Rubella cataract in vitro: Sensitive period of the developing human lens.

The clinically known sensitive period of rubella cataract was studied in vitro by infecting 79 human eye rudiments from embryos aged 4-10 wk with rubella virus. The course of the infection was followed by histological and indirect immunofluorescence methods. Of the rudiments, 12 pairs were in the lens placode or open-lens-vesicle stage, 40 already had closed lens vesicles and in another 27 closed-stage pairs an incision was made in the lens capsule before infection to allow the virus to enter the lens. Uninfected controls differentiated well in vitro for 4-6 wk. The eye rudiments infected in the open-lens-vesicle stage showed lens fiber destruction and viral antigens within the lens. No damage or viral antigens were detected in rudiments infected in the closed stage unless the lens capsule was incisedmwhen this was done, however, fiber damage ensued and viral antigens appeared. The lens capsule was concluded to form a protective barrier around the sensirive fibers at the time of closure of the lens vesicle, confirming the earlier hypothesis and clinical findings.

Point-of-care testing of group A streptococcal antigen: performance evaluated by external quality assessment.

The purpose of this study was to evaluate the overall performance of rapid antigen detection (RAD) in group A streptococcus (GAS) in Finland by using the results of external quality assurance (EQA) samples. We also compared the performance of laboratory professionals to that of nursing professionals. Around 22,800 EQA results among a total of 383 laboratories and physician's offices were analysed. Vocational data on the personnel who carried out the tests were available for 10,088 EQA samples, 7,428 of which were tested by laboratory technicians and 2,531 by nursing staff. The best overall performance was found with GAS-negative samples: 99% of the reports were correct. In contrast, the overall performance was only 76% when the samples were weakly positive for GAS antigen. The laboratory technicians performed statistically significantly better than the nursing staff, with both strongly positive (correct results 98.9% vs. 95.1%, respectively; p<0.001) and weakly positive (79.3% vs. 65.3%, respectively; p<0.001) samples. With negative samples, no difference in performance between the laboratory and nursing staff was found (99.5% vs. 99.0%, respectively). The professional skills of the person performing the RAD test for GAS have a major impact on the sensitivity of the test. Based on the results of this study, we suggest that EQA-like artificial specimens could be used as a tool to improve and validate the quality of RAD testing in individual testing sites.

A prospective study of the role of coxsackie B and other enterovirus infections in the pathogenesis of IDDM. Childhood Diabetes in Finland (DiMe) Study Group.

Coxsackievirus B infections have been associated with clinical manifestation of insulin-dependent diabetes mellitus (IDDM) in several studies, but their initiating role in the slowly progressing beta-cell damage is not known. This is the first prospective study designed to assess the role of coxsackie B and other enterovirus infections in the induction and acceleration of this process. Three separate series were studied: 1) an intrauterine exposure series comprising 96 pregnant mothers whose children subsequently manifested IDDM and 96 control mothers whose children remained nondiabetic; 2) a cohort of 22 initially unaffected siblings of diabetic children who were followed until they developed clinical IDDM (mean observation time, 29 months) and 110 control siblings who remained nondiabetic; 3) a case-control series comprising 90 children with newly diagnosed IDDM and 90 control subjects. Enterovirus infections were identified on the basis of significant increases in serum IgG, IgM, or IgA class antibodies against a panel of enterovirus antigens (capture radioimmunoassay). Enterovirus antibodies were significantly elevated in pregnant mothers whose children subsequently manifested IDDM, particularly in cases in which IDDM appeared at a very young age, before the age of 3 years (P < 0.005). Serologically verified enterovirus infections were almost two times more frequent in siblings who developed clinical IDDM than in siblings who remained nondiabetic (mean, 1.0 vs. 0.6 infections/follow-up year; P < 0.001). This difference was seen both close to the diagnosis of IDDM and several years before diagnosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Enrichment of dendritic cells from human peripheral blood.

A simplified method is described for purification of dendritic cells from human peripheral blood. The method is based on depletion of phagocytes with carbonyl iron and magnet, followed by centrifugation of nonphagocytic cells on Percoll and elimination of contaminating T lymphocytes, B lymphocytes, natural killer cells, and monocytes from the low-density cell fraction by treatment with monoclonal antibodies and complement. The purity of enriched dendritic cells was about 80% and these cells represented 0.2% of the starting mononuclear cell population. Dendritic cells were potent autologous and allogeneic stimulators in mixed leukocyte cultures.

