Left Ventricular Adaptation to 12 Weeks of Indoor Cycling at the Gym in Untrained Females

Cross-sectional studies provide evidence of larger cardiac dimensions and mass in endurance trained than in untrained females. Much less is known regarding adaptations in cardiac function following training in untrained subjects. We aimed to study left ventricular (LV) adaptation to indoor cycling in previously untrained females, in regard of LV dimensions, mass and function. 42 sedentary females were divided into 2 equally sized groups, either training indoor cycling at regular classes at a local gym for 12 weeks, in average 2.6 times per week, or maintaining their sedentary lifestyle. Echocardiography at rest and a maximal exercise test were performed before and after the intervention. Exercise capacity increased in average 16% in the exercise group (p<0.001), together with decreased heart rate at rest (p<0.05) and at 120 watts steady-state (p<0.001). There were no difference in systolic or diastolic function following the intervention and minimal increases in LV internal diameter in diastole (+1 mm, p<0.01). LV mass was unchanged with training (137±25 vs. 137±28 g, p=0.911). Our findings indicate that attending indoor cycling classes at a gym 2-to-3 times per week for 12 weeks is enough to improve exercise capacity, while a higher volume of training is required to elicit cardiac adaptations.

Echocardiographic Characterization of the Inferior Vena Cava in Trained and Untrained Females

The aim of the study was to explore the long- and short-axis dimensions, shape and collapsibility of the inferior vena cava in 46 trained and 48 untrained females (mean age: 21 ± 2 y). Echocardiography in the subcostal view revealed a larger expiratory long-axis diameter (mean: 24 ± 3 vs. 20 ± 3 mm, p < 0.001) and short-axis area (mean: 5.5 ± 1.5 vs. 4.7 ± 1.4 cm², p = 0.014) in trained females. IVC shape (the ratio of short-axis major to minor diameters) and the relative decrease in IVC dimension with inspiration were similar for the two groups. The IVC long-axis diameter reflected short-axis minor diameter and was correlated to maximal oxygen uptake (r = 0.52, p < 0.01). In summary, the results indicate that trained females have a larger IVC similar in shape and respiratory decrease in dimensions to that of untrained females. The long-axis diameter corresponded closely to short-axis minor diameter and, thus, underestimates maximal IVC diameter.

Detection and monitoring of human bocavirus 1 infection by a new rapid antigen test

Clinically relevant diagnosis of human bocavirus 1 (HBoV1) is challenging, as the virus is frequently detected in asymptomatic patients, and cofindings with other respiratory viruses are common. The clinical value of current diagnostic methods, such as PCR, is therefore low, and alternative diagnostic strategies are needed. We describe for the first time the use of an antigen detection assay for the rapid identification of HBoV1 in a paediatric patient with respiratory tract infection symptoms. We estimate the duration of active HBoV1 infection to be 6 days.

Cardiac systolic regional function and synchrony in endurance trained and untrained females

Background

Most studies on cardiac function in athletes describe overall heart function in predominately male participants. We aimed to compare segmental, regional and overall myocardial function and synchrony in female endurance athletes (ATH) and in age-matched sedentary females (CON).

Methods

In 46 ATH and 48 CON, echocardiography was used to measure peak longitudinal systolic strain and myocardial velocities in 12 left ventricular (LV) and 2 right ventricular (RV) segments. Regional and overall systolic function were calculated together with four indices of dyssynchrony.

Results

There were no differences in regional or overall LV systolic function between groups, or in any of the four dyssynchrony indices. Peak systolic velocity (s′) was higher in the RV of ATH than in CON (9.7±1.5 vs 8.7±1.5 cm/s, p=0.004), but not after indexing by cardiac length (p=0.331). Strain was similar in ATH and CON in 8 of 12 LV myocardial segments. In septum and anteroseptum, basal and mid-ventricular s′ was 6–7% and 17–19% higher in ATH than in CON (p<0.05), respectively, while s′ was 12% higher in CON in the basal LV lateral wall (p=0.013). After indexing by cardiac length, s′ was only higher in ATH in the mid-ventricular septum (p=0.041).

Conclusions

We found differences between trained and untrained females in segmental systolic myocardial function, but not in global measures of systolic function, including cardiac synchrony. These findings give new insights into cardiac adaptation to endurance training and could also be of use for sports cardiologists evaluating female athletes.

