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Biomedical subjects

T Johnsson

Publications and source records attributed to T Johnsson.

17 recordsLinked to original sources
PubMed1991

Variance in recovery of periodontitis-associated bacteria caused by sampling technique and laboratory processing.

The influence of sampling procedure and of laboratory processing on the recovery of Bacteroides gingivalis, Bacteroides intermedius, and Actinobacillus antinomycetemcomitans from periodontitis sites was evaluated. Thirty-three adult subjects with severe periodontitis participated in the study. In all, 462 samples from 81 sites were examined. The samples were taken using the paper point technique. The cultivations were performed by use of enriched Brucella agar for determination of total colony-forming units and Bacteroides species, and trypticase soy bean agar for determination of A. actinomycetemcomitans. The risk of getting a false negative result was 4% for B. gingivalis, 20% for B. intermedius, and 38% for A. actinomycetemcomitans. It was considerably reduced if duplicate samples were taken. The sampling procedure alone explained up to 98% of the false-negative results.

Adult↗
PubMed1991

Extent and Severity Index based on assessments of radiographic bone loss.

The purpose of the present study was to develop a partial recording system based on the principles of the Extent and Severity Index, aiming at describing the degree of radiographic alveolar bone loss on a population level. The data analyzed were derived from a subject sample comprising 531 individuals aged 25-75 yr. In these subjects alveolar bone level (ABL) was radiographically assessed at all approximal tooth surfaces. An ABL value of greater than 2 mm was required for a tooth site to be included in the computation of a full mouth bivariate Extent and Severity Index (FESI). A partial recording index (PESI-2) based on 18 ad hoc selected tooth sites depicted in one periapical and one vertical bitewing radiograph was evaluated in comparison with the FESI as well as with partial recording indices based on the 9 and 18 tooth sites which displayed the highest correlation with full mouth scores (PESI-9 and PESI-18, respectively). It was shown that all three partial recording systems generated values reasonably close to the full-mouth scores. However, the fitness of all partial indices varied with age. The potential of the partial indices to predict full-mouth scores could be further enhanced via simple regression models. Such an evaluation should, ideally, be carried out in an independent subject sample.

Adult↗
PubMed1991

Evaluation of a radiographic partial recording system assessing the extent and severity of periodontal destruction.

The purpose of the present study was to evaluate the validity and reliability of a partial radiographic bivariate index system (PESI-2). The principles of the index were applied to data from a random sample of 192 industrial employees aged 30-65 yr. Estimates of Extent and Severity of radiographic bone loss provided by the PESI-2, as well as adjusted estimates by means of simple regression models, were compared to values obtained by a full mouth radiographic examination. It was shown that the values provided by the PESI-2 were of rather high validity and reliability. The use of the adjusting models resulted in increased validity of the severity estimates and enhanced reliability of both components of the bivariate. The results verified the applicability of the PESI-2 in epidemiologic research of destructive periodontal disease.

Adult↗
PubMed1991

Reliability of hypocycloidal tomography for the evaluation of the distance from the alveolar crest to the mandibular canal.

When implants are to be inserted in the mandible posterior to the mental foramen, tomography is required to determine the exact location of the mandibular canal and assess the dimensions of the body and alveolar process. Previous studies have shown discrepancies between the true distance between the alveolar crest and the upper border of the mandibular canal and that measured from computed tomograms. This study evaluates the reliability of such measurements made from hypocycloidal tomograms. Six examiners, three radiologists and three oral surgeons, independently measured the distance from the alveolar crest to the upper border of the mandibular canal in transverse hypocycloidal tomograms of the mandible. Analysis of variance showed an average standard deviation between observers of 1.33 mm. This variation, which is the total of inter- and intra-observer variation conditional upon patient and radiograph, was mainly due to the latter which amounted to a mean of 1.04 mm. Calculation of lower confidence limits showed that these could be decreased by the use of several observers. Various confidence levels, equal to the probabilities of obtaining lower confidence limits which are below the true values, can be used to choose acceptable levels of risk in overestimating the true distance.

