The unintended consequences of artificial intelligence in paediatric radiology

Over the past decade, there has been a dramatic rise in the interest relating to the application of artificial intelligence (AI) in radiology. Originally only 'narrow' AI tasks were possible; however, with increasing availability of data, teamed with ease of access to powerful computer processing capabilities, we are becoming more able to generate complex and nuanced prediction models and elaborate solutions for healthcare. Nevertheless, these AI models are not without their failings, and sometimes the intended use for these solutions may not lead to predictable impacts for patients, society or those working within the healthcare profession. In this article, we provide an overview of the latest opinions regarding AI ethics, bias, limitations, challenges and considerations that we should all contemplate in this exciting and expanding field, with a special attention to how this applies to the unique aspects of a paediatric population. By embracing AI technology and fostering a multidisciplinary approach, it is hoped that we can harness the power AI brings whilst minimising harm and ensuring a beneficial impact on radiology practice.

Analysis of the Trends of Methicillin-Resistant Staphylococcus aureus in Gauteng Public Hospitals from 2009 to 2018

Most investigations into the distribution of methicillin resistant Staphylococcus aureus (MRSA) have focused exclusively on bloodborne infections within individual health care institutions for shorter time periods. This has limited the analysis of a community-spread pathogen to snapshots within the hospital domain. Therefore, in this study we determined the demographic and geographical patterns of MRSA infections and their fluctuation in 10 years within all public hospitals in Gauteng, South Africa. A retrospective analysis of S. aureus samples was done by deduplicating samples in two groups. The sample groups were placed into subsets with respect to demographic and geographical fields and compared across the studied period. Logistic regression was utilized to determine odds ratios for resistant infections in univariate and multivariable configurations. A total of 66,071 unique infectious events were identified from the 148,065 samples received over a 10-year period, out of which 14,356 were identified as bacteremia. MRSA bacteremia rates in Gauteng peaked in 2015 and have since decreased. Within Gauteng, metropolitan areas have the greatest burden of MRSA with children under 5 years of age and males being most affected. Medical wards have the highest S. aureus bacteremia rates, while intensive care units have the highest MRSA bacteremia rates. Patient age, admitting ward, and geographical district are the most important associated factors of resistance. MRSA acquisition rates have shown tremendous growth since 2009 but have since spiked and subsequently decreased. This may be due to the initiation of the National Guidelines on Antimicrobial Stewardship and Infectious Disease Surveillance. Further studies to determine the trajectory of infections are required to support these claims. IMPORTANCE S. aureus is the leading cause of a variety of devastating clinical conditions, including infective endocarditis, bacteremia, and pleuropulmonary infections. It is an important pathogen responsible for substantial morbidity and mortality. MRSA is a variant of interest originally responsible for difficult to treat hospital-acquired infections that has since achieved community spread throughout the world. Most investigations into the distribution of MRSA have focused exclusively on bloodborne infections within individual health care institutions for shorter periods. This has limited the analysis of a community-spread pathogen to snapshots within the hospital domain. This study sought to determine the demographic and geographical patterns of MRSA infections as well as how these have fluctuated over time within all public hospitals. This will also help in understanding the epidemiology and resistance trends of S. aureus, which will help clinicians to understand the clinical prospective and policy makers to design guidelines and strategies for treating such infections.

Utility of a machine-guided tool for assessing risk behaviour associated with contracting HIV in three sites in South Africa

Introduction

Digital data collection and the associated mobile health technologies have allowed for the recent exploration of artificial intelligence as a tool for combatting the HIV epidemic. Machine learning has been found to be useful both in HIV risk prediction and as a decision support tool for guiding pre-exposure prophylaxis (PrEP) treatment. This paper reports data from two sequential studies evaluating the viability of using machine learning to predict the susceptibility of adults to HIV infection using responses from a digital survey deployed in a high burden, low-resource setting.

Methods

1036 and 593 participants were recruited across two trials. The first trial was a cross-sectional study in one location and the second trial was a cohort study across three trial sites. The data from the studies were merged, partitioned using standard techniques, and then used to train and evaluate multiple different machine learning models and select and evaluate a final model. Variable importance estimates were calculated using the PIMP and SHAP methodologies.