Decreased aerobic capacity 4 years after aortic valve replacement in male patients operated upon for chronic aortic regurgitation

Exercise testing is underutilized in patients with valve disease. We have previously found a low physical work capacity in patients with aortic regurgitation 6 months after aortic valve replacement (AVR). The aim of this study was to evaluate aerobic capacity in patients 4 years after AVR, to study how their peak oxygen uptake (peakVO₂) had changed postoperatively over a longer period of time. Twenty-one patients (all men, 52 ± 13 years) who had previously undergone cardiopulmonary exercise testing (CPET) pre- and 6 months postoperatively underwent maximal exercise testing 49 ± 15 months postoperatively using an electrically braked bicycle ergometer. Breathing gases were analysed and the patients' physical fitness levels categorized according to Åstrand's and Wasserman's classifications. Mean peakVO₂ was 22·8 ± 5·1 ml × kg⁻¹ × min⁻¹ at the 49-month follow-up, which was lower than at the 6-month follow-up (25·6 ± 5·8 ml × kg⁻¹ × min⁻¹, P = 0·001). All but one patient presented with a physical fitness level below average using Åstrand's classification, while 13 patients had a low physical capacity according to Wasserman's classification. A significant decrease in peakVO₂ was observed from six to 49 months postoperatively, and the decrease was larger than expected from the increased age of the patients. CPET could be helpful in timing aortic valve surgery and for the evaluation of need of physical activity as part of a rehabilitation programme.

Comparison of Th-cell immunity against human bocavirus and parvovirus B19: proliferation and cytokine responses are similar in magnitude but more closely interrelated with human bocavirus

Human parvovirus B19 (B19) has been, for decades, the only parvovirus known to be pathogenic in humans. Another pathogenic human parvovirus, human bocavirus (HBoV), was recently identified in respiratory samples from children with acute lower respiratory tract symptoms. Both B19 and HBoV are transmitted by the respiratory route. The vast majority of adults are IgG seropositive for HBoV, whereas the HBoV-specific Th-cell immunity has not much been studied. The aim of this study was to increase our knowledge on HBoV-specific Th-cell immunity by examining HBoV-specific T-cell proliferation, Interferon-gamma (IFN-γ), IL-10 and IL-13 responses in 36 asymptomatic adults. Recombinant HBoV VP2 virus-like particles (VLP) were used as antigen. HBoV-specific responses were compared with those elicited by B19 VP2 VLP. Proliferation, IFN-γ and IL-10 responses with HBoV and B19 antigens among B19-seropositive subjects were statistically similar in magnitude, but the cytokine and proliferation responses were much more closely correlated in HBoV than in B19. Therefore, at the collective level, B19-specific Th-cell immunity appears to be more divergent than the HBoV-specific one.

Clinical characteristics, outcome and the role of viral load in nontransplant patients with Epstein-Barr viraemia

Epstein-Barr virus (EBV) is important in the development of post-transplant lymphoproliferative disease in allogeneic stem cell and solid organ transplant recipients. We have studied the clinical significance of EBV DNAaemia among nontransplant patients in a tertiary referral hospital. We retrospectively reviewed the medical records for main diagnosis, outcome, immunosuppressive/cytotoxic chemotherapy and other opportunistic infections of the patients who were found positive in quantitative real-time PCR assay for EBV (EBV-qPCR) between the years 2000 and 2007. Allogeneic stem cell and solid organ transplant recipients were excluded, and all patients in nonsurgical adult wards were included. Altogether, 62 patients had at least one plasma sample positive with an EBV-qPCR. Fifteen were immunocompetent, most had primary EBV infection, and the outcome was good. On the other hand, 36 had malignant disease, seven had HIV infection and seven had immunosuppressive conditions of an other aetiology. All but one of the malignancies were of lymphoid origin, and most of these patients had a history of multiple cytotoxic treatments. Immunosuppressed patients had higher viral loads. EBV viraemia is associated with severe immunosuppression and lymphoid malignancies.

ErbB-3 expression is associated with E-cadherin and their coexpression restores response to gefitinib in non-small-cell lung cancer (NSCLC)

BACKGROUND

Epidermal growth factor receptor (EGFR) inhibitors are effective in a subset of patients with non-small-cell lung cancer (NSCLC). We previously showed that E-cadherin expression associates with gefitinib activity. Here, we correlated the expressions of ErbB-3 and E-cadherin in NSCLC tumors and cell lines, their effect on response to gefitinib, and induction of both by the histone deacetylase (HDAC) inhibitors vorinostat and SNDX-275.

METHODS

Real-time RT-PCR was carried out on RNA isolated from 91 fresh-frozen NSCLC samples and from 21 NSCLC lines. Protein expression was evaluated with western blot and flow cytometry. Apoptosis was assessed using vibrant apoptosis assay.

RESULTS

Expressions of E-cadherin and ErbB-3 correlated significantly in primary tumors (r = 0.38, P < 0.001) and in cell lines (r = 0.88, P < 0.001). Cotransfection of ErbB-3 and E-cadherin in a gefitinib-resistant cell line showed enhanced apoptotic response to gefitinib. vorinostat and SNDX-275 induced ErbB-3 and E-cadherin in gefitinib-resistant cell lines. When gefitinib-resistant lines were treated with vorinostat and gefitinib, synergistic effects were detected in four of the five lines tested.

