Paid Sick Leave and Sickness Benefits for employees’ economic and job security: A Scoping Review

 

In health emergencies, such as in the COVID-19 pandemic, the need to expand or introduce the Paid sick leave(PSL) and Sickness benefits(SB) increases. They are key components of the universal health coverage(UHC) and active labor market policies(ALMPs) that enable workers to take care of their health and guarantee return-to-work after recovery. This study examines effects those policies in achieving economic stability and job security of covered workers through a scoping review. Studies were selected using the search terms ‘paid sick leave', ‘sickness benefits', ‘paid sick day', and ‘earned sick leave’ in PubMed and Web of Science. Our search conducted on 6th April 2021 yielded 1,030 articles, of which 22 articles were included in the review. All articles were analyzed by the 4 sub-groups(employees, families, employers, and government) and we investigated indicators of socio-economic impacts on their lives. Articles are largely PSL(90.9%)-focused. PSL guarantees not only workers’ job security by securing employment agreement, but also their income security by promising part of wages enough to afford healthcare and living expenses during the medical treatment and recovery. Additionally, PSL attenuates employers’ financial risk, as it reduces presenteeism while increasing the return-to-work rate. Moreover, PSL and SB reduce the total healthcare and social security expenditures of the government. To sum up, PSL and SB guarantee health and labor rights by ensuring income and job security to employees while assuring financial stability to both employers, and the government. However, as the previous studies paid less attention on the equity of these impacts at the system levels, future research should more focus on the dimension.

Key messages

• PSL and SB guarantee health and labour rights by ensuring income and job security for employees, while assuring financial stability for both employers and the government.

• The previous studies that examined the effects of PSL and SB paid less attention on the equity of ensuring income and employment security, therefore future studies should focus more on this dimension.

A Sick Benefit Scheme Reduces Unmet Healthcare Needs: An Natural Experiment in Seoul

 

South Korea experiences four times more unmet healthcare needs than OECD countries (11.6% and 2.6% respectively). Unmet healthcare needs are caused by the double burden of direct and indirect costs including income loss, and OECD countries operate a sickness benefit scheme to resolve sudden loss of pay. Seoul introduced the first sickness benefit system, Seoul-Type Paid Sick Leave Support (hereinafter Seoul Sick Leave), for self-employed national healthcare insurance subscribers to reduce the rate of unmet healthcare needs. By comparing the amount of increasing medical expenses between the beneficiary and non-beneficiary before (2018) and after (2019-2020) the introduction of the system, the study was intended to confirm the reduced unmet healthcare needs. This study used data from the National Health Information Database (NHID) and the difference in differences (DID) analytic framework. 96 and 121 patients were included in benefit and non-benefit cohorts, respectively. As a result, the beneficiary group’s expenses were smaller than those of the non-beneficiary group (coef.=-1.24, p = 0.026). However, the beneficiary group had a greater amount of increase in hospitalization expenses before and after the introduction than the non-beneficiary group did (coef.=1.66, p = 0.005). Our finding showed that the Seoul Sick Leave helped the precarious workers as they were able to use inpatient services when they needed. If it is to be scaled up to the national level, it should be applied all people to enhance universal health insurance in Korea.

Key messages

• Identified the effectiveness of the first sickness benefit system as it helped the precarious workers as they were able to use inpatient services when they needed.

• By financially supporting them, the Seoul Sick Leave support can achieve health promotion through early detection and treatment.

Robotic prostatectomy after abandoned open radical prostatectomy—Technical aspects and outcomes

Objective

To describe the technical aspects and outcomes of robotic‐assisted radical prostatectomy (RARP) following abandoned open radical prostatectomy (ORP).

Patients and Methods

A retrospective review was performed of patients who underwent RARP following abandonment of ORP between 2016 and 2020. RARP was undertaken by two highly experienced robotic surgeons. Analysis of patient and operative characteristics, outcomes, and reasons for abandonment of ORP were described.

