Immune checkpoint inhibitors in breast cancer: development, mechanisms of resistance and potential management strategies

The use of immune checkpoint inhibitors (ICIs) has increased exponentially in the past decade, although its progress specifically for breast cancer has been modest. The first U.S. Food and Drug Administration approval for ICI in breast cancer came in 2019, eight years after the first-ever approval of an ICI. At present, current indications for ICIs are relevant only to a subset of patients with triple-negative breast cancer, or those displaying high microsatellite instability or deficiency in the mismatch repair protein pathway. With an increasing understanding of the limitations of using ICIs, which stem from breast cancer being innately poorly immunogenic, as well as the presence of various intrinsic and acquired resistance pathways, ongoing trials are evaluating different combination therapies to overcome these barriers. In this review, we aim to describe the development timeline of ICIs and resistance mechanisms limiting their utility, and summarise the available approaches and ongoing trials relevant to overcoming each resistance mechanism.

Insurance coverage gap for treatment of melasma compared to rosacea: it pays to be light

Treatments for many common dermatologic diagnoses are denied insurance coverage due to their arbitrary cosmetic classification. Melasma is one such diagnosis often considered cosmetic by payers, and since it is commonly identified in darker-skinned individuals, its cosmetic classification creates an economic barrier for patients of color. Although dermatologists have previously described insurance coverage gaps for conditions typically seen in patients of color, this coverage gap has never been quantified.¹ Thus, we investigated the rate of insurance coverage for first-line topical treatments for rosacea versus melasma. Rosacea and melasma share a number of key features - both are common, chronic, dermatological conditions that are exacerbated by sun exposure, are primarily treated topically, and cause measurably decreased quality of life in affected patients.^2,3 Rosacea, however, is often diagnosed in patients with Fitzpatrick skin types I-II, with 91.8% of rosacea diagnoses seen in white patients, while melasma is predominantly diagnosed in patients with Fitzpatrick skin types III-V.^4-6.

Locoregional relapse after gastrectomy with D2 lymphadenectomy for gastric cancer

BACKGROUND

Risk for and site of locoregional relapse have not been well studied in patients undergoing gastrectomy with D2 lymphadenectomy for gastric cancer.

METHODS

Patients who had undergone gastrectomy with D2 lymphadenectomy for gastric cancer between 2004 and 2007 were identified from an institutional database. The locoregional relapse rate was estimated by competing risk analysis, and risk groups were derived according to locoregional relapse risk using recursive partitioning analysis (RPA). The locations of nodal relapses were evaluated according to Japanese Classification of Gastric Carcinoma criteria.

RESULTS

Some 2618 patients were included. With a median follow-up of 78·0 (range 28·5-122·6) months, relapse was diagnosed in 471 of 2618 patients (18·0 per cent). The cumulative incidence of locoregional relapse at 5 years was 8·5 (95 per cent c.i. 7·4 to 9·6) per cent. The 5-year locoregional recurrence rates for high-risk (N3), intermediate-risk (N1-2) and low-risk (N0) groups were 32·4, 12·3 and 1·7 per cent respectively (P < 0·001). Among patients with regional relapse, 90·4 per cent had involvement outside the D2 dissected area, and the most commonly involved site was station 16b1. This pattern was maintained in the RPA risk groups (P = 0·329).

CONCLUSION

Locoregional relapse at 5 years after gastrectomy with D2 lymphadenectomy was 8·5 per cent, and was most often seen outside the D2 dissected area.

Emerging biomarkers for PD-1 pathway cancer therapy

The field of immuno-oncology has witnessed unprecedented success in recent years, with several PD=1 and PD-L1 inhibitors obtaining US FDA registration and breakthrough drug therapy designation in multiple tumor types. Despite its clear efficacy in certain cancers, treatment with these agents carries a risk of immune-related toxicities and substantial financial burden. It is, therefore, critical to identify patients likely to benefit from such immunotherapies and develop strategies to differentiate responders from nonresponders early during treatment. Here we discuss the development of predictive and treatment response biomarkers for immune checkpoint inhibitors. We first examine the role of PD-L1 expression, the most extensively studied predictive biomarker of response, and further discuss emerging putative predictive biomarkers. We also detail challenges faced in the development of response assessments for immunotherapeutics and propose other biomarkers that may be useful as surrogate intermediate end points of response.

Gene regulatory network identification from the yeast cell cycle based on a neuro-fuzzy system

Many studies exist for reconstructing gene regulatory networks (GRNs). In this paper, we propose a method based on an advanced neuro-fuzzy system, for gene regulatory network reconstruction from microarray time-series data. This approach uses a neural network with a weighted fuzzy function to model the relationships between genes. Fuzzy rules, which determine the regulators of genes, are very simplified through this method. Additionally, a regulator selection procedure is proposed, which extracts the exact dynamic relationship between genes, using the information obtained from the weighted fuzzy function. Time-series related features are extracted from the original data to employ the characteristics of temporal data that are useful for accurate GRN reconstruction. The microarray dataset of the yeast cell cycle was used for our study. We measured the mean squared prediction error for the efficiency of the proposed approach and evaluated the accuracy in terms of precision, sensitivity, and F-score. The proposed method outperformed the other existing approaches.

Cotunneling Drag Effect in Coulomb-Coupled Quantum Dots

In Coulomb drag, a current flowing in one conductor can induce a voltage across an adjacent conductor via the Coulomb interaction. The mechanisms yielding drag effects are not always understood, even though drag effects are sufficiently general to be seen in many low-dimensional systems. In this Letter, we observe Coulomb drag in a Coulomb-coupled double quantum dot and, through both experimental and theoretical arguments, identify cotunneling as essential to obtaining a correct qualitative understanding of the drag behavior.

Performance of a Web-based, realtime, tele-ultrasound consultation system over high-speed commercial telecommunication lines

A Web-based, realtime, tele-ultrasound consultation system was designed. The system employed ActiveX control, MPEG-4 coding of full-resolution ultrasound video (640 × 480 pixels at 30 frames/s) and H.320 videoconferencing. It could be used via a Web browser. The system was evaluated over three types of commercial line: a cable connection, ADSL and VDSL. Three radiologists assessed the quality of compressed and uncompressed ultrasound video-sequences from 16 cases (10 abnormal livers, four abnormal kidneys and two abnormal gallbladders). The radiologists' scores showed that, at a given frame rate, increasing the bit rate was associated with increasing quality; however, at a certain threshold bit rate the quality did not increase significantly. The peak signal to noise ratio (PSNR) was also measured between the compressed and uncompressed images. In most cases, the PSNR increased as the bit rate increased, and increased as the number of dropped frames increased. There was a threshold bit rate, at a given frame rate, at which the PSNR did not improve significantly. Taking into account both sets of threshold values, a bit rate of more than 0.6 Mbit/s, at 30 frames/s, is suggested as the threshold for the maintenance of diagnostic image quality.

