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  • 1
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Acute intermittent porphyria (AIP) is an autosomal dominant disorder caused by a partial defect of the heme biosynthesis enzyme, porphobilinogen deaminase (PBGD). PBGD is encoded by two distinct mRNA species expressed in a tissue-specific manner from a single gene. One transcript is expressed in erythroid tissues, while the housekeeping transcript is expressed in all tissues. In classical AIP (95% of cases) the housekeeping and the erythroid-specific enzymes both have half-normal activity in erythroid and non-erythroid tissues, whereas in the variant non-erythroid form of the disease the enzymatic defect is present only in non-erythroid cells. A large allelic heterogeneity of mutations (n〉135) has been demonstrated in classical AIP, but to date only three different mutations have been characterized in the non-erythroid variant form of AIP. We describe the molecular abnormalities responsible for the non-erythroid variant form of AIP in two French and two German unrelated AIP patients with normal PBGD activity in the erythrocytes. Three different splicing defects located in the intron 1 donor splice site were identified: a 33+1 g→a mutation, previously described in a Dutch family, was found in two patients; two novel mutations (33+2 t→a, 33+5 c→g) affected the two remaining patients. All the mutations resulted in the activation of a cryptic splice site 67 bp downstream in intron 1, leading to a frameshift and a premature stop codon in exon 4. Mutations in the exon 1 donor splice site are involved in eight of the nine non-erythroid variant AIP families reported in the literature. These data show that most mutations causing the non-erythroid variant AIP are exon 1 splice defects, in contrast with classical AIP, where missense mutations are chiefly involved. Moreover, the allelic heterogeneity of PBGD gene defects causing the non-erythroid variant AIP is demonstrated, with five different mutations identified. These mutations could be easily detected by a single denaturing gradient gel electrophoresis which also allows the presymptomatic detection of gene carriers in the affected families.
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  • 2
    ISSN: 1600-0501
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: The surface structure, in particular the surface roughness, and the surface chemistry of titanium implants influence their anchoring in bone. The aim of this study was to analyse metal–bone contact (MBC) after modification of the implant surface, using different materials for blasting. The surface modification of titanium was produced by blasting it with particles made of Al2O3 or bioceramics. The biological effects were then investigated experimentally using 27 rabbits, analysed after 7, 28 and 84 days after the implantation of titanium cylinders treated accordingly. The MBC showed a tendency for more bone after bioceramics were used as a blasting material, compared to Al2O3.
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  • 3
    ISSN: 1615-6714
    Keywords: Key Words Pendulum appliance ; Distal screw ; Uprighting activation ; Class-II malocclusion ; Non-compliance therapy ; Molar distalization ; Anchorage loss ; Schlüsselwörter Pendelapparatur ; Distalschraube ; Aufrichteaktivierung ; Klasse-II-Okklusionsanomalie ; Kooperationsunabhängigkeit ; Molarendistalisierung ; Verankerungsverlust
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung: Die heutige Kieferorthopädie verlangt in verstärktem Maße nach Behandlungsabläufen und Geräten, die den Behandler von der Patientenkooperation weitgehend unabhängig machen. Dazu müssen neue Behandlungsgeräte entwickelt, vorhandene durch Modifikationen optimiert werden. Ziel der vorliegenden klinischen Studie war es, die therapeutischen Effekte einer kooperationsunabhängigen modifizierten Pendelapparatur (Distalschraube und integrierte Molarenaufrichteaktivierung) zu analysieren. Die dentoalveolären und skelettalen Wirkungen und Nebenwirkungen wurden an 50 Kindern und Jugendlichen überprüft. Dentoalveolär zeigten sich folgende Ergebnisse: Der klinisch sichtbare Platzgewinn entstand zu 72,5% durch Molarendistalisierung und zu 27,5% durch Mesialisierung des anterioren Segments. Die Molaren wiesen eine geringe Distalkippung und Extrusion auf, die Schneidezähne waren leicht nach labial gekippt. Zeitlich betrachtet wurden die Molaren durchschnittlich 0,67 mm pro Monat distalisiert. Die skelettalen Veränderungen während der Pendelapparaturbehandlung sind erheblich. Weitere Vorteile der Pendelapparatur sind die Unabhängigkeit von der Patientenkooperation sowie die gute Patientenakzeptanz.
    Notes: Abstract: In present-day orthodontics there is an increasing call for therapeutic procedures and appliances allowing those delivering the treatment maximum independence from patient cooperation. This requires both the development of new therapeutic appliances and the optimization of existing ones (via modification). The present study aims to analyze the therapeutic outcomes obtained by using a pendulum appliance (distal screw and integrated molar uprighting activation), modified and independent of patient cooperation. The dentoalveolar and skeletal outcomes and secondary outcomes were observed in 50 children and adolescents. The dentoalveolar outcomes were as follows: 72.5% of the clinically visible increase in space were gained by distal molar movement and 27.5% by mesialization of the anterior segment. The molars showed slight distal tipping and extrusion, while the incisors showed slight labial tipping. In terms of time, the molars were moved distally by an average of 0.67 mm per month. Skeletal changes taking place during treatment using the pendulum appliance are negligible. Further advantages of the pendulum appliance are independence from patient cooperation and good acceptance by patients.