Results

Six patients were included for analysis with a median age of 63.5 years [50.3‐67.5]. The median body mass index (BMI) was 34.7 [27.8‐36.2]. All patients had intermediate‐risk prostate cancer. Small prostate and deep pelvis were given as reasons for abandoning ORP in five cases (83.3%), with four of these also attributing increased BMI as a factor. Extensive mesh from previous bilateral inguinal hernia repair was cited as the reason for abandonment in the remaining patient. One patient had commenced androgen deprivation therapy following abandoned ORP. Extensive retropubic adhesions were noted at the time of RARP in five of six patients, with intraoperative complication of small bladder lacerations encountered in the patient with prior mesh hernia repair. The median time from abandoned ORP to RARP was 128 days [40‐216]. Median operating time was 160 minutes [139‐190] and estimated blood loss was 225 mL [138‐375]. Negative margins were obtained in four of six cases, with further salvage treatment being required in one case at a median follow‐up duration of 10.5 months [6.5‐25.3].

Conclusion

Abandonment of ORP is an uncommonly reported event, however, in this small case series, we demonstrate that, in the hands of experienced surgeons, RARP is a safe and technically feasible alternative in such cases. Increased BMI, small prostate size and pelvic anatomical constraints appear to be common catalysts for abandonment of open surgery in this cohort. Identifying these high‐risk patients early and considering referral to robotic centers may be preferred.

Comparison of Cancer Cell Elasticity by Cell Type

Lower cellular elasticity is a distinguishing feature of cancer cells compared with normal cells. To determine whether cellular elasticity differs based on cancer cell type, cells were selected from three different cancer types including breast, cervix, and lung. For each cancer type, one counterpart normal cell and three types of cancer cells were selected, and their elasticity was measured using atomic force microscopy (AFM). The elasticity of normal cells was in the order of MCF10A > WI-38 ≥ Ect1/E6E7 which corresponds to the counterpart normal breast, lung, and cervical cancer cells, respectively. All cancer cells exhibited lower elasticity than their counterpart normal cells. Compared with the counterpart normal cells, the difference in cellular elasticity was the greatest in cervical cancer cells, followed by lung and breast cancer cells. This result indicates lower elasticity is a unique property of cancer cells; however, the reduction in elasticity may depend on the histological origin of the cells. The F-actin cytoskeleton of cancer cells was different in structure and content from normal cells. The F-actin is mainly distributed at the periphery of cancer cells and its content was mostly lower than that seen in normal cells.

Electric field-induced changes in biomechanical properties in human dermal fibroblasts and a human skin equivalent

PURPOSE

An electric field (EF) can be used to change the mechanical properties of cells and skin tissues. We demonstrate EF-induced elasticity changes in human dermal fibroblasts (HDFs) and a human skin equivalent and identify the underlying principles related to the changes.

METHODS

HDFs and human skin equivalent were stimulated with electric fields of 1.0 V/cm. Change in cellular elasticity was determined by using atomic force microscopy. Effects of EF on the biomechanical and chemical properties of a human skin equivalent were analyzed. In cells and tissues, the effects of EF on biomarkers of cellular elasticity were investigated at the gene and protein levels.

RESULTS

In HDFs, the cellular elasticity was increased and the expression of biomarkers of cellular elasticity was regulated by the EF. Expression of the collagen protein in the human skin equivalent was changed by EF stimulation; however, changes in density and microstructure of the collagen fibrils were not significant. The viscoelasticity of the human skin equivalent increased in response to EF stimulation, but molecular changes were not observed in collagen.

CONCLUSIONS

Elasticity of cells and human skin equivalent can be regulated by electrical stimulation. Especially, the change in cellular elasticity was dependent on cell age.

Biomarkers to quantify cell migration characteristics

Background

Because cell movement is primarily driven by the connection between F-actin and integrin through a physical linkage, cellular elasticity and adhesion strength have been considered as biomarkers of cell motility. However, a consistent set of biomarkers that indicate the potential for cell motility is still lacking.

Methods

In this work, we characterize a phenotype of cell migration in terms of cellular elasticity and adhesion strength, which reveals the interdependence of subcellular systems that mediate optimal cell migration.

Results

Stiff cells weakly adhered to the substrate revealed superior motility, while soft cell migration with strong adhesion was relatively inhibited. The spatial distribution and amount of F-actin and integrin were highly variable depending on cell type, but their density exhibited linear correlations with cellular elasticity and adhesion strength, respectively.

Conclusions

The densities of F-actin and integrin exhibited linear correlations with cellular elasticity and adhesion strength, respectively, therefore, they can be considered as biomarkers to quantify cell migration characteristics.

Effects of red ginseng on the elastic properties of human skin

Background

Red ginseng contains components, including microelements, vitamins, essential oils, and fatty acids, that can be used in skincare to delay the aging process. We investigated the effects of red ginseng treatment on skin elasticity by assessing cellular stiffness and measuring collagen protein synthesis.

