Effect of Microwave Treatment on Adzuki Beans (Vigna angularis L.) under Dry State—Analyzing Microstructure, Water Absorption, and Antioxidant Properties

In this study, a microwave was used on adzuki beans (Arari and Geomguseul) without water, in order to investigate their changes in microstructure, water absorption, and antioxidative properties. As the microwave treatment time increased (2450 MHz, 0 to 60 s), the lightness, redness, and yellowness were reduced, and moisture content significantly decreased in both varieties. The microstructure space between the seed coat, cotyledon, and pores within the cotyledon were observed, due to the loss of moisture. Regardless of microwave treatment, the water absorption behavior of the adzuki beans was sigmoidal. However, the water absorption kinetics of Arari increased after microwave treatment, whereas with microwave-treated Geomguseul, the water absorption rate decreased, compared to the control, except for the sample treated for 30 s. During soaking, the water absorption and softening rates in the microwave-treated adzuki bean were twice as fast as the untreated beans. Antioxidant activity, total phenolic compounds, and total flavonoid compounds were greatly improved by microwave treatment. These results indicate that microwave treatment affects the color, hydration, and bioactive compounds, and it can be used as a pretreatment method before processing adzuki beans.

Infusion of fluorescein into corn and waxy rice starches and its controlled release

The effects of concentration, temperature, and time on infusion of fluorescein into corn and waxy rice starches and their controlled release pattern were investigated. At low fluorescein concentration (1 μM), temperature significantly affected infusion efficiency. At high fluorescein concentration (50-150 μM), temperature showed little effect; fluorescein concentration significantly affected infusion efficiency. Corn starch showed relatively higher infusion efficiency than waxy rice starch at high concentration. During controlled release, 50% and 81% of infused fluorescein were released from corn and waxy rice starches, respectively, after bacterial α-amylase treatment. However, 61% and 68% of infused fluorescein were released from corn and waxy rice starches, respectively, after pancreatic α-amylase treatment. The dextrose equivalent (DE) value revealed similar patterns, suggesting that degradation of starch by different α-amylases is a major factor affecting release of fluorescein from starch granules. Moreover, granule size of starch greatly affected enzymatic hydrolysis and controlled release in this system.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01059-2.

Infusion efficiency of fluorescein derivatives of different molecular sizes into various starches under atmospheric and high hydrostatic pressures

Fluorescein isothiocyanate-dextrans (FDs) of different molecular weights were infused into corn, waxy rice, tapioca, and potato starches under atmospheric and high hydrostatic pressures (HHP). FD4, FD10, FD20, and FD40 (Mw 4000, 10,000, 20,000, and 40,000, respectively) were used as infusion materials. Confocal laser scanning microscopy confirmed that all FDs except FD40 infused into corn, waxy rice, and tapioca starches. However, no FDs infused into potato starch. Corn starch had the highest amounts of infused FDs. As molar mass increased, the amount of infused FD decreased in all starches. The infused amounts of FDs in corn starch were similar at 200-300 MPa and atmospheric pressure. Infusion of FDs at 400 MPa was reduced due to partial gelatinization. These results confirm that infusion efficiency is inversely proportional to the molecular weight of the infused material and large materials (Mw > 40,000) cannot be infused into starch granules under atmospheric pressure or HHP.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10068-021-00972-2.

Homological percolation transitions in growing simplicial complexes

Simplicial complex (SC) representation is an elegant mathematical framework for representing the effect of complexes or groups with higher-order interactions in a variety of complex systems ranging from brain networks to social relationships. Here, we explore the homological percolation transitions (HPTs) of growing SCs using empirical datasets and model studies. The HPTs are determined by the first and second Betti numbers, which indicate the appearance of one- and two-dimensional macroscopic-scale homological cycles and cavities, respectively. A minimal SC model with two essential factors, namely, growth and preferential attachment, is proposed to model social coauthorship relationships. This model successfully reproduces the HPTs and determines the transition types as an infinite-order Berezinskii-Kosterlitz-Thouless type but with different critical exponents. In contrast to the Kahle localization observed in static random SCs, the first Betti number continues to increase even after the second Betti number appears. This delocalization is found to stem from the two aforementioned factors and arises when the merging rate of two-dimensional simplexes is less than the birth rate of isolated simplexes. Our results can provide a topological insight into the maturing steps of complex networks such as social and biological networks.

