Biomedical subjects

G Wadell

Publications and source records attributed to G Wadell.

At least 73 records · Page 4Linked to original sources

PubMed1994

Simple procedure for discrimination and typing of enteric adenoviruses after detection by polymerase chain reaction.

A procedure was developed for specific discrimination and typing of the enteric human adenoviruses, Ad40 and Ad41, after polymerase chain reaction (PCR) amplification of a sequence in the hexon gene highly conserved among all 47 serotypes recognised. By Taq I restriction of the 300 bp amplimers, subgenus F DNA could be discriminated from DNAs of adenoviruses belonging to all other subgenera. Discrimination between Ad40 and Ad41 was subsequently achieved by cleavage with either Cfo I, HinP I, Mae III, Mvn I, and/or Rsa I. Thus, PCR detection of viral DNA combined with restriction analysis of amplified products provides a valuable tool for use in epidemiological studies of diarrhoea of adenoviral aetiology.

Adenoviridae Infections↗

PubMed1994

Detection of adenoviruses and enteroviruses in polluted waters by nested PCR amplification.

A procedure has been developed for the rapid detection of enteroviruses and adenoviruses in environmental samples. Several systems for virus concentration and extraction of nucleic acid were tested by adding adenovirus type 2 and poliovirus type 1 to different sewage samples. The most promising method for virus recovery involved the concentration of viruses by centrifugation and elution of the virus pellets by treatment with 0.25 N glycine buffer, pH 9.5. Nucleic acid extraction by adsorption of RNA and DNA to silica particles was the most efficient. One aliquot of the extracted nucleic acids was used for a nested two-step PCR, with specific primers for all adenoviruses; and another aliquot was used to synthesize cDNA for a nested two-step PCR with specific primers for further detection of seeded polioviruses or all enteroviruses in the river water and sewage samples. The specificity and sensitivity were evaluated, and 24 different enterovirus strains and the 47 human adenovirus serotypes were recognized by the primers used. The sensitivity was estimated to be between 1 and 10 virus particles for each of the species tested. Twenty-five samples of sewage and polluted river water were analyzed and showed a much higher number of positive isolates by nested PCR than by tissue culture analysis. The PCR-based detection of enteroviruses and adenoviruses shows good results as an indicator of possible viral contamination in environmental wastewater.

Adenoviridae↗

PubMed1994

Elevated levels of total and Puumala virus-specific immunoglobulin E in the Scandinavian type of hemorrhagic fever with renal syndrome.

In a previous study, it was reported that the total immunoglobulin E (IgE) level was increased in patients with hemorrhagic fever with renal syndrome (HFRS). The aim of the present study was to investigate whether specific IgE is synthesized during the course of the disease. For this purpose, an epsilon-capture enzyme-linked immunosorbent assay was developed. A total of 72 patients with HFRS caused by Puumala virus were studied. Three different control groups were included: 20 blood donors, 20 patients with other viral diseases (influenza A and B virus, acute Epstein-Barr virus, and acute cytomegalovirus infections), and 5 subjects with high levels of total IgE (median, 1,070 kU/liter; range, 773 to 5,740 kU/liter). The levels of total IgE were significantly higher during the acute phase of HFRS than those of blood donors (P < 0.01) and of patients with other viral diseases (P < 0.001). All patients developed a specific IgE response (median, 55 arbitrary units; range 24 to 123 arbitrary units) in the acute phase of the disease, whereas in the different control groups no specific IgE was detectable. Both total and specific IgE levels decreased during convalescence compared with those during the acute phase of HFRS (P < 0.001 and P < 0.001, respectively). In conclusion, we have shown that both total and specific IgE levels are increased in patients with HFRS compared with levels in patients with other viral diseases. The possible pathogenetic role of the specific IgE response in HFRS is discussed.

Acute Disease↗

PubMed1994

Adenovirus infection enhances in vitro adherence of Streptococcus pneumoniae.