Methods

Human dermal fibroblasts were treated with red ginseng, and the resulting changes in stiffness were investigated using atomic force microscopy. Cytoskeletal changes and mRNA expression of biomarkers of aging, including that of procollagens I and VII, elastin, and fibrillin-1, were investigated. Collagen in a human skin equivalent treated with red ginseng was visualized via hematoxylin and eosin staining, scanning electron microscopy, and atomic force microscopy.

Results and conclusion

The stiffness of fibroblasts was significantly reduced by treatment with red ginseng concentrations of ≥ 0.8 mg/mL. The ratio of F-actin to G-actin decreased after treatment, which corresponded to a change in fibroblast stiffness. The storage modulus (G′) and loss modulus (G″) of the skin equivalent were both lowered by red ginseng treatment. This result indicates that the viscoelasticity of the skin equivalent can be restored by red ginseng treatment.

Top-up operation at Pohang Light Source-II

After three years of upgrading work, PLS-II (S. Shin, Commissioning of the PLS-II, JINST, January 2013) is now successfully operating. The top-up operation of the 3 GeV linear accelerator had to be delayed because of some challenges encountered, and PLS-II was run in decay mode at the beginning in March 2012. The main difficulties encountered in the top-up operation of PLS-II are different levels between the linear accelerator and the storage ring, the 14 narrow gap in-vacuum undulators in operation, and the full energy injection by 3 GeV linear accelerator. Large vertical emittance and energy jitter of the linac were the major obstacles that called for careful control of injected beam to reduce beam loss in the storage ring during injection. The following measures were taken to resolve these problems: (1) The high resolution Libera BPM (see http://www.i-tech.si) was implemented to measure the beam trajectory and energy. (2) Three slit systems were installed to filter the beam edge. (3) De-Qing circuit was applied to the modulator system to improve the energy stability of injected beam. As a result, the radiation by beam loss during injection is reduced drastically, and the top-up mode has been successfully operating since 19th March 2013. In this paper, we describe the experimental results of the PLS-II top-up operation and the improvement plan.

Application of a computerized language lateralization index from FMRI by a group of clinical neuroradiologists

BACKGROUND AND PURPOSE

Deriving accurate language lateralization from fMRI studies in the clinical context can be difficult, with 10%-20% incorrect conclusions. Most interpretations are qualitative, performed by neuroimaging experts. Quantitative lateralization has been widely described but with little implementation in the clinical setting and is disadvantaged by the use of arbitrary threshold techniques. We investigated the application and utility of a nonthreshold CLI, in a clinical setting, as applied by a group of practicing neuroradiologists.

MATERIALS AND METHODS

Twenty-two patients with known language lateralization (11 left and 11 nonleft dominant) had their images reviewed by 8 neuroradiologists in 2 settings, all randomized, once by using a CLI and once without using a CLI. For each review, neuroradiologists recorded their impressions of lateralization for each language sequence, the overall lateralization conclusion, their impression of scan quality and noise, and the subjective confidence in their conclusion.

RESULTS

The inter-rater κ for lateralization was 0.64, which increased to 0.70 with the use of CLI. The group accuracy of overall lateralization was 78%, which increased to 81% with the use of a CLI. Using a CLI removed 2 instances of significant errors, with a neuroradiologist's impression of left lateralization in a patient with known right lateralization. Using a CLI had no effect on examinations with conclusions formed with either high confidence or no confidence.

CONCLUSIONS

Although the overall clinical benefit of a CLI is modest, the most significant impact is to reduce the most harmful misclassification errors, particularly in fMRI examinations that are suboptimal.

Effect of a prescan patient-radiologist encounter on functional MR image quality

BACKGROUND AND PURPOSE

A substantial number of clinical fMRI examinations inadequately assess language localization or lateralization, usually due to patient movement and suboptimal participation. We hypothesized that a prescan interview of the patient by the radiologist would reduce the fraction of nondiagnostic scans.

MATERIALS AND METHODS

A single noise score for each acquisition was produced from time-series data on the basis of a weighted sum of 22 factors. Scores were recorded as the following quartiles: 0-5 = excellent, 5-10 = adequate, 10-15= marginal, and >15 = unacceptable. This measure was evaluated for 202 consecutive fMRI patients: 96 without and 106 with a physician prescan interview. The data were analyzed to compute the fraction of all nondiagnostic sequences and entire studies and were compared between the 2 groups. Image-noise characteristics included the SDs of linear and angular displacements of the head and the number of time-series outliers caused by focal motion.

