The cytotoxic T lymphocyte response to multiple hepatitis B virus polymerase epitopes during and after acute viral hepatitis

Cytotoxic T lymphocytes (CTL) are thought to contribute to viral clearance and liver cell injury during hepatitis B virus (HBV) infection. Using a strategy involving the in vitro stimulation of peripheral blood mononuclear cells (PBMC) with HBV-derived synthetic peptides containing HLA-A2.1, -A31, and -Aw68 binding motifs, we have previously described CTL responses to several epitopes within the HBV nucleocapsid and envelope antigens in patients with acute hepatitis. In this study we define six HLA-A2-restricted CTL epitopes located in the highly conserved reverse transcriptase and RNase H domains of the viral polymerase protein, and we show that the CTL response to polymerase is polyclonal, multispecific, and mediated by CD8+ T cells in patients with acute viral hepatitis, but that it is not detectable in patients with chronic HBV infection or uninfected healthy blood donors. Importantly, the peptide-activated CTL recognize target cells that express endogenously synthesized polymerase protein, suggesting that these peptides represent naturally processed viral epitopes. DNA sequence analysis of the viruses in patients who did not respond to peptide stimulation indicated that CTL nonresponsiveness was not due to infection by viral variants that differed in sequences from the synthetic peptides. CTL specific for one of the epitopes were unable to recognize several naturally occurring viral variants, except at high peptide concentration, underlining the HBV subtype specificity of this response. Furthermore, CTL responses against polymerase, core, and envelope epitopes were detectable for more than a year after complete clinical recovery and seroconversion, reflecting either the persistence of trace amounts of virus or the presence of long lived memory CTL in the absence of viral antigen. Finally, we demonstrated that wild type viral DNA and RNA can persist indefinitely, in trace quantities, in the serum and PBMC after complete clinical and serological recovery, despite a concomitant, vigorous, and sustained polyclonal CTL response. Since viral persistence is not due to escape from CTL recognition under these conditions, the data suggest that HBV may retreat into immunologically privileged sites from which it can seed the circulation and reach CTL-inaccessible tissues, thereby maintaining the CTL response in apparently cured individuals and, perhaps, prolonging the liver disease in patients with chronic hepatitis.

Circulating leptin in women: a longitudinal study in the menstrual cycle and during pregnancy

OBJECTIVE

To investigate whether leptin is linked to reproduction, circulating levels were measured longitudinally throughout spontaneous menstrual cycles and during pregnancy in normal women.

DESIGN

Longitudinal blood samples were collected from normal volunteers, either during regular menstrual cycles or during successful singleton pregnancies.

PATIENTS

Six healthy, regularly cycling, women volunteers (31.5 +/- 3.0 years old, BMI = 21.6 +/- 0.5) were recruited for serial venous blood sampling throughout one complete menstrual cycle. In addition, five healthy, women (31.8 +/- 1.2 years old, pregnant BMI = 30.0 +/- 3.1) provided serial venous blood samples throughout one complete singleton pregnancy.

MEASUREMENTS

Circulating venous oestradiol, progesterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), leptin and (pregnant group only) human chorionic gonadotrophin (hCG).

RESULTS

In spontaneously cycling women, changes in circulating leptin levels were associated with menstrual phase (P < 0.001) and correlated with progesterone levels (P < 0.05). Peak leptin concentrations were recorded during the luteal phase (P < 0.01), coincident with maximal progesterone levels (P < 0.05). Leptin concentrations were elevated throughout gestation (P < 0.05), and especially during the second trimester (P < 0.05). Post-partum, circulating leptin levels fell sharply to below pregnant values. Leptin correlated with oestradiol (P < 0.05) and human chorionic gonadotrophin (hCG, P < 0.01) levels during pregnancy. First trimester (P < 0.05) and postpartum (P < 0.05) oestradiol concentrations and post-partum hCG levels exhibited the greatest correlation with circulating leptin.

CONCLUSIONS

We conclude that the relationship between body mass index and circulating leptin varies during the course of spontaneous cycles in women, the best correlation occurring during the luteal phase when progesterone and leptin concentrations are highest. This, together with the correlation between circulating oestradiol, hCG and leptin levels during pregnancy, strongly suggests a dynamic relationship between leptin and reproductive events in women.

