An analysis of iris pattern as a risk factor for skin cancer development in immunosuppressed renal transplant recipients

INTRODUCTION

Renal transplant recipients are at increased risk of keratinocyte skin cancers with a tendency to have multiple, aggressive and difficult to treat tumours. The eye and the skin share the same embryological ectoderm. Iris pattern has recently been reported as a predictive risk factor for skin cancer in non-immunosuppressed Southern European (Grigore et al., J Eur Acad Dermatol Venereol, 2018, 1662) and Irish populations (Ridge et al., J Eur Acad Dermatol Venereol, 2022, e542).

AIMS

To analyse if an individual's iris pattern is an independent risk factor for the development of keratinocyte skin cancers in renal transplant recipients.

METHODS

Iris patterns of 110 renal transplant recipients were evaluated using the Simionescu visual three-step technique (iris periphery, colarette and iris freckling [Simionescu et al., Ann Res Rev Biol, 2014, 2525]). Established risk factors for skin cancer in transplant patients were recorded as confounding factors.

RESULTS

Observational cross-sectional study including 110 renal transplant population. Thirty-one participants had skin cancer. In the skin cancer group, iris periphery was blue/grey in 74.3% (p = 0.053, OR 2.5), the colarette was light brown in 57.1% (p < 0.0043) and iris freckles were present in 55%(p = 0.044). Dark brown and blue colarettes were observed in controls. Binary Logistic Regression analysis showed light brown colarette is a significant independent risk factor for skin cancer (OR 4.54, p < 0.02, CI 1.56-10.57).

CONCLUSION

Within this renal transplant population a blue iris periphery, light brown colarette and presence of freckling confers an independent risk for keratinocyte skin cancer. Iris pattern is a useful tool for identification of transplant patients at risk of keratinocyte skin cancer and an easy-to-use technique for risk evaluation in this cohort. This is the first study looking at iris pattern and keratinocyte skin cancer risk in renal transplant population.

β-Adrenoceptors and synaptic plasticity in the perirhinal cortex

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Bath application of isoprenaline induces LTP in the perirhinal cortex.

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LTP at amygdala to perirhinal synapses requires β1- but not β2-ADRs.

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Combination of β1-ADRs, NMDARs, and VGCC required for LTP.

Experiences with a high degree of emotional salience are better remembered than events that have little emotional context and the amygdala is thought to play an important role in this enhancement of memory. Visual recognition memory relies on synaptic plasticity in the perirhinal cortex but little is known about the mechanisms that may underlie emotional enhancement of this form of memory. There is good evidence that noradrenaline acting via β-adrenoceptors (β-ADRs) can enhance memory consolidation. In the present study we examine the role of β-ADRs in synaptic plasticity at the amygdala–perirhinal pathway (LA–PRh) and compare this to mechanisms of intra-perirhinal (PRh–PRh) synaptic plasticity. We demonstrate that activity-dependent PRh–PRh long-term potentiation (LTP) does not rely on β1- or β2-ADRs and that LA–PRh LTP relies on β1-ADRs but not β2-ADRs. We further demonstrate that application of the β-ADR agonist isoprenaline produces lasting PRh–PRh potentiation but only transient potentiation at the LA–PRh input. However, at the LA–PRh input, combining stimulation that is subthreshold for LTP induction with isoprenaline results in long-lasting potentiation. Isoprenaline-induced and isoprenaline plus subthreshold stimulation-induced potentiation in the PRh–PRh and LA–PRh inputs, respectively were both dependent on activation of NMDARs (N-methyl-D-aspartate receptors), voltage-gated calcium channels and PKA (protein kinase A). Understanding the mechanisms of amygdala–perirhinal cortex plasticity will allow a greater understanding of how emotionally-charged events are remembered.

Expression of P2X2 and P2X3 receptor subunits in rat carotid body afferent neurones: role in chemosensory signalling

1. Hypoxic chemotransmission in the rat carotid body (CB) is mediated in part by ATP acting on suramin-sensitive P2X purinoceptors. Here, we use RT-PCR, cloning and sequencing techniques to show P2X2 and P2X3 receptor expression in petrosal neurones, some of which develop functional chemosensory units with CB receptor clusters in co-culture. 2. Single-cell RT-PCR revealed that hypoxia-responsive neurones, identified electrophysiologically in co-culture, expressed both P2X2 and P2X3 mRNA. 3. Isohydric hypercapnia (10 % CO(2); pH 7.4) caused excitation of chemosensory units in co-culture. This excitation depended on chemical transmission, with ATP acting as a co-transmitter, since it was inhibited by reduction of the extracellular Ca(2+):Mg(2+) ratio and by the purinoceptor blocker suramin (50-100 microM). 4. Hypoxia and isohydric hypercapnia could separately excite the same chemosensory unit, and together the two stimuli interacted synergistically. 5. Using confocal immunofluorescence, co-localization of P2X2 and P2X3 protein was demonstrated in many petrosal somas and CB afferent terminals in situ. Taken together, these data indicate that ATP and P2X2-P2X3 purinoceptors play important roles in the peripheral control of respiration by carotid body chemoreceptors.

Gossip: does it play a role in the socialization of nurses?

Despite its generally negative reputation, gossip continues to be a significant genre of communication in every society. The initial purpose of this paper is to scrutinize gossip from historical, analytical and feminist perspectives. An extensive review of the literature suggests gossip serves three primary functions: information, influence or social control and entertainment. The second purpose is to explore how the functions of gossip may contribute to the socialization of nurses to their professional role and to their work culture.

Mineralogical studies of human urinary calculi from Natal

Knowledge of the composition of human urinary calculi within a geographical area can lead to an understanding of the epidemiology of renal stone disease. Studies in the Durban area, with its high incidence of kidney and bladder stones, indicate that calcium oxalate is the overwhelmingly dominant (circa 80%) component, followed by uric acid. An important feature is the low occurrence of phosphate stones, especially those containing struvite.

Acute epiglottitis in the adult

GPs are often the first to see adults with acute epiglottitis, yet the information on how to treat them is not usually available. The seven cases presented here demonstrate a wide spectrum of severity with characteristic signs and symptoms. Diagnosis and management are discussed.

Composition of urinary calculi collected in the Durban area

Three hundred urinary calculi were collected in the Durban area during the period August 1979--August 1980. Analysis by the X-ray diffraction method showed that their composition is generally similar to that found in the USA and UK. The incidence of uric acid, present in 17% of the calculi, is higher than that found overseas. There is a significantly higher incidence of calcium oxalate in calculi from Indians (83% v. 70% in Whites) while there is a significantly higher incidence of urinary apatite in Whites (35% v. 21% in Indians).