Results

Characteristics associated with HIV were consistent across both studies. Overall, HIV positive patients had a higher median age (34 [IQR: 29-39] vs 26 [IQR 22-33], p < 0.001), and were more likely to be female (155/703 [22%] vs 107/927 [12%], p < 0.001). HIV positive participants also had more commonly gone a year or more since their last HIV test (183/262 [70%] vs 540/1368 [39%], p < 0.001) and were less likely to report consistent condom usage (113/262 [43%] vs 758/1368 [55%], p < 0.001). Patients who reported TB symptoms were more likely to be HIV positive. The trained models had accuracy values (AUROCs) ranging from 78.5% to 82.8%. A boosted tree model performed best with a sensitivity of 84% (95% CI 72-92), specificity of 71% (95% CI 67-76), and a negative predictive value of 95% (95% CI 93-96) in a hold-out dataset. Age, duration since last HIV test, and number of male sexual partners were consistently three of the four most important variables across both variable importance estimates.

Conclusions

This study has highlighted the synergies present between mobile health and machine learning in HIV. It has been demonstrated that a viable ML model can be built using digital survey data from an low-middle income setting with potential utility in directing health resources.

The role of machine learning in HIV risk prediction

Despite advances in reducing HIV-related mortality, persistently high HIV incidence rates are undermining global efforts to end the epidemic by 2030. The UNAIDS Fast-track targets as well as other preventative strategies, such as pre-exposure prophylaxis, have been identified as priority areas to reduce the ongoing transmission threatening to undermine recent progress. Accurate and granular risk prediction is critical for these campaigns but is often lacking in regions where the burden is highest. Owing to their ability to capture complex interactions between data, machine learning and artificial intelligence algorithms have proven effective at predicting the risk of HIV infection in both high resource and low resource settings. However, interpretability of these algorithms presents a challenge to the understanding and adoption of these algorithms. In this perspectives article, we provide an introduction to machine learning and discuss some of the important considerations when choosing the variables used in model development and when evaluating the performance of different machine learning algorithms, as well as the role emerging tools such as Shapely Additive Explanations may play in helping understand and decompose these models in the context of HIV. Finally, we discuss some of the potential public health and clinical use cases for such decomposed risk assessment models in directing testing and preventative interventions including pre-exposure prophylaxis, as well as highlight the potential integration synergies with algorithms that predict the risk of sexually transmitted infections and tuberculosis.

Evaluating the Clinical Realism of Synthetic Chest X-Rays Generated Using Progressively Growing GANs

Chest X-rays are a vital diagnostic tool in the workup of many patients. Similar to most medical imaging modalities, they are profoundly multi-modal and are capable of visualising a variety of combinations of conditions. There is an ever pressing need for greater quantities of labelled images to drive forward the development of diagnostic tools; however, this is in direct opposition to concerns regarding patient confidentiality which constrains access through permission requests and ethics approvals. Previous work has sought to address these concerns by creating class-specific generative adversarial networks (GANs) that synthesise images to augment training data. These approaches cannot be scaled as they introduce computational trade offs between model size and class number which places fixed limits on the quality that such generates can achieve. We address this concern by introducing latent class optimisation which enables efficient, multi-modal sampling from a GAN and with which we synthesise a large archive of labelled generates. We apply a Progressive Growing GAN (PGGAN) to the task of unsupervised X-ray synthesis and have radiologists evaluate the clinical realism of the resultant samples. We provide an in depth review of the properties of varying pathologies seen on generates as well as an overview of the extent of disease diversity captured by the model. We validate the application of the Fréchet Inception Distance (FID) to measure the quality of X-ray generates and find that they are similar to other high-resolution tasks. We quantify X-ray clinical realism by asking radiologists to distinguish between real and fake scans and find that generates are more likely to be classed as real than by chance, but there is still progress required to achieve true realism. We confirm these findings by evaluating synthetic classification model performance on real scans. We conclude by discussing the limitations of PGGAN generates and how to achieve controllable, realistic generates going forward. We release our source code, model weights, and an archive of labelled generates.

Between-Habitat Variation of Benthic Cover, Reef Fish Assemblage and Feeding Pressure on the Benthos at the Only Atoll in South Atlantic: Rocas Atoll, NE Brazil

