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G Wadell

Publications and source records attributed to G Wadell.

At least 109 records · Page 6Linked to original sources
PubMed1988

The degree of genetic variability among adenovirus type 4 strains isolated from man and chimpanzee.

A total of 8 different genome types of adenovirus type 4 (Ad 4), Ad 4p, Ad 4p 1-3, Ad 4a, Ad 4a 1, Ad 4b, and Ad 4ch were identified among 50 selected human adenovirus isolates and 2 chimpanzee adenovirus strains using 16 restriction endonucleases Bam HI, Bcl I, Bgl I, Bgl II, Bst EII, Dra I, Eco RI, Eco RV, Hind III, Hpa I, Sal I, Sma I, Ssp I, Pst I, Xba I, and Xho I. They could be divided into three genomic clusters. Cluster 1 contained Ad 4p and Ad 4p 1-3; cluster 2 contained Ad 4a, ad 4a 1 and Ad 4b; whereas the chimpanzee Ad 4 genome type was the unique member of cluster 3. The degree of genetic variability within each cluster was minor. The genome types within one cluster display 95-99% pairwise comigrating restriction fragments (PCRF). However, the genetic space between the three clusters was large. The genome types between different clusters share only 25-46% PCRF. A comparative PCRF analysis performed with restriction endonucleases Apa I, Nar I, Nae I, Sac II, and Sma I recognizing exclusively G and C sequences and Dra I, Ssp I recognizing exclusively A and T containing sequences revealed that G and C rich regions were significantly more conserved than A and T rich regions.

Adenoviridae↗
PubMed1988

Physical organization of the enteric adenovirus type 41 early region 1A.

Enteric adenovirus types 40 and 41 (Ad40 and Ad41), representing subgenus F, differ from all other human adenoviruses by being so fastidious that productive replication does not occur in conventional established cell lines. They are dependent of the Ad5 early regions E1A and E1B since they can not grow in HEK cells, only in 293 HEK cells transformed by Ad5 E1. The overall genetic organization of Ad41 E1A is similar to the E1A region of other characterized human adenoviruses but it is slightly shorter, comprising 1350 bp. The inverted terminal repeat (ITR) at the 5' end of both Ad40 and AD41 consists of 163 nucleotides, being similar to the ITR of Ad12 (subgenus A) and longer than the ITRs of adenoviruses of subgenera B, C, and E. The early mRNA products (12 and 13 S) can be translated into a 222-amino acid (aa) and a 251-aa tentative protein, respectively. In a comparison of the Ad41 251-aa protein with corresponding peptides of Ad12, Ad7, Ad5, and Ad4, three conserved amino acid sequences CS1-CS3 can be found. In the second conserved domain CS2, which is particularly acidic, the homology is very high within all five serotypes compared. Only one among eight conserved amino acids differs in the Ad41 251-aa protein. Within CS1 and CS3 which exhibit a hydrophilic and a hydrophobic character, respectively, the amino acid composition of the Ad41 protein is less conserved than the corresponding regions in all other analyzed adenovirus types. Ten of 16 conserved amino acids in CS1 are shared by Ad41 and 18 of 23 conserved amino acids in CS3 are shared by Ad41.

Adenoviridae Infections↗
PubMed1988

Incidence and geographic distribution of serologically verified cases of nephropathia epidemica in Sweden.

A nationwide survey of hospitalized, serologically verified adult nephropathia epidemica cases in Sweden from 1978 to 1981 was performed. Serum was collected from 1,063 patients with a diagnosis of nephropathia epidemica or one of 10 other renal diseases with related symptoms. Sera were analyzed by indirect immunofluorescence technique for the presence of immunoglobulin G antibodies to Hantaan virus, causative agent of Korean hemorrhagic fever that cross-reacts with the nephropathia epidemica agent. Antibodies were present in 368 patients, 355 of whom also fulfilled four or more of six criteria for clinical diagnosis of nephropathia epidemica. The male:female ratio was 2.7:1. The total number of cases in Sweden varied between 26 and 144 per year, which coincided with the fluctuations in small rodent populations. The highest incidence was found in Västerbotten County, with a maximum crude incidence rate of 23.5 cases per 100,000 inhabitants per year. Mean crude incidence in Sweden during the study period was 1.3 cases per 100,000 inhabitants per year. The southernmost cases lived in proximity to the 59th parallel. Thus, nephropathia epidemica was found to be prevalent south of the 60th parallel, which was previously assumed to be its southern boundary.

