Screening for BRCA1 and BRCA2 mutations among French-Canadian breast cancer cases attending an outpatient clinic in Montreal.

Study subjects were French-Canadian women with ductal carcinoma in situ (DCIS) or invasive breast cancer (incident or prevalent) who were treated and followed at a single breast cancer clinic affiliated with the Research Center of University of Montreal (CRCHUM), who were either aged less than 50 years at diagnosis or who were 50 years or older and with at least two affected first- or second-degree relatives. Subjects were tested for six founder mutations (three in BRCA1 and three in BRCA2); 1093 eligible cases were tested. Of these, 56 women (5.1%) were mutation carriers, including 43 BRCA2 carriers and 13 BRCA1 carriers. The prevalence of mutations was 5.3% for unselected women aged 50 and less and was 4.6% for familial cases over age 50. The prevalence of mutations was 3.3% for women with DCIS and was 5.3% for women with invasive cancer. It is rational to offer genetic testing to all French-Canadian women diagnosed recently or in the past with either DCIS or invasive breast cancer before age 50 or with familial breast cancer above age 50.

The contribution of founder mutations to early-onset breast cancer in French-Canadian women.

In an ethnically-homogeneous population, it is valuable to identify founder mutations in cancer-predisposing genes. Founder mutations have been found in four breast-cancer-predisposing genes in French-Canadian breast cancer families. The frequencies of the mutant alleles have been measured neither in a large series of unselected breast cancer patients from Quebec, nor in healthy controls. These estimates are necessary to measure their contribution to the hereditary burden of breast cancer in Quebec and to help develop genetic screening policies which are appropriate for the province. We studied 564 French-Canadian women with early-onset invasive breast cancer who were treated at a single Montreal hospital. Patients had been diagnosed at age 50 or less, and were ascertained between 2004 and 2008. We screened all 564 patients for nine founder mutations: four in BRCA1, three in BRCA2 and one each in PALB2 and CHEK2. We also studied 6433 DNA samples from newborn infants from the Quebec City area to estimate the frequency of the nine variant alleles in the French-Canadian population. We identified a mutation in 36 of the 564 breast cancer cases (6.4%) and in 35 of 6443 controls (0.5%). In the breast cancer patients, the majority of mutations were in BRCA2 (54%). However, in the general population (newborn infants), the majority of mutations were in CHEK2 (54%). The odds ratio for breast cancer to age 50, given a BRCA1 mutation, was 10.1 (95% CI: 3.7-28) and given a BRCA2 mutation was 29.5 (95% CI: 12.9-67). The odds ratio for breast cancer to age 50, given a CHEK2 mutation, was 3.6 (95% CI: 1.4-9.1). One-half of the women with a mutation had a first- or second-degree relative diagnosed with breast or ovarian cancer. Thus, it can be concluded that a predisposing mutation in BRCA1, BRCA2, CHEK2 or PALB2 is present in approximately 6% of French-Canadian women with early-onset breast cancer. It is reasonable to offer screening for founder mutations to all French-Canadian women with breast cancer before age 50. The frequency of these mutations in the general population (0.5%) is too low to advocate population-based screening.

Among-environment heteroscedasticity and genetic autocorrelation: implications for the study of phenotypic plasticity.

The impact of among-environment heteroscedasticity and genetic autocorrelation on the analysis of phenotypic plasticity is examined. Among-environment heteroscedasticity occurs when genotypic variances differ among environments. Genetic autocorrelation arises whenever the responses of a genotype to different environments are more or less similar than expected for observations randomly associated. In a multivariate analysis-of-variance model, three transformations of genotypic profiles (reaction norms), which apply to the residuals of the model while preserving the mean responses within environments, are derived. The transformations remove either among-environment heteroscedasticity, genetic autocorrelation or both. When both nuisances are not removed, statistical tests are corrected in a modified univariate approach using the sample covariance matrix of the genotypic profiles. Methods are illustrated on a Chlamydomonas reinhardtii data set. When heteroscedasticity was removed, the variance component associated with the genotype-by-environment interaction increased proportionally to the genotype variance component. As a result, the genetic correlation rg was altered. Genetic autocorrelation was responsible for statistical significance of the genotype-by-environment interaction and genotype main effects on raw data. When autocorrelation was removed, the ranking of genotypes according to their stability index dramatically changed. Evolutionary implications of our methods and results are discussed.

