCa, Glioma LN18, PC3 and 647V. Subcellular localization of SPTLC1 was assessed by immunofluorescence microscopy and recombinant green fluorescent protein expression. In addition, PCR, DNA sequencing and bioinformatics analysis were used for molecular profiling of the SPTLC1 genomic and reverse transcribed cDNA fragments. Results: SPTLC1 is detected in all cell lines examined, with intense peri-nuclear staining, consistent with localization in the cytoplasm. Genomic DNA sample, but not the cD NA of SKN cells could be amplified with an AltORF primer set. The PC3 and MDA-PCa cancer cell lines which are both of prostate origin, show differences in SPTLC1 PCR amplification. Similar levels of SPTLC1 AltORF transcripts were detected by quantitative RT-PCR in all cell lines, except the PC3 cell line with low transcript level whose cDNA did not generate nucleotide base sequence information. Conclusions: This is the first reported transcriptional expression of the SPTLC1 AltORF for the inflammation associated human cancer cell lines. Interestingly, it is proximate of oncogenic cancer susceptibility genes and distal of tumor suppressor genes, the high content of short nucleotide repeats in the SPTLC1 AltORF sequence suggesting the region may be genetically unstable. This nominal functional genomics report on the human SPTLC1 AltORF will contribute to compiling a more detailed SPTLC1 gene ontology and is expected to help shed more insight into unique molecular attributes of SPTLC1 in the context of cancer cell behavior, malignant progression and the design of treatment for inflammation associated cancers.

Repeat Sequences and Base Correlations in Human Y Chromosome Palindromes

On the basis of information theory and statistical methods, we use mutual information, n- tuple entropy and conditional entropy, combined with biological characteristics, to analyze the long range correlation and short range correlation in human Y chromosome palindromes. The magnitude distribution of the long range correlation which can be reflected by the mutual information is PS〉PSa〉PSb （P5a and P5b are the sequences that replace solely Alu repeats and all interspersed repeats with random uneorrelated sequences in human Y chromosome palindrome 5, respectively）; and the magnitude distribution of the short range correlation which can be reflected by the n-tuple entropy and the conditional entropy is PS〉P5a〉PSb〉random uncorrelated sequence. In other words, when the Alu repeats and all interspersed repeats replace with random uneorrelated sequence, the long range and short range correlation decrease gradually. However, the random nncorrelated sequence has no correlation. This research indicates that more repeat sequences result in stronger correlation between bases in human Y chromosome. The analyses may be helpful to understand the special structures of human Y chromosome palindromes profoundly.

Detection of ROS and translocation of ERP-57 in apoptotic induced human neuroblastoma(SH-SY5Y)cells

Several toxic compounds are known to induce apoptosis in mammalian cell lines.The human neuroblastoma cells(SHSH-SY5Y)were exposed to the phosphatase inhibiting toxin okadaic acid(OA)or hydrogen peroxide(H2O2)to induce apoptosis as well as generate reactive oxygen species(ROS).Mitoxantrone(MXT)was used as a positive control for apoptosis.The SHSH-SY5Y cells were transfected with eukaryotic expression plasmid pHyPer-dMito encoding mitochondrial-targeted fluorescent or pHyPer-dCito encoding cytoplasmic-targeted fluorescent sensor for hydrogen peroxide(HyPer).The ERp57,also called GRP58(Glucose-regulated protein 58),is a stress protein induced in conditions like glucose starvation and viral infection.Recently ERp57 was shown to translocate from the endoplasmatic reticulum to the cell surface in anthracycline-induced apoptotic cells.ERp57 co-translocation together with calreticulin has been suggested to be crucial for recognizing tumor cells to induce immunogenic cell death.ERp57 translocation after exposure to okadaic acid was studied using immunofluorescence and confocal microscopy.These studies indicated that okadaic acid has induced the translocation of ERp57 to the cellular membrane.

Studies on the integration of hepatitis B virus DNA sequence in human sperm chromosomes

Aim: To study the integration of hepatitis B virus (HBV) DNA into sperm chromosomes in hepatitis B patients and the features of its integration. Methods: Sperm chromosomes of 14 subjects (5 healthy controls and 9 HB patients, including 1 acute hepatitis B, 2 chronic active hepatitis B, 4 chronic persistent hepatitis B, 2 HBsAg chronic carriers with no clinical symptoms) were prepared using interspecific in vitro fertilization between zona-free hamster oocytes and human spermatozoa. Fluorescence in situ hybridization (FISH) to sperm chromosome spreads was carried out with biotin-labeled full length HBV DNA probe to detect the specific HBV DNA sequences in the sperm chromosomes. Results: Specific fluorescent signal spots for HBV DNA were seen in sperm chromosomes of one patient with chronic persistent hepatitis B. In 9(9/42) sperm chromosome complements containing fluorescent signal spots, one presented 5 obvious FISH spots and the others 2 to 4 signals. The fluorescence intensity showed significant difference among the signal spots. The distribution of signal sites among chromosomes seems to be random. Conclusion: HBV could integrate into human sperm chromosomes. Results suggest that the possibility of vertical transmission of HBV via the germ line to the next generation is present.