Cytotoxic T lymphocytes recognize an HLA-A2-restricted epitope within the hepatitis B virus nucleocapsid antigen

The absence of readily manipulable experimental systems to study the cytotoxic T lymphocyte (CTL) response against hepatitis B virus (HBV) antigens has thus far precluded a definitive demonstration of the role played by this response in the pathogenesis of liver cell injury and viral clearance during HBV infection. To circumvent the problem that HBV infection of human cells in vitro for production of stimulator/target systems for CTL analysis is not feasible, a panel of 22 overlapping synthetic peptides covering the entire amino acid sequence of the HBV core (HBcAg) and e (HBeAg) antigens were used to induce and to analyze the HBV nucleocapsid-specific CTL response in nine patients with acute hepatitis B, six patients with chronic active hepatitis B, and eight normal controls. By using this approach, we have identified an HLA-A2-restricted CTL epitope, located within the NH2-terminal region of the HBV core molecule, which is shared with the e antigen and is readily recognized by peripheral blood mononuclear cells from patients with self-limited acute hepatitis B but less efficiently in chronic HBV infection. Our study provides the first direct evidence of HLA class I-restricted T cell cytotoxicity against HBV in humans. Furthermore, the different response in HBV-infected subjects who successfully clear the virus (acute patients) in comparison with patients who do not succeed (chronic patients) suggests a pathogenetic role for this CTL activity in the clearance of HBV infection.

Immune pathogenesis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common complication of chronic hepatitis B virus (HBV) infection. The pathogenetic mechanisms potentially responsible for HCC during chronic HBV infection are not well defined. This study demonstrates that chronic immune-mediated liver cell injury triggers the development of HCC in the absence of viral transactivation, insertional mutagenesis, and genotoxic chemicals. These results strongly suggest that the immune response to HBV is both necessary and sufficient to cause liver cancer during chronic HBV infection, and that all other procarcinogenic events associated with HCC are probably dependent on this process.

Cytotoxic T lymphocyte response to hepatitis C virus-derived peptides containing the HLA A2.1 binding motif

The HLA class I-restricted cytotoxic T lymphocyte (CTL) response is a major defense mechanism in viral infections. It has been suggested that the CTL response may contribute to viral clearance and liver cell injury during hepatitis C virus (HCV) infection. To test this hypothesis requires an understanding of the characteristics of HCV-specific cytotoxic effector cells and identification of the target antigens to which they respond. To begin this process we stimulated peripheral blood mononuclear cells (PBMC) from a group of HLA-A2 positive patients with chronic hepatitis C with a panel of 130 HCV-derived peptides containing the HLA-A2 binding motif. Effector cells were tested for their capacity to lyse HLA-A2-matched target cells that were either sensitized with peptide or infected with a vaccinia virus construct containing HCV sequences. Using this approach we have identified nine immunogenic peptides in HCV, three of which are derived from the putative core protein, three from the nonstructural (NS) 3 domain, two from NS4 and one from NS5. Selected responses were shown to be HLA-A2 restricted, mediated by CD8+ T cells and to recognize endogenously synthesized viral antigen. Unexpectedly, peptide-specific CTL responses could also be induced in sero-negative individuals, suggesting in vitro activation of naive CTL precursors. The precursor frequency of peptide-specific CTL was 10 to 100-fold higher in infected patients compared to uninfected controls, and the responses were greatly diminished by removal of CD45 RO+ (memory) T cells. Further quantitative studies are clearly required to establish whether a correlation exists between the HCV-specific CTL response and the clinical course of this disease. Definition of the molecular targets of the human CTL response to HCV creates this opportunity, and may also contribute to the development of a T cell-based HCV vaccine.

Characteristics of degraded cellulose obtained from steam-exploded wheat straw

The isolation of cellulose from wheat straw was studied using a two-stage process based on steam explosion pre-treatment followed by alkaline peroxide post-treatment. Straw was steamed at 200 degrees C, 15 bar for 10 and 33 min, and 220 degrees C, 22 bar for 3, 5 and 8 min with a solid to liquid ratio of 2:1 (w/w) and 220 degrees C, 22 bar for 5 min with a solid to liquid ratio of 10:1, respectively. The steamed straw was washed with hot water to yield a solution rich in hemicelluloses-derived mono- and oligosaccharides and gave 61.3%, 60.2%, 66.2%, 63.1%, 60.3% and 61.3% of the straw residue, respectively. The washed fibre was delignified and bleached by 2% H2O2 at 50 degrees C for 5 h under pH 11.5, which yielded 34.9%, 32.6%, 40.0%, 36.9%, 30.9% and 36.1% (% dry wheat straw) of the cellulose preparation, respectively. The optimum cellulose yield (40.0%) was obtained when the steam explosion pre-treatment was performed at 220 degrees C, 22 bar for 3 min with a solid to liquid ratio of 2:1, in which the cellulose fraction obtained had a viscosity average degree of polymerisation of 587 and contained 14.6% hemicelluloses and 1.2% klason lignin. The steam explosion pre-treatment led to a significant loss in hemicelluloses and alkaline peroxide post-treatment resulted in substantial dissolution of lignin and an increase in cellulose crystallinity. The six isolated cellulose samples were further characterised by FT-IR and 13C-CP/MAS NMR spectroscopy and thermal analysis.

