Screening donors for xenotransplantation: The potential for xenozoonoses

Xenotransplantation is a potential solution to the current donor shortage for solid organ transplantation. The transmission of infectious agents from donor organs or bone marrow to the recipient is a well-recognized phenomenon following allotransplantation. Thus the prospect of xenotransplantation raises the issue of xenozoonoses-i.e., the transmission of animal infections to the human host. Anticipating an increasing number of baboon to human transplants, 31 adult male baboons (Papio cynocephalus) from a single colony in the United States were screened for the presence of antibody to microbial agents (principally viral) that may pose a significant risk of infection. Antibody to simian cytomegalovirus, simian agent 8 and Epstein-Barr virus, was found in 97% of animals tested. Antibody to simian retroviruses and Toxoplasma gondii was found in 30% and 32% respectively. Discordant results were found when paired samples were examined by two primate laboratories. This was particularly noted when methodologies were based on cross-reaction with human viral antigens. These results highlight the need to develop specific antibody tests against the species used for xenotransplantation. © 1994 Williams & Wilkins

Liver Allograft: Its Use in Chronic Active Hepatitis with Macronodular Cirrhosis, Hepatitis B Surface Antigen

A patient suffering from chronic active hepatitis with macronodular cirrhosis, positive for hepatitis B surface antigen (HBsAg), was treated with an orthotopic liver allograft. The HBs antigenemia, as measured with several precipitation tests and by complement fixation, became negative after transplantation and remained so for about 2½ months. During the interval, very low titers of the antigen were detectable by radioimmunoassay. At about three months after transplantation, she had an attack of acute hepatitis, at which time HBsAg became detectable by all tests. She recovered, but progressive liver disease developed during the remaining 1½ years of her life. She died of disseminated nocardiosis and candidiasis with deteriorating hepatic function. The homograft at autopsy showed no evidence of rejection, but was the site of chronic active liver disease, although of a different pathologic pattern than that affecting her native liver. The differences in histology may reflect the influence of chronic immunosuppression on the features of chronic active hepatitis. © 1979, American Medical Association. All rights reserved

Older adults who have previously fallen due to a trip walk differently than those who have fallen due to a slip

Studying the relationships between centre of mass (COM) and centre of pressure (COP) during walking has been shown to be useful in determining movement stability. The aim of the current study was to compare COM–COP separation measures during walking between groups of older adults with no history of falling, and a history of falling due to tripping or slipping. Any differences between individuals who have fallen due to a slip and those who have fallen due to a trip in measures of dynamic balance could potentially indicate differences in the mechanisms responsible for falls. Forty older adults were allocated into groups based on their self-reported fall history during walking. The non-faller group had not experienced a fall in at least the previous year. Participants who had experienced a fall were split into two groups based on whether a trip or slip resulted in the fall(s). A Vicon system was used to collect full body kinematic trajectories. Two force platforms were used to measure ground reaction forces. The COM was significantly further ahead of the COP at heel strike for the trip (14.3 ± 2.7 cm) and slip (15.3 ± 1.1 cm) groups compared to the non-fallers (12.0 ± 2.7 cm). COM was significantly further behind the COP at foot flat for the slip group (−14.9 ± 3.6 cm) compared to the non-fallers (−10.3 ± 3.9 cm). At mid-swing, the COM of the trip group was ahead of the COP (0.9 ± 1.6 cm), whereas for the slip group the COM was behind the COP (−1.2 ± 2.2 cm). These results show identifiable differences in dynamic balance control of walking between older adults with a history of tripping or slipping and non-fallers

Liver replacement for alpha<inf>1</inf>-antitrypsin deficiency

A 16-year-old girl with advanced cirrhosis and severe alpha1-antitrypsin deficiency of the homozygous PiZZ phenotype was treated by orthotopic liver transplantation. After replacement of the liver with a homograft from a donor with the normal PiMM phenotype, the alpha1-antitrypsin concentration in the recipient's serum rose to normal; it had the PiMM phenotype. Two and a third years later, chronic rejection necessitated retransplantation. Insertion of a homograft from a heterozygous PiMZ donor was followed by the identification of that phenotype in the recipient's serum. Neither liver graft developed the alpha1-antitrypsin glycoprotein deposits seen with the deficiency state. These observations confirm that this hepatic-based inborn error of metabolism is metabolically cured by liver replacement. © 1977