Effect of hydrothermal treatment on physicochemical properties of amorphous granular potato starch (AGPS)

Using restructuring technology, A- or B-type crystalline granular potato starch was produced from amorphous granular potato starch (AGPS). AGPS was prepared using ethanol-heat processing, and hydrothermal treatments were performed with different moisture contents (18, 29, 200% d.b.) and temperatures (4, 25, 40, 60, 80 °C) for 3 weeks. AGPS showed no endothermic peak in a DSC thermogram, while hydrothermally treated AGPS (HAGPS) revealed endothermic peaks. In X-ray diffraction, AGPS displayed an amorphous pattern, and HAGPS displayed A- or B-type crystalline patterns depending on treatment temperature and moisture content. Neither AGPS nor HAGPS had typical RVA pasting curves, and their viscosities gradually increased. Raman spectroscopy and FT-IR confirmed that ordered structure and crystalline regions increased in HAGPS. Resistant starch (RS) and slowly digestible starch (SDS) contents of HAGPS increased but rapidly digestible starch (RDS) content decreased compared to AGPS. These results elucidated that hydrothermal treatment could change the physicochemical properties of AGPS and produce an identical material, such as granular potato starch with A-type and B-type crystalline granular potato starch.

Starch nanoparticles prepared by enzymatic hydrolysis and self-assembly of short-chain glucans

Enzymatic hydrolysis and self-assembly are considered promising methods for preparation of starch nanoparticles (SNPs) because they are environmentally friendly, and time- and cost-effective. These methods are based on the self-assembly of short-chain glucans released from the α-1,6 bonds in amylopectin. Since their discovery, many studies have described the structural and physicochemical properties of self-assembled SNPs. Self-assembled SNPs can be prepared by two methods: using only the soluble portion containing the short-chain glucans, or using the whole hydrolyzate including both insoluble and soluble fractions. Although the structural and physical properties of self-assembled SNPs can be attributed to the composition of the hydrolyzates that participate in self-assembly, this aspect has not yet been discussed. This review focuses on SNPs self-assembled with only soluble short-chain glucans and addresses their characteristics, including formation mechanisms as well as structural and physicochemical properties, compared with SNPs prepared with total hydrolyzates.

Physicochemical and retrogradation properties of modified chestnut starches

Physicochemical properties of acetylated (AC), cross-linked (CL), and hydroxypropylated (HP) chestnut starches were investigated. Modified chestnut starch showed low RS and amylose contents. AC revealed the highest solubility and HP showed the highest swelling power at 60 °C. CL showed the lowest solubility and swelling power at both 60 and 90 °C. AC and HP showed a lower pasting temperature and higher peak viscosity than native chestnut starch (NC). Modified chestnut starch formed gels at higher solid content than NC. CL had the lowest freeze-thaw stability, and AC and HP showed the strongest tolerance to freeze-thaw cycles. Amylopectin melting enthalpy of NC dramatically increased over the first 2 days and continued increasing gradually until day 24. On the other hand, all the modified chestnut starches showed a slight increase in amylopectin melting enthalpy, indicating retarded retrogradation. CL showed the lowest degree of retrogradation, followed by HP, AC, and NC.

Characterization of amorphous granular starches prepared by high hydrostatic pressure (HHP)

Amorphous granular starches (AGS) and non-granular amorphous starches (non-AGS) of corn, tapioca and rice were prepared using high hydrostatic pressure (HHP) treatment with ethanol and water washing, respectively and their physicochemical properties were investigated. Water holding capacity and apparent viscosity of AGS and non-AGS were higher than those of native one in all starches. In RVA pasting properties, AGS and non-AGS showed higher pasting temperature and lower peak viscosity than those of native one. Furthermore, non-AGS showed distinctively lower peak viscosity compared to that of AGS possibly due to its non-granular structure. Apparent viscosity of non-AGS revealed relatively lower than commercial pre-gelatinized starch because of heat and pressure-induced gelatinization. Maintaining granular structure in HHP treated pre-gelatinized starch provide a distinctive physicochemical characteristics compared to native starch and preparation of gelatinized starch with different gelatinization and washing methods could cause big differences in their physicochemical properties.