Extensive oxidative DNA damage in hepatocytes of transgenic mice with chronic active hepatitis destined to develop hepatocellular carcinoma

A transgenic mouse strain that expresses the hepatitis B virus (HBV) large envelope protein in the liver was used to determine the extent of oxidative DNA damage that occurs during chronic HBV infection. This mouse strain develops a chronic necroinflammatory liver disease that mimics the inflammation, cellular hyperplasia, and increased risk for cancer that is evident in human chronic active hepatitis. When perfused in situ with nitroblue tetrazolium, an indicator for superoxide formation, the liver of transgenic mice displayed intense formazan deposition in Kupffer cells, indicating oxygen radical production, and S-phase hepatocytes were commonly seen adjacent to the stained Kupffer cells. Similar changes were not observed in nontransgenic control livers. To determine whether these events were associated with oxidative DNA damage, genomic DNA from the livers of transgenic mice and nontransgenic controls was isolated and examined for 8-oxo-2'-deoxyguanosine, an oxidatively modified adduct of deoxyguanosine. Results showed a significant, sustained accumulation in steady-state 8-oxo-2'-deoxyguanosine that started early in life exclusively in the transgenic mice and increased progressively with advancing disease. The most pronounced increase occurred in livers exhibiting microscopic nodular hyperplasia, adenomas, and hepatocellular carcinoma. Thus, HBV transgenic mice with chronic active hepatitis display greatly increased hepatic oxidative DNA damage. Moreover, the DNA damage occurs in the presence of heightened hepatocellular proliferation, increasing the probability of fixation of the attendant genetic and chromosomal abnormalities and the development of hepatocellular carcinoma.

HLA class I-restricted human cytotoxic T cells recognize endogenously synthesized hepatitis B virus nucleocapsid antigen

Knowledge of the immune effector mechanisms responsible for clearance of hepatitis B virus (HBV)-infected cells has been severely limited by the absence of reproducible systems to selectively expand and to characterize HBV-specific cytotoxic T lymphocytes (CTLs) in the peripheral blood of patients with viral hepatitis. By using a strategy involving sequential stimulation with HBV nucleocapsid synthetic peptides followed by autologous, or HLA class I-matched, HBV nucleocapsid transfectants, we now report the existence of CTLs able to lyse target cells that express endogenously synthesized HBV nucleocapsid antigen in the peripheral blood of patients with acute viral hepatitis B. The CTL response is HLA-A2 restricted, mediated by CD8-positive T cells, and specific for a single epitope, located between amino acid residues 11 and 27 of HBV core protein; these residues are shared with the secretable precore-derived hepatitis B e antigen. Equivalent lysis of target cells that express each of these proteins suggests that their intracellular trafficking pathways may intersect. The current report provides definitive evidence that HLA class I-restricted, CD8-positive CTLs that recognize endogenously synthesized HBV nucleocapsid antigen are induced during acute HBV infection in humans and establishes a strategy that should permit a detailed analysis of the role played by HBV-specific CTLs in the immunopathogenesis of viral hepatitis.

The effect of bracing on varus gonarthrosis

BACKGROUND

The purpose of this study was to compare a custom-made valgus-producing functional knee (unloader) brace, a neoprene sleeve, and medical treatment only (control group) with regard to their ability to improve the disease-specific quality of life and the functional status of patients who had osteoarthritis in association with a varus deformity of the knee (varus gonarthrosis).

