Diagnostic performance of artificial intelligence model for pneumonia from chest radiography.

OBJECTIVE: The chest X-ray (CXR) is the most readily available and common imaging modality for the assessment of pneumonia. However, detecting pneumonia from chest radiography is a challenging task, even for experienced radiologists. An artificial intelligence (AI) model might help to diagnose pneumonia from CXR more quickly and accurately. We aim to develop an AI model for pneumonia from CXR images and to evaluate diagnostic performance with external dataset. METHODS: To train the pneumonia model, a total of 157,016 CXR images from the National Institutes of Health (NIH) and the Korean National Tuberculosis Association (KNTA) were used (normal vs. pneumonia = 120,722 vs.36,294). An ensemble model of two neural networks with DenseNet classifies each CXR image into pneumonia or not. To test the accuracy of the models, a separate external dataset of pneumonia CXR images (n = 212) from a tertiary university hospital (Gachon University Gil Medical Center GUGMC, Incheon, South Korea) was used; the diagnosis of pneumonia was based on both the chest CT findings and clinical information, and the performance evaluated using the area under the receiver operating characteristic curve (AUC). Moreover, we tested the change of the AI probability score for pneumonia using the follow-up CXR images (7 days after the diagnosis of pneumonia, n = 100). RESULTS: When the probability scores of the models that have a threshold of 0.5 for pneumonia, two models (models 1 and 4) having different pre-processing parameters on the histogram equalization distribution showed best AUC performances of 0.973 and 0.960, respectively. As expected, the ensemble model of these two models performed better than each of the classification models with 0.983 AUC. Furthermore, the AI probability score change for pneumonia showed a significant difference between improved cases and aggravated cases (Δ = -0.06 ± 0.14 vs. 0.06 ± 0.09, for 85 improved cases and 15 aggravated cases, respectively, P = 0.001) for CXR taken as a 7-day follow-up. CONCLUSIONS: The ensemble model combined two different classification models for pneumonia that performed at 0.983 AUC for an external test dataset from a completely different data source. Furthermore, AI probability scores showed significant changes between cases of different clinical prognosis, which suggest the possibility of increased efficiency and performance of the CXR reading at the diagnosis and follow-up evaluation for pneumonia.

Adaptation to new complete dentures-is the neuromuscular system outcome-oriented or effort-oriented?

OBJECTIVE: The aim of this study was to observe the adaptation strategy of the stomatognathic system during the adaptation of complete dentures, comprising masticatory parameters and subjective measures. Our hypothesis was that with new dentures, masticatory performance would increase while the effort of the system is kept constant. MATERIAL AND METHODS: Thirty-two patients received standardized new complete dentures. Masticatory performance tests were conducted with old dentures (T1), immediately after incorporation of new dentures (T2) and after an adaptation period of 3 months (T3). Patients habitually chewed the silicone-based artificial test food Optocal. The comminuted test food was analyzed and mean particle sizes (x50) were calculated. Simultaneously, surface EMGs of the anterior temporalis and masseter muscles were recorded. Specific (SMW) and total muscle work (TMW) were determined. Patients filled in the OHIP-49 questionnaire. Test conditions were compared using repeated-measures ANOVA with SPSS 22 (SPSS Inc.) RESULTS: Masticatory performance increased (P = 0.016) between old (x50 = 4.99 ± 0.28) and adapted new dentures (x50 = 4.80 ± 0.33). TMW deteriorated (P = 0.004) at T2 (from TMW1 = 119.77 ± 56.49 to TMW2 = 92.12 46.27), and increased again (P = 0.028) at T3 (TMW3 = 107.66 ± 44.65). OHIP scores decreased significantly in all subscales (P < 0.001…P = 0.046); the total score was reduced (P < 0.001) from 56.24 ± 29.05 (T1) to 34.66 ± 24.74 (T3). CONCLUSION: In complete denture wearers, masticatory performance improves over an adaptation period. Muscle work initially decreased before reaching its original level again after adaptation. Subjective parameters overestimated the functional improvements. CLINICAL SIGNIFICANCE: The subjective evaluation does not adequately reflect functional improvements. The assessment of function requires an adaptation period.

Immediate and delayed loading of two-piece reduced-diameter implants with locator-analog attachments in edentulous mandibles: One-year results from a randomized clinical trial examining clinical outcome and patient expectation.

