Burnout during the COVID-19 pandemic among nurses in Taiwan: the parental role effect on burnout.

BACKGROUND: During the COVID-19 pandemic, medical workers were concerned about the care of their children or family members and the impact of being separated from them. This increased stress could harm the relationship between nurses and patients. This study assessed how medical workers' parental role may affect burnout during such a high-stress period. METHODS: This cross-sectional observational study was carried out in 2021 during the COVID-19 pandemic. The client burnout (CB) scale of the Copenhagen Burnout Inventory, the Nordic Musculoskeletal Questionnaire, and a demographic questionnaire were used. Statistical methods such as the t-test, one-way ANOVA, and univariable/multiple linear regression were applied. RESULTS: A total of 612 nurses were included in this study. The likely risk factors of CB were identified and the parenthood effect was found to be associated with reduced CB. The parental role and leisure activity with family and friends on CB were found to have an impact. Engaging in leisure activity with family and playing the role of a parent diligently will help relieve nurses' burnout from frequent contact with patients and their families, thus lowering the risk of clinical burnout. CONCLUSION: The parental role, family/friends relationships, and a complex work environment associated with nurses' burnout during the COVID-19 pandemic. This finding allows us to re-examine the importance of family life and parent-child relationships in high-stress work environments.

Elevated neutrophil-to-lymphocyte ratio combined with decreased lymphocyte-to-monocyte ratio is associated with increased peripheral airway resistance in patients with hepatic steatosis.

Although the link between hepatic steatosis and lung function has been confirmed, the focus has largely been on central airways. The association between hepatic steatosis and increased peripheral airway resistance has not yet been explored. Hepatic steatosis and increased peripheral resistance are connected with immunity dysregulation. High neutrophil-to-lymphocyte ratio (NLR) and low lymphocyte-to-monocyte ratio (LMR) have been recognized as indicators of immunity dysregulation. In this study, the association between hepatic steatosis and increased peripheral airway resistance was evaluated, and the effect of immunity dysregulation (high NLR/low LMR) on the increased peripheral airway resistance among patients with hepatic steatosis was explored. In this retrospective study, chest or abdomen CT scans and spirometry/impulse oscillometry (IOS) from 2018 to 2019 were used to identify hepatic steatosis and increased central/peripheral airway resistance in patients. Among 1391 enrolled patients, 169 (12.1%) had hepatic steatosis. After 1:1 age and abnormal ALT matching was conducted, clinical data were compared between patients with and without hepatic steatosis. A higher proportion of patients with hepatic steatosis had increased peripheral airway resistance than those without hepatic steatosis (52.7% vs 40.2%, P = .025). Old age, high body mass index, history of diabetes, and high NLR/low LMR were significantly correlated with increased peripheral airway resistance. The presence of hepatic steatosis is associated with increased peripheral airway. High NLR/low LMR is an independent associated factor of increased peripheral airway resistance in patients with hepatic steatosis. It is advisable for patients with hepatic steatosis to regularly monitor their complete blood count/differential count and undergo pulmonary function tests including IOS.

The effect of commuting time on burnout: the mediation effect of musculoskeletal pain.

OBJECTIVES: This study explores the relationship among commuting, musculoskeletal (MS) pain, and burnout. METHODS: An observational and cross-sectional study was conducted at a medical university-affiliated hospital in Taichung, Taiwan in 2021. The two questionnaire was used and they included the Copenhagen Burnout Inventory (CBI) and the Nordic Musculoskeletal Questionnaire (NMQ). All participants were invited to complete the cross-sectional survey. A multiple linear regression was assessed correlations between commuting, MS pain, and burnout. RESULTS: After excluding those with missing data, 1,615 healthcare workers were deemed valid as research participants. In multiple linear regression, commuting time longer than 50 min was associated with personal burnout (PB) in the presence of adjusted confounders; however, long commuting time was not associated with work-related burnout (WB). Furthermore, the choice of commuting method did not affect PB or WB. Notably, both neck and shoulder pain (NBSP) and ankle pain (BAP) increase the risk of PB and WB. The mediation analysis demonstrated that NBSP is a mediating factor, increasing the level of PB and WB for commuting times longer than 50 min. CONCLUSIONS: Healthcare workers who commute for more than 50 min should be considered part of a high-risk group for burnout and musculoskeletal pain. They should also be provided with resources and programs focused on burnout prevention and MS pain relief.

