[Synthetic oligopeptide of hepatitis D virus antigen and its clinical application]

A 27-peptide fragment derived from natural HDAg sequence was selected, identified and synthesized. It was used to develop an EIA method for detection of anti-HD. The 27-peptide possessed the similar antigenicity with the corresponding fragment of natural HDAg, and could also compete with natural HDAg for serum anti-HD. High specificity and no cross-reaction were found among the peptide and normal human sera, normal mice sera and sera positive with HAV, HBV or HCV antibody alone. 36 serum samples were identified previously, with Abbott kits with a coincident rate of 97.2%. Anti-HD was also detected in serum samples of some blood donors and patients with liver diseases and HBV infection from 1990-1992. One (0.33%) of 300 blood donors was positive (two times higher than normal ALT level in serum). 62 patients with hepatitis A and 58 patients with non-hepatitis B were anti-HD negative. 100 (11.64%) of 859 patients with HBV infection were positive: ASC 13/410 (3.17%), AH 7/63 (10.29%), CPH 1/9 (11.11%), CAH 22/121 (18.18%), SH 15/75 (20.00%), LC 23/78 (29.49%), PHC 19/89 (19.39%). The results are consistent with our previous reports.

Hoxb-4 (Hox-2.6) mutant mice show homeotic transformation of a cervical vertebra and defects in the closure of the sternal rudiments

Two Hoxb-4 (Hox-2.6) mutations were introduced into the mouse germline. The overt phenotype caused by one of the mutations was assayed on two different genetic backgrounds, an inbred 129SvEv and a hybrid 129SvEv-C57BL/6J. The allele hoxb-4' is a disruption of the first exon and causes two obvious skeletal changes: a partial homeotic transformation of the second cervical vertebra from axis to atlas and a defective morphogenesis of the sternum. Both phenotypes have incomplete penetrance and variable expressivity when assayed in the hybrid genetic background, but the sternum defect is completely penetrant in the inbred background. The mutant allele hoxb-4s has a premature stop codon, introduced by the "hit and run" method in the second exon, that disrupts the third helix of the homeodomain. This allele also causes the partial homeotic transformation of axis to atlas, but it does not affect the sternum.

Regulation of neutrophil interleukin 8 gene expression and protein secretion by LPS, TNF-alpha, and IL-1 beta

Neutrophils are possibly involved in the pathogenesis of various lung diseases through the release of numerous mediators. In the present study, we studied the regulation of IL-8 gene induction and protein secretion in human blood neutrophils. Northern blot analysis revealed that LPS increased IL-8 mRNA levels in neutrophils, with a maximal fivefold increase by 2 h. IL-8 mRNa levels returned to baseline values within 12 h. In contrast, LPS-stimulated monocytes demonstrated a sustained increase of IL-8 mRNA levels for more than 24 h. TNF-alpha, IL-1 beta, and phorbol myristate acetate also increased IL-8 mRNA levels in neutrophils. Immunohistochemical analysis confirmed that IL-8 was localized within stimulated neutrophils. IL-8 secretion by neutrophils and monocytes was quantified using a specific ELISA for IL-8. Resting neutrophils secreted minimal IL-8 activity. However when cells were stimulated with LPS, TNF-alpha, or IL-1B, neutrophils secreted IL-8. IL-8 secretion was most marked during the first 2 h after stimulation and decreased thereafter. In contrast, monocytes maintained a high rate of IL-8 secretion over 12 h. Although a single monocyte secreted 70-fold more IL-8 than did a single neutrophil after 4 h of incubation, the high abundance of neutrophils in peripheral blood made the neutrophil-secreted IL-8 more significant. During the first 2 h, neutrophils secreted approximately 40% of the IL-8 released by monocytes in the same volume of blood. This ratio decreased to 9% after 12 h. Neutrophil-secreted IL-8 may play an autocrine or paracrine role during the initial stage of inflammation.