CONCLUSION

ErbB-3 and E-cadherin are coexpressed and induced by HDAC inhibitors. For tumors with low ErbB-3 and E-cadherin expressions, the combination of HDAC and EGFR-tyrosine kinase inhibitors increased expression of both genes and produced more than additive apoptotic effect.

Frequency of recent parvovirus infection in patients examined for acute reactive arthritis. A study with combinatorial parvovirus serodiagnostics

OBJECTIVE

To determine the causative role of human parvovirus B19 as a preceding infection in patients examined for acute reactive arthritis (ReA).

METHODS

Sixty adult patients with acute arthritis were screened for evidence of triggering infections. In all patients, cultures of stool specimens and of Chlamydia trachomatis in urethra/cervix, and/or bacterial serology were studied. The timing of primary infection of human parvovirus B19 was determined by measurement in serum of VP2-IgM, VP2-IgG, epitope-type specifity of VP2-IgG, and avidity of VP1-IgG.

RESULTS

Median time from onset of joint symptoms to the rheumatological consultation was five weeks (range 1-62). Of the 60 patients, 35 fulfilled the diagnostic criteria for ReA; in the remaining, the diagnosis was unspecified arthritis (UA). Thirty-six patients had antibodies for the B19 virus. Occurrence of these antibodies did not differ significantly between ReA and UA groups (P = 0.61). Of these 36 patients, 34 had a pre-existing immunity to the B19 virus. Of the two other patients, one had rash and self-limiting polyarthritis with serological evidence of B19 primary infection, and the other had arthritis of the lower extremities with serological evidence of a convalescence period after the B19 primary infection. The latter patient also had antibodies to Yersinia, with a clinical picture typical for ReA.

CONCLUSION

In patients examined for acute ReA, the frequency of recent B19 virus infection was 3.3% (2 out of 60). The diagnostic utility of the presented methodology, by using a single serum sample, was evident.

T helper cell-mediated interferon-gamma expression after human parvovirus B19 infection: persisting VP2-specific and transient VP1u-specific activity

Human parvovirus B19 is a small non-enveloped DNA virus with an icosahedral capsid consisting of proteins of only two species, the major protein VP2 and the minor protein VP1. VP2 is contained within VP1, which has an additional unique portion (VP1u) of 227 amino acids. We determined the ability of eukaryotically expressed parvovirus B19 virus-like particles consisting of VP1 and VP2 in the ratio recommended for vaccine use, or of VP2 alone, to stimulate, in an HLA class II restricted manner, peripheral blood mononuclear cells (PBMC) to proliferate and to secrete interferon gamma (IFN-gamma) and interleukin (IL)-10 cytokines among recently and remotely B19 infected subjects. PBMC reactivity with VP1u was determined specifically with a prokaryotically expressed VP1u antigen. In general, B19-specific IFN-gamma responses were stronger than IL-10 responses in both recent and remote infection; however, IL-10 responses were readily detectable among both groups, with the exception of patients with relapsed or persisting symptoms who showed strikingly low IL-10 responses. Whereas VP1u-specific IFN-gamma responses were very strong among the recently infected subjects, the VP1u-specific IFN-gamma and IL-10 responses were virtually absent among the remotely infected subjects. The disappearance of VP1u-specific IFN-gamma expression is surprising, as B-cell immunity against VP1u is well maintained.

IgG subclass response to human parvovirus B19 infection

BACKGROUND

IgG antibodies are essential to immunity against human parvovirus B19 and can neutralize infection both in bone marrow cell cultures infected in vitro and in chronically infected immunosuppressed individuals.

OBJECTIVES

To assess the levels and response kinetics of IgG subclasses towards individual structural proteins of human parvovirus B19.

STUDY DESIGN

Subclasses of IgG for capsid proteins VP1 or VP2 were quantified by EIA using monoclonal antibodies in 30 acutely infected and 30 convalescent patients, as well as in 32 remotely infected and 20 non-infected controls.

RESULTS

In all groups of seropositive individuals the predominant subclass for either structural protein was IgG1. Subclass IgG3 was associated with acute infection. By contrast, IgG4 appeared months after infection, and occurred specifically towards VP1. The ratio of VP1-specific subclasses IgG3 and IgG4 provided a diagnostic test for recent infection with a specificity of 98% and a sensitivity of 97%.

CONCLUSIONS

Comparative measurement of VP1-specific IgG3 and IgG4 is useful in diagnosis. The IgG4 results point to long-term expression of immunologically active VP1 and to T-cell help of T(h)2 type for B-cells recognizing VP1.

