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G Wadell

Publications and source records attributed to G Wadell.

At least 91 records · Page 5Linked to original sources
PubMed1992

Improved detection of HIV-2 DNA in clinical samples using a nested primer-based polymerase chain reaction.

A two-step polymerase chain reaction (PCR), with four double (nested) primer pairs, used for the detection of HIV-2 in clinical samples is described. With these four nested primer pairs we could detect HIV-2 DNA in 17 of 17 virus isolates and in blood mononuclear cell samples from 31 of 37 (83.7%) seropositive individuals after ethidium bromide staining of the amplified DNA. The nested primer PCR was also compared with a single primer pair-based PCR followed by hybridization. The sensitivities of the two methods were almost equal, but the nested primer PCR offered obvious technical advantages.

Adolescent↗
PubMed1991

Detection of transforming gene regions of human papillomavirus type 16 in cervical dysplasias by the polymerase chain reaction.

In a study of 29 cases of histologically confirmed, characterized colposcopically and cytologically, cervical intraepithelial neoplasias 48.3% (14/29) of biopsies were positive for human papillomavirus (HPV) type 16 DNA by polymerase chain reaction. We used two oligonucleotide primer pairs (position 215-514 and 606-805) flanking a 300 and a 199 base pair fragment from the early 6 (E6) and early 7 (E7) genes. The results were concordant both with the E6 and with the E7 regions. Of the amplified products 85.7% (12/14) could be confirmed; these carried 16 specific sequences by Southern blot hybridization. HPV 16 DNA was present in 6.7% (2/30) of the colposcopically directed cytologically normal matched control samples using the same methods.

Adult↗
PubMed1991

Oligonucleotide primers for DNA amplification of the early regions 1, 6, and 7 from human papillomavirus types 6, 11, 16, 18, 31, and 33.

Human papillomavirus (HPV) type-specific sequences required for polymerase chain reaction (PCR) mediated amplification of HPV DNA sequences are presented. One primer pair within the E1 open reading frame (ORF) was shared by HPV 6, HPV 11, HPV 16, and HPV 31, whereas the other primer pair within the E1 ORF was specific for HPV 16. Eight primer pairs from the E6 and E7 ORFs specifically detected HPV 6, HPV 16, HPV 18, and HPV 33 sequences. This system has been used for detection of HPV DNA in biopsies, cytological smears and sections of formalin-fixed tissues.

Base Sequence↗
PubMed1991

Analysis of transforming gene regions of human papillomavirus type 16 in normal cervical smears.

Exfoliated cells from the uterine cervix of 102 Hungarian women with no cytological abnormality were screened using the polymerase chain reaction (PCR) for human papillomavirus (HPV) type 16 infection. Twenty-nine patients with histologically confirmed cervical intraepithelial neoplasia (CIN) served as reference cases. PCR was performed with 2 different HPV 16 specific oligonucleotide primer pairs flanking a 300 and a 200 base-pair fragment from the early 6 (E6) and early 7 (E7) genes, position 215-514 and 605-805. The specimens exhibited the same proportions of type 16 sequences specific for the tested regions. 8.8% (9/102) of normal samples showed amplification for HPV type 16 E6 and E7 regions, while 48.3% (14/29) of CIN biopsies were positive for the same gene sequences.

Cervix Uteri↗
PubMed1991

Vaccine protection against HIV-2 infection in cynomolgus monkeys.

The aim of this study was to determine if protection against an infectious human immunodeficiency virus type 2 (HIV-2) challenge could be obtained in cynomolgus macaques by active immunization using whole killed virus vaccine. Four monkeys were immunized with killed HIV-2SBL-6669, two of them with five intramuscular (im) injections of viral preparation containing 100 or 300 micrograms protein emulsified in incomplete Freund's adjuvant (IFA) and the two remaining received four im injections of 25-50 micrograms viral protein in iscoms. Each of the four vaccinated cynomolgus monkeys, along with four unvaccinated controls, were challenged intravenously two weeks after the last booster with approximately 100 animal infectious doses (ID50) of live HIV-2SBL-6669. All four immunized monkeys developed antibodies to HIV-2 envelope and core proteins before challenge exposure to HIV-2, but only the two animals vaccinated with virus in IFA developed detectable neutralizing antibodies. The two monkeys immunized with killed virus in IFA have shown no evidence of infection nine months after challenge with live virus. When blood and lymph node cells from these animals were transfused into naive cynomolgus monkeys, the recipients remained free of infection. In contrast, virus was recovered repeatedly in all nonimmunized animals and in the two animals immunized with iscom-associated viral antigens, which had a low content of envelope gp125 antigen. The demonstration of vaccine-induced protection against HIV-2 in a nonhuman primate raises hope for effective immunization against HIV infections in humans as well.

