Prognostic implication of residual inflammatory risk according to disease status in patients treated with percutaneous coronary intervention

Background

Compared with stable angina, acute myocardial infarction (AMI) phenotype is related with the elevated inflammatory activity. However, time-dependent change of inflammatory level and its prognostic implication has not been fully understood according to the disease entity.

Methods

We enrolled total 4,263 patients who underwent percutaneous coronary intervention (PCI) with serial measurement of high-sensitivity C-reactive protein (hsCRP) at on-admission and 1-month post-PCI. The risks of MACE (a composite of death, MI or stroke), and major bleeding were evaluated up to 4 years after procedure.

Results

Compared with the non-AMI group (n=1,887), the AMI group (n=2,376) showed the significant decrease of hs-CRP during 1 month (∇0.5 vs. ∇0.1 mg/L; P<0.001). However, 1-month hs-CRP value still was higher in the AMI group than in the non-AMI group (median: 1.0 vs. 0.9 mg/L; P=0.001). During 1-month follow-up, high vs. low inflammatory risk (upper vs. lower tertile of hs-CRP) was significantly associated with increased rate of MACE in the AMI group (HR: 7.66; 95% CI: 2.29–25.59; P<0.001), but not in the non-AMI group (HR: 0.74; 95% CI: 0.12–4.40; P=0.736). From 1-month to 4-years, patients with high inflammatory risk showed the greater rate of MACE compared to those with low inflammatory risk, in both the AMI (HR: 2.40; 95% CI: 1.73–3.45; P<0.001) and non-AMI (HR: 2.67; 95% CI: 1.80–3.94; P<0.001) groups.

Conclusion

In PCI-treated patients, patients presented with AMI showed the greater values of inflammatory activity and its prognostic implication during the early phase, but combined inflammatory risk appeared similar across the disease entity during the late phase. This result may support that clinical benefit of post-PCI anti-inflammatory treatment would be constant regardless of the disease entity during the stabilized phase.

Funding Acknowledgement

Type of funding sources: None.

MRI Features May Predict Molecular Features of Glioblastoma in Isocitrate Dehydrogenase Wild-Type Lower-Grade Gliomas

BACKGROUND AND PURPOSE

Isocitrate dehydrogenase (IDH) wild-type lower-grade gliomas (histologic grades II and III) with epidermal growth factor receptor (EGFR) amplification or telomerase reverse transcriptase (TERT) promoter mutation are reported to behave similar to glioblastoma. We aimed to evaluate whether MR imaging features could identify a subset of IDH wild-type lower-grade gliomas that carry molecular features of glioblastoma.

MATERIALS AND METHODS

In this multi-institutional retrospective study, pathologically confirmed IDH wild-type lower-grade gliomas from 2 tertiary institutions and The Cancer Genome Atlas constituted the training set (institution 1 and The Cancer Genome Atlas, 64 patients) and the independent test set (institution 2, 57 patients). Preoperative MRIs were analyzed using the Visually AcceSAble Rembrandt Images and radiomics. The molecular glioblastoma status was determined on the basis of the presence of EGFR amplification and TERT promoter mutation. Molecular glioblastoma was present in 73.4% and 56.1% in the training and test sets, respectively. Models using clinical, Visually AcceSAble Rembrandt Images, and radiomic features were built to predict the molecular glioblastoma status in the training set; then they were validated in the test set.

RESULTS

In the test set, a model using both Visually AcceSAble Rembrandt Images and radiomic features showed superior predictive performance (area under the curve = 0.854) than that with only clinical features or Visually AcceSAble Rembrandt Images (areas under the curve = 0.514 and 0.648, respectively; P < . 001, both). When both Visually AcceSAble Rembrandt Images and radiomics were added to clinical features, the predictive performance significantly increased (areas under the curve = 0.514 versus 0.863, P < .001).

CONCLUSIONS

MR imaging features integrated with machine learning classifiers may predict a subset of IDH wild-type lower-grade gliomas that carry molecular features of glioblastoma.

Ultrafast Transient Spectroscopy of Trans-Polyacetylene in the Midinfrared Spectral Range

Trans-polyacetylene [t-(CH)_{x}] possesses twofold ground state degeneracy. Using the Su-Schrieffer-Heeger Hamiltonian, scientists predicted charged solitons to be the primary photoexcitations in t-(CH)_{x}; this prediction, however, has led to sharp debate. To resolve this saga, we use subpicosecond transient photomodulation spectroscopy in the mid-IR spectral range (0.1-1.5 eV) in neat t-(CH)_{x} thin films. We show that odd-parity singlet excitons are the primary photoexcitations in t-(CH)_{x}, similar to many other nondegenerate π-conjugated polymers. The exciton transitions are characterized by two photoinduced absorption (PA) bands at 0.38 and 0.6 eV, and an associated photoluminescence band at ∼1.5  eV having similar polarization memory. The primary excitons undergo internal conversion within ∼100  fs to an even-parity (dark) singlet exciton with a PA band at ∼1.4  eV. We also find ultrafast photogeneration of charge polarons when pumping deep into the polymer continuum band, which are characterized by two other PA bands in the mid-IR and associated photoinduced IR vibrational modes.

Whole-Tumor Histogram and Texture Analyses of DTI for Evaluation of IDH1-Mutation and 1p/19q-Codeletion Status in World Health Organization Grade II Gliomas

BACKGROUND AND PURPOSE

Prediction of the isocitrate dehydrogenase 1 (IDH1)-mutation and 1p/19q-codeletion status of World Health Organization grade ll gliomas preoperatively may assist in predicting prognosis and planning treatment strategies. Our aim was to characterize the histogram and texture analyses of apparent diffusion coefficient and fractional anisotropy maps to determine IDH1-mutation and 1p/19q-codeletion status in World Health Organization grade II gliomas.

MATERIALS AND METHODS

Ninety-three patients with World Health Organization grade II gliomas with known IDH1-mutation and 1p/19q-codeletion status (18 IDH1 wild-type, 45 IDH1 mutant and no 1p/19q codeletion, 30 IDH1-mutant and 1p/19q codeleted tumors) underwent DTI. ROIs were drawn on every section of the T2-weighted images and transferred to the ADC and the fractional anisotropy maps to derive volume-based data of the entire tumor. Histogram and texture analyses were correlated with the IDH1-mutation and 1p/19q-codeletion status. The predictive powers of imaging features for IDH1 wild-type tumors and 1p/19q-codeletion status in IDH1-mutant subgroups were evaluated using the least absolute shrinkage and selection operator.