Retrogradation kinetics of chestnut starches cultivated in three regions of Korea

Retrogradation kinetics of chestnut starches from three different regions of Korea were investigated during storage at 4 °C. The retrogradation properties were determined using four DSC characteristics: glass transition temperature ( T g ' ), ice melting enthalpy (ΔH_i), amylopectin melting enthalpy (∆H_r) and degree of retrogradation (DR). The Gongju (GJ) starch showed the highest gelatinization enthalpy (∆H_g) value, followed by Gwangyang (GY) and Hadong (HD). T g ' of all samples gradually increased with increasing storage time, while ∆H_i decreased as the storage time increased. ∆H_r of all samples significantly increased after 2 days of storage. DR, calculated based on ∆H_g and ∆H_r, showed a similar tendency with ∆H_r. The retrogradation rates of three chestnut starches were analyzed using the Avrami equation, and the time constants (1/k) were obtained. GY, GJ and HD showed the fastest retrogradation rate in T g ' , ∆H_i, and ∆H_r, respectively suggesting that each sample experienced different retrogradation kinetics in different region.

Repetitive Transcranial Magnetic Stimulation of the Primary Somatosensory Cortex Modulates Perception of the Tendon Vibration Illusion

The effect of repetitive transcranial magnetic stimulation on kinesthetic perception, when applied to the somatosensory cortex, was examined. Further, the facilitatory and inhibitory effects of repetitive transcranial magnetic stimulation using different stimulation frequencies were tested. Six female (M age = 32.0 years, SD = 6.7) and nine male (M age = 32.9 years, SD = 6.6) participants were asked to perceive the tendon vibration illusion of the left wrist joint and to replicate the illusion with their right hand. When comparing changes in the corresponding movement amplitude and velocity after three different repetitive transcranial magnetic stimulation protocols (sham, 1 Hz inhibitory, and 5 Hz facilitatory repetitive transcranial magnetic stimulation), the movement amplitude was found to decrease with the inhibitory repetitive transcranial magnetic stimulation, while the movement velocity respectively increased and decreased with the facilitatory and inhibitory repetitive transcranial magnetic stimulation. These results confirmed the modulating effects of repetitive transcranial magnetic stimulation on kinesthetic perception in a single experimental paradigm.

Publisher's Note: Explosive percolation transitions in growing networks [Phys. Rev. E 93, 032316 (2016)]

This corrects the article DOI: 10.1103/PhysRevE.93.032316.

Explosive percolation transitions in growing networks

Recent extensive studies of the explosive percolation (EP) model revealed that the EP transition is second order with an extremely small value of the critical exponent β associated with the order parameter. This result was obtained from static networks, in which the number of nodes in the system remains constant during the evolution of the network. However, explosive percolating behavior of the order parameter can be observed in social networks, which are often growing networks, where the number of nodes in the system increases as dynamics proceeds. However, extensive studies of the EP transition in such growing networks are still missing. Here we study the nature of the EP transition in growing networks by extending an existing growing network model to a general case in which m node candidates are picked up in the Achiloptas process. When m = 2, this model reduces to the existing model, which undergoes an infinite-order transition. We show that when m ≥ 3, the transition becomes second order due to the suppression effect against the growth of large clusters. Using the rate-equation approach and performing numerical simulations, we also show that the exponent β decreases algebraically with increasing m, whereas it does exponentially in a corresponding static random network model. Finally, we find that the hyperscaling relations hold but in different forms.