[Preparation of monoclonal antibody against basic glutathione S-transferase and its clinical application]

Balb/c mice were immunized with basic glutathione s-transferase (B-GST) prepared from human liver and the monoclonal antibody against B-GST was purified. Serum B-GST level was measured in 234 patients with various types of viral hepatitis with solid radioimmuno-sandwich assay and the value in 70 donors (4.19 +/- 4.42 ng/ml) used as control. The serum B-GST level in 117 cases with acute icteric hepatitis, 85 cases with chronic active hepatitis and 32 cases with severe hepatitis were 8.6, 8.4 and 5.9 times higher than that of the controls respectively. At the same time, serum alanine amino-transferase (ALT) activity in patients with various types of viral hepatitis were 6.8, 3.1 and 2.4 times higher respectively. These results showed that the change of serum B-GST level was more prominent than that of ALT activity. In addition, the change of B-GST in 35 patients with CAH and 13 with severe hepatitis were serially observed. Serum B-GST level persisted at high level for a long time in most of the patients, while serum ALT activity soon became normal. It is shown that serum B-GST level is more valuable than ALT in estimating chronic and severe liver damage.

An error-weighted regularization algorithm for image motion-field estimation

Local motion measurement errors are used to guide the global smoothing process in order to preserve motion-field discontinuities. A field-smoothing algorithm based on matching-error weighting is proposed. The added computation is minimal, since it uses byproducts of the local measurement process. The error-weighting functional provides significantly improved motion field estimates, as measured by motion-compensated interpolation performance. However, the mean-square reconstruction error is somewhat higher than that obtained by performing the much more computationally expensive stochastic optimization.

Antisense oligodeoxynucleotides as probes of T-lymphocyte gene function

Conventional and thiophosphonate-derivatized oligonucleotides were employed to specifically regulate functional gene expression in murine T-cell hybridomas. For example, induction of apoptotic cell death following activation of T-cell hybridomas was examined using antisense oligonucleotides corresponding to several protooncogenes. We found that antisense oligodeoxynucleotides corresponding to c-myc inhibited both the characteristic DNA fragmentation and the loss of cell viability following activation without affecting production of lymphokines. Functional antisense oligonucleotides corresponding to c-fos had no effect in this system. These results demonstrate the use of antisense oligonucleotides to regulate function in T-cell hybridomas and provide valuable insights into the molecular bases of this biological phenomenon. Antisense oligonucleotides were also used to study another problem, the relation of T-cell-derived antigen-specific immunoregulatory factors to the T-cell receptor (TCR). Because the translation start of each TCR gene usually varies from one T cell to another, antisense oligonucleotides corresponding to the TCR V alpha or V beta of different cells were shown to act in a cell-specific manner. Furthermore, this method was used to demonstrate that a soluble antigen-specific regulatory activity produced by one of the T-cell lines depends on expression of the specific TCRa, an observation that has since been confirmed by gene transfer experiments. Expression of the CD3-TCR complex on the cell surface was also blocked by antisense oligonucleotides corresponding to CD3 gamma and CD3 zeta; however, neither these nor TCR V beta antisense oligonucleotides had any effect on production of the soluble regulatory activity.

Editing on the genomic RNA of human hepatitis delta virus

It has been shown previously that during replication of the genome of human hepatitis delta virus (HDV), a specific nucleotide change occurs to eliminate the termination codon for the small delta antigen (G. Luo, M. Chao, S.-Y. Hsieh, C. Sureau, K. Nishikura, and J. Taylor, J. Virol. 64:1021-1027, 1990). This change creates an extension in the length of the open reading frame for the delta antigen from 195 to 214 amino acids. These two proteins, the small and large delta antigens, have important and distinct roles in the life cycle of HDV. To further investigate the mechanism of this specific nucleotide alteration, we developed a sensitive assay involving the polymerase chain reaction to monitor changes on HDV RNA sequences as they occurred in transfected cells. We found that the substrate for the sequence change was the viral genomic RNA rather than the antigenomic RNA. This sequence change occurred independently of genome replication or the presence of the delta antigen. Less than full-length genomic RNA could act as a substrate, but only if it also contained a corresponding RNA sequences from the other side of the rodlike structure, which is characteristic of HDV. We were also able to reproduce the HDV base change in vitro, by addition of purified viral RNA to nuclear extracts of cells from a variety of species.