Alveolar Process↗
PubMed1990

Periodontal treatment needs assessed by the use of clinical and radiographic criteria.

The aim of the present study was to use a decision making model in order to assess the periodontal treatment needs of a random sample of employees in a large Swedish industrial corporation. The model used provided data on critical bone loss limits for different tooth types and ages, beyond which treatment must be initiated, in order to fulfill the goal of maintaining all teeth in a functional state throughout life. A sample comprising 192 subjects belonging to four age strata (31-35 yr, 41-45 yr, 51-55 yr, and 61-65 yr) was involved. From each subject, a full mouth series of intra-oral radiographs were available. The radiographic bone height was assessed at the mesial and distal aspect of all teeth by measuring the distance between the cementoenamel junction and the bone crest. The clinical examination included assessments of plaque, gingivitis, probing pocket depth, and probing attachment level. The results revealed that (i) only 3.1% of all approximal tooth sites exhibited radiographic bone loss exceeding the critical limit, (ii) all individuals and 70% of the approximal tooth sites were in need periodontal treatment when presence of gingival inflammation (bleeding on probing) was employed as the single criterion for therapeutic intervention, (iii) the proportion of individuals and tooth sites requiring treatment amounted to 98% and 27%. respectively, when a probing pocket depth of at least 4 mm was included as an additional criterion, and 54% and 4.1%, respectively, if a probing depth threshold of 6mm was used, while (iv) the use of bleeding on probing in combination with radiographic bone loss beyond the critical limits disclosed a need of treatment in 40% of the subjects and 2.5% of the approximal tooth sites.

Adult↗
PubMed1979

Prevalence of nine different micro-organisms in the female genital tract. A comparison between women from a venereal disease clinic and from a health control department.

In a study of the prevalence of nine different micro-organisms in the female genital tract in a Swedish population, significantly higher isolation rates occurred among women attending a venereal disease clinic than among those attending a gynaecological health control department. The prevalence of Candida albicans, however, was similar in different groups, individual susceptibility being the most important factor. Chlamydia trachomatis, Trichomonas vaginalis, and Mycoplasma hominis occurred concomitantly with Neisseria gonorrhoeae, indicating a similar epidemiology for all these agents. Younger patients seemed to have an increased susceptibility to C. trachomatis whereas older patients had an increased susceptibility to T. vaginalis.

Adolescent↗
PubMed1979

An outbreak of hepatitis A investigated by immune electron microscopy and enzyme-linked immunosorbent assay.

In a small outbreak of hepatitis A among members of a hospital staff, excretion of hepatitis A virus could be detected by immune electron microscopy (IEM) and enzyme-linked immunosorbent assay (ELISA) in 3 out of 3 cases tested. Significant increases in antibody titre could be shown in 4 out of 6 cases (IEM), and development of virus specific IgM was shown in all 6 cases (ELISA). Among these patients IgM could be detected after 3 months, while sera drawn after 10 months were negative.

Antibodies, Viral↗
PubMed1979

A prospective study on congenital and acquired cytomegalovirus infections in infants.

A preliminary report is presented on a current prospective virological and clinical study of congenital and acquired infant cytomegalovirus (CMV) infections. During a 1-year period, 7/2200 newborn Swedish infants investigated (0.3%) had a congenital CMV infection as shown by positive virus isolation. Two of them had typical symptoms, hepatosplenomegaly and petechiae in one case and splenomegaly in the other one. All of them had a normal birth weight and normal head circumference. No sequelae have been observed during an observation period of up to 9 months. Five out of 10 control infants followed-up acquired a CMV infection within a few months. 5/7 mothers of the congenitally infected infants and 3/14 mothers of the control infants were primiparas.

Cytomegalovirus Infections↗
PubMed1979

Fulminant hepatitis A.

During a small epidemic of infectious hepatitis, a fulminant infection with fatal outcome occurred in a 54-year-old woman. IgM antibody to hepatitis A virus was demonstrated in the serum and large amounts of hepatitis A virus were found in the liver. It is suggested that the pathogenesis may be different for fulminant hepatitis A and B infection.

