Cloning of the human homolog of conductin (AXIN2), a gene mapping to chromosome 17q23-q24

Conductin or Axil, an Axin homolog, plays an important role in the regulation of beta-catenin stability in the Wnt signaling pathway. To facilitate the molecular analysis of the human gene, we isolated the human homolog, AXIN2. The cDNA contains a 2529-bp open reading frame and encodes a putative protein of 843 amino acids. Compared with rat and mouse homologs, AXIN2 shows an overall 89% amino acid identity. Several functional domains in this protein are highly conserved including the GRS (95.9%), GSK-3beta (96.3%), Dsh (98%), and beta-catenin (89.9%) domains. Radiation hybrid mapping localized the AXIN2 gene to human chromosome 17q23-q24, a region that shows frequent loss of heterozygosity in breast cancer, neuroblastoma, and other tumors. Human AXIN2 is thus a very strong candidate involved in multiple tumor types.

Gene therapy of viral hepatitis and hepatocellular carcinoma

Gene therapy represents an attractive approach to treat a great variety of diseases, both inherited and acquired, and it is moving slowly from a proof-of-principle phase to a wide application in most medical fields. Liver cancer and viral hepatitis are natural targets for this new therapeutic alternative due to the lack of success of conventional antitumoral and antiviral treatments and the ominous prognosis related with liver tumours. Gene therapy for viral hepatitis is aimed to boost the patient immune response against viral antigens or to make cells resistant to infection by blocking the viral life cycle. Gene transfer techniques applied to the treatment of hepatocellular carcinoma include drug sensitization by suicide genes, genetic immunotherapy, normal tissue protection by transfer of the multidrug resistance gene, replacement of tumour suppressor genes, inhibition of oncogenes and modifications of the biology of the tumour (antiangiogenesis). However, major advances in our understanding of the regulation of gene expression, design of the expression cassettes and development of more efficient gene transfer vectors are mandatory before gene therapy can become a widely used therapeutic modality.

Antitumor effect of allogenic fibroblasts engineered to express Fas ligand (FasL)

Fas ligand is a type II transmembrane protein which can induce apoptosis in Fas-expressing cells. Recent reports indicate that expression of FasL in transplanted cells may cause graft rejection and, on the other hand, tumor cells may lose their tumorigenicity when they are engineered to express FasL. These effects could be related to recruitment of neutrophils by FasL with activation of their cytotoxic machinery. In this study we investigated the antitumor effect of allogenic fibroblasts engineered to express FasL. Fibroblasts engineered to express FasL (PA317/FasL) did not exert toxic effects on transformed liver cell line (BNL) or colon cancer cell line (CT26) in vitro, but they could abrogate their tumorigenicity in vivo. Histological examination of the site of implantation of BNL cells mixed with PA317/FasL revealed massive infiltration of polymorphonuclear neutrophils and mononuclear cells. A specific immune protective effect was observed in animals primed with a mixture of BNL or CT26 and PA317/FasL cells. Rechallenge with tumor cells 14 or 100 days after priming resulted in protection of 100 or 50% of animals, respectively. This protective effect was due to CD8+ cells since depletion of CD8+ led to tumor formation. In addition, treatment of pre-established BNL tumors with a subcutaneous injection of BNL and PA317/FasL cell mixture at a distant site caused significant inhibition of tumor growth. These data demonstrate that allogenic cells engineered with FasL are able to abolish tumor growth and induce specific protective immunity when they are mixed with neoplastic cells.

Loss of imprinting and allele switching of p73 in renal cell carcinoma

p73, a protein that has substantial structural and functional similarity to p53, has recently been identified. It was found to be monoallelically expressed in all cell lines and normal individuals tested. To elucidate its role in cancer development and as a potential imprinted tumor suppressor, we investigated the allele-specific expression of the human p73 gene in 28 cases of renal cell carcinoma and its imprinting status in fetal pancreatic and thymic tissues. Of 12 informative pairs of renal cell carcinoma and matched normal tissues identified by StyI restriction fragment length polymorphism (RFLP) in exon 2, p73 showed monoallelic expression in 11 out of 12 normal tissues but biallelic expression in 8/12 and switched allele expression in 2/12 of the matched corresponding cancers. An imprinting study of the p73 gene in two families using a newly identified exonic BanI RFLP indicated that expression of p73 was limited to the maternal allele in RNA from fetal pancreas and thymus, demonstrating that p73 is imprinted in at least these two tissues. These findings strongly suggest that loss of imprinting or switching of allelic expression of the p73 gene is associated with the development of renal cell carcinoma.

Conserved mode of peptidomimetic inhibition and substrate recognition of human cytomegalovirus protease

Human cytomegalovirus (HCMV) protease belongs to a new class of serine proteases, with a unique polypeptide backbone fold. The crystal structure of the protease in complex with a peptidomimetic inhibitor (based on the natural substrates and covering the P4 to P1' positions) has been determined at 2.7 A resolution. The inhibitor is bound in an extended conformation, forming an anti-parallel beta-sheet with the protease. The P3 and P1 side chains are less accessible to solvent, whereas the P4 and P2 side chains are more exposed. The inhibitor binding mode shows significant similarity to those observed for peptidomimetic inhibitors or substrates of other classes of serine proteases (chymotrypsin and subtilisin). HCMV protease therefore represents example of convergent evolution. In addition, large conformational differences relative to the structure of the free enzyme are observed, which may be important for inhibitor binding.

Genomic organization and mutation analysis of p73 in oligodendrogliomas with chromosome 1 p-arm deletions

p73, a protein having substantial structural and functional similarity to p53, has recently been identified and demonstrated to be a potential tumor suppressor. Its location on human chromosome 1p36.33 implicates p73 as a candidate for neuroblastoma. Like neuroblastoma, oligodendrogliomas also show a high frequency of deletions in chromosome 1p36.3. To determine whether p73 is a potential tumor suppressor gene involved in the development of oligodendrogliomas, we performed mutation analysis of p73 in oligodendrogliomas with chromosome 1 p-arm deletions. We first determined the genomic organization and the intron-exon boundary sequences of the p73 gene by long PCR, vectorette PCR, and Southern hybridization. This gene spans about 65 kb with a large first intron. Primer pairs for the amplification of each of the 13 p73 encoding exons were designed in corresponding introns. The amplicons were then analyzed using the denaturing high-performance liquid chromatography system for mutations in the p73 gene. Twenty oligodendroglioma samples with 1p36.3 deletions were screened, but no mutations were detected except for several polymorphisms. It is thus clear that p73 is not a candidate gene for oligodendroglioma despite its location in the frequently deleted 1p36.3 region.

Gene therapy of liver tumors: principles and applications

The introduction in the last two decades of molecular biology techniques into medical research has produced an explosion in our understanding of the human genetics at the molecular level. It has also contributed to increase our knowledge of the pathophysiology of diseases and opened up new therapeutic possibilities such as the emergence of gene therapy.

Effects of beta-amyloid peptide on transient outward potassium current of acutely dissociated hippocampal neurons in CA1 sector in rats

OBJECTIVE

To explore the mechanism of beta-amyloid peptide (beta-AP) in Alzheimer's disease at ionic channel level.