RESULTS

Various histogram and texture parameters differed significantly according to IDH1-mutation and 1p/19q-codeletion status. The skewness and energy of ADC, 10th and 25th percentiles, and correlation of fractional anisotropy were independent predictors of an IDH1 wild-type in the least absolute shrinkage and selection operator. The area under the receiver operating curve for the prediction model was 0.853. The skewness and cluster shade of ADC, energy, and correlation of fractional anisotropy were independent predictors of a 1p/19q codeletion in IDH1-mutant tumors in the least absolute shrinkage and selection operator. The area under the receiver operating curve was 0.807.

CONCLUSIONS

Whole-tumor histogram and texture features of the ADC and fractional anisotropy maps are useful for predicting the IDH1-mutation and 1p/19q-codeletion status in World Health Organization grade II gliomas.

Prediction of IDH1-Mutation and 1p/19q-Codeletion Status Using Preoperative MR Imaging Phenotypes in Lower Grade Gliomas

BACKGROUND AND PURPOSE

WHO grade II gliomas are divided into three classes: isocitrate dehydrogenase (IDH)-wildtype, IDH-mutant and no 1p/19q codeletion, and IDH-mutant and 1p/19q-codeleted. Different molecular subtypes have been reported to have prognostic differences and different chemosensitivity. Our aim was to evaluate the predictive value of imaging phenotypes assessed with the Visually AcceSAble Rembrandt Images lexicon for molecular classification of lower grade gliomas.

MATERIALS AND METHODS

MR imaging scans of 175 patients with lower grade gliomas with known IDH1 mutation and 1p/19q-codeletion status were included (78 grade II and 97 grade III) in the discovery set. MR imaging features were reviewed by using Visually AcceSAble Rembrandt Images (VASARI); their associations with molecular markers were assessed. The predictive power of imaging features for IDH1-wild type tumors was evaluated using the Least Absolute Shrinkage and Selection Operator. We tested the model in a validation set (40 subjects).

RESULTS

Various imaging features were significantly different according to IDH1 mutation. Nonlobar location, larger proportion of enhancing tumors, multifocal/multicentric distribution, and poor definition of nonenhancing margins were independent predictors of an IDH1 wild type according to the Least Absolute Shrinkage and Selection Operator. The areas under the curve for the prediction model were 0.859 and 0.778 in the discovery and validation sets, respectively. The IDH1-mutant, 1p/19q-codeleted group frequently had mixed/restricted diffusion characteristics and showed more pial invasion compared with the IDH1-mutant, no codeletion group.

CONCLUSIONS

Preoperative MR imaging phenotypes are different according to the molecular markers of lower grade gliomas, and they may be helpful in predicting the IDH1-mutation status.

Risk factors to predict the development of chronic kidney disease in patients with lupus nephritis

Objectives

We analyzed the clinical follow-up results of 88 lupus nephritis patients to find prognostic factors for the development of chronic kidney disease in ethnically homogeneous Korean patients with biopsy-proven lupus nephritis.

Methods

Sociodemographic, clinical, laboratory, and treatment-related data at the time of kidney biopsy and during follow-up were obtained. Renal biopsy specimens were reclassified according to the International Society of Pathology/Renal Pathology Society classification, separately, by two renal pathologists blinded to the previous classification. Univariate and multivariate analyses were performed using the Cox proportional hazard regression model to identify independent risk factors for chronic kidney disease in lupus nephritis patients.

Results

Eighteen of 88 patients (20.5%) developed chronic kidney disease during a mean follow-up of 47.6 months (range: 12–96 months). Patients who developed chronic kidney disease were older at onset of lupus nephritis, had less education, and were more likely to have hypertension; they had lower serum albumin levels, lower platelet levels, higher serum creatinine levels, lower estimated glomerular filtration rate, higher chronicity index, and lower frequency of anti-ribosomal P antibodies, and they were less likely to be in complete remission in the first year. In stepwise multivariable analyses, hypertension, lower glomerular filtration rate, and failure to achieve complete remission in the first year of treatment were significant predictors of the development of chronic kidney disease in lupus nephritis patients.

Conclusions

These findings suggest that patients with hypertension and decreased kidney function at the onset of lupus nephritis and showing a poor response to immunosuppressive drugs in the first year should be monitored carefully and managed aggressively to avoid deterioration of kidney function.

The rate of and risk factors for frequent hospitalization in systemic lupus erythematosus: results from the Korean lupus network registry

Objectives The survival rate of patients with systemic lupus erythematosus has improved in the last few decades, but the rate of hospitalization and health care costs for these patients remain higher than in the general population. Thus, we evaluated the rate of hospitalization and associated risk factors in an inception cohort of Korean patients with lupus. Methods Of the 507 patients with systemic lupus erythematosus enrolled in the KORean lupus NETwork, we investigated an inception cohort consisting of 196 patients with systemic lupus erythematosus presenting within 6 months of diagnosis based on the American College of Rheumatology classification criteria. We evaluated the causes of hospitalization, demographic characteristics, and laboratory and clinical data at the time of systemic lupus erythematosus diagnosis of hospitalized patients and during a follow-up period. We calculated the hospitalization rate as the number of total hospitalizations divided by the disease duration, and defined "frequent hospitalization" as hospitalization more than once per year. Results Of the 196 patients, 117 (59.6%) were admitted to hospital a total of 257 times during the 8-year follow-up period. Moreover, 22 (11.2%) patients were hospitalized frequently. The most common reasons for hospitalization included disease flares, infection, and pregnancy-related morbidity. In the univariate regression analysis, malar rash, arthritis, pericarditis, renal involvement, fever, systemic lupus erythematosus disease activity index > 12, hemoglobin level < 10 mg/dl, albumin level < 3.5 mg/dl, and anti-Sjögren's syndrome A positivity were associated with frequent hospitalization. Finally, multivariate analysis showed that arthritis, pericarditis, and anti-Sjögren's syndrome A antibody positivity at the time of diagnosis were risk factors for frequent hospitalization. Conclusions Our results showed that frequent hospitalization occurred in 11.2% of hospitalized patients and arthritis, pericarditis, and anti-Sjögren's syndrome A antibody positivity at the time of diagnosis were risk factors for frequent hospitalization.

Microporous carbon nanosheets with redox-active heteroatoms for pseudocapacitive charge storage

We report microporous carbon nanosheets containing numerous redox active heteroatoms fabricated from exfoliated waste coffee grounds by simple heating with KOH for pseudocapacitive charge storage. We found that various heteroatom combinations in carbonaceous materials can be a redox host for lithium ion storage. The bio-inspired nanomaterials had unique characteristics, showing superior electrochemical performances as cathode for asymmetric pseudocapacitors.