The descriptive analysis of civil court decisions of dental malpractice related to infection in Taiwan.

The evaluation of dental malpractice claims database is helpful to analyze the risk and lower the chances of potential litigation. In this descriptive analysis, the Taiwan Judicial Judgment Database was used to analyze the civil court decisions of dental malpractice related to infection from January 1, 2000 to August 31, 2023. After rigor verdicts reviewed, 53 dental malpractice civil judgments related to infection were included and further analyzed. Total 15 lawsuits were required to recover the punitive damages. The overall civil conviction rate was 28.3%. Two cases occurred in the dental department at medical center and 13 cases were found in the local clinics. The top one awarded compensation is dental implant. The amount of compensation was ranged from NT$ 110,000 to NT$ 3,000,000. In conclusion, this analysis can provide the important information and reference in the amounts of compensation for dental malpractice in Taiwan.

Development of a mouse model expressing a bifunctional glutathione-synthesizing enzyme to study glutathione limitation in vivo.

Glutathione (GSH) is a highly abundant tripeptide thiol that performs diverse protective and biosynthetic functions in cells. While changes in GSH availability are associated with inborn errors of metabolism, cancer, and neurodegenerative disorders, studying the limiting role of GSH in physiology and disease has been challenging due to its tight regulation. To address this, we generated cell and mouse models that express a bifunctional glutathione-synthesizing enzyme from Streptococcus thermophilus (GshF), which possesses both glutamate-cysteine ligase and glutathione synthase activities. GshF expression allows efficient production of GSH in the cytosol and mitochondria and prevents cell death in response to GSH depletion, but not ferroptosis induction, indicating that GSH is not a limiting factor under lipid peroxidation. CRISPR screens using engineered enzymes further revealed genes required for cell proliferation under cellular and mitochondrial GSH depletion. Among these, we identified the glutamate-cysteine ligase modifier subunit, GCLM, as a requirement for cellular sensitivity to buthionine sulfoximine, a glutathione synthesis inhibitor. Finally, GshF expression in mice is embryonically lethal but sustains postnatal viability when restricted to adulthood. Overall, our work identifies a conditional mouse model to investigate the limiting role of GSH in physiology and disease.

A mouse model to study glutathione limitation in vivo.

Glutathione (GSH) is a highly abundant tripeptide thiol that performs diverse protective and biosynthetic functions in cells. While changes in GSH availability are linked to many diseases, including cancer and neurodegenerative disorders, determining the function of GSH in physiology and disease has been challenging due to its tight regulation. To address this, we generated cell and mouse models that express a bifunctional glutathione-synthesizing enzyme from Streptococcus Thermophilus (GshF). GshF expression allows efficient production of GSH in the cytosol and mitochondria and prevents cell death in response to GSH depletion, but not ferroptosis, indicating that GSH is not a limiting factor under lipid peroxidation. CRISPR screens using engineered enzymes revealed metabolic liabilities under compartmentalized GSH depletion. Finally, GshF expression in mice is embryonically lethal but sustains postnatal viability when restricted to adulthood. Overall, our work identifies a conditional mouse model to investigate the role of GSH availability in physiology and disease.

Racial differences in low value care among older adult Medicare patients in US health systems: retrospective cohort study.

OBJECTIVE: To characterize racial differences in receipt of low value care (services that provide little to no benefit yet have potential for harm) among older Medicare beneficiaries overall and within health systems in the United States. DESIGN: Retrospective cohort study SETTING: 100% Medicare fee-for-service administrative data (2016-18). PARTICIPANTS: Black and White Medicare patients aged 65 or older as of 2016 and attributed to 595 health systems in the United States. MAIN OUTCOME MEASURES: Receipt of 40 low value services among Black and White patients, with and without adjustment for patient age, sex, and previous healthcare use. Additional models included health system fixed effects to assess racial differences within health systems and separately, racial composition of the health system's population to assess the relative contributions of individual patient race and health system racial composition to low value care receipt. RESULTS: The cohort included 9 833 304 patients (6.8% Black; 57.9% female). Of 40 low value services examined, Black patients had higher adjusted receipt of nine services and lower receipt of 20 services than White patients. Specifically, Black patients were more likely to receive low value acute diagnostic tests, including imaging for uncomplicated headache (6.9% v 3.2%) and head computed tomography scans for dizziness (3.1% v 1.9%). White patients had higher rates of low value screening tests and treatments, including preoperative laboratory tests (10.3% v 6.5%), prostate specific antigen tests (31.0% v 25.7%), and antibiotics for upper respiratory infections (36.6% v 32.7%; all P<0.001). Secondary analyses showed that these differences persisted within given health systems and were not explained by Black and White patients receiving care from different systems. CONCLUSIONS: Black patients were more likely to receive low value acute diagnostic tests and White patients were more likely to receive low value screening tests and treatments. Differences were generally small and were largely due to differential care within health systems. These patterns suggest potential individual, interpersonal, and structural factors that researchers, policy makers, and health system leaders might investigate and address to improve care quality and equity.

