Antipyrine clearance and response to interferon treatment in patients with chronic active hepatitis C

To determine whether hepatic metabolic function affects the response to interferon treatment, we measured antipyrine clearance (APC) in 85 patients with chronic active hepatitis C and compared the results with treatment outcome. Among 55 patients who responded to interferon by normalization of alanine transaminase (ALT), median APC before treatment was 0.47 (range, 0.12 to 0.98; normal range, 0.34 to 1.02 mL/min/kg body wt), a value that was significantly greater than in 30 nonresponders (0.23; 0.08 to 0.67 mL/min/kg body wt, P < .001). APC was closely associated with response to interferon. The response rate among cases with values > 0.25 mL/min/kg body weight was 79%, the same as in cases without cirrhosis. Cases without cirrhosis and with APC of > 0.25 mL/min/kg body weight had an 85% chance of responding to interferon; this was unlikely a simple reflection of histological activity, because the correlation with Scheuer score was poor in this subgroup (r = -.31, P < .05). A second, independent group of 43 patients was used to test the predictive value of APC (using 0.25 mL/min/kg body wt as a cut-off) for response to interferon treatment. In this group, APC correctly predicted positive response to interferon in 75% of cases. APC was also used to measure the effects of treatment on hepatic metabolic function. Regardless of outcome, there was no change in APC at the end of a 6-month course of interferon treatment. Six months later, however, improvement in APC (14%; P < .05) was evident among responders but not in those who had failed to respond to interferon.(ABSTRACT TRUNCATED AT 250 WORDS)

Leucine-responsive regulatory protein: a global regulator of gene expression in E. coli

The leucine-responsive regulatory protein (Lrp) regulates transcription of the many genes of the Lrp regulon, repressing some and activating others, some in response to L-leucine and some independent of it. The physiology and molecular biology of the regulon in Escherichia coli are summarized here. However, the high degree of conservation of the protein suggests that it has an important role in all enterobacteria. We suggest that this role is not only as a transcriptional regulator but also as a determinant of chromosome structure.

Regulation of human immunodeficiency virus type 1 and cytokine gene expression in myeloid cells by NF-kappa B/Rel transcription factors

CD4+ macrophages in tissues such as lung, skin, and lymph nodes, promyelocytic cells in bone marrow, and peripheral blood monocytes serve as important targets and reservoirs for human immunodeficiency virus type 1 (HIV-1) replication. HIV-1-infected myeloid cells are often diminished in their ability to participate in chemotaxis, phagocytosis, and intracellular killing. HIV-1 infection of myeloid cells can lead to the expression of surface receptors associated with cellular activation and/or differentiation that increase the responsiveness of these cells to cytokines secreted by neighboring cells as well as to bacteria or other pathogens. Enhancement of HIV-1 replication is related in part to increased DNA-binding activity of cellular transcription factors such as NF-kappa B. NF-kappa B binds to the HIV-1 enhancer region of the long terminal repeat and contributes to the inducibility of HIV-1 gene expression in response to multiple activating agents. Phosphorylation and degradation of the cytoplasmic inhibitor I kappa B alpha are crucial regulatory events in the activation of NF-kappa B DNA-binding activity. Both N- and C-terminal residues of I kappa B alpha are required for inducer-mediated degradation. Chronic HIV-1 infection of myeloid cells leads to constitutive NF-kappa B DNA-binding activity and provides an intranuclear environment capable of perpetuating HIV-1 replication. Increased intracellular stores of latent NF-kappa B may also result in rapid inducibility of NF-kappa B-dependent cytokine gene expression. In response to secondary pathogenic infections or antigenic challenge, cytokine gene expression is rapidly induced, enhanced, and sustained over prolonged periods in HIV-1-infected myeloid cells compared with uninfected cells. Elevated levels of several inflammatory cytokines have been detected in the sera of HIV-1-infected individuals. Secretion of myeloid cell-derived cytokines may both increase virus production and contribute to AIDS-associated disorders.

Transcription factor IRF-2 exerts its oncogenic phenotype through the DNA binding/transcription repression domain

The Interferon Regulatory Factors-1 and -2 (IRF-1 and IRF-2) play a transcriptional role in the regulation of the IFN-beta gene as well as other immunoregulatory genes. IRF-1 serves as a transcriptional activator whereas IRF-2 acts as an antagonistic transcriptional repressor. IRF-1 and IRF-2 also play opposing functional roles in cell growth regulation, and are implicated as a potential antioncogene and oncogene, respectively. To analyse the relationship between DNA binding/transcriptional repression and oncogenic transformation, NIH3T3 cells expressing C-terminal deletions of IRF-2 were established and assayed for transformation by saturation density analysis, anchorage independent growth in soft agar and tumor formation in nude mice. Cells expressing an IRF-2 protein of at least 160 N-terminal amino acids were transformed in vitro and tumorigenic in vivo, thus mapping IRF-2 oncogenic activity to its DNA binding/transcriptional repression domain. Overexpression of wild-type and truncated IRF-2 proteins resulted in reduced IFN-beta mRNA levels following induction by dsRNA. However, there was no effect of IRF-2 on IFN-beta inducibility by Sendai virus infection, suggesting the involvement of multiple IFN-beta induction pathways. In DNA binding assays, recombinant IRF-2 was found to preferentially bind to the IFN-beta PRDI site compared to IRF-1. These studies indicate that the transformed phenotype resulting from overexpression of IRF-2 may be due to constitutive engagement of the IRF-E recognition site, thus preventing DNA binding and transactivation of putative tumor suppressor genes by the IRF-1 anti-oncogene.

