Biomedical subjects
Publications and source records attributed to E Müller.
The nucleotide sequences of nine clones, pKA191/1-4 from Drosophila kitumensis and pMR190/1-5 from D. microlabis, were determined. They represent a tandemly arranged and highly repetitive satellite DNA family, KM190, which is specific for the two species.
Structural and functional analyses were carried out to compare transcription termination and intergenic spacer organization between the two heterogeneous ribosomal DNA size classes of Ascaris lumbricoides. By performing mung bean nuclease mapping in vivo, we localized the 3' end of the mature 26S rRNA to the same position in both forms. This site coincides with the in vivo and in vitro transcription termination site of the 40S-precursor rRNA from both rDNA size classes. We demonstrate that the 3' boundary of sequences necessary for faithful transcription termination extends 35 bp beyond the end of the 26S rRNA gene and that these sequences are perfectly conserved within the two size classes. The intergenic spacers of both rDNA size classes have been completely sequenced; they are 2410 bp and 1937 bp long and show a sequence homology of 92.8%. There is no evidence for the presence of reiterated termination sites or promoters within the relatively short intergenic spacers of the two rRNA gene classes.
Blood samples of 135 residents living near the estuary of the Elb River (Schleswig-Holstein, Germany) were analyzed for organochlorines (e.g., beta-hexachlorocyclohexane (HCH) (less than 0.5-22.9 ng/ml), benzene hexachloride (HCB) (0.8-55.2 ng/ml), DDE (less than 0.5-29.2 ng/ml) and for mercury (Hg, n = 44) (1.1-79.2 ng/ml). It was the first time that octachlorostyrene (OCS) (n.d.-9.2 ng/ml) could be detected in Germans. The pollutants were determined by means of capillary gas chromatography and atomic absorption spectroscopy, respectively. Covariance analysis and log-linear models revealed correlation between increasing age and blood concentrations of HCB, beta-HCH, DDE and OCS, between relative body weight and HCB or DDE, between locality and all pollutants analyzed, and, finally, between fish consumption and OCS and Hg. Regarding the influence of locality on the body burden of pollutants it may be assumed that additional routes of uptake, e.g., via drinking water or air, might be important.
Five Italian families with recurrence of cases of Charcot-Marie-Tooth disease (type Ia) were analysed using three closely linked DNA probes that detect polymorphisms in the region 17p11.2. The probe pVAW409R3 detected the presence of a duplication in all the affected subjects, but not in the subjects with normal electromyographic (EMG) findings. This observation confirms previous data indicating the association of the duplication with the disease, suggesting that, at least in populations of European origin, the duplication might be the molecular feature diagnostic of the pathological trait.
1,2-Dioxetanes are efficient sources of triplet excited carbonyl compounds, into which they decompose on thermal or photochemical activation. In the presence of DNA, the decomposition of dioxetanes gives rise to DNA modifications, which have been studied by means of specific repair endonucleases. Cyclobutane pyrimidine dimers, which are generated by triplet-triplet energy transfer, were detected by a UV endonuclease; they made up between 2% and 30% of the total modifications recognized by a crude repair endonuclease preparation from Micrococcus luteus. For various 1,2-dioxetanes, the yield of pyrimidine dimers was proportional to their triplet excitation flux. DNA strand breaks, sites of base loss (AP sites; recognized by exonuclease III and endonuclease IV) and dihydropyrimidines (recognized by endonuclease III) were found to represent only a small fraction of the modifications. The majority of the modifications detected were recognized by formamidopyrimidine-DNA glycosylase (FPG protein) and represent 8-hydroxyguanine (7,8-dihydro-8-oxoguanine) residues or other yet not defined base modifications which are recognized by this enzyme. The modifications were generated in similar relative yields by thermal and photo-induced decomposition of the 1,2-dioxetanes and therefore emanate under both conditions from the excited carbonyl compounds. The formation of the FPG protein-sensitive modifications was efficiently quenched by azide anions; the Stern-Volmer quenching of these modifications was 150-fold more effective than that of the pyrimidine dimers. The relative amounts of the two types of modifications were strongly dependent on the structure of the 1,2-dioxetanes and on the concentration of molecular oxygen. Singlet oxygen appears to be involved only to some extent in the generation of the FPG protein-sensitive base modifications as their yield was only moderately (approximately 2-fold) increased in D2O as solvent. A mechanism is suggested in which oxidized guanine is predominantly formed by a single-electron-transfer reaction of the triplet excited carbonyl product derived from the 1,2-dioxetane, followed by unknown secondary oxidations, which involve molecular oxygen and/or undecomposed 1,2-dioxetane.
