In vivo evaluation of magnetite nanoparticles for use as a tumor contrast agent in MRI

Magnetite nanoparticles, coated by three different artificial polypeptides, were conjugated to an antibody specific to the carcinoembryonic antigen (CEA). To protect the particles from fast blood elimination, the coats were modified by various sugars, polyethyleneglycol, albumin, and sialoproteins, respectively. The protective effect was determined by using a specific in vitro test and by analyzing the biodistribution of the nanoparticles in nude mice grafted with CEA-tumors. In particular, a prolongation of the blood circulation time has been expected, if a natural modifier is attached to the coated nanoparticles. Although the elimination rate could hardly be decreased by any modifiers, the tumor accumulation is slightly improved by using the specific sialoprotein glycophorin B. The usefulness of nanoparticles as image contrast agents is probably limited by their microdistribution within the tumor tissue. The requirements for a contrast agent to be highly tissue specific are discussed.     

Proliferative potential and apoptosis in rat glioma cell lines after hyperthermia

The proliferative potential of cultured rat glioma cells (C6 and 9L) was evaluated after hyperthermia using immunohistochemical staining with bromodeoxyuridine (BrdU) and Ki-67 monoclonal antibodies. Apoptosis was assessed by in situ end-labeling of deoxyribonucleic acid breaks. Both BrdU and Ki-67 labeling indexes decreased with increasing hyperthermia time. The decrease of the Ki-67 labeling index was not as great as that of the BrdU labeling index. The number of apoptotic cells increased with time after hyperthermia. These results indicate that the antitumor effect of hyperthermia may reflect the induction of apoptosis in the cells within the cell cycle, and the resultant reduction of the proliferative potential of surviving cells, especially in the S phase.     

A 3D-QSAR study on ginkgolides and their analogues with comparative molecular field analysis

Comparative molecular field analysis (CoMFA), a three-dimensional quantitative structure-activity relationship (3D-QSAR) paradigm was used to study the correlation between the physicochemical properties and the in vitro bioactivities of ginkgolide analogues. The correlation derived from CoMFA analysis has a good predictive capability. Based on the result of CoMFA analysis, we designed some compounds. Pharmacological assay indicated that three of these new designed compounds are 2 and 4 times more potent than that of ginkgolides.     

Morphological characterization of small cells resulting from nutrient starvation of a psychrophilic marine vibrio

In a study of 662 sera from a hydatidosis endemic area, the indirect hemagglutination test based on a minimal nonspecificity criterion of positivity and the latex agglutination (LA) test were found to be suitable screening techniques for the detection of sera positive to the arc 5, diagnostic of hydatid infection. The lower nonspecificity of the LA test, its greater simplicity and its excellent correlation with the immunoelectrophoresis test suggest that it is the choice screening technique for use in field surveys or seroepidemiologic studies of hydatid disease. The advantages and limitations of this serologic approach for the detection of human hydatid cyst carriers in field studies are discussed.     

Small-angle X-ray scattering study on the structure and crystallization of amorphous Fe-P-C alloy

The change in structure of an amorphous Fe-P-C alloy during ageing was examined using small-angle X-ray scattering (SAXS) measurement and transmission electron microscopy. The SAXS intensity was related to two different types of scattering regions depending on ageing time and temperature. The major scattering was from the crystalline particles, which had two-phase lamella structures. The average thickness of the lamellae remained constant at about 5 nm during ageing. The interlamella distance was three to five times the lamellar thickness in the regular packing region. Another minor scattering was interpreted as being caused by the local ordering of atomic configuration in the amorphous state. The average size of the scattering region was 1.8 to 2.4 nm and quite similar to the critical range proposed by Giessen and Wagner, beyond which the shortrange order disappears.     

Association of insulin resistance to electrocardiographic changes in non obese Asian Indian subjects with hypertension

Although it is well documented that child maltreatment exerts a deleterious impact on child adaptation, much less is known about the precise etiological pathways that eventuate in child abuse and neglect. This paper reports on a multimethod ecological study of the relationship between neighborhood structural factors and child maltreatment reports in African American and European American census tracts. The study had two major components. First, in an aggregate analysis, the effects of four measures of community structure (impoverishment, child care burden, instability, and geographic isolation) on child maltreatment report rates were examined separately for predominantly African American (n = 94) and predominantly European American (n = 189) census tracts. Impoverishment in particular had a significantly weaker effect on maltreatment rates in African American than in European American neighborhoods. Second, focused ethnographies were conducted in four selected census tracts with child maltreatment report rates in the highest and lowest quartiles. Ethnographic data point to the importance of the social fabric in accounting for differences in child maltreatment report rates by predominant neighborhood ethnicity.