[Morphological and functional abnormalities in neuromuscular junctions of Drosophila melanogaster induced by the expression of human APP gene].

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the loss of neurocortical and hippocampal synapses that precedes amyloidosis and neurodegeneration and closely correlates with memory impairment. Mutations in the amyloid precursor protein (APP) cause familial AD and result in the increased production of amyloid-beta-protein (Abeta). To gain insights into synaptic effects of APP, we expressed APP, mutant form APP-Swedish and BACE in the motor neurons of fly larvae. We have shown that targeted expression of APP (APP-Swedish) in Drosophila larval motor neurons causes significant morphological and functional changes in neuromuscular junctions (NMJs): a dramatic increase in the number of synaptic buttons and changes in exocytosis as revealed by incorporation of the styryl dye FM4-64. Analysis of the number and distribution of mitochondria showed that motor neurons overexpressing APP (APP-Swedish) had a significant reduction of functional mitochondria in the presynaptic terminal. Significant synaptic abnormalities were observed for APP (APP-Swedish) and human beta-secretase (BACE) resulting in secretion of amyloid beta protein (Abeta). We suggest that APP participates in regulation of synaptic functions and its elevated expression leads to synaptic pathology independently from neurotoxic effects of Abeta.

[The severity of clinical signs of a tuberculous process in first detected patients].

The severity of clinical signs of pulmonary tuberculosis was studied in first detected patients. A hundred and sixty-eight case histories of the patients admitted to a town tuberculosis dispensary in 2004 were analyzed. A total of 87 (51.8%) patients with tuberculosis-suspected complaints visited the health care facility. Active preventive fluorographic studies revealed 81 (48.2%) patients. A hundred and twelve (66.6%) patients were diagnosed as having severe destructive forms of the disease in the phase of decay and dissemination. The clinical signs of a tuberculous process were less significant or absent in actively detected patients. Later detection of patients makes their people contact them longer and increases the probability of development of an active tuberculous process in the latter.

[Dosimetric and radiobiological characteristics of the radiation field from the reaction d(50 MeV)--Be]. / Nekotorye dozimetricheskie i radiobiologicheskie kharakteristiki radiatsionnogo polia iz reaktsii d(50 MéV)--Be.

The rate of the total absorbed dose within a radiation field produced by the reaction of accelerated (up to 50 MeV) deuterons with a thick beryllium target has been determined and the uniformity of the dose field studied. LD50/30 for C57Bl mice has been evaluated in a mixed gamma/neutron field.

[Determination of the contribution of gamma radiation to absorbed dose and the radiobiological effects in the radiation field resulting from the reaction p(50MeV)--Be]. / Opredelenie vklada gamma-izlucheniia v pogloshchennuiu dozu i nekotorye radiobiologicheskie éffekty v radiatsionnom pole, poluchennom iz reaktsii p(50MéV)--Be.

A contribution of gamma-radiation to a total dose absorbed in the radiation field formed during 50 MeV proton bombardment of a beryllium target has been determined. A study was made of the biological effectiveness of action of mixed gamma/neutron-radiation on albino mongrel and inbred (C57 black) female mice.

[Formation of a fast-neutron beam for radiobiological experiments on the U-240 isochronous cyclotron and a study of its dosimetric characteristics]. / Poluchenie puchka bystrykh neitronov dlia radiobiologicheskikh éksperimentov na izokhronnom tsiklotrone U-240 i issledovanie ego dozimetricheskikh kharakteristik.

The paper submits the description of the channel equipped for radiobiological experiments with fast neutrons at the isochronous cyclotron U-240. A study was made of some dosimetric characteristics of a mixed gamma-and-neutron beam.