The Southwestern Atlantic harbors unique and relatively understudied reef systems, including the only atoll in South Atlantic: Rocas atoll. Located 230 km off the NE Brazilian coast, Rocas is formed by coralline red algae and vermetid mollusks, and is potentially one of the most "pristine" areas in Southwestern Atlantic. We provide the first comprehensive and integrative description of the fish and benthic communities inhabiting different shallow reef habitats of Rocas. We studied two contrasting tide pool habitats: open pools, which communicate with the open ocean even during low tides, thus more exposed to wave action; and closed pools, which remain isolated during low tide and are comparatively less exposed. Reef fish assemblages, benthic cover, algal turfs and fish feeding pressure on the benthos remarkably varied between open and closed pools. The planktivore Thalassoma noronhanum was the most abundant fish species in both habitats. In terms of biomass, the lemon shark Negaprion brevirostris and the omnivore Melichtys niger were dominant in open pools, while herbivorous fishes (mainly Acanthurus spp.) prevailed in closed pools. Overall benthic cover was dominated by algal turfs, composed of articulated calcareous algae in open pools and non-calcified algae in closed pools. Feeding pressure was dominated by acanthurids and was 10-fold lower in open pools than in closed pools. Besides different wave exposure conditions, such pattern could also be related to the presence of sharks in open pools, prompting herbivorous fish to feed more in closed pools. This might indirectly affect the structure of reef fish assemblages and benthic communities. The macroalgae Digenea simplex, which is uncommon in closed pools and abundant in the reef flat, was highly preferred in herbivory assays, indicating that herbivory by fishes might be shaping this distribution pattern. The variations in benthic and reef fish communities, and feeding pressure on the benthos between open and closed pools suggest that the dynamics in open pools is mostly driven by physical factors and the tolerance of organisms to harsh conditions, while in closed pools direct and indirect effects of species interactions also play an important role. Understanding the mechanisms shaping biological communities and how they scale-up to ecosystem functioning is particularly important on isolated near-pristine systems where natural processes can still be studied under limited human impact.

Peripheral blood gene expression profiling in Sjögren's syndrome

Sjögren’s syndrome (SS) is a common chronic autoimmune disease characterized by lymphocytic infiltration of exocrine glands. Affected cases commonly present with oral and ocular dryness, thought to be the result of inflammatory cell-mediated gland dysfunction. To identify important molecular pathways involved in SS, we used high-density microarrays to define global gene expression profiles in peripheral blood. We first analyzed 21 SS cases and 23 controls and identified a prominent pattern of overexpressed genes that are inducible by interferons (IFNs). These results were confirmed by evaluation of a second independent dataset of 17 SS cases and 22 controls. Additional inflammatory and immune-related pathways with altered expression patterns in SS cases included B and T cell receptor, IGF-1, GM-CSF, PPARα/RXRα, and PI3/AKT signaling. Exploration of these data for relationships to clinical features of disease revealed that expression levels for most IFN-inducible genes were positively correlated with titers of anti-Ro/SSA (P<0.001) and anti-La/SSB (P<0.001) autoantibodies. Diagnostic and therapeutic approaches targeting IFN signaling pathway may prove most effective in the subset of SS cases who produce anti-Ro/SSA and anti-La/SSB autoantibodies. Our results strongly support innate and adaptive immune processes in the pathogenesis of SS and provide numerous candidate disease markers for further study.

Responding to victimized Alaska Native women in treatment for substance use

High rates of physical and sexual abuse have been found among Alaska Native women entering a residential treatment program in Fairbanks, Alaska. Little information, however, has been available that describes the nature of such abuse and its relationship to treatment outcome. This article describes the extent of such abuse and reviews factors involved in its onset. The implications of the findings are discussed with an emphasis on how they can be applied to enhance treatment outcome.

Gender and reported health problems in treated alcohol dependent Alaska natives

OBJECTIVE

An ongoing study of phenotypes of alcohol dependence among Alaska Natives provides the opportunity to investigate gender differences in reported health-related problems among alcohol dependent clients in three residential programs in Anchorage, Alaska.

METHOD

Clinical assessment information was obtained on 469 (263 male) subjects from consecutive admissions to each of three treatment programs. The average (SD) age of the sample was 33.7 (8.4) years. Patterns of substance use, comorbid psychopathology, overall health status, alcohol and other drug withdrawal symptoms, and psychological and physical consequences of alcohol and other drug use were examined.

RESULTS

Male and female subjects reported similar experiences with alcohol-related health problems, including symptoms of withdrawal and the psychological and physical consequences of chronic alcohol abuse. However, women were significantly more likely to have lifetime diagnoses of major depression and cocaine dependence, whereas men were more likely to have lifetime diagnoses of antisocial personality disorder and marijuana dependence. Women reported a lower overall health status, more medication use and pain complaints, and more negative consequences of cocaine abuse and withdrawal than did men.

CONCLUSIONS

Both men and women within this sample of inpatient alcohol-dependent Alaska Natives were found to have a similar early onset and rapid progression to DSM-III-R alcohol dependence, and to report a similar prevalence of alcohol-related psychological and physical problems. Reports by women of more pain symptoms, more medication use and more negative health consequences related to their cocaine abuse, compared with men in this alcohol dependent sample, suggests additional considerations for treatment planning and intervention.

