PINK DISEASE-TEN YEARS AFTER (THE EPILOGUE)

Systematic Assessment of Research on Autism Spectrum Disorder (ASD) and Mercury Reveals Conflicts of Interest and the Need for Transparency in Autism Research

Historically, entities with a vested interest in a product that critics have suggested is harmful have consistently used research to back their claims that the product is safe. Prominent examples are: tobacco, lead, bisphenol A, and atrazine. Research literature indicates that about 80-90% of studies with industry affiliation found no harm from the product, while only about 10-20% of studies without industry affiliation found no harm. In parallel to other historical debates, recent studies examining a possible relationship between mercury (Hg) exposure and autism spectrum disorder (ASD) show a similar dichotomy. Studies sponsored and supported by industry or entities with an apparent conflict of interest have most often shown no evidence of harm or no "consistent" evidence of harm, while studies without such affiliations report positive evidence of a Hg/autism association. The potentially causal relationship between Hg exposure and ASD differs from other toxic products since there is a broad coalition of entities for whom a conflict of interest arises. These include influential governmental public health entities, the pharmaceutical industry, and even the coal burning industry. This review includes a systematic literature search of original studies on the potential relationship between Hg and ASD from 1999 to August 2015, finding that of the studies with public health and/or industry affiliation, 86% reported no relationship between Hg and ASD. However, among studies without public health and/or industry affiliation, only 21% find no relationship between Hg and ASD. The discrepancy in these results suggests a bias indicative of a conflict of interest.

Pharmacoeconomic consequences of measurement and modification of hospital drug use

Patterns of drug usage affect hospital-based delivery of healthcare in a variety of ways. Adverse reactions to drugs (ADR) precipitate some 5% of admissions and prejudice the care of some 20% of patients who are in hospital, while inadequate drug therapy prejudices outcomes and prolongs hospital stay. Conversely, appropriate application of drugs can promote recovery and increase the quality of care. Well documented examples include prevention of deep vein thrombosis and postoperative wound infections. Accordingly, optimisation of drug use represents a major quality assurance issue in addition to determining cost-efficiency of healthcare delivery. Drug utilisation review (DUR) requires all elements of the quality assurance process. In practice, therapeutically meaningful and cost-efficient exercises can only be mounted if there is knowledge of the linkage between patterns of drug use and clinical outcomes. These processes of measurement are currently rate-limiting in quality assurance. There are various ways that hospital drug usage can be measured. These range from readily available and relatively cheap quantitative methods to methods requiring the availability of expert staff. There is a sequence of methods involving increasing costs and increasing resource demands yielding increasing detail of information obtained. This sequence commences with pharmacy purchases, followed by pharmacy issues to particular clinical areas, prescription or treatment sheet survey, clinical record review, and finally the reports of trained investigators working in the clinical area. The simpler methods can provide useful information and an efficient basis for choosing and planning definitive studies. Once a category of drug use is appropriately targeted for intervention, drug use can be modified by planned intervention with improvement in clinical outcomes and reduced economic costs in many instances. The intervention strategies to modify drug usage may be classed as re-educative, persuasive, facilitative and power strategies. Other models for implementing behavioural change have been considered, including the impact of trained investigators and the use of online computer prescribing with interactive software with appropriate guidelines. The challenge is to achieve sustained change when interventions are implemented. Cost-efficient quality assurance of drug use is possible with modest resources if outcome-orientated activities are prioritised.

Testicular obstruction: clinicopathological studies

Genital tract reconstruction has been attempted in subfertile men with obstructive azoospermia (370 patients) or unilateral testicular obstruction (80 patients), and in vasectomised men undergoing reversal for the first (130 patients) or subsequent (32 patients) time. Histopathological changes in the obstructed testes and epididymes, and immunological responses to the sequestered spermatozoa have been studied to gain insight into possible causes of failure of surgical treatment. The results of surgery have been assessed by follow-up sperm counts and occurrence of pregnancies in the female partners. The best results were obtained with vasectomy reversal (patency 90%, pregnancy 45%), even after failed previous attempts (patency 87%, pregnancy 37%). Epididymovasostomy gave good results with postinfective caudal blocks (patency 52%, pregnancy 38%), while postinfective vasal blocks were better corrected by total anatomical reconstruction (patency 73%, pregnancy 27%) than by transvasovasostomy (patency 9%, no pregnancies). Poor results were obtained with capital blocks (patency 12%, pregnancy 3%), in which substantial lipid accumulation was demonstrated in the ductuli efferentes; three-quarters of these patients had sinusitis, bronchitis or bronchiectasis (Young's syndrome). There is circumstantial evidence to suggest that this syndrome may be a late complication of mercury intoxication in childhood. After successful reconstruction, fertility was relatively reduced in those men who had antibodies to spermatozoa, particularly amongst the postinfective cases. Similarly, impaired fertility was found in men with unilateral testicular obstruction and antibodies to spermatozoa. Mononuclear cell infiltration of seminiferous tubules and rete testis was noted occasionally, supporting a diagnosis of autoimmune orchitis; although rare, this was an important observation as the sperm output became normal with adjuvant prednisolone therapy.

Mercury as a health hazard

Pink disease has virtually disappeared since teething powders were withdrawn. We describe a case in a boy who was exposed to metallic mercury vapour. We discuss the potential health hazard of spilled elemental mercury in the house and the difficulties of removing it from the environment.