METHODS

Hippocampal CA1 neurons of 7-21 days' rats were acutely dissociated and the effects of beta-AP on transient outward potassium current were observed by a whole-cell recording patch clamp technique.

RESULTS

beta-AP can significantly block transient potassium current in dose-dependent, time-dependent and partly voltage-dependent manners.

CONCLUSION

beta-AP may decrease the membrane conductance of K+ channels in hippocampal neurons, playing an important role in the pathophysiological mechanism of Alzheimer's disease.

Activation of p73 silent allele in lung cancer

p73, a first p53 relative, has recently been identified and demonstrated to be monoallelically expressed. This protein shows significant amino acid sequence and functional similarities to p53. However, it is unclear whether this protein functions as a tumor suppressor. To elucidate the role of p73 in tumor development, we investigated the expression of the p73 gene in lung cancer. In a comparison between normal lung and tumor tissues, p73 was more highly expressed in tumors. Moreover, using a C/T polymorphism in exon 2 for allele-specific expression analysis in 21 pairs of lung tumors and matched normal tissues, we found that five heterozygous samples exclusively expressed both alleles in tumors while showing monoallelic expression in matched normal tissues. This result was confirmed by single-nucleotide primer extension analysis. Mutation analysis of all 13 coding exons of the gene in 21 lung tumor DNAs revealed several polymorphisms, but no tumor-specific mutations were detected. These findings strongly suggest that p73 may play an important role in lung tumorigenesis through activation of a silent allele and overexpression of wild-type p73 rather than as a tumor suppressor.

In-vitro maturation of human germinal vesicle stage oocytes: role of cumulus cells and epidermal growth factor in the culture medium

In-vitro maturation (IVM) of oocytes is a promising technique to reduce the costs and avert the side-effects of gonadotrophin stimulation for in-vitro fertilization (IVF). The pregnancy rates from oocytes matured in vitro are much lower than those of in-vivo stimulation cycles indicating that optimization of IVM remains a challenge. Therefore, we investigated the effect of supplementation of the medium with gonadotrophins, oestradiol and epidermal growth factor (EGF) and the effect of retaining or removing the cumulus cells on nuclear and cytoplasmic maturation of immature oocytes. Human germinal vesicle (GV) oocytes obtained after gonadotrophin stimulation for intracytoplasmic sperm injection (ICSI) were cultured in a complex defined medium either supplemented with gonadotrophins, oestradiol and physiological concentrations of EGF (2 ng/ml) or gonadotrophins and oestradiol alone. The cumulus cells were either removed or kept intact. In GV stage oocytes cultured without cumulus (group I) significantly more oocytes reached the metaphase II (MII) stage at 30 h in media supplemented with EGF (64.3 versus 33.9%, P < 0.003). For oocytes cultured with intact cumulus (group II), more oocytes reached MII at 30 h than in group I, but there was no difference in medium with or without EGF supplementation (81.8 and 79.8% respectively). Cytoplasmic maturation of MII oocytes was judged from their capability to activate and fertilize after ICSI. In group I, the rates of activation and normal fertilization were similar. However, in group II, significantly more oocytes underwent normal fertilization in the EGF-supplemented than the unsupplemented group (71.7 versus 45.6%, P < 0.05). The cleavage rates of the fertilized oocytes were similar in the sibling oocyte subgroups cultured with or without EGF supplementation, but the overall cleavage rates were higher in cumulus-intact compared to cumulus-denuded oocytes (88.9 versus 47.8%, P < 0.001). Thus, supplementation of the maturation medium with EGF and maintenance of the cumulus during culture improve the nuclear and cytoplasmic maturation of human oocytes in vitro.

(+/-)-trans-2-[3-methoxy-4-(4-chlorophenylthioethoxy)-5-(N-methyl-N- hydroxyureidyl)methylphenyl]-5-(3,4, 5-trimethoxyphenyl)tetrahydrofuran (CMI-392), a potent dual 5-lipoxygenase inhibitor and platelet-activating factor receptor antagonist

By incorporating an N-hydroxyurea functionality onto diaryltetrahydrofurans, a novel series of compounds was investigated as dual 5-lipoxygenese (5-LO) inhibitor and platelet-activating factor (PAF) receptor antagonist. These dual functional compounds were evaluated in vitro for 5-LO inhibition in RBL cell extracts and human whole blood, and PAF receptor antagonism in a receptor binding assay. PAF-induced hemoconcentration and arachidonic acid- and TPA-induced ear edema in mice were used to determine in vivo activities. The structure-activity relationship analysis to define a preclinical lead is presented. (+/-)-trans-2-[3-methoxy-4-(4-chlorophenylthioethoxy)-5-(N-methyl- N-h ydroxyureidyl)methylphenyl]-5-(3,4, 5-trimethoxyphenyl)tetrahydrofuran (40, CMI-392) was selected for further study. In the arachidonic acid-induced mouse ear edema model, 40 was more potent than either zileuton (a 5-LO inhibitor) or BN 50739 (a PAF receptor antagonist), and it demonstrated the same inhibitory effect as a physical combination of the latter two agents. These results suggest that a single compound which both inhibits leukotriene synthesis and blocks PAF receptor binding may provide therapeutic advantages over single-acting agents. The clinical development of compound 40 is in progress.

[Preliminary study on the correlation between neovasculature and metastatic nasopharyngeal carcinoma by computer image analysis]

OBJECTIVE

To investigate the significance of neoangiogenesis in metastasis of nasopharyngeal carcinoma (NPC) so as to clarify further the role of neovascularity in evaluating the prognosis of NPC and the probability of antiangiogenesis in preventing distant metastasis of NPC.

METHODS

Fifty-two patients with metastatic NPC were selected and strictly matched in sex, age, T stage, and N stage with another 52 patients with non-metastatic NPC and survived a long time. The tumor tissues of all 104 patients were retrived for computer-assisted, immunohistochemical analysis of tumor vasculature.

RESULTS

Counts of microvessel and relative area of all microvessels per image were significantly higher in metastatic NPCs than those of curable, non-metastatic NPCs; while average area of microvessel and average perimeter of microvessel in metastatic NPCs were smaller than those of the opposite. No significant difference in any microvessel parameter had been found among various types of metastasis.

CONCLUSIONS

The alterations of microvessel parameters bore significant relationships with metastases of NPC. Evaluation of neovascularity with computer image analysis may help in estimating the prognosis of NPC and in finding out the indications for aggressive multimodal treatments. Angiogenesis inhibitors might be helpful in preventing NPC from distant metastasis.

Fish mapping of YAC clones at human chromosomal band 7q31.2: identification of YACS spanning FRA7G within the common region of LOH in breast and prostate cancer

Loss of DNA sequences within human chromosomal band 7q31.2 is frequently observed in a number of different solid tumors including breast, prostate, and ovarian cancer. This chromosomal band also contains the common fragile site, FRA7G. Many of the common fragile sites occur within chromosomal regions that are frequently deleted during tumor formation but their precise position, relative to the chromosome breakpoints and deletions, has not been defined for the majority of the fragile sites. Because the frequency of expression of FRA7G is low, we analyzed the expression of FRA7G in a chromosome 7-only somatic cell hybrid (hamster-human). YAC clones defining a contig spanning 7q31.2 were then used as FISH probes against metaphase spreads prepared from the hybrid cells after aphidicolin induction. This analysis quickly revealed whether a specific YAC clone mapped proximal, distal, or actually spanned the region of decondensation/breakage of FRA7G. By using this approach, we have identified several overlapping YAC clones that clearly span FRA7G. Interestingly, these clones map precisely to the common region of LOH in breast cancer and prostate cancer. In addition, the MET oncogene is contained within the three YACs that span FRA7G.