Chlorhexidine effects on membrane lipid domains of human buccal epithelial cells

The effect of chlorhexidine gluconate on the adherence of Candida albicans to human buccal epithelial cells (BEC) and drug-induced alterations in BEC membrane-lipid packing order were examined. Treatment of BEC with attached yeasts with 0.1 and 0.2% chlorhexidine resulted in significant yeast detachment after 90 and 60 min, respectively. Following pre-treatment of BEC with greater than 0.1% chlorhexidine, yeast adherence was inhibited by greater than 80%. In parallel experiments, the fluorescence anisotropy of BEC labeled with fluorescent membrane probes--diphenylhexatriene (DPH) and trimethylammonium DPH--was assessed following exposure to chlorhexidine. The fluorescence anisotropy decreased with increasing concentrations of chlorhexidine, which indicated that the drug decreased epithelial-cell membrane-lipid packing order. Chlorhexidine concentrations that altered epithelial-cell membrane-lipid packing order, particularly in superficial regions, were similar to those drug concentrations required for detachment of adherent yeasts. Similar results were obtained with a second antifungal, nystatin A. While the effects of chlorhexidine on the buccal-cell membrane-lipid packing order were not reversed by multiple washings, the opposite situation occurred with nystatin A. The results suggest that chlorhexidine-induced alterations of BEC membrane-lipid order may be involved in the antifungal actions of the drug.

[A new virus of rabbit. II. Study on morphological structure and some physicochemical properties of a strain of rabbit hemorrhagic disease virus]

In this paper a strain of Rabbit Hemorrhagic Disease Virus (RHDV) was isolated and purified from the diseased rabbit livers with a method of using chloroform, two-phase of polyethylene-glycol-dextran sulfate sodium and sucrose density gradient centrifugation. Purified virus was nonenveloped, icosahedeal symmetry with a triangulation number of 3, and 33-37 nm in diameter. The capsid was composed of 32 capsomeres with central holes in an outer diameter of about 9nm. Two types of viral particles having different sedimentation coefficient, 130s and 166s could be identified after sucrose density gradient centrifugation. Probably no less than four virion proteins with molecular weight of 66.4, 65.0, 63.5, 41.0 x 10(3) dalton were detected by SDS-polyacrylamide gel electrophoresis. Viral nucleic acid was extracted from purified virus by using SDS-proteinase K-phenol. Tests with diphenylamine, formaldehyde, and staining with acridine orange as well as the curves of thermal denaturation showed that this kind of virus had a single-stranded DNA. The molecular weight of the ssDNA was approx 2.1 x 10(6) dalton as determined by electron microscopy. Data indicate that the RHDV may like the parvovirus of the family Parvoviridae.

Nuclear morphometry and its prognostic significance in laryngeal squamous cell carcinomas

The five parameters including nuclear area (NA), nuclear perimeter (NP), nuclear diameter (ND), axis ratio and nuclear roundness were evaluated with MIAS200 Image Analysis System (Sichuan University, Chengdu) in 45 patients with laryngeal primary squamous cell carcinoma, which were confirmed pathologically and operated on from January 1977 to October 1987. The results showed that NA, NP and ND are important prognostic indicators. The survival rate in patients with large nuclei (NA greater than 73 microns2, NP greater than 32.5 microns, ND greater than 12 microns) was significantly lower than that in those with small nuclei (NA less than 73 microns2, NP less than 32.5 microns, ND less than 12 microns) (P less than 0.0025). These findings strongly suggest that patients with laryngeal squamous cell carcinoma with large nuclei should be treated more aggressively.