METHODS

The study design was a prospective, parallel-group, randomized clinical trial. Patients who had varus gonarthrosis were screened for eligibility. The criteria for exclusion included arthritides other than osteoarthritis; an operation on the knee within the previous six months; symptomatic disease of the hip, ankle, or foot; a previous fracture of the tibia or femur; morbid obesity (a body-mass index of more than thirty-five kilograms per square meter); skin disease; peripheral vascular disease or varicose veins that would preclude use of a brace; a severe cardiovascular deficit; blindness; poor English-language skills; and an inability to apply a brace because of physical limitations such as arthritis in the hand or an inability to bend over. Treatment was assigned on the basis of a computer-generated block method of randomization with use of sealed envelopes. The patients were stratified according to age (less than fifty years or at least fifty years), deformity (the mechanical axis in less than 5 degrees of varus or in at least 5 degrees of varus), and the status of the anterior cruciate ligament (torn or intact). The patients were randomly assigned to one of three treatment groups: medical treatment only (control group), medical treatment and use of a neoprene sleeve, or medical treatment and use of an unloader brace. The disease-specific quality of life was measured with use of the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and the McMaster-Toronto Arthritis Patient Preference Disability Questionnaire (MACTAR), and function was assessed with use of the six-minute walking and thirty-second stair-climbing tests. The primary outcome measure consisted of an analysis of covariance of the change in scores between the baseline and six-month evaluations.

RESULTS

One hundred and nineteen patients were randomized. The control group consisted of forty patients (thirty-one men and nine women; mean age, 60.9 years); the neoprene-sleeve group, of thirty-eight patients (twenty-seven men and eleven women; mean age, 58.2 years); and the unloader-brace group, of forty-one patients (twenty-eight men and thirteen women; mean age, 59.5 years). Nine patients withdrew from the study. At the six-month follow-up evaluation, there was a significant improvement in the disease-specific quality of life (p = 0.001) and in function (p< or =0.001) in both the neoprene-sleeve group and the unloader-brace group compared with the control group. There was a significant difference between the unloader-brace group and the neoprene-sleeve group with regard to pain after both the six-minute walking test (p = 0.021) and the thirty-second stair-climbing test (p = 0.016). There was a strong trend toward a significant difference between the unloader-brace group and the neoprene-sleeve group with regard to the change in the WOMAC aggregate (p = 0.062) and WOMAC physical function scores (p = 0.081).

CONCLUSIONS

The results indicate that patients who have varus gonarthrosis may benefit significantly from use of a knee brace in addition to standard medical treatment. The unloader brace was, on the average, more effective than the neoprene sleeve. The ideal candidates for each of these bracing options remain to be identified.

HLA-A31- and HLA-Aw68-restricted cytotoxic T cell responses to a single hepatitis B virus nucleocapsid epitope during acute viral hepatitis

We have recently developed the technology to identify and characterize the human histocompatibility leukocyte antigen (HLA) class I-restricted, CD8+ cytotoxic T lymphocyte (CTL) response to hepatitis B virus (HBV)-encoded antigens in patients with acute viral hepatitis. CTL are expanded in vitro by stimulation with HBV-derived synthetic peptides and selected by restimulation with a panel of HLA-matched stable transfectants that express the corresponding HBV protein. We have recently reported the existence of an HLA-A2-restricted, CD8+ CTL response to an epitope located between residues 18 and 27 of the HBV nucleocapsid core antigen (HBcAg). We now report the discovery of a CTL epitope located between HBcAg residues 141 and 151 that completely overlaps a critical domain in the viral nucleocapsid protein that is essential for its nuclear localization and genome packaging functions as well as processing of the precore protein. The CTL response to this epitope is dually restricted by the HLA-A31 and HLA-Aw68 alleles, which, unexpectedly, appear to use a common binding motif based on the results of alanine substitution and competition analysis, and the binding properties of these two alleles predicted from their known primary sequence, and from the three-dimensional structure of HLA-Aw68. We have also demonstrated that the HBV-specific CTL response to this epitope is polyclonal during acute viral hepatitis, since these two restriction elements can present the HBcAg 141-151 epitope to independent CTL clones derived from a single patient; and that the CTL response is multispecific, since HLA-A2-restricted and HLA-Aw68-restricted CTL responses to HBcAg 18-27 and HBcAg 141-151, respectively, have been identified to coexist in another patient. The foregoing argue against the emergence of CTL escape mutants as a significant problem during HBV infection, especially at this locus, where mutations might be incompatible with viral replication. Finally, our data suggest an association between the HBV-specific CTL response and viral clearance, and they have implications for the design of immunotherapeutic strategies to terminate HBV infection in chronically infected patients.