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  • 4
    ISSN: 1615-6714
    Keywords: Key Words: Unilateral molar distalization ; Patient compliance ; Two-tooth concept ; Anchorage system ; Schlüsselwörter: Unilaterale Molarendistalisation ; Patientenkooperation ; Zwei-Zahn-Konzept ; Verankerungsaufbau
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung: Eine asymmetrisch aktivierte Lingualbogenapparatur ermöglicht im Unterkiefer eine rasche unilaterale Molarendistalisation ohne aktive Mitarbeit des Patienten. Im Sinne der segmentierten Bogentechnik reduziert sich entsprechend dem Zwei-Zahn-Konzept die Biomechanik auf den zu bewegenden Zahn und ein großes vielwurzeliges Zahnsegment als Verankerungseinheit. Auf die Einbeziehung des Oberkiefers kann beim Verankerungsaufbau verzichtet werden.
    Notes: Abstract: An asymmetrically activated lingual arch appliance enables rapid, unilateral molar distalization in the mandible without active patient compliance. Using the segmented arch technique, the biomechanics involve only the tooth moved, in accordance with the 2-tooth concept, with a large, multi-rooted tooth segment acting as an anchoring unit. The anchorage system requires no maxillary involvement.
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  • 5
    ISSN: 1591-9528
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Zusammenfassung In der Umgebung umschriebener Hautverletzungen kommt es nicht nur zu der durch freigesetzte histaminartige Substanzen ausgelösten 3fachen Reaktion der HautgefÄ\e mit lokaler Rötung, reflektorischem Hof und Quaddelbildung, sondern infolge Reizung lokaler Nerven auch zu einer ausgedehnten und scharf begrenztenhyperalgetischen Zone, für die nachLewis nicht histaminartige in der Haut freigesetzte Substanzen verantwortlich sein sollen. Unsere vorstehend beschriebenen Untersuchungen zeigen, da\ sich die hyperalgetischen Verletzungszonen der Haut durch 0,5 mg Histamin sc. regelmÄ\igvergröΒern und verstÄrken und durch 50 mg Antihistamin i.m.elektiv verkleinern undabschwÄchen lassen. Melubrin, Novocain und Pendiomid i. v. haben dagegen keine elektive Wirkung auf die Hyperalgesie, sondern verursachen eineallgemeine, Schwellenerhöhung. Daraus wird in übereinstimmung mit neueren Angaben vonGaddum geschlossen, da\ nicht nur dem reflektorischen roten GefÄ\hof, sondern auch der mit diesem zeitlich und örtlich eng gekoppelten VerIetzungshyperalgesie ein durch histaminartige Substanzen wirksamer Nervenmechanismus zugrunde liegt. In diesem Zusammenhang werden die Untersuchungsergebnisse vonLewis undMarvin, Foerster, Ungar, Kwiatkowsoi und U. S. v.Euler erörtert, die ebenfalls dafür sprechen, da\ au\er adrenergischen und cholinergischen Nerven noch eine besondere Gruppehistaminergischer Nerven in der Peripherie unterschieden werden mu\. Diese treten offenbar nur unterpathologischen Bedingungen in Funktion und sind in der Haut „nocifensorisch“, d. h. mit der Abwehr örtlicher SchÄdlichkeiten betraut. Ob diese zum Hinterwurzelsystem gehörenden Nerven entsprechend der Annahme vonLewis einbesonderes System bilden oder ob sie zum Schmerzapparat gehören, ist noch ungeklÄrt. Auf dieklinische Bedeutung dieser Frage wird im Rahmen der vorliegenden Arbeit nur kurz hingewiesen.
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  • 6
    ISSN: 1600-0714
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: An 82-year-old Caucasian man developed an ulcerated mass on the anterior mandibular gingiva. Five years previously he had been treated for a Merkel cell carcinoma (MCC) on his right cheek. Histopathologic examination showed small tumor cells with scanty cytoplasm, suggestive of malignancy. Immunohistochemical studies were performed with the use of nine antibodies. S-100 protein and leukocyte common antigen were helpful in ruling out melanoma and lymphoma. Pronounced reaction was shown for cytokeratin 20. a new histodiagnostic marker whose expression is almost entirely confined to Merkel cells, the gastric epithelium, and urothelium. The tentative diagnosis of metastasis of MCC was confirmed. Immunohistochemical studies are useful diagnostic aids in the establishment of the diagnosis of Merkel cell carcinoma.