Viruses are thought to facilitate bacterial infections of the respiratory tract, but the mechanisms are poorly understood. The present study analyzed the effect of adenovirus on bacterial adherence to human respiratory tract epithelial cells. The human lung carcinoma cell line A549 was infected with adenovirus of types 1, 2, 3, 4, 5, and 9. At a multiplicity of infection of 75 particles per cell, cytopathic effects occurred in 75 to 100% of the cells within 48 h. The virus-infected cells were harvested at various times after infection and analyzed for the ability to bind strains of Haemophilus influenzae and Streptococcus pneumoniae. Adenovirus (types 1, 2, 3, and 5) commonly causing respiratory tract infections increased the binding of adherent S. pneumoniae strains to the cells. This effect was not seen for other adenovirus types. Adenovirus infection did not change the adherence of cells of poorly adhering strains of S. pneumoniae or H. influenzae. The increase in adherence of S. pneumoniae could be inhibited by the DNA synthesis inhibitor cytosine arabinofuranoside, which is known to block the late phase of the adenovirus infection. When electron microscopy was used, there was no evidence that virus particles bound directly to bacteria. Adherence was not affected by pretreatment of the cells with virus particles or viral proteins. This suggested that adenovirus infection upregulated receptors for S. pneumoniae. The increased attachment may be one mechanism by which viruses precondition the respiratory mucosa for bacterial infection.

Adenoviridae↗

PubMed1994

Genome analysis of South American adenovirus strains of serotype 7 collected over a 7-year period.

DNA restriction analysis was carried out on a sample of 212 epidemiologically unrelated adenovirus (Ad) strains of serotype 7 isolated in Chile, Uruguay, and Argentina from nasopharyngeal aspirates of children with acute lower respiratory disease between 1984 and 1990. The identified genome types were Ad7b (n = 12), Ad7c (n = 21), and Ad7h (n = 179). The analysis of the occurrence of the three genome types throughout the study period revealed that Ad7c was the predominant virulent variant in 1984 and indicated that a shift to genome type 7h took place in 1986. Ad7b cocirculated with the other genomic variants at a relatively low frequence.

Adenoviridae Infections↗

PubMed1994

The absence of vaginal human papillomavirus 16 DNA in women who have not experienced sexual intercourse.

OBJECTIVE: To determine whether young women who have not experienced sexual intercourse may harbor genital human papillomavirus (HPV) infection in the vaginal-ectocervical mucosa. METHODS: We included 151 women, 10-25 years of age, attending two adolescent health care units (Stockholm and Uppsala) and one primary health care center (Umeå). The size of the hymenal orifice, use of tampons, and the habit of digital vaginal manipulation were registered. Samples of epithelial cells were collected from the vagina and analyzed for the presence of HPV using polymerase chain reaction. RESULTS: One hundred thirty of 154 samples contained an adequate number of cells. Two samples were HPV 6 DNA-positive. None were HPV 16 DNA-positive. None of the women had external genital warts. In 84%, the hymenal opening was 15 mm or less. Forty-eight percent of the women used tampons during periods. Fifty-four percent had inserted their own finger into the vagina and in 23%, a boyfriend's finger had penetrated the vagina. CONCLUSION: Human papillomavirus is rarely present vaginally in virginal women, even with the use of tampons or digital penetration.

Adolescent↗

PubMed1993

Hemagglutination properties and nucleotide sequence analysis of the fiber gene of adenovirus genome types 11p and 11a.

