Analyzing the Effect of Social Distancing Policies on Traffic at Sinchon Station, South Korea, during the COVID-19 Pandemic in 2020 and 2021.

The COVID-19 pandemic is recognized as one of the most serious global health problems, and many countries implemented lockdown measures to mitigate the effects of the crisis caused by this respiratory infectious disease. In this study, we investigated the relationship between social distancing policies and changes in traffic volume in Sinchon Station, South Korea. We used an official COVID-19 report provided by the Korea Disease Control and Prevention Agency (KCDA) and Seoul Metropolitan Government (SMG) to review social distancing policies, and the changes in traffic patterns before and during the COVID-19 pandemic between January 2020 and November 2021 were analyzed. Our study reveals that the changes in the overall traffic patterns from acceleration phases to deceleration phases of COVID-19 were related to the alert levels of social distancing policies implemented to tackle the situation resulting from the COVID-19 pandemic. Herein, we found that a significant decline in traffic volume took place from August to September 2020 (13.5−19.7%, weekday; 19.4−31.7%, weekend), from December 2020 to January 2021 (20.0%−26.6%, weekday; 26.8−34.0%, weekend), and from July to September 2021 (3.2−13.1%, weekday; 38.3−44.7%, weekend) when compared to the corresponding periods in 2019 (paired t-test; p < 0.001). The results of this study provide strong support for the effectiveness of Seoul's preemptive measures, namely, the central government's intensive social distancing campaign, in managing and reducing the impact of the pandemic situation based on the precise analysis of 10 types of facilities.

Expansion of CD45RA-FOXP3++ regulatory T cells is associated with immune tolerance in patients with combined kidney and bone marrow transplantation.

OBJECTIVES: Simultaneous transplantation of a solid organ and bone marrow from the same donor is a possible means of achieving transplant tolerance. Here, we attempted to identify biomarkers that indicate transplant tolerance for discontinuation of immunosuppressants in combined kidney and bone marrow transplantation (CKBMT). METHODS: Conventional kidney transplant (KT) recipients (n = 20) and CKBMT recipients (n = 6) were included in this study. We examined various immunological parameters by flow cytometry using peripheral blood mononuclear cells (PBMCs), including the frequency and phenotype of regulatory T (Treg) cell subpopulations. We also examined the suppressive activity of the Treg cell population in the setting of mixed lymphocyte reaction (MLR) with or without Treg cell depletion. RESULTS: Among six CKBMT recipients, three successfully discontinued immunosuppressants (tolerant group) and three could not (non-tolerant group). The CD45RA-FOXP3++ Treg cell subpopulation was expanded in CKBMT recipients compared to conventional kidney transplant patients, and this was more obvious in the tolerant group than the non-tolerant group. In addition, high suppressive activity of the Treg cell population was observed in the tolerant group. The ratio of CD45RA-FOXP3++ Treg cells to CD45RA-FOXP3+ cells indicated good discrimination between the tolerant and non-tolerant groups. CONCLUSION: Thus, our findings propose a biomarker that can distinguish CKBMT patients who achieve transplant tolerance and are eligible for discontinuation of immunosuppressants and may provide insight into tolerance mechanisms in CKBMT.

Comparative study of human and cynomolgus T-cell depletion with rabbit anti-thymocyte globulin (rATG) treatment-for dose adjustment in a non-human primate kidney transplantation model.

Rabbit-antithymocyte globulin (rATG) is commonly used in kidney transplantation (KT) as an induction agent and is also commonly used in non-human primate (NHP) KT models. However, the optimal dose has not been reported. In this study, we evaluated which cumulative dose of rATG was most appropriate for transplantation in NHPs. Cynomolgus monkeys were treated with intravenous 5 mg/kg rATG (Thymoglobulin®, Genzyme Ltd., UK) twice, on days 0 and 2 (a total of 10 mg/kg, n=2), or 4 times, on days 0, 1, 2, and 3 (a total of 20 mg/kg, n=6). In addition, we performed allo-KT in cynomolgus monkeys (n=4) with a cumulative 20 mg/kg dose of rATG with optimized dosing for induction therapy. We further compared immune cells, including naïve, central memory, and effector memory T cells, in reconstituted distributions in human KT patients (n=22). The kinetics of lymphocytes showed a rapid decrease at day 1 that was maintained for 2 weeks in the 20 mg/kg rATG group, while lymphocyte depletion was not maintained for more than 1 week in the 10 mg/kg rATG group. During the early period of rATG treatment in the NHP-KT model, the frequency of total T cells in the 20 mg/kg group showed a pattern of depletion similar with that of KT patients treated with rATG (1.5 mg/kg, 3 days). However, the pattern of reconstituted T cell subpopulations was different, as the number of effector memory cells rebounded in the NHP-KT model. These data indicate that lymphocyte-depletion induced by rATG was influenced by cumulative dose, and that an rATG dose of 20 mg/kg is suitable for induction therapy in renal transplantation in cynomolgus monkeys compared to human KT.