Modified Ilizarov technique for the treatment of forearm deformities in multiple cartilaginous exostoses: case series and literature review

The aim of this study is to evaluate the results of gradual ulnar correction and lengthening using the modified Ilizarov technique for the treatment of forearm deformities in patients with multiple cartilaginous exostoses. We retrospectively reviewed 23 forearms in 16 patients. Three different types of operative procedures were performed: (1) corrective osteotomy and gradual lengthening of the ulna, (2) corrective osteotomy of the radius, and (3) excision of exostoses. We evaluated the radiographs; range of motion of the wrist, forearm, and elbow; and functional status using a questionnaire before and after operation. During the clinical interview, post-operative functional status was significantly improved than pre-operative functional status, 12 patients stated that they had no difficulty in performing daily activities, 11 patients stated that they had no pain, and 11 patients stated that the post-operative appearance of the operated forearm was satisfactory. At time of final follow-up, the mean range of motion of the wrist in ulnar/radial deviation, forearm pronation/supination was significantly improved. Also, the radiographic parameters including radial articular angle, carpal slip, radial bowing, and ulnar variance were significantly improved at time of final follow-up. In conclusion, we achieved successful clinical and radiological outcomes in our patients with forearm deformities after treatment with the modified Ilizarov method. However, there could be a recurrence of ulnar shortening and deformity during growth periods in skeletally immature patients.

Detection and characterization of intracranial aneurysms with 16-channel multidetector row CT angiography: a prospective comparison of volume-rendered images and digital subtraction angiography

BACKGROUND AND PURPOSE

The aim of our study was to compare multidetector row CT angiography (MDCTA) with digital subtraction angiography (DSA) in the detection and characterization of intracranial aneurysms.

MATERIALS AND METHODS

In our blinded prospective study, 85 patients with suspected intracranial aneurysm (47 women, 38 men; age range, 19-83 years) underwent both 16-channel MDCTA and DSA. The MDCT angiograms were interpreted for the presence, location, size, ratio of the neck to the dome (N/D ratio), and lobularity of the aneurysms and relationship of the aneurysm with the adjacent arterial branches, by using volume-rendering techniques. MDCTA and DSA images (reference standard) were interpreted by 2 independent readers, and the results were compared.

RESULTS

A total of 93 aneurysms were detected at DSA in 71 patients, whereas no aneurysms were detected in 14 patients. Compared with DSA, the overall sensitivity, specificity, and accuracy of MDCTA on a per-aneurysm basis were 92.5%, 93.3%, and 92.6%, respectively, for both independent readers. For aneurysms of <3 mm, however, MDCTA had a sensitivity of 74.1% for reader 1 and 77.8% for reader 2. There was excellent agreement between readers in the detection of aneurysms (kappa = 0.822). In addition, MDCTA was also accurate in determining N/D ratio of aneurysms, aneurysm lobularity, and adjacent arterial branches.

CONCLUSION

MDCTA is accurate in the detection and characterization of intracranial aneurysms and can be used as a reliable alternative imaging technique to DSA in selected cases.

Surgical Outcome of Endoscopic Carpal Tunnel Release in 100 Patients with Carpal Tunnel Syndrome

The purpose of this study is to present the surgical outcome of endoscopic carpal tunnel release (ECTR) for the treatment of carpal tunnel syndrome (CTS). One hundred and thirty-one procedures (36 right hands, 33 left hands and 31 bilateral hands) of single portal ECTR were performed upon 100 patients (age range: 36-77 years, mean age: 52.9 years; 98 women and 2 men) with electrodiagnostically proven CTS for 2.5 years from 2001. Preoperative clinical severity and results of electrodiagnostic studies were compared with surgical outcomes at the minimal 3-month postoperative period. Among 131 cases 125 (95.4 %) with complete or significant relief of symptoms were satisfied and 6 (4.6 %) with partial or no relief of symptoms were dissatisfied. There were 2 cases of major complications (one with ulnar nerve injury and the other with ulnar artery injury) that developed in our early experience of ECTR and 1 case of recurrence. The grade of electrodiagnostic abnormalities was associated with surgical outcome but there was no statistical significance between them. The severity of clinical findings, age at onset and symptom duration were not correlated with surgical outcome. In conclusion, ECTR surgery was effective in relieving the symptoms of CTS with a low complication rate after the learning curve period. Thus, ECTR can be an alternative to the traditional open surgery and can be the first procedure for CTS with several advantages over open methods.

