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Biomedical subjects

Anders Johansson

Publications and source records attributed to Anders Johansson.

At least 37 records · Page 2Linked to original sources

Evolution of subspecies of Francisella tularensis.

Analysis of unidirectional genomic deletion events and single nucleotide variations suggested that the four subspecies of Francisella tularensis have evolved by vertical descent. The analysis indicated an evolutionary scenario where the highly virulent F. tularensis subsp. tularensis (type A) appeared before the less virulent F. tularensis subsp. holarctica (type B). Compared to their virulent progenitors, attenuated strains of F. tularensis exhibited specific unidirectional gene losses.

Evolution, Molecular↗

Tularemia in Denmark: identification of a Francisella tularensis subsp. holarctica strain by real-time PCR and high-resolution typing by multiple-locus variable-number tandem repeat analysis.

We report ulceroglandular tularemia affecting an 8-year-old boy and the first recovery of Francisella tularensis in Denmark. A novel real-time PCR assay was used to identify the strain as F. tularensis subsp. holarctica (type B). Multiple-locus variable-number tandem repeat analysis demonstrated a close genetic relationship to strains from Norway.

Bacterial Typing Techniques↗

Anticancer effects of a plant lignan 7-hydroxymatairesinol on a prostate cancer model in vivo.

Clinical intervention studies and experimental studies with lignan-rich diets suggest that lignans may have inhibitory effects on prostate cancer, but no clinical or experimental studies with purified lignans have been published. The purpose of this study was to investigate the effect of a plant lignan 7-hydroxymatairesinol (HMR) on LNCaP human prostate cancer xenografts in athymic mice. Athymic nude male mice were injected subcutaneously with LNCaP cells. Starting 3 days after tumor cell injections, a control diet or a control diet supplemented with 0.15% or 0.30% of HMR was administered to mice and the tumor take rate and growth was observed for 9 weeks. HMR diet inhibited the growth of LNCaP tumors. Mice treated with HMR had smaller tumor volume, lower tumor take rate, increased proportion of nongrowing tumors, and higher tumor cell apoptotic index compared with controls. Furthermore, the cell proliferation index was reduced in mice receiving the 0.30% HMR diet compared with mice receiving the control diet. Our results suggest that dietary HMR started at the early phase of the tumor development inhibits the growth of the LNCaP human prostate cancer xenografts in athymic male mice.

Animals↗

Increased interleukin-18 in patients with juvenile idiopathic arthritis and early attachment loss.

BACKGROUND: Patients with juvenile idiopathic arthritis (JIA) have been shown to have incipient attachment loss (AL) more frequently than systemically healthy individuals. This study investigated neutrophil activity and proinflammatory cytokines in these patients and aged-matched controls. METHODS: Elastase activity, measured with a low molecular weight substrate (S-2484), and interleukin-1beta (IL-1beta), measured with the enzyme-linked immunosorbent assay (ELISA), were analyzed in the gingival fluid of 38 patients with JIA and 29 controls. IL-1beta and interleukin-18 (IL-18) were measured with ELISA in the serum of the same groups. Subgingival plaque was analyzed by DNA probes to detect 12 bacteria. RESULTS: Significantly elevated serum levels of IL-1beta and IL-18 were found in the JIA group. No differences were found in the gingival fluid levels of elastase and IL-1beta between groups, or in the frequency of subjects positive to most of the bacteria analyzed, except F. nucleatum, C. rectus, P. micros, and S. intermedius, which were significantly more frequent in the control group. When the JIA group was subdivided according to the presence/absence of AL, IL-18 was significantly increased in the JIA subgroup with AL compared to those without it. There were no differences in the subgingival microbiota between the subgroups. CONCLUSION: The findings of increased serum IL-18 and IL-1beta in patients with JIA accompanied by a similar subgingival microbiota suggest that the increased frequency of incipient attachment loss observed in these patients might be due to their altered systemic inflammatory response, making them more susceptible to periodontal disease.

Adolescent↗

Silicone sealers, acetic acid vapours and dental erosion: a work-related risk?