"Micro-deletions" of the human Y chromosome and their relationship with male infertility

The Y chromosome evolves from an autochromosome and accumulates male-related genes including sex-determining region of Y-chromosome （SRY） and several spermatogenesis-related genes. The human Y chromosome （60 Mb long） is largely composed of repetitive sequences that give it a heterochromatic appearance, and it consists of pseudoautosomal, euchromatic, and heterochromatic regions. Located on the two extremities of the Y chromosome, pseudoautosomal regions 1 and 2 （PAR1 and PAR2, 2.6 Mb and 320 bp long, respectively） are homologs with the termini of the X chromosome. The euchromatic region and some of the repeat-rich heterochromatic parts of the Y chromosome are called ＂male-specific Y＂ （MSY）, which occupy more than 95% of the whole Y chromosome. After evolution, the Y chromosome becomes the smallest in size with the least number of genes but with the most number of copies of genes that are mostly spermatogenesis-related. The Y chromosome is characterized by highly repetitive sequences （including direct repeats, inverted repeats, and palindromes） and high polymorphism. Several gene rearrangements on the Y chromosome occur during evolution owing to its specific gene structure. The consequences of such rearrangements are not only loss but also gain of specific genes. One hundred and fifty three haplotypes have been discovered in the human Y chromosome. The structure of the Y chromosome in the GenBank belongs to haplotype R1. There are 220 genes （104 coding genes, 111 pseudogenes, and 5 other uncategorized genes） according to the most recent count. The 104 coding genes encode a total of about 48 proteins/protein families （including putative proteins/protein families）. Among them, 16 gene products have been discovered in the azoospermia factor region （AZF） and are related to spermatogenesis. It has been discovered that one subset of gene rearrangements on the Y chromosome, ＂micro-deletions＂, is a major cause of male infertility in some populations. However, controversies exist about different Y chromosome haplotypes. Six AZFs of the Y chromosome have been discovered including AZFa, AZFb, AZFc, and their combinations AZFbc, AZFabc, and partial AZFc called AZFc/gr/gr. Different deletions in AZF lead to different content spermatogenesis loss from teratozoospermia to infertility in different populations depending on their Y haplotypes. This article describes the structure of the human Y chromosome and investigates the causes of micro-deletions and their relationship with male infertility from the view of chromosome evolution. After analysis of the relationship between AZFc and male infertility, we concluded that spermatogenesis is controlled by a network of genes, which may locate on the Y chromosome, the autochromosomes, or even on the X chromosome. Further investigation of the molecular mechanisms underlying male fertility/infertility will facilitate our knowledge of functional genomics.

ISOBUTYRAMIDE ACTIVATES TRANSCRIPTION OF HUMAN FETAL γ-AND MURINE EMBRYONIC εy-GLOBIN GENES

Objective. To examine the effect of isobutyramide synthesized in our laboratory on human and murine globin gene expression and to test cell toxicity ofthe drug.Methods. MEL cells were transfected with the recombinant construct μLCRAγψβδβand the stable transformants were cultured in the medium with different concentrations of isobutyramide. The experimental mice and rabbit were injected with different doses of isobutyramide. The globin mRNAs were analyzed by RNase protection assay. The hematological toxicity and electrolyte toxicity ofthe drug were tested.Results. An inducible and dose dependent expression of the human γ , β and mouse α globin gene was observed in the transfected MEL cells. The induction of the human γ globin gene is significant stronger than that of the β globin gene. With 2.5～5 mmol/L isobutyramide, the induction of the human γ globin gene is even more effective than that of mouse α globin gene. After a 15 day injection under the doses of 500～900mg·kg-1·d-1, the level of the mouse embryonic εy globin mRNA could be significantly induced up to 3～4 fold of that of uninjected controls. The changes of hemoglobin(Hb), RBC, hematocrit(HCT), WBC, derived from mice injected with different doses of isobutyramide at the interval of 24 hours for 2～4 weeks, were generally within the normal range. In rabbits injected with isobutyramide in the same regiment for 2 weeks, the concentration of blood K+, Na+, Cl-and CO2 were all within normal range and serum ionic osmotic pressure remained stable as well. Conclusion. Our results suggested that isobutyramide is a weak inducer ofcell differentiation, but it can selectively activate transcription of human γ globin gene at a certain degree, and it can act on early stages of erythroid progenitor differentiation in adult mice and activate transcription of embryonic εy-globin gene and have no hematological toxicity. Our results have further proved the potential value of isobutyramide in treatment of β-thalassemia and sickle cell disease.

