519 research outputs found

    Medicine and the Law: Partial relief from the regulatory vacuum involving human tissues through enactment of chapter 8 of the National Health Act and regulations thereto

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    Human tissue legislation is complex. An exhaustive understanding of the law, thorough understanding of human tissue biology and pathophysiology and an appreciation of the diversity of the areas covered in this field, is critical. The importance of interdisciplinary co-operation in the drafting, interpretation and implementation of legislation in this area cannot be overemphasised. Severalfactors underscore this, including the complexity and volume of the information involved, rapid advances in science, reciprocal dependence of the law and science on one another for relevance and accuracy, and above all the need to ensure that the patient’s well-being and safety are not compromised. The development of technology also must be encouraged in a non-obstructive legislative setting

    Is South Africa on the verge of a medical malpractice litigation storm?

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    South Africa is witnessing a sharp increase in medical malpractice litigation as patients increasingly become aware of their rights in a setting of an overburdened health system with limited resources. Legitimate claims need to be compensated. However, the consequences of increased litigation are: (i) a further reduction in the state’s ability to finance health care as a result of large payouts; and (ii) a continuing increase in malpractice premiums in the private sector. A healthy tension between the medical and legal professions should lead to an overall improvement in quality of health care, but consideration will need to be given to issues such as specialist courts, alternative means of resolution, claim quantum determination and capping. Although these issues will technically not minimise the risk of negligence, they may assist in tempering the increasing litigation spiral. Adequate allocation of funding by the state will reduce the risk of claims against the state that result from inadequate human and other resources; this is an important political/policy debate that speaks indirectly to the litigation issue. The recent implementation of the Consumer Protection Act will increasingly place additional and direct responsibility on health professionals for claims made by patients for which they may be directly or indirectly held responsible

    A global comparative overview of the legal regulation of stem cell research and therapy: Lessons for South Africa

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    Stem cell research and its potential translation to regenerative medicine, tissue engineering and cell and gene therapy, have led to controversy and debates similar to the calls nearly 25 years ago for a ban involving recombinant DNA. Global legislative efforts in this field have been characterised by many legal, ethical and practical challenges, stemming from conflicting views regarding human embryonic research and cloning. National policy and regulatory developments have primarily been shaped by different understandings of relevant scientific objectives, as well as those relating to the moral and legal status of the human embryo, which have been used to justify or limit a range of permissible activities. Legal obscurity in this field, a consequence of inconsistent or vague legislative responses at a national and international level, leads to negative results, which include, among others, ethical violations; lack of collaboration and co-operation among researchers across national borders; stunted scientific progress; lack of public trust in stem cell research; proliferation of untested ‘stem cell therapies’; and safety issues. The purpose of this article is to explore the legal regulation of stem cell research and therapy globally, by comparing the permissibility of specific stem cell research activities in 35 selected jurisdictions, followed by a comparison of the regulatory approaches with regard to stem cell-based products in the European Union and the USA. A clearer understanding of the global regulatory framework will assist in formulating more effective legal responses at a national level and in navigating the uncertainties and risks associated with this complex and evolving scientific field

    HLA typing: Conventional techniques v. next-generation sequencing

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    Background. The large number of population-specific polymorphisms present in the HLA complex in the South African (SA) population reduces the probability of finding an adequate HLA-matched donor for individuals in need of an unrelated haematopoietic stem cell transplantation (HSCT). Next-generation sequencing (NGS) has numerous advantages compared with conventional typing techniques.Objective. To evaluate whether NGS can provide any additional value over conventional techniques in the SA context for the purpose of HSCT and cord blood banking.Methods. HLA genotyping was performed using NGS on 20 samples that had previously been HLA typed by conventional methods to evaluate whether NGS might provide any additional value over conventional HLA determination techniques.Results. NGS of routinely sequenced loci and exons yielded accurate genotypes for 98.5% of the five loci of interest, compared with 98% when additional exons were included.Conclusion. The study shows that the additional value of NGS over conventional techniques is limited, and unless done on a large scale to reduce cost may not be appropriate in SA at this stage in the context of HSCT and cord blood banking

    The legal position on the classification of human tissue in South Africa: Can tissues be owned?

