A new method for radiochemical separation of arsenic from irradiated germanium oxide.

Radioarsenic labelled radiopharmaceuticals could be a valuable asset to Positron Emission Tomography (PET). In particular, the long half-lives of (72)As (T(1/2)=26 h) and (74)As (T(1/2)=17.8 d) allow to investigate slow physiological or metabolical processes, like the enrichment and distribution of antibodies in tumor tissue. This work describes the direct production of no-carrier-added (nca) arsenic isotopes *As, with *=71, 72, 73, 74 or 77, the reaction to [*As]AsI(3) and its radiochemical separation from the irradiated solid germanium oxide via polystyrene-based solid-phase extraction. The germanium oxide target, irradiated at a cyclotron or a nuclear reactor, is dissolved in concentrated HF and Ge is separated almost quantitatively (99.97%) as [GeF(6)](2-). [*As]AsI(3) is formed by addition of potassium iodide. The radiochemical separation yield for arsenic is >90%. [*As]AsI(3) is a versatile radioarsenic labelling synthon.

Bone phenotype of the aromatase deficient mouse.

Estrogens are important for normal bone growth and metabolism. The mechanisms are incompletely understood. Thus, we have undertaken characterization of the skeletal phenotype of aromatase (ArKO) deficient mice. No abnormalities have been noted in skeletal patterning in newborns. Adult ArKO mice show decreased femur length and decreased peak Bone Mineral Density (BMD) with accelerated bone loss by 7 months of age in females. Magnetic resonance microscopy (MR) and microCT (microCT) imaging disclosed decreased cancellous connectivity and reduced cancellous bone volume in ArKO females. Bone formation rate (BFR) is increased in ArKO females and decreased in ArKO males. Estradiol therapy reverses these changes. This anabolic effect of estradiol in the male skeleton is supported by 18-F- Positron Emission Tomography (PET) imaging, which clearly demonstrates decreased spinal uptake, but marked increase after estradiol therapy. Serum IGF-1 levels are high in young female ArKO mice but low in young ArKO males. The reduced BMD in ArKO females, despite the presence of elevated serum IGF 1, suggests that other mechanism(s) are operative. There is increased B-cell lymphopoiesis in adult female ArKO bone marrow cells. These results show that ArKO mice show the effects of estrogen deficiency on bone growth, mass, metabolism, microarchitecture and the hematopoietic microenvironment.

SPECT electronic collimation resolution enhancement using chi-square minimization.

An electronic collimation technique is developed which utilizes the chi-square goodness-of-fit measure to filter scattered gammas incident upon a medical imaging detector. In this data mining technique, Compton kinematic expressions are used as the chi-square fitting templates for measured energy-deposition data involving multiple-interaction scatter sequences. Fit optimization is conducted using the Davidon variable metric minimization algorithm to simultaneously determine the best-fit gamma scatter angles and their associated uncertainties, with the uncertainty associated with the first scatter angle corresponding to the angular resolution precision for the source. The methodology requires no knowledge of materials and geometry. This pattern recognition application enhances the ability to select those gammas that will provide the best resolution for input to reconstruction software. Illustrative computational results are presented for a conceptual truncated-ellipsoid polystyrene position-sensitive fibre head-detector Monte Carlo model using a triple Compton scatter gamma sequence assessment for a 99mTc point source. A filtration rate of 94.3% is obtained, resulting in an estimated sensitivity approximately three orders of magnitude greater than a high-resolution mechanically collimated device. The technique improves the nominal single-scatter angular resolution by up to approximately 24 per cent as compared with the conventional analytic electronic collimation measure.

Analytic treatment of resolution precision in electronically collimated SPECT imaging involving multiple-interaction gamma rays.

The widely applied single-interaction analytic expression characterizing the energy resolution component of the angular resolution precision for an electronically collimated point source is extended to include multiple-interaction Compton scatter sequences as well as sequences terminated by photoelectric absorption. The analytic formulation is developed using the statistical variance of the mean for components comprising composite, multivariate resolution precision estimators. It is demonstrated that enhanced resolution precision in the incident interaction scatter angle is attained when use is made of information from multiple interactions. An improvement in the resolution precision of up to approximately 40% is observed for triple Compton scatter. Comparison of the analytic estimates with Monte Carlo/chi-square results shows good agreement.

[Medical observations in feeding rations consisting of food concentrates]. / Meditsinskie nabliudeniia pri pitanii ratsionami, sostavlennymi iz pishchevykh kontsentratov.

Ten therapeutic and surgical patients aged 19-30 received rations composed of food concentrates during 9 days, their state of health was satisfactory during the whole follow-up period. The palatability of the food was highly appreciated by all the patients at the initial period of their feeding with concentrates, and the food was eaten up completely, it was only on day 7-8 that the patients complained of the "monotony" of the dishes proposed to them, especially, of milk foods. The data of the medical follow-up and physiological examination of the patients revealed no functional changes in their body. No allergic reactions were recorded. The patients were discharged from the hospital in due time.

