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Biomedical subjects

M Albrecht

Publications and source records attributed to M Albrecht.

At least 127 records · Page 7Linked to original sources

[The addition of ethyl alcohol to the irrigating fluid. Monitoring fluid absorption during transurethral resection of the prostate].

The absorption of irrigation solution during transurethral prostatic resection may lead to the life-threatening condition of the so-called TUR syndrome. For a long time no early recognition procedure was easily and routinely available. This study was set up to investigate the effectiveness of ethanol as an early indicator of beginning absorption, as described by Hulten. Ethanol was therefore added to the irrigating fluid as a marker, and alcohol concentrations were measured in the exhaled breath. METHODS. For measurement of alcohol an Alcotest monitor 7110, Drägerwerk (Lübeck, FRG) was used. In preliminary experiments with 13 healthy volunteers the lowest amount of measurable i.v.-administered 2% Ringer-ethanol solution was found to be about 200 ml. The irrigating fluid used was a 2% ethanol-mannitol/sorbitol solution. RESULTS. The control of breath and blood alcohol levels in 10 patients undergoing transurethral bladder surgery showed that there was no absorption of alcohol across the internal bladder lining. Of 52 patients, who had to undergo transurethral prostatic resection, 23 had positive breath alcohol values of up to 0.81/1000. In 6 patients the blood alcohol levels only were elevated (max. 0.18/1000). In 23 other patients no increased blood or breath alcohol levels were detectable. The negative breath alcohol levels in 6 patients were most probably attributable to low breath volumes due to lack of cooperation caused by pre- and/or intraoperative sedation. There were no significant changes in central venous pressure, mean arterial pressure or heart rate even at the time of maximal alcohol levels, compared with initial values. These parameters thus cannot be used for the early recognition of beginning absorption. Simultaneous monitoring of serum sodium concentrations revealed significant decreases at the time of maximal breath alcohol levels. Yet, the first indication of beginning absorption was always a positive alcohol level. Serum sodium changes followed later with increasing alcohol levels. Sodium concentration did not drop before a positive alcohol level was measured in any of these cases. CONCLUSION. It was thus proven that the addition of ethanol to the irrigating fluid and monitoring of the patient's exhaled breath with the Alco-testmonitor is a simple, non-invasive system that can be routinely used for early detection of absorption during transurethral prostatic resection. Adequate adjustment of the further course of the operation was possible. The dreaded TUR syndrome did not develop in any of the patients monitored in this way.

Aged↗

Osteoarthritic changes in canine articular cartilage, subchondral bone, and synovium fifty-four months after transection of the anterior cruciate ligament.

Anterior cruciate ligament transection (ACLT) in the dog results in osteophyte formation and in morphologic, metabolic, biochemical, and biomechanical changes in the articular cartilage of the unstable knee that mimic those of human osteoarthritis (OA). However, in dogs studied up to 2 years after ACLT, the changes have appeared to be self-limiting, which has led to the suggestion that this is a model of cartilage damage and repair, rather than of OA. To ascertain whether changes in articular cartilage and subchondral bone of dogs subjected to ACLT lead to progressive changes of OA, we studied 3 dogs for 54 months after ACLT. Arthrotomy was performed in the dogs to visualize and then transect the anterior cruciate ligament. When the dogs were killed, full-thickness ulceration of the articular cartilage was seen on the medial femoral condyle and tibial plateau of the unstable knee, while cartilage in other regions was thicker than that of the contralateral knee, consistent with hypertrophic cartilage repair. Synovial infiltration by mononuclear cells was not more severe than that seen in dogs killed at earlier intervals after ACLT, although gross fibrotic thickening of the capsule was apparent in each dog. Histomorphometric studies revealed a marked increase in subchondral bone volume and active bone formation. These findings show that the changes that develop in the canine knee joint after ACLT are progressive and are unambiguously those of OA.

Animals↗

Natural history of Coxsackievirus B3-induced myocarditis in ACA/Sn mice: viral persistence demonstrated by quantitative in situ hybridization histochemistry.