HbA1c for diagnosis and prognosis of gestational diabetes mellitus

AIMS

HbA1c is a widely used marker in diagnosing type 2 diabetes mellitus (DM), but its clinical utility in diagnosing gestational diabetes mellitus (GDM) is not established. Here, we evaluated the clinical usefulness of HbA1c in diagnosing GDM and predicting the risk of future type 2 DM development among GDM patients.

METHODS

This retrospective, cross-sectional study included 321 subjects who underwent 100-g oral glucose tolerance tests (OGTT) during pregnancy. HbA1c and other variables were analyzed to evaluate their diagnostic performance for GDM. To evaluate the clinical usefulness of HbA1c in predicting future type 2 DM development, we classified GDM subjects who had more than 3 months of follow-up data into two subgroups: those who developed postpartum type 2 DM (PDM) and those who did not.

RESULTS

HbA1c was significantly higher in the GDM group than in the normal control group. With the 100-g OGTT as reference, HbA1c showed 91.3% sensitivity and 62% specificity at a cut-off value of 5.05% (32 mmol/mol) for GDM diagnosis. At a cut-off value of 5.25% (34 mmol/mol), sensitivity was 73.6% and specificity was 77.2%. HbA1c levels during pregnancy were higher in those with PDM than in those without PDM (5.91 [41 mmol/mol] vs. 5.44% [36 mmol/mol], p<0.001). The prognostic value of HbA1c for PDM was evaluated by ROC curve analysis, with sensitivity of 78.6% and specificity of 72.5% at a cut-off value of 5.55% (37 mmol/mol).

CONCLUSIONS

HbA1c showed high sensitivity with relatively low specificity for diagnosis of GDM in pregnant women and was a potential predictor of PDM. HbA1c may be able to be used as a simple and less invasive alternative screening test for OGTT in GDM patients.

Usefulness of maternal serum C-reactive protein with vaginal Ureaplasma urealyticum as a marker for prediction of imminent preterm delivery and chorioamnionitis in patients with preterm labor or preterm premature rupture of membranes

AIM

To assess whether maternal serum C-reactive protein (CRP) and genital mycoplasmas measured can help predict imminent preterm delivery or chorioamnionitis in patients with preterm labor (PL) or preterm premature rupture of membranes (PPROM).

METHODS

The study group consisted of 165 women with PL or PPROM. Vaginal cultures for genital mycoplasmas and maternal blood for CRP were obtained when they were admitted for the management of PL or PPROM. An elevated level of serum CRP was defined as ≥0.8 mg/dL. Histologic evaluation of the placenta was performed after delivery.

RESULTS

The prevalence of positive vaginal fluid cultures for Ureaplasma urealyticum (UU) was 63.0%, and elevated maternal serum CRP was 32.7%. No outcome variables were associated with vaginal UU infection in patients with lower CRP levels. However, among women with elevated CRP, the mean gestational age at birth was significantly reduced, and low Apgar score, neonatal intensive care unit admission, histologic chorioamnionitis, and delivery within 7 days of admission were significantly more common in patients with vaginal UU.

CONCLUSIONS

Although vaginal UU in PL or PPROM cannot act as the sole predictor of imminent preterm delivery or chorioamnionitis, it can provide predictive information in patients with elevated maternal serum CRP levels.

Comparison of clinical and serological differences among juvenile-, adult-, and late-onset systemic lupus erythematosus in Korean patients

OBJECTIVES

We investigated whether systemic lupus erythematosus (SLE) patients could be distinguished based on the time of disease onset and, if so, whether the groups differed in their clinical and laboratory features in ethnically homogeneous Korean patients.

METHODS

We enrolled 201 SLE patients with available clinical data at the time of onset of SLE from the lupus cohort at Chonnam National University Hospital. Sociodemographic, clinical, and laboratory data, including autoantibodies, and concomitant diseases were found at the time of diagnosis of SLE by reviewing patient charts. We divided SLE patients according to age at SLE diagnosis into three groups: juvenile-onset SLE (JSLE, diagnosed at ≤ 18 years), adult-onset SLE (ASLE, diagnosed at 19-50 years), and late-onset SLE (LSLE, diagnosed at >50 years), and compared baseline demographic, clinical, and relevant laboratory findings.

RESULTS

Of the 201 patients, 27 (14.4%), 149 (74.1%), and 25 (12.4%) were JSLE, ASLE, and LSLE patients, respectively. Fever, oral ulcers, nephritis, anemia, and thrombocytopenia were more common in JSLE patients than ASLE or LSLE patients (p < 0.05, < 0.05, 0.001, < 0.05, and < 0.05, respectively). However, Sjögren's syndrome was more frequent in LSLE patients than JSLE or ASLE patients (p < 0.05). Disease activity was significantly higher in JSLE patients than in ASLE or LSLE patients (p < 0.001). Anti-dsDNA and anti-nucleosome antibodies were found more frequently in JSLE patients and less frequently in LSLE patients (p < 0.05 and 0.005, respectively) and decreased complement levels were more common in JSLE patients and less common in LSLE patients (p < 0.001, 0.001, and < 0.05, respectively).

CONCLUSIONS

Our results indicate that SLE patients present with different clinical and serological manifestations according to age at disease onset. JSLE patients have more severe disease activity and more frequent renal involvement and LSLE patients have milder disease activity, more commonly accompanied by Sjögren's syndrome, at disease onset.

Single-electron shuttle based on electron spin

A nanoelectromechanical device based on magnetic exchange forces and electron spin flips induced by a weak external magnetic field is suggested. It is shown that this device can operate as a new type of single-electron "shuttle" in the Coulomb blockade regime of electron transport.

Co-infection with vaginal Ureaplasma urealyticum and Mycoplasma hominis increases adverse pregnancy outcomes in patients with preterm labor or preterm premature rupture of membranes

OBJECTIVE

The purpose of this study was to determine the prevalence of Ureaplasma urealyticum (UU) and Mycoplasma hominis (MH) in patients with preterm labor or preterm premature rupture of membranes (PPROM) and to determine the effect of these organisms on pregnancy outcomes based on the density of colonization.

METHODS

The study group consisted of 184 women with preterm labor or PPROM. Vaginal cultures for UU and MH were performed for all patients at admission, and the placentas were histologically evaluated after delivery.

RESULTS

The prevalence of positive vaginal fluid cultures for genital mycoplasma was 62.5% (112/179). This group included 99 patients carrying only UU and 13 carrying both organisms. No patients were found to carry only MH. Compared to patients only positive for UU, patients with both organisms showed significantly decreased gestational age at birth and birth weight, and significant increases in the incidences of preterm birth, NICU admissions and histologic chorioamnionitis.