Adolescent↗
PubMed1988

Comparison of 17 genome types of adenovirus type 3 identified among strains recovered from six continents.

Restriction endonucleases BamHI, BclI, BglI, BglII, BstEII, EcoRI, HindIII, HpaI, SalI, SmalI, XbalI, and XholI were used to analyze 61 selected strains of adenovirus type 3 (Ad3) isolated from Africa, Asia, Australia, Europe, North America, and South America. It was noted that the use of BamHI, BclI, BglII, HpaI, SalI, and SmaI was sufficient to distinguish 17 genome types; 13 of them were newly identified. All 17 Ad3 genome types could be divided into three genomic clusters. Genome types of Ad3 cluster 1 occurred in Africa, Europe, South America, and North America. Genomic cluster 2 was identified in Africa; genomic cluster 3 was identified in Africa, Asia, Australia, Europe (a few), and North America. This was of interest because 15 identified genome types of Ad7 could also be divided into three genomic clusters. The degree of genetic relatedness between the 17 Ad3 and the 15 Ad7 genome types was analyzed and was expressed in a three-dimensional model.

Adenoviruses, Human↗
PubMed1988

DNA restriction enzyme analysis of bovine adenoviruses.

Eight reference strains of the nine accepted bovine adenovirus serotypes were compared by means of restriction enzyme (RE) analysis of the viral DNA. The study was carried out with the aim to identify RE giving restriction patterns which are particularly feasible for identification of new isolates and useful for their classification into subgroups. The BamHI, EcoRI, HindIII and PstI enzymes were feasible for identification of strains. The classification of bovine adenovirus (BAV) into subgroup 1 (BAV-1, 2, 3 and 9) and subgroup 2 (BAV-4, 5, 6, 7 and 8) was supported by (i) the significant difference in genome size between members of subgroup 1 (ranging from 32.73 to 37.67 kb) and members of subgroup 2 (ranging from 28.78 to 31.18 kb); and (ii) the observation that the nucleotide sequence recognized by EcoRI is less frequent in the genomes of subgroup 1 members - yielding 4-7 RE fragments - than in the genomes of subgroup 2 members - yielding 10-16 RE fragments.

Adenoviridae↗
PubMed1987

Enteric adenoviruses.

The 41 serotypes of human adenoviruses are classified into six subgenera (A-F) with different tropisms. Enteric infections are caused in children by serotypes Ad40 and Ad41 of subgenus F. Serotypes Ad40 and Ad41 transform embryonic cells but cannot induce tumours in newborn hamsters. They differ from all other (established) human adenoviruses by being unable to replicate in conventional cell cultures. Ad40 and Ad41 grow in 293 cells (human embryonic kidney cells immortalized by transfection with the E1A, E1B regions of Ad5). In spite of the difficulty of isolating Ad40 and Ad41 they can be directly identified in stools by enzyme-linked immunosorbent assay (ELISA) and solid-phase immuno-electron microscopy. The amount of viral DNA in stool preparations is sufficient for identification by DNA restriction or dot-blot analysis. Adenoviruses have been associated with 7-17% of cases of diarrhoea in children. Ad40 and Ad41 cause diarrhoea throughout the year. Clinical features are watery stools, vomiting and moderately elevated temperature; respiratory symptoms are infrequent. The diarrhoea is protracted (mean 8.6 and 12.2 days for Ad40 and Ad41 respectively). Children with rotavirus diarrhoea vomited more frequently and had a higher temperature and diarrhoea of shorter duration. The impact of enteric adenoviruses in the aetiology of diarrhoea world-wide is not known but is accessible to investigation.

Adenoviridae Infections↗
PubMed1987

Serological and biochemical characteristics of intermediate adenovirus strains of subgenus D.

Ten serologically intermediate strains of subgenus D related to six different serotypes were characterized by neutralization and hemagglutination-inhibition and by DNA restriction analysis with the endonucleases BamHI, BglII, BstEII, HindIII, and SmaI. Each strain was a unique genome type. While the serologically identical strains showed only slight variations in their DNA, the comparison of the intermediate strains with the serologically related prototypes resulted in only moderate DNA relationship (53 to 73% comigrating fragments, with one exception). Hence the possibility that the intermediate strains have originated by recombination of two prototype-like strains is unlikely. One strain lost its cross-reactivity with AV19 in hemagglutination-inhibition after terminal dilution.

Adenoviruses, Human↗
PubMed1987

Serum antibody responses to individual viral polypeptides in human rotavirus infections.

