Search Results
You are looking at 1 - 6 of 6 items for
- Author or Editor: Cs. Bognár x
- Refine by Access: All Content x
In water quality research the interest in online biofilm monitoring techniques has recently increased significantly. Christiani et al. (2008) presented a simple electrochemical technique to monitor electro-active biofilm in soil, based on the cathodic polarisation of stainless steel electrodes. Authors present an improved method, in which stainless steel was replaced by copper. By using copper-zinc electrodes authors have shown difference in the electrical potential between sterilized and native soils even at low moisture content.
Abstract
Long head of the biceps (LHB) is an intra-articular tendon component of the shoulder joint. The function of this tendon is complex. First, it is an origin of flexion in upper limb, and second it plays role in joint stabilisation during shoulder movements. Histological type of tendon tissues is connective tissue. The mechanical behaviour of connective tissue is primarily determined by the composition and organisation of collagens. In tendons, type I collagen is the principal structural element of the extracellular matrix, which acts to transmit force between bones or bone and muscle. Owing to the special localisation of this tendon, the intra-articular mechanical forces affect it to a considerable extent. The LHB is known as a source of pain in pathologic states of the shoulder joint. The goal of this study was to establish the calorimetric standards of the LHB in different ages, and to observe the changes of thermal properties of collagen during lifetime. LHB samples were taken from 38 cadavers (between ages 0 and 90 years) without macroscopic sign of shoulder pathology. DSC analyses were performed with SETARAM Micro DSC-II. The thermal denaturation parameters varied between T m (°C): 57, ΔH (J/g): 0.26 (age: 0 year) and T m (°C): 62.92, ΔH (J/g): 1.28 (age: 90 years). The ageing of collagenous tendon tissue can be clearly followed in changes of thermal denaturation properties. The knowledge of the ageing of normal collagen provides a good basis to analyse further the LHB pathology.
Twenty-six Bifidobacterium strains were isolated from human faeces. Seven strains were identified as B. bifidum, 4 strains as B. breve, 10 strains as B. longum, 2 strains as B. pseudocatenulatum and 3 strains as B. dentium by 16S rDNA analysis. The isolates from human origin showed strong adherence to the human tissue cultures. Three out of the 12 tested isolates repressed the growth of enteropathogenic bacteria. Utilisation of 9 commercially available oligosaccharides was tested by both Bifidobacteria and enteropathogens. Pro-, pre- and synbiotic food was made. Their effect was evaluated in in vivo feeding experiments, where healthy and antibiotic treated mice were used as test animals. During the four-week feeding period the composition of the colonic microbiota of the healthy mice did not change characteristically in any feeding group. However, the microbiota of mice in which it had been killed by antibiotic treatment was recovered by feeding with synbiotic food.
DSC analysis of human fat tissue in steroid induced osteonecrosis
A preliminary study
Abstract
Osteonecrosis (ON) of the femoral frequently occurs after steroid medication. One of the final pathways leading to steroid induced ON is thought to be pathologic fat metabolism. The pathobiological mechanism underlying the induction of fat metabolism outslides by steroids leading to ON has not been fully elucidated. The purpose of this study was to examine the intraoperative obtained gluteal fat tissue from ON patients with histology, gas chromatography (GC) and differential scanning calorimetry (DSC) and to compare them with otherwise healthy patient’s samples. The histological sections showed no significant differences compared with the control group. GC revealed that fraction of saturated fatty acids decreased in ON samples from mean values of controls of 24% to 21, the polyunsaturated fraction from 20 to 14%. The monounsaturated acids showed an increase from mean rate of 52% of the controls to 65% of steroid treated samples. DSC curves correlate with chromatographic analysis of the tissue fatty acids (Steroid treated, heating between 0–100°C: T m=5.7°C, ΔH= −15.8J/g−1; heating between −20–100°C: Tm= −9.96 and 5.85°C, ΔH= −59.17 and −16.2 J g−1. Non-necrotic, heating between 0–100°C: two separable transition with Tm=5.7 and 9.9°C, total ΔH= −20.8 J g−1; heating between −20–100°C: Tm= −10.9 and 4.95°C, total ΔH= −75.8 J g−1.) Our preliminary findings are rather tendentious. Further investigations are needed with higher sample rate and under other anamnestic circumstances too.
Abstract
Avascular necrosis of human femoral head (ANFH) causes incongruity in the joint that leads to disability in patients requires total hip arthroplasty (THA). Several etiological factors of ANFH have been proposed in the literature but there are cases of idiopathic origin. We observed macroscopic variation in quality of the subcutaneous fat tissue in patients with ANFH compared to patients with osteoarthritis or hip fracture during THA procedures. The samples were analysed by histology, gas chromatography (GC) and differential scanning calorimetry (DSC). Conclusion: the alteration in the fatty acid profile did not cause histological changes, however we could detect biochemical changes using DSC and GC.
Abstract
The osteonecrosis or avascular necrosis of the antero-superior part of the human femoral head (ANFH) often causes incongruity in the hip joint and leads to severe pain and disability in middle aged patients. This abnormality often requires surgical intervention, mainly total hip arthroplasty (THA). The possible pathomechanisms of ANFH are fat embolism, arterial occlusion, fatty necrosis of osteocytes and intraosseous hypertension. Factors have been proposed in the literature that can lead to this condition are alcohol abuse, steroid therapy, metabolic changes, dyslipidaemia. In some case we can not verify any factor; these are the so called idiopathic ANFH cases. We observed macroscopic variation in colour and consistency of the subcutaneous fat tissue in patients with ANFH compared to osteoarthritis or hip fracture during THA procedures. Subcutaneous fat tissues during THA from a patient with ANFH due to alcohol abuse were compared with an otherwise healthy patient who underwent surgery due to traumatic hip fracture. No histological changes were notified in the size; shape of adipocytes and in the cells of the septae of the connective tissue. Gas chromatography showed that the patient with alcoholic ANFH had less long chain fatty acids. DSC revealed, that in case of non-necrotic sample as a reference, during heating between 0–100°C two separable transitions are with T m=5.7 and 9.9°C, total ΔH= −20.8 J g−1. In −20–100°C range endotherms with T m= −10.9 and 4.95°C, total ΔH= −75.8 J g−1 could be detected. In case of alcohol-induced avascular necrosis we have found endotherms between 0–100°C with: T m=7.3°C, total ΔH= −26.9 J g−1, and heating between −20–100°C: T m= −0.25°C, total ΔH= −103.3 J g−1 thermal parameters. The alteration in the fatty acid profile did not cause histological changes, but we were able to detect it with analytical methods e.g. DSC and gas chromatography.