Classification of type-II restriction endonucleases and cloning of non-identical cohesive-end fragments without self-polymerization using nonpalindromic oligodeoxyribonucleotide adapters.

Enzymatic partial filling-in of recessed 3'-end sequences, left after digestion of DNA by the restriction endonucleases (ENases) Sau3A and SalI, with the Klenow fragment of E. coli DNA polymerase I allows the forced ligation of the resulting fragments; this technology is already used for subcloning and for genomic bank construction. To simplify and generalize its utilization, class-II ENases have been arranged into 16 different families according to the composition of the 5'-protruding sequences present after cleavage. Moreover, this system was extended to allow the joining of noncompatible ends by the use of nonpalindromic complementary oligodeoxyribonucleotides (NPCOs) containing two nucleotides protruding at each 5' end. The use of these synthetic adapters maintains all the advantages of the initial gap-filling cloning technique: only one insert can be cloned per vector molecule and no self-ligation or -polymerization can occur with any of the DNA molecules involved. Only 22 such oligodeoxyribonucleotides are needed to generate the 60 NPCO pairs necessary to ligate to each other any member of twelve ENase families when the regeneration of ENase recognition sites is not required.

High-yield method for directional cDNA library construction.

Improvement of a cDNA synthesis procedure using a single stranded (ss) vector primer [Bellemare et al., Gene 52 (1987) 11-19] is reported. This vector (pPBS27), upon linearization with XbaI using an appropriate restriction site-directed fragment, releases a thymidilic tail used to prime cDNA synthesis. DNA polymerase I and RNase H replace the RNA strand and replicate the vector before double-stranded (ds) blunt-end ligation with T4 DNA ligase. More than 10(7) cfu/microgram of vector can be obtained with an efficient transformation protocol using either globin-encoding or 7.5-kb poly(A)-tailed RNA. This improved cloning method is easier, faster and a few hundred times more efficient than the original procedure as it involves ds rather than ss DNA for transformation.

Use of a phage vector for rapid synthesis and cloning of single-stranded cDNA.

We have developed a technique for synthesis of single stranded complementary DNA (ss cDNA) using specifically designed phage ssDNA as vector primer. This vector (pPBS27) was constructed by introducing a poly(dT) tail adjacent to the XbaI site of pTZ18R, which can exist either as a plasmid in Escherichia coli or as a ssDNA phage. The pPBS27 phage vector is linearized with XbaI using a restriction-site-directed fragment and used to anneal a mixture of poly(A) + RNA for cDNA synthesis by reverse transcriptase. The RNA is then hydrolysed with NaOH and a poly(dG) tail added to the 3' end of the vector-cDNA with terminal transferase. The linear hybrid ssDNA is then closed by annealing with a 15-mer site-directed fragment oligodeoxynucleotide molecule and ligated with T4 DNA ligase. Almost 10(5) E. coli transformants per microgram of vector primer can be obtained in two days.

Detection and localization of parathyroid adenomas in patients with hyperparathyroidism using a single radionuclide imaging procedure with technetium-99m-sestamibi (double-phase study)

Dual radionuclide imaging using a combination of 201Tl with either 99mTcO4- or 123I is recognized as a useful procedure in the preoperative localization of parathyroid adenomas. Recently, 99mTc-sestamibi (MIBI) has been introduced for myocardial perfusion imaging as an alternative to 201Tl. The purpose of this prospective study was to evaluate parathyroid scan using early and late imaging following MIBI injection. Twenty-three patients (21 F, 2 M, mean age: 57 yr) with a clinical and biologic diagnosis of hyperparathyroidism were submitted to a MIBI study prior to surgical exploration of the neck. Cervico-thoracic planar imaging (anterior view, 10 min/view) was performed at 15 min and at 2-3 hr after an intravenous injection of 20-25 mCi of MIBI. A positive MIBI scan for parathyroid adenoma was defined as an area of increased focal uptake which persisted on late imaging, contrary to the uptake in the normal thyroid tissue which progressively decreases over time (differential washout). Surgical exploration of the neck, performed between 1 day and 72 days (average: 16 days) after the MIBI study, showed a parathyroid adenoma in 21 patients and hyperplasia in two patients. MIBI scan correctly detected and localized 19/21 adenomas (90%). In conclusion, parathyroid imaging using a single radionuclide with MIBI (early and late study with differential washout analysis) is a promising procedure in the preoperative detection and localization of parathyroid adenomas in patients with primary hyperparathyroidism.