The fiber has been suggested to serve as the ligand between the adenovirus capsid and the host cell receptor. The two genome types, Ad11p and Ad11a, of adenovirus serotype 11 display different tropisms. The fiber amino acid sequences of the two genome types have been deduced from the 975 nucleotides that encoded a fiber polypeptide of 35,500 Da. The fiber consists of a tail, a shaft, and a knob region. The amino acids 44 to 140 form a typical shaft domain of six 15-residue repetitive motifs. Ten amino acids in the Ad11p fiber shaft were substituted in Ad11a. Five unpolar residues have been replaced by four polar and one unpolar amino acid. In the knob region, a total of 14 amino acid mismatches were noted between Ad11p and Ad11a. The amino acid sequence Asn-Asp-Glu at positions 283 to 285 in Ad11p was changed to Arg-Ala-Asp in Ad11a. The sequence Thr-Leu-Trp-Thr from positions 133 to 136 was conserved in all analyzed human and canine adenoviruses. The polypeptide at positions 235 to 244, Phe-Met-Pro-Ser-Thr-Thr-Ala-Tyr-Pro-Phe, probably contains a subgenus epitope, since it is conserved among subgenus B adenoviruses. Ad11p aggregated rhesus and vervet erythrocytes at 37 degrees, 22 degrees, and at 4 degrees, respectively, whereas Ad11a did not display hemagglutination under the same conditions. The complete fibers of Ad11p and Ad11a share an overall amino acid homology of 92.3%. The homology within the shaft and the knob region was 89.7 and 92.4%, respectively. These variable amino acids should be expected to be responsible for the differences in hemagglutination and tropism examplified by the persistent urinary tract infections caused by Ad11p and the acute respiratory tract infections caused by Ad11a.

Adenovirus E3 Proteins↗

PubMed1993

Genome type analysis of South American adenoviruses of subgenus C collected over a 7-year period.

A collection of 148 adenovirus strains of subgenus C collected in Argentina, Chile, and Uruguay were studied by restriction enzyme analysis of genomic DNA with endonucleases BamHI, BglII, BstEII, EcoRI, HindIII, KpnI, and SmaI. Only strains corresponding to serotypes 1, 2, and 5 were identified representing both already described and new genome types. The most frequently detected type was Ad 2 followed by Ad 1 and Ad 5. Three different genomic variants of both Ad 1 and Ad 5 were discriminated. Ad 2 with 9 genome types exhibited the greatest variability. Novel profiles emerged only in strains corresponding to this serotype by restriction with BglII and BstEII. The circulation of prototype-like strains of Ad 1 throughout the study period is note-worthy. Thirty-six of 43 strains corresponded to genome type D 1. Clearly, one genome type of each serotype predominated over the 7-year period (Ad 1 D 1, n = 36; Ad 2 D 5, n = 32, Ad 5 D 36, n = 17). Some genomic variants were detected sporadically and only in Argentina, Chile, or Uruguay whereas others were widely distributed and circulated for years. A high proportion of the analysed strains was isolated from children under one year and males were more frequently infected than females.

Adenoviruses, Human↗

PubMed1993

Relation between the presence of human papillomavirus type 16 deoxyribonucleic acid in cervicovaginal cells and general health condition.

Cervicovaginal cell samples were analyzed for the presence of human papillomavirus type 16 deoxyribonucleic acid. All 99 women included in the study had normal Papanicolaou smear results, normal findings on wet smear, and no clinical signs of genital papillomavirus or any other genital infection. Deoxyribonucleic acid polymerase chain reaction was performed with three different human papillomavirus type 16-specific primer pairs from the early 6, early 7, and upstream regulatory regions. Human papillomavirus type 16 was detected in 21% of the 99 women. Seven of 69 women (10%) who were not taking any medication except for cyclic estrogen or progestin replacement therapy were carriers of human papillomavirus type 16. Seven of 19 women (37%) who used hormonal contraceptives or who sought early pregnancy termination were carriers of human papillomavirus type 16. All 7 women with diseases that required frequent hospital care were carriers of human papillomavirus type 16. The 4 women who had never had sexual intercourse were not carriers of human papillomavirus type 16. Our results indicate that the human papillomavirus type 16 prevalence in women may reflect to some extent the general health conditions of the patients.

Adolescent↗

PubMed1993

Genital human papillomavirus infection among patients attending an STD clinic.