HIV-1 genetic subtype A/B recombinant strain causing an explosive epidemic in injecting drug users in Kaliningrad.

OBJECTIVES: To investigate the molecular epidemiology and genetic structure of the virus strain(s) causing an outbreak of HIV-1 infection in the Kaliningrad province of the Russian Federation and to investigate the relationship of this outbreak to some other emerging HIV-1 epidemics in the countries of the former Soviet Union. DESIGN: A molecular epidemiological investigation was conducted in the city of Kaliningrad amongst individuals recently diagnosed as HIV-1-positive. Samples were also collected from neighbouring Lithuania and from the Ukraine. METHODS: Incident and population data was collected from official health statistics in Kaliningrad. A standardized questionnaire was administered to newly diagnosed individuals to assess risk factors for HIV-1 infection. For genotyping, two regions of the virus (env C2-V3 and gag NCp7) were directly sequenced. RESULTS: The number of newly diagnosed individuals testing seropositive for HIV-1 infection in Kaliningrad rose from less than one per month to more than 100 per month during the period of July-October 1996. A total of 1335 new infections were identified between 1 July 1996 and 30 June 1997. The main reported risk factor for HIV-1 infection (80%) was injecting drug use, in particular with a locally produced opiate. Sequence analysis of patient viruses in Kaliningrad (n = 50) showed that the epidemic was caused by a highly homogenous HIV-1 strain, recombinant between the genetic subtypes A and B. Comparison with subtype A strains prevalent amongst injecting drug users (IDU) in the Ukraine showed that one of these strains was the direct subtype A parent of the epidemic A/B recombinant strain in Kaliningrad. CONCLUSIONS: The HIV-1 epidemic in Kaliningrad probably started from a single source, with rapid spread of the virus through the IDU population. The origin of the epidemic strain is a recombination event occurring between the subtype A strain virus prevalent among IDU in some southern CIS countries, and a subtype B strain of unknown origin.

Enrichment of human epidermal Langerhans cells by attachment to erythrocyte monolayers.

The present investigation introduces a method for purification of human epidermal Langerhans cells (LC). The method is based on the attachment of LC to IgG-coated sheep erythrocyte monolayers via their Fc receptors. To optimize the enrichment assay, several variables were tested. The best results were obtained when epidermal cells were centrifuged against erythrocyte monolayers; the purification procedure was performed at 4 degrees C in the presence of 5% fetal calf serum, using about 6 X 10(6) epidermal cells per erythrocyte plate (diameter 5 cm). The average purity of the recovered LC was 80.9% and LC-depleted fractions contained an average of 0.5% DR-positive cells. LC were able to enhance significantly leukoagglutinin- and purified protein derivative-induced T lymphocyte proliferation and leukocyte migration inhibitory factor production.

Langerhans cell- and T-lymphocyte functions in patients with atopic dermatitis with disseminated cutaneous herpes simplex virus infection.

We studied whether Langerhans cell (LC)- and T-lymphocyte functions of atopic dermatitis (AD) patients are impaired. Our study groups consisted of 6 patients with AD with previous disseminated herpes simplex virus infection (AD + HSV), 8 patients with ordinary AD, and 5 healthy subjects. Suction blisters were performed on abdominal skin and LC isolated on the basis of their attachment to IgG-coated erythrocyte monolayers. Antigen-presenting function of purified LC was studied by measuring the proliferation of HSV-stimulated T cells. Langerhans cells were also used to stimulate T cells in autologous mixed cell reaction (AMCR). In addition, the production of epidermal cell thymocyte-activating factor (ETAF) by crude epidermal cells was measured. The HSV-induced T-cell proliferation in AD + HSV and AD patients was comparable with that of controls. The AMCR responses of patients with AD + HSV and AD were clearly diminished when compared with healthy controls. Patients with AD also produced significantly less ETAF than controls. Our results suggest that HSV antigen-presenting function of LC from patients with AD + HSV seems to be intact. Defective AMCR may reflect an abnormality in autoregulation and generation of effector cells and this together with decreased ETAF production may have pathogenetic significance in AD.

Identification of antigenic components of Toxoplasma gondii by an immunoblotting technique.