BACKGROUND: Various types of brushes are efficient for the removal of foreign material accidentally projected into the skin by explosive or abrasive trauma. OBJECTIVE: To evaluate how different times between injury and treatment influenced esthetic results, we retrospectively evaluated 14 patients subjected to the brushing technique. METHODS: Two groups were identified. Group I had been treated within 24 hours of injury. In group II debridement had been performed later. RESULTS: Cosmetic results were strikingly better in group I. CONCLUSION: Our results demonstrate that debridement of traumatic tattoos should be carried out as soon as possible to achieve favorable cosmetic results.
The clinical features to establish the diagnosis of X-linked Emery-Dreifuss muscular dystrophy (EMD) were recently redefined at the European EMD workshop in Baarn 1991. These criteria were used to select families from the literature and two new families for linkage analysis with the DNA markers F9, DX52, DXS15, F8C and DXS115. Recombinations are observed with the DNA markers F9, DXS52 and DXS15. No recombinations were found with F8C and DXS115. Multipoint linkage analysis indicates with a maximum location score of 73.9 that the EMD locus maps very close to F8C.
The lungs of 12 patients suffering from ARDS treated by ECCO2-R-therapy were examined. The thickness of the interlobular septa, area portions of honeycombing, bleeding and lung parenchyma with diffuse alveolar damage were assessed by semi-automatic image analysis. Medial thickness of the pulmonary arteries with an external radius ranging between 40 microns and 150 microns was assessed planimetrically. The area portion of honeycombing ranged from 0% to 66% (average: 28.8%, standard deviation: 17.0%). The thickness of interlobular septa was increased with values between 74.0 microns and 195.5 microns (average: 140.4 microns, standard deviation: 41.7 microns; normal controls: 72.0 microns +/- 19.5 microns). Parenchymal and vascular changes were closely related: Average medial thickness rose from nearly normal values (4.9%) in cases with low area portions of honeycombing and bleeding to the double (11.1%) of normal values in cases with area portions of honeycombing and bleeding greater than 40%. We conclude that parenchymal changes due to shock and high inspiratory O2 concentration lead to changes of the pulmonary arterial hemodynamics which result in a quickly developing medial hypertrophy.
In acute respiratory failure gas exchange can be supported or even maintained in an "alternative" way to mechanical ventilation using extracorporeal techniques (extracorporeal membrane oxygenation ECMO, extracorporeal CO2-removal ECCO2R), or intravenacaval oxygenators (IVOX). These techniques, which are currently in use in neonatology, pediatrics, and adult intensive care medicine, or techniques at present in clinical evaluation (IVOX), are reviewed with their indications, contraindications, differences, problems, worldwide results, and possible future applications.
This retrospective follow-up studied lung function and reconvalescence in 38 young patients without primary lung disease, who suffered from severe ARDS and survived by means of extracorporeal lung assist (ELA) treatment. Over a period of 3, 6, 9 and 12-20 months dynamic and static lung volumes and the results of X-ray and CT scan of the thorax were studied. Within the third and sixth month the forced vital capacity, FEV1, and arterial blood gases reached the lower range of normal values. Obvious relative emphysema RV/TLC was observed at the time of discharge from hospital and during the first four months. This was found to reverse during the following months. After a period of 12-20 months all patients had an abnormal diffusion capacity (TLCO) but with normal transfer coefficients (TLCO/VA). Even though ARDS did not induce obstructive changes, the diminished diffusion capacity and the slightly reduced expiratory peak flow in 25-75% of FVC (FEF 25-75) indicates slight changes in the small airways. Following up the X-ray and CT results we found extraordinary morphological restitution. Spiroergometry results showed a normal cardiopulmonary pattern for untrained individuals. 36 of the 38 patients were integrated in normal working and social life within 12-20 months.
The testicular ultrastructure of sexually mature Zebu (Bos indicus) bulls from Costa Rica was studied in relation to their classification based on andrological examinations undertaken in the field. Based on the testicular consistency at palpation, each bull was assigned to one of three groups, ranging from normal (Group A) to markedly reduced testicular consistency (Group C). The ultrastructure of the clinically normal testicle (Group A) in the Zebu bull resembled that of Bos taurus. In testicles with a slight to moderate reduction of testicular consistency (Group B) degenerated primary spermatocytes and spermatids were common at all stages of the seminiferous cycle. Abnormalities in the condensation of the chromatin, acrosomal defects, and the presence of degenerated cells and cellular debris were the most common of disturbances found. In testicles from bulls with a marked reduction of testicular consistency (Group C) the seminiferous epithelium of most tubules showed degenerative changes, thereby making it impossible to classify the stage of the cycle. The changes were mainly restricted to spermatocytes and spermatids, whose relative numbers were reduced. The number of cells undergoing meiotic divisions was also greatly reduced. Changes in the spermatids were also found including the appearance of severe acrosomal defects, such as acrosomal pouches, the failure of nuclear elongation and clear defects in chromatin condensation. The present ultrastructural findings in Bos indicus do not differ from the picture of normal testicular structure and of testicular degeneration usually found in Bos taurus bulls.