Enteroviruses are considered to be the major aetiological agents of myocarditis in humans. Recent in situ hybridization studies on endomyocardial biopsies and autopsy hearts indicate that enterovirus RNA can be detected (pattern of persistent infection) not only in acute myocarditis (pattern of acute infection), but also in chronic dilated cardiomyopathy. Our experimental studies on murine coxsackievirus B3 myocarditis provided evidence that persistent infection may also occur in mice. Quantitative in situ hybridization and immunohistochemistry as well as electron microscopical in situ hybridization experiments were performed on ACA/SnJ mice 3-30 days after infection. The pattern of acute infection (days 3-9 p.i.) is characterized by rapid progression of myocardial lesions, an increasing number of inflammatory cells and a high number of infected myocytes. Hallmarks of the persistent pattern (days 15-30 p.i.) are reduced inflammation, reduced numbers of persistently infected cells and a slow progression of myocardial lesions. Infection is primarily restricted to degenerated, atrophic myocytes and to fibroblasts.

Animals↗

[Relationship between the caries status and metabolic imbalance in diabetics].

The dental clinical examination of 1600 (815 insulin dependent of type 1 and 761 non-insulin dependent of type 2 respectively) patients cared of because of diabetes mellitus was carried out and an answer to the question was sought for whether the condition of the teeth does change according to he type of the metabolic disturbance of the diabetic, the time of its manifestation, its setting, the manner of therapy, the family occurrence of the illness and the mouth hygiene, respectively. According to examination results, greater edentulousness with diabetes over 30 years showed a positive interdependence according to the confirmance time of diabetes. On the other hand, with diabetic of better setting there were less teeth with caries or removed ones and the DMF-T average was lower than with patients with worse diabetes setting. No independence was found in the development of the DMF-T average and the caries conditions, respectively, if diabetes occurred in the family history and according to the type of diabetes.

Adolescent↗

[Dental enamel hardness tests in diabetics].

The authors studied by in vivo methods (Fosse et al. 1986) the microhardness of dental enamel in diabetic patients compared to healthy persons. No differences of enamel microhardness values between diabetics and healthy persons, neither by longer diabetes duration nor by worse diabetes attitude have been found.

Adolescent↗

Anterior (cranial) cruciate ligament transection in the dog: a bona fide model of osteoarthritis, not merely of cartilage injury and repair.

To help elucidate the longterm outcome in the unstable knees of dogs that have undergone anterior cruciate ligament (ACL) transection, conventional radiography, gait analysis and magnetic resonance imaging (MRI) were performed serially on 3 dogs over a 45-month period after ACL transection. Gait analysis showed that vertical forces generated by the cruciate deficient leg were smaller than those produced by the contralateral leg, but the decrease in loading was not progressive and clinical findings did not suggest that the dogs developed pain in the unstable limb. Despite progressive osteophytosis and subchondral sclerosis, as seen on plain radiographs, MRI demonstrated that articular cartilage in the unstable knee was thicker than that in the contralateral knee 36 months after ACL transection. Nine months later, however, striking focal loss of articular cartilage was seen in the unstable knee of each dog. Our study, which provides the first longterm observations of the changes in the unstable knee after ACL transection, shows that they represent progressive osteoarthritis and emphasizes that a prolonged phase of cartilage hypertrophy may precede the stage of cartilage breakdown.

Animals↗

[Testing of dental enamel hardness by an in vivo method].

The authors studied the microhardness of sound enamel in healthy persons, with in vivo measurements by the Vickersdiamond, used in earlier tests. The evaluation of the impressions was done by a modificated image-analysis method. The method by Fosse et al, for in vivo microhardness measurements can bring good results in practice according to the investigations. The image-analysis makes the evaluation essentially easier. The intraindividual use of this method in longitudinal examinations eliminates the sources of error occurring at horizontal comparisons.

Adult↗

[Caries status in diabetic patients].