Early menarche increases the risk of Type 2 diabetes in young and middle-aged Korean women

AIMS

To investigate the association between early menarche (menarche age < 12 years) and Type 2 diabetes mellitus in young and middle-aged Korean women.

METHODS

We analysed data for 4657 women aged 20-50 years from the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV) (2007-2009).

RESULTS

The prevalence of Type 2 diabetes was 2.8%. Women with early menarche had a higher prevalence of impaired fasting glucose than did women with later menarche (age ≥ 12 years) in the 20-30 age group (7.4% vs. 3.0%), and a higher prevalence of diabetes in the 30-40 (6.3% vs. 1.7%) and 40-50 (18.5% vs. 4.4%) age groups. The odds ratio (OR) of Type 2 diabetes in women with early menarche was 3.61 [95% confidence interval (CI), 1.90-6.88] after adjusting for age. In multivariate regression, the OR of Type 2 diabetes decreased to 2.52 (95% CI, 1.29-4.94) after further adjusting for BMI. However, the OR decreased to 2.04 (95% CI, 0.95-4.39) without significance after adjusting for HOMA-IR.

CONCLUSIONS

Early menarche increased the risk of Type 2 diabetes in young and middle-aged Korean women although adulthood adiposity attenuated the relationship. Knowledge of age at menarche is important in identifying women at risk for diabetes.

Phase I and biomarker study of OPB-51602, a novel signal transducer and activator of transcription (STAT) 3 inhibitor, in patients with refractory solid malignancies

BACKGROUND

The aim of this study was to determine the maximum-tolerated dose (MTD), safety, pharmacokinetics, and pharmacodynamics of OPB-51602, an oral, direct signal transduction activator of transcription 3 (STAT3) inhibitor, in patients with refractory solid tumors.

PATIENTS AND METHODS

Three cohorts were studied: cohort A, a sequential dose escalation of OPB-51602 administered intermittently (days 1-14 every 21 days); cohort B, an expansion cohort evaluating the dose lower than the MTD; cohort C, evaluating continuous daily dosing.

RESULTS

Fifty-one patients were studied at 2, 4, and 5 mg per day dosing. The MTD was 5 mg; first-cycle dose-limiting toxicities (DLTs) were grade 3 hyponatremia in one patient, and grade 3 dehydration in another. Intermittent dosing of both 2 and 4 mg doses were tolerable, and the recommended phase II dose was 4 mg. Cohort B investigated 4 mg intermittently, whereas cohort C investigated 4 mg continuously. Common toxicities included fatigue, nausea/vomiting, diarrhea, anorexia, and early-onset peripheral neuropathy. Drug-induced pneumonitis occurred in two patients in cohort C. Continuous dosing was associated with a higher incidence of peripheral neuropathy and a lower mean relative dose intensity, compared with intermittent dosing. Steady-state pharmacokinetics was characterized by high oral clearance, mean elimination half-life ranging from 44 to 61 h, and a large terminal-phase volume of distribution. An active metabolite, OPB-51822, accumulated to a greater extent than OPB-51602. Flow cytometry of peripheral blood mononuclear cells demonstrated pSTAT3 (Tyr(705)) inhibition following exposure. Two patients achieved partial responses at 5 mg intermittently and 4 mg continuously; both had epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC) with prior EGFR tyrosine kinase inhibitor exposure.

CONCLUSION

OPB-51602 demonstrates promising antitumor activity, particularly in NSCLC. Its long half-life and poorer tolerability of continuous dosing, compared with intermittent dosing, suggest that less frequent dosing should be explored.

CLINICALTRIALSGOV IDENTIFIER

NCT01184807.

Inborn Error of Metabolism (IEM) screening in Singapore by electrospray ionization-tandem mass spectrometry (ESI/MS/MS): An 8 year journey from pilot to current program

IEM screening by ESI/MS/MS was introduced in Singapore in 2006. There were two phases; a pilot study followed by implementation of the current program. The pilot study was over a 4 year period. During the pilot study, a total of 61,313 newborns were screened, and 20 cases of IEM were diagnosed (detection rate of 1:3065; positive predictive value (PPV) of 11%). Regular self-review, participation in external quality assessment and the Region 4 Genetic collaborative programs (http://www.region4genetics.org/) had led to the robust development of our current NBS MS/MS program. Overall, from July 2006 to April 2014, we screened a total of 177,267 newborns. The mean age at the time of sampling was 47.9h. Transportation of samples to the testing laboratory averaged 0.92 day. Upon receipt of sample, the NBS result was available within 1.64 days and within 3.8 days if a second tier test was required. Using absolute cut-off values in place of the initial 99th percentile reference range for the analyte markers and the introduction of two 2nd tier tests (MMA and Succinylacetone) had significantly reduced the high recall rate from an initial 1.5% during the period 2006-07 to 0.12% in 2013. The NBS MS/MS program was supported by a centralized confirmatory/diagnostic testing laboratory and a rapid response team of metabolic specialists. The detection rate was 1: 3165 (1:2727 if maternal conditions were also included). There were 23 newborns affected with organic acidemias (incidence: 1:6565), 23 with fatty acid oxidation disorders (incidence: 1:6565), and 10 with amino acidopathies (incidence 1:17,726). The performance metrics for the screening test were acceptable (sensitivity: 95.59%, specificity: 99.85%, PPV: 20%, FPR: 0.15). Participation in the NBS MS/MS program by hospitals was voluntary, and in 2013, the uptake rate was 71% of the annual births. We hope that newborn screening by MS/MS will become a standard of care for all babies in Singapore.