Animals↗
PubMed1991

Genome analysis of adenovirus type 31 strains from immunocompromised and immunocompetent patients.

Adenovirus type 31 (Ad31) was isolated from 15 immunocompromised patients in 12 of whom seroconversion was also recorded. Ad31 infection has a substantial clinical relevance since 8 of 10 with lower respiratory tract infection and 4 of 4 with hepatitis died. Therefore, Ad31 isolates from immunocompetent and immunodeficient hosts were compared by restriction endonuclease analysis. Nine genome types were identified among the 79 Ad31 isolates. Pairwise comparison of comigrating restriction fragments indicated that the genome types could be divided into three genomic clusters. Several Ad31 genome types were isolated from immunocompromised patients, but no highly virulent genome type could be found. A genome type was identified in a child with severe combined immunodeficiency who originally was infected with another genome type. This observation is suggested to have evolutionary implications.

Adenovirus Infections, Human↗
PubMed1991

Genetic relationship between thirteen genome types of adenovirus 11, 34, and 35 with different tropisms.

Eleven genome types of adenovirus serotype 11 (Ad11) were identified among 20 strains isolated from healthy pregnant women and patients with urinary tract infections, respiratory tract infections, or pharyngoconjunctival fever by use of 13 restriction endonucleases: BamHI, BclI, BglI, BglII, BstEII, EcoRI, HindIII, HpaI, PstI, SalI, SmaI, XbaI, and XhoI. All genome types could be grouped into three genomic clusters according to their genetic homology expressed as pairwise comigrating restriction fragments. The genome types within a genomic cluster were very closely related. They shared on an average pairwise comigrating restriction fragments of 91.6-97.7%. The Ad11 strains of genomic clusters 1 and 3 were isolated from urine, whereas all the Ad11 strains isolated from the respiratory tract were identified as members of the genomic cluster 2. One genome type of Ad34 and one genome type of Ad35 were identified from a hemorrhagic cystitis patient and an organ transplant recipient, respectively. Both were closely related to Ad11. The genome type of Ad35 could be located in the Ad11 genomic cluster 1.

Adenoviruses, Human↗
PubMed1991

Selection of primers of optimal sensitivity for the detection of HIV-1 from Africa and Europe by polymerase chain reaction.

In order to facilitate the detection of integrated HIV-1 proviral DNA from African as well as European patients, four new primer pairs for use in the polymerase chain reaction (PCR), localised in the gag, pol, vif and env genes of HIV-1, were constructed. The primer pairs were compared to all accessible HIV-1 sequences from African and European isolates and to some of the earlier published and most commonly used primer pairs. HIV-1 DNA was detected in blood drawn from 13 out of 13 individuals infected in Africa, in three out of three Tanzanian HIV-1 isolates and in three out of three asymptomatic Swedes infected in Europe. The new selection of primer pairs can be used as an alternative to enhance the detection of HIV-1 of different origins.

Acquired Immunodeficiency Syndrome↗
PubMed1990

[PCR--a highly sensitive method for identification and study of virus infections].

Viral infections can be diagnosed with using methods of molecular biology. Provided at least part of the gene sequence is known for the virus under consideration, the PCR (polymerase chain reaction) technique can be used to identify such viruses as HIV, papilloma virus, cytomegalovirus, herpes simplex virus, enterovirus, the hepatitis viruses and diarrhoeagenic viruses. Developments in this field have occurred with unprecedented rapidity. The review is primarily focused on fields where the techniques of molecular biology have crucially contributed to our knowledge of uiral pathogenesis.