Genomic DNA microextraction: a method to screen numerous samples

Many experimental designs require the analysis of genomic DNA from a large number of samples. Although the polymerase chain reaction (PCR) can be used, the Southern blot is preferred for many assays because of its inherent reliability. The rapid acceptance of PCR, despite a significant rate of false positive/negative results, is partly due to the disadvantages of the sample preparation process for Southern blot analysis. We have devised a rapid protocol to extract high-molecular-weight genomic DNA from a large number of samples. It involves the use of a single 96-well tissue culture dish to carry out all the steps of the sample preparation. This, coupled with the use of a multichannel pipette, facilitates the simultaneous analysis of multiple samples. The procedure may be automated since no centrifugation, mixing, or transferring of the samples is necessary. The method has been used to screen embryonic stem cell clones for the presence of targeted mutations at the Hox-2.6 locus and to obtain data from human blood.

Proteus penneri isolated from the pus of a patient with epidural abscess

P. mirabilis and P. vulgaris are the two wellknown species in the genus Proteus. P. myxofaciens and P. penneri are recent additions to the genus. We isolated P. penneri from the pus of a patient with suppurative otitis media and an epidural abscess. The characteristics of the organism, including morphology, staining, physiology and biochemistry, were studied. Clinical microbiological laboratories should suspect P. penneri in the case of as Proteus strain that is negative for indole, salicin and esculin, but otherwise resembles P. vulgaris. Proteus penneri, formerly known as Proteus vulgaris indole-negative or as Proteus vulgaris biogroup 1, was named by Hickman et al in 1932. Little information about human infection by this organism is available. In 1982, Hickman and co-workers studied 20 strain of P. penneri which were isolated from clinical specimens (urine, stool, etc.) in the USA. However, its clinical significance, until recently, was unknown. We isolated a strain of P. penneri from the pus of a patient with suppurative otitis media and an epidural abscess on June 10 and 15, 1989. This paper concerns the problems encountered in identifying this organism and its clinical significance.

The lysine analog L-oxalysine is an inhibitor of RNA synthesis

1. The lysine analog L-4-oxalysine was found to be a potent inhibitor of RNA synthesis in Candida albicans. 2. The compound was a weak inhibitor of protein synthesis and DNA synthesis was not affected. 3. The inhibition of RNA synthesis was reversed by L-lysine but not D-lysine. 4. The decrease in the level of newly synthesized RNA in cells treated with L-oxalysine was due to inhibition of de novo synthesis rather than to degradation of RNA.

Fidelity of targeted recombination in human fibroblasts and murine embryonic stem cells

Targeted recombination in murine embryonic stem cells promises to be a powerful tool for introducing specific mutations into target genes to study development in mice and to create animal models of human disease. Gene targeting also holds potential for correcting genetic defects as an approach to human gene therapy. To precisely modify target genes, homologous recombination must proceed with high fidelity. However, several results have suggested that targeted recombination may be highly mutagenic. To test the accuracy of gene targeting we analyzed 44 independent targeted recombinants at the hypoxanthine phosphoribosyltransferase (HPRT) locus in a human fibroblast cell line and in mouse embryonic stem cells. We surveyed 80 kilobases around the sites of recombination by using chemical cleavage of mismatches. Only two mutations were found: a T----G transversion and a thymidine deletion. Thus, gene targeting in mammalian cells can be extremely accurate. These results demonstrate the feasibility of generating precise modifications of mammalian genomes by gene targeting.

