Smell, taste and food habits changes along body mass index increase: an observational study.

PURPOSE: To evaluate the changes in gustatory and olfactory sensitivity and dietary habits between healthy lean subjects (LS) and participants affected by overweight (OW), stage I and II obesity and to estimate possible impact of these factors on body mass index (BMI). METHODS: After a general and ear-nose-throat evaluation, taste and olfactory function testing by means of taste strips and sniffin' stick tests, respectively, and food habits analysis by means of food frequency questionnaire (FFQ), 221 participants (68 LS [33 female; mean age = 53.01 ± 7.54 years]; 51 OW [26 female; mean age = 51.5 ± 12.16 years]; 50 stage I obesity [24 female; mean age = 50.78 ± 13.71 years] and 52 stage II obesity [24 female; mean age = 52.21 ± 13.35 years]) were enrolled in the study. RESULTS: Significant (p < 0.008) reductions in total and subtest taste and smell scores were found in stage I and II obesity when compared to LS and OW participants. FFQ depicted a progressive intake increase of nutrients along the BMI stages. Significant associations were found between BMI and taste/smell subtests sugar taste carbs, saturated, monounsaturated and polyunsaturated fatty acids. CONCLUSIONS: These data demonstrated for the first time a parallel impairment in smell and taste in a large sample size of participants from lean to stage II obesity and could reinforce those previous theories claiming that the greater the ability in taste or smell qualities perception, the lower the preference for them, resulting in a lower intake of specific foods.

Onset and resolution failure of recurrent benign paroxysmal positional vertigo: the role of cervical range of motion.

PURPOSE: To explore possible associations between cervical spine mobility, measured by cervical range of motion (CROM) and a possible earlier onset of recurrent benign paroxysmal positional vertigo (BPPV), as well as an increased failure rate of canalith repositioning procedures. METHODS: Medical records of 749 patients (247, 253 and 249 patients with a CROM ≤ 45°, between 45.1° and 55° and > 55.1°, respectively) with a first-time diagnosis of non-traumatic BPPV were included in this retrospective study. Age, gender, canal involvement and CROM values were treated as prospective prognostic factors for time of BPPV recurrence onset (RO) and number of manoeuvres needed to achieve resolution (resolution rate, RR). A multiple regression analysis was performed. RESULTS: A significant increase in the incidence of recurrent BPPV was found in patients with reduced CROM (139 [56.27%;], 102 [40.31%] and 87 [34.93%], respectively, belonging to ≤ 45°, 45.1°-55° and > 55.1° subgroups; X2 = 9.42, p = 0.008). A strong association between age, CROM and recurrent BPPV RO and RR was demonstrated, respectively (multiple correlation coefficients = 0.492678 and 0.593493, respectively, p value < 10-4). Canal involvement was in line with the previous experiences. CONCLUSION: The results from this retrospective analysis unveiled the previously unexplored relation between reduction in cervical spine mobility and BPPV recurrence and treatment failure. The data from this study do not indicate the mechanisms by which this comorbidity might directly cause recurrent BPPV. However, they may suggest CROM to be evaluated, in association with other known risk factors for increased susceptibility to BPPV recurrence.

Postural and clinical outcomes of sustained natural apophyseal glides treatment in cervicogenic dizziness patients: A randomised controlled trial.

OBJECTIVE: To evaluate how self-report and posturographic measures could be affected in patients with cervicogenic dizziness undergoing sustained natural apophyseal glides. DESIGN: Randomised controlled single-blind study. SETTING: Tertiary rehabilitation centre. SUBJECTS: Patients affected by cervicogenic dizziness, diagnosed by applying accepted criteria. Forty-one patients (19 male, 22 female: mean age 44.3 ± 14.8 years) receiving treatment, and 39 patients (18 male, 21 female: mean age 43.8 ± 13.9 years) receiving placebo were included in the study. INTERVENTIONS: The treatment group underwent sustained natural apophyseal glides, while the placebo was constituted by a detuned laser. Both groups received their interventions six times over 4 weeks. MAIN MEASURES: Outcomes were tested by means of self-report measures such as perceived dizziness, neck disability, anxiety and depression. Also, cervical range of motion and posturography testing with power spectra frequency were analysed. RESULTS: When compared to placebo, treated patients demonstrated a significant decrease in perceived dizziness (post-treatment total Dizziness Handicap Inventory score 20.5 ± 5.3 as compared to 26.2 ± 6 baseline), neck disability and pain (Neck Disability Index and Neck Pain Index post-treatment scores 12.5 ± 4.3 and 45.6 ± 15.1, respectively, as compared to baseline scores of 15.1 ± 4.8 and 62.5 ± 14.3), as well as significant improvement in cervical range of motion and some posturographic parameters. CONCLUSION: Sustained natural apophyseal glides may represent a useful intervention in reaching short-term beneficial effects in patients with cervicogenic dizziness, with respect to self-perceived symptoms, proprioceptive integration and cervical range of motion improvement.