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    The ownership of tissue samples donated for medical research is an ongoing subject of dispute. Some advocates assert that patients have ongoing ownership rights in their tissues, including an unfettered right to determine what happens to their tissue sample. Researchers argue that giving patients property rights in their samples will turn the human body and body parts into a commodity and bring research to a halt. The question of the human body as property involves complex and philosophical dimensions. The law displays an uneasiness in making sense of the human body in the context of ownership and property, as the notion of owning oneself (and one’s tissues) implies that persons are able to objectify their selves, and in the process become susceptible to objectification by others. The creation of commercial products from human tissue has generated very difficult legal and ethical questions that have no clear, universally accepted answers

    A novel cardiovascular magnetic resonance risk score for predicting mortality following surgical aortic valve replacement

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    The increasing prevalence of patients with aortic stenosis worldwide highlights a clinical need for improved and accurate prediction of clinical outcomes following surgery. We investigated patient demographic and cardiovascular magnetic resonance (CMR) characteristics to formulate a dedicated risk score estimating long-term survival following surgery. We recruited consecutive patients undergoing CMR with gadolinium administration prior to surgical aortic valve replacement from 2003 to 2016 in two UK centres. The outcome was overall mortality. A total of 250 patients were included (68 ± 12 years, male 185 (60%), with pre-operative mean aortic valve area 0.93 ± 0.32cm2, LVEF 62 ± 17%) and followed for 6.0 ± 3.3 years. Sixty-one deaths occurred, with 10-year mortality of 23.6%. Multivariable analysis showed that increasing age (HR 1.04, P = 0.005), use of antiplatelet therapy (HR 0.54, P = 0.027), presence of infarction or midwall late gadolinium enhancement (HR 1.52 and HR 2.14 respectively, combined P = 0.12), higher indexed left ventricular stroke volume (HR 0.98, P = 0.043) and higher left atrial ejection fraction (HR 0.98, P = 0.083) associated with mortality and developed a risk score with good discrimination. This is the first dedicated risk prediction score for patients with aortic stenosis undergoing surgical aortic valve replacement providing an individualised estimate for overall mortality. This model can help clinicians individualising medical and surgical care. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00930735 and ClinicalTrials.gov Identifier: NCT01755936

    Fibroblasts—a key host cell type in tumor initiation, progression, and metastasis

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    Tumor initiation, growth, invasion, and metastasis occur as a consequence of a complex interplay between the host environment and cancer cells. Fibroblasts are now recognized as a key host cell type involved in host–cancer signaling. This review discusses some recent studies that highlight the roles of fibroblasts in tumor initiation, early progression, invasion, and metastasis. Some clinical studies describing the prognostic significance of fibroblast-derived markers and signatures are also discussed

    A model for co-expression pattern analysis of genes implicated in angiogenesis and tumour cell invasion in cervical cancer

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    To date, numerous genes have been identified which are involved in both tumour neovascularisation (angiogenesis) and tumour cell invasion, and most of them are also expressed to some extent under normal physiological conditions. However, little is known about how these genes co-express in these settings. This study was undertaken to quantitate mRNA levels in normal and malignant cervical tissues of nine selected genes (VEGF121, VEGF165, VEGF189, VEGF-C, eIF-4E, b-FGF, TSP-2, MMP-2 and MMP-9) implicated in the above processes using real-time quantitative RT–PCR. In addition, the Spearman's rank correlation was used to determine their co-expression patterns. The transcript levels for the different VEGF-A splice variants (VEGF121, VEGF165, VEGF189) were at least 10-fold higher in the cancer cases, with the highest levels in the primary tumours demonstrating lympho-vascular space involvement. The lymphangiogenic factor VEGF-C and MMP-9 were upregulated 130- and 80-fold respectively in cervical cancers. The highest levels of VEGF-C mRNA were found in the lymph-node positive group. The transcript levels for b-FGF were similar in normal cervical tissue and early-stage cervical cancer, however, higher levels were found in the cervical cancers with advanced stage disease. Comparing gene transcript levels between recurrent and non-recurrent cervical cancer patients revealed significant differences (P=0.038) in transcript levels for the angiogenesis inhibitor TSP-2, with the highest levels in non-recurrent cases. Co-expression pattern analysis in normal cervical tissue revealed highly significant co-expressions (P<0.0001) between TSP-2 and most other genes analysed (VEGF121, VEGF165, VEGF-C, b-FGF and MMP-2). In cervical cancer, TSP-2 appears only to be highly co-expressed with MMP-2 (P<0.0001). In contrast to normal cervical tissue, we found a highly significant co-expression (P<0.0001) between MMP-9 and VEGF189 in cervical cancer. The combined application of real-time quantitative RT–PCR and Spearman's rank correlation identifies gene transcripts which are simultaneously co-expressed. Our results revealed a significant co-expression between the angiogenesis inhibitor TSP-2 and most other genes analysed in normal cervical tissue. In cervical cancer, we found a strong upregulation of VEGF-C and MMP-9 mRNA, with a highly significant co-expression between MMP-9 and VEGF189