Identification of immunodominant T cell epitopes of the hepatitis B virus nucleocapsid antigen

Several lines of experimental evidence suggest that inclusion of core sequences in the hepatitis B vaccine may represent a feasible strategy to increase the efficacy of the vaccination. In order to identify immunodominant core epitopes, peripheral blood T cells purified from 23 patients with acute hepatitis B and different HLA haplotypes were tested with a panel of 18 short synthetic peptides (15 to 20 amino acids [AA]) covering the entire core region. All patients except one showed a strong T cell proliferative response to a single immunodominant 20 amino acid sequence located within the aminoterminal half of the core molecule. Two additional important sequences were also identified at the aminoterminal end and within the carboxyterminal half of the core molecule. These sequences were able to induce significant levels of T cell proliferation in 69 and 73% of the patients studied, respectively. T cell response to these epitopes was HLA class II restricted. The observations that (a) polyclonal T cell lines produced by PBMC stimulation with native HBcAg were specifically reactive with the relevant peptides and that (b) polyclonal T cell lines produced with synthetic peptides could be restimulated with native HBcAg, provide evidence that AA sequences contained within the synthetic peptides represent real products of the intracellular processing of the native core molecule. In conclusion, the identification of immunodominant T cell epitopes within the core molecule provides the molecular basis for the design of alternative and hopefully more immunogenic vaccines.

Definition of a minimal optimal cytotoxic T-cell epitope within the hepatitis B virus nucleocapsid protein

Residues 11 to 27 of the hepatitis B virus nucleocapsid antigen contain a cytotoxic T-cell epitope that is recognized by cytotoxic T cells from virtually all HLA-A2-positive patients with acute hepatitis B virus infection. Using panels of truncated and overlapping peptides, we now show that the optimal amino acid sequence recognized by cytotoxic T cells is a 10-mer (residues 18 to 27) containing the predicted peptide-binding motif for HLA-A2 and that this peptide can stimulate cytotoxic T cells able to recognize endogenously synthesized hepatitis B core antigen. Since patients with chronic hepatitis B virus infection fail to mount an efficient cytotoxic T-cell response to it, this epitope might serve as the starting point for the design of synthetic peptide-based immunotherapeutic strategies to terminate persistent viral infection.

Human histocompatibility leukocyte antigen-binding supermotifs predict broadly cross-reactive cytotoxic T lymphocyte responses in patients with acute hepatitis

The present study was designed to determine if highly conserved hepatitis B virus (HBV)-derived peptides that bind multiple HLA class I alleles with high affinity are recognized as cytotoxic T lymphocyte (CTL) epitopes in acutely infected patients. Peripheral blood mononuclear cells from 67 patients with acute hepatitis B, and 12 patients convalescent from acute hepatitis B, were stimulated with three panels of peptides, each of which bind with high affinity to several class I alleles from the HLA-A2-, HLA-A3-, or HLA-B7-supertypes. In these patients, 8 of the 19 peptides tested were found to represent CTL epitopes recognized by two or more alleles in each supertype. Two sets of nested peptides were recognized in the context of alleles with completely unrelated peptide binding specificities. Finally, promiscuous recognition by the same CTL of a given peptide presented by target cells expressing different A2 subtypes was also commonly observed. In conclusion, several HBV-specific CTL epitopes, recognized by acutely infected or convalescent patients in the context of a wide range of HLA alleles have been identified. These results demonstrate the functional relevance of the supertype grouping of HLA class I molecules in a human viral disease setting. Furthermore, they represent a significant advance in the development of a totally synthetic vaccine to terminate chronic HBV infection and support the feasibility of a systematic approach to development of similar vaccines for prevention and treatment of other chronic viral infections.

Physicochemical characterization of cellulose from perennial ryegrass leaves (Lolium perenne)