Female↗
PubMed1978

Congenital and acquired cytomegalovirus infections. Virological and clinical studies on a Swedish infant population.

The study included two clinical materials. First, the frequency of cytomegalovirus and its clinical significance were studied among 661 Swedish children under one year of age admitted to a paediatric hospital. Before the age of one week 4/326 (1%) children excreted virus. At one month the frequency had risen to 6/52 (12%) and after this age the frequency was constant around 20--25%. Sixty per cent of infants born to immigrants were infected after one month of age. One of the four congenitally infected children had symptoms at birth followed by neurological sequelae. The majority of the infections acquired at birth or in early infancy seemed to be subclinical and without sequelae. Second, a retrospective investigation of 18 695 children born during a six-year period was performed. Two cases of virologically confirmed congenital cytomegalic inclusion disease was found. Regarding seven microcephalic patients in the retrospective study congenital CMV-infection could be excluded in four cases. In the remaining three cases the data did not permit any conclusions regarding the etiology.

Abnormalities, Multiple↗
PubMed1977

Family infections by reo-like virus. Comparison of antibody titres by complement fixation and immunoelectroosmophoresis.

The families of 31 index cases infected by reo-like virus were examined for gastroenteritis symptoms, virus excretion and serological evidence of infection. Excretion of virus was seen only among the children in the families, and it occurred together with gastroenteritis symptoms in 97.2% of all cases. Virtually all infected children had a significant rise in titre in paired sera. Among the parents 25.0% had a significant rise in titre associated with infections with gastroenteritis symptoms and 28.6% with symptomfree infections. A comparison between complement fixation and immunoelectroosmophoresis for detection of antibody showed that the tests gave similar results.

Adult↗
PubMed1976

Immunoelectroosmophoresis for detection of reo-like virus: methodology and comparison with electron microscopy.

In two separate studies, faecal samples were collected from children with acute gastroenteritis; the samples were tested both by electron microscopy and immunoelectroosmophoresis with a view to detect reo-like virus. In 94 per cent and 100 per cent of samples positive by electron microscopy in the first and second material, respectively, a precipitin line was found after electrophoresis, using a guinea pig antiserum against a purified bovine virus. No false positives were detected by this method.

Child↗
PubMed1976

Occurrence of reo-like calf viruses in young children with acute gastroenteritis. Diagnoses established by electron microscopy and complement fixation, using the reo-like virus as antigen.

In the course of a six-month-study of acute gastroenteritis in children of ages up to six years, a reo-like virus was found in 54 per cent of the faecal specimens obtained at an early stage of the disease, using electron microscopy as screening test. By means of a concentrated complement fixation antigen, composed of a related calf diarrhoea virus cultivated in tissue culture, the rise in titre was found to be significant in 96 per cent of the patients whose faeces contained the reo-like virus. Antibodies were present in the remaining 4 per cent without rise in titre. In 10 per cent of the cases with gastroenteritis infection was caused by adenovirus or Salmonella. A probable aetiological agent was found in 71 per cent of the patients. It applies to 33 per cent of all cases caused by the reo-like virus that they were nosocomial infections.

Acute Disease↗
PubMed1975

Demonstration by immunoelectro-osmophoresis of precipitating antibodies to a purified rubella virus antigen.

The nonionic detergent Triton X-100 was used to extract antigens of rubella virus from infected tissue culture cells. Three virus-specific antigens were demonstrated by crossed immunoelectrophoresis by using a pool of human gamma globulin as antiserum. The most dominant of these antigens were purified by ion-exchange chromatography on diethylaminoethyl-cellulose. This antigen was of glucoprotein nature and had slow electrophoretic motility and low binding capacity to diethylaminoethyl-cellulose. Thus, it seems likely that the antigen is identical with the precipitating antigen of rubella virus designated b-antigen or tro-osmophoresis with precipiting antibody in sera obtained from patients recovering from acute postnatal rubella. The precipitin reaction that could be correlated to the hemaglutination-inhibition titers of the same sera appeared 12 days after onset of the disease and remained positive for several years.

Animals↗