Delayed maturation of IgG avidity in congenital toxoplasmosis

The aim of this comparative study was to investigate the clinical usefulness of the measurement of Toxoplasma gondii IgG avidity in the postnatal diagnosis of congenital toxoplasmosis. IgG avidity values in serum samples from infants with congenital infection were compared with those in samples from uninfected infants, all born to mothers with toxoplasmosis acquired during gestation. This analysis revealed that IgG avidity values soon after birth reflected maternal values in the large majority of the samples. Low or borderline IgG avidity values were systematically found in the cohort of congenitally infected subjects. After birth, IgG avidity values slowly increased over time for up to 2 years in congenitally infected subjects. On the contrary, IgG avidity values in the uninfected infants remained stable over time. The presence of low IgG avidity in a newborn can be considered a marker of maternal seroconversion in the second or third trimester of gestation and, as a consequence, an indicator of risk for congenital toxoplasmosis. An IgG avidity assay can be easily carried out with antibodies eluted from dried blood spots (Guthrie cards), providing an opportunity to retrospectively evaluate the risk of congenital infection in special clinical circumstances, for example when suspicion of congenital infection arises during late infancy.

Genoprevalence in human tissues of TT-virus genotype 6

TT virus (TTV) is a newly discovered human virus of high genotypic diversity. TTV is widely distributed among humans, but the possible genotype-related differences in TTV biology are not well known. The prevalence and amount of TTV-DNA, especially of genotype 6, was determined by nested-PCR in various human tissues, and human parvovirus B19, another ssDNA virus, was used as a reference. TTV DNA was detected simultaneously in bile, peripheral blood mononuclear cells (PBMC) and plasma of 77% subjects, in 38% skin samples, in 38% synovial samples and in all (100%) adenoids, tonsils and liver samples. The relative concentrations of TTV-DNA did not vary significantly among the different samples. Genotype 6 TTV-DNA was detected in bile and plasma of one subject (3%), in skin and serum of one subject (8%) and in one liver (5%). The overall prevalence of TTV genotype 6 was 4% in subjects and 4% in sera. TTV genotype 6 was shown to occur in human tissues with no obvious tissue-type or symptom specificity. Parvovirus B19 DNA was detected overall in 38% subjects, and bile was the only sample type tested that did not persistently harbour B19 DNA.

High incidence of PTLD after non-T-cell-depleted allogeneic haematopoietic stem cell transplantation as a consequence of intensive immunosuppressive treatment

The occurrence of post-transplant lymphoproliferative disorder (PTLD) in relation to immunosuppressive treatment was determined in 257 patients treated with non-T-cell-depleted allogeneic stem cell transplantation from an HLA-matched sibling (173 patients) or unrelated donor (84 patients). The conditioning consisted of total body irradiation and cyclophosphamide (myeloablative conditioning, 250 patients), or fludarabine combined with cyclophosphamide or a single 2 Gy dose of TBI (nonmyeloablative conditioning, seven patients). In transplantations from an unrelated donor, the patients also received antithymocyte globulin (ATG). The prophylaxis against graft-versus-host disease (GVHD) consisted of cyclosporine A, methotrexate, and methylprednisolone. The autopsy reports of deceased patients were systematically reviewed, and the autopsy materials of cases suggestive of PTLD were re-examined histologically for Epstein-Barr virus (EBV). Nineteen patients with EBV-positive PTLD were identified, of whom six had been transplanted from a sibling donor and 13 from an unrelated donor. All the patients who developed PTLD had been given ATG either for the treatment of steroid-resistant acute GVHD (all PTLD patients with a sibling donor and one with an unrelated donor), or as part of the conditioning (all patients with an unrelated donor). In conclusion, in transplantations from an HLA-identical donor with a non-T-cell-depleted graft, the risk of PTLD correlated strongly with the intensity of the immunosuppressive treatment.

Malignancies after heart transplantation: presence of Epstein-Barr virus and cytomegalovirus

The presence of Epstein-Barr virus (EBV), human papilloma virus (HPV), and cytomegalovirus (CMV) was studied in 20 patients who developed malignancies after heart transplantation in the Helsinki University Central Hospital. The tumors were analyzed for the presence of HPV by polymerase chain reaction and for EBV by in situ hybridization. Clinical CMV infection was verified by immunochemical quantitation of CMV antigen in peripheral blood cells. HPV was detected in one of the eight epithelial malignant tumors studied. Three of the six lymphomas were positive for EBV. Two (67%) of 3 patients with EBV-positive lymphomas and one (33%) of the other three lymphomas but only 2 (14%) of 14 patients who developed other malignancies had a history of a manifest post-transplantation CMV infection prior to the development of malignancy. These results confirm the presence of EBV in lymphomas of heart transplant recipients and suggest that CMV might have a contributory role in the development of EBV-associated lymphomas.