In this study, we investigated the physicochemical properties of the cellulosic preparations obtained from both untreated perennial ryegrass leaves and de-juiced leaves. It was found that treatment at 22 degrees C with 18% NaOH and 18% KOH for 2h, and 10% NaOH and 10% KOH for 16 h yielded 28.2%, 28.8%, 22.7%, 23.4%, respectively, of 'cellulose' residue from untreated ryegrass leaves and 35.7%, 36.8%, 32.8% and 34.6%, respectively, from the de-juiced leaves. For each cellulosic fraction, the glucose content was 71.6%, 69.6%, 67.8%, 66.7%, 69.7%, 68.6%, 63.9% and 61.7%, respectively. The structure of the cellulose samples was examined using FTIR and CP/MAS (13)C NMR spectroscopy and X-ray diffraction. The cellulosic preparations were free of bound lignin except for noticeable amounts of residual hemicelluloses (28.4-38.3%), and had intrinsic viscosities between 275.1 and 361.0 mL/g, along with molecular weights from 144,130 to 194,930 g/mol. This study found that the cellulose samples isolated from both de-juiced ryegrass leaves and the untreated leaves had a much lower percent crystallinity (33.0-38.6%) than that from wood-based fibres (60-70%) and had much shorter fibres (0.35-0.49 mm) than those of either cereal straws, bagasse or wood. In addition, a partial disruption of the hydrogen bonds and microfibrils may occur during the de-juicing process by mechanical activity, which results in a decreased cellulose crystallinity and fibre length. These findings are significant in relation to hydrolysing ryegrass cellulose for bio-ethanol production.

Rheumatoid arthritis: treatment which controls the C-reactive protein and erythrocyte sedimentation rate reduces radiological progression

One hundred and fifty consecutive patients with active, rheumatoid arthritis were assessed and treated with gold, D-penicillamine, chloroquine or dapsone. Four groups were selected from these patients. Group I consisted of 60 patients who did not complete 12 months' therapy. Group II consisted of patients in whom ESR and C-reactive protein (CRP) fell to less than 30 mm/h and less than 20 mg/l, respectively, and remained at these levels between 6 and 12 months. In group IV the ESR and CRP fell but remained greater than 30 and greater than 20, respectively, during the same period. Group III patients had variable ESRs and CRPs between 6 and 12 months. In groups II, III and IV there was a significant deterioration (p less than 0.01) in the hand and foot radiographs from 0 to 6 months. Between 6 and 12 months the radiographs in groups III and IV continued to show significant radiological progression (p less than 0.01), but those of group II did not alter. These results suggest radiological deterioration continues during the first 6 months regardless of clinical response but thereafter, further deterioration is less likely to occur when the ESR and CRP are consistently controlled.

Adrenergic control of circulating lymphocyte subpopulations. Effects of congestive heart failure, dynamic exercise, and terbutaline treatment

The current studies were undertaken to explore the relationship between enhanced sympathetic nervous activity and lymphocyte subset distribution in three settings: congestive heart failure, dynamic exercise, and beta-adrenergic agonist treatment. We compared the number and subset distribution of circulating lymphocytes in 36 patients with congestive heart failure and 31 age-matched control subjects. The number of circulating lymphocytes was lower in heart failure than in control. This was due to a reduction in Tsuppressor/cytotoxic and natural killer cells without significant alteration of Thelper cells. The extent of the alteration was similar in patients with idiopathic and ischemic heart failure, but the reduction was more pronounced in patients with New York Heart Association class III-IV than in class I-II. The plasma catecholamine elevation in heart failure was also independent of etiology but more pronounced in the more severely ill patients. We also assessed lymphocyte subsets after acute stimulation of sympathetic activity by dynamic exercise and after treatment with the beta-adrenergic agonist terbutaline. Dynamic exercise until exhaustion increased the number of circulating lymphocytes in healthy controls and heart failure patients in a subset-selective manner. By contrast, a 7-d treatment with terbutaline caused a reduction in the circulating number of lymphocytes in some subsets that was identical to that seen in heart failure patients. We conclude that prolonged sympathetic activity reduces the number of circulating lymphocytes by a beta-adrenergic mechanism. Such alterations might be involved in the pathophysiology of heart failure and other disease states involving increased activity of the sympathetic nervous system.

A new method for isolation of human lymphocyte subsets reveals differential regulation of beta-adrenergic receptors by terbutaline treatment

We adapted a technique for isolation of mononuclear leukocyte (MNL) subsets with immunomagnetic beads to the study of beta-adrenergic receptors. Mixed MNL cells were sequentially incubated with monoclonal antibodies specific for certain MNL subsets. Sheep antimouse antibodies coupled to magnetic beads were then added, and the desired MNL subset was pulled out with a magnet. This method yielded subsets with high purity and did not alter beta-receptor density or function. Healthy volunteers were treated for 7 days with the beta 2-selective agonist terbutaline (5 mg t.i.d.). Terbutaline treatment decreased beta-receptor number and isoproterenol-stimulated cyclic adenosine monophosphate (cAMP) generation in natural killer cells, helper T cells, and suppressor/cytotoxic T cells but not in B cells. The decrease was greatest in suppressor/cytotoxic T cells and least in helper T cells. Thus beta-adrenergic receptor regulation by agonists appears to differ among MNL subsets.