Androgen regulation of canine prostatic arginine esterase mRNA using cloned cDNA.

Canine prostatic arginine esterase complementary DNA has been cloned in pPBS27, a new cloning vector. The relative abundance of androgen-regulated mRNA in intact dog prostate was reflected by the finding that a high proportion of the clones in the cDNA library hybridized strongly by plaque or colony hybridization with a poly(A)+ RNA probe from intact dog prostate but not with a poly(A)+ RNA probe from castrated dog prostate. One clone carrying a 400 base pairs cDNA insert was selected for further studies. Translation of the hybrid-selected RNA in a cell-free system resulted in the production of a 31 kDa peptide immunoprecipitable by antibodies against arginine esterase. This identification was confirmed by partial sequence analysis of the cDNA revealing an encoding protein with high homology to known kallikreins. Northern blot analysis of poly(A)+ and total RNA showed that arginine esterase mRNA had an approximate size of 1.0 kb which corresponded to a major androgen-regulated RNA species that could be observed after denaturing agarose gel electrophoresis of prostatic poly(A)+ RNA from intact dogs. Dot-blot analysis showed that dogs which had been castrated 3 weeks before had more than 100-fold lower arginine esterase mRNA level than intact dogs or castrated dogs treated with Depo-testosterone.

In vitro lymphocyte reactivity and T cell levels in patients with melanoma: correlations with clinical and pathological stage.

In vitro lymphocyte reactivity (LR) to phytohemagglutinin (PHA) and peripheral blood thymus-dependent lymphocyte (T cell) levels were determined in 42 tumor-bearing patients with clinically operable melanoma and were compared to 41 age-matched normal controls. Patients with tumors clinically confined to the primary site (Stage I) as a group had normal immune reactivity and T cell levels, and those with regional metastases by clinical assessment (Stage II) had relatively impaired LR and T cell levels. In six of 24 patients with clinical Stage II tumors, widespread metastases (Stage III) subsequently were found. The severe immune defects in this group with occult disseminated melanoma accounted for the impaired LR and low T cell levels in the group with clinical Stage II tumors. Although overlapping levels of LR and T cells in the patients with pathological Stage II and III tumors prevent use of the data as a determinant of tumor extent in individual patients, the results show that these in vitro assays define a relation between cellular immunocompetence and tumor burden in patients with melanoma.

Early experience with laparoscopic approach for adrenalectomy.

BACKGROUND: Adrenalectomy performed by a posterior or transabdominal approach causes substantial postoperative pain. The purpose of this study was to evaluate laparoscopy as a potential approach for adrenalectomy. METHODS: We performed 25 consecutive laparoscopic adrenalectomies on 22 patients from April 1, 1992, to March 30, 1993. Laparoscopic surgery was performed by using a lateral decubitus flank approach with four 11 mm trocars. RESULTS: Twelve right and 13 left adrenal glands were removed in a mean time of 2.3 hours. Three patients underwent bilateral adrenalectomies in a mean time of 5.3 hours. The 15 women and 7 men range in age from 31 to 60 years (mean, 42 years). The adrenal gland diseases were nonfunctional adenoma (seven), pheochromocytoma (five), Cushing's disease (four), Cushing's adenoma (four), primary aldosteronism (two), dehydroepiandrostenedione sulfate hypersecretion (one), angiomyolipoma (one), and medullary cyst (one). Average tumor size was 4.1 cm (range, 1 to 15 cm). Laparoscopic adrenalectomy was successful in 96% of patients, with one patient requiring a laparotomy because of inadequate exposure. The median postoperative stay was 4 days (range, 2 to 19), with a mean of five narcotic injections. There were no deaths, and morbidity was minor. CONCLUSIONS: Laparoscopy can be used successfully for adrenalectomy. It produces less postoperative pain and rapid return to normal activity. It may be the preferred method for removing most adrenal gland lesions that require operation.

Multiple primary malignant neoplasms. A search for an immunogenetic basis.

