Transition metal-substituted cobalt ferrite nanoparticles for biomedical applications

Transition metals of copper, zinc, chromium and nickel were substituted into cobalt ferrite nanoparticles via a sol–gel route using citric acid as a chelating agent. The microstructure and elemental composition were characterized using scanning electron microscopy combined with energy-dispersive X-ray spectroscopy. Phase analysis of transition metal-substituted cobalt ferrite nanoparticles was performed via X-ray diffraction. Surface wettability was measured using the water contact angle technique. The surface roughness of all nanoparticles was measured using profilometry. Moreover, thermogravimetric analysis and differential scanning calorimetry were performed to determine the temperature at which the decomposition and oxidation of the chelating agents took place. Results indicated that the substitution of transition metals influences strongly the microstructure, crystal structure and antibacterial property of the cobalt ferrite nanoparticles.     

The use of response analysis in confrontation naming

Abstract

Recent assessments of naming disorders in aphasic patients have used error classification as a means of analysing patients' erroneous responses in picture naming. This study assesses the usefulness of this methodology when applied to unselected aphasic patients in the early period following onset. It is concluded that naming analysis, as described in this study, is of limited but potentially important clinical value. The data indicate that the naming response pattern is not strongly related to aphasia classification. However, error response analysis as an isolated technique may provide some insight into the functional locus (or loci) of the naming deficit for some patients. Issues of clinical and theoretical interpretation of naming response patterns are discussed.     

Factors associated with improvement in global aphasia

Abstract

This study evaluates the correlation of initial aphasia examination and several neuroradiologic variables with language recovery 1 year after the onset of global aphasia in 13 patients. Initial performance on language tests—particularly, auditory-verbal comprehension—is strongly correlated with outcome, while the neuroradiologic measures are not. While cerebral tissue characteristics may influence linguistic capabilities either acutely or chronically in the global aphasic patient, the initial language assessment appears to be more reliably associated with improvement than are CT indices of lesion characteristics.     

Glycoprotein Ib and glycoprotein IX are fully complexed in the intact platelet membrane

Two new murine monoclonal antibodies, AK 1 and SZ 1, reactive with the human platelet glycoprotein (GP) Ib-IX complex have been produced by the hybridoma technique. Both AK 1 and SZ 1 immunoprecipitated the GP Ib-IX complex from Triton X-100-solubilized, periodate-labeled platelets. With trypsinized, labeled platelets, AK 1, SZ 1, and FMC 25 (epitope on GP IX) immunoprecipitated a membrane-bound proteolytic fragment of the GP Ib-IX complex consisting of GP IX and an congruent to 25,000 mol wt remnant of the alpha-chain of GP lb disulfide-linked to the beta-subunit. Unexpectedly, although AK 1 and SZ 1 immunoprecipitated purified GP Ib-IX complex, neither antibody immunoprecipitated the individual components of this complex, GP Ib or GP IX. When GP Ib and GP IX were recombined, however, AK 1 and SZ 1 again immunoprecipitated the reformed complex, strongly suggesting that both antibodies were recognizing an epitope present only on the intact complex. Cross-blocking studies indicated that AK 1 and SZ 1 recognized a very similar or identical epitope that was proximal to the epitope for FMC 25. Both AK 1 and SZ 1 bound to a similar number of binding sites (congruent to 25,000) on intact platelets as monoclonal antibodies directed against either GP lb or GP IX. The combined data suggests that GP lb and GP IX are fully complexed in the intact platelet membrane.     

Germ-line mutations, DNA damage, and global hypermethylation in mice exposed to particulate air pollution in an urban/industrial location

Particulate air pollution is widespread, yet we have little understanding of the long-term health implications associated with exposure. We investigated DNA damage, mutation, and methylation in gametes of male mice exposed to particulate air pollution in an industrial/urban environment. C57BL/CBA mice were exposed in situ to ambient air near two integrated steel mills and a major highway, alongside control mice breathing high-efficiency air particulate (HEPA) filtered ambient air. PCR analysis of an expanded simple tandem repeat (ESTR) locus revealed a 1.6-fold increase in sperm mutation frequency in mice exposed to ambient air for 10 wks, followed by a 6-wk break, compared with HEPA-filtered air, indicating that mutations were induced in spermatogonial stem cells. DNA collected after 3 or 10 wks of exposure did not exhibit increased mutation frequency. Bulky DNA adducts were below the detection threshold in testes samples, suggesting that DNA reactive chemicals do not reach the germ line and cause ESTR mutation. In contrast, DNA strand breaks were elevated at 3 and 10 wks, possibly resulting from oxidative stress arising from exposure to particles and associated airborne pollutants. Sperm DNA was hypermethylated in mice breathing ambient relative to HEPA-filtered air and this change persisted following removal from the environmental exposure. Increased germ-line DNA mutation frequencies may cause population-level changes in genetic composition and disease. Changes in methylation can have widespread repercussions for chromatin structure, gene expression and genome stability. Potential health effects warrant extensive further investigation.     

Epidemiology of cervical cancer (author's transl)]

There are remarkable differences of incidence and mortality from cervical cancer between countries and even within small countries. In developed industrial countries, incidence is slowly declining. Age distribution (middle--aged women are mostly afflicted) distinguishes cervical cancer from all other common malignant neoplasms. Known risk factors are: low social class, sexual activity early in youth, instable sexual relationships. Cervical cancer behaves like a veneral disease of low infectious power. Cervical cancer develops stepwise out of epithelial dysplasia and carcinoma in situ. The foundations of a cervical cancer control programme are laid: cytodiagnosis as screening method; well defined high risk groups; effective and not dangerous treatment of prephases and early stages of cancer. In the G.D.R. conditions for effective cancer control are good: cancer registration works stable for more than 20 years; it enables evaluation of effectivity. Cytologic screening can be fully integrated into basic gynecologic care. Medical care including prevention is free of fees and available for all women. The ultimate of goal of a cervical cancer control programme is primary prevention by detection and treatment of preneoplastic lesions (dysplasia and carcinoma in situ).     

Relation of local platelet glycoprotein IIb/IIIa independent activation during coronary angioplasty in acute myocardial infarction to recovery of left ventricular function

We assessed glycoprotein (GP) IIb/IIIa independent platelet activation in coronary sinus and peripheral blood from patients who underwent angioplasty for acute myocardial infarction and stable angina. Despite complete blockade of the activated GP IIb/IIIa receptor with abciximab in patients with acute myocardial infarction, unsuppressed local GP IIb/IIIa independent activation was associated with a lack of recovery of left ventricular function.