Plasma and synovial fluid concentrations of diclofenac sodium and its major hydroxylated metabolites during long-term treatment of rheumatoid arthritis

Plasma and synovial fluid concentrations of diclofenac sodium and its principal hydroxylated metabolites have been measured in sixteen rheumatoid patients on chronic therapy to investigate possible reasons for the drug's extended duration of action despite its apparent short elimination half-life in plasma. Diclofenac was detected in synovial fluid 2 h after dosing but at a lower level than in plasma. Thereafter synovial fluid concentrations remained relatively constant through to 11 h post-dosing whereas plasma levels in the same period declined rapidly from an initially high peak to near the sensitivity limit of the assay. Hydroxylated metabolites (free + conjugated) were rapidly formed with measurable concentrations of the 4' and 5 mono and dihydroxy derivatives being detected in plasma 2 h after dosing; levels of the 3' hydroxy metabolite were negligible at this time. Initially plasma levels of all metabolites were higher than those in synovial fluid but after 4 h synovial fluid levels were equal to or slightly higher than those in plasma. The significance of these findings is discussed in relation to the drug's overall clinical effect.

Development of a symptom based outcome measure for asthma

Measuring symptom specific health outcome is complex, but the methodologies now exist to develop measures with the appropriate properties. As one element of a major programme to develop multidomain health outcome measures for chronic disease, a symptom based measure for asthma care has been developed for use in general practice and outpatient departments. This article outlines the development process, which used a framework recently described in the theoretical literature to show the constraints that scientific criteria place on the development of outcome measures and the means of overcoming such limiting factors. Although substantial effort is required to undertake a rigorous process of development, useful tools are the result. Two five item, symptom based outcome measures for adult asthma are described.

The efficacy of femoral nerve block in pain reduction for outpatient hamstring anterior cruciate ligament reconstruction: a double-blind, prospective, randomized trial

The purpose of this study was to assess the efficacy of intraoperative femoral nerve block (FNB) in the reduction of postoperative pain following anterior cruciate ligament (ACL) hamstring reconstruction. Patients undergoing primary ACL reconstruction with hamstring tendon graft under general anesthetic who had signed an informed consent were included in the study. Patients were stratified to 4 surgeons and randomized to FNB with 0.25% bupivacaine or placebo of normal saline injected into the femoral nerve sheath before reversal of the general anesthetic. All patients received an intra-articular injection of bupivacaine at the beginning of their operative procedure. A single technique that included the use of a peripheral nerve stimulator was used for all FNBs. All patients were discharged on the day of surgery and given prescriptions for Tylenol 3. The Short-Form McGill Pain Questionnaire (SF-MPQ), a visual analog scale (VAS) for pain, and a medication diary recording Tylenol 3 usage were completed by patients in the recovery room, on the night of surgery, and on postoperative days 1, 2, and 3. There were complete data for 61 patients (FNB, 29; placebo, 32). An analysis of variance (ANOVA) test of the data showed no significant difference between the FNB and placebo group for pain reduction over the combined study period for both the SF-MPQ and VAS. However, the ANOVA does suggest that, on the night of surgery, there was a significant reduction in pain as measured with the VAS in the FNB group. A Student t test performed on the night of surgery data (SF-MPQ, P = .131; VAS, P = .0114; Tylenol 3, P = .076) showed a statistically significant difference between the FNB (39.4+/-21.0 mm) and placebo (56.8+/-24.6 mm) measured by VAS. Because this represented a difference of only 1.74 cm on a 10-cm VAS, it is unlikely to be clinically relevant. No difference was found in the amount of analgesic required on any day postoperatively. In conclusion, FNB may reduce pain on the night of surgery. However, this may not be clinically significant. FNB is not recommended at this time for use in outpatient ACL reconstruction with hamstring graft.