Simultaneously enhanced optical, electrical, and mechanical properties of highly stretchable transparent silver nanowire electrodes using organic surface modifier.

We report on a new surface modifier which simultaneously improves electrical, optical, and mechanical properties of silver nanowire-based stretchable transparent electrodes. The transparent electrodes treated with 11-aminoundecanoic acid achieve a low sheet resistance of 26.0 ohm/sq and a high transmittance of 90% with an excellent stretchability. These improvements are attributed to the effective formation of a strong chemical bond between silver nanowire networks and elastomeric substrates by 11-aminoundecanoic acid treatment. The resistance change of the optimized silver nanowire/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) thin-films is only about 10% when the film is stretched by 120%. In addition, the chemical stability of stretchable silver nanowire films is significantly improved by the introduction of conductive PEDOT:PSS overcoat film. The optimized electrodes are utilized as high-performance stretchable transparent heaters, successfully illustrating its feasibility for future wearable electronics.

Effects of desensitizing agents for cervical dentin hypersensitivity: A randomized clinical trial.

PURPOSE: To evaluate the clinical efficacy of five commercially available desensitizing agents with different mechanisms applied to hypersensitive teeth. METHODS: A randomized clinical trial was conducted on subjects suffering dentin hypersensitivity in Korea University Guro Hospital from October 2013 to April 2015. A total of 64 subjects met the selection criteria and were randomly assigned to five commercially available desensitizing agents, and applied according to the manufacturers' instructions. Before and after application of desensitizing agents, subjects were evaluated with the Visual Analogue Scale (VAS) at baseline, 1 week, 1 month and 3 months. The difference between the degree of reduction of hypersensitivity in relation to time were evaluated with the repeated-measures ANOVA (P<0.05). RESULTS: Practitioner and subject-measured VAS values at 1 week, 1 month and 3 months showed a significant difference in all products compared with the first visit. On the other hand, no statistically significant differences between the products was shown. Desensitizing agents used in this clinical trial relieved dentin hypersensitivity up to 3 months. CLINICAL SIGNIFICANCE: The five tested desensitizing agents with different mechanisms were clinically effective in relieving dentin hypersensitivity up to 3 months and showed statistically significant pain reduction when compared to baseline scores.

Bee venom acupuncture alleviates trimellitic anhydride-induced atopic dermatitis-like skin lesions in mice.

BACKGROUND: Bee venom acupuncture (BVA), a novel type of acupuncture therapy in which purified bee venom is injected into the specific acupuncture point on the diseased part of the body, is used primarily for relieving pain and other musculoskeletal symptoms. In the present study, therapeutic potential of BVA to improve atopic dermatitis, a representative allergic dysfunction, was evaluated in the mouse model of trimellitic anhydride (TMA)-induced skin impairment. METHODS: Mice were treated with 5% TMA on the dorsal flank for sensitization and subsequently treated with 2% TMA on the dorsum of both ears for an additional 12 days after a 3-day interval. From the 7(th) day of 2% TMA treatment, bilateral subcutaneous injection of BV (BV, 0.3 mg/kg) was performed daily at BL40 acupuncture points (located behind the knee) 1 h before 2% TMA treatment for 5 days. RESULTS: BVA treatment markedly inhibited the expression levels of both T helper cell type 1 (Th1) and Th2 cytokines in ear skin and lymph nodes of TMA-treated mice. Clinical features of AD-like symptoms such as ear skin symptom severity and thickness, inflammation, and lymph node weight were significantly alleviated by BV treatment. BV treatment also inhibited the proliferation and infiltration of T cells, the production of Th1 and Th2 cytokines, and the synthesis of interleukin (IL)-4 and immunoglobulin E (IgE)-typical allergic Th2 responses in blood. The inhibitory effect of BVA was more pronounced at BL40 acupoint than non-acupuncture point located at the base of the tail. CONCLUSIONS: These results indicate that BV injection at specific acupuncture points effectively alleviates AD-like skin lesions by inhibiting inflammatory and allergic responses in a TMA-induced contact hypersensitivity mouse model.