RESULTS

Of 999 sequences acquired, 539 had a prescan interview. The mean noise score significantly decreased for both individual sequence (from 7.9 to 6.3, P = <.001) and study-based (from 7.7 to 6.2, P = .05) methods. The fraction of sequences or studies scored as unacceptable decreased for sequence-based (from 15.2% to 10.9%, P = .04) and study-based (from 9.4% to 1.9%, P = .02) analyses. SDs of head motion decreased for linear (by 12%-14%, P < .01) and angular displacement (by 38%-48%, P < .001). The number of time-series spikes decreased by 10% (P = .004).

CONCLUSIONS

We report that a prescan physician-patient interview modestly but significantly reduces fMRI noise scores. These results support the newly added billable costs of professional intervention before fMRI scans.

Nup211, the fission yeast homolog of Mlp1/Tpr, is involved in mRNA export

Synthetic lethal mutants have been previously isolated in fission yeast Schizosaccharomyces pombe, which genetically interact with spmex67, in order to identify the genes involved in mRNA export. The nup211 gene was isolated by complementation of the growth defect in one of the synthetic lethal mutants, SLMex2, under synthetic lethal condition. We showed that Nup211, fission yeast homolog of Mlpl/Mlp2/Tpr, is essential for vegetative growth and Nup211-GFP proteins expressed at endogenous level are localized mainly in nuclear periphery. The accumulation of poly(A)(+) RNA in the nucleus is exhibited when expression of nup211 is repressed or over-expressed. These results suggest that the Nup211 protein plays a pivotal role of mRNA export in fission yeast.

The use of complementary and alternative medicine in patients with terminal cancer in Korea: Nationwide cross-sectional study

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Background: Although the use of complementary and alternative medicine(CAM) is widespread among patients with chronic diseases including cancer, little is known about CAM use in terminal cancer patients. Methods: This study included 4,042 families of cancer patients who died at 17 hospitals in Korea between January and December 2004. We conducted with telephone survey to decedents’ families. The response rate was 41.1%. The questionnaire included whether cancer patients had used CAM during last one year before death, type of modality, motivation for use, attitudes to CAM, and consultation with doctors. Results: CAM use of cancer patients was reported by 36.3% (604 of 1,662) and the average rate of CAM cost was 32% of total medical costs during one year before patient’s death. CAM use was more likely to death at hospitals (adjusted Odds Ratio: 1.35, 95% Confidential Interval: 1.15–1.58), residence in rural (aOR:1.26, 95%CI:1.08–1.47), need consultations about care (aOR:1.65, 95%CI:1.30–2.09) and religious support (aOR:1.3, 95% CI:1.11–1.53), diagnosis except liver/gallbladder cancer (aOR:0.67, 95%CI:0.55–0.81), and longer disease period (aOR:1.85, 95% CI:1.5–2.2). Use was greatest for mushrooms (41.6%), vegetable juice (25.6%), ginseng (21.8%) and Chinese medicine (16.4%). The motivation for CAM use was the recommendations from family members or friends (83.5%) and internet or advertisement (16.1%) but physicians’ recommendation or education (1.4%) was rare. The 37.4% of families of CAM-used patients were satisfied with CAM because of but feeling better or comfortable (79.3%), not cure (5.4%). And otherwise, the 62.1% of them were unsatisfied with CAM because of no effect (87.3%). Only 41.7% CAM users consulted with their physician. Conclusions: This study revealed a high prevalence of CAM use among terminal cancer patients without recommendation from doctors. Medical staffs should evaluate patients’ CAM use and inform accurately about CAM to terminal cancer patients and family for quality of care improvement.

No significant financial relationships to disclose.