CONCLUSION

Vaginal MH tends to be detected with UU, and patients carrying both organisms simultaneously had more severe adverse pregnancy outcomes compared to patients in preterm labor or PPROM who were only positive for UU.

CCR5 gene polymorphism is a genetic risk factor for radiographic severity of rheumatoid arthritis

The chemokine receptor [C-C chemokine receptor 5 (CCR5)] is expressed on diverse immune effecter cells and has been implicated in the pathogenesis of rheumatoid arthritis (RA). This study sought to determine whether single-nucleotide polymorphisms (SNPs) in the CCR5 gene and their haplotypes were associated with susceptibility to and severity of RA. Three hundred fifty-seven patients with RA and 383 healthy unrelated controls were recruited. Using a pyrosequencing assay, we examined four polymorphisms -1118 CTAT(ins) (/del) (rs10577983), 303 A>G (rs1799987), 927 C>T (rs1800024), and 4838 G>T (rs1800874) of the CCR5 gene, which were distributed over the promoter region as well as the 5' and 3' untranslated regions. No significant difference in the genotype, allele, and haplotype frequencies of the four selected SNPs was observed between RA patients and controls. CCR5 polymorphisms of -1118 CTAT(del) (P = 0.012; corrected P = 0.048) and 303 A>G (P = 0.012; corrected P = 0.048) showed a significant association with radiographic severity in a recessive model, and, as a result of multivariate logistic regression analysis, were found to be an independent predictor of radiographic severity. When we separated the erosion score from the total Sharp score, the statistical significance of CCR5 polymorphisms showed an increase; -1118 CTAT(ins) (/del) (P = 0.007; corrected P = 0.028) and 303 A>G (P = 0.007; corrected P = 0.028). Neither SNPs nor haplotypes of the CCR5 gene showed a significant association with joint space narrowing score. These results indicate that genetic polymorphisms of CCR5 are an independent risk factor for radiographic severity denoted by modified Sharp score, particularly joint erosion in RA.

Determination of molecular weights of caprine milk proteins by matrix-assisted laser desorption/ionization mass spectrometry

Molecular weights (MW) of major proteins in milk of 3 Korean dairy goat breeds were determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, after treatment of milk samples with the reduction buffer used in capillary electrophoresis. The MW of caprine milk proteins were compared with those of Holstein milk counterparts using commercial bovine milk protein standards. The MW of α-lactalbumin, β-lactoglobulin, and α- and β-casein standards were 14,197±3.4, 18,326±26.3, 23,591±13.0, and 23,967±12.8 m/z, respectively, whereas those of Holstein milk treated with the reduction buffer were 14,199±8.3, 18,397±25.9, 23,614±64.8, and 23,984±75.6 m/z, respectively. The respective MW of α-lactalbumin in Saanen, Toggenberg, and Alpine milk were 14,194±27.2, 14,266±105.9, and 14,241±13.2 m/z, which were not different from those of the bovine milk. The respective MW of β- lactoglobulin in corresponding caprine milk were 18,840±31.5, 18,856±26.3, and 18,857±21.3 m/z, which were higher than those in the bovine milk. The MW of β-casein in corresponding caprine milk were 23,860±27.2, 23,886±12.3, and 23,901±8.4 m/z, which were lower than those in the bovine milk. The results indicated that matrix-assisted laser desorption/ionization time-of-flight mass spectrometry could be used for rapid determination of MW of Korean caprine milk proteins without protein separation steps.

Intercellular adhesion molecule-1 K469E polymorphism: Is it associated with preeclampsia in the Korean population?

OBJECTIVE

To examine whether the distribution of genotypic and allelic frequencies of ICAM-1 K469 of Korean women with preeclampsia are different from that of a control group.

STUDY DESIGN

In this case-control study the ICAM-1 K469E polymorphism was genotyped in 42 women with preeclampsia and 138 normotensive controls who had delivered at least two normal, term infants. A direct sequencing reaction method was used to detect a single nucleotide polymorphism.

RESULTS

The distribution of genotype frequencies and the frequency of the K469 allele of the preeclampsia group were not significantly different from those of the controls. A similar trend was observed between the severe preeclampsia patients and the controls.

CONCLUSION

The frequencies of the KK genotype and the K allele were higher in the preeclampsia group than those in the control group. However, there was no statistically significant difference.

Comparison of nuchal translucency measurements obtained using Volume NT(TM) and two- and three-dimensional ultrasound

OBJECTIVE

To evaluate the feasibility of Volume NT(TM) , a new technique that automatically archives mid-sagittal plane views and measures the maximum nuchal translucency (NT) thickness, by comparing its measurements with those made with conventional two- (2D) and three-dimensional (3D) techniques.

METHODS

This was a prospective study of 130 singleton pregnancies undergoing NT screening at 11 + 0 to 13 + 6 weeks of gestation. Fetuses with enlarged NT or multiple anomalies and those in the prone position were excluded. Success rate of NT measurement was assessed using Volume NT(TM) , 2D and 3D techniques. In cases in which all three techniques were successful, intra- and interobserver bias and levels of agreement for NT measurements within and between techniques were evaluated using Bland-Altman plots.

RESULTS

Of 130 cases enrolled into the study, 16 were excluded from analysis due to enlarged NT (n = 3), prone position (n = 2) or missing data (n = 11). Among the 114 cases analyzed, NT measurement was successful by the conventional 2D method in 95.6% (109/114) of cases and by 3D and Volume NT(TM) measurements in 103 and 93 cases, respectively. Success rate was not significantly different between methods. In 89 cases, NT values were available using all three methods. Among them, mean ± SD 2D-NT was 1.3 ± 0.4 mm, 3D-NT was 1.2 ± 0.4 mm and Volume NT(TM) was 1.3 ± 0.4 mm. The mean differences of the intra- and interobserver variability of each method were not significantly different from zero for each method.

CONCLUSIONS

Volume NT(TM) , a novel technique for automated NT measurement, is apparently reproducible and comparable with conventional 2D and 3D ultrasound techniques for NT measurement.

Clinical significance of serum sRAGE and esRAGE in women with normal pregnancy and preeclampsia

BACKGROUND

We determined serum endogenous secretory receptor of advanced glycation end products (esRAGE) and soluble RAGE (sRAGE) concentrations and the esRAGE/sRAGE ratio in normal pregnancy and preeclampsia because esRAGE and sRAGE have been negatively linked to components of metabolic syndromes and pathologic pregnancy including preeclampsia.