The aim of the present study was to investigate whether the acetic acid released by some silicone sealers during the curing process poses an increased risk for dental erosion, thus constituting an occupational hazard to exposed individuals. The material comprised 13 individuals (x=30 years, 10 men and 3 women) who had been exposed to an average of 4.2 years' (range 0.6-10 years) of working with silicone. Each had comprehensive medical and dental examinations carried out. A sex- and aged-matched group of 20 healthy, unexposed workers from the same company served as controls for the medical examination, while study models from randomly selected sex- and age-matched individuals were used as controls for assessing the severity of erosion. Using a questionnaire, an assessment of the role of various possible factors related to oral and general health, and to dental erosion in particular, was made for each participant in the exposed group. Clinical examination included recordings of severity of dental erosion, presence of "cuppings", DMFT, salivary secretion rate and buffer capacity, visible plaque index and gingival bleeding index. In addition, bitewing radiographs, study casts and intraoral colour transparencies were obtained for each individual. The severity of dental erosion was significantly higher in those exposed to silicone compared to controls. There was also a significant correlation between the period of exposure to silicone in the workplace and severity of erosion. Medical problems, especially with regard to upper respiratory tract symptoms, were significantly more common among exposed individuals than controls. In conclusion, a relationship between occupational exposure to acetic acid vapours from silicone sealers and development of dental erosion would appear to exist.

Acetic Acid↗

[Microbial diagnosis with PCR will become clinically beneficial with a faster analysis].

PCR was introduced in 1985 by Mullis and was immediately recognized as a valuable tool in biomedical research and was awarded the Nobel Prize in 1993. Two culture-negative meningitis cases are described where Haemophilus influenzae and Neisseria meningitidis were found by 16SRNA-PCR. The modern real time PCR technology using fluorescent probes (hybridization probes, lightup probes, molecular beacons etc) for detection of the PCR-product or on DNA microarray chips, is under development for routine use. Multiplex technology can be used to simultaneously detect multiple microorganisms as well as resistance genes. Using super-convection with ultracentrifugation high-speed PCR, results can be obtained in 10 minutes and the amplificate can also be analyzed by DNA-sequencing to achieve species identification as well as detection of resistance gene mutations. The technique has mainly been applied to viruses, but is now slowly adapted to bacteria, fungi, protozoa and helminths. PCR is especially well suited for slow growing bacteria like Mycobacteria, fastidious organisms like Bartonella and contagious agents like tularemia, but also for malaria and fungi, where the advantages in sensitivity and speed can be exploited. The limit for application to routine analysis will depend on the development of simple and fast procedures for nucleic acid extraction, as well as interpretation of the PCR analysis per se, since highly efficient thermocyclers now are on the markets.

Adult↗

Cerebrospinal fluid protein patterns in neurodegenerative disease revealed by liquid chromatography-Fourier transform ion cyclotron resonance mass spectrometry.

This study demonstrates the power of a novel proteomic approach developed for the detection and identification of biological markers in body fluids. The goal was to observe alterations in the protein patterns of cerebrospinal fluid (CSF) related to amyotrophic lateral sclerosis (ALS), a neurodegenerative disorder with unknown etiology. In the experiments, tryptic digests of CSF from patients and healthy controls were analyzed by on-line capillary liquid chromatography-Fourier transform ion cyclotron resonance mass spectrometry. (FT-ICR MS) Typically, around 4000 peptides were detected in one such experiment, and a pattern recognition program was constructed for the data analysis to distinguish mass chromatograms from patients and controls. This strategy was evaluated comparing the peptide patterns of CSF spiked in vitro with a biomarker, with control CSF. The patterns were clearly separated and the tryptic peptides of the biomarker were successfully selected as characteristic peaks. Hence, the method was applied to compare mass chromatograms of CSF from 12 ALS-patients and 10 matched healthy controls. While no biomarker alone could be identified from the characteristic peaks, we were able to assign 4 out of 5 unknown samples correctly (i.e., 80% correctly diagnosed, 20% false-negative), and it would be 100% if we reject a possible outlier believed to be caused by an occlusion in the spinal CSF compartment. These findings are very promising, although the clinical relevance is not fully established due to the low number of unknown samples analyzed. In addition to the diagnostic potential, these results may be important steps towards understanding the neurodegenerative process.