Evaluation of non-thermal effects by microwave irradiation in hydrolysis of waste-activated sludge

The activation energy (Ea) for waste-activated sludge (WAS) hydrolysis was compared between microwave irradiation (MW) and conventional heating (CH) methods to evaluate the non-thermal effect of MW. The microwave-assisted hydrolysis of WAS was assumed to follow the first-order kinetics on the basis of volatile suspended solids (VSS) conversion to soluble chemical oxygen demand (SCOD) for different initial VSS concentrations. By comparing the VSS decrement and the SCOD increment between MW and CH at different absolute temperatures of 323, 348 and 373 K, the average ratio of VSS conversion to SCOD was determined to range from 1.42 to 1.64 g SCOD/g VSS. These results corresponded to the theoretical value of 1.69 g SCOD/g VSS based on the assumption that the molecular formula of sludge was C10H19O3N. Consequently, the Ea of the MW-assisted WAS hydrolysis was much lower than that of CH for the same temperature conditions. The non-thermal effect of MW in the hydrolysis of WAS could be identified with the lower Ea than that of CH.

Changes in bone mineral density and body composition of children with well-controlled homocystinuria caused by CBS deficiency

Homocystinuria due to cystathionine β-synthase (CBS) deficiency is an inherited disorder of the metabolism of methionine. Clinical manifestations include mental retardation, dislocation of the optic lens, vascular lesions, arterial and venous thromboembolism, skeletal abnormalities, and osteoporosis. Most homocystinuria patients diagnosed in adulthood have severe osteoporosis, and homocystinuria is frequently mentioned as a cause of osteoporosis. Good control of plasma homocysteine may prevent or delay some of these complications. However, the effectiveness of bone mineral density (BMD) gain or fracture prevention has not been addressed. Here, we describe changes in BMD and body composition in 5 CBS deficiency patients who were diagnosed at young age and were managed with good metabolic control. We found that the BMD of each region was within the normal range. BMD gain was adequate and the patients had no significant change in skeletal morphology.

Risk factors for osteoporosis in long-term survivors of intracranial germ cell tumors

SUMMARY

We measured bone mineral densities in 28 intracranial germ cell tumor long-term survivors. There was the high prevalence of osteoporosis and osteopenia, 25.0% and 42.9%, respectively, and three additional risk factors, male sex, a low lean mass, and adult growth hormone replacement, were identified.

INTRODUCTION

Intracranial germ cell tumor long-term survivors (iGCTLS) have many risk factors for osteoporosis, including irradiation from cancer therapy and multiple hormone deficiencies. However, no study of bone mineral density (BMD) has been conducted in iGCTLS because these tumors are rare. The aims of this study were to evaluate the prevalence of osteoporosis and to identify risk factors associated with reduced bone mass in iGCTLS.

METHODS

We evaluated BMD and body composition of 28 iGCTLS (10.9 ± 5.2 years after cancer treatment; 13 males) using dual-energy X-ray absorptiometry. To determine risk factors, we analyzed the medical history, including the nature of the tumor, treatment modality, endocrine status, hormone replacement therapy, lifestyle, and biochemical parameters.

RESULTS

Twenty-five percent of iGCTLS were diagnosed with osteoporosis and 42.9% with osteopenia. Most males (92.3%) had low BMD. Lean mass (LM) was positively correlated with BMD in all regions of interest, and the starting age of adult growth hormone (GH) replacement was negatively correlated with the BMD Z-score at the femur neck. In logistic regression analysis, male sex and low LM were related to low BMD.

CONCLUSIONS

The iGCTLS had a high prevalence of low BMD. We found that male sex, low LM, and delayed start of adult GH replacement were risk factors for osteoporosis. Therefore, the BMD of all iGCTLS should be evaluated, and if it is low, proper management should be started early.

Hepatocellular carcinoma in patients with chronic liver disease: a comparison of gadoxetic acid-enhanced MRI and multiphasic MDCT

AIM

To compare the diagnostic performances of gadoxetic acid-enhanced magnetic resonance imaging (MRI) and multiphasic multidetector computed tomography (MDCT) in the detection of hepatocellular carcinoma (HCC) in patients with chronic liver disease.

MATERIALS AND METHODS

Institutional review board approval was obtained for this study and informed consent was obtained from all patients. Fifty-one patients (43 men, eight women; age range 32-80 years) with 73 HCCs underwent gadoxetic acid-enhanced MRI and multiphasic MDCT. Two readers independently analysed each image in three separate reading sessions. The alternative free-response receiver operating characteristic (AFROC) method was used to analyse the diagnostic accuracy. Positive and negative predictive values and sensitivity were evaluated.

RESULTS

A total of 73 HCCs were detected in 51 patients. Although not significant (p>0.05), the areas under the receiver operating characteristic curves were 0.877 and 0.850 for MDCT, 0.918 and 0.911 for dynamic MRI, and 0.905 and 0.918 for combined interpretation of dynamic and hepatobiliary phase MR images. Differences in sensitivity, specificity, and positive and negative predictive values between the readers were not statistically significant (p>0.05). Combined interpretation of dynamic and hepatobiliary phase MRI images was more useful than MDCT in the detection of HCC lesions ≤1cm in diameter for one reader (p=0.043).

CONCLUSION

Gadoxetic acid-enhanced MRI and MDCT show similar diagnostic performances for the detection of HCC in patients with chronic liver disease. However, the combined interpretation of dynamic and hepatobiliary phase MRI images may improve diagnostic accuracy in the detection of HCC lesions ≤1cm in diameter.

Inverse associations between long-term weight change and serum concentrations of persistent organic pollutants

There is emerging evidence that persistent organic pollutants (POPs) can increase the risk of various chronic diseases. As POPs mainly bioaccumulate in adipose tissue, weight change can affect serum concentrations of POPs. However, there are few population-based studies on effects of long-term weight change on serum concentrations of POPs. We examined associations between self-reported weight change over 1 year and 10 years and serum concentrations of seven POPs in 1099 adults aged ≥ 40. Serum concentrations of most POPs were higher in those with long-term weight loss, whereas they were lower in those with long-term weight gain. Adjusted correlation coefficients of each POP with weight change for 10 years were -0.23 (P < 0.01) for trans-nonachlor, -0.16 (P < 0.01) for p,p'-dichlorodiphenyldichloroethylene, and -0.21 (P < 0.01) for β-hexachlorocyclohexane, -0.16 (P < 0.01) for PCB169, -0.20 (P < 0.01) for PCB180 and -0.17 (P < 0.01) for 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin. Weight change for 1 year showed similar but weaker associations, compared with those of long-term weight changes. Although both beneficial health effects after weight loss and harmful health effects after weight gain are generally expected, changes in serum concentrations of POPs in relation to weight change may act on health in directions opposite to what we expect with weight change.