Dimeric W3SO3 cluster complexes: synthesis, characterization, and potential applications as X-ray contrast agents

Our continued research on the use of heavy metal cluster complexes as a new class of X-ray contrast agents in medical diagnostic imaging is described. A series of 2:3 cluster-ligand complexes, [(W(IV)3SO3)2L3]4- (L = linear polyaminopolycarboxylate ligands), were isolated from the reaction of aqua ion [W(IV)3SO3(H2O)9]4- (prepared in large quantities through an improved literature process) with respective ligands in refluxing DMF. The salts of [(W(IV)3SO3)2L3]4- complex anions were fully characterized using routine techniques such as elemental analysis, MS, HPLC, UV-vis, IR, and NMR. The solid structures of two complex anions, [(W(IV)3SO3)2(PDTA)3]4- and [(W(IV)3SO3)2(HO-PDTA)3]4-, were determined by X-ray crystallography. They are the first examples wherein two W(IV)3SO3 clusters are complexed and linked by three ligands that contain two terminal iminodiacetate (bis-IDA) groups. Complexation of the unstable aqua ion [W(IV)3SO3(H2O)9]4- with ligands has imparted desired biological compatibility to the tungsten metal cluster. These complexes are stable and highly soluble in H2O. The potential utility of such tungsten cluster complexes as X-ray contrast agents was evaluated in both in vitro and in vivo animal studies. In addition, the syntheses of several new linear polyaminopolycarboxylate ligands used in this study are reported.

Coexistence of reef organisms in the Abrolhos Archipelago, Brazil

The first study on coexistence of reef benthic organisms in Brazilian coral reefs was done in three localities of the Abrolhos Archipelago. Organisms were recorded in concentric circle samples (10 and 20 cm in diameter) randomly laid on transects. Type and frequency of "coexistence events" between pairs of organisms were determined. Most frequent organisms (massive and branched coralline algae, Favia gravida, and Agaricia agaricites) also had many significant positive coexistence events. These results might be related to the abundances of these organisms. The most frequent coral (Siderastrea stellata), however, exhibited only a few significant coexistence events (9% of 32 tests). Since the great majority of events were positive, and since there was high variation in the species/groups involved in significant events in different localities, benthic communities of Abrolhos Archipelago may well be structured primarily by abiotic rather than biotic factors.

Alcohol dependence among Alaska Natives entering alcoholism treatment: a gender comparison

OBJECTIVE

An ongoing study of phenotypes of alcohol dependence among Alaska Natives provides an opportunity to investigate the nature and patterns of alcohol problems among Alaska Native men and women admitted to treatment in three residential programs in Anchorage, Alaska.

METHOD

A comprehensive, standardized clinical assessment (including the SSAGA-I diagnostic interview, family history information, personality traits and cognitive functioning) of consecutive admissions to each of the three programs is being undertaken by trained interviewers. To date, 200 (103 male) subjects have been assessed. The mean (+/- SD) age of the sample is 32+/-8.5 years old. The development of alcohol problems, the psychological and physical consequences of chronic drinking, the flushing response, withdrawal symptoms and comorbid lifetime psychiatric conditions were examined.

RESULTS

The sample was characterized by an early onset of drinking and an acute exacerbation and clustering of drinking problems during late adolescence, followed by the development of severe alcohol dependence. A high lifetime prevalence of DSM-III-R major depressive disorder was found, typically complicated by chronic drinking. The rates of other substance dependencies were relatively low, except for cannabis and cocaine dependence among female subjects.

CONCLUSIONS

This sample of treatment-seeking Alaska Natives was found to have an early onset and severe form of DSM-III-R alcohol dependence, with few gender differences noted. While the prevalence of alcohol abuse and alcohol dependence among Native American populations has been reported to be quite high, the onset and patterning of symptoms among this sample of treated Alaska Natives has revealed more similarities with treated alcoholics from the majority population than important differences specific to Alaska Natives.

