Dithiane- and trithiane-based photolabile scaffolds for molecular recognition.

[see structure]. A modular synthetic approach to novel dithiane- and trithiane-based photolabile molecular hosts equipped with elements of molecular recognition is developed. The approach provides ready access to a family of amino-derivatized photocleavable molecular systems capable of hydrogen-bonding-based recognition of biologically relevant molecules, e.g., ureas, barbiturates etc. These systems undergo efficient photofragmentation in the presence of external (e.g., benzophenone) or internal (e.g., nitropyridine) electron-transfer sensitizers.

Molecular assembly and disassembly: novel photolabile molecular hosts

A new approach to the assembly and photochemical disassembly of molecular hosts is developed. It is based on photoinduced fragmentation in hydroxyalkyl dithianes and utilizes a novel spiro-bis-dithiane as a photolabile molecular tether to link two formylated macromolecular blocks, e.g., formyl calixarenes or formyl dibenzocrown ethers. A key feature of this molecular system is that after an assembly-disassembly cycle the starting macromolecular blocks are recovered intact and can be used again.

[T lymphoma of immature phenotype associated with polycythemia vera]. / Linfoma T de fenotipo inmaduro asociado a una policitemia vera.

A 20-year old patient is presented with generalized lymphadenopathy, splenomegaly, hyperleukocytosis and a bone marrow biopsy showing panmyelosis with predominance of immature granulocytes. Lymph node biopsy showed a histopathological feature that was diagnosed as a chronic granulocytic leukemia in blast crisis. The cell surface phenotype of these blast cells showed predominance of immature CD1+, CD7+ T lymphocytes. The T cell lineage was confirmed by DNA rearrangement studies. In addition, the patient showed erythrocytosis, arterial O2 saturation of 92% and thrombocytosis, characteristics of polycythemia vera. After chemotherapy, the patient relapsed with similar symptoms and lymph node cells of similar immature T phenotype. With a revised diagnosis of immature T cell lymphoma associated to a myeloproliferative disorder and polyglobulia, the patient received a combined treatment of Cyclophosphamide-Adriamycin-Vincristine-VM26-Prednisone. Two months later, the patient relapsed again. He received the first phase of induction of the BFM protocol, with partial clinical remission. Five months later, the patient returned with fever, polyadenopathy and splenomegaly. Lymph node cells showed again immature T cell phenotype. The patient was next treated with the m-BACOD scheme, with no response and progression of the disease and he died few days later due to massive bleeding and cardiorespiratory failure.

Linfoma T de fenotipo inmaduro asociado a una policitemia vera / T lymphoma of immature phenotype associated with polycythenia vera

Se presenta un paciente de 20 años con poliadenopatías, esplenomegalia hiperleucocitosis y una biopsia de médula ósea que mostró una panmielosis con predominio d eelementos inmaduros. El estudio histopatológico de la biopsia de un ganglio linfático sugirió el diagnóstico de leucemia mieloide crónica en crisis blástica. El fenotipo inmunológico de las células blásticas mostró predominio de celulas T con fenotipo inmaduro CS1+, CD7+. El linaje celular T se confirmó por estudios de reordenamiento genético. Presenta además eritrocitosis, saturación arterial de O2 de 92% y trombocitosis, características de policitemia vera. Luego de quimioterapia Vincristina y Prednisona, recae a los dos meses con síntomas similares y con células de ganglio linfático del mismo fenotipo T inmaduro. Se replantea el diagnóstico como linfoma T asociado a un síndrome mieloproliferativo y policitemia, y se lo trata con Ciclofosfamida-Vincristina-VM26-Prednisona. Luego de una segunda recaída, dos meses después, se le indica un protocolo BFM, al que responde parcialmente. Cinco meses después el paciente presenta una tercera recaída, donde las células de ganglio muestran nuevamente fenotipo T inmaduro. No responde a un tratamiento con esquema m-BACOD, la enfermedad progresa, falleciendo luego de una hemorragia masiva por un paro cardiorespiratorio (AU)

Linfoma T de fenotipo inmaduro asociado a una policitemia vera / T lymphoma of immature phenotype associated with polycythenia vera

Se presenta un paciente de 20 años con poliadenopatías, esplenomegalia hiperleucocitosis y una biopsia de médula ósea que mostró una panmielosis con predominio d eelementos inmaduros. El estudio histopatológico de la biopsia de un ganglio linfático sugirió el diagnóstico de leucemia mieloide crónica en crisis blástica. El fenotipo inmunológico de las células blásticas mostró predominio de celulas T con fenotipo inmaduro CS1+, CD7+. El linaje celular T se confirmó por estudios de reordenamiento genético. Presenta además eritrocitosis, saturación arterial de O2 de 92% y trombocitosis, características de policitemia vera. Luego de quimioterapia Vincristina y Prednisona, recae a los dos meses con síntomas similares y con células de ganglio linfático del mismo fenotipo T inmaduro. Se replantea el diagnóstico como linfoma T asociado a un síndrome mieloproliferativo y policitemia, y se lo trata con Ciclofosfamida-Vincristina-VM26-Prednisona. Luego de una segunda recaída, dos meses después, se le indica un protocolo BFM, al que responde parcialmente. Cinco meses después el paciente presenta una tercera recaída, donde las células de ganglio muestran nuevamente fenotipo T inmaduro. No responde a un tratamiento con esquema m-BACOD, la enfermedad progresa, falleciendo luego de una hemorragia masiva por un paro cardiorespiratorio

Linfoma T de fenotipo inmaduro asociado a una policitemia vera. / [T lymphoma of immature phenotype associated with polycythemia vera]

A 20-year old patient is presented with generalized lymphadenopathy, splenomegaly, hyperleukocytosis and a bone marrow biopsy showing panmyelosis with predominance of immature granulocytes. Lymph node biopsy showed a histopathological feature that was diagnosed as a chronic granulocytic leukemia in blast crisis. The cell surface phenotype of these blast cells showed predominance of immature CD1+, CD7+ T lymphocytes. The T cell lineage was confirmed by DNA rearrangement studies. In addition, the patient showed erythrocytosis, arterial O2 saturation of 92

and thrombocytosis, characteristics of polycythemia vera. After chemotherapy, the patient relapsed with similar symptoms and lymph node cells of similar immature T phenotype. With a revised diagnosis of immature T cell lymphoma associated to a myeloproliferative disorder and polyglobulia, the patient received a combined treatment of Cyclophosphamide-Adriamycin-Vincristine-VM26-Prednisone. Two months later, the patient relapsed again. He received the first phase of induction of the BFM protocol, with partial clinical remission. Five months later, the patient returned with fever, polyadenopathy and splenomegaly. Lymph node cells showed again immature T cell phenotype. The patient was next treated with the m-BACOD scheme, with no response and progression of the disease and he died few days later due to massive bleeding and cardiorespiratory failure.