A radioimmunoprecipitation assay (RIPA) was used to study the serum antibody responses to individual polypeptides that developed after infection with viruses from human rotavirus subgroups I and II. Paired sera from eight children (1 to 8.5 years of age) were used in the study. Although all of the eight acute sera were negative by the complement fixation test, four of them were positive by RIPA, indicating a previous infection by rotavirus. A significant difference in the number of polypeptides immunoprecipitated was seen among the convalescent sera. The number of polypeptides immunoprecipitated was found to be related to previous infection experience. At most, ten different polypeptides were immunoprecipitated: seven structural polypeptides VP1 to VP7 and three non-structural polypeptides, NS1, NS2 and NS3. No sera immunoprecipitated VP8 or VP9. Acute sera positive by RIPA immunoprecipitated up to five polypeptides, VP1, VP2, VP3, VP4 and VP6. One of the non-structural proteins (NS2) was found to be particularly immunogenic, since antibodies to this polypeptide were detected in several convalescent sera. Among the structural proteins VP2 and VP6 were found to be the two immunodominant polypeptides which were recognized by all convalescent sera. Only three convalescent sera immunoprecipitated VP7, the major type-specific antigen responsible for inducing neutralizing antibodies. Three of four originally seronegative children with no reactivity in the convalescent sera to VP7 developed neutralizing antibodies to a single serotype. One child developed antibodies to two serotypes.

Antibodies, Viral↗
PubMed1987

Genomic comparison of herpes simplex virus type 1 isolates from Japan, Sweden and Kenya.

One-hundred and seventy-two epidemiologically unrelated herpes simplex virus type 1 (HSV-1) strains isolated in Japan (104 strains) and Sweden (68 strains) were compared by analysis of their genome structures using four restriction endonucleases, BamHI, KpnI, SalI and HindIII. In addition, 32 Kenyan HSV-1 isolates previously compared to Japanese isolates were included for further comparison with the Swedish isolates. Remarkable and statistically significant differences were found between the HSV-1 isolates from the three countries. One-hundred and thirty cleavage sites were examined, and it was shown that isolates from two of the three countries were statistically distinguishable at 27 of these loci. Pairwise comparison between isolates from Japan and Sweden, Kenya and Sweden, and Japan and Kenya revealed variation in 18, 16 and 23 sites, respectively. By considering gains and losses of 19 sites, the total of 204 strains could be classified into 92 distinct cleavage patterns. Isolates from the three countries could be distinguished from each other by the pattern, except for one Swedish and two Kenyan isolates which shared a pattern. Twenty-one fragments that were present or absent only in individual isolates from one or other of the three countries could be detected. These results show that HSV-1 strains from geographically separate countries or anthropologically different races have distinct distributions of endonuclease recognition sites.

DNA Restriction Enzymes↗
PubMed1987

Immune response to rotavirus polypeptides after vaccination with heterologous rotavirus vaccines (RIT 4237, RRV-1).

The antibody response to individual rotavirus polypeptides after vaccination with live attenuated heterologous rotavirus vaccines was studied with a radioimmunoprecipitation assay (RIPA). Following vaccination with bovine rotavirus strain RIT 4237 and rhesus monkey rotavirus strain RRV-1, an antibody response was demonstrated mainly against the inner capsid polypeptides VP2 and VP6 and to a lesser extent against VP3/VP4. There was no qualitative difference between the vaccines in the antibody response; both vaccines induced antibodies against the same polypeptides. Quantitatively the antibody response to RRV-1 was somewhat stronger. All prevaccination sera contained by RIPA low levels of rotavirus antibodies. The effect of these antibodies on the 'take' of the vaccines is discussed.

Antibodies, Viral↗
PubMed1987

Detection of specific serum immunoglobulin M in nephropathia epidemica (Scandinavian epidemic nephropathy) by a biotin-avidin-amplified immunofluorescence method.

A biotin-avidin-amplified indirect immunofluorescence method was used to demonstrate specific serum immunoglobulin M (IgM) antibodies in nephropathia epidemica, the Scandinavian type of hemorrhagic fever with renal syndrome. The antigen in the test was the cross-reacting agent of Korean hemorrhagic fever, Hantaan virus. Sixty-two serum samples from 15 patients with clinically typical nephropathia epidemica were analyzed. Eleven patients had specific IgM in one or more serum samples. The IgM could be demonstrated from day 2 up to day 37, and all patients had detectable specific IgM within 15 days after the onset of disease. In 49 control serum samples, no specific IgM could be detected, indicating a high specificity for the method. The findings demonstrate that the biotin-avidin-amplified immunofluorescence IgM assay is a useful tool in the diagnosis of early nephropathia epidemica disease.