Retrovirus-mediated transfer of nuclear factor-kappa B subunit genes modulates I kappa B alpha and interferon beta expression

Nuclear factor (NF)-kappa B proteins regulate the transcription of numerous genes involved in the immune response, transcription control, and viral pathogenesis. To examine the effect of ectopic expression of NF-kappa B proteins on DNA-binding activity and gene expression, individual NF-kappa B subunit genes were introduced into NIH 3T3 cells via retrovirus-mediated gene transfer. Expression of NF-kappa B subunits RelA (p65), NF-kappa B1 (p105), NF-kappa B2 (p100), and c-Rel increased the basal level of nuclear NF-kappa B DNA binding in NIH 3T3 cells, whereas expression of delta RelA (p65 delta) and NF-kappa B2 (p52) subunits did not affect basal level activity. Tumor necrosis factor-alpha treatment of the NF-kappa B-expressing cells stimulated the induced level of DNA-binding activity, reflecting interaction between endogenous murine and transfected human NF-kappa B proteins. Interestingly, expression of RelA (p65), c-Rel, NF-kappa B1 (p105), NF-kappa B2 (p100), and NF-kappa B2 (p52) subunits increased I kappa B alpha protein levels from 3- to 30-fold, indicating that one mechanism to compensate for the increased expression of NF-kappa B proto-oncogenes was to increase the synthesis and/or stability of the regulatory I kappa B alpha protein. In addition, overexpression of RelA (p65), c-Rel, NF-kappa B2 (p100), and NF-kappa B2 (p52) altered the induction kinetics of IFN-beta mRNA after Sendai virus infection, whereas overexpression of NF-kappa B1 (p105) dramatically decreased IFN-beta mRNA induction.

Differential transcriptional activation in vitro by NF-kappa B/Rel proteins

Distinct NF-kappa B subunit combinations contribute to the specificity of NF-kappa B-mediated transcriptional activation and to the induction of multiple cytokine genes including interferon-beta (IFN-beta). To evaluate the regulatory influence of different homo- and heterodimers, NF-kappa B subunits were analyzed for transcriptional activity in vitro using test templates containing two types of NF-kappa B recognition elements (the human immunodeficiency virus type 1 enhancer and the IFN-beta-positive regulatory domain-II (PRDII) as well as IFN-beta PRDIII-PRDI-PRDII linked to the -56 minimal promoter of rabbit beta-globin. Recombinant NF-kappa B subunits (p50, p65, c-Rel, p52, and I kappa B alpha) and interferon regulatory factor 1 were produced from either Escherichia coli or baculovirus expression systems. Transcriptional analysis in vitro demonstrated that 1) various dimeric complexes of NF-kappa B differentially stimulated transcription through the human immunodeficiency virus enhancer or PRDII up to 20-fold; 2) recombinant I kappa B alpha specifically inhibited NF-kappa B-dependent transcription in vitro; and 3) different NF-kappa B complexes and interferon regulatory factor 1 cooperated to stimulate transcription in vitro through the PRDIII-PRDI-PRDII virus-inducible regulatory domains of the IFN-beta promoter. These results demonstrate the role of NF-kappa B protein dimerization in differential transcriptional activation in vitro and emphasize the role of cooperativity between transcription factor families as an additional regulatory level to maintain transcriptional specificity.

Subcellular redistribution of HTLV-1 Tax protein by NF-kappa B/Rel transcription factors

The viral oncogene Tax derived from human T cell leukemia virus type I (HTLV-I) is a positive transcriptional activator of HTLV-1 gene expression. Tax is also able to indirectly stimulate transcription of several growth regulatory genes by an indirect mechanism via association with host transcription factors. One of the cellular targets of the trans-activating effects of Tax is the NF-kappa B/Rel family transcription factors, pleiotropic regulators of immunoregulatory, cytokine, and viral gene expression. Recent studies demonstrated that specific subunits of NF-kappa B (NFKB2(p 100) and c-Rel) were overexpressed in HTLV-I-infected and Tax-expressing cells. Furthermore, Tax physically associated with NFKB2(p 100). Monospecific antibodies directed against individual NF-kappa B subunits were generated and used to investigate the consequences of the interactions between Tax and NF-kappa B in a cotransfection-immunofluorescence assay. These studies demonstrate: (1) distinct compartmentalization of NF-kappa B precursors and products, (2) differential induction of the endogenous I kappa B alpha protein by transfected NF-kappa B subunits, (3) subcellular relocalization of Tax to the cytoplasm or nucleus depending on the coexpressed NF-kappa B subunit, and (4) Tax interaction with the Rel homology domain region of NFKB2. These studies indicate that the transcription modulatory influence of HTLV-I Tax may be significantly influenced by cytoplasmic-nuclear partitioning associated with the NF-kappa B proteins.

Demonstration of differences in vascular permeability in experimental tumors by use of 19F magnetic resonance imaging

RATIONALE AND OBJECTIVES

In vivo assessment of tumor vascular permeability may provide useful information for chemotherapy treatment planning or for the assessment of treatment effectiveness. We aimed to assess vascular permeability in two tumor sublines as well as changes in vascular permeability with tumor growth by using 19F magnetic resonance imaging.

METHODS

An emulsion of perfluorotributylamine was used as a tumor extravascular contrast agent for 19F MRI. The amount of emulsion that leaked into tumor interstitial space was analyzed qualitatively with imaging. A quantitative study of vascular permeability was done with a separate group of tumors by use of Evans blue dye.

