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.