Adult↗

Influence on the masticatory system in treatment of obstructive sleep apnea and snoring with a mandibular protruding device: a 2-year follow-up.

The aim was to identify the incidence and types of possible adverse events in the masticatory system after treatment with a mandibular protruding device (MPD) during a 2-year period in patients with obstructive sleep apnea (OSA) or snoring. The subjects comprised 65 middle-aged patients (44 OSA patients, 21 snorers). A clinical examination and a questionnaire concerning signs and symptoms from the masticatory system were performed before, after 6 months, and after 2 years of MPD use. The frequencies of registered signs from the masticatory system, such as muscle and joint tenderness, palpation, and pain during mandibular movement, decreased significantly between baseline and the 2-year follow-up. There were significant changes in the mandibular range of protrusion (+0.7 mm, P < .001), overjet (-0.5 mm, P < .001), and overbite (-0.6 mm, P < .001) compared with the initial examination. Nine patients developed a lateral open bite during treatment, and 2 of them experienced subjective symptoms related to the altered occlusion but still used the MPD every night. No patient reported pain on opening the mouth wide or during jaw movements. Two reported tiredness on jaw function. The reported frequency of headaches was also significantly reduced (P < .01). The high compliance rate in MPD use showed that the therapy is well tolerated, but there is a risk of minor alterations in the occlusion during MPD treatment.

Adult↗

Associations between social and general health factors and symptoms related to temporomandibular disorders and bruxism in a population of 50-year-old subjects.

The aim of this epidemiological study was to examine associations between temporomandibular (TMD)-related problems and variables from three domains: (1) socio-economic attributes, (2) general health and health-related lifestyle, and (3) dental attitudes and behaviors. The overall response rate to a questionnaire mailed to the total population of 50-year-old subjects in two Swedish counties (8,888 individuals) was 71%. Among the 53 questions in the questionnaire, those related to social, general health, and health-related factors were used as independent variables in logistic regression models. Three TMD-related symptoms and reported bruxism were used as dependent variables. Impaired general health was the strongest risk factor for reported TMD symptoms. Along with female gender and dissatisfaction with dental care, impaired general health was significantly associated with all three TMD symptoms. A few more factors were associated with pain from the TMJ only. In comparison, reported bruxism showed more significant associations with the independent variables. In addition to the variables associated with TMD symptoms, being single, college/university education, and daily tobacco use were also significantly correlated with bruxism. Besides female gender, impaired general health, dissatisfaction with dental care, and a few social and health-related factors demonstrated significant associations with TMD symptoms and reported bruxism.

Attitude to Health↗

Resting and stimulated whole salivary flow rates in Sjögren's syndrome patients over time: a diagnostic aid for subsidized dental care?

The aim of the present study was to evaluate Swedish and Norwegian criteria currently applied in the assessment of eligibility for subsidized dental care of Sjogren's syndrome (SS) patients. These criteria are partly based on a single salivary test showing a resting whole salivary secretion rate of < or =0.1 mL/min. Thirty secondary Sjogren (SSS) patients (29 F and 1 M) participated for the duration of the study, in which resting (RWS) and stimulated (SWS) whole salivary flow rates were collected in the morning and afternoon, over 3 consecutive weeks, once per week, as well as at different times over a 5-year period. Twenty patients presented levels of RWS flow rates of < or =0.1 mL/min on one or more occasions over a 3-week period, while 8 of these also exceeded, on one or more occasions, the cut-off level of 0.1 mL/min, indicating that salivary flow rates varied over time. Six patients showed consistently low secretion rates of RWS as well as of SWS, estimated as < or =0.1 mL/min and <0.7 mL/min, respectively. Based on the results, salivary tests that are to be used as a diagnostic aid for SS diagnosis, and thus as a basis for inclusion within the subsidy net for dental care, must be taken on several occasions in order to more accurately give information about salivary gland function. In line with this, current regulations governing the eligibility of SS patients within subsidized dental care programs should be reviewed.