RESULTS

One tumor type was more permeable to both perfluorotributylamine emulsion and Evans blue than was the second tumor type. The difference was attributed to a difference in surface area for exchange. In larger tumors of both types, pooling of large amounts of perfluorocarbon occurred and was assumed to be attributable to hemorrhage or blood flow stasis or both.

CONCLUSION

19F MRI is capable of demonstrating the permeability of tumor vessels to macromolecular substances.

A Salmonella protein that is required for resistance to antimicrobial peptides and transport of potassium

The ability of invading pathogens to proliferate within host tissues requires the capacity to resist the killing effects of a wide variety of host defense molecules. sap mutants of the facultative intracellular parasite Salmonella typhimurium exhibit hypersensitivity to antimicrobial peptides, cannot survive within macrophages in vitro and are attenuated for mouse virulence in vivo. We conducted a molecular genetic analysis of the sapG locus and showed that it encodes a product that is 99% identical to the NAD+ binding protein TrkA, a component of a low-affinity K+ uptake system in Escherichia coli. SapG exhibits similarity with other E. coli proteins implicated in K+ transport including KefC, a glutathione-regulated efflux protein, and Kch, a putative transporter similar to eukaryotic K+ channel proteins, sapG mutants were killed by the antimicrobial peptide protamine in the presence of both high and low K+, indicating that protamine hypersensitivity is not due to K+ starvation. Strains with mutations in sapG and either sapJ or the sapABCDF operon were as susceptible as sapG single mutants, suggesting that the proteins encoded by these loci participate in the same resistance pathway. SapG may modulate the activities of SapABCDF and SapJ to mediate the transport of peptides and potassium.

Viral induction of the human beta interferon promoter: modulation of transcription by NF-kappa B/rel proteins and interferon regulatory factors

Multiple regulatory domains within the -100 region of the beta interferon (IFN-beta) promoter control the inducible response of the IFN gene to virus infection. In this study, we demonstrate that the formation of NF-kappa B-specific complexes on the positive regulatory domain II (PRDII) precedes the onset of detectable IFN-beta transcription in Sendai virus-infected cells. By using NF-kappa B subunit-specific antibodies, a temporal shift in the composition of NF-kappa B subunits in association with the PRDII domain is detected as a function of time after virus infection. Furthermore, a virus-induced degradation of I kappa B alpha (MAD3) protein is observed between 2 and 8 h after infection; at later times, de novo synthesis of I kappa B alpha restores I kappa B alpha to levels found in uninduced cells and correlates with the down regulation of IFN-beta transcription. In cotransfection experiments using various NF-kappa B subunit expression plasmids and two copies of PRDII/NF-kappa B linked to a chloramphenicol acetyltransferase reporter gene, we demonstrate that expression of p65, c-Rel, or p50 or combinations of p50-p65 and p65-c-Rel differentially stimulated PRDII-dependent transcription. Coexpression of I kappa B alpha completely abrogated p65-, c-Rel-, or p65-p50-induced gene activity. When the entire IFN-beta promoter (-281 to +19) was used in coexpression studies, synergistic stimulation of IFN-beta promoter activity was obtained when NF-kappa B subunits were coexpressed together with the IFN regulatory factor 1 (IRF-1) transcription factor. Overexpression of either I kappa B or the IRF-2 repressor was able to abrogate inducibility of the IFN-beta promoter. Thus, multiple regulatory events--including differential activation of DNA-binding NF-kappa B heterodimers, degradation of I kappa B alpha, synergistic interaction between IRF-1 and NF-kappa B, and decreased repression by I kappa B and IRF-2--are all required for the transcriptional activation of the IFN-beta promoter.

Mutational analysis of interferon (IFN) regulatory factors 1 and 2. Effects on the induction of IFN-beta gene expression

Interferon (IFN) regulatory factor 1 (IRF-1) and IRF-2 are structurally similar but functionally distinct transcription factors that bind to the positive regulatory domains I and III (PRDI/III) within the human IFN-beta promoter. To begin structure-function analysis of IRF-1 and IRF-2, the regulatory potential of carboxyl-terminal deletion mutants was analyzed by co-transfection studies in human cells and was correlated with DNA binding capacity. Transcriptional repression by IRF-2 was contained within the first 125 amino-terminal amino acids and correlated directly with IRF-2 DNA binding; deletion to a protein of 100 amino acids resulted in loss of repression and IRF-2 DNA binding. Thus, the carboxyl terminus appears dispensible for trans-repression. Hybrid constructs which fuse the DNA binding domain of IRF-1 and IRF-2 to the trans-activation domain of NF-kappa B p65 were also generated; both IRF-1/p65 and IRF-2/p65 chimeras were strong transcriptional activators. IRF-2-mediated repression was also dominant over trans-activation by these fusion proteins. The trans-activation region of IRF-1 resides in the carboxyl terminus, primarily carboxyl-terminal to amino acid 250. Mutation of three potential casein kinase II phosphorylation sites within the IRF carboxyl terminus failed to identify an essential site that contributes to IRF-1 trans-activation potential.