Can minimum separation criteria ensure electromagnetic compatibility in hospitals? An experimental study

Electromagnetic interference (EMI) from radiofrequency (RF) sources can cause medical device malfunction. It has been proposed that such EMI be minimized by only operating sources of given RF powers when sufficiently separated from medical devices of given immunities. Such minimum separation criteria are estimated assuming free-space propagation, which is only valid in the ideal case. Yet proposed medical device EMC standards will require that minimum-separation criteria be listed in equipment manuals accompanying all new medical devices. It is essential that the practical utility of such minimum-separation criteria be evaluated. Fields due to an 800-MHz-type cellphone were measured in various rooms and corridors within an urban hospital, having both new (gyprock) and old (clay-block) wings. Data obtained from a calibrated antenna attached to a spectrum analyzer were repeatedly measured and averaged. Results were compared to those predicted by free-space propagation. Free-space predictions tended to overestimate measured fields in gyprock rooms and along corridors of both gyprock and clay-block construction. However, the free-space model tended to underestimate field levels predicted in clay-block rooms and in below-ground corridors. Usage of separation criteria to ensure EMC appeared useful in gyprock rooms and hospital corridors, but less so in rooms with clay-block walls or in below-ground sections of the hospital. This suggested that the latter regions should be considered as being special zones where side-by-side operation of RF sources and medical devices would require more conservative management (e.g., restriction or special approval of particular source or medical device).

ADH and ALDH polymorphisms among Alaska Natives entering treatment for alcoholism

The alcohol dehydrogenase (ADHs) and aldehyde dehydrogenases (ALDHs) involved in alcohol metabolism are polymorphic. Different alleles encode subunits of the enzymes that are related to differences in alcohol metabolism with different ethnic groups. This study examined the allele frequencies at the ADH1, ADH2, ADH3 and ALDH2 loci in Alaska Natives entering treatment for alcoholism to determine if allele frequencies at these loci differ among five distinct Alaska Native groups: Yupik and Inupiat Eskimos, Athabascan, Tlingit and Aleut. It was found that all persons were homozygous for the ADH1*1, ADH2*1 and ALDH2*1 alleles. Variations, however, were found for the allele distribution of the ADH3 genotype. Comparison with a general population sample found no differences in allele distributions for ADHs and ALDH2*1, but differences were found when comparisons were made with four Asian Groups. The study's findings suggest that the Alaska Natives are not protected from the risk of alcoholism in the same way that Asians who possess the ALDH2*2 genotype are considered to have a negative risk factor. Nor, does there appear to be any generalized differences between Alaska Native alcoholics and members of the general population with respect to the ALDH and ADH polymorphisms studied herein.

Drinking and drinking-related problems among Alaska natives

Alcohol use has adversely affected many aspects of the Alaska Native community. To a large extent, overcoming the problem of alcohol abuse may require that Alaska Natives craft individual and community solutions to detrimental health, social, and economic conditions and instill new patterns of living that inhibit alcohol abuse. An example of this approach is the Alaska Federation of Natives' "sobriety movement," a grassroots campaign to promote sobriety that emphasizes traditional values and lifestyles. The use of "healing" or other traditional methods may help Alaska Natives both recover from the trauma of decades of cultural conflict and address alcohol problems in their communities.

Long-term effects of neuromuscular rehabilitation of chronic facial paralysis

Although chronic facial dysfunction can be improved with neuromuscular biofeedback therapy, it is uncertain whether this improvement is maintained after such therapy ends, or whether post-therapy, home exercise programs optimize this improvement. We aimed to clarify these issues. Post-therapy facial function, in 38 previously treated patients, was blindly assessed using the House grading system, 1 to 41 months after ending therapy. Results were compared with pre-therapy function. It was found that post-therapy function was better than pre-therapy function in most patients (40%), it was worse in some (26%), and was unchanged in the rest. This surprising result occurred because, although most patients who recently stopped therapy (1 to 6 mo) had improved significantly, the longer other patients were out of therapy, the more they had tended to deteriorate, particularly those who had been practicing. Results suggested that unsupervised, post-therapy, home exercise programs may be detrimental, and that new post-therapy programs may be required to maintain the benefits of regular therapy.

"Silent" malfunction of a critical-care device caused by electromagnetic interference