Proteins of Toxoplasma gondii were separated by SDS-polyacrylamide gel electrophoresis with subsequent transfer to a nitrocellulose sheet by electrophoretic blotting. Immunologically reactive polypeptides were detected by human sera with previously known toxoplasma antibody levels. Heavy chain-specific, peroxidase-conjugated anti-human immunoglobulins were used as the indicator antibodies for the separate identification of IgG and IgM reactive polypeptides. IgG toxoplasma antibodies reacted with several antigens of Mr approximately 27 000-67 000, while toxoplasma-specific IgM seemed to detect only a few polypeptides. The Mr of 35 000 for the dominating IgM reactive polypeptide was observed.

CSF oligoclonal bands, immunoglobulins, and viral antibodies in progressive myoclonus epilepsy.

We studied CSF and serum samples from 16 patients with progressive myoclonus epilepsy (PME). These patients had juvenile-onset PME with evidence of autosomal recessive inheritance and no Lafora bodies. Twelve of the 16 patients with PME had immunologic abnormalities. Oligoclonal gamma bands were seen in six of the eight patients from whom sufficient CSF was available. The CSF albumin and serum/CSF albumin ratios were normal in all 16 patients, indicating the presence of intact blood-brain barriers. Six of the 16 patients showed increased CSF IgG levels and five had an increased CNS IgG synthesis. All patients had normal serum and CSF IgM and IgA levels. Three patients, all with bands, had reduced measles and/or vaccinia serum/CSF antibody ratios. The findings suggest altered immune response of the CNS of some patients with PME apparently caused by nonspecific immunostimulation.

Measles and canine distemper antibody. Presence in sera from patients with multiple sclerosis and matched control subjects.

Antibody to measles virus and canine distemper virus (CDV) was demonstrated in sera from patients with multiple sclerosis (MS) and from carefully matched control subjects. Elevated measles and CDV antibody titers were found in patients with MS when compared with the matched control subjects. The correlation between the measles and CDV antibody titers was quite high, suggesting that the antibody levels between the two viruses are very closely related. Based on the results of our study and a review of the literature, our conclusion is that the CDV antibody levels in patients with MS and matched control subjects are associated with occurrence of measles virus antibodies.

Coronavirus antibodies in sera from patients with multiple sclerosis and matched controls.

Sera from patients with multiple sclerosis and carefully matched controls were tested for antibodies to three strains of coronavirus. There was no significant difference in the levels of antibody in the patients vs the controls. We conclude that unless the strains of coronaviruses recently reported to have been isolated from patients with multiple sclerosis express important serological differences from those used in these studies, coronaviruses are not associated with the cause of multiple sclerosis.

Viral antibodies in twins with multiple sclerosis.

Viral antibodies to measles, rubella, corona, vaccinia, and mumps viruses in serum and CSF (and to Epstein-Barr virus in serum only) were studied in 24 twin pairs, both discordant and concordant for clinical MS. In pairs, CSF antibody titers for rubella in MS monozygotic and dizygotic twins and for vaccinia in dizygotic twins were higher than for unaffected twins. Increased CSF titers among MS twins existed for measles, rubella, and vaccinia when pairing was ignored. Among MS twins, serum rubella and measles and CSF measles antibody titers, and CSF:serum ratios for measles virus, were higher in those who were DW2 positive.

Lymphocyte bacterial rosette test: methodological details and effect of metabolic inhibitors and divalent cations.

Lymphocytes bind certain bacteria. This property has been utilized in the lymphocyte bacterial rosette assay to identify T and B cell subsets. Here we determined the optimum conditions for the assay, studied the effect of metabolic inhibitors and divalent cations and compared bacterial rosette-forming lymphocyte subpopulations with those defined with monoclonal antibodies. The strains used were Brucella melitensis, Bacillus subtilis, Staphylococcus aureus and Escherichia coli. Optimum attachment was obtained at 4 degrees C in 6% BSA with ultrasonicated bacteria. Pretreatment of lymphocytes with the microfilament-disruptive drug cytochalasin B suppressed the binding of bacteria, whereas colchicine (inhibitor of microtubules), puromycin (inhibitor of translation), sodium azide (inhibitor of oxidative phosphorylation) and 2-deoxyglucose (inhibitor of glycolysis) had no effect. Divalent cations were required for the attachment of bacteria. B. melitensis bound to DR-positive cells, whereas the other bacterial strains rosetted OKT4- OKT8- and DR-positive cells without exhibiting helper or suppressor T cell or B lymphocyte specificity.