Sperm-associated oocyte-activating factor is released from the spermatozoon within 30 minutes after injection as a result of the sperm-oocyte interaction

We have previously shown that sperm plasma membrane damage makes the sperm plasma membrane permeable and the sperm nucleus accessible for low molecular weight molecules such as eosin and dithiothreitol. In the present study, we investigated whether this damage is associated with a passive release of the sperm-associated oocyte activating factor (SAOAF) from the spermatozoon and, if so, its time sequence. In a first study, human oocytes remaining unfertilized after conventional in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) and freshly ovulated mouse oocytes were injected with a whole spermatozoon or a sperm head respectively. They were randomly allocated to one of three groups: oocytes in group 1 were injected with a spermatozoon immobilized or sperm head detached immediately prior to the injection; oocytes in group 2 were injected with a spermatozoon immobilized or sperm head detached 2-4 h before injection; oocytes in group 3 were injected with a spermatozoon or sperm head that had been subjected to heat treatment. The activation rate of oocytes injected with a spermatozoon or sperm head was the same for groups 1 and 2, and significantly higher than in group 3 (P < 0.001). In a second series of experiments, human oocytes remaining unfertilized after IVF or ICSI were injected with a sperm head that was subsequently removed from the ooplasm 20-30 min after injection. The activation rates were compared to that of oocytes injected with heat-treated spermatozoa which subsequently were removed from the ooplasm. We found that the removal of the spermatozoon 30 min after injection did not prevent oocyte activation. Our data indicate that the initial damage to the sperm plasma membrane induced at immobilization, although essential for the onset of sperm nuclear swelling after ICSI, does not by itself lead to the release of SAOAF from the spermatozoon. We postulate, however, that SAOAF is released during the sperm nuclear swelling phase, which is induced by the so-called sperm nucleus decondensing factor (SNDF) of the oocyte.

The gene for microfibril-associated protein-1 (MFAP1) is located several megabases centromeric to FBN1 and is not mutated in Marfan syndrome

Linkage studies have mapped the Marfan syndrome (MFS) locus to chromosome region 15q15-q21 with no convincing evidence of genetic heterogeneity. The fibrillin-1 (FBN1) gene, located at 15q21.1, that encodes the major component of the defective microfibrils, has been identified as the gene for MFS. However, extensive mutation screening in many laboratories has detected FBN1 mutations in only a fraction of MFS probands studied, leading to the hypothesis that the missing mutations could involve another microfibril gene located in the same region. Recently, the gene for microfibril-associated protein-1 (MFAP1, also called AMP) has been isolated and mapped to the 15q15-q21 region that overlaps the location of the FBN1 gene. Here we report that the two loci are physically close, making MFAP1 an alternative positional candidate gene for MFS. We have carried out MFAP1 mutation screening and gene expression analysis in 48 probands with MFS or related phenotypes who were selected for this study because their fibroblast cultures synthesized fibrillin at normal levels. No MFAP1 mutations were identified, and transcription occurred equally from both alleles. We conclude that the MFAP1 locus is not a reservoir for the hidden MFS mutations.

Gene transfer and therapy with adenoviral vector in rats with diethylnitrosamine-induced hepatocellular carcinoma

In rats with diethylnitrosamine (DENA)-induced hepatocellular carcinoma (HCC), we studied in vivo gene transfer efficiency using intraportal injections of recombinant adenovirus carrying the lacZ reporter gene (AdCMVlacZ) and the therapeutic efficacy of adenovirus-mediated transfer of the thymidine kinase gene of the herpes simplex virus (HSV-tk) followed by ganciclovir (GCV) administration. DENA was very effective in inducing HCC but also stimulated nontumor cell replication, as shown by proliferating cell nuclear antigen (PCNA) staining. The study of in vivo gene transfer efficiency in tumor-bearing rats showed that nontumor tissue and small tumor nodules were transduced effectively whereas a poor transduction rate was noted in large tumor nodules. Concerning therapeutic efficacy, three groups of rats with established HCC were studied: group A and B received intraportally recombinant adenovirus carrying HSV-tk (AdCMVtk) or AdCMVlacZ, respectively, and 2 days after GCV was given intraperitoneally for 9 days; group C received only saline. Of the rats from groups B and C, 100% and 93% respectively, exhibited multiple HCC tumor nodules at end of the study. In contrast, a complete regression of tumor was observed in 63% of animals from group A. This group showed significant elevation of serum transaminases and a diffuse hepatotoxic lesion in liver tissue; histological signs of regeneration were observed in surviving animals. Nine out of 19 rats from group A died during the treatment period. We conclude that (i) in the DENA model of HCC, tumoral cells can be destroyed in vivo by the HSV-tk/GCV system despite poor transduction of large tumor nodules, suggesting that toxic metabolites generated by nontumor cells may exert a bystander effect on tumor tissue; (ii) significant hepatoxicity and a high mortality rate occurred in HSV-tk/GCV-treated rats; these side effects appear to be due to the fact that in DENA-treated livers enhanced cell proliferation was present not only in tumor nodules but also in nontumor parenchyma, leading to GCV sensitization of both tissues; (iii) our results have implications concerning the efficacy and potential risks of the HSV-tk/GCV system in the treatment of human HCC.

A phase I/II study of external beam radiation, brachytherapy and concurrent chemotherapy in localized cancer of the esophagus (RTOG 92-07): preliminary toxicity report

PURPOSE

A multi-institutional, prospective study was designed to determine the feasibility and tolerance of external beam irradiation plus concurrent chemotherapy and esophageal brachytherapy (EB) in a potentially curable group of patients with adenocarcinoma or squamous cell carcinoma of the esophagus.

METHODS AND MATERIALS

Planned treatment was 50 Gy external beam radiation (25 fractions/5 weeks) followed 2 weeks later by EB [either high dose rate (HDR) 5 Gy, weeks 8, 9, and 10, for a total of 15 Gy, or low dose rate (LDR) 20 Gy, week 8]. The protocol was later revised to delete the LDR alternative, owing to poor accrual, and to decrease the HDR dose to 10 Gy (i.e. 5 Gy, weeks 8 and 9). Chemotherapy was given weeks 1, 5, 8, and 11 with cisplatin 75 mg/m2 and 5-fluorouracil 1000 mg2/m per 24 h, 96-h infusion. The study closed in January 1995 after 56 patients had been entered on the HDR arm. Six patients were declared ineligible owing to tumor extension to the gastroesophageal junction (three patients) or involved celiac lymph nodes (three patients). Of the 50 eligible patients, the planned EB dose was 15 and 10 Gy in 40 and 10 patients, respectively. Forty-six (92%) of the eligible patients had squamous histology, and three (6%) adenocarcinoma.

