BRCA1 mutations in women attending clinics that evaluate the risk of breast cancer

BACKGROUND: To define the incidence of BRCA1 mutations among patients seen in clinics that evaluate the risk of breast cancer, we analyzed DNA samples from women seen in this setting and constructed probability tables to provide estimates of the likelihood of finding a BRCA1 mutation in individual families. METHODS: Clinical information, family histories, and blood for DNA analysis were obtained from 263 women with breast cancer. Conformation-sensitive gel electrophoresis and DNA sequencing were used to identify BRCA1 mutations. RESULTS: BRCA1 mutations were identified in 16 percent of women with a family history of breast cancer. Only 7 percent of women from families with a history of breast cancer but not ovarian cancer had BRCA1 mutations. The rates were higher among women from families with a history of both breast and ovarian cancer. Among family members, an average age of less than 55 years at the diagnosis of breast cancer, the presence of ovarian cancer, the presence of breast and ovarian cancer in the same woman, and Ashkenazi Jewish ancestry were all associated with an increased risk of detecting a BRCA1 mutation. No association was found between the presence of bilateral breast cancer or the number of breast cancers in a family and the detection of a BRCA1 mutation, or between the position of the mutation in the BRCA1 gene and the presence of ovarian cancer in a family. CONCLUSIONS: Among women with breast cancer and a family history of the disease, the percentage with BRCA1 coding-region mutations is less than the 45 percent predicted by genetic-linkage analysis. These results suggest that even in a referral clinic specializing in screening women from high-risk families, the majority of tests for BRCA1 mutations will be negative and therefore uninformative.     

Antimutagenic activity of casein against MNNG in the E. coli DNA repair host-mediated assay

The effect of caseinate and soy protein in the diet on the mutagenicity induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was assessed in-vivo and ex-vivo in the DNA-repair host-mediated assay and liquid suspension assay, respectively. Of the two proteins only casein showed a strong antimutagenic activity over the whole digestive tract, except in the stomach. It is suggested that the molecular structure of a protein determines its protective effect against mutagens: casein lacks secondary and tertiary structure so that amino acids are more readily available for interaction with the mutagen than with the amino acids in soy protein which is a globular protein.     

Ultrastructural analysis of primary human urethral epithelial cell cultures infected with Neisseria gonorrhoeae

In men with gonococcal urethritis, the urethral epithelial cell is a site of infection. To study the pathogenesis of gonorrhea in this cell type, we have developed a method to culture primary human urethral epithelial cells obtained at the time of urologic surgery. Fluorescent analysis demonstrated that 100% of the cells stained for keratin. Microscopic analyses indicated that these epithelial cells arrayed in a pattern similar to that seen in urethral epithelium. Using immunoelectron and confocal microscopy, we compared the infection process seen in primary cells with events occurring during natural infection of the same cell type in men with gonococcal urethritis. Immunoelectron microscopy studies of cells infected with Neisseria gonorrhoeae 1291 Opa+ P+ showed adherence of organisms to the epithelial cell membrane, pedestal formation with evidence of intimate association between the gonococcal and the epithelial cell membranes, and intracellular gonococci present in vacuoles. Confocal studies of primary urethral epithelial cells showed actin polymerization upon infection. Polyclonal antibodies to the asialoglycoprotein receptor (ASGP-R) demonstrated the presence of this receptor on infected cells in the primary urethral cell culture. In situ hybridization using a fluorescent-labeled probe specific to the ASGP-R mRNA demonstrated this message in uninfected and infected cells. These features were identical to those seen in urethral epithelial cells in exudates from males with gonorrhea. Infection of primary urethral cells in culture mimics events seen in natural infection and will allow detailed molecular analysis of gonococcal pathogenesis in a human epithelial cell which is commonly infected.     

Metaplastic carcinoma of the breast: mammographic appearance with pathologic correlation

OBJECTIVE: The objective of this study was to describe the mammographic appearance with pathologic correlation of metaplastic carcinoma of the breast. CONCLUSION: Metaplastic carcinomas of the breast are masses with mammographic characteristics of low suspicion because of their histologic appearance. Metaplastic carcinoma should be included in the differential assessment of predominately circumscribed, noncalcified masses revealed on mammography. One salient feature that may distinguish metaplastic carcinomas is the occurrence of a circumscribed portion with a spiculated portion, which is seen in carcinomas that have a significant mixture of metaplastic and invasive carcinoma growth patterns.     