BACKGROUND: Prosthetic management of thin alveolar ridges in the edentulous mandibles of elderly patients, especially the time of loading, the number of implants needed, and patient expectations and perception, is a challenge in implant dentistry. PURPOSE: Survival of conventionally and immediately loaded 2-piece reduced-diameter implants in the interforaminal region of the edentulous mandible supporting locator-analog attachments was evaluated. Prosthetic complications and peri-implant hygiene were also studied, and patient expectation and subjective evaluation of the treatment were documented. MATERIAL AND METHODS: Twenty-five patients with adapted complete dentures received 4 reduced-diameter implants. All anterior implants were immediately loaded. Three months later, patients were allocated by randomization to 1 of 2 treatment groups: 2 locator-analog attachments on the anterior implants (Group A); or 4 locator-analog attachments (Group B). After another 3 months patient allocation was changed (crossover design) for the next 3 months. Questionnaires with Likert scales and numeric rating scales were used to assess patients' expectations and subjective overdenture-related variables, respectively. RESULTS: One implant was lost in the immediate-loading group. Survival was 98% and 100% for immediate and delayed loading, respectively. During 12-month observation, 8 complications required aftercare. At the beginning of treatment, patients' expectations were highly positive. Subjective assessment of overdenture-related variables 3 months after immediate loading of 2 implants revealed a statistically significant improvement for most of the variables studied; this was maintained 1 year later. In the subjective assessments, there were no statistically significant differences between Groups A and B. CONCLUSION: Immediate loading of reduced-diameter implants supporting locator-analog attachments resulted in high implant survival, few prosthetic complications, good oral hygiene, and improvement of subjective denture perception in the short-term. It might be a promising treatment option, especially for elderly patients with a narrow mandibular ridge.

Biogeography of the intestinal mucosal and lumenal microbiome in the rhesus macaque.

The gut microbiome is widely studied by fecal sampling, but the extent to which stool reflects the commensal composition at intestinal sites is poorly understood. We investigated this relationship in rhesus macaques by 16S sequencing feces and paired lumenal and mucosal samples from ten sites distal to the jejunum. Stool composition correlated highly with the colonic lumen and mucosa and moderately with the distal small intestine. The mucosal microbiota varied most based on location and was enriched in oxygen-tolerant taxa (e.g., Helicobacter and Treponema), while the lumenal microbiota showed inter-individual variation and obligate anaerobe enrichment (e.g., Firmicutes). This mucosal and lumenal community variability corresponded to functional differences, such as nutrient availability. Additionally, Helicobacter, Faecalibacterium, and Lactobacillus levels in stool were highly predictive of their abundance at most other gut sites. These results quantify the composition and biogeographic relationships between gut microbial communities in macaques and support fecal sampling for translational studies.

Transcriptional profiling defines dynamics of parasite tissue sequestration during malaria infection.

BACKGROUND: During intra-erythrocytic development, late asexually replicating Plasmodium falciparum parasites sequester from peripheral circulation. This facilitates chronic infection and is linked to severe disease and organ-specific pathology including cerebral and placental malaria. Immature gametocytes - sexual stage precursor cells - likewise disappear from circulation. Recent work has demonstrated that these sexual stage parasites are located in the hematopoietic system of the bone marrow before mature gametocytes are released into the bloodstream to facilitate mosquito transmission. However, as sequestration occurs only in vivo and not during in vitro culture, the mechanisms by which it is regulated and enacted (particularly by the gametocyte stage) remain poorly understood. RESULTS: We generated the most comprehensive P. falciparum functional gene network to date by integrating global transcriptional data from a large set of asexual and sexual in vitro samples, patient-derived in vivo samples, and a new set of in vitro samples profiling sexual commitment. We defined more than 250 functional modules (clusters) of genes that are co-expressed primarily during the intra-erythrocytic parasite cycle, including 35 during sexual commitment and gametocyte development. Comparing the in vivo and in vitro datasets allowed us, for the first time, to map the time point of asexual parasite sequestration in patients to 22 hours post-invasion, confirming previous in vitro observations on the dynamics of host cell modification and cytoadherence. Moreover, we were able to define the properties of gametocyte sequestration, demonstrating the presence of two circulating gametocyte populations: gametocyte rings between 0 and approximately 30 hours post-invasion and mature gametocytes after around 7 days post-invasion. CONCLUSIONS: This study provides a bioinformatics resource for the functional elucidation of parasite life cycle dynamics and specifically demonstrates the presence of the gametocyte ring stages in circulation, adding significantly to our understanding of the dynamics of gametocyte sequestration in vivo.

Predictors of suicidal ideation in a community sample: roles of anger, self-esteem, and depression.