Synthesis and electrochemical properties of LiMPO4 (M = Fe, Mn, Co) nanocrystals in polyol medium

Olivine structured LiMPO4 (M = Fe, Mn, Co) was synthesized by the solvothermal process using a polyol medium of diethylene glycol (DEG) without any further heating as a post procedure. The synthesized LiMPO4 nanoparticles exhibited an average length of 200 approximately 400 nm, width of 200 approximately 300 nm, and thickness of 20 approximately 50 nm, and with well dispersed plate and rod morphologies. The Rietveld-refined X-ray diffraction (XRD) pattern of LiFePO4 exhibited a good fit with an olivine structure (space group: Pnma) and no undesirable impurity phases. The LiFePO4 nanocrystals showed a reversible capacity of 167 mAh/g, equating to a utilization efficiency of 98% of its theoretical capacity, with a good cyclability over an extended range up to 40 cycles.

Effects of substrates on biofilm formation observed by atomic force microscopy

Formation of biofilm is known to be strongly dependent on substrates including topography, materials, and chemical treatment. In this study, a variety of substrates are tested for understanding biofilm formation. Sheets of aluminum, steel, rubber, and polypropylene have been used to examine their effects on formation of Pseudomonas aeruginosa biofilm. In particular, the morphological variation, transition, and adhesiveness of biofilm were investigated through local measurement by atomic force microscopy (AFM). Mechanism of removing biofilm from adhering to substrate is also analyzed, thus the understanding of the mechanism can be potentially useful to prevent the biofilm formation. The results reveal that formation of biofilm can remain on rough surface regardless of substrates in hot water, which may easily induce extra-polymeric substances detachment from bacterial surface. By probing using AFM, local force-distance characterization of extra-cellular materials extracted from the bacteria can exhibit the progress of the biofilm formation and functional complexities.

Development of a simple and rapid immunochromatographic strip test for diarrhea-causative porcine rotavirus in swine stool

A rapid and simple immunochromatography (IC) strip test, for specific detection of porcine rotavirus (PRV) in stool specimen, was developed. Monoclonal antibodies (mAbs) to the OSU strain of PRV have been produced in mice. Among them, two hybridoma clones that generate mAb-1 and mAb-2, respectively, specific for VP6 protein of PRV, have been selected. In the IC configuration, mAb-1, one of the selected mAbs was used to the designed coat microparticles (MP), while another mAb-2 was used to fix it on the nitrocellulose membrane strip to form a result line. The control line was formed on the same membrane strip past the result line by fixing anti-mouse IgG antibody. The IC test was capable of detecting 1000 plaque-forming units of PRV/ml in less than 5min, and the binding capacity was demonstrated by specific recognition of PRV only, but not other porcine diarrhea viruses, transmissible gastroenteritis virus (TGEV) and porcine epidemic diarrhea virus (PEDV). The IC test produced positive results with all the nine PRV-positive stool specimens and negative results with five different non-PRV specimens, which were identified previously by the polymerase chain reaction (PCR) test, respectively. The results indicate an excellent concordance between the two methods, suggesting a potential application of the three combinated IC tests (PRV, TGEV and PEDV) for the on-site, rapid screening of porcine diarrhea cases.

Production of mycelia and exo-biopolymer from molasses by Cordyceps sinensis 16 in submerged culture

The molecular weight of exo-biopolymer obtained from a submerged culture of Cordyceps sinensis 16 consisted of a main unit and a subunit of 126 and 68 kDa, respectively. The optimal medium for the production of mycelia and exo-biopolymer was determined to be molasses containing 2% sucrose, 0.9% yeast extract, 0.3% K2HPO4, and 0.4% CaCl2. Using optimized medium, maximum productions of mycelia and exo-biopolymer in shake-flask culture were 54.0 g/L and 28.4 g/L, respectively. This study suggests that large-scale production of mycelia and exo-biopolymer by C. sinensis 16 is possible in submerged culture.

Intraoperative tumor localization using laparoscopic ultrasonography in laparoscopic-assisted gastrectomy

BACKGROUND

During laparoscopic-assisted gastrectomy, it is impossible to identify early gastric cancer (EGC) lesions; therefore, a precise localization technique is needed. In this study, we used laparoscopic ultrasonography (LUS) after endoscopic clipping as a method of localizing EGC and evaluated the effectiveness of this method.

METHODS

A prospective study of 17 patients who had undergone laparoscopic-assisted gastrectomy was performed. Three endoscopic clips were applied just proximal to the tumor during the preoperative endoscopy. The applied clips were detected from the serosal side of the stomach using LUS. The serosal surface of the lesion was marked with dye.

RESULTS

In all patients, endoscopic clips were applied proximal to the lesion without complications, and the applied clips were confirmed by plain abdominal radiography. The clips were successfully detected by LUS in all patients. In the resected specimen, the serosal surface, marked with dye, was always just above the clips in the anterior wall or on the anterior wall opposite the clips applied in the posterior wall. The mean detection time was 4.7 min (range, 2-8). With this procedure, two patients underwent total gastrectomy and 15 patients underwent distal subtotal gastrectomy with gastroduodenostomy or gastrojejunostomy. Histological examination confirmed that the resection margins were tumor free in all patients. There was no operative morbidity related to the LUS procedure.

CONCLUSIONS

Using LUS to detect endoscopic clips is an easy, safe, and accurate method to localize EGC lesions in laparoscopic-assisted gastrectomy.

Morphology and kinetics studies on cephalosporin C production by Cephalosporium acremonium M25 in a 30-l bioreactor using a mixture of inocula

AIMS

In this study, the relationship between morphology and cephalosporin C (CPC) production in a 30-l bioreactor culture of Cephalosporium acremonium M25 using a 3:7 seed mixture was investigated. In addition, the kinetic model was established and applied.

METHODS AND RESULTS

CPC production was performed in a 30-l bioreactor using a 3:7 seed mixture. It was recognized that a 3:7 seed mixture was able to reduce lag phase and enhance CPC production. The maximum CPC production and cell mass were 1.96 and 81.5 g l-1 respectively. Through a morphology study by observation using image analysis, it was concluded that changes of morphological features predicted the progressive production of CPC and that a morphology study could be useful in monitoring the CPC fermentation by C. acremonium M25. In the kinetics study, a kinetic model of CPC fermentation was developed and applied. The proposed model could adequately describe the fermentation of C. acremonium M25 in a 30-l bioreactor.