Clinical dental examination of 1600 diabetics (815 type 1 insulin dependent and 761 type 2 non-insulin dependent patients) has been performed according to the WHD criteria. According to examination results higher DMF mean value, less uncared of teeth with caries (D) and, in the age group of 19 years and above 30 years, more edentulousness has been found than with healthy individuals. The number of filled and crowded teeth (F) below the age of 35 years in diabetics (p 0.0001), above 45 years in the control group (p 0.0001) was higher. Concerning cared of teeth there was no deviation in the number of filled teeth between diabetic and healthy individuals whereas the number of crown covered teeth was higher with diabetics. (p 0.01). As to the distribution of individuals with healthy teeth and toothless ones it was found characteristic that while among diabetic individuals but 1%, in the control 1.4% possessed retained healthy teeth. The number of completely toothless individuals was higher (11.83%) with diabetics than with healthy individuals (2.25%).

Adolescent↗

MRI demonstration of hypertrophic articular cartilage repair in osteoarthritis.

Transection of the anterior cruciate ligament in the dog produces changes in the unstable joint typical of osteoarthritis, although full-thickness cartilage ulceration is rare. Information concerning the late fate of the cartilage after transection is meager. In the present study magnetic resonance imaging (MRI) was used to evaluate cartilage abnormalities 3 years after transection. Plain radiographs of the osteoarthritic and contralateral knees were obtained serially. MRI was performed 3 years after anterior cruciate ligament transection, at which time all three animals exhibited knee instability. Radiographs of the osteoarthritic knees showed osteophytes and subchondral sclerosis with progression between 2 and 3 years. On MRI, articular cartilage margins in the knee were indistinct, and the cartilage was thicker than that in the contralateral knee (maximum difference = 2.7 mm). This increase in thickness is consistent with biochemical data from dogs killed up to 64 weeks after creation of knee instability, which showed marked increased in cartilage bulk and in proteoglycan synthesis and concentration. The findings emphasize that increased matrix synthesis after anterior cruciate ligament transection leads to functional cartilage repair sustained even in the presence of persistent alteration of joint mechanics.

Animals↗

Embryotoxic/teratogenic potential of halothane.

The embryotoxic/teratogenic potential of halothane was evaluated on the basis of available data obtained in an extensive literature search. It was found that halothane induced ultrastructural visible changes in the offspring of rats exposed to concentrations of 10 ppm during gestation. These consisted of degenerative changes in the cerebral cortex and, in particular, the weakening of cell membranes and the vacuolisation of the Golgi-complex. Macroscopically visible morphological changes were seen in rats only after exposure to concentrations equivalent to 320-fold (1600 ppm) the MAK value (maximum concentration value at the workplace). Furthermore, behavioural disorders were seen when exposure to concentrations greater than or equal to 10 ppm occurred during gestation and after parturition. In mice, only macroscopical investigations were performed. The first disturbances scored were only visible as retardation in the offspring, and occurred after exposure to concentrations of halothane 200-fold (1000 ppm) the MAK-value. In the rabbit, anaesthetic concentrations of 22000 ppm halothane did not result in an embryotoxic/teratogenic effect. The individual epidemiological findings in humans were discussed controversially. The studies are inconclusive in establishing an embryotoxic/teratogenic risk following sole exposure to halothane at the MAK level, since mixed exposures occurred and data on the concentrations of halothane in the inhaled air were missing. Therefore, the decision on whether halothane can impair intrauterine development is primarily based on the animal experimental findings. As long as a threshold value has not been established for the observed lesions, halothane should not be inhaled during pregnancy.

Abnormalities, Drug-Induced↗

Structures of compounds with antigonadotropic activity obtained by in vitro oxidation of caffeic acid.

Two new cyclolignan derivatives were isolated by HPLC from the mixture of substances obtained after oxidation of caffeic acid with KMnO4. Their structures were elucidated by spectroscopic methods as 2,3-dicarboxy-6,7-dihydroxy-1-(3', 4'-dihydroxy)-phenyl-1, 2-dihydronaphthalene (1) and 3-carboxy-6,7-dihydroxy-1-(3', 4'-dihydroxy)-phenylnaphthalene (2). Compounds 1 and 2 exhibit antigonadotropic activity as do the extracts of crude drugs of Lycopus europaeus and Lithospermum officinale after oxidation by plant enzymes.

Animals↗

Effect of naproxen sodium on the net synthesis of glycosaminoglycans and protein by normal canine articular cartilage in-vitro.

