The BRAF and NRAS mutation prevalence in dermoscopic subtypes of acquired naevi reveals constitutive mitogen-activated protein kinase pathway activation.

BACKGROUND: Acquired naevi can have unique dermoscopic patterns that correspond to distinct microanatomical growth patterns. Previous studies on acquired naevi stratified according to dermoscopic pattern focused on the frequency of somatic BRAF mutations, whereas NRAS mutations remained to be elucidated. OBJECTIVES: To investigate the BRAF and NRAS mutation prevalence and activation of the mitogen-activated protein kinase (MAPK) pathway in distinct dermoscopic subtypes of acquired naevi. METHODS: Common mutations present in BRAF and NRAS were assessed in 40 globular, reticular and peripheral rim of globules (PG) subtypes of acquired naevi from 27 participants (19 male, 8 female; mean age 46·7 years) selected from 1261 eligible volunteers. Mutations were determined using the highly sensitive and quantitative QX200 droplet digital™ polymerase chain reaction (ddPCR) system. RESULTS: The BRAF V600E (c.1799T>A or c.1799_1800delTGinsA) and BRAF V600K mutations were detected in 85% (n = 34/40) of naevi. All BRAF wild-type naevi (15%; n = 6/40) harboured an NRAS codon 12/13 or 61 mutation. BRAF mutations were present in 92% (n = 12/13) of globular and 100% (n = 12/12) of PG naevi, whereas reticular naevi were 67% (n = 10/15) BRAF- and 33% (n = 5/15) NRAS-mutant (P = 0·037). CONCLUSIONS: We discovered that 100% of the assessed acquired naevi had either a BRAF or NRAS mutation. Using sensitive techniques capable of single-cell mutation detection, it is likely that all acquired naevi will be mutated for BRAF or NRAS. Because both of these mutations are prevalent in distinct dermoscopic naevus subsets, our study supports the role of the MAPK pathway in the development of benign melanocytic proliferations, indicating that additional genomic events besides somatic mutations in BRAF or NRAS are required for melanoma development.

Histopathology and reflectance confocal microscopy features of photodamaged skin and actinic keratosis.

BACKGROUND: Actinic keratosis (AK) usually co-exists in areas of severe photodamage, but the clinical applicability of reflectance confocal microscopy (RCM) in diagnosing AK currently depends on a set of parameters yet to be defined in comparison to photodamaged skin (PD). OBJECTIVE: To correlate the RCM features of PD and AK with histopathology. METHODS: Twenty participants with a mean age of 64 years and skin phototype I and II were studied. RCM was performed on two PD and one AK within a field of 25 cm2 on the left dorsal forearm, followed by shave biopsies. Blinded evaluation of the histopathological and RCM images using established parameters in AK were performed retrospectively in consensus with an expert confocalist, correlated with the histopathological diagnosis by a board-certified dermatopathologist. RESULTS: A total of 57/60 areas were included. There were 43/57 (75%) and 14/57 (25%) histopathologically confirmed PD and AK respectively. Individual corneocytes, stratum corneum disruption, dermal inflammatory cells, increased vascularity/dilated vessels and solar elastosis were detected in PD and AK upon histopathology and RCM. The features in favour of AK were parakeratosis, hyperkeratosis, more severe keratinocyte pleomorphism and architectural disruption, and the presence of epidermal inflammatory cells. PD also demonstrated keratinocyte pleomorphism and architectural disruption though this was generally less severe than AK. A small subset of PD exhibited a comparable degree of keratinocyte pleomorphism and architectural disruption to the AKs in the cohort. CONCLUSIONS: The viable epidermis demonstrates PD and AK to be part of a disease continuum corresponding to field cancerization. Individual corneocytes, stratum corneum disruption, dermal inflammatory cells, increased vascularity/dilated vessels and solar elastosis may be present in PD; whereas, parakeratosis and hyperkeratosis may represent the key to distinguishing AK from PD using RCM. The significance of epidermal inflammatory cells in the RCM diagnosis of AK remains to be elucidated.

How spirituality is understood and taught in New Zealand medical schools.

OBJECTIVES: The objective of this research was to explore how spirituality is currently understood and taught in New Zealand Medical Schools. METHODS: A mixed methods study was carried out involving interviews (n = 14) and a survey (n = 73). The first stage of the study involved recorded semi-structured interviews of people involved in curriculum development from the Dunedin School of Medicine (n = 14); which then informed a cross-sectional self-reported electronic survey (n = 73). RESULTS: The results indicate that spirituality is regarded by many involved in medical education in New Zealand as an important part of healthcare that may be taught in medical schools, but also that there is little consensus among this group as to what the topic is about. SIGNIFICANCE OF RESULTS: These findings provide a basis for further discussion about including spirituality in medical curricula, and in particular indicate a need to develop a shared understanding of what 'spirituality' means and how it can be taught appropriately. As a highly secular country, these New Zealand findings are significant for medical education in other secular Western countries. Addressing spirituality with patients has been shown to positively impact a range of health outcomes, but how spirituality is taught in medical schools is still developing across the globe.