CONCLUSIONS

CPC productivity was improved by using a 3:7 seed mixture in a 30-1 bioreactor. The changes in morphological features showed a very similar tendency with CPC production. A kinetic model of CPC fermentation was successfully established.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of the present study suggest that the use of a 3:7 seed mixture inocula has considerable possibilities for improving CPC productivity if applied to industrial scale fermentations. Through morphology and kinetics study, the kinetic model to describe the morphological differentiation and CPC production by C. acremonium M25 was established.

Molecular cloning and characterization of Mycobacterium bovis BCG pcp gene encoding pyrrolidone carboxyl peptidase

The Mycobacterium bovis bacilli Calmette-Guerin (BCG) pcp gene that encodes the pyrrolidone carboxyl peptidase (Pcp) was cloned from a lambdagtll genomic library and sequenced. The nucleotide sequence contains a 669 bp open reading frame coding for a protein of 222 amino acid residues with a calculated molecular mass of 23,209 Da. The deduced amino acid sequence is highly homologous to the Pcps from Bacillus amyloliquefaciens, Pseudomonas fluorescens, Bacillus subtilis, Streptococcus pyogenes, and Staphylococcus aureus. A multiple sequence alignment revealed highly conserved domains. The BCG pcp gene was overexpressed in Escherichia coli. The Pcp was purified to homogeneity. The recombinant protein was further confirmed by an enzymatic assay.

Dendritic cell-tumor coculturing vaccine can induce antitumor immunity through both NK and CTL interaction

Immunization of dendritic cells (DC) pulsed with tumor antigen can activate tumor-specific cytotoxic T lymphocytes (CTL) that are responsible for protection and regression. We show here that immunization with bone marrow-derived DC cocultured with tumor cells can induce a protective immunity against challenges to viable tumor cells. In this study, we further investigated the mechanism by which the antitumor activity was induced. Immunization of mice with DC cocultured with murine colon carcinoma. CT-26 cells, augmented CTL activity against the tumor cells. Concomitantly, an increase in natural killer (NK) cell activity was also detected in the same mice. When DC were fixed with paraformaldehyde prior to coculturing with tumor cells, most of the CTL and NK cell activity diminished, indicating that DC are involved in the process of presenting the tumor antigen(s) to CTL. NK cell depletion in vivo produced markedly low tumor-specific CTL activity responsible for tumor prevention. In addition, RT-PCR analysis confirmed the high expression of INF-gamma mRNA in splenocytes after vaccination with DC cocultured with tumors, but low expression in splenocytes from NK-depleted mice. Most importantly, the tumor protective effect rendered to DC by the coculturing with CT-26 cells was not observed in NK-depleted mice, which suggests that DC can induce an antitumor immune response by enhancing NK cell-dependent CTL activation. Collectively, our results indicate that NK cells are required during the priming of cytotoxic T-cell response by DC-based tumor vaccine and seem to delineate a mechanism by which DC vaccine can provide the desired immunity.

Apoptosis-linked gene 2 binds to the death domain of Fas and dissociates from Fas during Fas-mediated apoptosis in Jurkat cells

Apoptosis-linked gene 2 (ALG-2) is a member of the family of Ca(2+)-binding proteins with penta-EF-hand and is essential for the execution of apoptosis by various signals including Fas activation. We studied the regulation of ALG-2 during Fas-mediated apoptosis in Jurkat cells. The 22-kDa ALG-2 protein is cleaved and becomes a 19-kDa protein after Fas activation. The appearance of 19-kDa ALG-2 protein increases for 4 h after treatment with 200 ng/ml of anti-Fas Ab treatment and gradually degrades afterward. Confocal microscopic analysis showed that ALG-2 translocated from the plasma membrane to the cytosol during Fas-mediated apoptosis. Therefore, we examined if ALG-2 interacts with Fas. The protein-protein interaction of ALG-2 with Fas was demonstrated using yeast two-hybrid assays as well as in vitro GST pull-down assay. Endogenous ALG-2 was immunoprecipitated with anti-Fas Ab in Jurkat cells without Fas activation. However, the endogenous ALG-2 was no longer immunoprecipitated with anti-Fas Ab 2 h after anti-Fas Ab treatment. This study, for the first time, presents a direct molecular connection of ALG-2 to apoptosis by its direct interaction with Fas, and enlists ALG-2 as a new member of posttranslationally modified proteins during Fas-mediated apoptotic process.

A comparative study of quantitative structure activity relationship methods based on antitumor diarylsulfonylureas

A series of 28 diarylsulfonylureas with antitumor activity was subjected to a three-dimensional quantitative activity relationship (3D-QSAR) study. Three different QSAR methods, comparative molecular field analysis (CoMFA), hologram QSAR (HQSAR) and comparative molecular similarity indices analysis (CoMSIA), were compared in terms of their potential for predictability. All three QSAR-based models had good predictability and yielded q(2) values 0.74, 0.63 and 0.72, respectively. The CoMFA model provided the highest q(2) and r(2) values, which implied the significance of correlation of steric and electrostatic fields with biological activities. The number of components was 3-4 for all three QSAR methods. The quality of HQSAR or CoMSIA was slightly lower than that of CoNFA in terms of q(2) and r(2) values. HQSAR does not require the generation of a three-dimensional structure of molecules and CoMSIA does not require molecular superposition, therefore they are faster than CoMFA in data processing.

Inhibitory effect of retinoic acid on expression of inducible nitric oxide synthase gene in l929 cells

Inflammation has been known to be associated with excess synthesis of nitric oxide (NO) by inducible NO synthase (iNOS). Retinoids have been reported to have anti-inflammatory activity, but the mechanism by which they can elicit this activity is poorly understood. The effects of retinoids on NO synthesis and iNOS gene expression in murine fibroblast L929 cells were examined. Treatment of the cells with interferon-y resulted in excess NO synthesis and iNOS gene expression. All-trans-retinoic acid significantly inhibited NO synthesis and iNOS gene expression in a dose-dependent manner. Similarly, 9-cis-retinoic acid also inhibited NO synthesis, but retinol did not show any inhibitory effect on NO synthesis. These findings suggest that the modulation of iNOS gene expression is another possible pathway by which retinoids may function as anti-inflammatory agents.

Enhancement of cephalosporin C production by cultivation of Cephalosporium acremonium M25 using a mixture of inocula

AIMS

To enhance the productivity of Cephalosporin C (CPC) by cultivation of Cephalosporium acremonium M25 using a mixture of inocula.