In the course of an epidemiological survey in four provinces of Veneto (northeastern Italy) 67 spinal muscular atrophy (SMA) cases (types I, II and III) were recorded. The survey spanned the period 1960-1983 and involved 859,891 consecutive live-born infants in a population of 2,635,800 inhabitants. The overall prevalence at birth for SMA types I, II and III was 7.8/100,000 live births. Type I alone accounted for 4.1/100,000 live births. If the hypothesis that SMA types I, II and III are clinical manifestations of allelic mutations is assumed, the mutation rate would be about 70 x 10(-6) and the frequency of the heterozygotes 1 in 57.
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Within the last four years magnetic resonance angiography (MRA) developed very rapidly towards a well accepted screening technique for vascular examinations as a fast add on to conventional MR. This review describes the basic physical principles as well as the different methods like time-of-flight and phase-sensitive MRA for visualization of blood vessels. Different applications of 3D, 2D sequential and 3D multi-volume MRA are shown from various regions of the head and body. A short outlook to quantitative flow measurements is given in the last chapter including some interesting applications of these techniques which show the still expanding potential of magnetic resonance.
A case of parakeratosis in pigs due to secondary zinc deficiency (zinc/calcium ratio 0.4 g/100 g; 68.7 mg zinc, 17.1 g calcium per kg food) is reported. Morbidity and symptoms were much more marked in growing boars than in female animals of the same age. In sows the disorder appeared ten days after the first symptoms were seen in the boars. Adult breeding pigs developed no signs of parakeratosis.
A case report on a 6-year-old boy suffering from the extremely rare Hutchinson-Gilford syndrome (progeria) is presented. The results of histopathological and immunohistological examination of the scar-like skin lesions are reported. Subcutaneous amorphous nodules were eosinophilic, PAS- und elastica-negative und remained unstained with antibodies against collagen type IV, vimentin, and collagenase. The dense perivascular infiltration consisted of CD4+, CD8-, alpha-1-antichymotrypsin-, MAC 387-, and some vimentin-positive cells. Perinodular blood vessels were more abundant and had a thickened wall. Collagen bundles were swollen. The epidermis appeared atrophic with focal basal cell degeneration.
Lentigo maligna denotes flat, pigmented lesions predominantly in areas of actinic damage that have the propensity to become malignant. More than 10 years may pass before lentigo maligna evolves into an invasive neoplasma. As an invasive process, it is termed lentigo maligna melanoma (LMM), and it has the potential for both lymphatic and hematogenic metastases. Because of the size and location of the lesions, cosmetically unsatisfactory scars may result from conventional surgery. Therefore, alternative means of treatment, including cryosurgery, have been employed. We report on 12 patients suffering from lentigo maligna who had been treated successfully by cryosurgery between 1984 and 1990. The average follow-up period was 51.4 months, and the recurrence rate was 8.3 percent. Knowing that microinvasive components can be demonstrated in 15 percent of lentigo maligna lesions, we retrospectively reassessed our patients by immunohistochemical procedures with S-100 protein. Although intradermal microinvasion could be confirmed in one patient, no recurrence had been observed within 61 months of follow-up. Provided that patients are selected properly and extension of cryonecrosis is monitored, cryosurgery may prove an efficient alternative to conventional surgery in the treatment of lentigo maligna.
Oscillatory resistance Rrs and reactance Xrs curves were measured in the frequency range 4-25 Hz at FRC-level and at the course of vital capacity manoeuvres. The 55 subjects investigated were separated into the three groups healthy subjects and patients with restrictive and obstructive lung diseases by means of the parameters airway resistance Raw and lung compliance CL estimated by body-plethysmography and esophageal pressure technique, respectively. In accordance with the Raw- and CL-values in each group the parameters Rrs and Xrs demonstrate at FRC-level a different frequency dependent behaviour. An enhancement of Raw in patients with COLD causes a drop of Rrs(f) and a displacement of the whole Xrs-curve into the negative direction. Conversely, the reduction of CL in patients with fibrosis leads to a significant decrease of Xrs-values at lower frequencies without marked changes in the Rrs-curves. An additional enhancement of Raw and a further reduction of CL can be induced by decrease and increase of lung volume VL in comparison with the FRC-level. These alterations can be detected also in the frequency dependent shape of the Rrs- and Xrs-curves. Because of this inverse influence of VL on Raw and CL the diagnostic differentiation between patients with mild obstructive and restrictive lung diseases can be improved by a simultaneous evaluation of the volume and frequency dependence of oscillatory parameters.