Direct contact in inviting high-risk members of hereditary colon cancer families to genetic counselling and DNA testing

Background

Identification of hereditary predisposition to cancer has limited significance if not followed by efficient cancer prevention in the family. Probands are traditionally left to inform their relatives about the increased risk, but distant relatives may remain uninformed. An approach to contacting directly at‐risk persons assumed to be unaware of their increased cancer risk was taken. With cancer prevention as the ultimate goal, the study was aimed at investigating attitudes towards and psychosocial consequences of this novel strategy.

Methods

In families with hereditary non‐polyposis colorectal cancer (Lynch syndrome), 286 healthy adult relatives with a 50% risk of a predisposing mutation were contacted by letter. Of these, 112 participated in counselling and predictive testing. Baseline information and information obtained 1 month after the test for 73 respondents were compared with 299 corresponding subjects, approached via the proband (family‐mediated approach in our previous study) in these families.

Results

After the contact letter, 51% consented to the study. Of these, 92% approved of the direct contact and 33% had tried to seek information. In 34% of the mutation carriers, neoplasia was identified in the first post‐test colonoscopy. Although post‐test fear of cancer increased among the mutation carriers and decreased among noncarriers, almost all participants were satisfied with their decision to participate, independently of their test results, parallel to the family‐mediated approach.

Conclusion

In this large‐scale study, relatives in cancer families were actively contacted to inform them of the condition and genetic counselling. Their attitudes were encouraging, and the psychosocial consequences were similar to the family‐mediated approach. Our results suggest the appropriateness of direct contact as an alternative method of contact in cases of life‐threatening treatable disease.     

Alpha4 chain laminins are widely expressed in renal cell carcinomas and have a de-adhesive function

Laminin (Lm) alpha4 chain, a constituent of Lm-411 and Lm-421, is mainly localized to mesenchyme-derived tissues, and is suggested to have a role in formation and function of endothelium, transmigration of inflammatory cells through endothelium, and invasion of certain tumors. In this study, we evaluated the distribution of alpha4 chain Lms in 33 conventional (clear cell) renal cell carcinomas (RCCs) (31 primary tumors, two metastases), two papillary RCCs, and two oncocytomas by immunohistochemistry. In all tumors, immunoreactivity for Lm alpha4 chain was found in vasculature and stroma. Basement membranes were detected around tumor cell islets in 34/37 tumors. They showed immunoreactivity for Lm alpha4 chain in 28/34 cases. Northern blotting, inhibition of protein secretion with monensin, and immunoprecipitation combined with Western blotting showed that Caki-2, ACHN, and Caki-1 renal carcinoma cell lines produce alpha4 chain Lms. In cell adhesion assay, recombinant human Lm-411 did not promote adhesion of renal carcinoma cells but inhibited adhesion to fibronectin (Fn). In cell migration assay, the cells migrated more on Lm-411 than on Fn. The results suggest that alpha4 chain Lms have a de-adhesive function and could thus play a role in detachment, migration and invasion of renal carcinoma cells in vivo.     

Novel homogenous time-resolved fluorometric RT-PCR assays for quantification of PSA and hK2 mRNAs in blood

Objectives:The purpose of this study was to design, validate, and optimize internally standardized real-time quantitative RT-PCR assays and to identify and avoid problems with assay reliability and examine the impact of an exogenous internal standard.Design and methods:The model system consisted of internally standardized quantitative real-time RT-PCR assays specific for PSA and hK2 mRNA based on time-resolved fluorometric detection of lanthanide chelates.Results:Reproducibility was best when large copy numbers (> 5000 per milliliter blood) were analyzed. Addition of an exogenous target-mimicking internal standard had no significant effect on the reproducibility of the method, but increased the calculated copy numbers by an average of 2-fold.Conclusions:We developed an internally standardized, specific and reproducible real-time RT-PCR analysis method for PSA and hK2 mRNA in circulating cells in the bloodstream. Both PSA and hK2 assays are sufficiently sensitive to detect two LNCaP cells per milliliter whole blood.     

Singapore Paediatric Resuscitation Guidelines 2021

We present the 2021 Singapore Paediatric Resuscitation Guidelines. The International Liaison Committee on Resuscitation’s Pediatric Taskforce Consensus Statements on Science and Treatment Recommendations, which was published in October 2020, and the updated resuscitation guidelines from the American Heart Association and European Resuscitation Council, were reviewed and discussed by the committee. These recommendations were derived after deliberation of peer-reviewed evidence updates on paediatric resuscitation and took into consideration the local setting and clinical practice.