METHOD

Eighty-seven normal pregnant women and 28 with preeclampsia were recruited. Serum sRAGE and esRAGE levels were measured by enzyme-linked immunosorbent assay.

RESULTS

There were significant differences in esRAGE concentration and esRAGE/sRAGE ratio between 1(st) and 3(rd) trimester in normal pregnancy (P=0.007 and P=0.003). Serum esRAGE concentrations and esRAGE/sRAGE ratio in patients with preeclampsia significantly increased compared to controls (P=0.005 and P<0.001).

CONCLUSIONS

Maternal serum esRAGE concentration and esRAGE/sRAGE ratio (1) gradually decrease with gestational age in normal pregnancy; and (2) are higher in patients with preeclampsia than healthy pregnant controls, significantly. Serum esRAGE and esRAGE/sRAGE ratio might be associated with preeclampsia.

Serum markers for prediction of spontaneous preterm delivery in preterm labour

BACKGROUND

Simple, more sensitive markers to predict spontaneous preterm delivery in preterm labour are needed. The aim of this study is to compare the clinical effectiveness of various serum inflammatory markers and cervix length for prediction of spontaneous preterm delivery.

MATERIALS AND METHODS

We retrospectively reviewed medical records of 175 patients hospitalized for preterm labour (102 with preterm delivery and 73 with term delivery). For all study subjects, haematological markers and cervix length were recorded on admission. Because neutrophil to lymphocyte ratio (NLR) showed the potential as a diagnostic marker, we designed a combined marker by dividing cervix length by NLR. The diagnostic and prognostic accuracy of the combined marker was analysed using multivariate analyses.

RESULTS

The levels of combined marker (P < 0·001), neutrophil (P < 0·001), lymphocyte (P = 0·02), NLR (P < 0·001), C-reactive protein (P = 0·016) and the cervix length (P < 0·001) in preterm delivery group were significantly different from those of term delivery group. Compared to cervix length or systemic inflammatory markers alone, combined marker showed higher sensitivity (64·2%) and specificity (88·3%) for prediction of preterm delivery. On Cox multivariate analysis, combined marker positive (< 0·29) and short cervix length (< 1·7 cm) were independent poor prognostic factors and combined marker positive was the most powerful prognostic marker for spontaneous preterm delivery (hazard ratio = 5·60, P < 0·001).

CONCLUSIONS

Combined marker could be used as a simple and sensitive parameter for identifying women at risk of spontaneous preterm delivery.

Pregnancy outcome after cervical conization: risk factors for preterm delivery and the efficacy of prophylactic cerclage

OBJECTIVE

This study examined the risk factors for preterm birth and the efficacy of prophylactic cerclage in patients who had undergone cervical conization due to cervical intraepithelial neoplasia before pregnancy.

METHODS

We reviewed the medical records of all patients who gave live singleton births between May 1996 and April 2009, after having cervical conization. Delivery before 37 gestational weeks was considered as preterm birth. The pregnancy outcomes were analyzed with independent sample t-test, chi-square test, and multiple logistic regression using the SPSS ver. 12.0.

RESULTS

Sixty five cases were found. The mean gestational age at delivery was 37 weeks (SD, 3.5). Eighteen patients (27.7%) had preterm delivery. The type of conization, the volume of the specimen, and second trimester cervical length were related to preterm birth (p≤0.001, p=0.019, p≤0.001, respectively). In multivariate analysis, only mid-trimester cervical length was statistically significant for preterm birth (p=0.012; odds ratio, 0.194; confidence interval, 0.055 to 0.693). Six out of 65 patients had undergone prophylactic cerclage, and three (50%) of them had preterm births, while 15 (25%) patients without cerclage had preterm births.

CONCLUSION

The type of conization, the volume of specimen, and second trimester cervical length may be the risk factors for preterm birth in patients who have a prior history of cervical conization. Prophylactic cerclage may not be helpful in preventing preterm birth, therefore more careful consideration should be paid in deciding cerclage after conization during prenatal counseling.

A unit-coordinator system: an effective method of reducing inappropriate hospital stays

BACKGROUND

Many hospitals would benefit from a reduction in the length of inpatient hospital stays; in this regard, nursing approaches require complementation to ensure optimized nursing care. Such action is particularly important in general hospitals in Korea, where the ratio of patients to nurses is more than 10:1.

OBJECTIVES

This study aimed to determine the effectiveness of a unit-coordinator system in complementing primary nursing in general hospitals as a means of reducing inappropriate hospital stays.

METHODS

The unit-coordinator system was implemented in seven wards in a hospital in Seoul for 8 weeks. The existing primary nursing system was maintained, and newly placed unit-coordinators organized the activities within each ward. The numbers of early admissions and early discharges were determined by assessing the electronic administrative records of the hospital. Further, the number of patients who had undergone check-ups and chemotherapy on the day of admission was confirmed from the daily reports of each ward. The effect of the unit-coordinator system on nurse satisfaction was assessed through direct interviews.

FINDINGS

Early-discharge and early-admission numbers increased significantly after implementation of the unit-coordinator system. Early admission allowed check-ups and treatments to be performed on the day of admission. Thus, this system reduced the length of hospital stay by 1 day, and the total reduction of inappropriate hospital stays over the 8-week study period was 66 days. Further, the unit-coordinator system also increased nurse satisfaction.

CONCLUSION

The unit-coordinator system is an effective method of complementing primary nursing and reducing inappropriate hospital stays.

Mel-18, a mammalian Polycomb gene, regulates angiogenic gene expression of endothelial cells

Mel-18 is a mammalian homolog of Polycomb group (PcG) genes. Microarray analysis revealed that Mel-18 expression was induced during endothelial progenitor cell (EPC) differentiation and correlates with the expression of EC-specific protein markers. Overexpression of Mel-18 promoted EPC differentiation and angiogenic activity of ECs. Accordingly, silencing Mel-18 inhibited EC migration and tube formation in vitro. Gene expression profiling showed that Mel-18 regulates angiogenic genes including kinase insert domain receptor (KDR), claudin 5, and angiopoietin-like 2. Our findings demonstrate, for the first time, that Mel-18 plays a significant role in the angiogenic function of ECs by regulating endothelial gene expression.