Sources of Low-Value Care Received by Medicare Beneficiaries and Associated Spending Within US Health Systems.

This cross-sectional study examines referrals for low-value health care services and associated spending by ordering clinician among Medicare beneficiaries.

Who's Accountable? Low-Value Care Received By Medicare Beneficiaries Outside Of Their Attributed Health Systems.

Policy makers and payers increasingly hold health systems accountable for spending and quality for their attributed beneficiaries. Low-value care-medical services that offer little or no benefit and have the potential for harm in specific clinical scenarios-received outside of these systems could threaten success on both fronts. Using national Medicare data for fee-for-service beneficiaries ages sixty-five and older and attributed to 595 US health systems, we describe where and from whom they received forty low-value services during 2017-18 and identify factors associated with out-of-system receipt. Forty-three percent of low-value services received by attributed beneficiaries originated from out-of-system clinicians: 38 percent from specialists, 4 percent from primary care physicians, and 1 percent from advanced practice clinicians. Recipients of low-value care were more likely to obtain that care out of system if age 75 or older (versus ages 65-74), male (versus female), non-Hispanic White (versus other races or ethnicities), rural dwelling (versus metropolitan dwelling), more medically complex, or experiencing lower continuity of care. However, out-of-system service receipt was not associated with recipients' health systems' accountable care organization status. Health systems might improve quality and reduce spending for their attributed beneficiaries by addressing out-of-system receipt of low-value care-for example, by improving continuity.

Effect of Marriage on Burnout among Healthcare Workers during the COVID-19 Pandemic.

Since the onset of the COVID-19 pandemic, burnout symptoms have been prevalent among healthcare workers. Living with spouses can be complex and was associated with an increased burnout risk during the COVID-19 pandemic. This study investigated the relationship between living with spouses and burnout among healthcare workers during the COVID-19 pandemic. We distributed questionnaires to participants working in a hospital affiliated with a medical university in Taiwan. The questionnaires were the Copenhagen Burnout Inventory, which comprises personal burnout (PB), work-related burnout (WB), and client burnout subscales; the Nordic Musculoskeletal Questionnaire; and information on basic demographic variables, family factors, living habits, work-related factors, and physical health factors. Multiple linear regression and mediation analysis were used. We obtained 1615 (63.81%) valid questionnaires. After analysis revealed that marriage was an independent risk factor for PB; however, the effect of marriage on WB was nonsignificant after controlling for risk factors. Parenthood, less alcohol use, reported sleep duration less than six hours, less overtime, less shift work, and participation in leisure activities with family and friends were found to be mediators between marriage and a lower WB level. In addition, chronic diseases, frequent neck pain, and shoulder pain were suppression factors. In summary, marriage was associated with an increased risk of PB. Married individuals sustain a high WB level because of changes in family roles, living conditions, and work conditions. Overall, helping healthcare workers to maintain well-being in marriage or family living may be effective in decreasing burnout during the COVID-19 pandemic.

Case Report: Proteinase 3 Antineutrophil Cytoplasmic Antibody-Associated Ulcerative Colitis Presenting as Recurrent Intestinal Pseudo-Obstruction in a Teenage Patient With in situ Proteinase 3 Immunohistochemical Staining.