Comparative efficacy of topical ciprofloxacin for treating Mycobacterium fortuitum and Mycobacterium chelonae keratitis in an animal model

Mycobacterium fortuitum and M. chelonae are the two most common causes of nontuberculous mycobacterial keratitis, and they may be difficult to differentiate at diagnosis. Mycobacterium fortuitum is generally more sensitive to ciprofloxacin in vitro than is M. chelonae. Using a rabbit model, we compared the efficacy of topical ciprofloxacin (3 mg/ml) against M. chelonae keratitis to its efficacy against M. fortuitum keratitis. After four days of therapy, ciprofloxacin significantly reduced the number of both organisms in treated eyes compared to untreated control eyes (both P values < .001). Mean culture ratios (colony-forming units in treated eye divided by colony-forming units in untreated eye for each rabbit) were used to compare efficacy between groups. When all treated animals were considered, no significant difference was found between groups (P = .13). When outlier values were excluded, ciprofloxacin was more effective against M. fortuitum than M. chelonae (P = .01). When treated and untreated eyes were compared after therapy in the M. fortuitum group, ciprofloxacin treatment was associated with a reduction in mean stromal infiltrate area (P = .03) and in the tendency to form satellite lesions (P = .07). A clinical effect was not observed in the M. chelonae group. Although ciprofloxacin is effective against both organisms, it appears to be less effective against M. chelonae than M. fortuitum in vivo.

Thioallyl compounds: potent inhibitors of cell proliferation

S-Allylmercaptocysteine was shown to inhibit vascular smooth-muscle and umbilical endothelial cell proliferation. Inhibition was dose-dependent and affected smooth-muscle cells more than endothelial cells. S-Allylmercaptocysteine was two orders of magnitude more potent than S-allylcysteine and cells grown in its presence showed distinct changes in their phosphorylation compared to untreated controls. Among the proteins whose phosphorylation was altered were GTP-activating protein, protein tyrosine phosphatase-1B and p34cdc2. We conclude that thioallyl compounds, natural constituents of garlic and known to inhibit malignant cells, can also reduce the proliferation of normal cells.

Potential role of granulocyte-macrophage colony-stimulating factor as vaccine adjuvant

The uses of GM-CSF as an immunomodulator and vaccine adjuvant are reviewed. GM-CSF has a variety of effects on immune responses: it induces class II major histocompatibility complex antigen expression on the surface of macrophages; it enhances dendritic cell maturation and migration; it results in a localized inflammation at the injection site; and it has marked effects on maturation of haematopoietic progenitor cells in the bone marrow. Animal and human studies suggest that administration of GM-CSF can increase antibody titres to foreign antigens. Monkeys injected with human interleukin (IL)-3 plus GM-CSF, at a different injection site, developed peak antibody titres which were 8- to 30-fold higher than those in monkeys injected with IL-3 alone. In a study of ovarian cancer patients receiving GM-CSF to prevent chemotherapy-induced neutropenia, two patients who had demonstrated a low titre of antithyroid antibodies prior to the study showed an increase in antibody titre and transient thyroiditis after administration of GM-CSF. Recently a GM-CSF/antigen fusion protein has been tested. An antibody corresponding to a specific idiotype expressed on B-cell lymphomas was fused to GM-CSF and injected into mice with B-cell lymphoma xenografts. The mice developed antibodies to the lymphoma and there was a protective effect against disease progression. Preliminary results of clinical trials using GM-CSF in humans suggest that it enhances antibody responses to hepatitis B vaccine. On the basis of these preliminary results, several clinical trials are being planned and it would appear that GM-CSF has potential as a vaccine adjuvant.

Comparison of topical antibiotics for treating Mycobacterium fortuitum keratitis in an animal model

The efficacy of three topical antibiotic treatments for Mycobacterium fortuitum (strain ATCC-6841) keratitis were compared in rabbits. Rabbits were treated with ciprofloxacin (3 mg/ml) or clarithromycin (20 mg/ml) or a combination of amikacin (100 mg/ml) and vancomycin (50 mg/ml). All three treatments significantly reduced the number of organisms in treated eyes compared to untreated, control eyes (all P values < .001). No significant difference in treatment efficacy was found between the three treatment groups (all P values > or = .48), although ciprofloxacin (3 mg/ml) was more effective than clarithromycin (20 mg/ml) after excluding outliers (P = .01). All treatments stabilized or reduced the size of stromal infiltrates after four days of therapy, whereas infiltrates continued to enlarge in untreated eyes. These results suggest that topical clarithromycin, topical ciprofloxacin, and combined amikacin and vancomycin may all be clinically useful for treating M. fortuitum keratitis. Both clarithromycin and ciprofloxacin were better tolerated than combined amikacin and vancomycin. This study supports the further development of clarithromycin, a new macrolide antibiotic, as a topical drug for treatment of M. fortuitum keratitis.

A new approach to input device key design using fingerprints

A new approach to designing input device keys is proposed, and a TV remote controller is used as an example to demonstrate the new approach for studying the relationship between fingerprints and key geometry. One hundred subjects' fingerprints of thumbs and index fingers of both hands were collected, and a computer program was used for converting the fingerprint to a bitmap form. Subsequently, the data were analysed to provide some guidelines for determining the key size and key shape for the input device. Finally, the fingerprints were used to study the pattern of finger press and the justification for keycap curvature for finger placement. The results showed that the new approach can be useful in guiding designers of input device keys. A further benefit of this study is in providing a more systematic approach with considerable general potential for studying input device keys.

Measurement of vascular volume in experimental rat tumors by 19F magnetic resonance imaging

RATIONALE AND OBJECTIVES

In-vivo assessment of tumor vascular volume may provide useful information for treatment planning or the assessment of treatment effectiveness. The goals of our study were to measure percent vascular volume in two experimental tumor sublines using 19F magnetic resonance imaging (MRI) and to assess changes in tumor blood volume with growth.

METHODS

An emulsion of perfluorotributylamine (FTBA) was used as a vascular contrast agent for 19F MRI: The amount of emulsion in the tumor vasculature was measured by 19F MRI and used to calculate percent vascular volume. A separate ex-vivo study of vascular volume was conducted using the dye Hoechst 33342. A total of five rats were studied by MRI and 14 by the ex-vivo method.