Although there have been many previous reports of serious medical device malfunctions caused by electromagnetic interference (EMI), it is not widely recognized that many such malfunctions were "silent," having occurred without triggering a device alarm. The authors describe one such malfunction, and its implications. An 8-year-old radiant heater, which appeared to be operating normally in a neonatal intensive care unit, was observed, by mere chance, to intermittently register an increased, or decreased, neonatal skin temperature of about 1 degree C, depending on personnel movements and on its location in the room. The possibility that EMI had been the cause of this malfunction was investigated. The malfunction stopped in an adjacent windowless room, but again occurred when a 146-MHz walkie-talkie (100 mW) was used within a 1-2-m radius. More complete (0.1-1,000 MHz, 4.5-10 V/m maximum) test-chamber assessment of EMI susceptibility showed that the heater malfunctioned at electric field strengths above 0.3-1 V/m over four roughly 50-MHz bands between about 10 and 600 MHz. A previous electromagnetic environment survey had documented fairly high fields (0.01-0.3 V/m, 30-1,000 MHz) in the original malfunction area. Combined results suggested that the malfunction had been due to EMI from nearby fixed-source FM transmission antennas, which could be seen from the room's windows. The device had probably been malfunctioning for months, even though it had been regularly checked during preventive maintenance. Other identical, but newer, units functioned normally, or malfunctioned negligibly. Although operation of the older device deviated only "slightly" from normal, the consequences of this malfunction could have been serious.(ABSTRACT TRUNCATED AT 250 WORDS)

Symmetry and synkinesis during rehabilitation of unilateral facial paralysis

We evaluated biofeedback rehabilitation in patients with severe chronic unilateral facial paralysis, who had intact facial-motor innervation (House grades 3 to 5). Recovery of facial function was characterized (1) by grading facial movement symmetry, and (2) by counting the number of muscles exhibiting synkinesis during maximal execution of selected facial movements (e.g., smiling). Facial function in 21 patients typically improved by one House grade. Facial symmetry recovered rapidly during the first 5 months of treatment, and then improved more slowly. However, during this latter period, examination of the relationship between symmetry and synkinesis (visualized by a graph plotting symmetry grades on the x-axis, against the number of synkinetic muscles on the y-axis) indicated that overall facial control was improving even when House grading suggested that it was not. Such information should aid facial retraining and may clarify understanding of underlying rehabilitation mechanisms.

Minimizing synkinesis during rehabilitation of the paralyzed face: preliminary assessment of a new small-movement therapy

Neuromuscular rehabilitation can reduce the severity of chronic facial paralysis, but complete recovery is frequently impeded by synkinesis. We evaluated whether or not such synkinesis could be minimized by preventing its possible reinforcement during rehabilitation. We compared "standard" therapy, which uses the appearance of synkinesis to guide rehabilitation, with a new "small-movement" therapy, which uses smaller movements that should minimize possible subthreshold reinforcement of synkinesis. Ten subjects who had had facial paralysis for 0.5 to 27 years were randomly assigned to either therapy group. Blinded assessments were performed before and after ten 1-hour treatments given over a 1-month interval. Facial movements in both groups were significantly more symmetric after treatment. Although synkinesis tended to be reduced in the small-movement group, this reduction was not significant. The new therapy was at least as good as the standard one, and it may be better. Further studies are required to demonstrate this.

Alcohol consumption and flushing response in natives of Chukotka, Siberia

OBJECTIVE

Drinking patterns and flushing response were investigated among indigenous natives of Chukotka, Siberia (162 women, 139 men). The quantification of drinking behavior could be used for comparison with other northern peoples and as a baseline for future intervention.

METHOD

Interviews, physical examinations and blood tests were performed in the Chukotka region of Siberia.

RESULTS

28% of the men and 4.5% of the women drank at least once per week. High doses per typical drinking occasion, which averaged 177.6 g of pure alcohol in men and 74.3 g in women, were reported; 10.3% of the men and 25.5% of the women reported that they experienced facial flushing after drinking. In most cases more than 20 g of alcohol was necessary to induce flushing, and two-thirds of the flushers were able to continue drinking after flushing began. No significant relationship between flushing and frequency and quantity of drinking and the prevalence of alcohol-related symptoms was found. There was a significant association between flushing by women and reports by them of their parent's flushing.

CONCLUSIONS

Flushing by Chukotka natives and its relationship to drinking behavior is different from Oriental ALDH2-deficient flushing.

The politicization of alcohol in the USSR and its impact on the study and treatment of alcoholism

Conducting research, particularly social science or health-related research, in the former Soviet Union was difficult because of the intrusion of communist ideology on public policy, theory, research, and practice. This report provides a description of drinking and alcohol-related problems in Siberia that was not previously available for publication. It reviews how the Soviet State's policies effected the study and treatment of alcoholism in Russia, and presents a critical review of these policies that would not have been permitted under the previous regime.

Urban-rural comparisons of drug-taking behavior among Alaskan youth

This study explores drug-taking behavior among Alaskan youth in urban, rural, and semiurban communities. It finds significant differences among these locations, which are largely attributable to variations in age of first trying marijuana and alcohol. Racial group effects specific to initiation into marijuana, and gender differences related to initiation to alcohol, are also found. The implications of these findings for education and prevention of drug-taking behavior are discussed, with special emphasis on racial and cultural factors.