De novo appearance of primitive neuroectodermal tumor in a patient with systemic lupus erythematosus and moyamoya disease

Primitive neuroectodermal tumor is a rare brain tumor composed of undifferentiated or poorly differentiated neuroepithelial cells with a high malignant potential that usually occurs in children, and which is only occasionally encountered in adults. A 19-year-old female with systemic lupus erythematosus presented with right hemiparesis and a headache of 10 days duration. Brain magnetic resonance imaging showed a large solid mass with necrotic portions in the left frontoparietal lobe. Primitive neuroectodermal tumor was confirmed by a neuronavigator-guided brain biopsy. This is the first case report of primitive neuroectodermal tumor associated with systemic lupus erythematosus and moyamoya disease. This case demonstrates that brain tumors, such as primitive neuroectodermal tumor, should be included in the differential diagnosis of neurological manifestations in children and adolescent patients with systemic lupus erythematosus.

Generation of expression clone set for functional proteomics of human gastric and liver cancers

Two thousand sixty-eight multi-purpose expression clones for the 326 candidate genes related to gastric or liver cancers were constructed using the Gateway system. These clones can be expressed as His, Glutathione-S-transferase (GST) or Enhanced version of the green fluorescent protein (EGFP) fusion proteins in E. coli, insect cells or mammalian cells. For the 246 E. coli expression clones, the GST fusion proteins had greater expression efficiency and solubility than the His fusion proteins. Approximately 20% of the expressed proteins had unexpected molecular weights. A detailed sequence analysis of these clones revealed frameshift mutations resulting from insertion, deletion or substitution of nucleotides. The results indicate that these changes in the candidate genes may affect the occurrence of gastric or liver cancers. In addition, when 105 proteins, which were expressed in E. coli at very low or undetectable levels, were expressed in insect cells, 76% of the proteins were expressed very well and most were soluble. We also found that most of the 30 proteins prepared using EGFP mammalian expression clones were localized to cellular compartments expected by Gene ontology (GO) and this localization was unaffected if the EGFP-fusion was at the N-terminal or C-terminal region of the protein. Antibody production and subcellular localization analysis of the candidate genes as well as a screen of genes involved in carcinogenesis pathways are currently in progress using these expression clones. These studies provide a valuable resource for developing a better understanding of the molecular mechanism of carcinogenesis in both gastric and liver cancer and would be very helpful in diagnosis and therapeutic predictions.

Lupus-associated pancreatitis complicated by pancreatic pseudocyst and central nervous system vasculitis

Pancreatitis is an uncommon manifestation of systemic lupus erythematosus (SLE), but this can occasionally cause major complications. We report in this article, a case of 33-year-old female patient who developed lupus-associated pancreatitis that was subsequently complicated by pancreatic pseudocyst and central nervous system (CNS) vasculitis. Abdominal computed tomography (CT) showed an oedematous swelling of the pancreas and a pseudocyst measuring 4 x 3 cm2. Brain magnetic resonance imaging (MRI) showed multiple high-signal intensity lesions in both cerebral hemispheres. The pseudocyst did not completely resolve with high-dose steroid therapy, and it was later complicated by infection and rupture. After a surgical drainage for the complicated pseudocyst, her clinical symptoms and signs were markedly improved. This case shows the importance of performing early drainage rather than conservative treatment for a pancreatic pseudocyst in a patient with lupus-associated pancreatitis.

Uterine artery Doppler velocimetry and maternal weight gain by the mid-second trimester for prediction of fetal growth restriction

OBJECTIVE

To investigate whether assessment of maternal weight gain up to mid-second trimester improves the predictive value of uterine artery Doppler velocimetry (UAD) for the prediction of fetal growth restriction (FGR).

SETTING

Department of Obstetrics and Gynecology, Yonsei University College of Medicine.

DESIGN

Prospective Doppler measurements coupled to retrospective chart review.

POPULATION

A total of 10,970 women delivering at the institution.

OUTCOME MEASURES

Maternal weight gain up to mid-second trimester and Doppler ultrasonography on bilateral uterine arteries between 20 and 24 weeks' gestation. Low weight gain was defined as <0.2 kg/week and FGR as birthweight of <10th percentile.

RESULTS

ith that combined with the measurement of maternal weight gain for the prediction of the FGR. The odd ratios for FGR were 2.56 (95% CI 1.59-4.12) in the group with normal UAD and abnormal weight gain (normal-abnormal group), 1.91 (95% CI 0.98-3.7) in the abnormal-normal group and 40.3 (95% CI 16.9-96.4) in the abnormal-abnormal group. UAD independent of weight gain had a sensitivity of 31.5%, a specificity of 88%, a positive predictive value (PPV) of 24.5% and a negative predictive value (NPV) of 91.2%. When mid-trimester maternal weight gain was accounted for, the sensitivity of UAD was 64.9%, specificity 64.1%, PPV 73.3% and NPV 93.6%.

CONCLUSION

The diagnostic performance of UAD for FGR improved significantly when the degree of maternal weight gain until the mid-second trimester was taken into account. Closer antenatal surveillance might be required in women with abnormal uterine Doppler velocimetry if their mid-second trimester weight gain is poor.

Increased senescence and reduced functional ability of fetal endothelial progenitor cells in pregnancies complicated by preeclampsia without intrauterine growth restriction

OBJECTIVE

The aim of this study was to investigate the number and functional ability of fetal endothelial progenitor cells in pregnancies complicated by preeclampsia without intrauterine growth restriction.

STUDY DESIGN

Fetal endothelial progenitor cells were isolated, and counted from 17 women with preeclampsia without intrauterine growth restricion and 30 normal women. Colony-forming assay and differentiation time assay were performed to detect functional activity of the cells. To assess cellular senescence, senescence-associated beta-galactosidase staining was performed for endothelial progenitor cells.

RESULTS

Compared with normal pregnancy, the number of endothelial progenitor cells was significantly lower, differentiation time from endothelial progenitor cell into outgrowing cell was longer, and the number of colonies after differentiation was smaller in preeclampsia (P< .001), respectively. The intensity of senescence-associated beta-galactosidase staining was higher in preeclamptic pregnancy (P < .001).

CONCLUSION

The number and functional ability of fetal endothelial progenitor cells from preeclampsia without intrauterine growth restriction are significantly decreased and they are more senescent compared with those of normal pregnancy.

A carbon nanotube gated carbon nanotube transistor with 5 ps gate delay

Semiconducting carbon nanotubes (CNTs) are attractive as channel material for field-effect transistors due to their high carrier mobility. In this paper we show that a local CNT gate can provide a significant improvement in the subthreshold slope of a CNT transistor compared to back gate switching and provide gate delays as low as 5 ps. The CNT gated CNT transistor devices are fabricated using a two-step chemical vapour deposition technique. The measured transfer characteristics are in very good agreement with theoretical modelling results that provide confirmation of the operating principle of the transistors. Gate delays below 2 ps should be readily achievable by reducing the thickness of the gate dielectric.