[18F]fluorothymidine (FLT) PET after 3 days of gefitinib treatment and tumor response in non-small cell lung cancer (NSCLC)

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Background: FLT has been developed as a PET tracer for imaging tumor proliferation. We evaluated whether FLT-PET could predict tumor response only after 3 days of gefitinib treatment. Methods: Nonsmokers with adenocarcinoma of the lung were eligible for this study. FLT-PET was performed at 1 day before and 3 days after the start of gefitinib (250 mg/d) therapy. The maximum standardized uptake value (SUVmax) of the main lung mass was measured, and changes in tumor SUVmax were calculated. After 6 weeks of therapy, response was assessed by chest CT according to WHO criteria. The cutoff value predicting subsequent CT response was obtained by receiver operating characteristic curve analysis. Results: Between Jun. 2005 and Nov. 2005, 22 patients were enrolled. CT response was partial response in 12 (54%), stable disease in 5 (23%), and progressive disease in 5 (23%). As early as 3 days after the initiation of therapy, significant difference in % changes of tumor SUVmax on FLT-PET was observed between responders and nonresponders (−32% v −2.3%, P = .002) ( Table ). When a reduction of tumor SUVmax ≥ 20% was used as a cutoff value for FLT-PET response, CT response could be predicted with positive and negative predictive values of 100% and 83%, respectively. Time to progression was significantly longer in FLT-PET responders than nonresponders (median 5.1 v 1.4 months, P = .011). Conclusions: Using FLT-PET obtained on days 0 and 3 of gefitinib therapy, the response could be early predicted in patients with NSCLC.

[Table: see text]

No significant financial relationships to disclose.

The impact of prostate size in laparoscopic radical prostatectomy

OBJECTIVES

Large prostates can be challenging to remove during open or laparoscopic radical prostatectomy (LRP). Our objective was to critically analyse the impact of prostate volume in LRP.

METHODS

400 cases of LRP were performed. Three hundred and fourteen patients had a small prostate (weight < 75 g) and 86 patients had a large prostate (weight > or = 75 g) on final histology. The following outcomes were assessed: operative time; estimated blood loss (EBL); transfusion rate; length of hospital stay (LOS); length of catheterisation; perioperative and postoperative complications (including incontinence and erectile dysfunction); surgical margin status; and early biochemical recurrence rates.

RESULTS

Patients' age, PSA, Gleason sum and clinical stage were all similar. Larger prostates were associated with a 14 minutes longer mean operating time (p < 0.001), but fewer positive surgical margins (p = 0.01). Blood loss, blood transfusion rate, length of hospital stay, length of catheterisation and complication rate were all similar in both groups.

CONCLUSIONS

Prostate size should not be a factor determining a patient's suitability for LRP. Further follow-up is needed to assess the effect of prostate size on long-term functional and oncological results.

The Impact of Prostate Size in Laparoscopic Radical Prostatectomy

OBJECTIVES

Large prostates can be challenging to remove during open or laparoscopic radical prostatectomy (LRP). Our objective was to critically analyse the impact of prostate volume in LRP.

METHODS

400 cases of LRP were performed. Three hundred and fourteen patients had a small prostate (weight < 75 g) and 86 patients had a large prostate (weight > or = 75 g) on final histology. The following outcomes were assessed: operative time; estimated blood loss (EBL); transfusion rate; length of hospital stay (LOS); length of catheterisation; perioperative and postoperative complications (including incontinence and erectile dysfunction); surgical margin status; and early biochemical recurrence rates.

RESULTS

Patients' age, PSA, Gleason sum and clinical stage were all similar. Larger prostates were associated with a 14 minutes longer mean operating time (p < 0.001), but fewer positive surgical margins (p = 0.01). Blood loss, blood transfusion rate, length of hospital stay, length of catheterisation and complication rate were all similar in both groups.

CONCLUSIONS

Prostate size should not be a factor determining a patient's suitability for LRP. Further follow-up is needed to assess the effect of prostate size on long-term functional and oncological results.

Determinants of outcome in melanoma patients with cerebral metastases

PURPOSE

To analyze prognostic factors, effects of treatment, and survival for patients with cerebral metastases from melanoma.

PATIENTS AND METHODS

All melanoma patients with cerebral metastases treated at the Sydney Melanoma Unit between 1952 and 2000 were identified. From 1985 to 2000, patients were diagnosed and treated using consistent modern techniques and this cohort was analyzed in detail. Multivariate analysis of prognostic factors for survival was performed.

RESULTS

A total of 1137 patients with cerebral metastases were identified; 686 were treated between 1985 and 2000. For these 686 patients, the median time from primary diagnosis to cerebral metastasis was 3.1 years (range, 0 to 41 years). A total of 646 patients (94%) have died as a result of melanoma. The median survival from the time of diagnosis of cerebral metastasis was 4.1 months (range, 0 to 17.2 years). Treatment was as follows: surgery and postoperative radiotherapy, 158 patients; surgery alone, 47 patients; radiotherapy alone, 236 patients; and supportive care alone, 210 patients. Median survival according to treatment received for these four groups was 8.9, 8.7, 3.4, and 2.1 months, respectively; the differences between surgery and nonsurgery groups were statistically significant. On multivariate analysis, significant factors associated with improved survival were surgical treatment (P <.0001), no concurrent extracerebral metastases (P <.0001), younger age (P =.0007), and longer disease-free interval (P =.036). Prognostic factors analysis confirmed the important influence of patient selection on treatment received.