[Hygienic evaluation of a diet consisting of canned products containing milk and vegetable proteins]. / Gigienicheskaia otsenka ratsiona pitaniia, sostoiashchego iz konservirovannykh produktov s vkliucheniem molochnogo i rastitel'nogo belka.

An experiment was carried out on the volunteers who received during 3 weeks dinners composed of canned foods containing milk and vegetable proteins. Canned beef and mutton contained 33% of casein and 8% of soybean protein, 50% of casein and 14% of soybean protein were included into canned pork. During the whole period of the experiment the volunteers felt well and did accept the repeated dishes. The medical and physiological investigations showed no changes in their health and body function. No allergic reactions were recorded.

[Changes in body functional state of man receiving ready-to-use food concentrate bricks]. / Izmenenie funktsional'nogo sostoianiia organizma cheloveka pri pitanii gotovymi k upotrebleniiu pishchevymi briketirovannymi kontsentratami.

During 3 days 8 young volunteers received briquet food concentrates ready for use. The concentrates made up the pocket diet to be employed on an individualized basis. The mass of the diet was 600 g. It included 118.4 g protein, 39.9 g fat, and 370.8 g carbohydrates. The test subjects ate up their food appraising the gustatory qualities of the diet constituents. The loss of the body mass amounted to 0.77 kg during the first day, 0.22 kg during the second, and 0.19 kg during the third day of being kept on the diet. Medical and physiological studies did not reveal any substantial alterations in body function of the test subjects during the entire observation period. No allergic reactions were recorded.

[Body function in nutrition with a diet made up of canned products during acclimatization to a hot climate]. / Funktsional'noe sostoianie organizma pri pitanii ratsionom iz konservirovannykh produktov v period akklimatizatsii k usloviiam zharkogo klimata.

Eight physically trained male volunteers living in tropical countries were examined. Being under high physical load they were given the diet (for 3 weeks) containing food concentrates and canned food with a caloric value of 3860 calories. Energy expenditures amounted to 3600-4100 kcal/day. According to the physiological data the central and peripheral nervous systems and higher nervous activity remained unchanged throughout the entire observation period. As shown by the PWC170 test, the orthostatic stability and exercise tolerance were lowered at the initial period of the living in hot climate. Subjectively this was manifested by excessive fatigue toward the end of the working day. All the characteristics under study returned to normal by the 10th day of living in hot climate. The data obtained indicate that under the conditions of hot climate and appreciable physical loading, it is necessary to take into account the changes in body function in order to improve the diet for the people to be able to get adapted to the conditions in question.

[Changes in various indicators of orthostatic stability in humans on long-term low-caloric diets]. / Izmenenie nekotorykh pokazatelei ortostaticheskoi ustoichivosti u cheloveka pri prodolzhitel'nom pitanii malokaloriinym ratsionom.

Ten male volunteers received a low-caloric diet (LCD) (under 1200 kcal) containing 49.4 g protein, 28 g fat and 181 g carbohydrates for 3 weeks, with energy expenditure amounting to about 2900 kcal/day. During the time indicated, the body mass of the test subjects dropped by 7.1%. According to subjective data the well-being, physical and mental working ability remained unchanged in the test subjects. During feeding with the LCD and making the active orthostatic test, the increment of the heart rate upon the change of the body position appeared the same as that during the comparison period. Meanwhile on the 6th day of the recovery period the increment was significantly higher than at the comparison period. The systolic, pulse and mean arterial pressure, with the test subjects fed the LCD being in the vertical position and at the recovery period, was lower than at the comparison period. The data obtained attest to a definite lowering of the orthostatic stability of man kept on the LCD for a long time and at the recovery period, with this lowering taking place chiefly at the expense of changes in the tone of peripheral blood vessels.

[Human body function indices in the long-term feeding of a low-calorie diet composed of canned products]. / Nekotorye pokazateli funktsional'nogo sostoianiia organizma cheloveka pri prodolzhitel'nom pitanii malokaloriinym ratsionom iz konservirovannykh produktov.

Five healthy trained men aged 27-46 with a body weight approximating an ideal one were kept on a diet containing 95.4 g protein, 552.6 g carbohydrates and 81.3 g fat for 3 days, whereupon they received 1/3 of the indicated diet for 20 days. Energy losses averaged 2913 kcal/day. As a result of receiving the low-caloric diet (LCD), the body weight of the examined dropped from 75.8 to 70 kg. central nervous system function and higher nervous activity remained the same as shown by the reflexometry data, digital and corrections tests; the heart rate was 8-12 beats per minute lower in all the examined throughout all the observation periods both at rest and during exercise as compared to the respective characteristics of the adaptation period. The PWC170 value increased by 12-17% on the average. According to subjective data body function of the examined did not change substantially as a result of being fed the LCD.