METHODS AND RESULTS

Inoculum age was classified into three stages (early, intermediate and late) by image analysis. A mixture of inocula, according to the inoculum ages, was used for efficient production of CPC in the main culture. The most effective mixing ratio of inocula for CPC production in shake flasks was a 3 : 7 volume ratio of early- and late-stage inocula. This was also the case in a 1.5 l stirred-tank reactor. CPC productivity was enhanced by about 32% and 34% when using an inoculum mixture in the shake flask and 1.5 l stirred-tank reactor, respectively.

CONCLUSION

The morphological characteristics of C. acremonium M25 in the seed culture were quite different according to inoculum age. The compromise of different ages of inoculum showed better production of CPC.

SIGNIFICANCE AND IMPACT OF THE STUDY

The productivity of CPC was enhanced considerably when using mixed inocula. The results of this study can be applied to fungal cultures for efficient production of various metabolites.

Immunogenicity of the E1E2 proteins of hepatitis C virus expressed by recombinant adenoviruses

The E1 and E2 proteins of hepatitis C virus (HCV) are believed to be the viral envelope glycoproteins that are major candidate antigens for HCV vaccine development. We reported previously that the replication-competent recombinant adenovirus encoding core-E1-E2 genes of HCV (Ad/HCV) produces serologically reactive E1 and E2 proteins forming a heterodimer in substantial amounts. Here, we examined immunogenicity of the E1E2 proteins copurified from HeLa cells infected with Ad/HCV virus in mice. Furthermore, we constructed a replication-defective recombinant adenovirus encoding the core-E1-E2 genes of HCV (Ad.CMV.HCV) and examined immunogenicity of the virus in mice. The mice immunized intraperitoneally with the copurified E1E2 proteins induced mainly antibodies to E2, but not to E1 by Western blot analysis. The sera of mice immunized with the E1E2 inhibited the binding of E2 protein to the major extracellular loop of human CD81. E2-specific cytotoxic T cells (CTLs), but not antibodies to the E1E2 antigens were induced in the mice intramuscularly immunized with Ad.CMV.HCV virus. When immunized with both Ad.CMV.HCV virus and the E1E2, mice elicited E2-specific CTLs and antibodies to the E1E2 antigens. The results suggest that immunization of Ad.CMV.HCV virus combined with E2 protein is an effective modality to induce humoral as well as cellular immune response to E2 antigen.

Inhibition of glucocorticoid-mediated, caspase-independent dendritic cell death by CD40 activation

Glucocorticoids (GC) are potent anti-inflammatory and immunosuppressive agents that act on a variety of immune cells, including T cells, monocytes/macrophages, osteoclasts, and dendritic cells (DC). However, the mechanism(s) by which GC exert anti-inflammatory effects is still largely unknown. It is already well known that GC treatment inhibits DC maturation and interleukin (IL)-12 production by DC. In this study, we investigated the apoptosis induction of DC by a synthetic GC, dexamethasone (Dex). The stimulation with Dex resulted in DC apoptosis in a dose- and time-dependent manner as it was measured by determining annexin V-positive cells and mitochondrial potential. In contrast, monocytes that are precursor cells of DC are resistant to Dex-mediated apoptosis. The Dex-induced apoptosis of DC was independent of caspase activation because it was not inhibited by the broad caspase inhibitor, Z-VAD-fmk. It is interesting that agonistic CD40 antibody completely inhibited Dex-induced cell death, whereas other inflammatory stimuli did not show the same effect, suggesting that CD40 signaling may selectively modulate GC-mediated DC apoptosis. Taken together, our findings revealed an important role of GC and CD40 signaling in the regulation of immune responses in which DC play a key role in the inflammatory process of various immunomediated diseases.

Carbofuran suppresses T-cell-mediated immune responses by the suppression of T-cell responsiveness, the differential inhibition of cytokine production, and NO production in macrophages

The effects of carbofuran (2,3-dihydro-2,2-dimethyl-7-benzo-furanol N-methylcarbamate) on the functions of T cells in splenocytes and peritoneal macrophages were examined in view of T-cell-mediated immune response (CMIR) in male C57BL/6 mice. Intraperitoneal administration of carbofuran (0.075, 0.15 and 0.3 mg/kg body weight) resulted in significant suppression of delayed type hypersensitivity (DTH), indicating that it caused the suppression of CMIR. Carbofuran decreased Concanavalin A (Con A)- and alloantigen-induced proliferation, and interleukin (IL)-2 production of splenocytes. In vitro addition of rIL-2 could not completely restore the suppressed T-cell proliferation, and IL-2-induced proliferation of Con A-activated splenocytes was also suppressed, which implied that carbofuran caused defects in IL-2 production and responsiveness of splenocytes to IL-2, leading to the suppression of T-cell proliferation. Con A-induced production of interferon-gamma (IFN-gamma) was significantly suppressed by carbofuran, while that of IL-4 was not affected. The production of transforming growth factor-beta from splenocytes was also significantly inhibited by carbofuran. Judging from these results, carbofuran might directly suppress the cytokine production in T helper 1 (Th1) cells. In addition, IFN-gamma-induced production of nitric oxide (NO) in macrophages was also inhibited by carbofuran, which might be one of the important mechanisms of carbofuran-induced CMIR suppression in mice. Collectively, the present study suggests that carbofuran might suppress CMIR through the suppression of T-cell responsiveness, IFN-gamma production in Th1 cells, and NO generation in macrophages.

Evaluation of porous ceramic as microbial carrier of biofilter to remove toluene vapor

Three kinds of porous ceramic microbe media are fabricated from fly ash, diatomite and a mixture of fly ash and diatomite powders. Water holding capacity, density, porosity, pore size and distribution, compressive strength and micro-structure of each of the fabricated media are measured and compared. The fly ash and diatomite mixture ceramic is evaluated as the best biofilter medium among the three media because of its high compressive strength. It is selected as an experimental biofilter medium inoculated with thickened activated sludge. The laboratory scale biofilter was operated for 42 days under various experimental conditions varying in inlet toluene concentration and flow rate of contaminated air stream. The experimental result shows that the removal efficiency reaches up to 96.6% after 4 days from the start-up. Nutrient limitation is considered as a major factor limiting biofilter efficiency. Biofilter efficiency decreases substantially at the build-up of backpressure, which is largely due to the accumulation of excess VSS within the media. Periodic backwashing of the biofilter is necessary to remove excess biomass and attain stable long-term high removal efficiency. The bed needs to be backwashed when the overall pressure drop becomes greater than 460.6 Pa at space velocity of 100 h-1. A maximum flow rate of 444.85 g m-3hr-1 of toluene elimination by the mixture ceramic biofilter, which is higher than the previously reported values. This indicates that the fly ash and diatomite mixture ceramic biofilter can be effectively applied for removing toluene vapor.

