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Biomedical subjects

J Peltola

Publications and source records attributed to J Peltola.

At least 37 records · Page 2Linked to original sources
PubMed2001

Toxic-metabolite-producing bacteria and fungus in an indoor environment.

Toxic-metabolite-emitting microbes were isolated from the indoor environment of a building where the occupant was suffering serious building-related ill-health symptoms. Toxic substances soluble in methanol and inhibitory to spermatozoa at <10 microg (dry weight) ml(-1) were found from six bacterial isolates and one fungus. The substances from isolates of Bacillus simplex and from isolates belonging to the actinobacterial genera Streptomyces and Nocardiopsis were mitochondriotoxic. These substances dissipated the mitochondrial membrane potential (Deltapsi) of boar spermatozoa. The substances from the Streptomyces isolates also swelled the mitochondria. The substances from isolates of Trichoderma harzianum Rifai and Bacillus pumilus damaged the cell membrane barrier function of sperm cells.

Air Microbiology↗
PubMed2000

Autoantibodies to glutamic acid decarboxylase in patients with therapy-resistant epilepsy.

BACKGROUND: Autoantibodies to glutamic acid decarboxylase (GAD-A) are present in type 1 diabetes and stiff man syndrome (SMS), and have also been reported in cerebellar ataxia. Epilepsy was present in 4 of 19 patients with SMS and GAD-A, implying that epilepsy sometimes is associated with anti-GAD autoimmunity. METHODS: The authors investigated the prevalence of GAD-A in patients with therapy-resistant localization-related epilepsy (n = 51) and generalized epilepsy (n = 49) by a radiobinding assay. The positive samples were confirmed by immunohistochemistry and immunoblotting of recombinant human GAD65. RESULTS: GAD-A were found in eight patients with localization-related epilepsy, whereas none of the patients with generalized epilepsy, other neurologic disorders (n = 38), or the control subjects (n = 48) had GAD-A. Two patients had high levels of GAD-A, similar to SMS, whereas six patients had significantly lower titers, characteristic of type 1 diabetes. The two patients with high levels of GAD-A had GAD-A both in serum and CSF by immunohistochemistry and immunoblotting. Both of them had longstanding therapy-resistant temporal lobe epilepsy but did not have diabetes. One had a history of autoimmune disease, whereas the other had serologic evidence of multiple autoantibodies without any clinical signs of autoimmune disease. CONCLUSIONS: GAD autoimmunity may be associated with refractory localization-related epilepsy.

Adolescent↗
PubMed2000

Adhesion molecules in multiple sclerosis: relation to subtypes of disease and methylprednisolone therapy.

OBJECTIVES: To determine levels of adhesion molecules in blood and cerebrospinal fluid (CSF) samples from patients with different subtypes and activities of multiple sclerosis (MS) and to assess the effect of intravenous methylprednisolone sodium succinate treatment on the levels of soluble adhesion molecules. DESIGN: The expressions of very late activation antigen 4 (VLA-4), lymphocyte function associated antigen 1 (LFA-1), vascular cell adhesion molecule 1 (VCAM-1), and intercellular adhesion molecule 1 (ICAM-1) were determined immunocytochemically, and levels of soluble VCAM-1, ICAM-1, and E-selectin, by means of enzyme immunoassay technique. The volumes of T2- and T1-weighted MS plaques and brain atrophy were determined by means of the semiautomatic magnetic resonance imaging (MRI) segmentation technique. SETTING: A university hospital in Finland. PATIENTS: One hundred subjects (71 patients with MS and 29 healthy control subjects). The subtypes of MS were relapsing-remitting (RRMS [n = 26]), secondary progressive (SPMS [n = 20]), and primary progressive (PPMS [n = 25]). RESULTS: In patients with RRMS and SPMS, the expressions of VLA-4 and LFA-1 on immune cells from blood were at least 1.5- to 3-fold higher than in controls (RRMS, P = .002 and P<.001, respectively; SPMS, P = .03 and P =.001, respectively). In RRMS, LFA-1 and ICAM-1 expression in blood was more up-regulated than in SPMS (P = .03 and P = .01, respectively). The expressions of adhesion molecules on CSF lymphocytes in RRMS and SPMS were of similar magnitude, but the proportions of CSF VLA-4- and LFA-1-expressing lymphocytes were 3- to 4-fold higher than in controls (P = .04 and P = .008, respectively). The levels of serum soluble VCAM-1 were higher in SPMS than in RRMS (P = .005) or PPMS (P = .04). Intravenous methylprednisolone treatment of patients with RRMS in exacerbation caused a significant reduction in the serum levels of soluble VCAM-1 and E-selectin (P<.001). In SPMS, the volumes of T2-weighted plaques correlated with the serum level of soluble ICAM-1 (r = 0.64; P = .03). CONCLUSIONS: Up-regulated adhesion molecules in blood and CSF indicate sustained potential for inflammation in the CNS throughout the clinical spectrum of MS. Therapies interfering with cell adhesion may be of key importance in suppressing MS.