Serum and salivary responses to oral tetravalent reassortant rotavirus vaccine in newborns

Serum and salivary responses of 95 infants to either a standard (4 x 10(4) plaque-forming units (PFU), 47 neonates) or a high dose (4 x 10(5) PFU, 48 neonates) of tetravalent reassortant rhesus rotavirus vaccine (administered at 2 days and at 6 weeks of age) were evaluated in a double-blind clinical trial. Serum and salivary IgA antibodies to the rotavirus group A common antigen were determined by ELISA and radioimmunoassay (RIA). Serum neutralizing antibodies to rhesus rotavirus were determined by fluorescent focus reduction assay. No significant differences in responses to the high versus standard dose were noted in serum or saliva. Response was influenced by cord blood antibodies. All infants who were cord blood-negative for rhesus rotavirus neutralizing antibodies (nine who received the standard dose and 20 who received the higher dose) had serum responses, compared with 42-70% of those who were cord blood-positive. The serum response rate recorded for babies with cord blood neutralizing titres > 1000 was 44%. Infants being bottle fed had a higher serum response rate than did babies being breast fed exclusively. If serum and salivary responses were combined, the response rate reached 80% for bottle fed infants. Thus, determination of serum responses alone underestimates vaccine 'take' in infants, and more so in highly endemic areas than in areas subject only to sporadic outbreaks. However, determination of salivary responses in newborn breastfed infants may be inaccurate, due to possible persistence of antibodies derived from colostrum or breast milk.

Ethanol elimination among different racial groups

This study examined the relationship between ethanol elimination and race, specifically exploring differences among Alaskan Natives, American Indians, and whites. Native Americans, believed to be of recent Asian origin, were expected to eliminate alcohol faster than whites. The data suggested that both Native American men and women eliminated alcohol faster than whites. A relationship was also found between age, gender, and rate of alcohol elimination. The implications of these findings were reviewed and specific needs for future research were noted.

Conductivity response of porous electrodes supported on perfluorosulfonic acid membranes to acidic gas mixtures

Gold or platinum films deposited on a Nafion membrane were used to measure surface conductance of the membrane. Acidic gases such as HCI or SO2, introduced as mixtures with an inert gas, were found to affect the conductance of the membrane surface facing this mixture while the other side of the membrane was constantly supplied with a moist inert gas. The relative conductance (G/Go) is most affected within the 0-0.5 and 3-4.5 vol % ranges both for HCI and SO2. The effect is higher for the Pt-deposited than it is for the gold-deposited membrane: for an HCI concentration of 1.5 vol %, G/Go is 5 for Pt deposited on Nafion while it is only 1.3 for gold deposited on Nafion. This is attributed to different geometries and porosity of the Pt and Au electrodes. No conductance response was observed for CO2 which yields with water a much weaker acid than those formed by HCI and SO2.

Haptoglobin levels among alcoholics in Alaska

The levels of haptoglobin, plasma proteins and amino acids were studied in a non-fasting population of alcoholics. In 25 subjects, only small differences were seen between the means when Native subjects were compared to non-Native. There did not appear to be any acute phase response differences between these two groups. This study did not substantiate other reports on the correlation of the severity of alcoholism with glycoprotein synthesis.

Adaptive modification of vestibularly perceived rotation

Results from Bloomberg et al. (1991) led to the hypothesis that saccades which accompany the dark-tested vestibulo-ocular reflex (VOR) tend to move the eyes towards a vestibularly derived percept of an intended oculomotor goal: also that this is so even when that percept has been adaptively modified by suitably prolonged visual-vestibular conflict. The present experiments investigate these implications by comparing the combined VOR + saccade performance with a presumed "motor readout" of the normal and adaptively modified vestibular percept. The methods employed were similar to those of an earlier study Bloomberg et al. (1988) in which it was found that after cessation of a brief passive whole body rotation in the dark, a previously seen earth-fixed target can be accurately located by saccadic eye movements based on a vestibular memory of the preceding head rotation; the so-called "Vestibular Memory-Contingent Saccade" (VMCS) paradigm. The results showed that the vestibular perceptual response, as measured after rotation by means of the VMCS paradigm, was on average indistinguishable from the combined VOR + saccade response measured during rotation. Furthermore, this was so in both the normal and adapted states. We conclude that these findings substantiate the above hypothesis. The results incidentally reaffirm the adaptive modifiability of vestibular perception, emphasing the need for active maintenance of its proper calibration according to behavioural context.