Adult↗

A prospective epidemiological survey of candidaemia in Sweden.

A prospective epidemiological survey of candidaemia was performed in central Sweden from January 1998 to December 1999. In total, 191 episodes were reported with an overall rate of 0.32/1000 admissions. Candida albicans was identified in 128 cases (67%), followed by Candida glabrata in 30 (15.7%) and Candida parapsilosis in 14 (7.3%). Predisposing factors included surgery (31.4%), intensive care (18.8%), solid tumour or haematological malignancy (15.7%), and foetal immaturity (15.7%). Non-albicans Candida species were more prevalent among patients with haematological malignancies (56%), compared to surgical (30%) and ICU patients (19%). The crude mortality rate of candidaemia was 31%. The highest mortality rate was observed in patients with haematological malignancies (41.2%), age > 70 y (41%), surgery (38.5%) and infections with > 1 Candida species (40%) or C. glabrata (38%).

Adolescent↗

Worldwide genetic relationships among Francisella tularensis isolates determined by multiple-locus variable-number tandem repeat analysis.

The intracellular bacterium Francisella tularensis is the causative agent of tularemia and poses a serious threat as an agent of bioterrorism. We have developed a highly effective molecular subtyping system from 25 variable-number tandem repeat (VNTR) loci. In our study, multiple-locus VNTR analysis (MLVA) was used to analyze genetic relationships and potential population structure within a global collection of 192 F. tularensis isolates, including representatives from each of the four subspecies. The VNTR loci displayed between 2 and 31 alleles with Nei's diversity values between 0.05 and 0.95. Neighbor-joining cluster analysis of VNTR data revealed 120 genotypes among the 192 F. tularensis isolates, including accurate subspecies identification. F. tularensis subsp. tularensis (type A) isolates showed great diversity at VNTR loci, while F. tularensis subsp. holarctica (type B) isolates showed much lower levels despite a much broader geographical prevalence. The resolution of two distinct clades within F. tularensis subsp. tularensis (designated A.I and A.II) revealed a previously unrecognized genetic division within this highly virulent subspecies. F. tularensis subsp. holarctica appears to have recently spread globally across continents from a single origin, while F. tularensis subsp. tularensis has a long and complex evolutionary history almost exclusively in North America. The sole non-North American type A isolates (Slovakian) were closely related to the SCHU S4 strain. Significant linkage disequilibrium was detected among VNTR loci of F. tularensis consistent with a clonal population structure. Overall, this work greatly augments the study of tularemia ecology and epidemiology, while providing a framework for future forensic analysis of F. tularensis isolates.

Alleles↗

Increased serum and cerebrospinal fluid FGF-2 levels in amyotrophic lateral sclerosis.

Lack of growth factors and hypoxia are two recent hypotheses about mechanisms underlying motor neuron death in amyotrophic lateral sclerosis. With this background, serum from 15 patients with amyotrophic lateral sclerosis and 15 controls, and CSF from 15 patients and 10 controls were analysed for fibroblast growth factor 2 (FGF-2) using an immunoassay. Serum FGF-2 levels were higher in the patient group than in the control group. FGF-2 was detected in CSF in 11/15 patients, but in none of the 10 control subjects. There were no correlations between age, duration of disease or clinical rating and FGF-2 levels. The findings indicate that FGF-2 is involved in the pathophysiological chain of events in this disorder.

Adult↗

Wound infiltration with ropivacaine and fentanyl: effects on postoperative pain and PONV after breast surgery.