RESULTS

Life-threatening toxicity or treatment-related death occurred in 13 (26%) and 4 (8%) of the 50 eligible patients, respectively. Treatment-related esophageal fistulas occurred in three patients (12% overall, 14% of patients starting EB) at 0.5-6.2 months from the first day of brachytherapy, leading to death in three. The fourth death was secondary to renal toxicity and infection attributed to chemotherapy. No correlation was found between the development of fistula and location of primary tumor, brachytherapy active length or applicator diameter. So far, 5 of the 6 treatment-related fistulas have occurred following 15 Gy EB. The other fistula occurred after only 5 Gy of a planned 15 Gy was delivered.

CONCLUSION

Thirty-five patients (70%) were able to complete external beam, EB, and at least two courses of chemotherapy. Estimated survival rate at 12 months is 48%, with an estimated 11-month median survival rate. Survival following external beam radiation plus concurrent chemotherapy and EB does not appear to be significantly different from survival seen following external beam radiation and chemotherapy only. The development of six fistulas in the 35 patients completing EB is of concern. Based on the high incidence of fistulas, we urge extreme caution in employing EB as a boost following concurrent external beam radiation and chemotherapy.

Mutant fibrillin-1 monomers lacking EGF-like domains disrupt microfibril assembly and cause severe marfan syndrome

Marfan syndrome (MFS), a heritable connective tissue disorder, is caused by mutations in the gene coding for fibrillin-1 (FBN1), an extracellular matrix protein. One of the three major categories of FBN1 mutations involves exon-skipping. To rapidly detect such mutations, we developed a long RT-PCR method. Either three segments covering the entire FBN1 coding sequence or a single 8.9 kb FBN1 coding segment were amplified from reverse-transcribed total fibroblast RNA. Restriction fragment patterns of these RT-PCR products were compared and abnormal fragments were directly sequenced. Six exon-skipping mutations were identified in a panel of 60 MFS probands. All skipped exons encode calcium binding epidermal growth factor (EGF)-like domains and maintain the reading frame. In five probands, exon-skipping was due to point mutations in splice site sequences, and one had a 6 bp deletion in a donor splice site. Pulse-chase analysis of labelled fibrillin protein revealed normal levels of synthesis but significantly reduced matrix deposition. This dominant-negative effect of the mutant monomers is considered in the light of current models of fibrillin assembly. Probands with this type of FBN1 mutation include the most severe forms of MFS, such as neonatally lethal presentations.

A new serine-protease fold revealed by the crystal structure of human cytomegalovirus protease

Human cytomegalovirus (hCMV), a herpesvirus, infects up to 70% of the general population in the United States and can cause morbidity and mortality in immunosuppressed individuals (organ-transplant recipients and AIDS patients) and congenitally infected newborns. hCMV protease is essential for the production of mature infectious virions, as it performs proteolytic processing near the carboxy terminus (M-site) of the viral assembly protein precursor. hCMV protease is a serine protease, although it has little homology to other clans of serine proteases. Here we report the crystal structure of hCMV protease at 2.0 angstroms resolution, and show that it possesses a new polypeptide backbone fold. Ser 132 and His 63 are found in close proximity in the active site, confirming earlier biochemical and mutagenesis studies. The structure suggests that the third member of the triad is probably His 157. A dimer of the protease with an extensive interface is found in the crystal structure. This structure information will help in the design and optimization of inhibitors against herpesvirus proteases.

Determination of avermectin B1 in biological samples by immunoaffinity column cleanup and liquid chromatography with UV detection

A simple and specific procedure for determination of avermectin B1 in biological samples is described. A specific anti-avermectin B1 immunosorbent was developed. Avermectin B1 was extracted from cattle plasma, cattle meat, and pear samples. The extracts were cleaned up on a solid-phase extraction column (C18) and an immunoaffinity column. Avermectin B1 was determined by reversed-phase liquid chromatography with UV detection at 245 nm. Recoveries of avermectin B1 from samples spiked at levels of 6 and 60 parts per billion (ppb) ranged from 80 to 86%, with coefficients of variation of 5-14%. The limit of detection was 2 ppb. The procedure provides a simple and sensitive method for monitoring avermectin B1 residues in biological matrixes.

Oocyte morphology does not correlate with fertilization rate and embryo quality after intracytoplasmic sperm injection

The fertilization rates and further development of 528 human metaphase II oocytes directly injected by a single spermatozoon were analysed with respect to their morphological features at the light microscopy level at the time of retrieval. The deviations of oocyte morphology which were most frequently observed, after removal of cumulus cells, were dark incorporations, dark zona pellucida, large perivitelline space, spots, vacuoles, refractile bodies and irregular shape. These deviations correlated neither with the fertilization rate nor with the embryo quality score, as compared to 'ideal' oocytes. Since the majority of oocytes displayed deviations from the 'ideal' morphotype but were still fertilized and developed in culture at a normal rate, they were probably as normal as 'ideal' oocytes. Since some of these morphotypes, such as refractile bodies, have been shown to be associated with failure of fertilization, it seems that intracytoplasmic sperm injection may be an appropriate method of treatment for couples in whom repeated failure of in-vitro fertilization is associated with the retrieval of dysmorphic oocytes in the presence of normal semen characteristics.

Tumor necrosis factor alpha gene expression and the response to interferon in chronic hepatitis C

Tumor necrosis factor alpha (TNF-alpha) is a cytokine with pleiotropic properties that is induced in a variety of pathological situations including viral infections. In this work, we analyzed the expression of TNF-alpha gene in patients with chronic hepatitis C. Serum TNF-alpha levels were found to be elevated in all chronic hepatitis C patients including those cases presenting sustained biochemical remission of the disease after interferon therapy. Untreated patients with chronic hepatitis C showed increased TNF-alpha messenger RNA (mRNA) levels in the liver and mononuclear cells as compared with healthy controls. After completion of treatment with interferon, patients experiencing sustained complete response showed values of TNF-alpha mRNA, both in the liver and in peripheral mononuclear cells, within the normal range, significantly lower than patients who did not respond to interferon and than those with complete response who relapsed after interferon withdrawal. Pretreatment values of TNF-alpha mRNA were lower in long-term responders to interferon than in cases who failed to respond to the treatment. Values of TNF-alpha mRNA in the liver or in mononuclear cells were higher in specimens with positive hepatitis C virus (HCV) RNA than in those samples where the virus was undetectable. Neither the intensity of the liver damage nor the amount of HCV RNA in serum or in cells showed correlation with the levels of TNF-alpha transcripts in peripheral mononuclear cells but it was found that high TNF-alpha values were associated with genotype 1b. In conclusion, there is an enhanced expression of TNF-alpha in HCV infection. High levels of this cytokine may play a role in the resistance to interferon therapy.