Detection of Mycoplasma hominis antigen in clinical specimens by using a four-layer modification of enzyme immunoassay (EIA).

A 4-layer modification of enzyme immunoassay (EIA) was developed for the detection of Mycoplasma hominis antigen in clinical specimens. Microtiter plates were sensitized with rabbit anti-mycoplasma immunoglobulin, guinea pig anti-mycoplasma immunoglobulin was used as the secondary antibody, and horseradish peroxidase-conjugated anti-guinea pig immunoglobulin was used as the indicator antibody. The specificity of the assay was confirmed by using guinea pig immunoglobulins from preimmunization sera. The sensitivity of the assay is down to 10 ng/ml of antigen protein. Marked cross-reactivity was demonstrated for different strains within the species M. hominis, whereas the other genital mycoplasma species tested showed no reactivity in the assay. A comparison was made of EIA and conventional culture of vaginal specimens from 24 women. All 6 specimens positive by culture were also positive for M. hominis antigen by EIA. Antigen detection by EIA is a sensitive, rapid and simple method for the detection of M. hominis in clinical specimens.

An AB recombinant and its parental HIV type 1 strains in the area of the former Soviet Union: low requirements for sequence identity in recombination. UNAIDS Virus Isolation Network.

In the former Soviet Union (SU) increasing numbers of HIV-1 infections among injecting drug users (IDU) have been reported, especially in the Ukraine. The main subtype transmitted among the IDUs seems to be subtype A, but limited numbers of subtype B cases have also been reported. In Kaliningrad, Russia, an AB recombinant strain was earlier shown to be responsible for the local outbreak. Here we describe the genetic relationship of HIV-1 strains circulating among IDUs in the former SU. For subtype A and the AB recombinant strains nearly full-length genomes were sequenced, and for one subtype B strain the entire envelope gene was cloned. The relationship between the AB recombinant strain and the subtype A and subtype B strains and the mosaic structure of the recombinant was studied by phylogenetic analysis. Ukrainian A and B strains were shown to be the probable parental viruses of the Kaliningrad AB recombinant strain. In the envelope gene the recombination breakpoint could also be precisely mapped to a region of similarity of only 14 base pairs. This suggests that only short stretches of absolute sequence identity may be needed for efficient RNA recombination between HIV-1 subtypes.

Full-length sequence of an ethiopian human immunodeficiency virus type 1 (HIV-1) isolate of genetic subtype C.

Genetic subtype C of the human immunodeficiency virus type-1 (HIV-1) has established foci of infection in India and in at least eight African countries, and is expected to contribute significantly to the global pandemic. Here we report the first almost full-length sequence of a subtype C HIV-1 from Ethiopia. Clone C2220, 9031 nt in length, was derived by long PCR amplification of proviral DNA from virus cultured on primary peripheral blood mononuclear cells, and contains all but 74 nt of the unique sequence information of the HIV-1 genome. This clone resembles HIV-1 isolates of subtypes A, B, and D in its genome organization with one notable exception: the core promoter contains not two, but three potential binding sites for the transcription factor NF-kB. The extra NF-kB site was found in all other Ethiopian strains analyzed, as well as in subtype C viruses from Zambia, suggesting it is typical for the C-subtype of HIV-1. The phylogenetic relationship of C2220 to other HIV-1 isolates is also presented. Subtype C viruses circulating in Ethiopia exhibit the low interisolate diversity typical of other, newly established HIV-1 epidemics, and C2220 is both representative of Ethiopian subtype C viruses and a suitable prototype for the development of vaccines against HIV-1 subtype C.

PIP: Foci of HIV-1 subtype C infection exist in India and at least eight African countries. HIV-1 subtype C will likely contribute significant numbers of cases to the global AIDS pandemic. The first almost full-length sequence of a subtype C HIV-1 from Ethiopia is presented. Clone C2220, 9031 nucleotides long, was derived by long polymerase chain reaction amplification of proviral DNA from virus cultured on primary peripheral blood mononuclear cells and contains all but 74 nucleotides of the unique sequence information of the HIV-1 genome. The clone's genome organization resembles HIV-1 isolates of subtypes A, B, and D except that its core promoter contains three rather than two potential binding sites for transcription factor NF-kB. The extra NF-kB site was found in all other Ethiopian strains analyzed, as well as in subtype C viruses from Zambia, suggesting that the configuration is typical for subtype C HIV-1. The phylogenetic relationship of C2220 to other HIV-1 isolates is also presented.