CONCLUSION

This large series documents the characteristics of patients who developed cerebral metastases from melanoma. Median survival was dependent on treatment, which in turn was dependent on patient selection.

Presence of the eggshell sign in obstructive uropathy

OBJECTIVES

To analyze the relationship between hydronephrosis due to urinary tract obstruction and the presence of the sonographic eggshell sign, which is a recently described crescent of increased echogenicity at the caliceal/parenchymal interface and possibly an indicator of raised intrarenal pressure.

METHODS

All patients presenting between 1996 and 1999 for surgical management of pelviureteral junction obstruction or congenital posterior urethral obstruction had films reviewed for the presence of the eggshell sign.

RESULTS

Of 94 patients, 40 presented postnatally and 54 had hydronephrosis detected on the antenatal ultrasound scan. Of the postnatal group, 16 (40%) had urethral obstruction, of whom 4 (25%) displayed the eggshell sign; in the 24 with pelviureteral junction obstruction, the echogenic pericaliceal crescent was seen in 5 (20.8%). Of the 54 in the prenatal group, 8 (15.4%) were found to have urethral obstruction, 5 (62.5%) of whom demonstrated the eggshell sign. Of the 46 prenatally diagnosed patients with pelviureteral junction obstruction, 31 (70.5%) displayed the eggshell sign before birth; we were unable to satisfactorily review 2 patients' ultrasound scans.

CONCLUSIONS

Antenatally diagnosed hydronephrosis due to significant urinary tract obstruction seems to be related to the appearance of the eggshell sign on ultrasonography, particularly in those patients with pelviureteral junction obstruction. Those patients without significant caliceal distension and those with renal dysplasia or severe hydronephrosis with low-pressure kidneys were less likely to display the eggshell sign. Although the association with other causes of hydronephrosis is unknown, we believe these figures support the need for further investigation of the eggshell sign as a marker of raised intrarenal pressure to possibly provide another data point in the sonographic evaluation of congenital hydronephrosis.

Intrarenal cystic mass with pelviureteral junction obstruction

An abdominal mass in the first year after birth most commonly originates from the kidney. Renal masses in this age group are often cystic and may be associated with other abnormalities. We describe an unusual benign unilateral cystic lesion and coexisting pelviureteral junction obstruction in a newborn male with an otherwise morphologically and functionally normal urinary tract. A near normal kidney resulted from subsequent resection of the cyst wall combined with pyeloplasty.

Barbarin as a new tyrosinase inhibitor from Barbarea orthocerus

A tyrosinase inhibitor was isolated from the whole plant of Barbarea orthocerus Led. (Brassicaceae) by activity-guided fractionation, and identified as (R)-5-phenyl-2-oxazolidinethione (barbarin) by structural analysis followed by comparison with reported spectral data. The compound exhibited significant inhibitory effects on mushroom and murine tyrosinases at more than 1.6 x 10(-5) M. Barbarin exhibited IC50 values of 4.2 x 10(-5) M on mushroom tyrosinase and of 4.8 x 10(-5) M on murine tyrosinase. Kojic acid as a positive control exhibited IC50 values of 3.4 x 10(-5) M and 6.0 x 10(-5) M on mushroom and murine tyrosinases, respectively. Therefore, barbarin exhibited a similar level of inhibitory potency with kojic acid used as a positive control. In a kinetic study with various concentrations of L-dopa as the substrate, barbarin was identified as an uncompetitive inhibitor and kojic acid as a mixed inhibitor of both mushroom and murine tyrosinases. Barbarin exhibited KEIS values of 3.3 x 10(-5) M and 3.6 x 10(-5) M on mushroom and murine tyrosinases, respectively. Kojic acid exhibited KEIS and KEI values of 2.4 x 10(-5) M and 2.2 x 10(-5) M on mushroom tyrosinase and those of 8.9 x 10(-5) M and 7.2 x 10(-5) M on murine tyrosinase, respectively.