A potent Chk1 inhibitor is selectively cytotoxic in melanomas with high levels of replicative stress.

There are few effective treatments for metastatic melanoma. Checkpoint kinase 1 (Chk1) inhibitors are being trialled for their efficacy in enhancing conventional chemotherapeutic agents, but their effectiveness as single agents is not known. We have examined the effectiveness of two novel Chk1 selective inhibitors, AR323 and AR678, in a panel of melanoma cell lines and normal cell types. We demonstrate that these drugs display single-agent activity, with IC50s in the low nanomolar range. The drugs produce cytotoxic effects in cell lines that are most sensitive to these drugs, whereas normal cells are only sensitive to these drugs at the higher concentrations where they have cytostatic activity. The cytotoxic effect is the consequence of inhibition of S-phase Chk1, which drives cells prematurely from late S phase into an aberrant mitosis and results in either failure of cytokinesis or cell death through an apoptotic mechanism. The sensitivity to the Chk1 inhibitors was correlated with the level of endogenous DNA damage indicating replicative stress. Chk1 inhibitors are viable single-agent therapies that target melanoma cells with high levels of endogenous DNA damage. This sensitivity suggests that Chk1 is a critical component of an adaptation to replicative stress in these cells. It also suggests that markers of DNA damage may be useful in identifying the melanomas and potentially other tumour types that are more likely to be sensitive to Chk1 inhibitors as single agents.

Multinucleate epithelial change in colorectal hyperplastic polyps: a review of 27 cases.

AIM: To document the histological features of multinucleated epithelial giant cells (MEGs) in colorectal hyperplastic polyps and determine a possible aetiological agent. METHODS: Hyperplastic polyps were assessed for MEGs during the routine reporting at a private laboratory and public hospital laboratory. The histological features and clinical data were assessed, and immunohistochemical stains were performed to assess for viral infection (cytomegalovirus (CMV) and herpes simplex virus (HSV) 1 and 2) and to assist in the assessment of dysplasia (Ki-67, beta-catenin and p53). Ultrastructural examination was performed in one case. RESULTS: MEGs were identified in 27 polyps (24 patients). There was active inflammation in the polyps in nearly all cases (n = 24) and most showed changes in adjacent non-hyperplastic bowel mucosa such as focal basal cryptitis and apoptosis of crypt epithelium (16 patients). Immunohistochemistry for CMV, HSV and p53 was negative in all cases. The MEGs showed nuclear positivity for the proliferative marker Ki-67 and membranous positivity for beta-catenin. Ultrastructural studies failed to reveal viral particles. CONCLUSIONS: All the polyps containing MEGs showed active inflammation and apoptosis, and in most there was also focal inflammation and apoptosis in the adjacent mucosa. Inflammation in conjunction with the increased epithelial proliferation characteristics of hyperplastic polyps could be the mechanism for the MEG formation. In this series, all the polyps were associated with sodium phosphate bowel preparation (NaP) and the pro-inflammatory properties of NaP may be a stimulus for the induction of giant cells.

Macroscopic vascular invasion in synovial sarcoma evident on MRI.

We present a case of recurrent synovial sarcoma in the soft tissues of the calf, where MR imaging not only confirmed the diagnosis of tumour recurrence, but also demonstrated direct venous invasion and tumour thrombus within the popliteal vein and its tributaries. Venous invasion has particular relevance to synovial sarcoma prognostication and should be actively sought on MR imaging. To our knowledge this is the first reported case in the English literature of histologically proven macroscopic popliteal vein invasion from a synovial sarcoma demonstrated on MR imaging.

Respiratory responsiveness in male alcoholics after withdrawal.

Peripheral and central chemosensitivity were assessed in eight abstinent male alcoholic patients and in seven healthy normal male subjects. Hypoxic rebreathing (15% O2, 7% CO2) was used to stimulate the peripheral and central chemoreceptors together. Hyperoxic rebreathing (93% O2, 7% CO2) was used to examine the central chemoreceptor response independently of the peripheral chemoreceptors. Minute ventilation was examined in relation to end-tidal PACO2 under the two conditions. Neither peripheral nor central chemoreceptor responses were significantly altered in the alcoholic as compared to the control subjects. Abnormal chemoreceptor function is therefore unlikely to be an important factor in the development of abnormal respiratory events during sleep in abstinent alcoholic subjects.