Collaboration between human blood dendritic cells and monocytes in antigen presentation.

We compared human blood dendritic cells and monocytes for their capacity to produce secreted and membrane interleukin 1 (IL-1), stimulate mixed leukocyte reaction (MLR) and augment microbial antigen-induced T lymphocyte proliferation. Our enriched dendritic cell and monocyte fractions contained greater than 80% and greater than 93% dendritic cells and monocytes, respectively. Monocytes produced about ten times higher amounts of membrane and secreted IL-1 than dendritic cells, which in turn were more potent in presenting HLA-DR antigens in MLR. Both accessory cell types presented purified protein derivative of tuberculin (PPD) equally well, whereas monocytes were better with fixed Bacillus Calmette Guérin (BCG) bacteria. Processing of BCG was chloroquine-sensitive. Coculture experiments suggested that there was collaboration or synergy between dendritic cells and monocytes in antigen processing and presentation.

Defective HLA class II expression in monocytes of type 1 diabetic patients. The Childhood Diabetes in Finland Study Group.

Activation of T-helper cells is modulated by the intensity of HLA class II expression on antigen-presenting cells. We evaluated whether any abnormalities could be found in the expression of HLA-DR and -DQ molecules on monocytes in type 1 diabetic subjects. DR and DQ molecules were induced by human recombinant interferon-gamma on cultured peripheral blood monocytes obtained from children with type 1 diabetes (N = 28), their siblings (N = 18) and unrelated healthy controls (N = 21). The response in DQ induction varied considerably between different individuals, but the average responsiveness was significantly lower in patients compared to siblings and unrelated controls. In addition to the diabetic subjects deficient DQ induction was also observed in three siblings. One of them had high levels of islet cell antibodies and presented with diabetes 6 months later, and another had active rheumatoid arthritis. The response in DR induction was also slightly lower in patients than in siblings, but did not differ from that in unrelated controls. The results suggest abnormalities in the regulation of HLA class II expression in type 1 diabetic subjects possibly reflecting the ongoing autoimmune process.

Decreased antibody reactivity to Epstein-Barr virus capsid antigen in type 1 (insulin-dependent) diabetes mellitus.

In this study, antibody levels to Epstein-Barr virus (EBV) capsid antigen (VCA) and EBV early antigens (EA) were analysed by enzyme immunoassay in 54 newly diagnosed type 1 diabetic children and in matched controls. The patients had significantly lower EBV VCA IgG-class antibody levels (p less than 0.02). This was true particularly in young patients and in boys (p less than 0.005). VCA IgA-class antibody levels were also decreased in young patients (p less than 0.02). VCA IgM-class antibodies were observed in two of the patients only. IgG- and IgA-class antibodies to EBV EA or rubella virus antigen showed no differences between patients and controls. The results suggest that EBV infections coincide with the onset of clinical diabetes relatively rarely. However, the abnormally low antibody response to EBV VCA in diabetic children suggests abnormalities in the EBV-specific immune response.

Evolution of the HIV epidemic in Kaliningrad, Russia.

BACKGROUND: Our earlier epidemiological and virological analysis made in 1997 suggested that in the Kaliningrad region of Russia a rapidly spreading human immunodeficiency virus (HIV)-epidemic among injecting drug users had recently started and that it was caused by an unusual A/B subtype recombinant strain of HIV. Furthermore, it was evident that the societal and health care structures necessary to combat the spread of the infection were not well developed. Since June 1996 more than 2400 HIV-infections have been detected in the region with a population of less than 1 million. Here we report the current situation concerning the epidemic and its risk factors. The information is based on information collected during several visits and from written reports. OBJECTIVES: Whereas almost all cases in the earliest phase of the epidemic have occurred among injecting drug users (IDU), sexual transmission may soon become more common and spread the epidemic into the non-IDU population. We describe here the recent evolution of the epidemic and the various risk factors that seem to contribute to the outbreak. We also describe the current resources that are used for prevention. STUDY DESIGN: Information complementing earlier studies were collected during visits to Kaliningrad from direct observations, interviews with local authorities and official bulletins and written reports by local and national experts. CONCLUSIONS: Local resource building with the aid of international help is urgently needed to alleviate the forthcoming crisis due to clinical consequences of AIDS. Both prevention and patient management require resources that are not available at present. Also, more virological studies should be undertaken to identify the present and future pattern of the epidemic.