Combination therapy with gold and hydroxychloroquine in rheumatoid arthritis: a prospective, randomized, placebo-controlled study

We studied combination therapy with two slow-acting antirheumatic drugs given concurrently in active rheumatoid arthritis (RA). A 12-month prospective randomized controlled trial compared gold and hydroxychloroquine in 52 patients to gold and placebo in 49. The patients continued to receive non-steroidal anti-inflammatory drugs and analgesics. They were selected from three rheumatology centres in the West Midlands. Combination therapy led to a greater number of withdrawals due to adverse reactions (18 cases compared to 10 receiving gold/placebo). Patients completing 12 months' therapy (27 taking gold/hydroxychloroquine and 32 on gold/placebo) were compared using five clinical, seven laboratory, and one radiological measure. All 13 variables favoured gold/hydroxychloroquine with an overall advantage of 20-25% for the combination. This only reached statistical significance (at the 1% level) for C-reactive protein. An overall disease activity index was better at 12 months (at the 5% level) and showed a more rapid response with gold/hydroxychloroquine. This is the first randomized prospective placebo-controlled trial to show a significant advantage from a combination of two slow-acting drugs. There are many different ways of giving such combinations and we consider these should be explored to maximize the effectiveness of treatment for RA.

Hepatitis B virus (HBV)-specific cytotoxic T-cell response in humans: production of target cells by stable expression of HBV-encoded proteins in immortalized human B-cell lines

To analyze the hepatitis B virus (HBV)-specific cytotoxic T-cell (CTL) response during acute and chronic viral hepatitis, target cells that express HBV-encoded antigens in the context of the appropriate HLA restriction element must be available for each subject studied. Since HBV is not infectious for human cells in vitro, such target cells must be produced by DNA-mediated gene transfer into cultured human primary cells or cell lines. For this purpose, we have developed a panel of Epstein-Barr virus-based episomal expression vectors containing each of the HBV open reading frames under the transcriptional control of the simian virus 40 early promoter. Transfection of Epstein-Barr virus-immortalized B-cell lines with this panel of recombinants consistently leads to stable expression of the HBV envelope, nucleocapsid, and polymerase proteins. The HBV X gene product is transiently expressed following transfection, but stable expression of this protein cannot be maintained on a long-term basis. To assess the suitability of this system for the identification of HBV-specific CTL in humans, a panel of EBO-HBV transfectants of defined HLA haplotype was used to monitor the HBV-specific CTL response in a patient with acute viral hepatitis type B. Transfectants that stably express the HBV nucleocapsid (core) antigen were found to serve as excellent targets for the detection of HLA class I-restricted CTL that recognize endogenously synthesized HBV core antigen in this patient; they were also successfully used to stimulate the specific expansion of these CTL in vitro.

Effects of simulated domestic and international air travel on sleep, performance, and recovery for team sports

The present study examined effects of simulated air travel on physical performance. In a randomized crossover design, 10 physically active males completed a simulated 5-h domestic flight (DOM), 24-h simulated international travel (INT), and a control trial (CON). The mild hypoxia, seating arrangements, and activity levels typically encountered during air travel were simulated in a normobaric, hypoxic altitude room. Physical performance was assessed in the afternoon of the day before (D - 1 PM) and in the morning (D + 1 AM) and afternoon (D + 1 PM) of the day following each trial. Mood states and physiological and perceptual responses to exercise were also examined at these time points, while sleep quantity and quality were monitored throughout each condition. Sleep quantity and quality were significantly reduced during INT compared with CON and DOM (P < 0.01). Yo-Yo Intermittent Recovery level 1 test performance was significantly reduced at D + 1 PM following INT compared with CON and DOM (P < 0.01), where performance remained unchanged (P > 0.05). Compared with baseline, physiological and perceptual responses to exercise, and mood states were exacerbated following the INT trial (P < 0.05). Attenuated intermittent-sprint performance following simulated international air travel may be due to sleep disruption during travel and the subsequent exacerbated physiological and perceptual markers of fatigue.

Protein transfer of preformed MHC-peptide complexes sensitizes target cells to T cell cytolysis

Recombinant GPI-anchored HLA-A2.1 (HLA-A2.1-GPI/beta 2m) was used as a protein transfer vehicle to deliver a hepatitis B virus antigenic peptide to the surfaces of cytotoxic T cell targets. Empty HLA-A2.1-GPI/beta 2m was first produced in D. melanogaster cotransfectants and immunoaffinity purified. Cell coating with HLA-A2.1-GPI/beta 2m was shown to occur rapidly, and to be protein concentration dependent. Protein-transferred HLA-A2.1-GPI/beta 2m effectively presented a hepatitis B virus peptide to peptide-specific HLA-A2.1-restricted T cell clones in cytotoxicity assays. Protein transfer of functional GPI-modified class I MHC-antigenic peptide complexes represents a novel strategy for delivering functional antigenic complexes to cell surfaces that bypasses limitations of gene transfer and permits control of antigenic peptide densities at cell surfaces.