Oppenheim's myatonia congenita

In 1900 the famous German neurologist Hermann Oppenheim published a two-page article on "Myatonia congenita" which led to a long-lasting and confusing discussion in neurology and neuropediatrics, and which was extensively quoted throughout the 20th century. As this article is only available in German, an English translation is presented here. Further publications of Oppenheim on the same subject are mentioned and some comments are made on the impact of his seminal article. It had the merit of drawing the attention to the existence of congenital muscle diseases in children but its impact would be better understood by the influence Oppenheim had on his time, as he was one of the leading neurologists at the end of the 19th and beginning of the 20th century.

Injuries due to letter bombs

In Austria in late 1993 ten letter bombs were sent to outstanding persons who have been engaged in the care of foreigners. Four of these bombs detonated, when they were opened by the addressee. The remaining six bombs were discovered in time and could be deactivated by specialists. The construction of these bombs and the lesions sustained by the four victims will be discussed. The injuries mainly concerned the left hand, i.e., the hand used by right-handed persons to hold a letter when opening it. The way holding the letter was of crucial influence on the degree of injury, as with the same explosive charge (which can be assumed deducing from the investigation of the deactivated bombs) injuries varied considerably. They ranged from minor tissue-lesions to mutilated fingers and the risk of exsanguination.

Terminal differentiation of human liposarcoma cells induced by ligands for peroxisome proliferator-activated receptor gamma and the retinoid X receptor

Induction of terminal differentiation represents a promising therapeutic approach to certain human malignancies. The peroxisome proliferator-activated receptor gamma (PPAR gamma) and the retinoid X receptor alpha (RXR alpha) form a heterodimeric complex that functions as a central regulator of adipocyte differentiation. Natural and synthetic ligands for both receptors have been identified. We demonstrate here that PPAR gamma is expressed at high levels in each of the major histologic types of human liposarcoma. Moreover, primary human liposarcoma cells can be induced to undergo terminal differentiation by treatment with the PPAR gamma ligand pioglitazone, suggesting that the differentiation block in these cells can be overcome by maximal activation of the PPAR pathway. We further demonstrate that RXR-specific ligands are also potent adipogenic agents in cells expressing the PPAR gamma/RXR alpha heterodimer, and that simultaneous treatment of liposarcoma cells with both PPAR gamma- and RXR-specific ligands results in an additive stimulation of differentiation. Liposarcoma cell differentiation is characterized by accumulation of intracellular lipid, induction of adipocyte-specific genes, and withdrawal from the cell cycle. These results suggest that PPAR gamma ligands such as thiazolidinediones and RXR-specific retinoids may be useful therapeutic agents for the treatment of liposarcoma.

c-fos is not essential for v-abl-induced lymphomagenesis

Recent studies have suggested that cellular transformation by abl oncoproteins may be mediated by the ras signaling pathway. One of the main nuclear targets of this signal transduction cascade is the Fos and Jun family of transcription factors. To test the relevance of the c-fos proto-oncogene for v-abl-induced cancer development, we inoculated c-fos-deficient mice with the Abelson murine leukemia virus. Neonatal c-fos-deficient mice infected with the Abelson complex are able to develop the pre-B-cell lymphoma that characterizes Abelson disease. c-fos-deficient animals succumb to the disease with similar kinetics as their wild-type and heterozygous littermates. Moreover, the transformed cell that brings about the malignancy in mutant mice is the same pre-B-cell lymphoblast that is seen in control animals. These results demonstrate that c-fos is not required for in vivo transformation by v-abl.

c-fos is required for malignant progression of skin tumors

The proto-oncogene c-fos is a major nuclear target for signal transduction pathways involved in the regulation of cell growth, differentiation, and transformation. Using the multistep skin carcinogenesis model, we have directly tested the ability of c-fos-deficient mice to develop cancer. Upon treatment with a tumor promoter, c-fos knockout mice carrying a v-H-ras transgene were able to develop benign tumors with similar kinetics and relative incidence as wild-type animals. However, c-fos-deficient papillomas quickly became very dry and hyperkeratinized, taking on an elongated, horny appearance. While wild-type papillomas eventually progressed into malignant tumors, c-fos-deficient tumors failed to undergo malignant conversion. Experiments in which v-H-ras-expressing keratinocytes were grafted onto nude mice suggest that c-fos-deficient cells have an intrinsic defect that hinders tumorigenesis. These results demonstrate that a member of the AP-1 family of transcription factors is required for the development of a malignant tumor.