Adult↗
PubMed2000

Interleukin-6 and interleukin-1 receptor antagonist in cerebrospinal fluid from patients with recent tonic-clonic seizures.

We have previously reported increased concentrations of interleukin (1L)-6 in CSF from patients with tonic-clonic seizures, where increased cytokine production most likely is a consequence of neuronal epileptic activity associated with seizures. The biological effects of IL-6 are mediated by other cytokines, which are studied here in addition to IL-6. The purpose of this study was to analyze levels of soluble cytokines from plasma and CSF from patients with newly developed tonic-clonic seizures. The concentrations of IL-6, IL-1 receptor antagonist (IL-1RA), IL-1beta, tumor necrosis factor (TNFalpha) and nerve growth factor (NGF) were measured from plasma and CSF from 22 patients with newly developed tonic-clonic seizures within 24 h from the seizure and 18 controls. The mean concentrations of IL-6 were significantly increased in CSF (P<0.001) and plasma (P<0.01) after tonic-clonic seizures, there was some indication of increased concentrations of IL-1RA and no significant change in NGF, IL-1beta or TNFalpha. Our study shows that cytokine network is activated in patients after recent tonic-clonic seizures. We provide evidence of intrathecal production of IL-6 associated with electrical seizure activity.

Adolescent↗
PubMed2000

The effect of PUVA on langerhans cells in rat oral epithelium photosensitized with systemic methoxsalen or topical trioxsalen.

BACKGROUND/PURPOSE: Ultraviolet-A radiation (UVA) of the oral mucosa after photosensitization with either systemic methoxsalen (8-MOP) or topical trioxsalen (TMP), i.e. mouth-PUVA, has been reported to be successful in the treatment of oral lichenoid lesions. In the case of PUVA treatment of skin disorders, local immune suppressive effects have been demonstrated, and the antigen presenting epithelial Langerhans cells (LCs) have been shown to be especially sensitive to ultraviolet treatments. Our aim was to compare the photobiological effects of PUVA in oral mucous membrane (OMM) using topical TMP or systemic 8-MOP photosensitization. METHODS: Rat OMM photosensitized with topical TMP or systemic 8-MOP was treated with PUVA using UVA doses of 1-8 J/cm2. The LCs were demonstrated in epithelial sheets of the treated OMM with ATPase staining. RESULTS: Both treatments caused a sim ilar, dose-dependent depletion of ATPase-positive LCs, with a maximal depletion of 80% or 73% with 8 J/cm2 at 2 days after irradiation as photosensitized with TMP or 8-MOP, respectively. This contrasts with earlier published findings in human skin, where topical TMP is an order of magnitude greater a sensitizer than 8-MOP, and PUVA-induced depletion of LCs occurs maximally 5 days after irradiation. CONCLUSION: The depletion of LCs of rat OMM after PUVA treatment is greater using topical TMP compared to systemic 8-MOP, but the difference is significantly smaller than reported earlier in human skin.