Human neutrophil lactoferrin trans-activates the matrix metalloproteinase 1 gene through stress-activated MAPK signaling modules

It has been proposed that human neutrophil lactoferrin (Lf) could be involved in gene expression as a DNA-binding protein after its translocation into the nucleus. However, the molecular basis of Lf action has not been defined, and Lf-regulated target genes have not been identified. We report here that overexpressed Lf functions as a specific trans-activator of matrix metalloproteinase 1 (MMP1) gene, and that induction of this AP-1-responsive gene is mediated via the stress-activated MAPK signaling modules. Transactivation of the MMP1 promoter by overexpressed Lf requires the presence of an AP-1 binding site. In gel shift experiments, Lf did not interact directly with AP-1-containing fragments of the MMP1 promoter. However, nuclear extracts from Lf-expressing cells contained increased levels of proteins that bound to AP-1 elements. This Lf-induced AP-1 DNA binding activity was reduced by a p38 MAPK inhibitor. Inhibitors of the MEK kinases had little effect on Lf-induced AP-1. However, expression of dominant-negative MKK4 or JNK1 inhibited Lf-induced gene expression. The JNK activity stimulated by Lf correlates with the enhanced AP-1 binding ability. These findings demonstrate that the Lf-induced activation of AP-1 is mediated via JNK and p38 MAPK pathways.

Quantitative assessment of estrogenic activity in the water environment of Korea by the E-SCREEN assay

In this study, the E-SCREEN assay was optimized and validated for the sensitive quantitative determination of the total estrogenicity in river samples. River water and sediment samples were collected and analyzed with the E-SCREEN. River water (10 l) was extracted using combined solid-phase extraction in static adsorption mode with Soxhlet extraction. Estrogenic pollutants adsorbed to the XAD-4 resin were recovered with 98.24 +/- 5.90% efficiency by elution with ethyl acetate and dichloromethane (1:9). The detection limit by 17beta-estradiol equivalent concentration (EEQ) of the E-SCREEN assay was 8.03 pg EEQ/l. Among the water samples, the estrogenic activity was observed to be higher downstream of the Kumho river (7.43 ng EEQ/l) and upstream of Kum river (2.05 ng EEQ/l) than in other samples. More than 3 mg of equivalent sediment samples from the Kumho river, Kum river and Miho stream showed partial agonistic effects, and the Mankyung river showed a partial agonistic effect with only 1.5 mg of sediment. The highest value of RPE was 83.34 downstream of the Kumho river, and the lowest value of RPE was 6.52 downstream of the Miho stream. Full estrogen agonistic activities were observed downstream of the Kumho river and upstream of the Kum river. The partial agonistic activity was observed in upstream of the Kumho river, downstream of the Mankyung river, and upstream of the Miho stream, and no agonistic action was observed downstream of the Kum river or Miho stream, or upstream of the Mankyung river. The total estrogenic activity in the river water and sediment samples was between 0.50 pg/L and 7.4 ng/L, 3.39 pg/g and 10.70 pg/g.

No significant correlation exists between core promoter mutations, viral replication, and liver damage in chronic hepatitis B infection

Hepatitis B virus (HBV) core promoter mutants have been proposed to contribute to severe liver damage by increasing viral loads, but this has not yet been clearly shown. To examine the effects of core promoter mutants on viral load and liver damage, we first developed a polymerase chain reaction (PCR)-based semiquantitative HBV DNA detection method with a high sensitivity (able to detect as low as 10(3) molecules/mL). Then we cloned 12 predominant core promoter mutants from 41 chronic hepatitis B patients. The in vitro promoter and replication activities of these mutants were similar to those of wild-type virus. However, viral load was highly variable, and this was dependent on individual patients rather than mutant type. In addition, there was no mutant type that showed any unique correlation with alanine transaminase (ALT) levels. Viral load was not significantly correlated with ALT level in both cross-sectional and longitudinal studies. Quantitation of HBV levels also revealed no clear correlation between hepatitis B e antigen (HBeAg) status and viral load. Taken together, these results indicated that the replication activity of core promoter mutants has little effect on viral load, and that viral load does not correlate with the severity of liver damage or with HBeAg status.