The occurrence of multiple primary malignant neoplasms in single individuals is well documented. Although many hypotheses have been advanced to explain this occurrence, there has been no study to determine if a presumed "increased susceptibility to cancer" has an immunogenetic basis. We evaluated the cellular immunity and histocompatibility antigens of 42 patients who had had from two to four multiple primary malignant neoplasms. We failed to demonstrate a preexisting impairment of immunocompetence or abnormal HL-A antigen frequencies in these patients. The occurrence of multiple primary malignant neoplasms in related tissues, eg, lung/larynx/oral cavity, and the occurrence of successive primary malignant neoplasms at a time interval consistent with the patient's being cured of preceding malignant neoplasms suggest that multiple primary malignant neoplasms result from repetitive induction by the same or similar etiologic factors in patients who are cured after treatment of the first malignant neoplasm.

T rosette assay: in vitro correlate of cellular immunity.

The T rosette assay, based on the capacity of thymus-derived lymphocytes (mediators of tumor-inhibiting immunity) to bind sheep erythrocytes in vitro, was used to quantitate percentages of T rosette-forming lymphocytes in the peripheral blood of 38 patients with urologic cancer. Results obtained using the T rosette assay yielded statistically significant direct correlations with those obtained using two other assays which have been widely employed to monitor cellular immunity: elicitation of delayed hypersensitivity to DNCB (dinitrochlorobenzene) and the proliferative response of lymphocytes to PHA (phytohemagglutinin). The findings suggest the T rosette assay provides a meaningful in vitro correlate of cellular immunity.

Low night temperature effect on photosynthate translocation of two C4 grasses.

Translocation of assimilates in plants of Echinochloa crus-galli, from Quebec and Mississippi, and of Eleusine indica from Mississippi was monitored, before and after night chilling, using radioactive tracing with the short-life isotope 11C. Plants were grown at 28°/22°C (day/night temperatures) under either 350 or 675 µl·l-1 CO2. Low night temperature reduced translocation mainly by increasing the turn-over times of the export pool. E. crus-galli plants from Mississippi were the most susceptible to chilling; translocation being completely inhibited by exposure for one night to 7°C at 350 µl·l-1 CO2. Overall, plants from Quebec were the most tolerant to chilling-stress. For plants of all three populations, growth under CO2 enrichment resulted in higher 11C activity in the leaf phloem. High CO2 concentrations also seemed to buffer the transport system against chilling injuries.

The immunobiology of skin cancer.

The immunobiology of skin cancer was studied with thymus-dependent lymphocyte (T cell) levels (an in vitro measure of cellular immunity), with lymphocytic infiltration (LI) of the tumor (an in vivo measure of host-tumor relationship), and with HL-A typing (a genetic measure of histocompatibility). The T cell levels in preoperative patients with squamous (SCC) and basal (BCC) cell carcinoma were significantly lower than in the non-cancer control population (normals). The T cell levels were significantly lower in patients with large tumors than in those with small tumors. The T cell levels remained significantly low in patients cured of large tumors, but were normal in those cured of small tumors. Patients with Bowen's disease not only had T cell levels significantly lower than normal (as a group), but there was also a significant increase in the number of patients who had T cell levels less than two standard deviations below the normal mean. This may signify that they have a greater risk of developing a second kind of malignancy elsewhere. There was a direct correlation between the degree of lymphocytic infiltration (LI) of the tumor, the tumor size, and the T cell level. Small, well-localized tumors had a marked LI and high T cell levels--while the large, deeply invasive tumors had a minimal, or absent, LI and low T cell levels. The presence of HL-A antigens 1 and 8 correlated both with a tendency toward large tumors and with low T cell levels. This may represent the association of a human immune response gene with the human histocompatibility locus. Possibilities for the application of these findings in the clinical management of skin cancer are discussed.

[Quality of life of patients after restorative surgery for cancer of the rectum]. / Qualité de vie des patients opérés à visée curative pour un cancer du rectum.

During the last decades surgeons have put a tremendous effort to perform low anterior resection (LAR) as a curative procedure for rectal cancer treated classically by abdomino-perineal resection (APR) and permanent colostomy. A psychological evaluation testing the multi-dimensional concept of quality of life was done in 32 patients (M = 21; F = 11) treated by APR and compared to 28 patients (M = 16; F = 12) treated by LAR. Patients were assessed for quality of life on the following dimensions: physical well-being, psychological well-being, dietary habits, surgical response, social concerns, body image, stress and marital adjustment. Using as covariables social support and time elapsed since surgery, a covariate analysis was used to determine the presence of group ans sex interaction. Patients with LAR had a better body image (p.001), dietary habits (p.003) and tolerance to stress (p.004). Better global quality of life (p.001), physical well being (p.001) and less surgical sequela (p.001) were found with LAR in women only. No significant difference was found on psychological well being, social concerns and marital adjustment in both surgical groups.