Oncological outcomes of operative treatment of subcutaneous soft-tissue sarcomas of the extremities

We reviewed the cases of sixty-two patients who had had a subcutaneous sarcoma to determine the effect of tumor and treatment-related variables on the rates of survival and local recurrence. Fifty-nine (95 per cent) of the patients had had an operation at another hospital before being referred to us. Twenty-nine (47 per cent) of the sixty-two tumors were high-grade, forty-two (68 per cent) were small (five centimeters or less), and thirty (48 per cent) were malignant fibrous histiocytomas. We followed a treatment strategy that consisted of repeat excision with the goal of obtaining wide margins. Excluding thirteen patients who had had a palpable local recurrence at the time of presentation, twenty (49 per cent) of forty-one patients who had had a marginal excision at another hospital had microscopic residual tumor on repeat excision. At a median of fifty-six months after the repeat excision, fifty (81 per cent) of the sixty-two patients had been continuously disease-free, one had no evidence of disease, eight had died of the disease, and three had died of other causes. The five-year rate of disease-free survival was 85 per cent (fifty-three of sixty-two patients). There were three local recurrences, all in patients who had had a marginal resection. No recurrences were noted in patients who had had a wide local excision of the tumor or of the previous operative field. Multivariate analysis revealed that a large tumor (greater than five centimeters), a marginal excision, and adjuvant radiation therapy were associated with a worse prognosis. Excellent rates of survival for patients who have a subcutaneous sarcoma, including those who have a large or high-grade tumor and those who have residual tumor following a previous operation, can be obtained with carefully planned operative treatment alone. We recommend operative excision or repeat excision with wide margins because of the high prevalence of residual tumor. Size is the most important tumor-related factor, and the operative margin is the most important treatment-related factor. The additional value of adjuvant radiation therapy remains unproved.     

Intracranial and spinal dissemination of an ACTH secreting pituitary neoplasia. Case report and review of the literature

Smoking is associated with insulin resistance, dyslipidaemia and markers of the insulin resistance syndrome. This study investigated adipose tissue lipolysis in situ by subcutaneous microdialysis twice in 10 healthy, male smokers after smoking four cigarettes over 2 h and after the administration of an equal amount of nicotine given as nasal spray (NNS). Glucose and insulin levels, in situ lipolysis and adipose tissue blood flow were studied in the post-absorptive state and after a 75-g oral glucose tolerance test (OGTT). Post-absorptively, acute smoking and NNS increased neither subcutaneous adipose tissue glycerol production nor plasma free fatty acid (FFA) or glycerol levels. After the OGTT, plasma insulin and lactate levels were significantly higher after smoking, whereas FFA levels were higher after NNS. Normal smoking or the administration of a normal dose of NNS caused only minor metabolic changes. Thus, it does not seem likely that increased lipolysis is an important contributor to the dyslipidaemia seen in smokers.     

Expression of recombinant antigens in Escherichia coli: application on immunochemical studies of Schistosoma mansoni tegumental antigens

Sm15 and Sm13 are recognized by antibodies from mice protectively vaccinated with tegumental membranes, suggesting a potential role in protective immunity. In order to raise antibodies for immunochemical investigations, the genes for these antigens were expressed in pGEX and pMal vectors so that comparisons could be made among different expression systems and different genes. The fusion proteins corresponding to several parts of the gene for the precursor of Sm15 failed in producing antibodies recognizing the parasite counterpart. On the other hand, antibodies raised against Sm13 MBP-fusion proteins recognized the 13 kDa tegumental protein. Thus the peculiarities of the gene of interest are important and the choice of the expression system must sometimes be decided on an empirical basis.     

NG2 proteoglycan and the actin-binding protein fascin define separate populations of actin-containing filopodia and lamellipodia during cell spreading and migration

The transmembrane proteoglycan NG2 is able to interact both with components of the extracellular matrix and with the actin cytoskeleton. An examination of the distribution of NG2 during cell spreading suggests that NG2 can associate with two distinct types of actin-containing cytoskeletal structures, depending on the nature of the stimulus derived from the substratum. On fibronectin-coated dishes, cell surface NG2 associates exclusively with stress fibers developing within the cell. On poly-L-lysine-coated dishes, cell surface NG2 is associated with radial processes extending from the cell periphery. Spreading on fibronectin/poly-L-lysine mixtures, as well as on matrix components such as laminin, tenascin, and type VI collagen, produces cells with mosaic characteristics, i.e., NG2 is associated with both types of structures. NG2-positive radial processes are distinct from a second population of radial structures that contain fascin. NG2-positive extensions appear to be individual self-contained units (filopodia), whereas fascin is associated with actin ribs within sheets of membrane (lamellipodia). NG2- and fascin-positive structures are often localized to opposite poles of spreading cells, suggesting a possible role for the two classes of cellular extensions in the establishment of cell polarity during morphogenesis or migration. Time lapse imaging confirms the presence of lamellipodia on the leading edges of migrating cells, while numerous filopodia are present on trailing edges.