Molecular mechanism of staurosporine-induced apoptosis in osteoblasts

Staurosporine, a microbial alkaloid, is a strong inhibitor of protein kinases. We induced apoptosis in murine osteoblast MC3T3E-1 cells by exposure to the staurosporine. Staurosporine transiently increased the phosphotransferase activity of c-Jun N-terminal kinase-1 (JNK1), which in turn may activate the transcriptional activity of activating protein-1 (AP-1). We then prepared extracts from staurosporine-treated MC3T3E-1 cells and monitored the cleavage of acetyl-YVAD-AMC and acetyl-DEVD-AMC, fluorogenic substrates of caspase-1-like and caspase-3-like proteases, respectively. Staurosporine caused a significant increase in the proteolytic activity of caspase-3-like proteases, but not in the activity of caspase-1-like proteases. Furthermore, staurosporine increased the transcriptional activity of nuclear factor- kappa B (NF- kappa B). These data suggest that staurosporine-induced apoptosis in osteoblasts may occur via activation of JNK1, caspase-3-like proteases, and transcriptional factors including AP-1 and NF- kappa B.

The regulatory mechanism of phosphatidylinositol 3-kinase by insulin in 3T3 L1 fibroblasts: phosphorylation-independent activation of phosphatidylinositol 3-kinase

Phosphatidylinositol (PI) 3-kinase plays an important role in transducing the signals of various growth factor receptors. However, the regulatory mechanism of PI3-kinase activity by these growth factor receptors is not completely understood. Therefore, we attempted to clarify the regulatory mechanism of PI3-kinase using insulin and 3T3 L1 fibroblasts. Our results showed that insulin stimulated PI3-kinase activity seven-fold and concomitantly phosphorylated a p85 subunit at the tyrosine residue. However, this tyrosine phosphorylation was not significant in the activation of PI3-kinase as the PI3-kinase pulled down by the overexpressed GST-p85 fusion protein showed as high an activity as the immunoprecipitated one. The p110 subunit was phosphorylated at both serine and tyrosine residues without insulin treatment. Since the phosphorylation state was not changed by insulin. The results suggested that phosphorylation of the p110 subunit does not control PI3-kinase activity. Finally, it was shown that the insulin receptor substrate-1 (IRS-1) binding to PI3-kinase was not sufficient for full activation because the amount of IRS-1 pulled down by the GST-p85 fusion protein reached almost maximum, after incubation with insulin-treated cell lysates for 20 min, whereas PI3-kinase activity reached its maximum only after incubation for 5 h. All results suggest that the phosphorylation of p85 subunit at tyrosine residues and phosphorylation of p110 subunit at tyrosine or serine residues are not functionally significant in the regulation of PI3-kinase activity. They also suggest that P13-kinase is needed to bind to other protein(s) as well as the insulin receptor substrate-1 for full activation.

Evaluation of an activated carbon felt passive sampler in monitoring organic vapors

Using an activated carbon felt (ACF, KF-1600), the applicability of an ACF passive sampler in monitoring organic vapors was evaluated. The evaluated results of the ACF passive sampler were compared with those of a 3 M (Model 3500) passive sampler. At low-humidity condition (8 +/- 3% RH), the sampling rates of the ACF passive sampler for volatile organic vapors were within the range of +/-25% from the results of a charcoal tube, which was the reference method recommended by NIOSH. However, at high humidity condition (90 +/- 5% RH), even though the sampling rates for toluene, MIBK, and PCE were within the range of +/-25%, the sampling rates of ACF sampler for n-hexane and MEK decreased steeply with time after being high at the beginning of the exposure time. Under this condition, the sampling rate of the 3 M passive sampler for MEK was also high at the beginning of the exposure time. In case of the ACF passive sampler, the sampling rates of the relatively strong adsorbates such as toluene, MIBK, and PCE were much less affected by humidity than those of n-hexane and MEK which were weak adsorbates.