Induction and localization of Plasmodium falciparum stress proteins related to the heat shock protein 70 family

Induction of heat shock-related stress proteins Pfhsp and Pfgrp, similar in sequence to hsp70 (heat shock protein) and grp78 (glucose-regulated protein), respectively, was studied in culture-derived parasite Plasmodium falciparum. Elevation in temperature from 26 degrees C to 37 degrees C and higher caused significant induction of Pfhsp with a moderate effect on the synthesis of Pfgrp also. Synthesis of Pfgrp, however, was not induced by partial glucose deprivation. On the contrary, lack of glucose in the medium resulted in cessation of protein synthesis in the parasites. Other known inducers of grp synthesis in mammalian cells, i.e., calcium ionophore A23187 and inhibitors of glycosylation (tunicamycin, 2-deoxy glucose) were also without any apparent effect on the synthesis of Pfgrp. Heat shock-induced responses were transient in nature: removal of stress caused repression of these responses. The effect of glucose deprivation was only partially reversible with better recovery if parasites were subjected to glucose starvation at 26 degrees C than at 37 degrees C. Northern blot analysis and in vitro translation of mRNA revealed a parallel increase in the levels of mRNA for Pfhsp upon heat shock. Immuno-gold electron microscopy with cultured parasites revealed nuclear location of Pfhsp and primarily cytoplasmic (probably endoplasmic reticulum) location of Pfgrp. These findings suggest that SDEL (carboxy terminal sequence of Pfgrp) might play a similar role in the cellular localization of Pfgrp as does the sequence KDEL in mammalian cells and HDEL in yeast.

Pentoxifylline does not attenuate acute lung injury in the absence of granulocytes

Pentoxifylline (PTX), a methylxanthine, can suppress polymorphonuclear leukocyte (PMN) activation and attenuate sepsis-induced acute lung injury. We investigated whether PTX prevents non-PMN-dependent lung injury. First we studied four groups of granulocyte-depleted guinea pigs (control, PTX, Escherichia coli, and E. coli + PTX). Lung injury was assessed by wet-to-dry lung weight (W/D) ratio and lung tissue-to-plasma 125I-albumin ratio (albumin index, AI). The E. coli group showed a significant increase in the lung W/D ratio and AI compared with the control and PTX groups. However, PTX did not prevent the E. coli-induced increase in the lung W/D ratio and AI. Next we investigated the effects of PTX on endothelial cell monolayer permeability and adenosine 3',5'-cyclic monophosphate (cAMP) levels. Whereas E. coli lipopolysaccharide (LPS) alone increased the endothelial permeability, PMNs added to the endothelial monolayers and exposed to LPS enhanced the increase. PTX attenuated the permeability increase mediated by LPS-exposed PMNs. PTX did not prevent the LPS-induced increase in permeability when PMNs were not present, although PTX increased endothelial cell cAMP levels. These data demonstrate that 1) PTX does not prevent lung injury in granulocyte-depleted guinea pigs; 2) PTX does not prevent LPS-induced increases in endothelial cell permeability, despite increased cAMP levels; and 3) PTX attenuates PMN-dependent increases in endothelial cell permeability.

[Glycosaminoglycans associate with corneal transparency]

Keratoplasty specimens form 12 patients with macular corneal dystrophy, 1 patient with systemic glycosaminoglycan stored disease and 12 cases of normal cornea were studied by electron-histochemistry. The results showed that the normal cornea contains chondroitin sulfate in the basement membrane and bowman's membrane, Keratan sulfate and chondroitin sulfate between the collagen fibrils of strome, heparan sulfate on the cell membranes of various cells, and hyaluronic acid on the surface of endothelial cell. The chondroitin sulfate of the stroma of macular corneal dystrophy increases, but the keratan sulfate is absent. The keratocytes and endothelial cells of macular corneal dystrophy synthesize fibrillogranular material and abnormal glycosaminoglycan. The heparan sulfate is stored in the cytoplasm of corneal epithelial cell and keratocyte of systemic glycosaminoglycan stored disease and absent on the membrane of involved cells. The authors suggest that glycosaminoglycan play important role in maintaining corneal transparency and the changes of distribution, character and quantity of glycosaminoglycan in the cornea cause corneal opaqueness.