Effects of ethanol ingestion on blood pressure reactivity.

We examined the acute effects of ethanol consumption on circulatory responses to the cold pressor test, to handgrip exercise and to intravenous infusion of methoxamine in eight normal male subjects. Ethanol consumption reduced systolic blood pressure responses to the cold pressor test and to handgrip exercise and depressed both systolic and diastolic blood pressure responses to infusion of methoxamine. The depressant effects of ethanol on blood pressure responses to methoxamine were considerably greater than the effects on the cold pressor test and handgrip exercise. Catecholamine concentrations during the cold pressor test and handgrip exercise were not significantly different with or without prior ethanol consumption. Alcohol has been shown to have an acute hypotensive action with all the stimuli.

The effects of acute and chronic ingestion of ethanol on the autonomic nervous system.

Evidence is reviewed linking clinical effects of ethanol with actions on the sympathetic and parasympathetic nervous systems. The studies reported include a series of investigations by the authors. Acutely, ethanol causes peripheral vasodilation and may also result in changes in heart rate and blood pressure. Ethanol may contribute to acute problems which may present clinically, including micturition syncope, accidental hypothermia and facial flushing. However, increased sympathetic nervous activity plays a role in causing hypertension and other symptoms during ethanol withdrawal in chronic alcoholics. Some chronic alcoholics may have neuropathy involving sympathetic nerves, and this can result in distal sweating loss and occasionally in orthostatic hypotension. Also, hypothalamic lesions associated with Wernicke's encephalopathy may result in hypothermia. Neuropathy involving parasympathetic nerves in not uncommon in alcoholics with other evidence of nervous system damage, but it is generally asymptomatic. Occasionally, vagal neuropathy may cause disorder of gastrointestinal motility, and neuropathy affecting the sacral innervation may be a factor in alcoholic impotence.

Factors which influence the effectiveness of treatment of epilepsy.

Despite recent advances in the management of epilepsy, some patients continue to have seizures which defy therapeutic intervention. To examine factors which may influence the successful application of therapy a survey was carried out of 103 patients, with a previous diagnosis of epilepsy, who had a seizure for which an ambulance was called. It was evident that anticonvulsants are not always used to their maximum potential or under optimal conditions. Problems which were identified in treatment included the widespread use of polypharmacy. Patients contributed to failure of seizure control by lack of compliance with therapy (29 patients) and by excessive alcohol consumption (19 patients).

Comparison of mefenamic acid and propranolol with placebo in migraine prophylaxis.

The prophylactic effects of the antiprostaglandin agent mefenamic acid on migraine attacks were compared with propranolol or placebo in a double-blind crossover study of 29 patients. In the 17 patients who completed the trial the frequency of attacks and their total duration were significantly reduced during mefenamic acid therapy or propranolol therapy as compared to placebo. There were no significant effects of mefenamic acid or propranolol on average duration or severity of migraine attacks. The study suggests that mefenamic acid and propranolol are equally effective for migraine prophylaxis.

Effects of ethanol on cardiovascular and catecholamine responses to mental stress.

The purpose of this study was to examine the effects of ethanol on heart rate, blood pressure and plasma noradrenaline and adrenaline responses to mental stress, involving reactions to anxiety and excitement produced using a cognitive task with electric shock and a competitive electronic game respectively. Twenty subjects were studied, each subject acting as his own control by participating twice, with and without prior ethanol consumption. Mental stress was associated with significant increases in all variables except plasma noradrenaline during the cognitive task. Ethanol raised baseline heart rate and plasma adrenaline, but significantly reduced the responses of these variables to the cognitive task but not to the electronic game. Systolic blood pressure responses to both experimental stressors and diastolic blood pressure responses to the electronic game were also significantly reduced after ethanol. These results may reflect a tension-reducing effect of ethanol in situations associated with anxiety, but suggest a more general effect of ethanol on blood pressure reactivity.

Sleep apnoea in alcoholic patients after withdrawal.

Respiration during sleep was studied in 16 withdrawn alcoholic patients and in 12 control subjects. The alcoholic patients had increased numbers of central (P less than 0.01) and of obstructive (P less than 0.05) apnoea and of hypopnoea episodes (P less than 0.01) as compared with controls. Significant positive associations were found between the frequencies of central apnoea (P less than 0.05) or hypopnoea (P less than 0.01) and clinical evidence of central nervous system damage in the alcoholic patients. Hypopnoea also showed a significant association with vagal neuropathy (P less than 0.05), assessed by tests of cardioreflexes. We conclude that abnormal respiratory events are common in abstinent alcoholic patients and that they are likely to be at least partly related to nervous damage.