Administration, Oral↗
PubMed2000

Modified-release formulation of tizanidine in chronic tension-type headache.

The efficacy of the modified-release formulation of tizanidine (Sirdalud) was compared with placebo in a randomized, double-blind, parallel-group study of 138 women and 47 men, aged 18 to 79 years, with a history of chronic tension-type headache (IHS categories 2.2 and 2.3). The treatment period was 6 weeks preceded by a 2-week prerandomization period. The patients were randomly assigned to receive 6-mg Sirdalud, 12-mg Sirdalud MR, or placebo. The study medication was taken once per day, orally in the evening. Efficacy was measured by visual analog scale, the number of headache-free days, the daily duration of headache, and the use of paracetamol. The primary end point was the severity of daily headache derived from visual analog scale scores covering the last 2 treatment weeks. One hundred sixty patients (56 in the 6-mg group, 49 in the 12-mg group, and 55 in the placebo group) completed the study. The severity of the headache decreased similarly in the treatment groups and the placebo group. The visual analog scale values decreased from the prerandomization values by 53% in the 6-mg group, 48% in the 12-mg group, and 52% in the placebo group. The modified-release formulation of tizanidine in doses up to 12 mg taken in the evening is not superior to placebo in the treatment of chronic tension-type headache. The placebo effect was unexpectedly strong in the present study, supporting the view that psychophysiological mechanisms are of considerable importance in sustaining chronic tension-type headache.

Adrenergic alpha-Agonists↗
PubMed1999

Volumes of brain atrophy and plaques correlated with neurological disability in secondary progressive multiple sclerosis.

The objectives of the present study was to correlate the segmented magnetic resonance imaging (MRI) volumes of intracranial cerebrospinal fluid (CSF) spaces (expressing the extent of brain atrophy) and cerebral plaques with the neurological disability in secondary progressive multiple sclerosis (MS). Earlier studies have mainly correlated MS plaques and neurological disability measured by expanded disability status scale (EDSS). The data on the association between brain atrophy and EDSS or regional functional scoring scale (RFSS) are very limited. We measured the volumes of intracranial CSF spaces in 28 patients with secondary progressive MS using MRI, and semiautomatic segmentation software. The volumes of T1-weighted hypointense and T2-weighted hyperintense MS plaques were also measured. In multiple regression analysis, increasing volumes of total (P=0.006) and relative (P=0.005) intracranial CSF spaces were significantly associated with worsening neurological disability as expressed by EDSS. No associations were found between these intracranial CSF space volumes and total RFSS scores. The mean volume of T2-weighted plaques showed a tendency to associate with total RFSS score (r=0.40, P=0.03), but no correlations were detected between T1- or T2-weighted plaque volumes and EDSS. The application of a new segmentation technique in quantifying intracranial cerebrospinal fluid spaces allowed an exact and sensitive way of assessing brain atrophy. The associations between brain atrophy and neurological disability expressed by EDSS suggests that the effect of MS therapies should be evaluated by measurement of brain atrophy.

Adult↗
PubMed1998

Elevated levels of interleukin-6 may occur in cerebrospinal fluid from patients with recent epileptic seizures.

Experimental animal studies suggest the involvement of cytokines in epilepsy. We measured increased concentrations of interleukin-6 in four out of 15 cerebrospinal fluid samples from unmedicated patients with newly developed tonic-clonic seizures; plasma levels were also increased but to a lesser extent. Although the significance of cytokine production in relation to epileptic seizures is not known, it might be important for neuronal survival.

Adolescent↗
PubMed1998

Bioactive glass granules and polytetrafluoroethylene membrane in the repair of bone defects adjacent to titanium and bioactive glass implants.