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  • 7
    ISSN: 1365-2958
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Medicine
    Notes: The oxidative decarboxylation of coproporphyrinogen III catalysed by an oxygen-dependent oxidase (HemF) and an oxygen-independent dehydrogenase (HemN) is one of the key regulatory points of haem biosynthesis in Pseudomonas aeruginosa. To investigate the oxygen-dependent regulation of hemF and hemN, the corresponding genes were cloned from the P. aeruginosa chromosome. Recognition sequences for the Fnr-type transcriptional regulator Anr were detected −44.5 bp from the 5′ end of the hemF mRNA transcript and at an optimal distance of −41.5 bp with respect to the transcriptional start of hemN. An approximately 10-fold anaerobic induction of hemN gene expression was mediated by the dual action of Anr and a second Fnr-type regulator, Dnr. Regulation by both proteins required the Anr recognition sequence. Surprisingly, aerobic expression of hemN was dependent only on Anr. An anr mutant did not contain detectable amounts of hemN mRNA and accumulated coproporphyrin III both aerobically and anaerobically, indicating the importance of HemN for aerobic and anaerobic haem formation. Mutation of hemN and hemF did not abolish aerobic or anaerobic growth, indicating the existence of an additional HemN-type enzyme, which was termed HemZ. Expression of hemF was induced approximately 20-fold during anaerobic growth and, as was found for hemN, both Anr and Dnr were required for anaerobic induction. Paradoxically, oxygen is necessary for HemF catalysis, suggesting the existence of an additional physiological function for the P. aeruginosa HemF protein.
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  • 8
    ISSN: 1432-1335
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The malignant melanoma of the choroid consists of melanocytes with slight pigmentation and of tumor cells (“macrophage-like”) that are heavily pigmented and perivascularly localized. In 7 malignant melanomas of the choroid belonging to the spindle cell and epithelioid type (Reese), the “macrophage-like” tumor cells histochemically showed a high activity of nonspecific esterases and acid phosphatases; the activity in melanocytes was low. A malignant melanoma of the epithelioid type chiefly contained tumor cells with high enzymatic activity and showed all transitional cells from melanocytes to “macrophages”. Zymograms of all melanomas (electrophoresis of tumor extract on agar-agar) showed similar fractions of isodynamic esterases and acid phosphatases which differed only in activity. The “macrophage-like” cells and the melanocytes were tumor cells. A relation presumably existed between the high activity of phosphatases and the increased incorporation of phosphate (P32) into the tumor cells.
    Notes: Zusammenfassung Melanoblastome der Chorioidea bestehen aus wenig pigmentierten Melanocyten und stark pigmentierten als “Makrophagen” bezeichneten perivasculären Zellen. In sieben histochemisch untersuchten Melanoblastomen der Chorioidea besaßen die “Makrophagen” eine starke Aktivität unspezifischer Esterasen und saurer Phosphatasen, in den Melanocyten war die Aktivität schwach. Ein Melanoblastom vom epitheloiden Typ enthielt vorwiegend Zellen mit starker Enzymaktivität und zeigt außerdem alle Übergänge zwischen Melanocyten und “Makrophagen”. In allen Melanoblastomen waren die Fraktionen der isodynamen Esterasen und sauren Phosphatasen (Zymogramme nach Agarelektrophorese des Tumorextraktes) gleichartig, lediglich die Aktivität der einzelnen Fraktionen ist etwas verschieden. Die als “Makrophagen” bezeichneten Zellen sind ebenso wie die Melanocyten tumoreigene Zellen. Die starke Phosphataseaktivität wird auf den verstärkten Einbau von Phosphat (P32) in die Tumorzellen bezogen.
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  • 9
    ISSN: 1573-5044
    Keywords: Arachis hypogaea ; Photoautotrophic cell cultures ; Rubisco ; PEPCase ; sucrose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Using photoautotrophic cells ofArachis hypogaea (L.) growing at ambient CO2, it was shown that exogenous sucrose supplied to the liquid medium reduced14CO2 fixation (supplied as NaH14CO3). This was mostly due to a reduced labelling in P-esters, and to a lesser extent, in the serine/glycine moiety. However, radioactivity in the neutral sugar fraction was increased upon supplement of exogenous sucrose. The reduced labelling of P-esters and serine/glycine agrees with a lower concentration and specific activity of Rubisco in the sucrose supplied treatments as compared to the control. Following a transfer into a sugar free nutrient medium the concentration and activity of Rubisco is increased. The concentration of PEPCase was not influenced by sucrose application, although its specific activity was increased. At elevated CO2 concentration (2.34% v/v) the Rubisco concentration and specific activity was at the same level as in the control (0.03% v/v CO2). However, the concentration and the specific activity of PEPCase was increased and dry weight increase was about 8–9-fold higher than at ambient CO2.
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  • 10
    ISSN: 1573-5044
    Keywords: Daucus carota ; elevated CO2 concentration ; photoautotrophy ; somatic embryogenesis ; sucrose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In this paper photoautotrophic carrot (Daucus carota L.) suspension cultures are described which are able to produce somatic embryos. The development of somatic embryos, however, requires a sucrose supplement. Although an elevation of the CO2 concentration up to 2.3% results in the same level of dry weight production as with sucrose in the medium, somatic embryos could not be observed. Results on the influence of sucrose on some aspects of the photosynthetic apparatus of cultured cells are discussed.
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