HIV-positive status among surgeons - an ethical dilemma

HIV/AIDS is a manageable disease with a reasonable expectation that affected individuals might be able to experience both reduced mortality and morbidity. Within the socio-political context of the illness there has been a very strong emphasis on human rights issues, especially in relation to discrimination, which has seemingly been influenced more by emotion than science. This article explores and addresses the potential risk of an HIV-positive surgeon transmitting the virus to a patient. We argue that the Centers for Disease Control (CDC) and Health Professions Council of South Africa (HPCSA) guidelines are too restrictive, especially against a background of limited transmission risk, and hence that these guidelines could be more harmful than beneficial to our health systems

The impaired practitioner- scope of the problem and ethical challenges

Practitioner impairment occurs when a physical, mental or substance-related  disorder interferes with his or her ability to engage in professional activities  competently and safely. The Health Professions Council of South Africa makes reporting of impaired colleagues and students mandatory. The ethical dilemma faced by many colleagues on the issue of reporting an impaired practitioner is that of having to choose between protecting the privacy of the practitioner and the safety of patients. However, medicine as a profession with an acknowledged fiduciary relationship has a clear responsibility to assure the public, and all patients, that its practitioners and institutions are trustworthy.  An awareness of and sensitivity to physician vulnerability and early detection  and prevention of impairment is important

Comparison of terbium (III) luminescence enhancement in mutants of EF hand calcium binding proteins.

The luminescent isomorphous Ca2+ analogue, Tb3+, can be bound in the 12-amino acid metal binding sites of proteins of the EF hand family, and its luminescence can be enhanced by energy transfer from a nearby aromatic amino acid. Tb3+ can be used as a sensitive luminescent probe of the structure and function of these proteins. The effect of changing the molecular environment around Tb3+ on its luminescence was studied using native Cod III parvalbumin and site-directed mutants of both oncomodulin and calmodulin. Titrations of these proteins showed stoichiometries of fill corresponding to the number of Ca2+ binding loops present. Tryptophan in binding loop position 7 best enhanced Tb3+ luminescence in the oncomodulin mutant Y57W, as well as VU-9 (F99W) and VU-32 (T26W) calmodulin. Excitation spectra of Y57F, F102W, Y65W oncomodulin, and Cod III parvalbumin revealed that the principal Tb3+ luminescence donor residues were phenylalanine or tyrosine located in position 7 of a loop, despite the presence of other nearby donors, including tryptophan. Spectra also revealed conformational differences between the Ca2+- and Tb(3+)-bound forms. An alternate binding loop, based on Tb3+ binding to model peptides, was inserted into the CD loop of oncomodulin by cassette mutagenesis. The order of fill of Tb3+ in this protein reversed, with the mutated loop binding Tb3+ first. This indicates a much higher affinity for the consensus-based mutant loop. The mutant loop inserted into oncomodulin had 32 times more Tb3+ luminescence than the identical synthetic peptide, despite having the same donor tryptophan and metal binding ligands. In this paper, a ranking of sensitivity of luminescence of bound Tb3+ is made among this subset of calcium binding proteins. This ranking is interpreted in light of the structural differences affecting Tb3+ luminescence enhancement intensity. The mechanism of energy transfer from an aromatic amino acid to Tb3+ is consistent with a short-range process involving the donor triplet state as described by Dexter (Dexter, D. L. (1953) J. Chem. Phys. 21, 836). This cautions against the use of the Forster equation in approximating distances in these systems

Referral and collaboration between South African psychiatrists and religious or spiritual advisers: Views from some psychiatrists

Background. Referral between psychiatrists and spiritual workers (e.g. Christian pastoral care workers, traditional healers, imams, rabbis and others) in the heterogeneous South African (SA) society is complicated and requires investigation to establish appropriate norms.  Objective. To capture the views of some local psychiatrists on referral and collaboration between SA psychiatrists and religious or spiritual advisers.  Methods. This explorative qualitative study involved indepth, semistructured interviews with 13 local academic psychiatrists selected through purposive sampling. Each participant had a single interview with the aim of exploring themes related to the referral and collabora­tion process between psychiatrists and spiritual advisers. Theme content analysis of interview transcripts was done. Results for one of the six identified themes are reported; other results are reported elsewhere.  Results. Within the theme ‘referral and collaboration between psychiatrists and spiritual professionals’, three subthemes were identified: facilitating appropriate referral and intervention for individual users; information sharing and mutual awareness between disciplines; and addressing stigmatisation of users with psychiatric conditions. Conclusion. Dialogue between psychiatrists and religious or spiritual advisers should be developed on an individual practitioner and facility basis, as well as on an organised basis between representative societies. The process of formalising a relationship between local psychiatrists and different spiritual workers may, however, still have some way to go

Terbium luminescence in synthetic peptide loops from calcium-binding proteins with different energy donors.