OBJECTIVES--To determine the prevalence of human papillomavirus (HPV) infection in patients, male and female, attending a clinic for sexually transmitted diseases (STDs). DESIGN--A randomly selected group of patients representative of the population studied and first-time visitors to the STD clinic, were asked to participate in the study. Samples from the skin and mucous membranes of the lower genital region were taken for cytological analysis by the polymerase chain reaction (PCR) method for HPV DNA. The patients then underwent colposcopy or peniscopy after acetic acid application. SETTING--Department of Dermatology and Venereology, University Hospital, Uppsala, Sweden. SUBJECTS--A total of 131 patients, 66 women and 65 men, attending the clinic for various reasons. RESULTS--At colposcopy/peniscopy, 18 patients (10 men and 8 women) had lesions typical of, and 24 (12 men and 12 women) suspicious of HPV infection. With the PCR technique HPV DNA was detected in 72% of the patients with typical lesions and in 54% of those with suspicious lesions. CONCLUSION--Nearly one-third or 30.5% of these randomly selected patients in a Swedish STD clinic were infected by HPV. The diagnosis was made by clinical inspection and/or by HPV DNA analysis with PCR.

Adolescent↗

PubMed1992

Molecular epidemiology of adenoviruses associated with acute lower respiratory disease of children in Buenos Aires, Argentina (1984-1988).

DNA restriction analysis was carried out on a sample of 73 adenovirus strains isolated in Buenos Aires from nasopharyngeal aspirates of children with lower acute respiratory infection between 1984 and 1988. Thirty-five isolates (47.9%) were classified as members of subgenus B. Of these, three were identified as a new genome type of Ad3p denominated Ad3p3; five strains corresponded to genome type 7b and two to genome type 7c. The other 25 isolates were identified as the recently recognized genome type 7h. All 6 fatalities recorded within this group of 73 children were associated with infection by Adenovirus genome type 7h. Thirty-seven isolates (50.7%) were classified within subgenus C that corresponded to 9 different genome types denominated 1p (n = 5); 1# (n = 2); 2p (n = 4); 2b (n = 6); 2# (n = 5); 5# (n = 4); 5* (n = 7) and 5+ (n = 2). All genome types of subgenus C were compared with the data reported by Adrian et al. (Archives of Virology 112:235-238, 1990). The Ad1p and Ad1# genome types could be allocated to AV1 genome types D1 and D10, respectively. Ad2b genome type could be allocated to AV2 genome type D25. No counterparts were found for the remaining 6 genomic variants. Only one isolate was identified as Ad4a of subgenus E. The comparison of the results of the present study with those of the molecular characterization of Chilean strains isolated between 1984 and 1987 suggests that the adenovirus strains associated with respiratory disease of children may be common in both countries.

Acute Disease↗

PubMed1992

Detection of adenoviruses in stools from healthy persons and patients with diarrhea by two-step polymerase chain reaction.

The use of the polymerase chain reaction (PCR) for detection of human adenoviruses in diluted stool samples was investigated. Two sets of nested primers, including primers specific for the hexon-coding region and for the E1B region of enteric adenoviruses (EAd), were assessed by two-step amplification. The primers constitute two different PCR systems designed for the detection of adenoviruses belonging to all six subgenera (A-F), and the two EAds Ad40 and Ad41, respectively. In a two-step PCR mediated amplification a single virus particle was detected when the two sets of general hexon primers or EAd specific primers were used. Earlier results from PCR detection of adenoviruses in stool from children suffering from diarrhea gave indications that adenovirus particles are commonly shed in stools without being identified as the cause of illness [Allard et al.: Journal of Clinical Microbiology 28:2659-2667, 1990]. Therefore, the general and the EAd specific PCR assays were assessed on 150 stool specimens from three groups including 50 healthy children, 50 healthy adults, and 50 adults suffering from diarrhea. When the two sets of general hexon primers were used, 25 of the 50 specimens from the healthy children (mean age 21 months) were found positive by two-step PCR amplification. Nine of the 50 specimens from the healthy adults (mean age 32 years) were found positive whereas 12 of the 50 specimens from sick adults (mean age 31 years) gave amplification products, using the two sets of general hexon primers in a nested fashion. None of the 150 specimens were found to be positive by two-step PCR amplification using the two sets of EAd-specific primers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenovirus Infections, Human↗

PubMed1992

High-risk human papillomavirus types in cytologically normal cervical scrapes from Kenya.