Primers determine the sensitivity of PCR-mediated hepatitis B virus DNA detection and pretreatment of PCR mixture with 8-methoxypsoralen eliminates false-positive results

Most methods for the diagnosis of hepatitis B virus (HBV) infection largely depend on viral DNA detection by polymerase chain reaction (PCR) or radioimmunological assay of viral antigens or antibodies. The quality assurance program recently established in Europe reported that PCR-mediated HBV DNA detection methods used in many laboratories produced a high rate of false-positive and false-negative results. Thus, we attempted to improve the conditions of current PCR methods for detection of HBV DNA. In the present study, we applied a recently developed method of releasing HBV DNA from virion by NaOH treatment of patient serum. Using four different primer sets specific to the HBV core region, we found that the sensitivity of first-round PCR can be improved by more than two orders of magnitude depending on the primers. The second round of PCR using nested primers was sensitive enough to detect up to 10(-6) pg of the HBV DNA, which is equivalent to approximately 3 copies of the HBV genome. Among the approximately 800 HBV-infected patient sera investigated in our laboratory, more than 60% of the tested samples gave positive results in the first-round PCR. The rate of positive results obtained using our experimental conditions is very high in comparison with other reports. The reamplification of the first-round PCR reaction mixture with the nested primers produced practically 100% positive results. For diagnosis of HBV infection, we routinely used 1 microliter of patient serum, which was found to be optimum in our laboratory. Surprisingly, from 20% of our positive results, even serum diluted to 1/100 (0.01 microliter) produced a stronger signal than 1 microliter. This observation suggests that direct PCR amplification of HBV DNA released from serum by NaOH treatment has to be compensated by other DNA detection methods for correct quantitation. In order to eliminate the false positive signal resulting from the carry-over due to massive screening of a large number of samples, PCR reaction mixture containing 8-methoxypsoralen was exposed to ultraviolet light prior to thermal cycle amplification. This exercise did not decrease the sensitivity of the detection method, but almost completely removed the false positive results caused by contaminated templates. We are in the process of improving PCR-mediated HBV DNA detection methods to attain more reliable and easily applicable methods.

Exogenous pulmonary surfactant replacement therapy in a neonate with pulmonary hypoplasia accompanying congenital diaphragmatic hernia--a case report

Pulmonary hypoplasia(PH) commonly occurs in association with oligohydramnios and other congenital anomalies, especially congenital diaphragmatic hernia (CDH). Pulmonary hypoplasia is an important factor, as persistent pulmonary hypertension, in the prognosis of CDH. In some reports, there is a decrement of pulmonary surfactant in PH accompanying CDH. Recently, there are some reports that exogenous pulmonary surfactant therapy is effective in experimental animal model and neonatal respiratory distress with PH. We report a case of a 5 day-old male neonate, who had shown dyspnea and diagnosed as left pulmonary hypoplasia accompanying CDH. The CDH was surgically treated and the ipsilateral PH, with intratracheal administration of exogenous pulmonary surfactant postoperatively. After exogenous pulmonary surfactant application, the left lung volume was increased on chest roentgenogram and lung perfusion scan findings, and there was an improvement in oxygenation and clinical manifestations. We suggest that postoperative exogenous pulmonary surfactant replacement therapy is effective in the case of PH and further trials are needed to clarify the optimal dose and timing of supplementation of surfactant for treatment of infants with PH accompanying CDH.

The first documentation of Li-Fraumeni syndrome in Korea

Li-Fraumeni syndrome(LFS) is an autosomal dominant disorder that predisposes individuals to multiple forms of cancer including breast cancer, soft tissue sarcoma, brain tumor, osteosarcoma, leukemia, and adrenocortical carcinoma. Recently, germ-line mutation of the p53 tumor suppressor gene has been implicated in this familial disorder. We report a case of a 25-year old woman who presented with bilateral breast cancer and uterine leiomyoma. Her mother had died of early-onset bilateral breast cancer. And her younger sister had breast carcinoma as well, which was identified at the age of 22, indicating her strong familial history. To test for the presence of the p53 germ-line mutation, we analyzed the genomic DNA from the peripheral blood of the proband and her sister by PCR-SSCP analysis of exon 5 through exon 8 of the p53 gene. As a result, a p53 mutation in exon 7 was detected in an allele, and it was shared with her sister as the same pattern. Sequencing analysis determined the altered nucleotide at codon 248(CGG > TGG) which is one of the most frequent mutation sites related to LFS. Therefore, this patient has the most consistent characteristic features of LFS phenotype and it is believed that this case is the first report of a family with Li-Fraumeni syndrome carrying the p53 germ-line mutation in Korea.