Neonatal footshock stress alters adult behavior and hippocampal corticosteroid receptors

To determine the effects of stress early in life on adult behavior and hippocampal corticosteroid receptors, rats were exposed to footshocks (0.8 mA, 60 times/day, randomly apart) on postnatal days 14, 17 and 20. When they reached 6 months of age, neurobehavioral alterations were measured. The footshock-experienced rats learned more rapidly in the autoshaped learning test than similarly handled controls. They also stabilized more quickly after exposure to a novel environment than the handled controls, but only at the same rate as animals which had not been handled except for weighing. The density of [3H]dexamethasone binding sites increased and that of [3H]corticosterone binding sites decreased in the hippocampi of these rats. These results indicate that early life stress results in altered behavior and hippocampal corticosteroid receptors at adulthood, and suggest that the mineralocorticoid and the glucocorticoid receptors are differentially regulated by early life stress.

Protective antitumor activity through dendritic cell immunization is mediated by NK cell as well as CTL activation

Dendritic cells (DCs) are potent professional antigen-presenting cells (APC) capable of inducing the primary T cell response to antigen. Although tumor cells express target antigens, they are incapable of stimulating a tumor-specific immune response due to a defect in the costimulatory signal that is required for optimal activation of T cells. In this work, we describe a new approach using tumor-DC coculture to improve the antigen presenting capacity of tumor cells, which does not require a source of tumor-associated antigen. Immunization of a weakly immunogenic and progressive tumor cocultured with bone marrow-derived DCs generated an effective tumor vaccine. Immunization with the cocultured DCs was able to induce complete protective immunity against tumor challenges and was effective for the induction of tumor-specific CTL (cytotoxic T lymphocyte) activity. Furthermore, high NK cell activity was observed in mice in which tumors were rejected. In addition, immunization with tumor-pulsed DCs induced delayed tumor growth, but not tumor eradication in tumor-bearing mice. Our results demonstrate that coculture of DCs with tumors generated antitumor immunity due to the NK cell activation as well as tumor-specific T cell. This approach would be useful for designing tumor vaccines using DCs when the information about tumor antigens is limited.

Enhanced antigen-presenting activity and tumour necrosis factor-alpha-independent activation of dendritic cells following treatment with Mycobacterium bovis bacillus Calmette-Guérin

Dendritic cells (DCs) are most potent among the antigen-presenting cells and are believed to be crucial for the initiation of a primary T-cell response to foreign antigens. Mycobacterial infection within macrophages is controlled by cell-mediated immunity. To elucidate the stimulation of immune response by Mycobacterium bovis bacillus Calmette-Guérin (BCG), we purified DCs from precursor cells in human peripheral blood mononuclear cells (PBMC) by culturing them with granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4) and characterized their surface antigen expression. The interaction of cultured DCs with BCG resulted in increased surface expression of several DC-related marker antigens. BCG also induced reduction of endocytosis, enhancement of CD83 expression as well as B7 costimulatory molecules and IL-12 production, suggesting that BCG treatment directly induces DCs to mature. BCG-treated DCs were much more potent antigen-presenting cells in allogeneic immune response than untreated DCs. Moreover, while the neutralization of tumour necrosis factor-alpha (TNF-alpha) significantly blocked the DC maturation induced by lipopolysaccharide (LPS), it could not inhibit the induction of DC maturation by the BCG treatment, indicating that TNF-alpha production plays a minor role in the BCG-induced DC maturation. However, the neutralization of TNF-alpha resulted in decreased IL-12 production by activated DCs. These results suggest that infection with BCG might evoke direct activation and maturation of DC and the general immune stimulant effect of BCG might be related with the activation of DCs.

Wet decontamination-induced stratum corneum hydration--effects on the skin barrier function to diethylmalonate

Decontamination of chemical agents from the skin uses both dry and wet decontamination processes. Recent studies have shown that wet decontamination frequently results in stratum corneum hydration. To evaluate the hydration effect of wet decontamination on the skin barrier function and hence on the decontamination efficiency, a series of comparative studies were carried out on human skin contaminated with the nerve agent simulant diethylmalonate, using decontamination media having different salinity and surfactants. The results showed that, compared to non-decontaminated skin, remnant diethylmalonate on decontaminated skin penetrated at an accelerated rate in the immediate 2 h following decontamination. This transient enhancement effect, ranging from 20 to 98%, was depended on the nature of the decontamination media used and was more obvious in skin samples that were decontaminated 1 h postexposure. All decontamination media exhibited this effect, with the greatest enhancement observed in the following order: anionic surfactant > cationic surfactant > non-ionic surfactant > deionized water > 0.9% saline > 9% saline.

Induction of cytotoxic T lymphocytes with peptides in vitro: identification of candidate T-cell epitopes in hepatitis B virus X antigen

Cytotoxic T lymphocytes (CTL) have been suggested to contribute to viral clearance during hepatitis B virus (HBV) infection. To induce effective CTL against viral infection by peptide vaccination, it is essential to identify the epitope peptides recognized by CTL. Here, 15 peptide sequences that contain HLA-A2.1-restricted CTL binding consensus motif were identified on hepatitis B virus X (HBx) protein and synthesized for further characterization. In the binding assay, 8 of 15 synthetic peptides enhanced the expression of HLA-A2.1 molecules on the surface of T2 cells, a human transport-associated antigen processing-deficient cell line. This result implies that these eight peptides are able to bind to the HLA-A2.1 molecules. These peptides were further tested for their ability to activate CTL from peripheral blood mononuclear cells (PBMCs) isolated from HBV chronic carriers. Five of eight tested peptides activated PBMC-derived T cells, resulting in the lysis of the target T2 cells pulsed with the same peptide. Furthermore, the CTL responses to HBx antigen in HBV chronic carriers were shown to be polyclonal, multispecific, and mediated mainly by CD8+ T cells. In contrast, these responses were not detected in uninfected healthy blood donors. Although the five CTL epitope peptides identified in this study have not been proven to be the naturally processed epitopes in HBV-infected hepatocytes, they could be candidates for peptide-based immunotherapy against HBV infection.