RESULTS

The ranges of percent vascular volume values measured in the imaging and Hoechst dye studies were 2% to 9% and 1.25 to 7%, respectively. A trend toward decreasing percent vascular volume with increasing tumor volume was evident in one tumor subline.

CONCLUSIONS

The quantitative 19F MRI technique was effective for measuring percent vascular volume and changes in vascular volume with growth.

Alpha-interferon 2b in the treatment of chronic hepatitis C: interim report of the first multicentre Australian trial

Interferon has been shown to be effective in the treatment of chronic hepatitis C but the optimal treatment regime has not yet been defined. Studies using 3 million units (MU) of interferon thrice weekly (tiw) for 6 months have shown normalization of serum alanine aminotransferase (ALT) in about 50% of patients, but relapse occurs in at least 50% of responders after interferon is stopped. The aims of this study were to determine whether 5 MU of interferon tiw produces a higher response rate than 3 MU tiw and to examine if the higher dose results in more sustained remissions. In addition, factors that are associated with a more or less favourable response to interferon treatment were sought. Overall, 65% of patients responded and no advantage of the higher dose therapy was found, either in terms of response or relapse rate after treatment. The presence of cirrhosis on the pre-treatment liver biopsy was associated with a poor response rate to interferon and a trend towards a higher relapse rate. Risk factor for acquisition of disease was also related to likelihood of response but not relapse. We conclude that two thirds of Australian patients with chronic hepatitis C initially respond to interferon treatment. Positive predictors of response are intravenous drug use as a risk factor and histologically less severe liver disease. Relapse occurs in two thirds of all responders.

Molecular, functional, and evolutionary analysis of sequences specific to Salmonella

In that salmonellae have been implicated in an unprecedented array of diseases, sequences found to be specific to this species are often thought to be involved in the virulence attributes not seen in other enteric bacteria. To identify the molecular, genetic, and phenotypic characteristics that differentiate bacterial species, we analyzed five cloned DNA fragments that were originally described as being confined to Salmonella. Most of these segments mapped to unique positions on the Salmonella typhimurium chromosome indicative of independent evolutionary events, and three had G+C contents considerably lower than that of the Salmonella genome, suggesting that they arose through horizontal transfer. The nucleotide sequence was determined for one of the clones exhibiting an atypical base composition. This 4.9-kb fragment contained an open reading frame with structural similarity to the LysR family of transcriptional regulators. Strains harboring deletions in this region were tested for > 120 phenotypic characteristics including the effects on a collection of environmentally regulated lac gene fusions. In addition, all deletion strains behaved like the wild-type parent when tested for virulence in mice.

A comparison of single nucleotide primer extension with mispairing PCR-RFLP in detecting a point mutation

A recent report by Petruzzella et al. (BBRC 186, 491-497, 1992) raised a question as to whether a point mutation in the mitochondrial ND2 gene (BBRC 182, 238-246, 1992) is relevant to Alzheimer's disease. The argument was based on their inability to detect the point mutation at position 5460 in codon 331 in the DNAs extracted from 15 patients with Alzheimer's disease using mispairing PCR-RFLP. To clarify the discrepancy, we tested the DNAs reported by Petruzzella et al. for the mutation by single-nucleotide primer extension. The present work confirms our previous report and extends our finding of the point mutation in 8 of the 15 AD DNAs.

Hepatitis C as the cause of chronic non-A, non-B hepatitis: high sensitivity of simultaneous measurement of core and non-structural antibodies

First generation serologic tests (ELISA-1) for hepatitis C virus infection measure antibodies directed against a short non-structural segment of the virus (anti-c100-3). A major disadvantage of this test is that it lacks sensitivity in the identification of hepatitis C virus among patients at risk of infection. Thus, only 70-90% of chronic non-A, non-B cases are ELISA-1 positive. The present study set out to determine whether antibodies directed against the core region would be a more sensitive indicator of hepatitis C virus infection in patients with chronic non-A, non-B hepatitis. Sera were studied from 97 patients with raised serum alanine aminotransferase levels for more than 6 months in whom other causes of abnormal alanine aminotransferase were excluded. Using ELISA-1, 85 sera (87%) were anti-c100-3 positive. Sera were then tested for presence of antibody directed against Po, a core peptide of a Japanese strain of hepatitis C virus, using an ELISA method. Eighty-eight sera (91%) were anti-Po positive. Among the 12 anti-c100-3 negative patients, six were anti-Po positive. A second generation ELISA for anti-HCV (ELISA-2) incorporates a different antibody to the core region (c22-3) in addition to an expanded non-structural region, c200, which consists of c100-3 plus c33c. With these tests, all sera but one were positive, including 11 of 12 ELISA-1 negative and eight of nine anti-Po negative sera.(ABSTRACT TRUNCATED AT 250 WORDS)

Highly acetylated H4 is associated with histone displacement in rat spermatids

The presence of highly acetylated histone H4 during spermatogenesis was studied to evaluate its correlation with the events of gene transcription, histone deposition, and histone displacement. We utilized an antibody raised to a pentaacetylated synthetic peptide that preferentially recognizes highly (tetra- and tri-) acetylated forms of rat testis H4. Electrophoretic separation of histones from enriched fractions of spermatogenic cells followed by detection of these forms by staining and by immunoblotting using this antibody showed that the highly acetylated forms were limited almost exclusively to spermatids beginning at step 11 of development. Immunoflurescence also revealed a striking polarity in the progression of histone from the spermatid nucleus. Highly acetylated H4 was displaced from the anterior to the caudal portion of the spermatid nucleus during steps 11 and 12, along with other histones, prior to their displacement by transition proteins. Thus, while monoacetylated and low levels of diacetylated forms of H4 were associated with stages at which histone deposition and transcription occur, the more highly acetylated forms appeared in high levels only at the stage at which histone displacement occurs.