Changes in body composition in unilateral vestibular hypofunction: relationships between bioelectrical impedance analysis and neuro-otological parameters.

PURPOSE: Experimental works have indicated the potential of the vestibular system to affect body composition to be mediated by its extensive connections to brainstem nuclei involved in regulating metabolism and feeding behavior. The aim of this study was to evaluate-by means of bioelectrical impedance analysis (BIA)-the body composition in a group of chronic UVH normal-weighted patients when compared with an equally balanced group of healthy participants, serving as a control group (CG). METHODS: Forty-six chronic UVH and 60 CG participants underwent otoneurological (including video Head Impulse Test [vHIT] and static posturography testing [SPT]), BIA measurements and self-report (SRM) and performance measures (PM). RESULTS: Beyond significant (p < 0.001) changes in SPT variables (surface and length) and SRM/PM (including Dizziness Handicap Inventory, Dynamic Gait Index and Activity Balance Confidence scales), UVH participants demonstrated significant (p < 0.001) higher values of fat mass and visceral fat and lower values of muscle mass (p = 0.004), when compared to CG. Significant correlations were found in UVH participants between otoneurological and BIA measurements. CONCLUSION: These study findings represent the first clinical in-field attempt at depicting, with the use of BIA parameters, changes in body composition related to chronic UVH. Since such alterations in metabolic parameters could be considered both the consequences and/or the cause of vestibular-related quality of life deficit, BIA parameters could be considered as cheap, easy to use, noninvasive assessments in case of chronic UVH.

Reciprocal roles of joint position error, visual dependency and subjective perception in cervicogenic dizziness.

AIM: Since cervical joint position error (JPE) and visual dependency (VD) may reflect altered ascending inputs from the neck receptors, the aim of the present study was to test how these parameters may be impacted by those clinical parameters in cervicogenic dizziness (CGD) patients when compared with healthy subjects participants. MATERIALS AND METHODS: 93 subjects participants fulfilling inclusion criteria for CGD and 98 age- and gender-matched healthy subjects volunteers - undergoing cervical relocation and rod and disc test to evaluate JPE and VD, respectively - were compared to each other. Cervical range of motion (CROM), Dizziness Handicap Inventory (DHI), Neck Disability Index (NDI), Neck pain intensity (NPI), Tampa Scale for Kinesiophobia (TSK-17) and Hospital Anxiety and Depression Scale (HADS) were also collected in both groups. RESULTS: When compared to healthy participants, CGD patients were found to have a higher degree of JPE in right (p = 0.008, mean difference, MD: 2.88) and left (p = 0.006, MD: 2.55) rotation as well as in extension (p = 0.011, MD: 2.31), flexion (p = 0.009, MD: 2.35) and mean value (p = 0.001, MD: 2.53) and higher degrees of error in CCW at +40° and -40° (p = 0.012, MD: 0.85 and p = 0.016, MD: 0.82, respectively) and CW at +40° and -40° (p = 0.018, MD: 0.83 and p = 0.015 MD: 0.81, respectively). CGD patients also demonstrated a significant reduction in degrees of CROM in active flexion (p = 0.011, MD: -34.63), extension (p = 0.018, MD: -21.67), left (p = 0.012, MD: -28.29) and right (p = 0.009, MD: -28.52) rotation, and left (p = 0.02, MD: -7.29) and right (p = 0.021, MD: -5.05) lateral flexion. Furthermore, these patients demonstrated higher scores in total DHI (p = 0.007, MD: 25.17) (and relative DHI-P, DHI-F, DHI-E; p = 0.009, MD: 11.4; p = 0.014, MD: 8.73 and p = 0.018, MD: 5.03, respectively), in TSK-17 (p = 0.017, MD: 17.56), and HADS, both in anxiety (p = 0.022, MD: 4.62) and depression (p = 0.02, MD: 7.31) subscale. CONCLUSIONS: A possible common physiopathological background may impact on processes involved in both the JPE and VD behaviour, entangled in a vicious circle with the impaired subjective clinical and quality of life perception.