Multicenter evaluation of strategies for serodiagnosis of primary infection with Toxoplasma gondii

The diagnostic performance of single-serum assays for toxoplasma-specific immunoglobulin (Ig)M. IgA. IgG, and IgE antibodies and of different combinations of such antibody assays in 20 European reference centers was assessed. A panel of 276 sera, of which 73 came from patients who seroconverted within 3 months (acute infection), 49 from patients who had seroconverted 3-12 months earlier (convalescence), and 154 from subjects who had two IgG-positive samples obtained 12 months apart (past infection), was tested with 20 toxoplasma-antibody assays and 195 combinations. In general, every assay with high diagnostic sensitivity showed low diagnostic specificity, i.e. no assay performed alone could reliably distinguish acute from past infection. Furthermore, no single assay (or combination) could separate convalescence from the other stages of toxoplasma infection. However, excellent diagnostic performances were reached by sequential use of highly sensitive IgM assays and methods examining IgG avidity or stage specificity. IgA or IgM assays were less suitable for confirmation of toxoplasma-IgM positivity. This study documents the strength of test combinations in assessing the stage of toxoplasma infection.

Diagnosis of human parvovirus B19 infections by detection of epitope-type-specific VP2 IgG

In the B19 VP2 molecule an immunodominant heptapeptide epitope has been detected, recently for which IgG antibodies are synthesized exclusively in the acute phase of B19 infection. Using this acute-phase-specific epitope (KYVTGIN) a 2(nd)-generation epitope-type EIA was developed, which compares serum IgG activity for native VP2 capsids exhibiting conformational VP2 epitopes with IgG activity for the KYVTGIN epitope. In this study the diagnostic performance (clinical sensitivity and specificity) of the 1st and 2nd-generation epitope-type EIAs and of a peptide-based EIA utilising as antigen the KYVTGIN epitope alone was assessed in comparison with various high-quality IgM- and IgG- based B19 assays. Serum samples from 489 patients with B19-related symptoms and asymptomatic controls from three countries were studied. Among 323 patients with B19-IgG, 20% were diagnosed as acute infection, 73% had past immunity and 7% were not classified due to contradictory results among the different assays. The unclassified samples were explored for viral strain diversity by PCR and DNA sequencing but all sequences obtained were B19-like with variance of only a few per cent. The 2nd-generation epitope-type EIA had a diagnostic sensitivity of 98% and a diagnostic specificity of 94%. In combination with conventional approaches, the epitope-type assays increase greatly the accuracy of B19 serodiagnosis.

T helper cell-mediated in vitro responses of recently and remotely infected subjects to a candidate recombinant vaccine for human parvovirus b19

T cell proliferation to human parvovirus B19 antigen was measured in 6 patients with recent B19 infection (1 with pneumonia and pleuritis), 1 patient with symptoms persisting >180 days after onset, 18 nonsymptomatic subjects with remote B19 immunity, and 12 B19-seronegative control subjects. Recombinantly expressed virus-like particles (VP1/2 capsids), a candidate B19 vaccine, were used as antigen. Virus-specific T helper cell proliferation was detectable in all the recently infected patients and in most (17/18) of the remotely infected subjects but not in the seronegative control subjects. The B19-specific T cell responses, in general, were most vigorous among the recently infected patients. However, such strong B19-specific proliferation was not confined within the acute phase, as 28% (5/18) of the remotely infected healthy individuals had B19-specific reactivity persisting at acute-phase levels, apparently for years or decades. These data indicate that B cells recognizing the VP1/2 capsids receive class II-restricted help from CD4(+) T lymphocytes.

Seroetiology of acute lower respiratory infections among hospitalized children in Beijing

BACKGROUND

Little is known of the etiology of childhood acute lower respiratory infections in China, where the use of antimicrobials is indiscriminate. Trials to change such a policy require etiologic data, especially on the bacteria most relevant to these common diseases.

METHODS

One hundred consecutive infants and children from 3 months to 14 years of age with symptoms and signs compatible with acute lower respiratory infections were studied prospectively in the largest pediatric hospital in Beijing from February to May, 1997. Blood culture, thorax radiography and paired sera for 20 microbiologic assays were taken, and the course of illness was monitored uniformly. Disease severity was graded.

RESULTS

In 24 cases there was evidence only of bacterial etiology, and in 5 solely viral agents were found; 3 children probably had a mixed bacterial-viral infection. Surprisingly no pneumococcal infection was detected, Mycoplasma pneumoniae (n = 21), Haemophilus influenzae type b (n = 8) and Chlamydia pneumoniae (n = 7) being the dominant bacteria. All children recovered.

CONCLUSIONS

Routine use of antimicrobials for these patients seems unjustified. Serologic evidence for the H. influenzae type b etiology is encouraging in terms of vaccination, but confirmatory studies are needed.

Direct ex vivo measurement of CD8(+) T-lymphocyte responses to human parvovirus B19

Parvovirus B19 is a common human pathogen which can cause severe syndromes, including aplastic anemia and fetal hydrops. The mapping of the first parvovirus B19-derived CD8(+) T-lymphocyte epitope is described. This HLA-B35-restricted peptide derives from the nonstructural (NS1) protein and is strongly immunogenic in B19 virus-seropositive donors.