Primary amyloidosis presenting as a nasopharyngeal mass

Amyloid is defined as a pathologic proteinaceous substance which, when deposited between the cells of tissues and organs, leads to various clinical conditions. Immunohistochemistry has allowed for better classification and understanding of the pathophysiology of amyloidosis. In the upper aerodigestive tract, amyloidosis is a rare condition occurring most frequently in the larynx. We present the case of a 42-year-old woman with complete nasal obstruction due to primary nasopharyngeal amyloidosis. This represents the first reported case of primary nasopharyngeal amyloidosis containing both the lambda and kappa immunoglobulin light chains. The clinical and radiologic findings, as well as the management of primary amyloidosis of the upper aerodigestive tract, will be discussed. A review of the literature pertaining to nasal and nasopharyngeal amyloidosis will be presented.

Effects of exposure conditions to footshocks early in life on spontaneous locomotor activity at maturity in rats

Both genetic and environmental factors are involved in establishing a behavior. An animal study was done to determine the characteristics of interaction between genetic (nature) and environmental (nurture) factors. Delivery of footshocks (0.8 mA x 60 times, at random) early in life was used as the environmental stimulus. As the footshock was delivered repeatedly, a rat showed helplessness behavior and the number of shocks necessary to elicit helplessness was measured to quantify the trait of an animal in coping with the aversive environmental stimulus. The nocturnal ambulatory activity at adulthood was measured as a behavioral expression of the nature-nurture interaction. Although the experience of footshocks early in life did not significantly alter average activity levels at adulthood, the activity was positively correlated with the number of shocks necessary to elicit helplessness (nature) while receiving footshocks (nurture) on postnatal day 14. Additionally, a second exposure to identical shock parameters on postnatal day 21 reversed the relationship. These results clearly showed that an interaction between nature and nurture during infancy leads to substantial behavioral alterations later in life, and suggest that the nature-dependent determination of an adult behavior can be modified in different directions by the conditions of an environmental experience early in life.

Isolation and characterization of cDNA clone for human liver 10-formyltetrahydrofolate dehydrogenase

A cDNA clone encoding 10-formyltetrahydrofolate dehydrogenase (10-FTHFDH) was isolated from a human fetal liver cDNA library. It contained the open reading frame of 2,709 base pairs and predicted a protein comprising 902 amino acids with a calculated molecular weight of 98,700 Da. The deduced protein showed about 93.6% homology (90.5% identity, 3.1% favored substitutions) when compared with rat 10-FTHFDH. The distribution of 10-FTHFDH transcript in various human tissues was studied by Northern blot analysis using poly(A+) RNAs from different tissues. The 10-FTHFDH transcript with an approximate size of 2.7 kb was mainly expressed in human kidney, skeletal muscle, and liver and rarely expressed in other tissues.

Cloning of the genomic sequence encoding a processed adenylate kinase 2 pseudogene

A chromosomal DNA sequence harboring a processed AK2B pseudogene was isolated from a human genomic library. It was a variant of the AK2B gene sequence including several point mutations, deletions, and insertions. The nucleotide sequence of the ORF of the AK2B pseudogene predicted a truncated form of the AK2B mutant suggesting that the processed pseudogene is nonfunctional. A repetitive sequence, AAAAGAGAG, found in the 5' and 3' flanking regions of the pseudogene and the poly(A) tract in the 3' end junction suggest that a mRNA of AK2B may have been converted to the processed pseudogene by retrotransposition events. Previously, it was suggested that an adenylate kinase (AK) 2 related gene on chromosome 2, confirmed by Southern analysis using somatic cell hybrid cell lines, may be a processed pseudogene. It is proposed that the processed pseudogene isolated in this study may be the AK2 related nonfunctional gene localized on human chromosomes 2.

Crossed cerebellar diaschisis due to intracranial hematoma in basal ganglia or thalamus

The purpose of our study was to evaluate the remote effects on the cerebellum and cerebral cortex from subcortical hematoma without cortical structural abnormality.

METHODS

Our study included 23 patients with hematoma, strictly confined either to the basal ganglia (n = 12) or thalamus (n = 11) without cortical abnormality on CT or MRI. Twenty psychiatric patients without structural abnormality on MRI were selected as control subjects. Technetium-ethyl cysteinate dimer brain SPECT was performed in patients and control subjects. Regional cerebral blood flow (rCBF) was visually and semiquantitatively assessed. Asymmetry index (AI) was determined using data from regions of interest at the basal ganglia, thalamus, cerebellum, frontal, parietal and temporal cortex to support the semiquantitative analysis. The criteria for defining hypoperfusion that reflected diaschisis was based on an AI > the mean + 2 s.d. of AI in control subjects.

RESULTS

In the basal ganglia hematoma, rCBF was reduced significantly in the contralateral cerebellum (10/12), ipsilateral thalamus (12/12), ipsilateral frontal (6/12), parietal (12/12) and temporal cortex (10/12). As for thalamic hematoma, significantly reduced perfusion was seen in the contralateral cerebellum (10/11), ipsilateral basal ganglia (7/11), ipsilateral frontal (5/11), parietal (11/ 11) and temporal cortex (3/11).

CONCLUSION

Crossed cerebellar diaschisis (CCD) and cortical diaschisis frequently were observed in patients with subcortical hematoma without cortical structural abnormality. This suggested that CCD can develop regardless of interruption of the corticopontocerebellar tract, which is the principal pathway of CCD.

A simple method for the removal of epithelium grown beneath the hinge after LASIK

The purpose of this study is to demonstrate a method of how to remove epithelium grown beneath the hinge area after laser in situ keratomileusis (LASIK) without affecting the refractive part of the lenticule. In three cases, an incision was made at the base of the hinge by RK diamond knife to free the lenticule from the stroma. The lenticule was lifted from the nasal edge. The epithelium grown along the interface beneath the hinge area was removed with a Bard-Parker No. 15 knife. The lenticular flap was repositioned with interrupted sutures using 10-0 nylon. No further epithelial ingrowth was observed. The central cornea remained clear leaving a peripheral ring-shaped opacity without affecting the preoperative naked visual acuity. In conclusion, epithelial ingrowth along the interface after LASIK can be removed safely without affecting the refractive part by the incision of the hinge area with a RK diamond knife, removal of the epithelium, and suturing of the lenticule to the stromal bed.