Risk factors for hepatic veno-occlusive disease following HLA-identical sibling bone marrow transplants for leukemia

The objective was to analyze risk factors for veno-occlusive disease of the liver (VOD) after allogeneic bone marrow transplantation. A cohort of 1717 recipients of HLA-identical sibling transplants for leukemia between 1988 and 1990, in 200 transplant teams worldwide, was studied. Patients were scored as having VOD if liver tissue showed typical histologic features or if they had all three of the following: (1) jaundice; (2) hepatomegaly and right upper quadrant abdominal pain; and (3) ascites and/or unexplained weight gain. Patients surviving more than 7 days post-transplant without histologic or any of these clinical features of VOD were classified as not having VOD. Patient-, disease- and transplant-related characteristics of 95 patients with VOD were compared to those of 1514 without VOD. Variables correlated with an increased risk of VOD were: pretransplant conditioning with busulfan and cyclophosphamide compared to total body radiation (relative risk (RR) 2.8; P < 0.0001), pretransplant fungal infection (RR 4.1; P = 0.011), pretransplant Karnofsky performance score < 90% (RR 1.9; P = 0.012), prior liver disease (RR 1.9; P = 0.05) and age > 20 years (RR 1.8; P = 0.05). In patients receiving radiation for conditioning, intravenous immune globulin decreased VOD risk (RR 0.26; P = 0.003). This analysis identifies risk factors for VOD. The data suggest several strategies for modifying transplant regimens to reduce VOD risk and which patients might be suitable subjects for trials of strategies of VOD prevention.

Does assisted hatching improve implantation rates after in vitro fertilization or intracytoplasmic sperm injection in all patients? A prospective randomized study

PURPOSE

Preliminary data from some research centers indicate that assisted hatching might be of value to increase embryo implantation rate in the human, at least in selected cases. It is not clear, however, whether this technique would be of benefit for all patients undergoing an embryo transfer. We therefore performed a prospective randomized study to evaluate the effect of assisted hatching on the implantation rate in our in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) program.

METHODS

In total, 120 couples undergoing an embryo transfer were randomized between two groups: in one group no assisted hatching was performed (AH-), whereas in the other group the embryos selected for transfer were subjected to partial zona dissection (PZD) immediately prior to the transfer (AH+). Using a computer-generated minimization procedure, patients were allocated to one of the two groups according to four pre-selected criteria: the number of embryos transferred, the cumulative score of transferred embryos, the age of the patient, and the use of ICSI.

RESULTS

Pregnancy and implantation rates in the AH+ and AH- groups were, respectively, 42.1 versus 38.1% and 17.9 versus 17.1%.

CONCLUSIONS

From our data we conclude that assisted hatching through partial zona dissection prior to embryo transfer does not improve pregnancy and embryo implantation rates in unselected patients undergoing IVF or ICSI.

Combination drug therapy of seropositive rheumatoid arthritis

OBJECTIVE

To determine the longterm morbidity and mortality in a cohort of 169 patients with seropositive rheumatoid arthritis (RA) treated by a single rheumatologist with remittive agents used in combination. The effectiveness of a regimen combining pulse oral methotrexate, azathioprine and an antimalarial drug (MAH) was examined in detail.

METHODS

All outpatient visits by patients followed for at least one year and up to 18 years (mean 7 years) were abstracted. Remittive antirheumatic drugs were used in combination to achieve progressive improvement. Univariate and multivariate analyses of the differences between first and last visit results in 9 process or outcome variables were calculated for the entire cohort, for those patients receiving or not receiving MAH at last visit, and for those patients taking methotrexate but not in combination with both azathioprine and an antimalarial. The numbers of patients in remission (Lansbury articular index zero), and near remission (articular index < 6) were determined for each of these groups. A survival curve was calculated.

RESULTS

The entire patient cohort showed improvement in every variable except hemoglobin at the time of the last visit (p < 0.0004). On multivariate analysis MAH patients were improved only in American Rheumatism Association functional class compared to the other groups (p < 0.0001). Remission and near remission rates overall were 43 and 61%; for MAH patients 45 and 69% (p = n.s.). Survival was no different from that of the general population. Herpes zoster (17 patients) and second attacks of varicella (2 patients) were the most striking side effects. Prednisone use was reduced from 34 to 19% of patients and the mean daily dose was lowered from 9.3 to 5.9 mg.

CONCLUSION

Combination therapy with multiple antirheumatic agents successfully controlled joint inflammation in 167 of 169 patients with seropositive RA; complete remission was achieved in 43% of patients. Survival of this patient cohort did not differ from that of the general population.

Treatment of rheumatoid joint inflammation with intrasynovial triamcinolone hexacetonide

OBJECTIVE

To determine the effectiveness of intrasynovial triamcinolone hexacetonide coupled with joint rest (3 weeks upper extremity; 6 weeks lower extremity) in the treatment of joint and tendon sheath inflammation in patients with seropositive rheumatoid arthritis (RA).

METHODS

The medical records of 169 patients with seropositive RA treated by a single rheumatologist for at least one year between 1974 and 1992 were abstracted.

RESULTS

Nine hundred fifty-six injections were given to 140 patients; approximately 75% of injected synovial structures remained in remission during a mean followup 7 years; 218 injections were given into previously treated structures. The injection rate was about 2 per patient in the first year, half of which were given at the time of the first visit. The rate then approximated 0.6 injections per patient-year for the next 15 years. Joints in the right upper extremity were injected significantly (p = 0.01) more frequently than those on the left.

CONCLUSION

Intrasynovial triamcinolone hexacetonide followed by rest is a very useful adjunctive modality in the treatment of seropositive rheumatoid arthritis.

Vaccination of sheep against Schistosoma japonicum with either glutathione S-transferase, keyhole limpet haemocyanin or the freeze/thaw schistosomula/BCG vaccine

The protective potential of glutathione S-transferase (GST), keyhole limpet haemocyanin (KLH) and the freeze/thaw (F/T) schistosomula/BCG vaccine was evaluated against Schistosoma japonicum in the natural sheep host. Groups of ten sheep each were vaccinated as follows: Group I: 2 x F/T 30,000 schistosomula+BCG 3 x 10(8) organisms, with a 2 week interval between vaccinations (F/T 'Low'). Group II: 3 x F/T 20,000 schistosomula+BCG 3 x 10(8), with 4 week interval (F/T 'High'). Group III: 2 x GST 0.24 mg+FCA (Freund's complete adjuvant) with 2 week interval (GST 'Low'). Group IV: 3 x GST 0.24 mg+FCA, with 4 week interval (GST 'High'). Group V: 2 x KLH 1.0 mg in phosphate-buffered saline (PBS), with 2 week interval (KLH 'Low'). Group VI: 3 x KLH 1.0 mg in PBS, with 4 week interval (KLH 'High'). Group VII: control (not vaccinated). Specific antibody, detected by GST-enzyme-linked immunosorbent assay (ELISA) and KLH-ELISA on the day after the last vaccination and 1, 2 and 3 weeks post-challenge, was found in all GST- or KLH-vaccinated groups. The same was found in F/T schistosomula-vaccinated groups against crude adult worm antigen (AWA). In Western blotting all GST-vaccinated sera recognized 26 kDa and 28 kDa bands on the challenge day and at 3 and 11 weeks post-challenge. Mean faecal egg counts between Weeks 6 and 10 post-challenge were reduced in a statistically significant way at five time points in the four groups, i.e. 83.38% (P < 0.005) in Group II, 49.29% (P < 0.025) in Group III, 47.9% (P < 0.05) and 71.15% (P < 0.01) in Group IV, 52.0% (P < 0.025) and 66.38% (P < 0.025) in Group VI. On autopsy and perfusion 1 week after the last faecal count, adult worm reductions were obtained of 40.36% (P < 0.05) in Group I, 37.26% (P < 0.025) in Group II, 24.73% (not significant) in Group III, 35.93% (P < 0.025) in Group IV, 27.46% (P < 0.05) in Group V and 33.81% (P < 0.01) in Group VI. Mean tissue egg densities were also reduced significantly in Groups III, IV and VI, especially in Group IV vaccinated animals. Mean liver egg granuloma diameters of the vaccinated groups were found to be less than those of the controls but there was no statistical significance.(ABSTRACT TRUNCATED AT 400 WORDS)