Generation and expression analysis of BAC humanized mice carrying HLA-DP401 haplotype

Background:Human leukocyte antigen(HLA)-DP is much less studied than other HLA class Ⅱ antigens,that is,HLA-DR and HLA-DQ,etc.However,the accumulating data have suggested the important roles of DP-restricted responses in the context of cancer,allergy,and infectious disease.Lack of animal models expressing these genes as authentic cis-haplotypes blocks our understanding for the role of HLA-DP haplotypes in immunity.Methods:To explore the potential cis-acting control elements involved in the tran-scriptional regulation of the HLA-DPA1/DPB1 gene,we performed the expression analysis using bacterial artificial chromosome(BAC)-based transgenic humanized mice in the C57BL/6 background,which carried the entire HLA-DP401 gene locus.We further developed a mouse model of Staphylococcus aureus pneumonia in HLA-DP401 humanized transgenic mice,and performed the analysis on the expres-sion pattern of HLA-DP401 and immunological responses in the model.Results:In this study,we screened and identified a BAC clone spanning the entire HLA-DP gene locus.DNA from this clone was analyzed for integrity by pulsed-field gel electrophoresis and then microinjected into fertilized mouse oocytes to produce transgenic founder animals.Nine sets of PCR primers for regional markers with an average distance of 15 kb between each primer were used to confirm the integrity of the transgene in the five transgenic lines carrying the HLA-DPA1/DPB1 gene.Transgene copy numbers were determined by real-time PCR analysis.HLA-DP401 gene expression was analyzed at the mRNA and protein level.Although infection with S aureus Newman did not alter the percentage of immune cells in the spleen and thymus from the HLA-DP401-H2-Aβ1 humanized mice.Increased expression of HLA-DP401 was observed in the thymus of the humanized mice infected by S aureus.Conclusions:We generated several BAC transgenic mice,and analyzed the expres-sion of HLA-DPA1/DPB1 in those mice.A model of S aureus-induced pneumonia in the HLA-DP401-H2-Aβ1^(-/-)humanized mice was further developed,and S aureus in-fection upregulated the HLA-DP401 expression in thymus of those humanized mice.These findings demonstrate the potential of those HLA-DPA1/DPB1 transgenic humanized mice for developing animal models of infectious diseases and MHC-associated immunological diseases.

Down syndrome and the molecular pathogenesis resulting from trisomy of human chromosome 21

Elizabeth Fisher and Victor collaboratively for many years on Tybulewicz have worked the Down syndrome mouse model project. Elizabeth Fisher＇s background is in molecular genetics and mouse models, with an interest in anueploidy. Victor Tybulewicz is an immunologist whose primary interest is in signal transduction from the antigen receptors of B and T cells.

The YAC Contig Construction for Human X Chromosome Xp21. 3—11. 3

The YAC contig construction has been done for the Human X chromosome short armXp21.3—p11.3, a region which contains several genetic disease gene loci and is of highlybiomedical importance. Using known probes(OTC, DXS166, DMDcDNA) and STS markersof this region, YAC screenings are performed by both YAC colony in situ hybridization andPCR methods. Totally 55 YACs are obtained from the YAC libraries of CEPH, ICRF andthe Institute. The size determination, the analysis of 26 pairs of microsatelite STS, the single copy probe hybridization and the Alu-PCR fingerprinting are performed for these YACs.The mapping of these YACs is performed, and finally, 6 YAC contigs in Xp21.3—11.3 are obtained, covering about 15 Mb. This work will greatly facilitate the positional cloning of disease genes or the genome sequencing in this important region.

Human chromosome pellicle antibody recognizing centromere protein-C(CENP-C),the main component of the kinetochore

Recently the antichromosome antisera from several scleroderma patients have been found to recognize the pellicle of metaphase and anaphase chromosomes. In order to identify the pellicle components, we used these antichromosome antisera to screen a human embryonic cDNA library. The sequences of the positive clones are identical to the cDNA gene sequence of CENP-C (centromere protein C), a human centromere autoantigen. This result suggusts that CENP-C is a component of the pellicle of human metaphase and anaphase chromosomes.