Fourteen 14-mer peptides corresponding to a consensus sequence of metal-binding loops from proteins of the calmodulin family were synthesized. The effect of varying both the position in the binding loop, and the type of aromatic side chains as energy donors for enhancement of terbium luminescence, was studied. It was concluded that tryptophan in loop position 7 gave optimal luminescence enhancement, and that the additional inclusion of a tyrosine in the loop at positions 2 or 4 could further boost emission from the bound terbium. In all further cases energy transfer from aromatic residues at positions other than 7 was markedly less efficient. These results suggest that the peptides assume a configuration which allows a hexadentate ligand structure around the bound terbium ion. This is consistent with a Dexter-type electron exchange model of energy transfer

Sub-specialties in psychiatry: Towards parity in mental health training and services

Neuropsychiatric disorders account for 5 of the 10 most disabling medical disorders worldwide,1 and for a particularly large component of the burden of disease in South Africa.2 Unfortunately, as elsewhere, training and services in psychiatry have lagged behind those of other major disciplines, and much additional work is needed to achieve parity. We focus in particular on the status of psychiatric sub-specialties in South Africa, considering the pros and cons of their recognition in a developing country

NetKet 3: Machine Learning Toolbox for Many-Body Quantum Systems

We introduce version 3 of NetKet, the machine learning toolbox for many-body quantum physics. NetKet is built around neural-network quantum states and provides efficient algorithms for their evaluation and optimization. This new version is built on top of JAX, a differentiable programming and accelerated linear algebra framework for the Python programming language. The most significant new feature is the possibility to define arbitrary neural network ansätze in pure Python code using the concise notation of machine-learning frameworks, which allows for just-in-time compilation as well as the implicit generation of gradients thanks to automatic differentiation. NetKet 3 also comes with support for GPU and TPU accelerators, advanced support for discrete symmetry groups, chunking to scale up to thousands of degrees of freedom, drivers for quantum dynamics applications, and improved modularity, allowing users to use only parts of the toolbox as a foundation for their own code

Extracorporeal liver assist device to exchange albumin and remove endotoxin in acute liver failure: Results of a pivotal pre-clinical study

Background & AimsIn acute liver failure, severity of liver injury and clinical progression of disease are in part consequent upon activation of the innate immune system. Endotoxaemia contributes to innate immune system activation and the detoxifying function of albumin, critical to recovery from liver injury, is irreversibly destroyed in acute liver failure. University College London-Liver Dialysis Device is a novel artificial extracorporeal liver assist device, which is used with albumin infusion, to achieve removal and replacement of dysfunctional albumin and reduction in endotoxaemia. We aimed to test the effect of this device on survival in a pig model of acetaminophen-induced acute liver failure.MethodsPigs were randomised to three groups: Acetaminophen plus University College London-Liver Dialysis Device (n=9); Acetaminophen plus Control Device (n=7); and Control plus Control Device (n=4). Device treatment was initiated two h after onset of irreversible acute liver failure.ResultsThe Liver Dialysis Device resulted in 67% reduced risk of death in acetaminophen-induced acute liver failure compared to Control Device (hazard ratio=0.33, p=0.0439). This was associated with 27% decrease in circulating irreversibly oxidised human non-mercaptalbumin-2 throughout treatment (p=0.046); 54% reduction in overall severity of endotoxaemia (p=0.024); delay in development of vasoplegia and acute lung injury; and delay in systemic activation of the TLR4 signalling pathway. Liver Dialysis Device-associated adverse clinical effects were not seen.ConclusionsThe survival benefit and lack of adverse effects would support clinical trials of University College London-Liver Dialysis Device in acute liver failure patients

The South African Society of Psychiatrists (SASOP) treatment guidelines for psychiatric disorders

The South African Society of Psychiatrists (SASOP) Treatment Guidelines for Psychiatric Disorders have been developed in order to address the local need for guidelines in our unique clinical setting. The need for treatment guidelines has frequently been expressed by South African psychiatrists and other medical practitioners, as well as by other role players such as medical scheme and other funding body advisors and the pharmaceutical industry. While several well-developed international treatment guidelines are readily accessible and are indeed extensively utilised in South Africa, they are not always applicable to our own circumstances. There are often important differences, not only regarding the availability of various psychotropic medications, but also in healthcare settings and availability of resources that need to be considered when selecting particular medications. For example, prescribing compounds that require regular monitoring such as lithium and clozapine may not always be feasible in certain rural settings in South Africa.http://www.sajp.org.za/index.php/sajpam201