Postural and vestibular changes related to CPAP treatment in moderate-to-severe OSA patients: a 12-month longitudinal study.

PURPOSE: To assess whether vestibulo-ocular reflex (VOR) gain, posturography parameters and related clinical outcomes can improve in OSA patients after 12 months of CPAP treatment, taking into consideration that a certain degree of vestibular dysfunction has been identified in these subjects. METHODS: Vestibular, postural, clinical, and polygraphic parameters were assessed in 32 OSA patients before and after beneficial CPAP treatment by means of video head impulse test (vHIT), static posturography (SP), Dizziness Handicap Inventory (DHI), Epworth Sleepiness Scale (ESS), and Apnea-Hypopnea Index (AHI), respectively, and were compared by means of a "within-subject" ANOVA model and Spearman's rank correlation. RESULTS: After the 12-month period of treatment, OSA patients demonstrated a significant reduction in AHI values, in both opened and closed eyes conditions of surface and length as well as in power spectra recorded in low, middle, and high frequency interval. Although a significant improvement was also recorded among DHI and ESS scores, VOR gain increase did not survive to post-hoc corrections. Finally, positive correlations between the differences between pre- and post-treatment AHI, ESS, and PS values were found. CONCLUSIONS: The present work highlighted that postural instability and dizziness-related conditions due to OSA may improve after 12 months of CPAP treatment. Although VOR gain did not demonstrate significant improvement, this study might open future perspectives directed to assessing VOR gain changes after longer periods of CPAP treatment.

Long-term effects of vestibular rehabilitation and head-mounted gaming task procedure in unilateral vestibular hypofunction: a 12-month follow-up of a randomized controlled trial.

OBJECTIVE:: To investigate the long-term effects of adding virtual reality-based home exercises to vestibular rehabilitation in people with unilateral vestibular hypofunction. DESIGN:: Follow-up otoneurological examination in two randomized groups following a previous one-month trial. SETTING:: Tertiary rehabilitation center. SUBJECTS:: A total of 47 patients with unilateral vestibular hypofunction, one group ( n = 24) undergoing conventional vestibular rehabilitation and the other one ( n = 23) implementing, in addition, head-mounted gaming home exercises, 20 minutes per day for one month. INTERVENTIONS:: One year after completing rehabilitation, patients underwent testing with static posturography, video head impulse test, self-report questionnaires, and a performance measure. MAIN MEASURES:: Vestibulo-ocular reflex gain, posturographic parameters such as length, surface, and fast Fourier transform power spectra, self-report, and gait performance measure scores. RESULTS:: Vestibulo-ocular reflex gain was significantly better with respect to pretreatment in both groups. The mixed-method group showed significantly higher gain scores: mean (standard deviation (SD)) at 12 months was 0.71 (0.04), versus 0.64 (0.03) for the vestibular rehabilitation-only group ( P < 0.001). Accordingly, some classical posturography scores such as surface with eyes open and length with eyes closed and low-frequency power spectra were significantly different between groups, with the virtual reality group showing improvement ( P < 0.001). Self-report measures were significantly better in both groups compared to pretreatment, with significant improvement in the mixed-method group as compared to conventional rehabilitation alone: Dizziness Handicap Inventory mean total score was 24.34 (2.8) versus 35.73 (5.88) with a P-value <0.001. CONCLUSION:: Results suggest that head-mounted gaming home exercises are a viable, effective, additional measure to improve long-term vestibular rehabilitation outcomes.

