HLA and Down syndrome (DS): parents at the origin of the nondisjunction share no more HLA-A and -B antigens with their DS child than controls

Fifty couples and their children with Down syndrome (D.S.) were typed for HLA-A and HLA-B antigens and compared to 50 control families and 464 blood donors. The parental origin of the extra chromosome 21 was determined by cytogenetic methods. All individuals were caucasians and there was no history of consanguinity. No excessive HLA sharing was present in D.S. parents. The mothers of D.S. shared no more HLA antigens with their D.S. children than the control mothers with their normal children (14% vs. 18%). Thirteen of the fifty pairs (26%) (parent in whom the nondisjunction occurred and D.S. child) shared three HLA antigens at the A and/or B locus. This was not significantly higher than the proportion in the control group (12/50 or 24%). These data suggest that it is not the sharing of HLA-A and HLA-B antigens between the parents or between the parent who was the origin of the nondisjunction and the D.S. child that is related either to the occurrence of trisomy 21 zygotes or to prenatal survival of affected embryos and fetuses.     

Einmal- versus wiederverwendbare Instrumente in der laparoskopischen Cholezystektomie — Kostenkalkulation und Nutzwertbestimmung

Zusammenfassung Grundlagen: Seit Einführung der laparoskopischen Cholezystektomie wird diskutiert, ob bei diesem Eingriff Einmal- oder wiederverwendbare Instrumente eingesetzt werden sollten. Argumenten der Wirtschaftlichkeit wurden Aspekte der Sicherheit und Hygiene entgegengestzt. Eine Beurteilung des Ger?teeinsatzes unter Berücksichtigung der Kosten als auch des Nutzwertes der Instrumente ist bis heute nicht erfolgt. Methodik: Es wurde ein Kostenvergleich von 3 Varianten des Instrumenteneinsatzes durchgeführt (1. wiederverwendbare Instrumente, 2. Einmalger?te, 3. kombinierte Anwendung). Der Wirtschaftlichkeitsrechnung wurde eine Nutzwertbestimmung der einzelnen Instrumente durch die Operateure entgegengestellt. Ergebnisse: Durch den Einsatz von wiederverwendbaren Instrumenten ist eine betr?chtlichen Kostenreduktion (5888 ATS bei ausschlie?licher Anwendung von wiederverwendbaren Ger?ten. 3945 ATS bei kombiniertem Einsatz) zu erreichen. Der Nutzenvergleich zeigte beim Clipsetzer und dem Port für die erste Insertion Vorteile für die Einmalinstrumente. Schlu?folgerungen: Aufgrund der Ergebnisse von Kostenkalkulation und Nutzwertbestimmung stellt der kombinierte Einsatz von wiederverwendbaren und Einmalinstrumenten derzeit die beste Alternative dar.      

Solitary bronchioloalveolar carcinoma: CT criteria

The computed tomographic (CT) scans of 30 patients with solitary bronchioloalveolar carcinoma were reviewed. Common features at CT included the peripheral or subpleural location of a pulmonary mass (25 cases), pseudocavitation (18 cases), heterogeneous attenuation (17 cases), irregular margins forming a star pattern (22 cases), and pleural tags (21 cases). Using these CT criteria, four independent observers attempted to identify cases of bronchioloalveolar carcinoma from a larger sample of lung cancers and benign lesions by categorizing a series of test cases into four probability categories. Although the bronchioloalveolar carcinomas were correctly ranked in the two highest probability categories 75% of the time (in 45 of 60 cases), there was considerable overlap with other lung lesions, particularly with adenocarcinoma and large cell undifferentiated carcinoma. However, even though the typical features of bronchioloalveolar carcinoma are not invariable or highly specific, they are characteristic enough to suggest the diagnosis.     