The lrp gene product regulates expression of lysU in Escherichia coli K-12

In Escherichia coli K-12, expression of the lysU gene is regulated by the lrp gene product, as indicated by an increase in the level of lysyl-tRNA synthetase activity and LysU protein in an lrp mutant. Comparison of the patterns of protein expression visualized by two-dimensional gel electrophoresis indicated that LysU is present at higher levels in an lrp strain than in its isogenic lrp+ parent. The purified lrp gene product was shown to bind to sites upstream of the lysU gene and to protect several sites against DNase I digestion. A region extending over 100 nucleotides, between 60 and 160 nucleotides upstream from the start of the lysU coding sequence, showed altered sensitivity to DNase I digestion in the presence of the Lrp protein. The extent of protected DNA suggests a complex interaction of Lrp protein and upstream lysU DNA.

Lambda placMu insertions in genes of the leucine regulon: extension of the regulon to genes not regulated by leucine

The leucine regulon coordinates the expression of several Escherichia coli genes according to the presence of exogenous leucine, which interacts with the lrp gene product, Lrp. We isolated and characterized 22 strains with lambda placMu insertions in Lrp-regulated genes. Lrp and leucine influenced gene expression in a surprising variety of ways. We identified two genes that are regulated by Lrp and not affected by L-leucine. We therefore rename this the leucine-lrp regulon. Genes coding for glycine cleavage and leucine biosynthesis enzymes have been identified as members of the leucine-lrp regulon. We suggest that the lrp gene product activates genes needed for growth in minimal medium, and we show that the gene is repressed by its own product and is highly repressed during growth in rich medium.

Detection of point mutations in codon 331 of mitochondrial NADH dehydrogenase subunit 2 in alzheimer's brains

Point mutations in codon 331 of mitochondrial NADH dehydrogenase subunit 2 (ND2) were detected in 10 of 19 Alzheimer's brains but not in 11 normal brains. The same mutations were also detected in 2 of 6 patients with amyotrophic lateral sclerosis (ALS). However, neurofibrillary tangles and neuritic plaques characteristic of Alzheimer's disease were found histologically in the brain of one ALS patient who was positive of the mutation. The finding suggests that a point mutation in ND2 is a potential risk factor for Alzheimer's disease.

A history-taking system that uses continuous speech recognition

Q-MED is an automated history-taking system that uses speaker-independent continuous speech as its main interface modality. Q-MED is designed to allow a patient to enter her basic symptoms by engaging in a dialog with the program. Error-recovery mechanisms help to eliminate findings resulting from misrecognitions or incorrect parses. An evaluation of the natural language parser that Q-MED uses to map user utterances to findings showed an overall semantic accuracy of 87 percent; Q-MED asks more specific questions to capture findings that were not volunteered, or that were unable to be parsed in their initial, open-ended form.

Proteolytic removal of core histone amino termini and dephosphorylation of histone H1 correlate with the formation of condensed chromatin and transcriptional silencing during Tetrahymena macronuclear development

During the sexual cycle in Tetrahymena, the germ-line micronucleus gives rise to new macro- and micronuclei, whereas the former somatic macronucleus ceases transcription, becomes highly condensed, and is eventually eliminated from the cell. With polyclonal antibodies specific for acetylated forms of histone H4, immunofluorescent analyses have demonstrated that transcriptionally active macronuclei stain positively at all stages of the life cycle except during conjugation, when parental macronuclei become inactive and are eliminated from the cell. In this report using affinity-purified antibodies to either the acetylated or unacetylated amino-terminal domain of H4, immunofluorescent analyses suggest that the acetylated amino-terminal tails of H4 are proteolytically removed in "old" macronuclei during this period. This suggestion was further confirmed by biochemical analysis of purified old macronuclei that revealed several polypeptides with molecular mass 1-2 kD less than that of intact core histones. These species, which are unique to old macronuclei, are not newly synthesized and fail to stain with either acetylated or unacetylated H4 antibodies. Microsequence analysis clearly shows that these polypeptides are proteolytically processed forms of core histones whose amino-terminal "tails" (varying from 13 to 21 residues) have been removed. During the same developmental period, histone H1 is dephosphorylated rapidly and completely in old macronuclei. These results strongly suggest that the developmentally regulated proteolysis of core histones and dephosphorylation of histone H1 participate in a novel pathway leading to the formation of highly condensed chromatin and transcriptional silencing during Tetrahymena macronuclear development.

Prediction of response to interferon in patients with chronic active hepatitis C, and evidence that this improves hepatic metabolic function

We sought to ascertain whether response to alpha interferon treatment could be predicted among patients with chronic active hepatitis C, and whether antipyrine clearance estimations would determine changes in liver function with this disease. The patients came from a randomized controlled trial, with patients who were initially untreated eventually being offered interferon treatment. Among 28 patients treated with interferon 18 (64%) responded with normalization of serum aminotransferase levels. Responders were less likely to have acquired hepatitis C by blood transfusion and more likely to have acquired it by intravenous drug abuse (P less than 0.05). All 13 patients with less severe chronic active hepatitis responded to interferon but only 5 of 15 patients with progressive fibrosis or cirrhosis responded (P less than 0.01). During 8-39 (median 19) months of observation of 16 untreated patients, there was a significant fall in antipyrine clearance (Cl-Ap) but no change in serum albumin. Among interferon-treated patients, Cl-Ap improved in 9 of 16 compared with 1 of 14 controls observed for the same time period (P less than 0.02). It is concluded that Cl-Ap is a sensitive test for detecting changes in liver function during chronic hepatitis. Without treatment, deterioration is evident at 18 months in 50% of patients with chronic active hepatitis C. Conversely, normalization of serum aminotransferase levels by interferon is associated with improvement of Cl-Ap.(ABSTRACT TRUNCATED AT 250 WORDS)

Can the response to interferon treatment be predicted in patients with chronic active hepatitis C?

