Depth of alveolar bone dehiscences in relation to gingival recessions

Dehiscence depths were measured in vivo during surgical treatment of 113 teeth with gingival recession in 27 subjects. The average dehiscence depth determined was 5.43 mm with an average recession depth of 2.67 mm. Statistical evidence of a correlation between recession depth and dehiscence depth (average distance between lowest point of recession and dehiscence = 2.8 mm) leaves 16 affected teeth (n = 113) with a distance of 4 mm or more (up to a maximum of 7.5 mm) between the gingival margin and the alveolar crest (facial) unaccounted for. The significance of these deviations from mean values in the etiology and prognosis of recessions is discussed.     

运动试验引起的室上性早搏ST段压低的临床意义

本文通过平板运动试验与放射性核素检查结果相对照，对８６例拟诊冠心病患者在运动试验期间引起的室上性早搏ＳＴ段压低的临床意义进行了研究。认为运动试验期间引起的室上性早搏ＳＴ段压低幅度大于其前窦性心搏ＳＴ段压低的幅度，是心肌缺血的敏感标志。且二者差值的大小与冠脉病变程度呈正相关。此情况亦见于在运动试验中表现为假阴性的冠心病患者，从而增加了运动试验在检测冠心病中的敏感性。     

Der in vitro-Effekt der Hyperthermie auf den Einbau von Nucleinsäurevorläufern in Tumoren und normale Gewebe

Zusammenfassung Die Inkorporation von Präkursoren der Nucleinsäuresynthese wie ³H-Thymidin und ³H-Uridin in Zellen schnell proliferierender Gewebe kann in vitro durch Erhöhung der Temperatur im Inkubationsansatz auf 39,0° C und 41,0° C gehemmt werden. Tumorgewebe, embryonale Gewebe und regenerierende Leber verhalten sich dabei gleichartig. Die Hemmwirkung ist bei allen diesen Geweben proportional sowohl zum Ausmaß als auch zur Dauer der Temperaturerhöhung. Unsere Befunde sprechen außerdem für eine individuelle Wärmesensibilität der untersuchten Tumoren und der anderen rasch proliferierenden Gewebe. Die gleichzeitige Anwendung von Wärme und Bleomycin führt weder beim Jensen Sarkom noch beim Tumor GW-39 zu einem Additionseffekt. Dagegen zeigen Hydroxyharnstoff und Wärme gleichzeitig angewendet eine additive Hemmwirkung auf den ³H-Thymidineinbau in den Tumor GW-39.Da entsprechende Temperatureinflüsse bei ruhenden Geweben nicht nachzuweisen sind, scheint es sich bei der beobachteten Temperaturempfindlichkeit um eine Besonderheit proliferierender Zellsysteme zu handeln. Es ist daher zu klären, ob sie nur unter den Bedingungen des in vitro-Versuches zum Ausdruck kommt oder, ob sie als Indiz einer allgemeinen Thermosensibilität der Nucleinsäurebiosynthese bei schnell proliferierenden Zellverbänden angesehen werden muß.

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In vitro effect of hyperthermia on the incorporation rate of nucleic acid precursors in tumours and normal tissues

Summary The incorporation of precursors of the nucleic acid synthesis, such as ³H-thymidine and ³H-uridine, in cells of rapidly proliferating tissues can be inhibited in vitro by increasing the temperature in the early stages of incubation from 37–39° C and to 41° C. Tumour tissues, embryo tissues and regenerating liver react to this in the same way. The degree of inhibition in all these tissues is proportionate to both the extent and the duration of the increase in temperature. Our findings also speak for an individual sensitivity to heat among the tumours tested and among other rapidly proliferating tissues. The simultaneous application of heat and Bleomycin leads to no additive effect either with Jensen's sarcoma or with tumour GW-39. On the other hand, hydroxyurea and heat applied simultaneously show an additive inhibitory effect on the incorporation of ³H-thymidine in tumour GW-39.As no corresponding influences of temperature are to be proved with non-proliferating tissues, the observed sensitivity to temperature appears to be a peculiarity of proliferating cell systems. The question must therefore be clarified as to whether this sensitivity is expressed only under the conditions of the in vitro experiment or whether it is to be regarded as evidence of a general sensitivity to heat in the nucleic acid biosynthesis of rapidly proliferating groups of cells.

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Mit Unterstützung der Deutschen Forschungsgesellschaft.     

Antigenic relationship between the C4 Inactivating substance produced by KB cell cultures and the first component of human complement (C1)

Summary The antigenic relationship between the C4-inactivating substance produced by KB cell cultures and the first component of human complement was studied. The antigenic identity of the two substances has been demonstrated applying Ouchterlony's double diffusion method and a special haemagglutination-inhibition method developed by the authors. The site of synthesis of human C1 and its subcomponents has been discussed.     

p75NTR independent oligodendrocyte death in cuprizone-induced demyelination in C57BL/6 mice

Feeding C57Bl/6 J mice the copper chelator cuprizone leads to selective apoptosis of mature oligodendrocytes and concomitant demyelination predominantly in the corpus callosum. The process of oligodendrocyte apoptosis in this animal model for multiple sclerosis (MS) involves early microglial activation, but no infiltration of T-lymphocytes. Therefore, this model could mimic early stages of oligodendrocyte degeneration Affected oligodendrocytes express the common neurotrophin receptor, p75(NTR), a 'stress-receptor' which under certain circumstances can induce apoptosis. Only affected oligodendrocytes in MS lesions and MS animal models express this receptor. In order to study the significance of p75(NTR) in the fate of oligodendrocytes, we have exposed wild-type as well as p75(NTR)-knockout mice to a 0.2% (w/w) cuprizone diet and performed a comparative immunohistochemical analysis of the corpus callosum at various time points. Surprisingly, our results show that the absence of p75(NTR) did not alter cuprizone-induced oligodendrocyte death (and subsequent de- or remyelination). Apparently, intracellular apoptosis pathways in adult oligodendrocytes do not require p75(NTR) activated signal transduction in the absence of T-lymphocytes and T-lymphocyte derived cytokines.