    BIM mediates synergistic killing of B-cell acute lymphoblastic leukemia cells by BCL-2 and MEK inhibitors

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    B-cell acute lymphoblastic leukemia (B-ALL) is an aggressive hematological disease that kills ~50% of adult patients. With the exception of some BCR-ABL1(+) patients who benefit from tyrosine kinase inhibitors, there are no effective targeted therapies for adult B-ALL patients and chemotherapy remains first-line therapy despite adverse side effects and poor efficacy. We show that, although the MEK/ERK pathway is activated in B-ALL cells driven by different oncogenes, MEK inhibition does not suppress B-ALL cell growth. However, MEK inhibition synergized with BCL-2/BCL-XL family inhibitors to suppress proliferation and induce apoptosis in B-ALL cells. We show that this synergism is mediated by the pro-apoptotic factor BIM, which is dephosphorylated as a result of MEK inhibition, allowing it to bind to and neutralize MCL-1, thereby enhancing BCL-2/BCL-XL inhibitor-induced cell death. This cooperative effect is observed in B-ALL cells driven by a range of genetic abnormalities and therefore has significant therapeutic potential

    Prognostic significance of lymphangiogenesis in pharyngolaryngeal carcinoma patients

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    <p>Abstract</p> <p>Background</p> <p>Lymphatic vessel spread is considered a major route for head and neck squamous cell carcinoma metastasis. Formation of new lymphatic vessels could facilitate the process, raising the malignant potential of these tumours. Recent identification of lymphatic markers allows the study of the lymphangiogenesis phenomenon. We searched for molecular events involved in the lymphangiogenic process that could have prognostic value in laryngeal/pharyngeal carcinoma patients.</p> <p>Methods</p> <p>104 paraffin-embedded pharyngeal/laryngeal tumour samples were studied. Immunohistochemical analysis of podoplanin and double immunofluorescence analysis of Ki-67 and D2-40 were performed. Lymph vessel density (inside the tumour mass, at its periphery or considered as a whole) and the presence of tumour emboli inside lymphatics were recorded. The proliferative state of endothelial lymphatic cells was evaluated.</p> <p>Results</p> <p>Lymphatic vessels were detected inside the tumour mass (75%) and in the surrounding tissue (80%); some of them in a proliferative state. Tumour emboli were detected in a high proportion of the cases (45%). Lymphatic vessel density was higher in the pharyngeal cases (p = 0.0029), in greater size (p = 0.039), more advanced stage primary tumours (p = 0.006) and in carcinomas of patients with affected nodes (p = 0.019). The presence of tumour emboli and a high global vessel density were indicators of poor prognosis (recorded as death from tumour) in the laryngeal group (p = 0.015 and p = 0.027, respectively), but notably not in the pharyngeal one. Interestingly, high global vessel density showed a negative prognostic value among pathologically staged N0 laryngeal carcinomas (p = 0.03).</p> <p>Conclusions</p> <p>The lymphangiogenic process correlated with aggressive tumour features (pN category, tumour size, tumour stage), but might play different roles in tumours arising from different anatomic sites.</p> <p>Our results suggest that detection of tumour emboli and assessment of global vessel density using the D2-40 antibody, may be useful in the clinical practice, as predictors of reduced survival among pN0 laryngeal carcinoma patients.</p
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