Diagnostic value of stereotactic biopsy of cerebral lesions in patients with AIDS

Summary A neurological complication occurs in 40–60% of HIV infected patients during the course of the disease. In 10–20% the neurological complication is the first manifestation of the HIV infection. A reliable neuropathological diagnosis is a prerequisite for a specifically selected treatment. While modern computer-assisted imaging techniques, such as computed tomography or magnetic resonance imaging, do possess a high sensitivity, they do not as a rule permit an unambiguous diagnosis.Between October 1989 and July 1994 we biopsied 38 HIV infected patients stereotactically. The indication for the biopsy was determined by having radiologically detectable lesions with no regression tendency in patients under antitoxoplasmosis therapy. In 89% an unambiguous diagnosis wa made based on the biopsy; 11 % of the biopsies were not diagnostic. For the most part, toxoplasmosis (31%) and progressive multifocal leucoencephalopathy (29%) were involved. 18% of the patients suffered from a non-Hodgkin lymphoma. The foci were primarily frontal (47%), parietal (21%) or localised in the basal ganglia area (11%). The result of the biopsy led to a change in treatment for 52% of the patients. Morbidity and mortality of the operation were 0%.The results or our research series are similar to other groups. It was shown that stereotactic brain biopsy is a safe and effective method for establishing a sound basis for treating the frequently life-threatening cerebral complications of AIDS.     

Identification of a gene disrupted by a microdeletion in a patient with X-linked retinitis pigmentosa (XLRP)

The gene for the most frequent from of X-linked retinitis pigmentosa (XLRP), RP3, has been assigned by genetic and physical mapping to a segment of less than 1000 kbp, which is flanked by the marker DXS1110 and the ornithine transcarbamylase (OTC) gene. In search of microdeletions, we have screened the DNA of 30 unrelated patients with XLRP by employing a representative set of YAC-derived DNA fragments that were generated by restriction enzyme digestion and PCR amplification. In one of these patients, a 6.4 kbp microdeletion was detected which was not present in the DNA of 444 male controls. A cosmid contig spanning the deletion was constructed and used to isolate cDNAs from retina-specific libraries. Exons corresponding to these expressed sequences as well as other putative exons were identified by sequencing more than 30 kbp of the critical region. So far, no point mutations in these putative exon sequences have been identified.      

Positional cloning of the gene for X-linked retinitis pigmentosa 3: homology with the guanine-nucleotide-exchange factor RCC1

The gene for retinitis pigmentosa 3 (RP3), the most frequent form of X- linked RP (XLRP), has been mapped previously to a chromosome interval of less than 1000 kbp between the DXS1110 marker and the OTC locus at Xp21.1-p11.4. Employing a novel technique, YAC Representation Hybridization (YRH)', we have recently identified a small XLRP associated microdeletion in this interval, as well as several putative exons including the 3' end of a gene that was truncated by the deletion. cDNA library screening and sequencing of a cosmid centromeric to the deletion has now enabled us to identify numerous additional exons and to detect several point mutations in patients with XLRP. The predicted gene product shows homology to RCC1, the guanine-nucleotide- exchange factor (GEF) of the Ras-like GTPase Ran. Our findings suggest that we have cloned the long-sought RP3 gene, and that it may encode the GEF of a retina-specific GTP-binding protein.      

Sieben Punkte für sieben Minuten – Sieben-Punkte-Checkliste für ein medizinisches Briefing in der Luftrettung (7-4-7-Checkliste)

Notfall + Rettungsmedizin - Anfang September 2019 wurde ein neuer Dual-use-RTH/ITH-Standort in der Westpfalz etabliert. Während der Einarbeitung der medizinischen Crew entstand bei den Autoren...     

Comprehensive mutational scanning of the p53 coding region by two- dimensional gene scanning

A comprehensive mutational scanning test for the p53 coding region based on multiplex PCR and two-dimensional DNA electrophoresis was designed and evaluated. In a 2-step multiplex PCR, the p53 coding region (exons 2-11) was amplified as a single 8646-bp fragment by long- distance PCR in step one. This fragment served as a template for the subsequent co-amplification of the individual exons in two multiplex groups in step two. The multiplex products were then separated, first on the basis of size in non-denaturant polyacrylamide gels and then on the basis of sequence by denaturing gradient gel electrophoresis (DGGE). Primers for optimal PCR, melting behavior and 2-D gel distribution were designed using a recently developed computer program. The resulting two-dimensional gene scanning (TDGS) test was evaluated by screening, in a blinded fashion, 29 coded DNA samples from Li- Fraumeni syndrome patients with previously identified germline mutations. All mutations were correctly detected. This assay provides an accurate, cost-effective and non-radioactive method for simultaneous mutational scanning of all p53 coding exons.