STUDY OBJECTIVE: To determine whether postoperative wound infiltration with local anesthetics combined with fentanyl improves analgesia following breast surgery; and to investigate awakening and postoperative nausea/vomiting. DESIGN: Prospectively randomized clinical study. SETTING: University hospital. PATIENTS: 45 ASA physical status I and II patients scheduled for breast surgery. INTERVENTIONS: Patients were prospectively randomized and assigned to one of three treatments during general anesthesia: postsurgical wound infiltration with ropivacaine 0.375%; wound infiltration with ropivacaine 0.375% combined with fentanyl 0.5 microg/kg; and intravenous (i.v.) fentanyl 0.5 microg/kg before skin incision and no wound infiltration. Time to first verbal response, pain at rest, postoperative nausea and vomiting, and ketobemidone and dixyrazine utilization were compared. MEASUREMENTS AND MAIN RESULTS: Time to first verbal response was significantly shorter in the i.v. fentanyl group compared to both infiltration groups (8.1 +/- 4.5 min vs. 15.3 +/- 4.3, and 12.0 +/- 5.0 min; p < 0.05, respectively). Postoperative pain at rest, and nausea and vomiting occurred with similar frequencies in the groups. Ketobemidone utilization in both infiltration groups, (2.4 +/- 1.8 mg and 3.1 +/- 1.8 mg, respectively) was not different compared to the i.v. fentanyl group (2.9 +/- 2.0 mg; NS). There were no differences in postoperative antiemetic requirements during the first, second and third two-hour periods postoperatively. The dixyrazine consumption was similar in the three groups, (0.9 +/- 1.5 mg, 0.8 +/- 1.3 mg, and 1.4 +/- 1.8 mg, respectively; NS). CONCLUSION: Postsurgical ropivacaine wound infiltration, with or without adding fentanyl, demonstrates no differences in postoperative pain relief and nausea/vomiting compared to a balanced general anesthetic including i.v. fentanyl.

Amides↗

Will the enigma of Francisella tularensis virulence soon be solved?

Francisella tularensis is one of the most infectious bacterial pathogens known and is the causative agent of the zoonotic disease tularemia. In spite of the importance of this pathogen little is known about its virulence mechanisms. However, it is clear that the bacterium is an intracellular pathogen, replicating mainly in macrophages, with replication in amoebae also having been reported. The genome sequence of a high virulence strain of F. tularensis is close to completion and when available, will stimulate further research into virulence mechanisms.

Acanthamoeba↗

Rye, lignans and human health.

Rye bran contains a high content not only of dietary fibre, but also of plant lignans and other bioactive compounds in the so-called dietary fibre complex. Blood concentrations of lignans such as enterolactone have been used as biomarkers of intake of lignan-rich plant food. At present,evidence from studies in human subjects does not warrant the conclusion that rye, whole grains orphyto-oestrogens protect against cancer. Some studies, however, have pointed in that direction,especially in relation to cancers of the upper digestive tract. A number of prospective epidemiological studies have clearly shown a protective effect of wholegrain cereals against myocardial infarctions. A corresponding protective effect against diabetes and ischaemic stroke(brain infarct) has also been demonstrated. It seems reasonable to assume that these protective effects are associated with one or more factors in the dietary fibre complex.

Cardiovascular Diseases↗

Cardiovascular disease and diabetes in the Northern Sweden Health and Disease Study Cohort - evaluation of risk factors and their interactions.

The purpose of this paper is, first, to describe the organization, sampling procedures, availability of samples/database, ethical considerations, and quality control program of the Northern Sweden Health and Disease Study Cohort. Secondly, some examples are given of studies on cardiovascular disease and diabetes with a focus on the biomarker programme. The cohort has been positioned as a national and international resource for scientific research.

Cardiovascular Diseases↗

Discrimination of human pathogenic subspecies of Francisella tularensis by using restriction fragment length polymorphism.

We describe the use of two insertion sequence elements (ISFtu1 and ISFtu2) in Francisella tularensis to type strains by restriction fragment length polymorphism (RFLP). The RFLP profiles of 17 epidemiologically unrelated isolates were determined and compared. Our results showed that RFLP profiles can be used to assign F. tularensis strains into five main groups corresponding to strains of F. tularensis subsp. tularensis, F. tularensis strain ATCC 6223, strains of F. tularensis subsp. holarctica, strains of F. tularensis subsp. holarctica from Japan, and F. tularensis subsp. mediaasiatica. The results confirm the genetic identities of these subspecies and also support the suggestion that strains of F. tularensis subsp. holarctica from Japan should be considered members of a separate biovar. These findings should support future studies to determine the genetic differences between strains of F. tularensis at the whole-genome level.

DNA Transposable Elements↗