Tailoring of the Properties of Amorphous Mesoporous Titanosilicates Active in Acetone Condensation.

Amorphous mesoporous materials are promising as catalysts for processes involving or forming bulk molecules. In a reaction such as acetone condensation to form mesitylene, an effective catalyst should not only have a developed porous structure but also have active centers of acidic and basic types. The sol-gel approach allows one to obtain titanosilicates with such characteristics.

[Undifferentiated pancreatic carcinoma with osteoclast-like giant cells].

In the structure of malignant oncological diseases of the Russian population, pancreatic cancer (PCa) occupies the 10th place with a high mortality rate in case of late diagnosis, which is primarily due to the minimal clinical manifestations of this pathology and the absence of precancer as a potential substrate for screening. Undifferentiated pancreatic carcinoma with osteoclast-like giant cell (UC-OGC) is a rare histological variant of PCa with discussed bidirectional histogenesis (epithelial and mesenchymal), epithelial-mesenchymal transition in the tumor and variable prognosis depending on the predominant cellular component. A review of the literature reflecting debatable issues of origin, clinical and pathological characteristics and prognosis of UC-OGC, as well as a description of a clinical case is relevant due to the rare occurrence of this tumor in the routine work of pathologists and oncologists.

[THE INFLUENCE OF SHORT-TIME CEREBRAL ISCHEMIA ON PIAL VESSELS ADRENOREACTIVITY IN RATS].

Reactivity of pial vessels in response to a brain surface irrigation by norepinephrine solution in rats, subjected to transient global cerebral ischemia (2VO+hypo model), was investigated. Four different groups of rats at 2, 7, 14 or 21 days after ischemia were subjected to microvascular studies using in vivo video microscopy method. The diameter changes of pial arteries and veins in response to norepinephrine were measured.

Changes in Cerebral Blood Flow in the Postischemic Period.

Experiments on Wistar rats showed that blood flow in the cortex and subcortical brain structures was not completely restored within 21 days after transient ischemia caused by bilateral carotid artery occlusion with controlled hypotension. After 7 days of reinfusion, the end-diastolic blood flow velocity increases with simultaneous decrease in pulsation index, which indicates the decrease in peripheral vascular resistance. During the following 14 days, peripheral blood resistance increases, as was seen from the increased peak systolic blood flow velocity, mean blood flow velocity over the heart cycle, and pulsation index.

Postischemic Responsiveness of Pial Vessels to Hypercapnia.

Reactions of pial vessels to hypercapnia were studied in Wistar rats one week after global cerebral ischemia. In ischemic rats, the responsiveness of pial vessels to hypercapnia was diminished, which promoted a decrease in cerebral perfusion reserve. Changes in vascular responsiveness in the arterial and venous subdivisions of the vascular bed were observed and probably resulted from ischemia-provoked down-regulation of the vascular tone.