Induction of sensitivity to ganciclovir in human hepatocellular carcinoma cells by adenovirus-mediated gene transfer of herpes simplex virus thymidine kinase

We have analyzed the ability of a recombinant replication-defective adenovirus to transfer the thymidine kinase gene of herpes simplex virus (HSV-tk) into hepatocellular carcinoma (HCC) cells to confer sensitivity to ganciclovir. Three HCC cell lines (Hep3B, PLC/PRF/5, and HepG2) were efficiently infected in vitro by a recombinant adenovirus carrying lacZ reporter gene (AdCMVlacZ). Expression of HSV-tk in HCC cells infected with a recombinant adenovirus carrying HSV-tk gene (AdCMVtk) induced sensitivity to ganciclovir in a dose-dependent manner. A bystander killing effect was observed when 90% of uninfected tumor cells were mixed with only 10% of AdCMVtk-infected cells. These data show that recombinant adenoviruses are efficient vectors for transduction of drug-sensitizing genes to HCC cells in vitro. We suggest that a gene therapy approach to hepatocellular carcinoma can be established using adenoviral transfer of HSV-tk to tumor cells and subsequent administration of ganciclovir.

Taurocholate-stimulated leukotriene C4 biosynthesis and leukotriene C4-stimulated choleresis in isolated rat liver

BACKGROUND/AIMS

Cysteinyl-containing leukotrienes seem to exert a cholestatic effect. However, leukotriene inhibitors were found to reduce bile salt efflux in isolated rat hepatocytes, suggesting a role for leukotrienes in bile flow formation.

METHODS

In the isolated rat liver, the effects of two different concentrations of leukotriene C4 on bile flow and bile salt excretion are analyzed, as well as the possible effect of taurocholate on the hepatic production of cysteinyl-containing leukotrienes.

RESULTS

Leukotriene C4 (0.25 fmol) increased bile salt excretion (+22.2%; P < 0.05), whereas a much higher dose (0.25 x 10(6) fmol) showed the known cholestatic effect, reducing bile salt excretion (-25.9%; P < 0.01). These dose-dependent biphasic effects were specific because they could be prevented by the simultaneous administration of cysteinyl-containing leukotriene antagonists. On the other hand, taurocholate administration induced a dose-dependent increase in biliary excretion of cysteinyl-containing leukotrienes. Furthermore, taurocholate increased messenger RNA levels of 5-lipoxygenase, a key enzyme in leukotriene biosynthesis. Taurocholate increase of hepatocyte intracellular calcium was not significant, suggesting that taurocholate effects are not mediated by stimulation of calcium metabolism.

CONCLUSIONS

These results constitute evidence for the existence of a positive feedback mechanism by which bile salts stimulate the synthesis of leukotrienes that, in turn, stimulate bile salt excretion.

Intracytoplasmic injection of human spermatozoa into mouse oocytes: a useful model to investigate the oocyte-activating capacity and the karyotype of human spermatozoa

When intracytoplasmic sperm injection (ICSI) is performed, it is important to know the capacity of sperm cells to activate the oocytes, although knowledge of their ability to fuse with the oocytes is not vital. Hamster oocytes are not suitable for this purpose because they are easily activated by the injection procedure Itself. We therefore investigated whether mouse oocytes could be used to assess the activation properties of human spermatozoa. Mouse oocytes were randomized for injection with initially motile spermatozoa, medium, heat-treated or salt-extracted spermatozoa, and the survival and activation rates were examined. About half of the mouse oocytes survived the intracytoplasmic injection of a human sperm cell. Unlike hamster oocytes, the rate of activation provoked by the injection procedure itself was acceptably low (20%), resembling in this respect the behaviour of human oocytes. Following the injection of initially motile human spermatozoa, all mouse oocytes were activated. The injection of heat-treated or salt-extracted human spermatozoa resulted in activation rates of 14 and 15% respectively, comparable with the results following sham ICSI. These data support the hypothesis of a sperm-associated oocyte activation factor. In most activated oocytes, the human sperm nucleus decondensed to form a male pronucleus. Cytogenetic analysis at the first metaphase revealed that human sperm chromosomes were able to undergo replication in a heterologous environment.(ABSTRACT TRUNCATED AT 250 WORDS)

Different mechanisms of aralkylation of adenosine at the 1- and N6-positions

The eight products resulting from opening of either enantiomer of styrene oxide at the alpha- or beta-carbon by the 1- or N6-positions of adenosine were prepared and their configurations assigned. These markers allowed the mechanism of aralkylation of adenosine by styrene oxide to be investigated. It was found that formation of alpha-substituted products at the 1-position of adenosine involved total inversion of stereochemistry, whereas at the N6-position inversion: retention was approximately 6:1. These differences in stereochemistry suggest that a more ionic form of styrene oxide is involved in N6-aralkylation than in 1-aralkylation of adenosine. In the course of these studies, it was found that 1-substituted adenosines at the alpha- and beta-carbon of styrene oxide undergo Dimroth rearrangement at neutral pH and 37 degrees C and that the former compound also deaminates fairly readily under these conditions.

Human oocyte activation following intracytoplasmic injection: the role of the sperm cell

The aim of this study was to investigate whether the human spermatozoon participates in the activation of human oocytes following intracytoplasmic sperm injection (ICSI) and if so, by what mechanism. In the first series of experiments, we randomized human oocytes which had remained unfertilized after in-vitro fertilization (IVF) or ICSI, for intracytoplasmic injection with live spermatozoa, spermatozoa presumed to be dead and no spermatozoa. Secondly, unfertilized human oocytes and freshly ovulated mouse oocytes were randomized for intracytoplasmic and sub-zonal injection with human sperm cytosolic fraction (CF) before and after heat treatment. We found that oocyte injection with initially motile spermatozoa induces human oocyte activation at a significantly higher rate than injection with dead spermatozoa (61 versus 0%; P < 0.001) or injection without a spermatozoon (61 versus 14%; P < 0.001). Intracytoplasmic injection of CF activated both human and mouse oocytes at the same rate as sperm injection of human oocytes (activation rates of 70 and 65% respectively). This effect was greatly reduced by heat treatment of the CF. From these experiments we conclude firstly that the human spermatozoon injected intracytoplasmically contributes to human oocyte activation and secondly that the spermatozoon releases into the oocyte a heat-sensitive, intracellularly active factor, which is not species-specific.