Viral Metagenomics of Blood Donors and Blood-Derived Products Using Next-Generation Sequencing.

Transfusion-transmitted infections remain a permanent threat in medicine. It keeps the burden of the past, marked by serious infections transmitted by transfusion, and is constantly threatened by emerging viruses. The global rise of immunosuppression among patients undergoing frequent transfusions exacerbates this problem. Over the past decade, criteria for donor selection have become increasingly more stringent. Although routine nucleic acid testing (NAT) for virus-specific detection has become more sensitive, these safety measures are only valuable for a limited number of select viruses. The scientific approach to this is however changing, with the goal of trying to identify infectious agents in donor units as early as possible to mitigate the risk of a clinically relevant infection. To this end, and in addition to an epidemiological surveillance of the general population, researchers are adopting new methods to discover emerging infectious agents, while simultaneously screening for an extended number of viruses in donors. Next-generation sequencing (NGS) offers the opportunity to explore the entire viral landscape in blood donors, the so-called metagenomics, to investigate severe transfusion reactions of unknown etiology. In the not too distant future, one could imagine this platform being used for routine testing of donated blood products.

Olfactory-Related Quality of Life in Multiple Chemical Sensitivity: A Genetic-Acquired Factors Model.

Genetic polymorphisms as well as environmental exposures to chemical compounds, iatrogenic, psychological, and physical trauma may play a pathophysiological role in multiple chemical sensitivity (MCS) olfactory complaints, given that xenobiotic metabolism is influenced by sequence variations in genes of metabolizing enzymes. Thus, the aim of the present study was to depict-by means of multiple regression analysis-how different genetic conditions, grouped according to their function as well as clinical background and environmental exposure may interfere with those olfactory complaints referred by MCS patients. Therefore, MCS patients after gene polymorphism sequencing, the olfactory-related quality of life score-calculated by means of the Questionnaire of Olfactory Disorder in forty-six MCS patients-have been found to significantly rely on the phase I and II enzymes score and exposure to previous compounds and surgical treatments. The present work-implementing for the first time a genetic-acquired factors model on a regression analysis-further reinforces those theories, positing MCS as a complex, multifactorial, disease in which the genetic risk related to phase I and II enzymes involved in xenobiotic detoxification, olfactory, and neurodegenerative diseases play a necessary, but probably not sufficient role, along the pathophysiological route of the disease.

Perspectives on multisensory perception disruption in idiopathic environmental intolerance: a systematic review.

PURPOSE: Multiple chemical sensitivity (MCS) also known as idiopathic environmental intolerance/illness (IEI) encompasses a cohort of subjective symptoms characterized by susceptibility to a wide spectrum of environmental compounds, causing symptoms involving various organs and a decrease in quality of life. The aim of this systematic review is to summarize evidence about MCS, with focus on indexed studies analyzing sensory pathway-related disorders. METHODS: Medical databases were searched for English language articles related to the topic, published between 1965 and 2017 in academic, peer-reviewed journals. Particular focus was concentrated on articles depicting disturbances involving sensory organs. References of the relevant articles were examined to identify additional significant documents. RESULTS: Fifty-eight studies were eligible for full text review. Of these, 34 studies met the selection criteria and were included in this analysis. Many variables, such as different diagnostic criteria, lack of homogeneous symptom questionnaires and the general incidence of personality traits in control subjects, biased studies as confounding factors. However, moderate evidences show that sensory pathways are somewhat altered, especially with respect to information processing in the limbic system and related cortical areas. Recent studies suggested the presence, in MCS cohorts, of attention bias, sensitization and limbic kindling, as well as recently revealed subclinical organic alterations along sensory pathways. CONCLUSIONS: Evidences are consistent with MCS/IEI to be the result of a neural altered processing of sensorial ascending pathways, which combined with peculiar personality traits constitutes the underpinning of a multisensory condition needing multidisciplinary clinical approach.

Gradient impact of cognitive decline in unilateral vestibular hypofunction after rehabilitation: preliminary findings.