Left ventricular hypertrophy and incident cognitive decline in older adults with hypertension

The association between raised blood pressure and increased risk of subsequent cognitive decline is well known. Left ventricular hypertrophy (LVH), as a marker of hypertensive target organ damage, may help identify those at risk of cognitive decline. We assessed whether LVH was associated with subsequent cognitive decline or dementia in hypertensive participants aged ≥80 years in the randomized, placebo-controlled Hypertension in the Very Elderly Trial. LVH was assessed using 12-lead electrocardiography (ECG) based on the Cornell Product (CP-LVH), Sokolow-Lyon (SL-LVH), and Cornell Voltage (CV-LVH) criteria. The Mini-Mental State Examination (MMSE) was used to assess cognitive function at baseline and annually. A fall in MMSE to 3 points were defined as cognitive decline and triggered dementia screening (Diagnostic Statistical Manual IV). Death was defined as a competing event. Fine-Gray regression models were used to examine the relationship between baseline LVH and cognitive outcomes. There were 2645 in the analytical sample, including 201 (7.6%) with CP-LVH, 225 (8.5%) SL-LVH and 251 (9.5%) CV-LVH. CP-LVH was associated with increased risk of cognitive decline, subdistribution hazard ratio (sHR)1.3 (95% confidence interval (CI) 1.01–1.67) in multivariate analyses. SL-LVH and CV-LVH were not associated with cognitive decline (sHR1.06 (95% CI 0.82–1.37) and sHR1.13 (95% CI 0.89–1.43), respectively). LVH was not associated with dementia. LVH may be related to subsequent cognitive decline, but evidence was inconsistent depending on ECG criterion and there were no associations with incident dementia. Additional work is needed to understand the relationships between blood pressure, LVH assessment and cognition

Left atrial enhancement correlates with myocardial conduction velocity in patients with persistent atrial fibrillation

Background: Conduction velocity (CV) heterogeneity and myocardial fibrosis both promote re-entry, but the relationship between fibrosis as determined by left atrial (LA) late-gadolinium enhanced cardiac magnetic resonance imaging (LGE-CMRI) and CV remains uncertain. Objective: Although average CV has been shown to correlate with regional LGE-CMRI in patients with persistent AF, we test the hypothesis that a localized relationship exists to underpin LGE-CMRI as a minimally invasive tool to map myocardial conduction properties for risk stratification and treatment guidance. Method: 3D LA electroanatomic maps during LA pacing were acquired from eight patients with persistent AF following electrical cardioversion. Local CVs were computed using triads of concurrently acquired electrograms and were co-registered to allow correlation with LA wall intensities obtained from LGE-CMRI, quantified using normalized intensity (NI) and image intensity ratio (IIR). Association was evaluated using multilevel linear regression. Results: An association between CV and LGE-CMRI intensity was observed at scales comparable to the size of a mapping electrode: −0.11 m/s per unit increase in NI (P < 0.001) and −0.96 m/s per unit increase in IIR (P < 0.001). The magnitude of this change decreased with larger measurement area. Reproducibility of the association was observed with NI, but not with IIR. Conclusion: At clinically relevant spatial scales, comparable to area of a mapping catheter electrode, LGE-CMRI correlates with CV. Measurement scale is important in accurately quantifying the association of CV and LGE-CMRI intensity. Importantly, NI, but not IIR, accounts for changes in the dynamic range of CMRI and enables quantitative reproducibility of the association

Are food allergic consumers ready for informative precautionary allergen labelling?

Abstract Precautionary allergen labelling (PAL) has resulted in consumer confusion. Previous research has shown that interpretive labels (using graphics, symbols, or colours) are better understood than the traditional forms of labels. In this study, we aimed to understand if consumers would use interpretive labels (symbol, mobile phone application and a toll-free number) with or without medical advice that was advocated by the food industry rather than the normal PAL. This is relevant information for industry and clinicians as it provides an insight into the food allergic perception regarding PAL