Nestin expression during differentiation of fetal endothelial progenitor cells and hypoxic culture of human umbilical vein endothelial cells

OBJECTIVE

The aim of this study was to assess whether nestin is expressed during differentiation of endothelial progenitor cells (EPCs) obtained from human umbilical cord blood (HUCB), and nestin expression is changed in hypoxia-conditioned culture of human umbilical vein endothelial cells (HUVECs).

METHODS

Among deliveries at our institute, 20 normal pregnant women who delivered by cesarean section at 37-40 weeks' gestation were selected. HUCB mononuclear cells (MNCs) from HUCB were isolated and cultivated. After characterization of CXCR4/KDR/CD34 positive cells (EPCs) by flow cytometry and fluorescent chemical staining, EPC culture was continued through day 10 for differentiation to outgrowth endothelial cell (OEC). For identification of EPC and OEC, RT-PCR was performed for each specific cell markers, such as AC133, CD45, CXCR4, CDH5, vWF, eNOs, CD34, and Flt 1. HUVECs were isolated from human umbilical cord veins by collagenase treatment. Culture of HUVEC in hypoxic and normoxic conditions was performed for 24 h. Nestin expression in EPCs, OECs and HUVECs was detected by RT-PCR and Western blotting.

RESULTS

Western blot analysis and RT-PCR revealed that nestin was not expressed in EPC, but well expressed in OECs and HUVECs. During 24 h of HUVEC culture, time course gene expression of VEGF was significantly increased, but nestin was not changed.

CONCLUSIONS

Our results showed that nestin could be used as a new differentiation marker of EPCs, and hypoxic stimuli did not directly affect nestin gene expression.

Moyamoya syndrome associated with systemic lupus erythematosus

Abstract

Moyamoya disease is a rare, progressive cerebrovascular disorder that is characterized by a stenosis or occlusion of the bilateral internal carotid arteries and the development of collateral vessels. Transient ischemic attacks or seizures are the usual presentation of moyamoya disease in children, whereas cerebral hemorrhage is the most common symptom in adults. We report an 18-year-old female patient with active lupus nephritis who presented with the sudden onset of left hemiparesis. Brain magnetic resonance imaging showed acute infarctions in the right basal ganglia and subcortical white matter of the right frontal lobe. Cerebral angiography showed the stenosis of the bilateral internal carotid arteries with rich basal collateral vessels (moyamoya vessels). There was no evidence of atherosclerosis or antiphospholipid syndrome. Glucocorticoid therapy was used to control the systemic lupus erythematosus. Prophylactic bypass surgery was performed to prevent recurrent ischemic attacks. This case report shows that an underlying cerebrovascular lesion of moyamoya vessels in a patient with systemic lupus erythematosus is susceptible to cerebrovascular accidents.

Differential expression of nestin in normal and pre-eclamptic human placentas

BACKGROUND

Nestin is a type VI intermediate filament protein originally described in neural stem cells. Recent reports have documented nestin expression in endothelium of newly formed blood vessels and suggested its role as a marker of capacity for neovascularization and angiogenesis in endothelial cells. The aim of this study was to investigate the differential expression of nestin in normal and pre-eclamptic human placentas.

METHODS

Placental tissues from 12 women with severe pre-eclampsia and 15 gestational age-matched normotensive women were collected at the time of their cesarean section. Western blot analysis for each placental tissue was performed for nestin quantification. Immunohistochemical staining was employed to localize nestin-positive cells and to investigate differential staining intensity in each placental cell.

RESULTS

Nestin expression was detected in all of the normal and pre-eclamptic placental tissues by Western blotting. Compared with the normal placentas, tissues from severe pre-eclamptic placentas showed higher expression of nestin (p<0.001). Nestin immunoreactivity was localized only to endothelial cells of chorionic villi. However, mesenchymal connective tissue cells, cytotrophoblasts, syncytiotrophoblasts, and decidual cells did not reveal any specific signal for nestin.

CONCLUSIONS

We suggest that the capacity for neovascularization and angiogenesis in endothelial cell is increased in pre-eclamptic placenta compared to that from normal pregnancy. Such changes may be a compensatory mechanism for the reduced maternofetal exchanges and long-lasting fetal hypoxia in pre-eclamptic pregnancy. Furthermore, these changes in endothelial cells of chorionic villi in pre-eclamptic pregnancy may give an explanation for fetal response to pre-eclamptic conditions.

Kawasaki disease in Korea, 2003-2005

PURPOSE

The aim of this study was to investigate the incidence rate and epidemiologic patterns of Kawasaki disease in Korea for the 3-year-period, 2003-2005.

METHODS

The questionnaire for an epidemiologic survey on Kawasaki disease was distributed to all 102 Korean hospitals that conduct pediatric residency programs, and obtained data were analyzed upon receipt.

RESULTS

The 9662 patients of Kawasaki disease from 85 hospitals that responded (response rate, 83.3%) consisted of 5877 males and 3785 females (male:female ratio, 1.55:1). The incidence rate per 100,000 children <5-year-old was 104.2 in 2003, 106.4 in 2004, and 104.6 in 2005 (average rate, 105.0). Their mean age of onset was 33.3 months, and the proportions of sibling cases and recurrent cases were 0.29% and 2.0%, respectively. Coronary arterial abnormalities were detected at follow-up by echocardiogram in 18.8% of all such cases including dilatations of 18.0% and aneurysms of 2.5%.

CONCLUSION

The average annual rate of incidence, 105.0/100,000 in children <5-year-old is the second highest reported rate in the world.

The usefulness of fetal MRI for prenatal diagnosis

PURPOSE

Fast MRI has provided detailed and reproducible fetal anatomy. This study was performed to evaluate the usefulness of fetal MRI for prenatal diagnosis.

MATERIALS AND METHODS

Fifty-six fetuses with congenital abnormalities on ultrasonography were evaluated by fetal MRI from 2001 to 2004 in Severance Hospital. Final diagnosis was made by postnatal pathology, postnatal MRI, and other modalities (such as ultrasound, retrograde pyelogram). A 1.5-Tesla superconductive MR imaging unit was used to obtain half-Fourier acquisition single-shot turbo spin images.

RESULTS

Of the 56 fetuses, intracranial abnormalities were found in 26 fetuses, intraabdominal abnormalities in 17 fetuses, intrathoracic in 6 fetuses, head and neck in 5 fetuses, and other sites in 2 fetuses. There were six cases in which the diagnoses of fetal MRI and ultrasonography differed. In such cases, fetal MRI provided more exact diagnosis than ultrasonography (5 vs. 0). Three fetuses with intracranial abnormalities on ultrasonography were diagnosed as normal by fetal MRI and in postnatal diagnosis.

