Energy-dispersive x-ray fluorescence spectroscopy and inductively coupled plasma emission spectrometry evaluated for multielement analysis in complex biological matrices.

Energy-dispersive x-ray spectroscopy and inductively coupled plasma emission spectrometry were evaluated as methods for routine multielement analysis of biological material. Standard samples included Standard Reference Materials (National Bureau of Standards), compounded mixtures, and supplements that provided a wide range of elemental concentrations for analysis. Elements included in this study were Zn, Pb, Ni, Mn, Fe, Mg, Cu, Ca, As, Se, Br, Rb, and Sr. Standards were analyzed as unknowns by participating laboratories. The two methods were evaluated for sensitivity, precision, and accuracy, and the results compared to those obtained for atomic absorption spectrometric analysis of identical standard unknowns. Both methods compared favorably and both were determined to be highly reliable for such an application. Advantages and disadvantages of each method are compared and discussed.     

Occult malignant breast lesions in 114 patients: relationship to age and the presence of microcalcifications

This study evaluates the mammographic findings in 352 patients, aged 30-85 years, who underwent spot localization and biopsy for evaluation of nonpalpable breast abnormalities. Malignancy was found at biopsy in 114 cases. The mammographic appearance (specifically, whether grouped microcalcifications, mass, or both were present) was correlated with patient age and histologic findings (specifically, whether the pathologic changes were infiltrating or noninfiltrating in nature). The prevalence of malignant conditions increased directly with age. The presence of grouped microcalcifications as the sole indicator of malignancy was seen in 100% (seven of seven) of the patients in the 30-39-year age group, 64% (18 of 28) in the 40-49-year age group, 37% (11 of 30) in the 50-59-year age group, 30% (seven of 23) in the 60-69-year age group, and 23% (six of 26) in the 70-85-year age group. Of the 49 tumors that were manifested solely as microcalcifications, 34 (69%) were noninfiltrating. The finding of grouped microcalcifications should be aggressively investigated, since it may indicate noninfiltrating carcinoma in an early stage, when the potential for cure is greatest.     

用自旋捕捉技术检测争光霉素A_6产生的活泼自由基

本文用自旋捕捉技术与ESR相结合的方法,研究了争光霉素A_6-Fe~(2+)复合物产生的活泼自由基。结果发现用NOS自旋捕捉剂可检测到该体系所产生的超氧阴离子自由基。在水溶剂中用PBN自旋捕捉到了羟基自由基。根据PBN-OH自旋加合物在水溶剂和甲醇溶剂中的超精细分裂常数,进一步确证了羟基自由基的生成。     

Standardization and calibration of whole-body autoradiography for routine semiquantitative analysis of the distribution of 14C-labeled compounds in animal tissues

A procedure is described and evaluated for the standardization and densitometric calibration of whole-body autoradiography (WBAR) using ¹⁴C-labeled compounds. Calibration was achieved using uniform ¹⁴C-labeled poly(methyl)methacrylate standards. The mathematical relationship between activity and autoradiographic image density was linear, resulting in a convenient method for the comparison of relative radioactivity in tissues. Temperature and duration of autoradiographic exposure effected the slope but not the linearity of this relationship. The range of linearity of this function allows for a comparison of radioactivity over two orders of magnitude. The effects of section thickness on autoradiographic density were evaluated and determined to be linear over a range of from 10 to 100 μm. It was concluded that this procedure provides a reliable and reproducible semiquantitative method for the routine evaluation of compound or metabolite distribution and can be a valuable adjunct to pharmacokinetic studies.     

Alcohol use disorders: a clinical update

Alcohol use disorders are a significant public health problem. All providers who work with teenagers are likely to encounter youth for whom this is a relevant concern. Routine screening for alcohol use disorders has become the standard of care, and a number of validated, concise screening measures are now available. Youth with alcohol use disorders are unlikely to show the physical stigmata of adult alcohol dependence. Knowledge of risk variables can inform anticipatory guidance and interventions, and all providers can play a helpful role to address problematic use of alcohol.     

Rabbit nasopharyngeal colonization by Bordetella pertussis: the effects of immunization on clearance and on serum and nasal antibody levels

Two Bordetella pertussis antigen preparations, outer membrane protein (OMP) and filamentous haemagglutinin (FHA), and a standard vaccine were used to immunize rabbits, and the effects on nasopharyngeal colonization by the organism were determined. Antibodies were measured in serum and in nasal washes by ELISA before and after challenge of the rabbits with 10(6) bacteria of strain M2. Recoveries of B. pertussis in nasal washes were used to assess colonization, which in controls persisted for at least 65 days. Some rabbits of all the immunized groups showed enhanced clearance, but there was no correlation between the elimination of B. pertussis and serum antibodies to OMP, FHA, lipopolysaccharide, lymphocytosis-promoting factor or agglutinogen 3. In contrast, nasal IgA antibody to FHA showed significant inverse correlation with bacterial persistence. Such antibody was induced by the OMP preparation as well as by FHA, but to different extents depending on the immunization schedule and adjuvant used.     

Subcutaneous mastectomy in the treatment of breast disease

Subcutaneous mastectomy should be performed only for certain well-outlined indications. Preoperative discussion should emphasize that the procedure is not prophylactic for breast cancer, that significant complications are a possibility, and that conclusive data as to diminution of risk are not yet available. Resection of breast tissue including the tail of the breast, should be carefully carried out, deliberately leaving only a small remnant under the areola for preservation of blood supply. Implants should be placed submuscularly leaving all residual breast tissue readily palpable to the examining finger. Continued follow-up procedures and self-examination are to be stressed.