Ghosts in the shell:identification of microglia in the human central nervous system by P2Y12 receptor

Microglia are the tissue resident macrophages of the brain and represent the sole immune population located in the parenchyma of the central nervous system （CNS）. These cells are hidden be-tween neurons, astrocytes as well as oligodendrocytes and account for only 5-10% of CNS cells. Even though microglia were already identified in 1913 by the Spanish neuroanatomist Ramon y Cajal and further seminally investigated by his student Pio del Rio Hortega,

Natural Selection on Human Y Chromosomes

In the field of anthropology, the uniparerttally inherited Y chromosome has long been used to trace the paternal lineage of the populations and to understand differences in migration and population genetics between males and females, with additional advantages of small effective population size, suf- ficient markers, and population-specific haplotype distribution （Jobling and Tyler-Smith, 1995; Jin and Su, 2000; Underhill et al., 2000）. Many such population studies have rested on the assumption that all the Y chromosome markers in the non- recombination regions are selectively neutral （Jobling and Tyler-Smith, 2003）.

MODULATION OF THE FREQUENCY OF HUMANCYTOMEGALOViRUS-INDUCED CHROMOSOMEABERRATIONS BY CAMPTOTHECIN

The effects of selected DNA repair inhibitors on the frequency of human cytomegalovirus (HCMV)-induced chromosome aberrations in human peripheral blood lymphocytes (PBLs) were evaluated. Trealment of HCMV-infected PBLs with camptothecin (0.05 to 0.3μg/ml), an inhibitor of topoisomerase I, for 30 hr resulted in a significant (P<0.01) synergistic enhancement of the frequency of HCMV-induced chromosome damage, on the other hand, a significant increase in the frequency of chromosome damage was not noted for infected PBLs treated with either 3-aminobenzamide (3-AB) (3 to 30μg/ml), an inhibitor of poly (ADP-ribose) poiymerase, ur novobiocin 3 to 30 |ig/ml) an inhibitor of topoiso-merase I or excision repair processes for 30 hr. chromatid-type breaks including chromosome exchanges were the predominant type of chromosome aberrations observed in the HCMV-infected cells treated with camptothecin suggesting that HCMV infection is associated with the induction of single-strand DNA breaks. Furthermore, these findings suggest that HCMV infection does rol inflict dircc: DNA damage which is repaired through 3-AB- or novobiocinsensitive pathways.Human cytomegalovirus (HCMV) is a common pathogen which irferfs about 80% of the world's population causing, for the most part, persistent subcliniclil infeclions (Wellcr, 1971). A relatively small percentage of otherwise healthy immunologically competent people experience clinical HCMV disease (Cohen et al., 1985). Generalized HCMV infection, however, is the bane of individuals whose immune system is compromised (Schooley, 1990) Rubin, 1990). Molecular epidemiological studies strongly suggest that HCMV is one of the most frequent cause of congenital infections and that these infections result in a high incidence of birth defects and developmental abnormalities (Alford et al., 1990). Several studies (Nachtigal et al., 1978; Luleci et al., 1980; AbuBakar et al., 1988) have shown that HCMV infectior can result in an increase in the frequency of chromosome aberrations. Since the ability to cause chromosome damage may be significant in the induction of birth defects and possibly in HCMV-induced malignancy, we undertook the present investigation to evaluate the mechanisms by which HCMV may cause chromosome damage. In ths study, the effects of selected DNA repair inhibitors on the frequency of HCMV-induced chromosome aberrations were evaluated. The results indicae that the presence of camptothecin, but nut 3-aminobenzamidc (3-AB) ro novobiocin, results in a concentration-dependent increase in the frequent) of chromosome aberrations in HCMV-infected peripheral blood lymphocytes (PBLs). Accordingly, it is proposed that HCMV-induced chromosome damage in PBLs does not substantially involve DNA repair activities sensitive to inhibition of poly ADP-ribosylation or excision repair processes, but is related to camp of thccin-sersitive DNA repair, conceivably involving the activity of topoisomrrasc I .

Lack of evidence for leukocyte maternal microchimerism in primary biliary cirrhosis

AIM:It is reasonable to assume that microchimerism could also be involved in the induction of primary biliary cirrhosis (PBC).However,previous reports investigated only fetus-microchimerism in women patients.Maternal microchimerism has not been investigated until now. The current study aimed to clear either maternal microchimerism was involved in the pathogenesis of PBC or not. METHODS:We used fluorescence in situ hybridization on paraffin-embedded tissue (We called“Tissue-FiSH”.) to determine whether maternal cells infiltrated in male patients who were diagnosed as having PBC.Tissue-FiSH was performed by using both X and Y specific probes on the biopsy liver sample of 3 male PBC patients. RESULTS:Infiltrating lymphocytes demonstrated both X and Y signals in all 3 male patients. CONCLUSION:Maternal microchimerism dose not play a significant role in PBC.PBC may not relate to fetus and maternal microchimerism.