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Biomedical subjects

R Mattila

Publications and source records attributed to R Mattila.

10 recordsLinked to original sources
PubMed2004

Surface porous fibre-reinforced composite bulk bone substitute.

The aim of this study was to describe and evaluate the significance of a porous surface with bioactive glass granules (S53P4) covering an artificial bulk material based on polymethylmetacrylate (PMMA) and fibre-reinforced composite (FRC) technology. Effort was focused particularly on characters of the porous surface and biomechanical properties of the material in vitro , and test in vivo the implant in reconstruction in an experimental long bone segment defect model. The defect, 10 mm in length, created in the shaft of rabbit tibia, was reconstructed by the implant and fixed by intramedullary K-wires. The implant was incorporated within 4 weeks by new bone growth from the host bone covering particularly its posterior surface and cortex/implant junctions with bridging trabecular bone. Later, at 8 weeks, new bone was found also at the cortex/implant interface and in the medullary canal of the implant. Histometric measurements revealed direct bone/implant surface contact in 34% at the interface. Bioactive glass granules in the porous surface evoked the most direct contact with bone. The implants manufactured from PMMA only served as a control group, and showed significantly lower osteoconductive properties. Biomechanical measurements in vitro of fibre-reinforced PMMA specimens revealed values for bending strength and the flexural modulus to match them to human bone. This artificial bulk bone material based on PMMA/FRC technology seems to have proposing properties to be used as a bone substitute on load-bearing conditions.

Bone Substitutes↗
PubMed2003

Effectiveness of multidisciplinary lifestyle intervention for hypertension: a randomised controlled trial.

Lifestyle factors like weight, alcohol consumption, salt intake and physical activity have shown to be important in treating hypertension. There have been made some randomised trials about the effects of lifestyle interventions, but the numbers of patients have been relatively small and the durations of follow-ups have been short. No controlled trials assessing the effects of lifestyle intervention in a rehabilitation setting have been reported. In this study, the effects of multidisciplinary lifestyle intervention in rehabilitation centres among middle-aged hypertensive employees were described. A total of 731 hypertensives from 45 worksites were randomised to lifestyle intervention in a rehabilitation centre or to usual care in an occupational or primary health-care centre for 12 months. Standard measurements were conducted before the intervention and 1-year later. Blood pressure (BP) levels were clearly reduced in the intervention group, while only minor changes were observed in the control group. The net changes between the two groups both for systolic and diastolic BPs were -2.1 mmHg (95% confidence intervals (CI) -4.0 to -0.1) and -1.5 mmHg (95% CI -2.6 to -0.4), respectively. The net changes were greater among men than women. The multidisciplinary lifestyle intervention in a rehabilitation centre setting produced significant reductions in BP among middle-aged employees with hypertension.

Cardiovascular Diseases↗
PubMed2001

Characterization of Mycobacterium bohemicum isolated from human, veterinary, and environmental sources.

Chemotaxonomic and genetic properties were determined for 14 mycobacterial isolates identified as members of a newly described species Mycobacterium bohemicum. The isolates recovered from clinical, veterinary, and environmental sources were compared for lipid composition, biochemical test results, and sequencing of the 16S ribosomal DNA (rDNA) and the 16S-23S rDNA internal transcribed spacer (ITS) regions. The isolates had a lipid composition that was different from those of other known species. Though the isolates formed a distinct entity, some variations were detected in the features analyzed. Combined results of the phenotypic and genotypic analyses were used to group the isolates into three clusters. The major cluster (cluster A), very homogenous in all respects, comprised the M. bohemicum type strain, nine clinical and veterinary isolates, and two of the five environmental isolates. Three other environmental isolates displayed an insertion of 14 nucleotides in the ITS region; they also differed from cluster A in fatty alcohol composition and produced a positive result in the Tween 80 hydrolysis test. Among these three, two isolates were identical (cluster B), but one isolate (cluster C) had a unique high-performance liquid chromatography profile, and its gas liquid chromatography profile lacked 2-octadecanol, which was present in all other isolates analyzed. Thus, sequence variation in the 16S-23S ITS region was associated with interesting variations in lipid composition. Two of the isolates analyzed were regarded as potential inducers of human or veterinary infections. Each of the environmental isolates, all of which were unrelated to the cases presented, was cultured from the water of a different stream. Hence, natural waters are potential reservoirs of M. bohemicum.

Aged↗
PubMed1999

Hospital water supply as a source of disseminated Mycobacterium fortuitum infection in a leukemia patient.

Nosocomial acquisition of Mycobacterium fortuitum led to a disseminated infection in a leukemia patient. A linkage to showerhead water was supported by molecular typing of clinical and environmental isolates. Contamination of the hospital water system with microbes that are relatively resistant to common sanitation processes poses an increased risk of infection to neutropenic patients.

Cross Infection↗
PubMed1983

Epidermolysis bullosa simplex. A new histologic subgroup.

Two patients with a new mechanobullous disease are described. The trauma-induced bullae were present at birth. The nails were deformed in both cases. Both patients were isolated cases; so far, the inheritance pattern is not known. The histologic picture was unique. The keratinocytes were dyskeratotic, enlarged, and had atypical mitoses on light microscopy of neonatal biopsy specimens. Electron microscopically the defect occurred in the tonofilaments, which formed round clumps. The blister formation took place in the lower part of the epidermis.

Cytoskeleton↗