Cell motility regulation on a stepped micro pillar array device (SMPAD) with a discrete stiffness gradient.

Our tissues consist of individual cells that respond to the elasticity of their environment, which varies between and within tissues. To better understand mechanically driven cell migration, it is necessary to manipulate the stiffness gradient across a substrate. Here, we have demonstrated a new variant of the microfabricated polymeric pillar array platform that can decouple the stiffness gradient from the ECM protein area. This goal is achieved via a "stepped" micro pillar array device (SMPAD) in which the contact area with the cell was kept constant while the diameter of the pillar bodies was altered to attain the proper mechanical stiffness. Using double-step SU-8 mold fabrication, the diameter of the top of every pillar was kept uniform, whereas that of the bottom was changed, to achieve the desired substrate rigidity. Fibronectin was immobilized on the pillar tops, providing a focal adhesion site for cells. C2C12, HeLa and NIH3T3 cells were cultured on the SMPAD, and the motion of the cells was observed by time-lapse microscopy. Using this simple platform, which produces a purely physical stimulus, we observed that various types of cell behavior are affected by the mechanical stimulus of the environment. We also demonstrated directed cell migration guided by a discrete rigidity gradient by varying stiffness. Interestingly, cell velocity was highest at the highest stiffness. Our approach enables the regulation of the mechanical properties of the polymeric pillar array device and eliminates the effects of the size of the contact area. This technique is a unique tool for studying cellular motion and behavior relative to various stiffness gradients in the environment.

Spatial control of chromosomal location in a live cell with functionalized magnetic particles.

Long-range chromosomal travel is a phenomenon unique to cell division. Methods for non-invasive, artificial manipulation of chromosomes, such as optical or magnetic tweezers, have difficulty in producing the motion of whole chromosomes in live cells. Here, we report the spatial control of chromosomes over 10 µm in a live mouse oocyte using magnetic particles driven by an external magnetic field. Selective capture of the chromosomes was achieved using antibodies specific for histone H1 in the chromosome that were conjugated to magnetic particles (H1-BMPs). When an external magnetic field was applied, the chromosomes captured by the H1-BMPs traveled through the cytosol and accumulated near the cell membrane though the movement of the chromosomes captured by H1-BMPs was strongly disturbed by the distribution of the cytoskeleton (e.g. actin filaments). Being non-invasive in nature, our approach will enable new opportunities in the remote manipulation of subcellular elements.

Association of mid-pregnancy antioxidative vitamin and oxidative stress levels with infant growth during the first 3 years of life.

OBJECTIVE: Numerous studies have revealed the impacts of maternal nutritional status on subsequent birth outcome, but much less is known about the long-term impacts on infant growth after birth. We investigated the association between maternal micronutrient levels/oxidative stress status in pregnancy and infant growth during the first 3 years of life. DESIGN: Prospective cohort study. SETTING: The Ewha Birth & Growth Cohort study was constructed for women who had been recruited between 24 and 28 weeks' gestation and their offspring at Ewha Womans University Hospital. SUBJECTS: Maternal serum vitamin and urinary oxidative stress levels were measured, and infant weight, height, and head circumference were measured repeatedly at birth and at 6, 12, 18, 24, and 36 months of age. RESULTS: Maternal vitamins A and C were positively associated with infant head circumference and infant weight, respectively, during the first 3 years of life, even after controlling for potential confounding factors. But, maternal oxidative stress was not related to infant growth. CONCLUSIONS: The effects of maternal vitamin levels on subsequent infant growth during the first 3 years of life necessitate interventions to supplement antioxidative vitamins during pregnancy.

Effect of comorbidity on length of hospital stay and in-hospital mortality among unintentionally injured patients.