Ulcerative colitis (UC) is a chronic relapsing inflammatory bowel disease with the colorectum as its major target organ. Involvement of the upper gastrointestinal tract in UC is rare and presents with nonspecific endoscopic and microscopic characteristics. Recent studies have demonstrated proteinase 3 antineutrophil cytoplasmic antibody (PR3-ANCA) to be a serological marker for differentiating UC from Crohn's disease in children and for detecting disease activity and nonresponse to steroid therapy and antitumor necrotizing factor-α agents. Herein, we report a 13-year-old female patient mainly presenting with recurrent bilious vomiting who was initially diagnosed with acute gastroenteritis. Intestinal pseudo-obstruction was confirmed through observation of a patent but segmentally dilated jejunum in the barium follow-through examination and other imaging; such obstruction can be attributed to backwash ileitis, superior mesenteric artery syndrome, ileus due to hypokalemia, or PR3-associated enteritis. Laboratory data revealed leukocytosis with neutrophil predominance and serum antinuclear antibody and PR3-ANCA positivity. Overlapping syndrome with autoimmune diseases was suspected. Pathology revealed a crypt abscess with aggregates of neutrophils consistent with UC but did not indicate vasculitis. The in situ immunohistochemical staining revealed PR3 density mainly in the colon and focally in the duodenum. To our knowledge, this is the first case report with in situ pathological evidence of PR3 in inflamed intestinal tissues in a patient with UC and with rare initial presentation of intestinal pseudo-obstruction-induced recurrent bilious vomiting. Whether the clinical features of the present case constitute overlap syndrome with other autoimmune disease or a disease variation of UC warrants further investigation. Notably, the patient's serum PR3-ANCA titers remained high in coincidence with increased disease activity and nonresponse to steroid therapy, but became lower after infliximab treatment. PR3-ANCA as a potential serum biomarker to aid in making differential diagnoses of UC in children, correlating disease activity, and predicting therapeutic responses was also reviewed.

A nationwide study of the risk of all-cause, sudden death, and cardiovascular mortality among antipsychotic-treated patients with schizophrenia in Taiwan.

INTRODUCTION: Studies have reported higher risks of mortality for patients with schizophrenia, compared to the general population. This study aimed to evaluate the risk of all-cause, sudden death, and cardiovascular mortality among patients with schizophrenia in terms of types of antipsychotics. METHODS: A retrospective cohort study assessed the risk of mortality among antipsychotic-treated patients with schizophrenia. The study linked the Taiwan National Health Insurance (NHI) claims and National Register of Death databases from 2001 to 2015. Patients were hierarchically assigned to the following index antipsychotic treatment groups: atypical long acting injection (LAI), typical LAI, atypical oral, and typical oral. RESULTS: A total of 68,159 antipsychotic-treated patients with schizophrenia were analyzed. Under the hierarchical grouping, the largest percentages of patients were on atypical oral antipsychotic regimens (65.51%), followed by typical oral (14.00%), typical LAI (12.84%), and atypical LAI (7.65%). Typical oral patients had the highest incidence of all-cause mortality of 27.48 per 1000 patient-years and the atypical LAI group had the lowest incidence (13.95 per 1000 patient-years). Compared to typical oral users, there were lower risks of all-cause mortality for users of atypical LAI (aHR = 0.62, 95% CI: 0.47-0.81), typical LAI (aHR = 0.65, 95% CI: 0.55-0.78), and atypical orals (aHR = 0.55, 95% CI: 0.49-0.62). CONCLUSION: Compared to typical oral users, we found a lower risk of all-cause mortality, sudden death, and cardiovascular mortality among schizophrenia users of LAIs and oral atypicals. Further research is warranted to characterize the risk of mortality among users of more recently available LAIs in the Asia Pacific region and elsewhere.

Low-Value Care at the Actionable Level of Individual Health Systems.