Seventy-seven women with normal cervical cytology on routine visit to a family planning clinic in Nairobi, Kenya, were analysed for genital human papillomavirus (HPV) types by polymerase chain reaction (PCR). We applied a general primer pair (GP60/GP124) recognising sequences conserved among HPV types 6, 11, 16, 18, 31 and 33. Of the 77 specimens tested 15 (19.5%) proved to be positive for genital HPV. Amplification products were examined for the presence of high-risk HPV types by Slot-blot hybridization. Out of the 15 PCR-positive samples, 4 were positive for HPV 16.3 for HPV 18, while 1 contained both HPV 16 and 33. HPV DNA prevalence in this group of women from a "high-risk" area is similar to that in "low-risk" Swedish women but much lower than in cervical cancer samples from the same region.

Adult↗

PubMed1992

The nucleotide sequence of adenovirus type 11 early 3 region: comparison of genome type Ad11p and Ad11a.

The early 3 region (E3) of two strains (genome type Ad11p and Ad11a) of human adenovirus serotype 11, causing persistent urinary and acute respiratory illnesses, respectively, has been identified and partially sequenced. The sequenced E3 regions of Ad11p and Ad11a were 1980 and 1966 bp long and encoded three complete ORFs, 18.5, 20.3, 20.6k within the Ad11p genome and 18.5, 20.3, 20.2k within the Ad11a genome. The sequence analysis of the 18.5k gene product demonstrated that a transmembrane domain and a cytoplasmic domain of Ad11p, Ad11a, and Ad35 was identical. Ad11p and Ad35 were homologous in the signal sequence. There was one amino acid mismatch between Ad11p and Ad11a, represented by an alanine instead of a proline. The endoplasmic reticulum lumenal domain, which binds to class I MHC, was relatively conserved between Ad11p and Ad11a with the exception of Glu80 and Glu104 in Ad11p, which were replaced by Gln80 and Lys104 in Ad11a. Within the 20.2k protein of Ad11a, the amino acid sequence Thr-Thr-Ser-His was deleted from a position immediately upstream the transmembrane region of the Ad11p 20.6k protein. The 9.0k E3 open reading frame (ORF) of Ad3 was deleted in the genomes of Ad11p and Ad11a. It is noteworthy that Ad11p and Ad35 which both cause persistent infection of the urinary tract display a remarkable similarity in several ORFs of the E3 region.

Adenovirus E3 Proteins↗

PubMed1992

The E1B transcription map of the enteric adenovirus type 41.

Enteric adenovirus type 41 (Ad41) is defective for growth in conventional established cell lines. Ad41 is dependent on the Ad5 early regions E1A/E1B since it cannot grow in HEK cells but only in 293 HEK cells transformed by Ad5 E1 region. However, Hep-2 cells have also been shown to support the growth of Ad41 to some extent. The nucleotide sequence of the E1B region of the Ad41 strain D389 has been determined. When compared to the corresponding region of the Ad41 prototype strain (Tak) the degree of homology in the DNA sequences was close to 100%. The mRNAs from the E1B region of the Ad41 strain D389 have been studied by Northern blot, primer extension, and polymerase chain reaction-cDNA analysis. E1B transcripts corresponding to Ad2 14 S, 22 S, and 9 S mRNAs were identified but no 13 S mRNA equivalent was detected, a pattern similar to that seen in the Ad40 and Ad12 transcription maps. However, the Ad41 E1B 14S mRNA equivalent has one additional small exon of 23 nucleotides, created by a donor and an acceptor splice site located at positions not seen in other E1B transcripts of human adenoviruses analyzed so far. The coding potential for E1B 19K, 55K, and 15K proteins and for pIX is retained in the Ad41 transcripts. In contrast to other adenoviruses, except for the closely related Ad40, the ORF of pIX starts in the intron of the 22 S mRNA.