PURPOSE: Considering recent advances in central cognitive- and age-related processing interfering with balance and sensory reweighting in uncompensated vestibular disorders, purpose of this study is to highlight the vestibular rehabilitation (VR) outcomes in a population of older adults and age-matched mild cognitive impairment (MCI) patients, both affected by unilateral vestibular hypofunction (UVH) and undergoing VR. METHODS: Vestibulo-ocular reflex (VOR), postural sway examination (respectively, performed by video head impulse test and static posturography) and dizziness-related and quality-of-life scores were collected in 12 UVH MCI individuals ≥ 55 years and 12 matched UVH older adults with age-appropriate cognitive function-cognitively evaluated by means of Mini-Mental State Examination (MMSE) and Alzheimer's Disease Assessment Scale-before and after a VR protocol. RESULTS: A significant post-treatment reduction in surface, length and power spectra (PS) values within low-frequency domain and an improvement in performance measures were recorded in both groups. Moreover, the VR protocol highlighted-when comparing pre-/post-treatment differences (Δ)-a significant (i) increase in Δ VOR gain; (ii) decrease in Δ surface and length and (iii) increase in Δ PS within low-frequency domain in older adults when compared to MCI patients. Positive correlations were found between MMSE and Δ Dynamic Gait Index, Δ surface and Δ PS within low-frequency domain when treating patients as 'a continuum' along the cognitive decline. CONCLUSIONS: Present pilot findings suggest that the cognitive domain insight in older adults scheduled for VR protocols may positively impact on disability consequences.

Integrating postural and vestibular dimensions to depict impairment in moderate-to-severe obstructive sleep apnea syndrome patients.

Vestibular dysfunction was linked to moderate-to-severe obstructive sleep apnea syndrome (OSAS) patients in literature. However, due to a lack of knowledge among valid and recent implementations conceived to study postural control on static posturography (SP) and vestibulo-ocular reflex (VOR) gain under physiological conditions (video Head Impulse Test; vHIT), the aim of this work was to integrate (i) VOR changes via vHIT implementation, (ii) postural arrangement by studying both classical parameters and frequency spectra (PS) and (iii) correlation between these findings, polygraphic (PG) and subjective scores along Dizziness Handicap Inventory (DHI) and Epworth Sleepiness Scale (ESS). Thus, 32 moderate-to-severe OSAS patients and 32 healthy subjects - studied by using PG, DHI and ESS - underwent vHIT and SP posturographic assessment. Analysis of variance was performed to disclose between-group effects and correlation analysis was implemented between otoneurological, PG, DHI and ESS values. OSAS group demonstrated a significant decay of VOR gain and an increase in both frequency spectra PS values, especially within the low-frequency interval, and in classical posturographic SP parameters. Further, positive and negative correlations between mean SaO2 and gain and low frequency interval spectra PS were found, respectively. Strengthening previous hypothesis related to brainstem chronic hypoxemia phenomena affecting vestibular network, implementation of these data could generate future attentions (i) for screening under physiological conditions postural and vestibular detriments in OSAS subjects, especially exposed at risk settings, and (ii) among PG parameters, such as mean SaO2 , to propose further reliable tools in monitoring postural and vestibular decay in these patients demonstrating PG parameters detriments.

Noise sensitivity and hyperacusis in patients affected by multiple chemical sensitivity.

PURPOSE: The aim of this study was to investigate the presence of noise sensitivity and hyperacusis in patients suffering from multiple chemical sensitivity (MCS), a chronic condition characterized by several symptoms following low-level chemical exposure. Moreover, distortion product otoacoustic emissions (DPOAE) were performed to further study cochlear function. METHODS: A questionnaire-based survey was performed. Eighteen MCS patients, selected with strict diagnostic criteria, and 20 healthy age- and gender-matched subjects filled Weinstein's Noise Sensitivity Questionnaire (WNS) and Khalfa's Hyperacusis Questionnaire (HQ). Results were compared with scores from the quick Environmental Exposure Sensitivity Index (qEESI), a routinarily used questionnaire to screen MCS symptoms, and with DPOAE values. An analysis of variance (ANOVA) was performed between MCS and control subjects scores; moreover, Spearman's rank correlation test was performed between questionnaire results. RESULTS: ANOVA testing on DPOAE values showed any significant difference between groups, while WNS, HQ and qEESI scores were significantly higher in MCS group compared to controls. Correlation analysis showed strong positive correlation between WNS, HQ and qEESI in MCS subjects. CONCLUSIONS: For the first time, auditory-related perceptual disorders were studied in MCS. A strong association between WNS, HQ results and MCS symptoms severity has been highlighted. These findings suggest that decreased sound tolerance and noise sensitivity could be considered as possible new aspects of this syndrome, contributing to its peculiar phenotype. Furthermore, as DPOAE values did not differ from healthy subjects, present findings might suggest a 'central' source for such disorders in this group of patients.