Cardiovascular and pulmonary responses to Pichinde virus infection in strain 13 guinea pigs

In fatal human Lassa fever, severe hypotension, circulatory shock, and pulmonary edema develop as terminal events. We examined cardiovascular and respiratory functions in strain 13 guinea pigs infected with Pichinde virus, an animal model for studying human Lassa fever. Cardiovascular functions were studied in anesthetized and conscious guinea pigs, whereas pulmonary functions were measured only on animals under anesthesia. In anesthetized animals, cardiovascular disturbances were severe and progressive from postinoculation day (PID) 10. Cardiac output, measured by thermodilution, decreased 28 to 53% below baseline values from PID 10 to 12 and was accompanied by a gradual reduction of mean arterial blood pressure and heart rate. Although left ventricular systolic pressure decreased significantly, the left ventricular +dp/dtmax and -dp/dtmax decreased only slightly on PID 12. Similar depressed cardiovascular responses were observed in conscious animals infected with Pichinde virus. Changes included decreased cardiac output, heart rate, cardiac work, cardiac power, and stroke volume, as well as increased total peripheral resistance and prolonged mean transit time. We postulate that a global cardiovascular dysfunction with the involvement of right and left sides of the heart may be the main cause of irreversible circulatory deterioration and death during Pichinde virus infection in strain 13 guinea pigs.

Molecular and cytogenetic studies of an X;autosome translocation in a patient with premature ovarian failure and review of the literature

We have identified a patient with premature ovarian failure (POF) and a balanced X;autosome translocation: 46,X,t(X;6)(q13.3 or q21;p12) using high-resolution cytogenetic analysis and FISH. BrdU analysis showed that her normal X was late-replicating and translocated X earlier-replicating which is typical of balanced X;autosome rearrangements. Molecular studies were done to characterize the breakpoint on Xq and to determine the parental origin. PCR probes of tetranucleotide and dinucleotide repeat polymorphisms, and genomic probes were used to study DNA from the patient, her chromosomally normal parents and brother, and somatic cell hybrids containing each translocation chromosome. The translocation is paternally derived and is localized to Xq13.3-proximal Xq21.1, between PGK1 and DXS447 loci, a distance of 0.1 centimorgans. A "critical region" for normal ovarian function has been proposed for Xq13-q26 [Sarto et al., Am J Hum Genet 25:262-270, 1973; Phelan et al., Am J Obstet Gynecol 129:607-613, 1977; Summitt et al., BD:OAS XIV(6C):219-247, 1978] based on cytogenetic and clinical studies of patients with X;autosome translocations. Few cases have had molecular characterization of the breakpoints to further define the region. While translocations in the region may lead to ovarian dysfunction by disrupting normal meiosis or by a position effect, two recent reports of patients with premature ovarian failure and Xq deletions suggest that there is a gene (POF1) localized to Xq21.3-q27 [Krauss et al., N Engl J Med 317:125-131, 1987; Davies et al., Cytogenet Cell Genet 58:853-966, 1991] or within Xq26.1-q27 [Tharapel et al., Am J Hum Genet 52:463-471, 1993] responsible for POF.(ABSTRACT TRUNCATED AT 250 WORDS)

Epibatidine is a nicotinic analgesic

Epibatidine, an alkaloid isolated from skin of the poison frog, Epipedobates tricolor, has been shown to be a very potent analgesic with a non-opioid mechanism of action. We found that epibatidine was about 120 times more potent and has longer duration than nicotine in analgesia, which could be antagonized by pretreatment with mecamylamine. Furthermore, epibatidine competed with high affinity (IC50 = 70 pM, Ki = 43 pM) for [3H]cytisine binding in rat brain preparations. These results indicated that the analgesic activity of epibatidine is attributed to its unique property as the most potent nicotinic acetylcholine receptor agonist.

Changes in platelet-activating factor, catecholamine, and serotonin concentrations in brain, cerebrospinal fluid, and plasma of pichinde virus-infected guinea pigs

Brain concentrations of platelet-activating factor (PAF), catecholamines, and serotonin were measured in control and Pichinde virus-infected strain 13 guinea pigs on postinoculation day (PID) 12. After virus inoculation, PAF concentrations increased 81% in cerebrum, 147% in diencephalon-brain stem, and 110% in cerebellum from baseline values of 2.6 +/- 0.3, 4.3 +/- 0.2, and 6.1 +/- 0.5 (ng/g wet tissue), respectively. Dopamine concentrations in the infected cerebrum and diencephalon-brain stem increased significantly, whereas norepinephrine concentration increased only in cerebrum. However, serotonin concentrations in all three regions of infected brain decreased significantly as compared with control values. There were no significant changes in epinephrine concentrations of infected brain. Norepinephrine and epinephrine concentrations in plasma and cerebrospinal fluid on PID 7 and 12 increased significantly as compared with control values, while plasma dopamine concentration increased significantly on PID 7. Increased brain PAF, dopamine, and and norepinephrine concentrations with decreased brain serotonin concentrations may mediate the hyperactivity of the hypothalamic-pituitary-adrenal axis and involve some unknown pathophysiologic processes of arenaviral infection. Furthermore, increased plasma catecholamine concentrations are associated with stress and may be partially responsible for the development of cardiovascular dysfunction and pulmonary edema during this viral disease.

Hepatic and extrahepatic HCV RNA strands in chronic hepatitis C: different patterns of response to interferon treatment

We investigated the presence of positive (genomic) and negative (replicative intermediate) hepatitis C virus RNA strands in liver, peripheral mononuclear cells and serum from patients with chronic hepatitis C using a selective and semiquantitative polymerase chain reaction procedure. Negative and positive hepatitis C virus RNA strands were present in liver, serum and lymphoid cells in all untreated patients and in all those who did not respond to interferon therapy. In the latter group of patients, the titers of RNA strands in the liver and peripheral mononuclear cells at the end of the treatment were similar to those encountered in untreated patients, but the serum titers were about 100 times lower than pretreatment values. In patients who responded to interferon with normalization of serum aminotransferase levels (n = 10), the rate of detection and the titer of the two viral strands in liver, serum and mononuclear cells were markedly decreased at the end of the therapy. In the six responders who did not relapse after interferon withdrawal, both hepatitis C virus RNA strands were absent from the liver, serum and lymphoid cells. By contrast, the positive RNA strand was present in liver cells, mononuclear cells or both at the end of therapy in all patients who experienced posttherapy relapse. In conclusion, our results indicate that interferon can clear hepatitis C virus from hepatic and extrahepatic sites only in responder patients. Disappearance of genomic hepatitis C virus RNA from the liver and from mononuclear cells may predict complete response without posttherapy relapse.

Abnormal expression of anion exchanger genes in primary biliary cirrhosis

BACKGROUND

Chloride-bicarbonate anion exchangers (AE) are thought to be essential to the generation of ion fluxes into biliary, salivary, pancreatic, and other secretions. In primary biliary cirrhosis (PBC), chronic cholestasis is frequently associated with pluriglandular exocrine failure. The present study examined the expression of AE genes in PBC at the messenger RNA (mRNA) level.

METHODS

Two AE messages, i.e., AE1 and AE2 mRNAs, were analyzed by a polymerase chain reaction-based procedure in liver specimens and peripheral mononuclear cells of patients with PBC and control subjects (with normal livers or with miscellaneous liver diseases).