Attenuation of LPS-induced neutrophil thromboxane b2 release and chemiluminescence

Polymorphonuclear leukocytes (PMN) may play a key role in acute lung injury and ARDS. The mechanisms of PMN-mediated lung injury include the release of inflammatory mediators, such as oxygen free radicals which cause direct tissue injury, and arachidonic acid metabolites which cause pulmonary vasoconstriction and increased vascular permeability. The goals of this in vitro study were 1) to assess the effects of PMN-activating agents (lipopolysaccharide, LPS; phorbol myristate acetate, PMA; tumor necrosis factor, TNF) on PMN thromboxane B2 (TXB2) release and oxygen free radical production and 2) to determine the effects of agents purported to suppress PMN activity (pentoxifylline, PTX; adenosine; dibutyryl cyclic AMP, DBcAMP; and terbutaline, TBN) on activator-induced PMN TXB2 release and oxygen free radical production. PMN TXB2 release was determined by radioimmunoassay and oxygen free radical production was monitored by chemiluminescence. Our results show that 1) LPS and PMA significantly increase PMN TXB2 release, whereas tumor necrosis factor (TNF) has no effect; 2) LPS and PMA significantly increase PMN chemiluminescence; 3) DBcAMP and TBN significantly reduce LPS-induced PMN TXB2 release whereas PTX and adenosine do not; 4) TBN significantly reduces PMA-induced PMN TXB2 release whereas other agents do not; 5) All agents (PTX, adenosine, DBcAMP, and TBN) significantly reduce LPS-induced PMN chemiluminescence but none attenuate PMA-induced PMN chemiluminescence. We conclude that: LPS and PMA activate PMN manifested by TXB2 release and chemiluminescence. Additionally, all the PMN suppressing agents do attenuate some PMN functions. Of interest, PTX, adenosine, DBcAMP, and TBN have different effects depending upon functional assay and activating agent. It will be important to investigate the mechanisms by which PMN suppressing agents alter signal transduction resulting in differential effects on PMN function.

Early post-treatment with pentoxifylline or dibutyryl cAMP attenuates Escherichia coli-induced acute lung injury in guinea pigs

We examined effects of early post-treatment with the methylxanthine pentoxifylline (PTXF), or the cell-permeable adenosine 3', 5'-cyclic monophosphate (cAMP) analog dibutyryl cAMP (db-cAMP) on Escherichia-coli-induced acute lung injury in guinea pigs. Acute lung injury was assessed by measurements of lung water (lung wet/dry weight ratio; W/D ratio), the concentration ratio of 125I-albumin in bronchoalveolar lavage (BAL) fluid and lung tissue compared with plasma (albumin index; BAL-AI or tissue-AI), and total differential leukocyte count in BAL fluid. Mean arterial pressure (Pa) and peripheral WBC counts were monitored continuously over the 8-h experiment. Septicemia was induced by a bolus injection of 2 x 10(9)/kg live E. coli. Thirty minutes later the animals received a bolus injection followed by continuous infusion of PTXF (20 mg/kg + 20 mg/kg/h; n = 8) or db-cAMP (2 mg/kg + 2 mg/kg/h; n = 8) or saline (septic control; n = 8). Nonseptic control groups were also studied. The lung W/D ratio, BAL-AI, lung tissue-AI, and BAL leukocyte count increased significantly in the septic control group. The PTXF-septic and db-cAMP-septic groups showed no significant increase in lung W/D ratio, BAL-AI, and lung tissue-AI. However, there was no difference in BAL total and differential leukocyte count as compared with the septic control group. PTXF and db-cAMP had no effect on E. coli-induced changes in peripheral WBC count and Pa. Comparison in vitro experiments demonstrated that PTXF and db-cAMP inhibited the endotoxin-induced (E. coli) chemiluminescent response of isolated guinea-pig polymorphonuclear leukocytes (PMN).(ABSTRACT TRUNCATED AT 250 WORDS)