Adenovirus Early Proteins↗

PubMed1992

Detection of nephropathia epidemica virus RNA in patient samples using a nested primer-based polymerase chain reaction.

A nested primer-based polymerase chain reaction was constructed for the detection of Puumala virus RNA in patient samples. Puumala virus RNA was detected in cells from the urinary and the respiratory tracts and in peripheral blood mononuclear cells of patients with nephropathia epidemica. After inoculation with nephropathia epidemica patient material on Vero E6 cells and propagation for nine passages (4 months), Puumala virus RNA was detected at every passage. Hybridization under high-stringency conditions revealed that the overall nucleotide homology between the different patient isolates and the prototype strain (Puumala) is high. Using cDNA from Hällnäs B1 strain as a probe, hybridization occurred only under low-stringency conditions.

Animals↗

PubMed1992

Comparison of a one-step and a two-step polymerase chain reaction with degenerate general primers in a population-based study of human papillomavirus infection in young Swedish women.

The prevalence of human papillomavirus (HPV) infection in cervical cell scrapes from young women was determined by polymerase chain reaction (PCR) by using general primer pairs localized within the L1 region. With a one-step general PCR, 5.9% (35 of 590) of young women in a population-based study were found to contain HPV DNA. The proportion of HPV-positive women increased with age, from 1.4% (1 of 69) among women aged 19 years to 9.2% (13 of 142) among women aged 25 years. Among the cervical scrapes from women with normal cytology, 5.6% (30 of 539) harbored HPV DNA. A total of 5 of 19 (26.3%) of the women with pathological signs were positive for HPV DNA. By a two-step PCR, using nested general primers, 20.3% (118 of 581) of all women were shown to contain HPV DNA. The proportion of HPV-positive women also increased with age, from 17.4% (12 of 69) among women aged 19 years to 31.9% (43 of 135) among women aged 25 years, when the two-step PCR was used. Some 19.2% (102 of 530) of cervical scrapes from women with normal cytology contained HPV DNA. Among the women with pathological signs, 16 of 19 (84.2%) were positive for HPV DNA. The HPV DNA-positive specimens were demonstrated to contain HPV type 6, 11, 16, 18, 31, 33, 35, 39, 40, 45, 55, or 56. The most prevalent HPV types were 6 (2.0%) and 16 (2.7%). More than one type was found in 16 specimens. Sixty HPV-positive samples could not be typed.

Adult↗

PubMed1992

Characterization of adenovirus genome type 7h: analysis of its relationship to other members of serotype 7.

Ad7h is a newly identified genome type associated with severe lower acute respiratory infections and has so far been isolated only in South America. To obtain a clue to its possible origin, the degree of restriction enzyme site homology between adenovirus genome type 7h and those representative of the three described genomic clusters (GC) for serotype 7 was studied by analysis of pairwise comigrating DNA restriction fragments (PCRF) after digestion with BamHI, BglI, BglII, BstEII, EcoRI, HindIII, HpaI, SalI, SmaI, XbaI, and XhoI. The most closely related genome types, Ad7b, Ad7d, and Ad7g, displayed 85.7, 83.8, and 82.8% comigrating fragments, respectively. Ad7p (GC1) was clearly distant with only 68.6% PCRF. No remarkable close genetic relationships (%PCRF greater than 90) were observed with any of the genome types grouped within GC3 or with Ad7g (the only member of GC2), so since Ad7h seems to be related to both members of GC2 and GC3, it could equally be considered to represent a new cluster or to end up grouped in either GC2 or GC3, depending on the results of further analysis.

Adenoviridae↗