RESULTS

AE1 mRNA was detected in only a few liver biopsy specimens of patients with PBC and control subjects, whereas AE2 mRNA was found in all liver specimens tested. In lymphoid cells, however, both transcripts were consistently detected. AE2 mRNA levels in liver as well as in lymphoid cells were significantly lower in PBC patients than in controls. In contrast to AE2 mRNA, AE1 mRNA levels were increased in lymphoid cells from patients with PBC. Interestingly, the levels of liver AE2 mRNA in a few PBC patients treated with ursodeoxycholic acid were within the range of the controls.

CONCLUSIONS

The expression of AE genes is altered in patients with PBC. It is suggested that this disturbance may have a role in the cholestasis, exocrine failure, and immunodysfunction of PBC.

Platelet-activating factor (PAF)-induced cardiopulmonary dysfunctions and their reversal with a PAF antagonist (BN 52021) in strain 13 guinea pigs

Cardiovascular and respiratory responses to a 2 h intravenous constant infusion of PAF (5 and 10 ng/kg per min) were studied in strain 13 guinea pigs. PAF decreased arterial blood pressure, left systolic ventricular pressure, and cardiac output (CO). These cardiovascular changes were dose-dependent. The PAF-induced hypotension returned to a pre-infusion level spontaneously with increased total peripheral resistance despite continuous infusion of PAF. The decreased CO was most striking, and did not recover to pre-infusion levels due to depressed cardiac contractility and impaired ventricular relaxation. Respiratory responses to PAF infusion at these doses were mild and only occurred after serious cardiovascular dysfunctions developed. A higher dose of PAF (20 ng/kg per min) produced drastically decreased CO and dynamic lung compliance (Cdyn), increased pulmonary airway resistance, hypoventilation and apnea within 10-40 min. BN 52021, a PAF receptor antagonist, administered as a single i.v. dose (6 mg/kg) 15 min after PAF infusion, reversed most of cardiopulmonary dysfunctions and prevented death by increasing cardiac contractility, CO, and minute volume from extremely low values. The data suggest that marked cardiopulmonary disturbances induced by intravenous PAF infusion reflects certain pathophysiological mechanisms of diseases that may involve the cellular release of PAF. The administration of BN 52021 or other potent PAF antagonists may be beneficial under these circumstances.

Molecular cloning of a mouse myosin I expressed in brain

We have isolated two cDNAs that encode putative myosin I heavy chains by polymerase chain reaction amplification of brain cDNA with degenerate oligodeoxynucleotide primers representing myosin I-specific conserved amino acid sequences. We report the complete deduced amino acid sequence of one of these cDNAs. The sequences is most similar to those of the avian and bovine brush border myosin Is, with five putative calmodulin-binding repeats at the head-tail junction. Northern analysis demonstrates that this myosin heavy chain, unlike the brush border myosins, is expressed in many tissues.

Vaccination of bovines against Schistosomiasis japonica with cryopreserved-irradiated and freeze-thaw schistosomula

Four laboratory tests and one field trial with cryopreserved irradiated (CI) schistosomula vaccine and a freeze-thaw (F/T) vaccine against bovine Schistosomiasis japonica were carried out in 1979 and 1980 with the following results: (1) Single intradermal vaccination in buffalo calves each with 10,000 20 krad CI Schistosomula plus 1 ml BCG gave 62% worm reduction (P < 0.05). Using the same protocol 55% worm reduction (P < 0.01) was obtained in cattle. (2) Buffalo calves immunized twice, at a 1.5 month interval, with 10,000 and 20,000 CI schistosomula, respectively, resulted in a worm reduction 65%. (3) In a preliminary field trial with 10,000 CI schistosomula plus 1 ml BCG resulted in a worm reduction of 53% in buffalo calves. (4) Intradermal vaccination of 30,000 F/T schistosomula with 1 ml BCG was also tried in cattle and revealed a worm reduction of 57% but increasing the number of vaccinations did not improve the protective effect. (5) Evidence regarding the effects of immunization with CI vaccine in buffaloes and F/T vaccine in cattle, on the number of eggs and miracidia and that of female worms themselves was obtained. (6) Immune responses, cellular and humoral, elicited in buffaloes vaccinated with CI schistosomula were detected by means of Lymphocyte Transformation Assay and Enzyme Linked Immunosorbent Assay.

The stilbene disulfonic acid DIDS stimulates the production of TNF-alpha in human lymphocytes

Exposure of human peripheral blood mononuclear cells (PBMC) to the stilbene derivative DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid) (60 microM and above) significantly increased the release of tumor necrosis factor-alpha (TNF-alpha), as determined by TNF-alpha activity in the incubation media. When the TNF-alpha message was analyzed in PBMC by a reverse transcription/polymerase chain reaction (RT/PCR)-based procedure, it was found that incubation with DIDS (60 microM) was followed by a time-dependent accumulation of TNF-alpha mRNA. Measurements of intracellular pH showed that the presence of increasing concentrations of DIDS resulted in a progressive intracellular alkalinization of PBMC. It is suggested that the known DIDS effect of inhibiting transmembrane anion exchange, i.e., chloride/bicarbonate exchange, might play a role in the stimulation of TNF-alpha production by PBMC exposed to DIDS.

Replication of hepatitis C virus in peripheral blood mononuclear cells. Effect of alpha-interferon therapy

Hepatitis C virus (HCV) is a positive-stranded RNA virus which replicates through a negative-stranded RNA intermediate. Using a PCR procedure to detect positive and negative strands, we investigated the existence of HCV replication in lymphoid cells. Both positive and negative strands were found in the peripheral blood mononuclear cells (PBMC) of all patients (n = 10) with untreated chronic hepatitis C. No HCV sequences were detected in PBMC in any of the 8 healthy controls. Fifteen patients with chronic hepatitis C were studied at the end of a 12-month course of alpha-interferon therapy. The positive strand was detected in PBMC in all 9 non-responder patients, and the negative strand in 7. In contrast, in PBMC from responder patients (n = 6) the positive strand was found in 4 and the negative strand in only 2 cases. These results demonstrate that HCV can infect PBMC and replicate in these cells and that interferon seems to exert an inhibitory effect on this process. Persistence of HCV-RNA in PBMC may help explain disease relapse after successful interferon therapy.

Increased platelet-activating factor (PAF) concentrations in hearts and lungs of Pichinde virus-infected guinea pigs

Platelet-activating factor (PAF) has been implicated as a cause of cardiopulmonary disturbances in certain diseases. In the present study, concentrations of PAF in hearts, lungs, whole blood, and other organs of control and Pichinde virus-infected guinea pigs on post-inoculation days (PID) 10 and 14 were measured by radioimmunoassay. Results were further confirmed by bioassay after separation and purification with thin-layer chromatography. PAF concentration in the hearts and lungs of virus-infected animals increased significantly on PID 10 and 14, as compared with control levels. PAF level in the blood of infected guinea pigs also significantly increased on PID 14. There was little change of PAF levels in liver and kidney after viral inoculation. Increased PAF concentrations in both hearts and lungs of infected strain 13 guinea pigs suggest that this lipid mediator may play an important role in the development of cardiopulmonary disturbances.