Cerebral metabolic changes related to clinical parameters in idiopathic anosmic patients during olfactory stimulation: a pilot investigation.

Idiopathic olfactory loss neural consequences have been studied especially by means of magnetic resonance imaging. Since other functional neuroimaging technique findings are lacking in the literature, present study used a validated 18F-2-fluoro-2-deoxy-D-glucose (FDG) functional positron emission tomography procedure under olfactory stimulation (OS) to assess brain changes in idiopathic anosmic patients (IAPs) in comparison with healthy subjects (HS). A voxel-based analysis between these groups was used to evaluate FDG uptake in the brain and perform a correlation analysis between metabolic responses and the Sniffin' stick test as well as intensity visuo-analogue scores and disease duration (DD). A significant relative decrease of glucose metabolism in the right and left frontal lobes, left insula, right parietal lobe, and left occipital, temporal and parietal lobes was found in IAPs during OS. The same condition resulted in a relative higher glucose metabolism in the right cerebellum in IAPs. Moreover, a negative correlation between DD and FDG uptake in the left temporo-parietal joint was found in IAPs. Such a correlation suggested a possible involvement of this area metabolic decrease in self-consciousness impairment, which is known to affect IAPs. Present preliminary functional results could be of interest to further deepen such neural impairments possibly useful for future perspective in pharmaceutical and rehabilitative protocols.

Involvement of Subcortical Brain Structures During Olfactory Stimulation in Multiple Chemical Sensitivity.

Multiple chemical sensitivity (MCS) patients usually react to odour compounds and the majority of neuroimaging studies assessed, especially at the cortical level, many olfactory-related correlates. The purpose of the present study was to depict sub-cortical metabolic changes during a neutral (NC) and pure (OC) olfactory stimulation by using a recently validated (18)F-2-fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography/computer tomography procedure in 26 MCS and 11 healthy (HC) resting subjects undergoing a battery of clinical tests. Twelve subcortical volumes of interest were identified by the automated anatomical labeling library and normalized to thalamus FDG uptake. In both groups, when comparing OC to NC, the within-subjects ANOVA demonstrated a relative decreased metabolism in bilateral putamen and hippocampus and a relative increased metabolism in bilateral amygdala, olfactory cortex (OLF), caudate and pallidum. The between-groups ANOVA demonstrated in MCS a significant higher metabolism in bilateral OLF during NC. As in HC subjects negative correlations were found in OC between FDG uptake in bilateral amygdala and hippocampus and odor pleasantness scale, the latter positively correlated with MCS subjects' bilateral putamen FDG uptake in OC. Besides FDG uptake resemblances in both groups were found, for the first time a relative higher metabolism increase in OLF in MCS subjects at rest with respect to HC was found. When merging this aspect to the different subcortical FDG uptake correlations patterns in the two groups, the present study demonstrated to describe a peculiar metabolic index of behavioral and neurological aspects of MCS complaints.

Lack of contralateral suppression in transient-evoked otoacoustic emissions in multiple chemical sensitivity: a clinical correlation study.

Multiple chemical sensitivity (MCS) is a chronic disorder characterized by a variety of symptoms associated with the exposure to chemicals at a concentration below the toxic level. Previous studies have demonstrated peculiar responses in brain activity in these patients with respect to sensory stimuli while the association between chemical sensitivity and other environmental intolerances such as noise sensitivity has been questioned by researchers. In this study, a cohort of 18 MCS patients underwent transient-evoked otoacoustic emission (TEOAE) testing with and without contralateral suppression to evaluate the functionality of the medial olivocochlear (MOC) reflex involved in speech-in-noise sensitivity. Results were compared with an age- and gender-matched control group (n = 20) and correlation analysis with disease onset and quick environmental exposure sensitivity inventory (qEESI) symptom severity scale was performed. Subjects affected by MCS showed statistically significant impairment of MOC reflex, and the onset of the disease and several symptom subscales showed to be correlated to such reduction in some of the frequencies tested. These data suggest that alterations of MOC reflex could be part of the complex features of this disease although more studies are needed to further explore auditory perception disorders in environmental intolerances.