Twenty-one of 40 patients with chronic non-A, non-B hepatitis (37 anti-HCV positive) were randomised to receive interferon alpha 2b (3 million units subcutaneously thrice weekly for 24 weeks) and then to be observed for six months. Among the other 19 patients (controls) randomised to be observed without treatment for 12 months, eight have subsequently been treated with interferon for six months. One treated patient and three controls were lost to follow-up. A return to normal serum alanine aminotransferase levels which lasted until the end of the treatment period occurred in 18 (64%) of the 28 patients given interferon (and in 13 of 21 (62%) randomised to treatment), but only in one of the 16 untreated controls (p less than 0.001). Multivariant analysis indicated that, compared with the ten nonresponders, the 18 patients who responded to interferon were more likely to have acquired infection by intravenous drug abuse than by blood transfusion (p less than 0.05), and were more likely to have histologically less severe chronic liver disease (p less than 0.01). Thus, all 13 patients with less severe liver disease histologically responded to interferon, but only five of 15 patients with cirrhosis or bridging fibrosis responded. Among 17 responders followed for more than four months, five (28%) are still in remission a median of 13 months (range four months to 24 months) after stopping interferon. The characteristics which favoured a response during treatment also appeared to distinguish those who experienced sustained post-treatment remission.(ABSTRACT TRUNCATED AT 250 WORDS)

Timing of the appearance of ubiquitinated histones in developing new macronuclei of Tetrahymena thermophila

Vegetative cells of the ciliated protozoan Tetrahymena thermophila contain a transcriptionally active macronucleus and a transcriptionally inert micronucleus. During vegetative growth, macronuclear histones H2A and H2B and micronuclear H2A are ubiquitinated. Despite differences in function, macro- and micro-nuclei are related. During conjugation (the sexual phase of the life cycle in Tetrahymena), postzygotic division products of micronuclei give rise to new micro- and macro-nuclei. Using an anti-ubiquitin antibody in Western blotting experiments, we determined the levels of ubiquitinated histones in new macro- and micro-nuclei at various times during conjugation. Very soon after the second postzygotic division (approximately 8 h) when new macronuclei begin to synthesize RNA, ubiquitinated H2B and polyubiquitinated H2A are present. At this time micronuclei have only low levels of ubiquitinated H2A. During later stages of conjugation (15 h), the level of polyubiquitinated H2A decreases, while ubiquitinated H2B increases in developing new macronuclei, attaining levels of ubiquitinated H2B approaching that of parental macronuclei. Ubiquitinated histones are not detectable in the 15-h micronuclei. These results show that ubiquitination of H2B coincides with the transformation of an inert germinal nucleus into that of a transcriptionally active somatic nucleus, suggesting that ubiquitinated H2B has a role in maintaining the transcriptionally active chromatin state.

A free-text processing system to capture physical findings: Canonical Phrase Identification System (CAPIS)

The task of gathering detailed patient information from free-text medical records presents a significant barrier to clinical research. In this paper, we describe a prototype system for extracting physical examination findings from dictated admission summaries. Our computer program applies a concept-based free-text processing algorithm that identifies user-selected target physical examination findings. We are using the extraction system to enrich an existing clinical database. The system was evaluated by comparing the physical examination findings extracted by our computer program with findings extracted by an independent investigator. Our prototype system was able to recall 92 percent (sensitivity) of the relevant physical findings, with a precision of 96 percent (positive predictive value).

A free-text processing system to capture physical findings: Canonical Phrase Identification System (CAPIS)

The task of gathering detailed patient information from free-text medical records presents a significant barrier to clinical research. In this paper, we describe a prototype system for extracting physical examination findings from dictated admission summaries. Our computer program applies a concept-based free-text processing algorithm that identifies user-selected target physical examination findings. We are using the extraction system to enrich an existing clinical database. The system was evaluated by comparing the physical examination findings extracted by our computer program with findings extracted by an independent investigator. Our prototype system was able to recall 92 percent (sensitivity) of the relevant physical findings, with a precision of 96 percent (positive predictive value).

The role of fibre optics in gastroenterology

Diagnostic fibre optic endoscopy has a well established role in clinical gastroenterology. The authors highlight the expanding therapeutic applications of this technology.

Delayed onset PTSD among Israeli veterans of the 1982 Lebanon War

This is an exploratory study of the nature, course and rates of delayed post-traumatic stress disorder (PTSD). We reviewed 150 medical files of Israeli soldiers who sought help between 6 months and 5 years after the 1982 Lebanon War. Results indicated that only 10% of the cases were truly examples of delayed PTSD; in a large proportion of the cases, help-seeking rather than onset was delayed.