The objective of this cross-sectional study was to investigate the relationships of anger, self-esteem, and depression with suicidal ideation. A survey was conducted in a wide range of community areas across Jeollabuk-do Province, Korea. A total of 2964 subjects (mean age=44.4yr) participated in this study. Hierarchical regression was used to investigate predictors of suicidal ideation in terms of their sociodemographic characteristics, depression, self-esteem, and anger. Hierarchical regression analyses revealed that anger and self-esteem were significantly associated with suicidal ideation regardless of age and after controlling for depression. Moderation analysis showed that the impact of anger on suicidal ideation was significantly greater among females than males in adolescents, but not in other age groups. Additionally, there were some differences in sociodemographic predictors of suicidal ideation among age groups. Predictors included gender and family harmony in adolescents, marital status and family harmony in middle-aged individuals, and economic status and family harmony in elderly individuals. Our results revealed that anger and self-esteem play important roles in suicidal ideation beyond the effect of depression. Development and implementation of preventive strategies, including management of anger and self-esteem, could possibly reduce suicidal ideation and subsequent suicide attempts.

Inferring developmental stage composition from gene expression in human malaria.

In the current era of malaria eradication, reducing transmission is critical. Assessment of transmissibility requires tools that can accurately identify the various developmental stages of the malaria parasite, particularly those required for transmission (sexual stages). Here, we present a method for estimating relative amounts of Plasmodium falciparum asexual and sexual stages from gene expression measurements. These are modeled using constrained linear regression to characterize stage-specific expression profiles within mixed-stage populations. The resulting profiles were analyzed functionally by gene set enrichment analysis (GSEA), confirming differentially active pathways such as increased mitochondrial activity and lipid metabolism during sexual development. We validated model predictions both from microarrays and from quantitative RT-PCR (qRT-PCR) measurements, based on the expression of a small set of key transcriptional markers. This sufficient marker set was identified by backward selection from the whole genome as available from expression arrays, targeting one sentinel marker per stage. The model as learned can be applied to any new microarray or qRT-PCR transcriptional measurement. We illustrate its use in vitro in inferring changes in stage distribution following stress and drug treatment and in vivo in identifying immature and mature sexual stage carriers within patient cohorts. We believe this approach will be a valuable resource for staging lab and field samples alike and will have wide applicability in epidemiological studies of malaria transmission.

Psychiatry in Korea.

This paper reports the current status of Korean psychiatry. In 2011, there were 3005 psychiatrists and 75,000 psychiatric beds. There were 84 psychiatric residency-training hospitals in 2011, which produced about 150 psychiatry board-certified doctors annually. As for academic activity, there is the Korean Neuropsychiatric Association, a main association for neuropsychiatry, and 21 other research societies. Psychiatric residency is a 4-year training program, with different objectives for each grade. The Korean health system accepts National Health Insurance. When severely mentally ill patients register as having a mental disorder, they pay only 10% of their total medical costs. Private clinics usually see patients with less severe conditions such as anxiety, mood and eating disorders; general and university hospitals and special mental hospitals often deal with severe conditions such as schizophrenia and bipolar disorder. One great concern is an increasing trend to depend upon pharmacotherapy and neglect the role of psychotherapy. Additionally, conflicts among medical sectors are becoming fierce as other doctors request abolition of the current law that restricts them from prescribing anti-depressants for more than 60 days. The average hospitalization period of all mental care institutions was 166 days in 2010, substantially longer compared with developed countries. To win the heart of the general public, cutting edge research to improve the quality of treatment for mental diseases, reformation of psychiatric residency training programs, public campaigns to increase awareness of mental health value, and timely reflection on policy decisions should be pursued persistently.

Cognitive effects of a single dose of atypical antipsychotics in healthy volunteers compared with placebo or haloperidol.

Cognitive dysfunction in patients with schizophrenia is a strong correlate of poor outcome than any other symptom domain. To have greater knowledge about the effects of antipsychotics on cognitive function, subjects of this study were healthy volunteers who had no confounding variables typically found in patients with schizophrenia. The cognitive function of healthy volunteers in response to single doses of haloperidol, risperidone, aripiprazole, and amisulpride in a double-blind placebo-controlled trial was investigated. Assessments for the computerized neurocognitive test, mental and physical sedation, and extrapyramidal symptoms were performed within 1 week before (baseline) and approximately 4 hours after drug administration. Compared to the placebo, single administration of amisulpride at 400 mg in healthy volunteers enhanced word fluency test performance and remained intact after controlling for sedation and extrapyramidal symptoms. Significant improvement in some measurements of the computerized neurocognitive test was also observed in each antipsychotic-treated group but may have been related to practice effect. These findings suggest that amisulpride may have cognitive-enhancing effects in healthy volunteers.

Different safety profiles of risperidone and paliperidone extended-release: a double-blind, placebo-controlled trial with healthy volunteers.