Pharmacogenetics of CYP2B6, CYP2A6 and UGT2B7 in HIV treatment in African populations: focus on efavirenz and nevirapine.

The CYP450 and UGT enzymes are involved in phase I and phase II metabolism of the majority of clinically prescribed drugs, including the non-nucleoside reverse transcriptase inhibitors, efavirenz and nevirapine, used in the treatment of HIV/AIDS. Variations in the activity of these enzymes due to gene polymorphisms can affect an individual's drug response or may lead to adverse drug reactions. There is an inter-ethnic distribution in the frequency of these polymorphisms, with African populations exhibiting higher genetic diversity compared to other populations. African specific alleles with clinical relevance have also emerged. Given the high prevalence of HIV/AIDS in sub-Saharan Africa, understanding the frequency of pharmacogenetically relevant alleles in populations of African origin, and their impact on efavirenz and nevirapine metabolism, is becoming increasingly critical. This review aims to investigate ethnic variation of CYP2B6, CYP2A6 and UGT2B7, and to understand the pharmacogenetic relevance when comparing frequencies in African populations to other populations worldwide.

Cortical activity during olfactory stimulation in multiple chemical sensitivity: a (18)F-FDG PET/CT study.

PURPOSE: To investigate the differences in brain glucose consumption during olfactory stimulation between subjects affected by multiple chemical sensitivity (MCS) and a group of healthy individuals. METHODS: Two (18)F-FDG PET/CT scans were performed in 26 subjects (6 men and 20 women; mean age 46.7 ± 11 years) with a clinical diagnosis of MCS and in 11 healthy controls (6 women and 5 men; mean age 45.7 ± 11 years), the first scan after a neutral olfactory stimulation (NS) and the second after a pure olfactory stimulation (OS). Differences in (18)F-FDG uptake were analysed by statistical parametric mapping (SPM2). RESULTS: In controls OS led to an increase in glucose consumption in BA 18 and 19 and a reduction in glucose metabolism in BA 10, 11, 32 and 47. In MCS subjects, OS led to an increase in glucose consumption in BA 20, 23, 18 and 37 and a reduction in glucose metabolism in BA 8, 9 and 10. CONCLUSION: The results of our study suggest that cortical activity in subjects with MCS differs from that in healthy individuals during olfactory stimulation.

Cytochrome P450 pharmacogenetics in African populations.

The Cytochrome P450 (CYP450) family of enzymes is involved in the oxidative metabolism of many therapeutic drugs, carcinogens and various endogenous substrates. These enzymes are highly polymorphic at an inter-individual and inter-ethnic level. Polymorphisms or genetic variations account for up to 30% of inter-individual differences seen in a variety of drug responses. The frequencies of the different metabolizer categories (slow, intermediate, extensive and ultra-rapid), the distribution of genetic variants, genotype-phenotype correlations and the clinical importance of the CYP450 enzymes have been extensively documented in Caucasian and Oriental populations. Limited data exists for African populations, despite the fact that this knowledge is critically important for these populations who experience a heavy burden of communicable and non-communicable diseases. In addition, the costs incurred through adverse drug reactions and non-responsiveness to therapy could be reduced through the wide-scale application of pharmacogenetics. This review provides an overview and investigation of CYP450 genotypic and phenotypic reports published from 1980 to present in African populations. Our findings confirm the high degree of variability that is expected when comparing individuals of African origin to other ethnic groups and also highlight the distribution of clinically relevant CYP450 alleles amongst the various African populations. The notable discordance in genotypic and phenotypic data amongst African populations exemplifies the need for in-depth and well-orchestrated molecular and pharmacological investigations of these populations in the future, for which whole genome sequencing and association studies will be critical.