Adaptive plasticity in the gaze stabilizing synergy of slow and saccadic eye movements

When a normal human subject is briefly turned in total darkness while trying to "look" at a spatially fixed target, the vestibulo-ocular reflex (VOR) produces slow-phase compensatory eye movements tending to hold the eyes on target. However, slow-phase compensation per se is generally inadequate in these circumstances. Nevertheless it has recently been found, that even in the dark, this inadequacy tends to be corrected by supplementary saccades usually acting in the compensatory direction. The present study further investigates this phenomenon by measuring the respective contributions of saccadic, slow-phase and overall net compensation in 9 subjects tested before and after 30% adaptive attenuation of VOR slow-phase gain. In each test series, subjects attempted to stabilize their gaze on a previously seen target during each of 40 brief (approximately 0.5 s) whole body rotations (40 degrees/s, 20 degrees amp) conducted in complete darkness. The adaptive experience comprised 2 h of full-field visual suppression of the VOR during sinusoidal rotation of subject and surround at 1/6 Hz and 40 degrees/s velocity amplitude. Before adaptation, the cumulative slow-phase and cumulative saccadic components produced on average 78% and 14% respectively of the ideal (100%) compensation, thus yielding an overall net compensation which was 92% of the desired value. After adaptation, the corresponding values in the same population were 53%, 18% and 71% respectively. Thus after adaptation, the combined saccadic-slow-phase response brought the final gaze position to a point in space that was systematically shifted in the direction of head rotation (i.e. undercompensation). Subjects re-exposed to 30 min of normal visual-vestibular interaction displayed a variety of recovery patterns using different combinations of slow and saccadic eye movements. However, there was a consistent "synergistic" tendency for saccadic eye movements to improve slow-phase performance, regardless of the subject's adaptive state. In one subject, compensatory saccadic eye movements corrected a consistent directional asymmetry in the slow-phase response. It is suggested that a conscious vestibular percept of self-rotation might underlie the combined saccadic-slow-phase response, and that the net under performance after adaptation might reflect attenuation of this percept relative to the actual rotational stimulus.

Adolescent initiation into drug-taking behavior: comparisons over a 5-year interval

Acquisition curves for six substances were compared for adolescents in two samples separated by a 5-year interval. Individual variations in initiation ages were found for different substances, but the general pattern of exposures to drugs was essentially stable over the time interval. The findings suggest that there appears to be a range of first experience with drugs that extends from 13 to 16 years. Special emphasis was given to the implications which the findings have for education and intervention programs, and for further research.

AIDS cardiomyopathy: first rule out other myocardial risk factors

Consecutive autopsies of 59 male AIDS patients revealed that 21 had other myocardial risk factors: 17 were alcohol abusers and 6 had hypertension or coronary artery disease. AIDS patients with these myocardial risk factors were older (mean age 45 versus 35 years, P less than 0.01), and were more likely to have cardiomegaly (mean heart weight 397 grams versus 350 grams, P = 0.06) than patients with AIDS alone. When evaluating patients for AIDS cardiomyopathy, other myocardial risk factors must be considered.

[An unusual case: cutaneous leishmaniasis with subcutaneous nodule--successfully treated with oral ketoconazole]

We present an unusual case of cutaneous leishmaniasis with subcutaneous nodules. Treatment with ketoconazole over 5 weeks resulted in major improvement of the lesions.

Effects of methylphenidate on adolescents with aggressive conduct disorder and ADDH: a preliminary report

The effect of methylphenidate on aggression in adolescents diagnosed with both aggressive conduct disorder and attention deficit disorder with hyperactivity was assessed in nine male adolescents. After three open trials, a placebo controlled double-blind design was used. During methylphenidate treatment of the six double-blind subjects, there was a significant reduction of aggressivity (p's less than 0.05), as measured by the Adolescent Antisocial Behavior Checklist. Conners Teacher Rating Scale Hyperactivity and Aggression scores were in the predicted directions, but the differences were not statistically significant.

Tricuspid valve endocarditis

TVE is mainly a disease of intravenous drug abusers. Although the infecting organisms are often highly virulent, they frequently respond to medical treatment. The prognosis for patients with TVE is fairly good. About 25% of TVE patients require surgical intervention. Persistent sepsis and intractable congestive heart failure are indications for surgery. Tricuspid valvulectomy without prosthetic replacement is the surgical intervention of choice. Right-sided heart failure is the principal complication after valvulectomy without a prosthesis. A significant percentage of patients require insertion of prosthetic valves at a future date.