OBJECTIVES: Because comorbidity is a crucial issue in medical practice and research, this study evaluated the effect of comorbidity on the length of hospital stay and mortality among unintentionally injured patients. METHODS: Korea National Hospital Discharge In-depth Injury Survey 2005 data were used, and the odds ratios for in-hospital mortality and long hospital stay were estimated for injured patients with and without comorbidity. The factors evaluated were the injury mechanisms; patient age, sex and residence; and hospital size. RESULTS: In general, pre-existing diseases were associated with longer hospital stays after injury and increased the risk of death. Controlling for age, sex, residence, cause of injury and hospital size indicated that unintentionally injured patients with comorbidity experienced higher in-hospital mortality (OR=2.23) and longer hospital stays (OR=1.90). The greatest risk of death was associated with coagulopathy (OR=18.5) and fluid and electrolyte disorder (OR=13.8); the greatest risk of a long hospital stay was associated with Alzheimer's disease (OR=10.3) and paralysis (OR=5.8). The prognosis for cases involving drowning, traffic accidents and poisoning was most often affected by comorbidity (OR=15.1, 2.5, 2.5 for mortality). Comorbid patients injured in falls and fires were hospitalized 6.2 and 4.0 times longer, respectively, than those who did not have comorbid conditions. CONCLUSIONS: It is necessary to identify and manage pre-existing disease among unintentional injury patients, and collaboration with other health care providers is important to the prognosis of injured patients.

Change in causes of injury-related deaths in South Korea, 1996-2006.

BACKGROUND: The aims of this study were to describe temporal patterns of injury-related mortality by sex, age group, and mechanism, and to identify changes in the leading causes of injury-related deaths in South Korea from 1996 through 2006. METHODS: This retrospective, descriptive study analyzed national data on all injury-related deaths reported in official death certificates from 1996-2006. Incidence rates of fatal injuries are presented as crude and age-standardized rates per 100 000 population, and percentage changes in injury-related mortalities over the 11-year period were calculated with respect to intention, sex, and age. The 4 most common mechanisms (fall, poisoning, suffocation, and drowning) were then classified as unintentional injuries or suicides. RESULTS: Overall injury-related mortality decreased 31.7% during the study period (1996-2006). Despite this overall decreasing trend, injury-related mortality increased among adults aged 65 years or older. In particular, injury-related mortality among women older than 80 years doubled since 1996. Suicide replaced transport as the leading cause of injury-related deaths between 2003 and 2006. With regard to intention, sex, and age, the most noticeable changes during the study period were increases in unintentional fall among elderly adults and suicidal fall among adolescents. CONCLUSIONS: The incidence rate for all injuries generally decreased from 1996-2006. However, the incidence rate of fall injuries increased among elderly adults, and suicide increased among adolescents. These findings suggest that further investigation of the characteristics and trends of injuries is necessary to develop and implement effective interventions.

Injury prevention priority setting based on the National Injury Surveillance data in Korea.

For the reduction of injury burden, injury prevention efforts are essential. However, financial, material and human resources are far from sufficient, and this situation necessitates setting priorities for effective injury prevention. Hence, the aim of this study is to prioritise 13 injury mechanisms for prevention of injury using four injury burden criteria. National death certificate, hospital discharge data and emergency data during 2004 were used. According to the 13 most frequent injury mechanisms (ICD-10), mortality priority score, years of potential life lost (YPLL) priority score, morbidity priority score and hospital charge priority score were calculated. Injury mechanisms which were ranked fourth or higher on at least three of the four criteria scores were arranged in rank orders. Traffic crashes ranked highest on all four of the priority criteria for injury prevention followed by fall and poisoning in second and third positions, respectively. Categorised by age groups, in 0-19 year olds, traffic crashes, suffocation and drowning; in 20-59 years, traffic crashes, suffocation and poisoning; and in 60 and over, traffic crashes and fall were shown to be significant injury prevention priority in rank orders. Injury prevention priorities identified from this study could be useful in strategically allocating limited resources and implementing more focused prevention policies in Korea.

Parental socioeconomic status and unintentional injury deaths in early childhood: consideration of injury mechanisms, age at death, and gender.