OBJECTIVE: The present study investigated subjective experiences related to secondary negative symptoms and cognitive performance in healthy volunteers in response to the repeated administration of paliperidone extended-release (ER) and risperidone in a double-blind, placebo-controlled trial. METHODS: Participants (n = 32) received a fixed dose of one of three study medications for three consecutive days: 6 mg of paliperidone ER, 3 mg of risperidone, or placebo. Subjects were evaluated at baseline and after the first and third administrations of the medications by using the Neuroleptic-Induced Deficit Syndrome Scale and the Scale for the Assessment of Negative Symptoms. Cognitive function was measured at baseline and after the third administration of the medications by using the computerized neuropsychological test. RESULTS: Risperidone was associated with more detrimental subjective experiences compared with paliperidone ER and placebo (p < .05), and these differences persisted after controlling for mental and physical sedation. Analysis of computerized neuropsychological test variables revealed significant differences in the changes in Stroop word-color test results from baseline between the paliperidone ER and risperidone groups (p < .005) and between the placebo and risperidone groups (p < .005). CONCLUSIONS: These results suggest that paliperidone ER may have a better safety profile than risperidone in terms of negative subjective experiences and cognitive function among normal volunteers.

Prevalence and clinical features of Thought-Perception-Sensitivity Symptoms: results from a community survey of Korean high school students.

Epidemiologic research indicates that psychosis and depression most frequently develop during adolescence. Hence, an efficient strategy for improving youth mental health would be to focus on detection of early-stage psychosis and depression in adolescence. In this study, 1461 high school students were surveyed using self-report scales. Students who scored equal to or above the cut-off value on any of the scales and who agreed to a further examination proceeded to a second assessment, using the Kiddie Schedule for Affective Disorders and Schizophrenia and Comprehensive Assessment of At-Risk Mental States along with self-reporting scales. The estimated prevalence of adolescents at ultra-high risk (UHR) for psychosis and of depression-spectrum disorders was 1.26 and 3.69% respectively. Compared with the normal group, experiences of bullying, suicidal ideation, and suicide attempts were significantly higher in these two groups; the subjects at UHR for psychosis were found to have significantly lower academic performance and lower ratings on SCRS; and submissive behavior was more prevalent in the depression-spectrum group. Our results reveal several clinical features of adolescents at UHR for psychosis and with depression-spectrum disorder and underscore the importance of accurate assessment of and early appropriate care for these adolescents.

Coorientation of body image among older married couples.

This study examined how older husbands and wives perceived their bodies and appearance in the framework of coorientation effect. Data were collected via a mail survey of older married couples residing in three metropolitan areas in Florida. A total of 94 married couples who were 60 years older participated in this study. Results indicated that older husbands' self-assessment of appearance was positively correlated with wives' self-assessment of appearance. Husbands' evaluation of their wives' appearance was positively associated with wives' self-assessment of their own appearance (self-other agreement), and wives' evaluation of their husbands' appearance was also positively correlated with husbands' self-assessment of their own appearance (self-other agreement). In addition, husbands' evaluation of their wives' appearance corresponded to wives' evaluation of their husbands' appearance (reciprocity). These results indicated that the agreement in two spouses' self-assessment of appearance can be explained by the two coorientation effects (self-other agreement and reciprocity) occurred in two partners of married couples.

Single-particle characterization of urban aerosol particles collected in three Korean cites using low-Z electron probe X-ray microanalysis.

A recently developed single-particle analytical technique, called low-Z electron probe X-ray microanalysis (low-Z EPMA), was applied to characterize urban aerosol particles collected in three cities of Korea (Seoul, CheongJu, and ChunCheon) on single days in the winter of 1999. In this study, it is clearly demonstrated that the low-Z EPMA technique can provide detailed and quantitative information on the chemical composition of particles in the urban atmosphere. The collected aerosol particles were analyzed and classified on the basis of their chemical species. Various types of particles were identified, such as soil-derived, carbonaceous, marine-originated, and anthropogenic particles. In the sample collected in Seoul, carbonaceous, aluminosilicates, silicon dioxide, and calcium carbonate aerosol particles were abundantly encountered. In the CheongJu and ChunCheon samples, carbonaceous, aluminosilicates, reacted sea salts, and ammonium sulfate aerosol particles were often seen. However, in the CheongJu sample, ammonium sulfate particles were the most abundant in the fine fraction. Also, calcium sulfate and nitrate particles were significantly observed. In the ChunCheon sample, organic particles were the most abundant in the fine fraction. Also, sodium nitrate particles were seen at high levels. The ChunCheon sample seemed to be strongly influenced by sea-salt aerosols originating from the Yellow Sea, which is located about 115 km away from the city.