Adult↗
PubMed1986

Molecular epidemiology of rotavirus infections in Uppsala, Sweden, 1981: disappearance of a predominant electropherotype.

The molecular epidemiology of rotavirus infections was studied in children with acute gastroenteritis in Uppsala, Sweden, during 1981. Altogether 118 virus strains were investigated by analysis of the RNA migration pattern in silver-stained polyacrylamide gels. Six different electropherotypes were seen: two with "short" and four with "long" RNA migration patterns. Forty-two strains (36%) exhibited "short" patterns. The seasonal distribution showed that strains with "long" and "short" RNA patterns cocirculated in equal frequency during the first seven months of the year, until the predominant "short" RNA electropherotype suddenly disappeared. More than 11 RNA segments were seen in two stool specimens. A complete correlation was found between the electrophoretic migration of segments 10 and 11 and the serological defined subgroup specificity.

Adolescent↗
PubMed1986

DNA restriction analysis of adenovirus prototypes 1 to 41.

DNA restriction patterns of all known human adenovirus prototypes (1 to 41), ordered according to subgenera A to F, are presented for restriction endonucleases BamHI, BglII, BstEII, HindIII, and SmaI. This catalogue is a prerequisite for typing of adenoviruses by DNA restriction analysis in diagnostic laboratories and for strain identification in reference laboratories. To determine the genetic relationship of human adenoviruses within a subgenus and between subgenera, a pairwise analysis of comigrating fragments was performed. Adenoviruses of subgenus C were closely related. Adenoviruses of subgenus B showed two related clusters of four types each, whereas the numerous serotypes of subgenus D did not show any corresponding clustering. Little comigration was observed between DNA restriction fragments from members of subgenus A or F respectively.

Adenoviruses, Human↗
PubMed1986

Aetiology and epidemiology of acute gastro-enteritis in Swedish children.

In a prospective 1-year study, 144 children attending or admitted to hospital and 272 children outside hospital with acute gastro-enteritis and 200 controls were investigated by a broad panel of diagnostic methods for enteropathogenic agents in the faeces and for related antibody responses. Enteropathogens were identified in 77% of the inpatients, 63% of the outpatients and 8% of the controls. Rotavirus and Yersinia enterocolitica were detected significantly more often among inpatients. Altogether, viral, bacterial and parasitic agents were found in 58%, 14% and 1% of diarrhoeal patients, respectively. The isolation of more than one pathogenic agent was uncommon (6.5%). Rotavirus (45%) and enteric adenoviruses 40 and 41 (7.9%) predominated among the viruses, while Campylobacter jejuni (4.8%) was most common among the bacteria. Clostridium difficile and/or its cytotoxin, which were found in 14% of the children with gastroenteritis and in 15% of the controls, were significantly associated with antibiotic therapy but not with gastro-intestinal illness. Diarrhoeal infections of unknown aetiology exhibited a seasonal peak in the autumn. The duration of excretion of enteropathogens was investigated. Rotavirus particles were detectable by solid-phase immune electron microscopy for 14-25 days after the diarrhoea had ceased. Transmission of rotavirus and bacterial pathogens within families was studied also.

Acute Disease↗
PubMed1986

Analysis of 15 different genome types of adenovirus type 7 isolated on five continents.

A total of 15 different genome types of adenovirus type 7 (Ad7), i.e., Ad7p, Ad7p1, Ad7a, Ad7a1 to Ad7a5, Ad7b, Ad7c, Ad7d, Ad7d1, Ad7e, Ad7f, and Ad7g, were identified among 40 selected strains isolated in Europe, Asia, North America, South America, and Australia by using restriction endonucleases BamHI, BclI, BglI, BglII, BstEII, EcoRI, HindIII, HpaI, SalI, SmaI, XbaI, and XhoI. Eight of them, Ad7p1, Ad7a1 to Ad7a5, Ad7d1, and Ad7g, are newly discovered. All 15 genome types could be distinguished by the four restriction endonucleases BamHI, BclI, BglI, and XbaI. At least four restriction sites differed between Ad7d and Ad7g. Pairwise analyses of comigrating DNA restriction fragments of all 15 Ad7 genome types were performed and presented in a schematic fashion. According to the degree of comigration of DNA restriction fragments, the 15 genome types could be divided into three clusters. Ad7b was the dominant genome type in different parts of the world and may have evolved in China into Ad7d and further to Ad7d1.

Adenoviridae Infections↗