Identification of a novel RNA splicing pattern as a basis of restricted cell tropism of erythrovirus B19

Prior studies on the transcription of erythrovirus B19 have identified a short leader sequence associated with all spliced viral transcripts. While some variability has been observed in the acceptor for this first intron, studies to date in both permissive and nonpermissive cell types have reported a unique splice donor site. In the semipermissive MB-02 cell line, we have found that splicing of this first intron proceeds almost exclusively via a cryptic CT donor downstream of the previously reported GT donor at nucleotide 406. The resulting messages for the viral structural proteins and 11-kDa protein are thereby made bicistronic, with the first expressible polypeptide being a 34 amino acid fusion of the NS-1 and 7.5-kDa proteins. The presence of an upstream open-reading frame on these messages is likely to block effective translation of the downstream structural protein products. We propose this as a significant mechanism in determining B19's tropism on the basis of host cell splicing machinery, and present evidence in support of this model. Additionally, this is the first report of usage of a noncanonical splice donor in B19, and to our knowledge the first report of a CT-AG splice in any system.

FGF4 and INT2 oncogenes are amplified and expressed in Kaposi's sarcoma

Kaposi's sarcoma (KS) is a vascular tumor, the pathogenesis of which has been suggested to include human herpesvirus 8 (HHV-8) as well as various cytokines and growth factors. Very little is known about cytogenetic and molecular genetic changes in KS. We studied DNA copy number changes in KS and found a recurrent gain at 11q13. We then analyzed the amplification and expression status of two known oncogenes, FGF4 and INT2, residing at 11q13. Comparative genomic hybridization, interphase fluorescence in situ hybridization with yeast artificial chromosome probes containing FGF4 and INT2, and immunoperoxidase immunostaining with anti-FGF4 and -INT2 antibodies were used on 12 KS samples. All samples tested were shown by polymerase chain reaction to be HHV-8 positive. A recurrent gain at 11q13 was shown by comparative genomic hybridization in 4 of 10 cases studied. Of six cases studied by interphase fluorescence in situ hybridization, four showed a 3- to 4-fold amplification with the probes containing FGF4 and INT2. Expression of FGF4 and INT2 was found in nine and three cases, respectively, of nine studied. Amplification and expression of these genes is particularly interesting in the context of oncovirus involvement, because INT2 is a homolog of mouse int2 which causes mammary carcinoma in mice when activated by integration of retrovirus mouse mammary tumor virus. This raises the question of whether HHV-8 represents an integrating oncovirus that causes amplification and activation of genomic oncogenes in humans.

Integrity and full coding sequence of B19 virus DNA persisting in human synovial tissue

Primary infection by human parvovirus B19 is often accompanied by arthropathy of varying duration, of which the most severe cases can be indistinguishable from rheumatoid arthritis (RA). While this might seem to imply a role in RA pathogenesis, recent studies have verified long-term persistence of B19 DNA in synovial tissue not only in patients with rheumatoid or juvenile arthritis, but also in immunocompetent, non-arthritic individuals with a history of prior B19 infection. However, the latter data are based on PCR amplification of short segments of DNA, with little sequence information. We determined the nucleotide sequence and examined the integrity of the protein-coding regions of B19 genomes persisting in synovial tissue and compared the results with data from synovial tissues of recently infected patients. In synovium of both previously and recently infected subjects, the viral coding regions were found to be present in an apparently continuous, intact DNA molecule. Comparison with sequences reported from blood or bone marrow showed that the synoviotropism or persistence of the B19 virus DNA was not due to exceptional mutations or particular genotype variants. The synovial retention of full-length viral genomes may represent a physiological process functioning in long-term storage of foreign macromolecules in this tissue.

Secondary measles vaccine failures identified by measurement of IgG avidity: high occurrence among teenagers vaccinated at a young age

Failure to seroconvert (primary vaccine failure) is believed to be the principal reason (approx. > 95%) why some vaccinees remain susceptible to measles and is often attributed to the persistence of maternal antibodies in children vaccinated at a young age. Avidity testing is able to separate primary from secondary vaccine failures (waning and/or incomplete immunity), but has not been utilized in measles epidemiology. Low-avidity (LA) and high-avidity (HA) virus-specific IgG antibodies indicate primary and secondary failure, respectively. Measles vaccine failures (n = 142; mean age 10.1 years, range 2-22 years) from an outbreak in 1988-9 in Finland were tested for measles-virus IgG avidity using a protein denaturating EIA. Severity of measles was recorded in 89 failures and 169 non-vaccinees (mean age 16.2 years, range 2-22 years). The patients with HA antibodies (n = 28) tended to have clinically mild measles and rapid IgG response. Among failures vaccinated at < 12, 12-15 and > 15 months of age with single doses of Schwarz-strain vaccine in the 1970s, 50 (95% CI 1-99), 36 (CI 16-56) and 25% (CI 8-42) had HA antibodies, respectively. When a single measles, mumps and rubella (MMR) vaccine had been given after 1982 at 15 months of age, only 7% (CI 0-14) showed HA antibodies. Omitting re-vaccinees and those vaccinated at < 15 months, Schwarz-strain recipients had 3.6 (CI 1.1-11.5) higher occurrence of HA responses compared to MMR recipients. Apart from one municipality, where even re-vaccinees had high risk of primary infection, 89% (CI 69 to approximately 100) of the infected re-vaccinees had an HA response. Secondary measles-vaccine failures are more common than was more previously thought, particularly among individuals vaccinated in early life, long ago, and among re-vaccinees. Waning immunity even among individuals vaccinated after 15 months of age, without the boosting effect of natural infections should be considered a relevant possibility in future planning of vaccination against measles.