CONCLUSION

Although ultrasonography is known as a screening modality of choice in the evaluation of fetus because of the cost-effectiveness and safety, the sonographic findings are occasionally inconclusive or insufficient for choosing the proper management. Thus, in this study, we suggest that fetal MRI is more useful than ultrasonography for the evaluation of intracranial abnormalities in some instances. For prenatal counseling and postnatal treatment planning, fetal MRI can be informative when prenatal ultrasonography is inadequate and doubtful.

Expression profile of tight junction protein claudin 3 and claudin 4 in ovarian serous adenocarcinoma with prognostic correlation

Tight junction proteins claudin 3 (CLDN3) and claudin 4 (CLDN4) are frequently altered in several human cancers, including ovarian carcinomas. Here, we examined the gene expression of CLDN3 and CLDN4 in various tumors, including 19 normal ovaries and 47 ovarian carcinomas by analyzing Affymetrix HG-U133 array data. Furthermore, a total of 114 ovarian serous tumors, including 10 adenomas, 20 borderline tumors and 84 carcinomas, were analyzed immunohistochemically to confirm the expression of two proteins and we assessed the association of their expression with the clinicopathological characteristics and survival of the patients. The microarray experiment revealed CLDN3 and CLDN4 transcripts were significantly up-regulated by 5-fold or more in most subtypes of ovarian epithelial carcinomas while the immunohistochemical analyses indicated that each protein was expressed in 68 (81.0%) and 72 (85.7%) of 84 serous adenocarcinomas, respectively. Borderline serous tumors and adenomas showed significantly lower expression of these proteins than the adenocarcinomas. Kaplan-Meier survival analysis showed that serous adenocarcinoma patients with high CLDN3 expression had substantially shorter survival (P=0.027). Multivariate analysis demonstrated that CLDN3 overexpression is an independent negative prognostic factor. Our findings suggest that CLDN3 overexpression can be used as a prognostic indicator in ovarian serous carcinomas. Moreover, CLDN3 may be a promising target for antibody-based therapy of ovarian carcinomas.

Maternal serum highly sensitive C-reactive protein in normal pregnancy and pre-eclampsia

OBJECTIVE

To establish reference values for highly sensitive C-reactive protein (hsCRP) in normal pregnancy and determine whether disease severity could be predicted by serum hsCRP concentration in women with severe pre-eclampsia (PE).

METHODS

Blood samples were collected from 25 pregnant women with severe PE and 202 healthy pregnant women who were divided into 4 groups by pregnancy duration. Levels of hsCRP were determined by the immunonephelometric method. Mean arterial pressure, time between delivery and diuresis, and mean ratio of systolic to diastolic blood flow velocity in uterine arteries were used as indicators of the severity of PE.

RESULTS

The median values of hsCRP in each group were 0.76 mg/L (0.16-13.61 mg/L), 1.53 mg/L (0.39-20.31 mg/L), 2.08 mg/L (0.50-9.45 mg/L), and 2.28 mg/L (0.44-8.11 mg/L) and showed a trend toward increase. Serum levels of hsCRP were positively correlated with each severity indicator of PE.

CONCLUSIONS

This study showed that hsCRP levels were positively correlated to pregnancy duration in healthy women and could be used as a severity marker in women with severe PE.

Enzymatic interesterification of tripalmitin with vegetable oil blends for formulation of caprine milk infant formula analogs

The structure of triacylglycerols in vegetable oil blends was enzymatically modified, and the blends were incorporated into skim caprine milk to produce goat milk-based infant formula analogs, homologous to human milk. A modified lipid containing palmitic, oleic, and linoleic acids, resembling the composition of human milk fat, was synthesized by enzymatic interesterification reactions between tripalmitin and a vegetable oil blend containing a 2.5:1.1:0.8 ratio of coconut, safflower, and soybean oils. A commercial sn-1,3-specific lipase obtained from Rhyzomucor miehei, Lipozyme RM IM, was used as the biocatalyst. The effects of substrate molar ratio and reaction time on the incorporation of palmitic, oleic, and linoleic acids at the sn-2 position of the triacylglycerols were investigated. The fatty acid composition and sn-2 position of the experimental formulas were analyzed using gas chromatography. Results showed that the highest incorporation of palmitic acid was obtained at 12 h of incubation at 55 degrees C with a substrate molar ratio of 1:0.4 of tripalmitin to vegetable oil blend. However, the modified milk interesterified for 12 h at a 1:1 molar ratio had a greater resemblance to human milk compared with the other formulas. The level of oleic acid incorporation at the sn-2 position increased with the molar ratio of tripalmitin to vegetable oil blend. It was concluded that, unlike the original goat milk and other formulas, the formulated caprine milk with a molar ratio of 1:1 and a 12-h incubation was similar to the fatty acid composition of human milk.

Enzymatic Production of Infant Milk Fat Analogs Containing Palmitic Acid: Optimization of Reactions by Response Surface Methodology

Infant milk fat analogs resembling human milk fat were synthesized by an enzymatic interesterification between tripalmitin, coconut oil, safflower oil, and soybean oil in hexane. A commercially immobilized 1,3-specific lipase, Lipozyme RM IM, obtained from Rhizomucor miehei was used as a biocatalyst. The effects of substrate molar ratio, reaction time, and incubation temperature on the incorporation of palmitic acid at the sn-2 position of the triacylglycerols were investigated. A central composite design with 5 levels and 3 factors consisting of substrate ratio, reaction temperature, and incubation time was used to model and optimize the reaction conditions using response surface methodology. A quadratic model using multiple regressions was then obtained for the incorporation of palmitic acid at the sn-2 positions of glycerols as the response. The coefficient of determination (R2) value for the model was 0.845. The incorporation of palmitic acid appeared to increase with the decrease in substrate molar ratio and increase in reaction temperature, and optimum incubation time occurred at 18 h. The optimal conditions generated from the model for the targeted 40% palmitic acid incorporation at the sn-2 position were 3 mol/mol, 14.4 h, and 55 degrees C; and 2.8 mol/mol, 19.6 h, and 55 degrees C for substrate ratio (moles of total fatty acid/moles of tripalmitin), time, and temperature, respectively. Infant milk fat containing fatty acid composition and sn-2 fatty acid profile similar to human milk fat was successfully produced. The fat analogs produced under optimal conditions had total and sn-2 positional palmitic acid levels comparable to that of human milk fat.