The effects of the non-steroidal anti-inflammatory drug, naproxen sodium, on the metabolism of normal canine articular cartilage has been examined. At a concentration approaching that achieved in synovial fluid of patients treated with the drug (i.e. 30 micrograms mL-1) naproxen sodium had no significant effect on net synthesis of either glycosaminoglycans or protein in organ cultures of femoral condylar cartilage, nor did it increase the proportion of newly synthesized glycosaminoglycans recovered from the culture medium, suggesting that it had no direct effect on the integrity of the extracellular matrix.

Animals↗

[Patterns of acute and persistent infections in enteroviral heart diseases].

Enteroviruses are considered as the major etiologic agents of myocarditis in humans. Recent in situ hybridization studies on endomyocardial biopsies indicate that not only in acute myocarditis (pattern of acute infection), but also in chronic dilated cardiomyopathy enterovirus RNA can be detected (pattern of persistent infection). Our experimental studies on murine coxsackievirus B3 myocarditis provided evidence that persistent infection occurs also in mice. Quantitative in-situ hybridization and immunohistochemistry as well as electron microscopic in situ hybridization experiments were performed on ACA/SnJ mice three to thirty days after infection. The pattern of acute infection (days 3-9 p.i.) is characterized by rapid progression of myocardial lesions, an increasing number of inflammatory cells and a high number of infected myocytes. Hallmarks of the persistent pattern (day 15-30 p.i.) are reduced inflammation, reduced numbers of persistently infected cells and a slow progression of myocardial lesions. Infection is primarily restricted to degenerated, atrophic myocytes and to fibroblasts.

Acute Disease↗

Production of cerium-apatite in sound and carious dental enamel under in vitro conditions.

Incipient dental caries--according to up-to-date concepts in dental research--means a demineralization without cavity formation. At this stage the carious process is reversible, and remineralization can be achieved in the presence of locally applied fluorides. In chrystalchemical experiments, however, by treating natural apatites with lanthanides, [Ce, La, Pr, Nd, Sm, Eu, Tb ... Y, Sc] a more resistant complex could be developed. In this study extracted human molar teeth were kept for 60 days in Cerium (III)-nitrate solution, in order to investigate the incorporation of Ce3+ into human sound and carious enamel by light-microscopic-, and electron microprobe methods. Ce3+ was incorporated in sound enamel as well as into the incipient carious lesion, showing the histological characteristics of a remineralizing lesion. The mean values of the microprobe analysis data showed an increase in Ce3+ changing place with the Ca2+ the developing cerium-apatite being more hard and resistant from a mineralophysical point of view.

Apatites↗

Comparative histopathological studies in oral lichen planus.

A comparative histological study of 100 cases of oral lichen planus, originating from Cuba and Hungary, was carried out in order to define some characteristics, especially epithelial dysplasia and their possible relation with the clinical types. The ratio of dysplastic changes found was 11%, the presence of more than one layer of cells having a basaloid appearance being the most frequent feature, followed by loss of polarity of basal cells. In relation with the clinical types the ratio of dysplasia was higher in atrophic/erosive cases (25%).

Adolescent↗

[Crystallo-chemical problems of dental enamel and new possibilities of in vitro remineralization].

Incipient dental caries according to up-to-date concepts in dental research--means a demineralization without cavity formation. At this stage the carious process is reversible, and remineralization can occur in the presence of locally applied fluorides. In crystal chemical experiments, however, by treating natural apatites with lanthanides (Ce, La, Pr, Nd, Sm, Eu, Tb...Y, Sc) a more resistant complex could be developed. In this study extracted human molar teeth were kept for 60 days in Cerium (III)-nitrate solution, in order to investigate the incorporation of Ce3+ into human sound and carious enamel by light-microscopic-, and electron microprobe methods. Ce3+ was incorporated in sound enamel as well as into the incipient carious lesion, showing the histological characteristics of a remineralizing lesion. The mean values of the microprobe analysis data showed an increase in Ce3+ changing place with the Ca2+ the developing cerium-apatite being more hard and resistant from a mineralo-physical point of view.

Crystallization↗