No effect of ethanol ingestion on beta-adrenoceptor-mediated circulatory responses to isoprenaline in man.

The acute effects of ethanol on circulatory responses to isoprenaline and atropine were investigated in 21 and 15 normal male subjects respectively. Each subject acted as his own control by participating twice, once after consumption of ethanol (1.0 ml kg-1, 20% v/v in orange juice) and once after orange juice. Ethanol increased baseline heart rate and forearm blood flow, but had no effect on heart rate and forearm blood flow responses to isoprenaline, or on heart rate responses to atropine. Baseline blood pressure and blood pressure responses to isoprenaline were also unaffected by ethanol. It is concluded that acute ethanol ingestion has no physiologically significant effect on beta-adrenoceptor responsiveness as assessed by the cardiovascular responses to bolus doses of isoprenaline.

No improvement in ethanol-induced memory deficits after administration of a vasopressin analog.

Acute ingestion of ethanol impairs memory, an effect which might be related to ethanol-induced inhibition of vasopressin release. This was studied using tests of memory and cognitive function in 26 normal subjects before and after ethanol ingestion. Equal numbers of subjects received randomly, by double-blind intranasal administration, placebo or 1-desamino-8-D-arginine vasopressin prior to ethanol ingestion. Administration of the vasopressin analog did not reverse the ethanol-induced deficits in memory and cognitive function.

Beta-adrenoceptor responsiveness and plasma catecholamines as determinants of cardiovascular reactivity to mental stress.

Twenty-five normotensive men were subjected to two periods of mental stress involving a cognitive task and a competitive electronic game. Plasma catecholamines, heart rate and blood pressure were measured before and during mental stress. Responsiveness to beta-adrenoceptor stimulation was also determined in each subject by measurement of heart rate responses to bolus injections of isoprenaline. Both periods of mental stress were associated with significant increases in systolic and diastolic blood pressures, heart rate and plasma adrenaline, but not plasma noradrenaline. Heart rate responses to mental stress varied widely, with increases ranging from 1 to 48 (mean +/- SD 13.5 +/- 10.6) beats/min for the cognitive task and from 2 to 49 (20.4 +/- 14.0) beats/min for the electronic game. Systolic blood pressure responses also varied widely and showed significant positive correlations with heart rate responses. Significant relationships were found between heart rate responses to both forms of mental stress and cardiac sensitivity to isoprenaline, subjects with low responsiveness to beta-adrenoceptor stimulation tending to have smaller heart rate responses to mental stress than subjects with high responsiveness to beta-adrenoceptor stimulation. Relationships were also found between plasma adrenaline responses and heart rate responses to mental stress, although these did not reach significance. Considerably improved relationships were found when heart rate responses were correlated with a single variable generated from the product of the adrenaline response and the inverse of the dose of isoprenaline required to raise heart rate by 25 beats/min. It is concluded that wide variation is shown between different individuals in responsiveness to beta-adrenoceptor stimulation and that this is an important factor in the variability between individuals in heart rate and systolic blood pressure responses to mental stress. Both catecholamines and adrenoceptor-mediated responses to catecholamines should be examined when determining the physiological basis for differences in cardiovascular reactivity to mental stress between individuals or groups.

Drugs and folate metabolism.

Folates are a group of compounds which are required in the diet and are important in DNA, amino acids and possibly also amine metabolism. The biologically active folates are in the tetrahydro form. Tetrahydrofolates are produced from unreduced dietary folates by the enzyme dihydrofolate reductase. A number of drugs such as aminopterin, methotrexate (amethopterin), pyrimethamine, trimethoprim and triamterene act as folate antagonists and produce folate deficiency by inhibiting this enzyme. With other drugs which produce low serum and tissue concentrations of folate such as anticonvulsants, antituberculosis drugs, alcohol and oral contraceptives, the mechanism of this effect is uncertain. Possible mechanism include reduced absorption, prevention of release of folate from tissue stores, altered plasma protein binding, or increased folate metabolism in the liver. Treatment with folic acid antagonists such as methotrexate readily causes megaloblastic anaemia; this can be prevented by therapy with folinic acid (5-formyltetrahydrofolate). The role of other drugs in producing megaloblastic anaemia is less certain, e.g. it occurs in less than 0.75% of patients receiving anticonvulsants. The possible neurological and psychiatric effects of folate deficiency are also uncertain. However, in patients with folate deficiency who have neuropsychiatric symptoms, neuropathy or myelopathy, and normal vitamin B12 levels, it may be of value to try therapy with folic or folinic acid.