Cytomegalovirus Infections↗
PubMed1990

Enteric adenoviruses.

Human adenoviruses are classified into 47 serotypes and six subgenera (A-F) with different tropisms. In recent years adenovirus type 40 (Ad40) and 41 (Ad41) of subgenus F have been shown to be causative agents in enteric infections, which is second in importance only to rotaviruses as a cause of infantile gastroenteritis. Infection with EAds occurs worldwide and has been associated with 4-17% of cases of diarrhoea in children. AD40 and Ad41 primarily affect young children less than 2 years of age and occur throughout the year. The clinical characteristics include watery diarrhoea accompanied by vomiting, low grade fever and mild dehydration. A distinct feature of EAds infection is the protracted diarrhoea (mean 8.6 and 12.2 days for Ad40 and Ad41, respectively). Respiratory symptoms are infrequent. Serotypes Ad40 and Ad41 differ from all other (established) adenoviruses by being unable to replicate in conventional cell cultures. These fastidious viruses only grow in selected cell lines, 293 cells being the most commonly used. In spite of the difficulty of isolating Ad40 and Ad41, they can be directly identified and typed by ELISA and solid-phase immune electron microscopy. The amount of viral DNA in stool specimens is sufficient for identification by DNA restriction and dot-blot assays. The recent development of highly sensitive and specific monoclonal antibody-based ELISAs enable accurate diagnosis of adenovirus gastroenteritis in routine work and make possible the evaluation of the role of the enteric adenoviruses in diarrhoeal disease in the developing countries.

Adenoviridae↗
PubMed1990

Polymerase chain reaction for detection of adenoviruses in stool samples.

The usefulness of the polymerase chain reaction (PCR) method for diagnosing adenovirus infections was investigated. Several primers, including primers specific for the hexon-coding region and for enteric adenovirus types 40 and 41, were evaluated. The PCR method was validated against cell culturing in routine diagnostic work and against restriction enzyme analysis of viral DNA. Sixty diagnostic specimens were selected for evaluation by the PCR method. Twenty of the 60 specimens were found positive on the basis of cytopathic effects and latex agglutination (Adenolex [Orion Diagnostica, Helsinki, Finland]), and 16 were identified and typed as adenoviruses by polyacrylamide gel electrophoresis. PCR was performed on all 60 specimens in parallel directly on diluted stool samples and on viral DNA extracted from cells inoculated with the same stool samples. When the general hexon primers were used 51 of the 60 specimens from infected cell cultures were found positive by PCR, whereas only 13 specimens were found positive when PCR was performed directly on stool samples. With the use of selective primers for enteric adenoviruses 16 of the 60 cell cultures were found to exhibit amplification products by PCR, whereas 4 were detected in stool samples. None of the 60 specimens were found positive by PCR when an adenovirus type 40-specific primer pair was used. PCR was found to be a fast, sensitive, and reliable method for the detection of adenoviruses in diarrheal disease, provided the amplifications were performed directly on diluted stool samples.

Adenovirus Infections, Human↗
PubMed1990

Detection of human papilloma virus in women referred for colposcopy. A comparison between different diagnostic methods.

Various methods presently available for the diagnosis of genital Human Papilloma Virus (HPV) were compared regarding their sensitivity in women referred for specific diagnosis and treatment because of atypical Pap smears or clinically suspected neoplasia. Colposcopic examination was performed in all cases. In addition to taking a second Pap smear, cell suspensions were made from 105 women and analysed by the Filter In Situ Hybridization (FISH) technique and tested for HPV 6 + 11 and HPV 16 + 18 + 31. The FISH technique was also used for the possible detection of HPV-DNA in a reference material comprising 119 apparently healthy women with normal Pap smears. Colposcopically directed cervical biopsies in altogether 196 specimens were obtained from 155 women for histopathological examination and also for the detection of HPV-DNA by the Southern blot hybridization technique. These specimens were tested for the presence of HPV 6, 11, 16, 18, 31 and 33. Three per cent of the women with and 34% without cytological signs of HPV in Pap smears had cervical intraepithelial neoplasia (CIN) III according to histopatology. CIN III was present in 35% of biopsies with and 59% of biopsies without histological signs of HPV in the biopsies. Altogether 46% of the women were HPV-DNA positive. Of the women analysed by Southern blot, 39% were HPV-DNA positive. Of the samples analysed by FISH, 27% with atypical cells were HPV-DNA positive, compared with 11% of the samples from reference women with normal cytology.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Adenovirus type 7 infections in children in New South Wales, Australia.