The aim of this study was to determine whether the socioeconomic status (SES) of parents influences early childhood unintentional injury deaths for different injury mechanisms and the gender and age at death of the child. Study design is a population-based retrospective study. Death certificate data from 1995 to 2004 were linked to birth certificate data from 1995 to 1996 for each child who died when aged < or = 8 years. Parental age, birth order, marital status, residence area, educational level, and occupation were used as indices for SES. Cox proportional-hazards analysis was employed. Our results indicate that nonmetropolitan residence, low parental education level, and a father working in a nonadministrative job or as a farmer were associated with a higher risk of death from injury for both boys and girls. A mother aged younger than 20 years and parents working in manual jobs were associated with a higher risk in boys only. The risks of some socioeconomic factors (low parental education and a father working in a manual job or as a farmer) were evident for children aged 1-4 years. The risks of rural residency tended to increase in older children, and the risk of injury from having a mother aged younger than 20 years increased for younger children. The risks of childhood injury deaths from traffic accidents, falls, and fire/burns were associated with the SES of the parents. Younger parents were associated with higher risks of injury deaths from traffic accidents (hazard ratio [HR]: father, 7.9; mother, 1.9) and falls (HR: father, 2.0; mother, 2.5). A father working as a farmer was associated with a higher risk of childhood injury death from fire/burns (HR = 4.0). In conclusion, the parental SES risk profiles of childhood injury deaths varied with the age and gender of the child, and with the injury mechanism. Therefore, reducing excess injury deaths during early childhood requires preventive efforts targeted at high-risk parents, and based on injury mechanism and on the gender and age of the child.

Comparison of the risk-taking behaviours of children and the practices adopted by their caregivers for improving home safety.

OBJECTIVES: The objectives of this study were: (1) to describe the efforts of caregivers to provide a safe home environment for their children and the risk-taking behaviours of children; (2) to determine the efficacy of caregivers' practices for providing a safe environment on the risk-taking behaviours of children; (3) to identify factors influencing the home-safety practices adopted by caregivers for their children; and (4) to determine the information sources that caregivers use for preventing in-home injuries in their children. STUDY DESIGN: Cross-sectional study METHODS: The sample consisted of 563 pairs of elementary students and their caregivers, who were administered home-safety questionnaires at school and home, respectively. Five hundred and one matched pairs were included in the analysis. RESULTS: Caregivers' provision of a safe environment resulted in a reduced level of risk-taking behaviours in children, with this improving with sociodemographic status, higher paternal educational level, higher income level, living in an apartment, and for male children. Television and radio were the primary sources of information about preventing childhood in-home injuries, with only 38.0% of the caregivers listing doctors or hospitals as an information source. CONCLUSION: The data from this study indicate the vital roles played by caregivers in managing the risk of injury to young children and preventing injuries in the home.

Association of antioxidant vitamins and oxidative stress levels in pregnancy with infant growth during the first year of life.

OBJECTIVE: Whereas there are numerous reports in the literature relating the impact of maternal nutritional status on subsequent birth outcome, much less is known about the long-term impact on infant growth after birth. Therefore, we conducted a prospective cohort study to investigate the association of maternal micronutrient status (vitamins A, C and E, folate) and oxidative stress status in pregnancy with infant growth during the first year of life. DESIGN: Prospective cohort study. SETTING: Outpatient clinic of obstetrics, Ewha Womans University Hospital, Seoul, South Korea. SUBJECTS AND METHODS: Two groups were constructed for this study - the Ewha pregnancy cohort (n = 677) and the infant growth cohort comprising follow-up live newborns of all the recruited pregnant women (n = 317). Maternal serum vitamin and urinary oxidative stress levels were collected and infant weights and heights were measured at birth and at 6 and 12 months after birth. RESULTS: Division of the subjects into folate-deficient and normal groups revealed that infant weight and height at 0, 6 and 12 months were adversely affected by folate deficiency. High maternal vitamin C was associated with increased infant weight and height at birth and after birth. CONCLUSION: Our findings indicate the importance of preventing folate deficiency and supplementing vitamin C during pregnancy.

[Clustering of metabolic risk factors and its related risk factors in young schoolchildren].

