Anisotropic molecular motion on cell surfaces.

Photobleaching in a two-dimensional periodic pattern has been used to characterize the motion of succinylconcanavalin A receptors on the surfaces of mouse fibroblasts. These receptors were found to exhibit anisotropic two-dimensional diffusion in adherent cells having parallel stress fibers. Diffusion coefficients of the order of 10(-11) cm2/sec and 10(-12) cm2/sec were measured for diffusive motions parallel and perpendicular to these fibers. The determination of the anisotropic motion used a two-dimensional Fourier analysis. A study was made of the effect of changes in cell shape on the photobleach pattern.     

The value of plasmid studies in the epidemiology of infections due to drug-resistant Salmonella wien.

Since 1969 strains of Salmonella wien that are resistant to multiple antibacterial drugs have caused widespread epidemics of enteritis in Europe and North Africa. Of 113 British strains examined between January 1970 and January 1977, 67 were multi-resistant. These strains and 22 strains from six other countries were examined to determine their plasmid content. Two plasmids were found in the vast majority of strains: an FIme factor, conferring resistance to ampicillin, chloramphenicol, kanamycin, streptomycin, spectinomycin, sulfonamides, and tetracyclines (ACKSSpSuT), and a nonautotransferring plasmid of resistance type ASSu. The FIme plasmids have dual incompatibility: they are incompatible with group FI factors and with the MP10 plasmid of Salmonella typhimurium, which belongs to a separate group. Other plasmids found in S. wien included principally a ColIa factor and an autotransferring plasmid that codes for ampicillin resistance and belongs to compatibility group I2. The similarity in plasmid content of strains isolated in widely separated areas suggests that they have a clonal origin.     

Changing the model of radiography practice in the UAE: A snapshot of a profession in transition

IntroductionThis study forms part of a needs assessment in relation to the challenges United Arab Emirates (UAE) radiographers face as they move beyond the role of a technician, and their learning needs to facilitate role advancement. It presents a snapshot of the workforce in terms of qualifications, clinical experience, and responsibilities, as it transitions towards an Emirati, led profession. The results will aid the radiography workforce to embrace a broader role within medical imaging and radiographic practice in the UAE.MethodsAn electronically distributed cross-sectional study was conducted among radiographers in the UAE. The questionnaire captured radiographer demographics, qualifications, professional experience, postgraduate training, professional development plans, and their interest in future role developments.Results272 radiographers were invited to participate with a response rate of 68% (n = 185). Thirty-four (18%) radiographers were UAE nationals with the remainder educated overseas. BSc qualifications were held by 153 (82.7%) and had 6–20 years of experience. There were 12 masters’ qualified and two with doctoral qualifications. Modality vendors were significant providers of professional development. Improved job satisfaction and the development of an Emirati led radiography profession were identified as the main gains for role advancement by 171 (92.4%) respondents.ConclusionCurrently, UAE radiographers work within traditional professional boundaries focussing on image acquisition under direct radiologist supervision. At the same time, many respondents revealed they had embraced advanced practice roles after appropriate education and training.Implications for practiceThe findings suggest an Emirati led profession requires the creation of a distinct professional body to represent the interests of radiographers, more investment in postgraduate education, and the creation of a career structure that encompasses positive role development.     

Interferon gamma release assay in the diagnosis of tuberculous mastitis

Tuberculous mastitis is rare, especially in Western countries. We describe a case where the interferon gamma release assay blood test led to diagnosis and successful treatment of the disease.     

Regulation of erythropoietin production in a human hepatoblastoma cell line

Production of immuno and biologically active erythropoietin was documented to occur in the human hepatoblastoma cell line HepG-2. The expression of the erythropoietin gene was further verified by Northern blot analysis using a single stranded RNA probe. In vitro studies showed that erythropoietin production by these cells was not stimulated by hypoxia or cobalt chloride, but was related to the proliferative activity of the cells in culture. In addition it was found that the secretion of erythropoietin was almost completely abrogated by tunicamycin, an inhibitor of N-linked glycosylation. This effect of tunicamycin was also observed in a permanently transfected cell line that secretes erythropoietin in large quantities.     

Effectiveness of methyl-GAG (methylglyoxal-bis[guanylhydrazone]) in patients with advanced malignant lymphoma

We treated 51 patients with advanced malignant lymphoma refractory to conventional therapy with methyl-glyoxal-bis(guanylhydrazone) (methyl- GAG) at doses ranging from 400 to 800 mg/sq m. Therapy was started on a weekly schedule and was switched to every other week in responding patients at the onset of toxicity. Partial responses were observed in 6 of 13 evaluable patients with Hodgkin's disease (46%), 5 of 10 patients with diffuse poorly differentiated lymphocytic lymphoma (50%), 2 of 4 patients with nodular poorly differentiated lymphocytic lymphoma (50%), and 3 of 13 patients with diffuse histiocytic lymphoma (23%). Two of six patients with mycosis fungoides showed objective improvement in cutaneous disease. Toxicity was generally mild and included muscular weakness, myalgia, mucositis, and diarrhea; two patients developed bronchospasm following drug infusions. We conclude that methyl-GAG has major antitumor activity when administered on this schedule to patients with advanced malignant lymphoma. The low degree of toxicity, unique mechanism of action, and minimal myelosuppressive effects suggest that methyl-GAG will prove useful in future trials of combination chemotherapy regimens for the treatment of lymphoma.     

Development of large numbers of mast cells at sites of idiopathic chronic dermatitis in genetically mast cell-deficient WBB6F1-W/Wv mice

The normal skin and other tissues of adult mast cell-deficient WBB6F1- W/Wv or WCB6F1-Sl/Sld mice contain less than 1.0% the number of mast cells present in the corresponding tissues of the congenic normal (+/+) mice. As a result, genetically mast cell-deficient WBB6F1-W/Wv or WCB6F1-Sl/Sld mice are widely used for studies of mast cell differentiation and function. We found that mast cells developed at sites of idiopathic chronic dermatitis in WBB6F1-W/Wv mice and that the number of mast cells present in the skin of WBB6F1-W/Wv mice was proportional to the severity of the dermatitis (in ear skin, there were 33 +/- 4 mast cells/mm2 of dermis at sites of severe dermatitis v 9 +/- 3 at sites of mild dermatitis, 0.8 +/- 0.3 in skin without dermatitis, and 100 +/- 7 in the normal skin of congenic WBB6F1-+/+ mice; in back skin, the corresponding values were 2.0 +/- 0.6, 1.1 +/- 0.9, 0.025 +/- 0.025, and 26.2 +/- 3.2). The development of mast cells was a local, not systemic, consequence of the dermatitis. Thus, WBB6F1-W/Wv mice with severe dermatitis lacked mast cells in skin not showing signs of dermatitis and also in the peritoneal cavity, stomach, cecum, and tongue. Idiopathic chronic dermatitis was not associated with the local development of mast cells in WCB6F1-Sl/Sld mice, a mutant whose mast cell deficiency is due to a mechanism distinct from that of WBB6F1-W/Wv mice. These findings may have implications for understanding the nature of the mast cell deficiency in WBB6F1-W/Wv and WCB6F1-Sl/Sld mice and for the use of these mutants to analyze mast cell differentiation and function.