A pooled-data analysis of three randomized, double-masked, six-month clinical studies comparing the intraocular pressure reducing effect of latanoprost and timolol

PURPOSE

To compare the intraocular pressure (IOP) reduction by latanoprost and timolol, and to study factors of prognostic value for assessing this reduction.

METHODS

We analyzed 829 patients included in three phase 111 studies comparing six months' treatment with 0.005% latanoprost once daily and 0.5% timolol twice daily in patients with open-angle glaucoma or ocular hypertension. Analysis of covariance controlled for differences in baseline IOP and sex was used to assess the IOP reduction.

RESULTS

Latanoprost reduced diurnal IOP (average of morning, noon and afternoon assessments) by 7.7 mmHg (31%) and timolol by 6.5 mmHg (26%) after six months of treatment. Thus the diurnal IOP was reduced 1.2 mmHg (18%) more with latanoprost than with timolol (p<0.001). Latanoprost-treated patients showed a further decrease in morning IOP of 0.7 mmHg (9%, p<0.001) from the initial morning IOP reduction obtained at two weeks. No such further decrease in IOP was seen with timolol. Higher baseline diurnal IOP resulted in a larger diurnal reduction during treatment with both drugs (p<0.001). Diurnal IOP in women was reduced 0.7 mmHg (11%) less than males with both drugs (p<0.001).

CONCLUSIONS

Latanoprost was more effective than timolol in reducing mean diurnal IOP. The effect after two weeks was maintained for timolol while with latanoprost there was a further, significant IOP reduction from two weeks to six months. Baseline IOP was the only factor of clinical importance found to be of prognostic value for assessing the IOP reduction.

Acute-Phase-Specific Heptapeptide Epitope for Diagnosis of Parvovirus B19 Infection

The major capsid protein VP2 of human parvovirus B19, when studied in a denatured form exhibiting linear epitopes, is recognized exclusively by immunoglobulin G (IgG) antibodies of patients with acute or recent B19 infection. By contrast, conformational epitopes of VP2 are recognized both by IgG of the acute phase and by IgG of past immunity. In order to localize the VP2 linear epitope(s) specific for acute-phase IgG, the entire B19 capsid protein sequence was mapped by peptide scanning using well-characterized acute-phase and control sera. A unique heptapeptide epitope showing strong and selective reactivity with the acute-phase IgG was detected and characterized. By using this linear epitope (VP2 amino acids 344 to 350) and virus-like particles exhibiting conformational VP2 epitopes, an innovative approach, second-generation epitope-typing enzyme immunoassay, was set up for improved diagnosis of primary infections by human parvovirus B19.

Immunoblot analysis of natural and vaccine-induced IgG responses to rubella virus proteins expressed in insect cells

BACKGROUND

The three structural proteins of rubella virus (RV), the capsid protein C and the envelope glycoproteins E1 and E2, were produced individually in soluble form in Sf9 insect cells using the baculovirus system. All proteins were equipped with a polyhistidine tag at their C-terminal ends to enable gentle purification by metal ion affinity chromatography. In addition, the E1 and E2 proteins were engineered to display the FLAG epitope tag at their N-terminal ends.

STUDY DESIGN

The diagnostic potential of the recombinant purified proteins was evaluated by immunoblot and enzyme immuno assays (EIA) using a total of 57 well-characterised serum samples obtained at various time points after natural RV infection, congenital rubella syndrome (CRS), MMR vaccination or from controls with past RV immunity. In addition, acute and convalescent phase serum pools from a total of 20 patients were evaluated. Authentic RV proteins were used as a reference.

RESULTS

The recombinant E1 and C proteins were predominant in eliciting the immune response in both postnatal and vaccinal RV infections, being much weaker in the vaccinal ones. The IgG response to the recombinant C protein was very strong after the first month post infection and decreased with time. The immune response against the recombinant E2 protein, however, was generally poor, but notably stronger after congenital infection. Together, the results showed that the individual recombinant protein antigens could be suitable for diagnosis of RV infection and for study of the immune response to rubella vaccination.