An experimental animal model was used to investigate the effect of bioactive glass (BG) granules and nonresorbable polytetrafluoroethylene (PTFE) membrane on the repair of cortical bone defects adjacent to titanium and BG implants. Thirty-two Astra(R) (diameter 3.5 mm) dental implants were inserted bicortically and 42 conical BG implants (diameter 2.5-3.0 mm) monocortically, into fitted holes of rabbit tibia. Before implantation, a standardized bone defect was created by drilling an extra hole (diameter 3.0 mm) adjacent to each implant site. Twenty-eight defects were filled with BG granules (diameter 630-800 microm) (BG group) and 28 defects were left empty but covered with PTFE membrane (PTFE group). No material was used in 18 control defects (control group). Morphometrical evaluation with a digital image analysis system was used to measure bone repair as percentages of the defect area on scanning electron microscopy (SEM) and light microscopy pictures. Bone-implant contact was measured as percentages of the thickness of the cortical bone. At 6 and 12 wk, bone repair in defects in connection with titanium implants was 23.2% and 36.6% in the BG group, 23.2% and 32.4% in the PTFE group, and 47.2% and 46.2% in control defects. Corresponding figures for BG implants were 33.2% and 40.1% in the BG group, 16.6% and 33.5% in the PTFE group, and 25.7% and 54.9% in control defects, BG granules and new bone together filled 82.7% and 68.5% of the defect area adjacent to titanium implants, and 75.9% and 74.4% of the defect adjacent to BG implants at 6 and 12 wk, respectively. Better bone-implant contact was achieved at the defect side with BG than titanium implants (77.0% versus 45.0% at 12 wk). The results indicate that BG granules are useful in treatment of bone defects adjacent to dental implants. BG coating of the implant seems to improve osseointegration in the defect area.

Journal Article↗
PubMed1998

A reversible neuronal antibody (anti-Tr) associated paraneoplastic cerebellar degeneration in Hodgkin's disease.

Paraneoplastic cerebellar degeneration (PCD) has been associated with a variety of neoplasms, most commonly with gynecologic tumors, breast cancer, small cell lung cancer, and Hodgkin's disease (HD). In some patients PCD is associated with circulating antineuronal antibodies like anti-Hu, anti-Yo or anti-Ri. Previously, only 5 patients with a new antineuronal antibody called anti-Tr, proposed to be specific for HD, have been reported. We describe 1 further patient with HD and reversible PCD with a decline in anti-Tr antibody titers in cerebrospinal fluid and serum corresponding to the improvement of clinical symptoms. At the present time the immunoreactive pattern observed in rat cerebellum is the only way to identify anti-Tr antibodies and differentiate them from other antibodies that immunoreact with the Purkinje cells.

Adult↗
PubMed1998

The mitochondrial toxin produced by Streptomyces griseus strains isolated from an indoor environment is valinomycin.

Actinomycete isolates from indoor air and dust in water-damaged schools and children's day care centers were tested for toxicity by using boar spermatozoa as an indicator. Toxicity was detected in extracts of four strains which caused a loss of sperm motility, and the 50% effective concentrations (EC50) were 10 to 63 ng (dry weight) ml of extended boar semen-1. The four strains were identified as Streptomyces griseus strains by 16S ribosomal DNA and chemotaxonomic methods. The four S. griseus strains had similar effects on sperm cells, including loss of motility and swelling of mitochondria, but we observed no loss of plasma membrane integrity or depletion of cellular ATP. None of the effects was observed with sperm cells exposed to extracts of other indoor actinomycete isolates at concentrations of >/=5,000 to 72,000 ng ml-1. The toxin was purified from all four strains and was identified as a dodecadepsipeptide, and the fragmentation pattern obtained by tandem mass spectrometry was identical to that of valinomycin. Commercial valinomycin had effects in sperm cells that were identical to the effects of the four indoor isolates of S. griseus. The EC50 of purified toxin from the S. griseus strains were 1 to 3 ng ml of extended boar semen-1, and the EC50 of commercial valinomycin was 2 ng ml of extended boar semen-1. To our knowledge, this is the first report of the presence of ionophoric toxin producers in an indoor environment and the first report of valinomycin-producing strains identified as S. griseus.