Interaction between free radicals and excitatory amino acids in the formation of ischemic brain edema in rats

Both oxygen free radicals and excitatory amino acids have been implicated as important cellular toxins in ischemic brain. Recent in vitro studies suggest that there may be a mutual interaction between these two mediators. We explored the relation between oxygen free radicals and excitatory amino acids in the development of ischemic brain edema in vivo. Male Sprague-Dawley rats were treated with the free radical scavenger dimethylthiourea 1 hour before ischemia or with the excitotoxin antagonist MK-801 30 minutes before ischemia produced by occlusion of the middle cerebral artery. Groups of seven or eight animals were treated with vehicle, low-dose (375 mg/kg) dimethylthiourea, high-dose (750 mg/kg) dimethylthiourea, low-dose (0.5 mg/kg) MK-801, high-dose (2.0 mg/kg) MK-801, or both high-dose dimethylthiourea and low-dose MK-801. After 4 hours of ischemia, brain water content was determined. In eight vehicle-treated controls, mean +/- SEM water content of tissue in the center of the ischemic zone was 83.29 +/- 0.18%. A significant reduction of brain edema was observed in all drug-treated groups: for example, 50.2% (p less than 0.001) in the high-dose dimethylthiourea group, 53.7% (p less than 0.001) in the low-dose MK-801 group, and 66.4% (p less than 0.001) in the combined dimethylthiourea and MK-801 group. Combined treatment with dimethylthiourea and MK-801 provided no significant additive effect over that resulting from treatment with MK-801 alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Audit of ranitidine administration in parenteral nutrient solutions

An audit of the use of ranitidine administered in parenteral nutrient (PN) solutions is reported. Pharmacists at a 747-bed teaching institution developed criteria addressing justification of the use of ranitidine in PN solutions, process indicators for monitoring, and outcome measures. All patients who received ranitidine in their PN solutions between October 29 and November 22, 1989, were included in the study. Data were collected on a standardized form. A total of 23 evaluable patients received ranitidine in PN solutions during the study period. No inappropriate uses of ranitidine were identified. Patients with renal impairment tended to be underdosed. There were no duplicate administrations of ranitidine by the i.v. minibag and PN solution routes. However, on four occasions the PN solution was interrupted for more than six hours; additional ranitidine by i.v. minibag was ordered for only one of these patients. Testing of nasogastric aspirates for pH was not performed in 17 of the 22 patients who needed this test. Gastrointestinal bleeding was observed in two patients, both of whom were not monitored for gastric pH and were underdosed. A program is being developed to promote the safe and effective use of ranitidine administered in PN solutions. An audit of the administration of ranitidine in PN solutions showed that the drug is usually used appropriately at the institution and that most of the patients had positive clinical outcomes.

Retroperitoneal teratoma with predominance of nephroblastic elements--a case report

The morphological features of a retroperitoneal teratoma in a 10-month-old girl are reported. Unlike the usual pattern of the teratoma, this tumor was composed predominantly of nephroblastomatous tissue. Histologically, glomeruloid and tubular structures were identified in nests of undifferentiated blastemal elements. Hyaline cartilage, adipose tissue, glial tissue and glands lined by mucin-secreting columnar epithelium were minor elements. A focal cystic structure lined by thin flattened epithelium was also noted. Retroperitoneal teratoma with predominance of nephroblastic elements is of interest not only because of its rarity but also because it needs to be differentiated from extrarenal Wilms' tumor, since both of these tumors have different origins.

Increased durability of optical fiber through the use of compressive cladding

Durable fibers having a thin Ti-doped silica surface layer were fabricated by using the refined fabrication process of compressive cladding. High surface-compressive stresses up to 0.69 GPa (100 kpsi) resulted in significant improvement in fatigue resistance of optical-fiber waveguides.