A new method with general diagnostic utility for the calculation of immunoglobulin G avidity

The reference method for immunoglobulin G (IgG) avidity determination includes reagent-consuming serum titration. Aiming at better IgG avidity diagnostics, we applied a logistic model for the reproduction of antibody titration curves. This method was tested with well-characterized serum panels for cytomegalovirus, Epstein-Barr virus, rubella virus, parvovirus B19, and Toxoplasma gondii. This approach for IgG avidity calculation is generally applicable and attains the diagnostic performance of the reference method while being less laborious and twice as cost-effective.

Prevalence of parvovirus B19 DNA in bone marrow of patients with haematological disorders

Patients with haematological disorders (n = 100) were examined for prevalence of parvovirus B19 DNA in the bone marrow and serum, irrespective of B19-related symptoms. B19 DNA was studied using 2 nested PCRs and the serum samples were further analysed with B19-specific IgG, IgM and avidity as well as seroreactivity against linear and conformational epitopes of the B19 VP2 antigen. The latter assays specify whether the IgG antibody response represents acute or past B19 infection. B19 DNA was detected in 4 of the 100 bone marrow samples, whereas all the serum samples were B19 DNA negative. None of the 4 B19 DNA positive patients had symptoms typical of B19 infection and serology showed past infection. Furthermore, 2 were still B19 DNA positive in bone marrow more than 1 y after the first sample indicating virus persistence. The seroprevalence for B19 IgG was 59% and 2 patients were B19 IgM positive. Thus, presence of B19 DNA in bone marrow from patients with haematological disorders is not a general finding in seropositive patients. B19 DNA can persist in bone marrow, but in our material this finding showed no clear correlation with symptomatic B19 infection.

Treatment of toxoplasmosis during pregnancy: a multicenter study of impact on fetal transmission and children's sequelae at age 1 year

OBJECTIVE

Toxoplasmosis during pregnancy can cause fetal infection, with unpredictable sequelae in later life. We measured the effects of prenatal antibiotic therapy on the fetomaternal transmission of Toxoplasma gondii and on the appearance of sequelae in the congenitally infected child at age 1 year.

STUDY DESIGN

In a multicenter study we investigated consecutive women with Toxoplasma seroconversion during pregnancy. Data were obtained from 144 women recruited in 5 different Toxoplasma reference centers. Through multivariate analysis we assessed the association between transmission and appearance of sequelae as a function of the following parameters: estimated gestational age at infection, administration of antibiotic therapy, duration of antibiotic therapy, and time lapse between infection and the start of antibiotic therapy.

RESULTS

Sixty-four of the 144 women (44%) gave birth to a congenitally infected infant. Multivariate analysis showed that transmission was predicted neither by whether antibiotics had been administered nor by the time lapse between infection and the start of antibiotic therapy, but only by the gestational age at which maternal infection occurred (P <.0001). Sequelae were found in 19 children (13%), 9 of whom (6%) had severe sequelae. Administration of antibiotics was predictive of the absence of sequelae (P =.026, odds ratio 0.30, 95% confidence interval 0.104-0.863), in particular the absence of severe sequelae (P =.007, odds ratio 0.14, 95% confidence interval 0.036-0.584). The sooner antibiotics were given after the infection, the less frequently sequelae were seen (P =. 021).

CONCLUSION

Prenatal antibiotic therapy after toxoplasmosis during pregnancy had no impact on the fetomaternal transmission rate but reduced the rate of sequelae among the infected infants. The early start of treatment resulted in a significant reduction in the number of severely affected infants.

Immunoreactivation of Epstein-Barr virus due to cytomegalovirus primary infection

Serological diagnosis of herpes virus infections is hampered by concurrent expression of IgM for heterologous members of this virus family. To assess the frequency of such multiple diagnostic findings and to understand their etiology, we sought by using IgG, IgM, and IgG avidity test serodiagnoses for Epstein-Barr virus (EBV) among immunocompetent or immune-suppressed patients with well-documented cytomegalovirus (CMV) primary infection. Controls had primary infection by EBV or had acute septic or severe respiratory infection. Among EBV-seropositive patients with CMV primary infection, a large proportion (13/56, 23%) showed antibody profiles of EBV reactivation: seroconversion of VCA IgM and/or > or = fourfold rise of VCA IgG, together with high or intermediate avidity of VCA IgG. Most of the CMV patients with EBV serodiagnosis showed also diagnostic HHV-6 antibody rises. In contrast to the frequently occurring CMV-induced EBV immunoreactivation, EBV primary infections did not appear to induce immunoreactivations of CMV (0/22). Only one (2%) CMV patient had a significant varicella zoster virus (VZV) antibody rise. The studies show that CMV is a particularly active inducer of some, but not all, members of the herpes virus family and suggest that the in vivo interplay between CMV and EBV occurs unidirectionally. The high frequency of heterologous herpes virus immunoreactivations poses demands on laboratory diagnosis.