This study describes our experience of adenovirus type 7 infection in children in New South Wales, Australia. Some aspects of the epidemiology of the infection are also recorded. A community outbreak, a hospital-ward outbreak, sporadic cases, and data from a centralised registry are described. Results of genome-type identification using restriction endonucleases are given. Adenovirus type 7b infection was associated with significant mortality and points to the need, previously expressed, for an adequate vaccine for high-risk infants. Continued surveillance of adenovirus type 7 infections worldwide is necessary to identify genome types so that appropriate vaccines can be developed.

Adenoviridae Infections↗
PubMed1989

Animal model of rotavirus infection in rabbits--protection obtained without shedding of viral antigen.

A small animal model was developed in order to investigate the pathogenesis and immunology of rotavirus infections and to study the interaction of different virus strains. Seronegative rabbits of the breed French Lop were used. Two rabbit rotavirus strains, belonging to the same serotype, were used: 82/311 F and R-2, both isolated during diarrhoeal outbreaks in commercial rabbitries. The animals were inoculated orally. The viral shedding and the serological response was monitored by ELISA. Initially six weeks old kits were given four different doses of strain R-2. With doses ranging from 1 x 10(3) to 1 x 10(6) TCID50 all animals seroconverted, but for the lowest dose no viral excretion could be detected. No clinical symptoms were observed. Subsequently the age periods during which the animals were susceptible to the strain R-2 was investigated. The rabbits seroconverted and shed rotavirus antigen, independent of age of six or 22 weeks. None of the animals had diarrhoea. Administration of strain 82/311 F did not result in viral shedding, independently of dose, but all the animals seroconverted. It was also shown for the strain R-2 that when challenging with the same strain four weeks post inoculation that the animals were protected; no viral shedding was detected at the second infection. Strain 82/311 F gave protection against R-2 when the rabbits were challenged four weeks post inoculation.

Aging↗
PubMed1989

Papilloma virus infection of the vulva.

Analyses of the possible presence of human papilloma virus (HPV) DNA were performed on 84 biopsies from 50 women with clinically and histopathologically suspected HPV infection of the vulva. The colposcopic criteria for inclusion in the study were: acetowhite flat lesions with or without fissures and/or diffuse hyperplastic mucosa with a granulated or filamental surface. Directed biopsies for histopathology and DNA hybridization (dot-blot and Southern-blot) were taken. All women had histopathological evidence of HPV infection. Twelve women had cervical and/or vulvar neoplasia. HPV DNA could be demonstrated in the vulvar biopsies from 24 women; 13 women had HPV 16, 3 had HPV 18, HPV 31 and HPV 33, respectively. In addition, 10 biopsies contained HPV DNA of unknown types. Fifty-five percent of granulated and filamental lesions and 43% of flat lesions with or without fissures were positive for HPV DNA. 34 women had one or more of the following symptoms: itching, burning, dyspareunia, discharge, fissures, dryness and dysuria. Papillomavirus vulvitis is a sexually transmitted disease which may cause recalcitrant symptoms and/or concomitant neoplasia. It is thus important to recognize the different symptoms and signs of this disease.

Adult↗
PubMed1989

Long-term persistence of false positive antibody reactivity in HIV western blot testing of sera from a healthy blood donor.

HIV-Western blot (WB) testing of sequential sera from a blood donor revealed identical bands in the p24 and p55 positions. Additional testing using indirect immunofluorescence antibody technique, radioimmunoprecipitation assay and an HIV p24 antigen immunoassay were negative. During a 5-year follow-up period the blood donor has remained apparently healthy and no signs of disease have developed. We conclude that sera from this blood donor show a false positive HIV WB reactivity. The nature of this reactivity remains obscure but has practical implications for the routine HIV screening of blood donors.

Adult↗