OBJECTIVES: We wanted to determine the distribution of the clustering of the metabolic risk factors and we wanted to evaluate the related factors in young schoolchildren. METHODS: A cross-sectional study of metabolic syndrome was conducted in an elementary school in Seoul, Korea. We evaluated fasting glucose, triglyceride, HDL cholesterol, blood pressures and the body mass index, and we used parent-reported questionnaires to assess the potential risk factors in 261 children (136 boys, 125 girls). We defined the metabolic risk factors as obesity or at risk for obesity (> or = 85th percentile for age and gender), a systolic or diastolic blood pressure at > or = 90th percentile for age and gender, fasting glucose at > or = 110 mg/dl, triglyceride at > or = 110 mg/dl and HDL cholesterol at < or = 40 mg/dl. RESULTS: There were 15.7% of the subjects who showed clustering of two or more metabolic risk factors, 2.3% of the subjects who showed clustering for three or more risk factors, and 0.8% of the subjects who showed clustering for four or more risk factors. A multivariate analysis revealed that a father smoking more than 20 cigarettes per day, a mother with a body mass index of = 25 kg/m2, and the child eating precooked or frozen food more than once per day were associated with clustering of two or more components, with the odds ratios of 3.61 (95% CI = 1.24-10.48), 5.50 (95% CI=1.39-21.73) and 8.04 (95% CI = 1.67-38.81), respectively. CONCLUSIONS: This study shows that clustering of the metabolic risk factors is present in young schoolchildren in Korea, with the clustering being associated with parental smoking and obesity as well as the child's eating behavior. These results suggest that evaluation of metabolic risk factors and intervention for lifestyle factors may be needed in both young Korean children and their parents.

Risk factors for benign prostatic hyperplasia in South Korean men.

OBJECTIVES: Benign prostatic hyperplasia (BPH) is the most common prostate disease in middle-aged and elderly men, and leads to severe impairment in later life. Despite the significant effect on public health, the causes of BPH have received little attention. Identifying risk factors for BPH is crucial for understanding the etiology and for determining effective interventions or targeting strategies. METHODS: This survey was performed in two steps: (1) a pilot study was first conducted prior to the main study in order to estimate baseline characteristics, and (2) the main study investigated the prevalence and risk factors of BPH using clinical diagnostic tests and a questionnaire. A total of 641 males, aged 50-79 years, participated in this community-based cross-sectional study. RESULTS: Age was the only significant demographic risk factor of BPH. The presence of chronic bronchitis and a high prostate-specific antigen (PSA) level increased the risk by three- and twofold, respectively. The risk decreased as drinking frequency increased. Physical activity 3-5 times/week reduced the risk relative to being active less than twice per week; however, engaging in physical activity nearly everyday increased the risk 1.7-fold relative to being active up to twice per week. CONCLUSIONS: Although BPH has been considered a disease that is unavoidable with advancing age, the clear identification and control of the underlying risk factors might allow effective prevention by placing a special emphasis on those at risk.

Immersed finite element method and its applications to biological systems.

This paper summarizes the newly developed immersed finite element method (IFEM) and its applications to the modeling of biological systems. This work was inspired by the pioneering work of Professor T.J.R. Hughes in solving fluid-structure interaction problems. In IFEM, a Lagrangian solid mesh moves on top of a background Eulerian fluid mesh which spans the entire computational domain. Hence, mesh generation is greatly simplified. Moreover, both fluid and solid domains are modeled with the finite element method and the continuity between the fluid and solid subdomains is enforced via the interpolation of the velocities and the distribution of the forces with the reproducing Kernel particle method (RKPM) delta function. The proposed method is used to study the fluid-structure interaction problems encountered in human cardiovascular systems. Currently, the heart modeling is being constructed and the deployment process of an angioplasty stent has been simulated. Some preliminary results on monocyte and platelet deposition are presented. Blood rheology, in particular, the shear-rate dependent de-aggregation of red blood cell (RBC) clusters and the transport of deformable cells, are modeled. Furthermore, IFEM is combined with electrokinetics to study the mechanisms of nano/bio filament assembly for the understanding of cell motility.

The relationship between PTC taster status and taste thresholds in young adults.

OBJECTIVE: The aim of this study was to compare taste detection and recognition thresholds of young males and females, and young phenylthiocarbamide (PTC) "tasters" and "nontasters" for stimuli representing sweet, sour, bitter, salty, and umami classes of taste sensations. STUDY DESIGN: Thirty-eight men and 37 women (mean [SD] age = 24.5 [2.5] years) were classified as PTC tasters and nontasters according to their PTC recognition thresholds. Detection and recognition thresholds for the non-PTC stimuli were determined using a 2-alternative, forced choice procedure. RESULTS: The detection thresholds for quinine-HCl and sucrose and the recognition threshold for quinine-HCl were significantly higher in the PTC nontasters than in the tasters. The PTC threshold showed significant correlations with detection or recognition thresholds for sucrose, sodium chloride, quinine-HCl, and monosodium glutamate. The sucrose recognition threshold was lower in women than in men. CONCLUSION: In this study, gender and PTC taster status were found to be associated with thresholds for sucrose and quinine-HCl.