The research utilization process: the use of guided imagery to reduce anxiety.

In the rapidly changing health care environment, nurses need to keep current with developments, assess their applicability to practice, and make changes where appropriate. There is evidence that nursing research is underutilized and that a considerable gap exists between nursing research and practice (Bostrum & Suter, 1993; Brett, 1987; Sokop & Coyle, 1990). The objectives of a study carried out on a bone marrow transplant unit in a teaching hospital were to: (1) by introducing a framework for research-based care, enhance research utilization in a selected setting, and (2) evaluate the outcomes of research utilization on a specific clinical nursing problem chosen by nurses and researchers. This paper describes the research utilization process and its outcomes, presents an evaluation of the participatory approach from the perspective of the participating nurses, and discusses facilitators and barriers to research utilization. Guided imagery was the intervention used to decrease patient anxiety.

Linking the professional literature to nursing practice: challenges and opportunities.

Occupational health nurses face the challenge of rapidly changing, increasingly complex work environments. To respond, they must have access to information and know how to manage it effectively to improve their clinical performance and achieve better client outcomes. Information technology has already had an impact on nursing. Many nurses routinely use computers to access laboratory reports, client records, and administrative programs. However few nurses make use of opportunities provided by information technology to access professional literature as a tool for applying new research to their practice.

Effect of Leaf Detachment on Chlorophyll Fluorescence during Chilling Experiments.

The effect of leaf detachment on chlorophyll fluorescence was analyzed for Zea mays, Cucumis sativus, Phaseolus vulgaris, and Echinochloa crus-galli. Results clearly indicate that detachment hastens the decrease in chlorophyll fluorescence during the course of chilling experiments. For maize and bean, the activity of photosystem II of chloroplasts isolated from detached leaves is lower than that of chloroplasts isolated from attached leaves. There are also large differences in ionic loss between detached and attached leaves of barnyard grass which could correlate with changes in leaf water status. The detached leaves lost some 50% of their total ionic content. Finally, detachment alters the ranking of the species with regard to their chilling tolerance.

Lacustrine spatial distribution of landlocked Atlantic salmon populations assessed across generations by multilocus individual assignment and mixed-stock analyses.

The objective of this study was to assess the spatiotemporal distribution of four landlocked Atlantic salmon (Salmo salar) populations during their sympatric feeding phase in lake St-Jean (Québec, Canada). A total of 1100 fish captured over a period of 25 years was genotyped at six microsatellite loci in order to assess the temporal stability of the relative proportion of each population in different lake sectors using both individual-based assignment and mixed-stock analysis. Estimates of relative proportions obtained from both methods were highly correlated. A nonrandom spatial distribution of populations was observed for each period and, despite the fact that the overall proportion of each population varied over time, the pattern of differential distribution remained generally stable over time. Furthermore, there were indications that the extent of horizontal spatial overlap among populations was negatively correlated with that of their genetic differentiation at both microsatellites and a major histocompatibility complex locus, and independent of the geographical distance between the rivers of origin. We discuss the hypothesis that the temporal stability of spatial distribution, the lack of an association between spatial partitioning and geographical distance between rivers of origin, and the apparent negative correlation between spatial overlap and genetic differentiation, reflect the outcome of selective pressures driving behavioural differences for spatial niche partitioning among populations.

Chemical DNA sequencing in the opposite direction to the dideoxy chain termination method, using a single preparation of M13 single-stranded DNA.

A strategy has been developed allowing the use of a single preparation of single-stranded DNA clones for chemical DNA sequencing in the opposite direction to the classical dideoxy chain termination method. Oligonucleotide complementary to the 5'-end of the multipurpose cloning sequence, with the proper restriction enzyme, is used to cleave specifically the molecules to expose a unique 5'-end, upstream to the inserted DNA, for the kinase labeling reaction. No further treatments are necessary before Maxam-Gilbert chemical sequencing reactions.