Importance: Low-value health care remains prevalent in the US despite decades of work to measure and reduce such care. Efforts have been only modestly effective in part because the measurement of low-value care has largely been restricted to the national or regional level, limiting actionability. Objectives: To measure and report low-value care use across and within individual health systems and identify system characteristics associated with higher use using Medicare administrative data. Design, Setting, and Participants: This retrospective cohort study of health system-attributed Medicare beneficiaries was conducted among 556 health systems in the Agency for Healthcare Research and Quality Compendium of US Health Systems and included system-attributed beneficiaries who were older than 65 years, continuously enrolled in Medicare Parts A and B for at least 12 months in 2016 or 2017, and eligible for specific low-value services. Statistical analysis was conducted from January 26 to July 15, 2021. Main Outcomes and Measures: Use of 41 individual low-value services and a composite measure of the 28 most common services among system-attributed beneficiaries, standardized to distance from the mean value. Measures were based on the Milliman MedInsight Health Waste Calculator and published claims-based definitions. Results: Across 556 health systems serving a total of 11 637 763 beneficiaries, the mean (SD) use of each of the 41 low-value services ranged from 0% (0.01%) to 28% (4%) of eligible beneficiaries. The most common low-value services were preoperative laboratory testing (mean [SD] rate, 28% [4%] of eligible beneficiaries), prostate-specific antigen testing in men older than 70 years (mean [SD] rate, 27% [8%]), and use of antipsychotic medications in patients with dementia (mean [SD] rate, 24% [8%]). In multivariable analysis, the health system characteristics associated with higher use of low-value care were smaller proportion of primary care physicians (adjusted composite score, 0.15 [95% CI, 0.04-0.26] for systems with less than the median percentage of primary care physicians vs -0.16 [95% CI, -0.27 to -0.05] for those with more than the median percentage of primary care physicians; P < .001), no major teaching hospital (adjusted composite, 0.10 [95% CI, -0.01 to 0.20] without a teaching hospital vs -0.18 [95% CI, -0.34 to -0.02] with a teaching hospital; P = .01), larger proportion of non-White patients (adjusted composite, 0.15 [95% CI, -0.02 to 0.32] for systems with >20% of non-White beneficiaries vs -0.06 [95% CI, -0.16 to 0.03] for systems with ≤20% of non-White beneficiaries; P = .04), headquartered in the South or West (adjusted composite, 0.28 [95% CI, 0.14-0.43] for the South and 0.22 [95% CI, 0.02-0.42] for the West compared with -0.09 [95% CI, -0.26 to 0.08] for the Northeast and -0.44 [95% CI, -0.60 to -0.28] for the Midwest; P < .001), and serving areas with more health care spending (adjusted composite, 0.23 [95% CI, 0.11-0.35] for areas above the median level of spending vs -0.24 [95% CI, -0.36 to -0.12] for areas below the median level of spending; P < .001). Conclusions and Relevance: The findings of this large cohort study suggest that system-level measurement and reporting of specific low-value services is feasible, enables cross-system comparisons, and reveals a broad range of low-value care use.

Targeted truncation of the ADAM17 cytoplasmic domain in mice results in protein destabilization and a hypomorphic phenotype.

A disintegrin and metalloprotease 17 (ADAM17) is a cell-surface metalloprotease that serves as the principle sheddase for tumor necrosis factor α (TNFα), interleukin-6 receptor (IL-6R), and several ligands of the epidermal growth factor receptor (EGFR), regulating these crucial signaling pathways. ADAM17 activation requires its transmembrane domain, but not its cytoplasmic domain, and little is known about the role of this domain in vivo. To investigate, we used CRISPR-Cas9 to mutate the endogenous Adam17 locus in mice to produce a mutant ADAM17 lacking its cytoplasmic domain (Adam17Δcyto). Homozygous Adam17Δcyto animals were born at a Mendelian ratio and survived into adulthood with slightly wavy hair and curled whiskers, consistent with defects in ADAM17/EGFR signaling. At birth, Adam17Δcyto mice resembled Adam17-/- mice in that they had open eyes and enlarged semilunar heart valves, but they did not have bone growth plate defects. The deletion of the cytoplasmic domain resulted in strongly decreased ADAM17 protein levels in all tissues and cells examined, providing a likely cause for the hypomorphic phenotype. In functional assays, Adam17Δcyto mouse embryonic fibroblasts and bone-marrow-derived macrophages had strongly reduced ADAM17 activity, consistent with the reduced protein levels. Nevertheless, ADAM17Δcyto could be stimulated by PMA, a well-characterized posttranslational activator of ADAM17, corroborating that the cytoplasmic domain of endogenous ADAM17 is not required for its rapid response to PMA. Taken together, these results provide the first evidence that the cytoplasmic domain of ADAM17 plays a pivotal role in vivo in regulating ADAM17 levels and function.

Generation of Mouse Model (KI and CKO) via Easi-CRISPR.