Air Microbiology↗
PubMed1997

Bioactive glass and calcium carbonate granules as filler material around titanium and bioactive glass implants in the medullar space of the rabbit tibia.

The effect of bioactive glass (BG) and calcium carbonate (CC) granules on bone formation around titanium and BG implants projecting into the medullary space of rabbit tibia was studied. The bone marrow tissue was removed and the medullary space was filled either with BG or CC (Biocoral) granules (phi 630-800 microns). Conical titanium and BG implants were inserted into the holes drilled in compact bone using the press fit-technique. Histomorphometry was used to measure the bone-biomaterial area in a 1.0 mm wide zone around the head of the implant and the contact between formed bone and implant. Significantly larger bone-biomaterial area was obtained around titanium implants using BG than CC granules while no difference was found in connection of BG implants. Better bone-implant contact was achieved with BG implants than with titanium implants regardless of the type of granules used. The results indicate that BG may prove to be useful as filler and coating material in connection of implants projecting into bone cavities.

Animals↗
PubMed1997

A 5-year prospective clinical study of Astra Tech dental implants supporting fixed bridges or overdentures in the edentulous mandible.

In a 5-year prospective clinical study, 155 endosseous implants were installed in the mandible anterior to the mental foramina in 33 edentulous patients (13 males and 20 females). Usually 6 implants were installed for fixed prostheses (FP), 13 patients with 77 implants, and 4 implants for overdentures (OD) with a Dolder bar, 20 patients with 78 implants. At the time of abutment connection 1 implant in 2 patients was found to be loose and removed. However, in both these patients overdentures were successfully placed on the remaining 3 implants. Narrow-beam radiography was used for radiological evaluation. The mean (SD) total marginal bone loss in 5 years was 0.48 (0.38) mm (0.36 (0.22) mm in the FP group and 0.56 (0.45) mm in the OD group). Very few complications were reported during the 5 years, most of them being related to the superstructures. The overall cumulative implant survival rate was 98.7% (100% in the FP group and 97.4% in the OD group). The survival rate of the superstructures was 100%. The present study has demonstrated that Astra Tech implants offer reliable and predictable medium-term support for fixed prostheses and overdentures in the edentulous mandible.

Adult↗
PubMed1996

The effect of ascorbate and ubiquinone supplementation on plasma and CSF total antioxidant capacity.

Free radicals are thought to be involved in the onset of neuronal disturbances such as Alzheimer's disease, Parkinson's disease, and neuronal ceroid lipofuscinosis. It is also assumed that they play a role in cerebral injury caused by ischemia or trauma. Plasma and cerebrospinal fluid (CSF), Total (peroxyl) Radical-trapping Antioxidant Parameter (TRAP), and the known antioxidant components of TRAP, for instance, ascorbic acid, uric acid, protein sulfhydryl groups, tocopherol, and ubiquinol were analyzed and the remaining unidentified fragment was calculated in five healthy volunteers before and after 4 weeks of ascorbate and ubiquinone (Q-10) supplementation. In CSF, TRAP was significantly lower than in plasma. The major contributor to plasma's antioxidant capacity was uric acid (UA), whereas in CSF it was ascorbic acid (AA). In CSF, AA concentrations were four times higher than in plasma. Oral supplementation of AA (500 mg/d first 2 weeks, 1,000 mg/d following 2 weeks) and Q-10 (100 mg/d first 2 weeks, 300 mg/d following 2 weeks) induced a significant increase in plasma AA and Q-10. Surprisingly, in spite of the high lipophilicity of Q-10, its concentration did not change in CSF. The supplementation of AA increased its concentration in CSF by 28% (p < .05). However, the increase in AA did not result in an increase in CSF TRAP. This indicates that AA had lost one-third of its radical trapping capacity as compared to that in plasma. The facts that AA is the highest contributor to CSF TRAP and its effect on TRAP is concentration dependent could indicate that the peroxyl radical-trapping capacity of CSF is buffered by AA.

Adult↗