Antibodies specific to acetylated histones document the existence of deposition- and transcription-related histone acetylation in Tetrahymena

In this study, we have constructed synthetic peptides which are identical to hyperacetylated amino termini of two Tetrahymena core histones (tetra-acetylated H4 and penta-acetylated hv1) and used them to generate polyclonal antibodies specific for acetylated forms (mono-, di-, tri-, etc.) of these histones. Neither of these antisera recognizes histone that is unacetylated. Immunoblotting analyses demonstrate that both transcription-related and deposition-related acetate groups on H4 are recognized by both antisera. In addition, the antiserum raised against penta-acetylated hv1 also recognizes acetylated forms of this variant. Immunofluorescent analyses with both antisera demonstrate that, as expected, histone acetylation is specific to macronuclei (or new macronuclei) at all stages of the life cycle except when micronuclei undergo periods of rapid replication and chromatin assembly. During this time micronuclear staining is also detected. Our results also suggest that transcription-related acetylation begins selectively in new macronuclei immediately after the second postzygotic division. Acetylated histone is not observed in new micronuclei during stages corresponding to anlagen development and, therefore, histone acetylation can be distributed asymmetrically in development. Equally striking is the rapid turnover of acetylated histone in parental macronuclei during the time of their inactivation and elimination from the cell. Taken together, these data lend strong support to the idea that modulation of histone acetylation plays an important role in gene activation and in chromatin assembly.

Lipoprotein lipase: a source of free fatty acids in bronchoalveolar lining fluid

Long-chain free fatty acids (FFAs) in pulmonary bronchoalveolar lavage fluid (BALF) are antimicrobial agents that may participate in lung defenses. FFAs may also participate in synthetic and metabolic activities of bronchoalveolar lining cells. In evaluating the origins of FFAs, we found that rat triglyceride lipase activity was readily detectable in rat BALF. This activity appeared to be caused mainly by lipoprotein lipase (LPL), because it was inhibited by protamine, a high salt concentration, or specific anti-LPL antibody. LPL activity was detected in BALF from guinea pigs, humans, and rabbits, but rats had significantly more LPL activity than the other species. LPL activity in rat BALF was enhanced by heat-inactivated serum, but LPL-mediated hydrolysis of triglycerides in BALF proceeded at 37 degrees C in vitro even without serum. The possibility that BALF contained an intrinsic LPL activating factor(s) was suggested by the fact that concentrated, heat-inactivated lavage was 85% as effective as heat-inactivated serum in enhancing the LPL activity of fresh BALF. Macrophages are the likely source of LPL in BALF, and we confirmed that rat resident alveolar macrophages produce LPL in culture in a time-dependent fashion. It was concluded that FFAs in BALF were produced by the hydrolysis of triglycerides by LPL.

Effect of diclofenac sodium (Voltaren) on spermatogenesis of infertile oligospermic patients

The effect of the prostaglandin synthesis inhibitor diclofenac sodium (Voltaren) on spermatogenesis in infertile oligospermic patients has been studied. Diclofenac sodium was given orally at a daily dose of 100 mg for 30 days. Seminal fluid parameters were evaluated. Group II with high levels of seminal prostaglandin showed a statistically significant increase in the number and motility of spermatozoa (p less than 0.01), whilst no significant variations were observed in patients of group I with normal values of seminal prostaglandin.

Deaths as a result of a combination of codeine and glutethimide

Toxicological findings are described in 16 medical examiner cases directly related to the combination of codeine and glutethimide. The cases described represent a six-month period, July through December 1982, showing the epidemic rate of abuse of this drug combination, most prominent in the Newark, NJ area since the late 1970s. Concentrations of codeine and glutethimide, measured by gas liquid chromatography (GLC), in the blood averaged 0.62 and 4.07 mg/L, respectively. Similarly determined urine concentrations averaged 38.06 and 12.68 mg/L, respectively. Specific concentrations of each drug in most cases were in the high therapeutic range, suggesting a possible toxic synergistic effect.

Effects of antibiotics on polymorphonuclear leukocyte chemiluminescence and chemotaxis

Polymorphonuclear leukocyte chemiluminescence and chemotaxis assays were performed on cells obtained from normal individuals and patients with defined defects in chemotaxis or chemiluminescence. After in-vitro pre-incubation with trimethoprim/sulphamethoxazole, its separate components, clindamycin and cefotaxime, normal cells showed some enhancement in chemotaxis and significant increase in chemiluminescence. There was an even more marked increase in chemotaxis when these antibiotics were incubated with cells from patients with leukocyte chemotaxic defects. When the cells from patients with chemiluminescence defects were pre-incubated with these antibiotics, there was also substantial enhancement in chemiluminescence.

Histo-mechanical aspects of carpal tunnel syndrome

Carpal tunnel syndrome is a result of median nerve compression within the carpal canal. Factors associated with the appearance of carpal tunnel syndrome can be related to the bony architecture of the carpal canal, to its contents and to systemic disease. The purpose of this work is to see if changes in the elasticity of the transverse carpal ligament may cause carpal tunnel syndrome.

Value of concomitant sympathectomy in aortoiliac reconstruction. Results of a prospective, randomized study

The efficacy of concomitant lumbar sympathectomy in improving results of aortoiliac reconstruction was assessed by a prospective, randomized study of 51 patients undergoing operation for occlusive or aneurysmal disease. Sympathectomy was performed on 50 limbs, while 52 extremities served as controls. Sympathectomy resulted in a significant reduction in foot vascular resistance determined by plethysmography. However, the procedure had no effect on leg circulation, assessed by ankle/arm pressure indices determined by Doppler ultrasound. In the sympathectomy group, there were three early postoperative amputations for ischemia, despite patent grafts. In the control group, there was one late graft occlusion, caused by progressive atherosclerotic disease. Although sympathectomy may improve pedal circulation, the procedure does not appear to improve the results of aortoiliac reconstruction.