Recent development of Easi-CRISPR (Efficient additions with ssDNA inserts-CRISPR) that utilizes long single-stranded DNA (lssDNA) of 0.2-2 kbases in length as donor templates to insert large segments of novel DNA sequences or to replace endogenous genes at precise locations in the genome has enabled CRISPR-assisted genome editing to make strides toward a more simple and rapid workflow. By leveraging the notion that short single-stranded DNA oligo (<200 bases) serves as efficient donor in mouse zygotes for facilitating HDR-mediated genome editing, Easi-CRISPR expands to use lssDNA as the donor which accelerates the timeline to as little as 2 months for creating most types of genetically engineered mouse models (F0). Our lab (CGERC) has adopted Easi-CRISPR for multiple loci to generate mouse models over the past three plus years since its introduction. Here, we use two genes as examples to illustrate a step-by-step protocol for generating two commonly used models, including a knock-in (insertion of a reporter gene plus GOI) as well as a conditional knock-out model (via exon floxing). This protocol will focus more on molecular biology aspect, particularly we demonstrate two recently developed methods for lssDNA procuration: (1) PCR-based Takara Bio kit with modifications; (2) plasmid-retrieval-based CRISPR-CLIP (CRISPR-Clipped LssDNA via Incising Plasmid). Both methods are devised to retain sequence fidelity in lssDNA generated. In addition, CRISPR-CLIP directly retrieves lssDNA from DNA plasmid without using restriction enzymes through a PCR-free system hence carries virtually no restriction on sequence complexity, further mitigating limitations discussed in the original Easi-CRISPR protocol. We have alternated the use between both methods when suitable and successfully generated lssDNA templates via CRISPR-CLIP up to 3.5 kbases patched with multiple highly repetitive sequences, which is otherwise challenging to maneuver. Along with certain other modified workflow presented herein, Easi-CRISPR can be adapted to be more straightforward while applicable to generate mouse models in broader scope. (Certain figures and text passages presented in this chapter are reproduced from Shola et al. (The CRISPR J 3(2):109-122, 2020), published by Mary Ann Libert, Inc).

Clustering Analysis of Aging Diseases and Chronic Habits With Multivariate Time Series Electrocardiogram and Medical Records.

BACKGROUND: With recent technology, multivariate time-series electrocardiogram (ECG) analysis has played an important role in diagnosing cardiovascular diseases. However, discovering the association of wide range aging disease and chronic habit with ECG analysis still has room to be explored. This article mainly analyzes the possible relationship between common aging diseases or chorionic habits of medical record and ECG, such as diabetes, obesity, and hypertension, or the habit of smoking. METHODS: In the research, we first conducted different ECG features, such as those of reduced binary pattern, waveform, and wavelet and then performed a k-means clustering analysis on the correlation between ECGs and the aforementioned diseases and habits, from which it is expected to find a firm association between them and the best characteristics that can be used for future research. RESULTS: In summary, we discovered a weak and strong evidence between ECG and medical records. For strong evidence, most patients with diabetes are always assigned into a specified group no matter the number of classes in the k-means clustering, which means we can find their association between them. For weak evidence, smokers, obesity, and hypertension have less unique ECG feature vector, enabling clustering them into specific groups, so the ECGs might be used to identify smokers, obesity, and hypertension. It is also interesting that we found obesity and hypertension, which are thought to be related to cardiovascular system. However, they are not highly correlated in our clustering analysis, which might indirectly tell us that the impact of obesity and hypertension to our body is various. In addition, the clustering effect of waveform feature is better than the other two methods.

Limitation of adipose tissue by the number of embryonic progenitor cells.

Adipogenesis in adulthood replaces fat cells that turn over and can contribute to the development of obesity. However, the proliferative potential of adipocyte progenitors in vivo is unknown (Faust et al., 1976; Faust et al., 1977; Hirsch and Han, 1969; Johnson and Hirsch, 1972). We addressed this by injecting labeled wild-type embryonic stem cells into blastocysts derived from lipodystrophic A-ZIP transgenic mice, which have a genetic block in adipogenesis. In the resulting chimeric animals, wild-type ES cells are the only source of mature adipocytes. We found that when chimeric animals were fed a high-fat-diet, animals with low levels of chimerism showed a significantly lower adipose tissue mass than animals with high levels of chimerism. The difference in adipose tissue mass was attributed to variability in the amount of subcutaneous adipose tissue as the amount of visceral fat was independent of the level of chimerism. Our findings thus suggest that proliferative potential of adipocyte precursors is limited and can restrain the development of obesity.