107 research outputs found
DEL ์ ํ๊ตฌ์ ์ํ ํญ-D ๋์ข ๋ฉด์ญ
Extremely weak D variants called DEL are serologically detectable only by adsorption-elution techniques. A nucleotide change of exon 9 in RHD gene, RHD (K409K, 1227G>A) allelic variant is present in almost all the DEL individuals of East Asians. No DEL phenotype has yet been shown to induce a primary alloanti-D immunization in East Asia. A 68-yr-old D-negative Korean man was negative for anti-D at admission, and he developed alloanti-D after transfusion of red blood cells (RBC) from 4 apparently D-negative donors. Four donors who typed D-negative by routine serologic test were analyzed by real-time PCR for RHD gene and RHD (K409K). One donor was found to have RHD (K409K), This is the first case in which DEL RBCs with RHD (K409K) induced a primary alloanti-D immunization in Asian population. Because the DEL phenotype can induce an anti-D immunization in D-negative recipients, further discussion is needed whether RhD negative donors should be screened by molecular method and what an efficient genotyping method is for detecting the RHD gene carriers in Korea. (Korean J Lab Med 2009;29:361-5)Polin H, 2009, TRANSFUSION, V49, P676, DOI 10.1111/j.1537-2995.2008.02046.xFlegel WA, 2009, TRANSFUSION, V49, P465, DOI 10.1111/j.1537-2995.2008.01975.xSun CF, 2008, ANN CLIN LAB SCI, V38, P258Richard M, 2007, TRANSFUSION, V47, P852, DOI 10.1111/j.1537-2995.2007.01199.xLuettringhaus TA, 2006, TRANSFUSION, V46, P2128, DOI 10.1111/j.1537-2995.2006.01042.xYasuda H, 2005, TRANSFUSION, V45, P1581, DOI 10.1111/j.1537-2995.2005.00579.xWagner T, 2005, TRANSFUSION, V45, P520Gassner C, 2005, TRANSFUSION, V45, P527Kim JY, 2005, TRANSFUSION, V45, P345WAGNER FF, 2001, BMC GENET, V2, P10Avent ND, 2000, BLOOD, V95, P375Aubin JT, 1997, BRIT J HAEMATOL, V98, P356Okuda H, 1997, J CLIN INVEST, V100, P373Avent ND, 1997, BLOOD, V89, P2568HWANG YS, 1996, KOREAN J BLOOD TRANS, V7, P233DANIELS G, 1995, HUMAN BLOOD GROUPSMAK KH, 1993, TRANSFUSION, V33, P348LINCHU M, 1988, TRANSFUSION, V28, P350
Human Heart Rhythms Synchronize While Co-sleeping
Human physiological systems have a major role in maintenance of internal stability. Previous studies have found that these systems are regulated by various types of interactions associated with physiological homeostasis. However, whether there is any interaction between these systems in different individuals is not well-understood. The aim of this research was to determine whether or not there is any interaction between the physiological systems of independent individuals in an environment where they are connected with one another. We investigated the heart rhythms of co-sleeping individuals and found evidence that in co-sleepers, not only do independent heart rhythms appear in the same relative phase for prolonged periods, but also that their occurrence has a bidirectional causal relationship. Under controlled experimental conditions, this finding may be attributed to weak cardiac vibration delivered from one individual to the other via a mechanical bed connection. Our experimental approach could help in understanding how sharing behaviors or social relationships between individuals are associated with interactions of physiological systems
A Multiinstitutional Consensus Study on the Pathologic Diagnosis of Endometrial Hyperplasia and Carcinoma
BACKGROUND: The purpose of this study was to examine the reproducibility of both the diagnosis of endometrial hyperplasia (EH) or adenocarcinoma, and the histologic grading (HG) of endometrioid adenocarcinoma (EC). METHODS: Ninety-three cases of EH or adenocarcinomas were reviewed independently by 21 pathologists of the Gynecologic Pathology Study Group. A consensus diagnosis was defined as agreement among more than two thirds of the 21 pathologists. RESULTS: There was no agreement on the diagnosis in 13 cases (14.0%). According to the consensus review, six of the 11 EH cases (54.5%) were diagnosed as EH, 48 of the 57 EC cases (84.2%) were EC, and 5 of the 6 serous carcinomas (SC) (83.3%) were SC. There was no consensus for the 6 atypical EH (AEH) cases. On the HG of EC, there was no agreement in 2 cases (3.5%). According to the consensus review, 30 of the 33 G1 cases (90.9%) were G1, 11 of the 18 G2 cases (61.1%) were G2, and 4 of the 4 G3 cases (100.0%) were G3. CONCLUSIONS: The consensus study showed high agreement for both EC and SC, but there was no consensus for AEH. The reproducibility for the HG of G2 was poor. We suggest that simplification of the classification of EH and a two-tiered grading system for EC will be necessary.This study was partly supported by research fund of Chungnam National University in 2007
Detection of apneic events from single channel nasal airflow using 2nd derivative method
Detection of sleep apnea is one of the major tasks in sleep studies. Several methods, analyzing the various features of bio-signals, have been applied for automatic detection of sleep apnea, but it is still required to detect apneic events efficiently and robustly from a single nasal airflow signal under varying situations. This study introduces a new algorithm that analyzes the nasal airflow (NAF) for the detection of obstructive apneic events. It is based on mean magnitude of the second derivatives (MMSD) of NAF, which can detect respiration strength robustly under offset or baseline drift. Normal breathing epochs are extracted automatically by examining the stability of SaO(2) and NAF regularity for each subject. The standard MMSD and period of NAF, which are regarded as the values at the normal respiration level, are determined from the normal breathing epochs. In this study, 24 Polysomnography (PSG) recordings diagnosed as obstructive sleep apnea (OSA) syndrome were analyzed. By analyzing the mean performance of the algorithm in a training set consisting of three PSG recordings, apnea threshold is determined to be 13% of the normal MMSD of NAF. NAF signal was divided into 1-s segments for analysis. Each segment is compared with the apnea threshold and classified into apnea events if the segment is included in a group of apnea segments and the group satisfies the time limitation. The suggested algorithm was applied to a test set consisting of the other 21 PSG recordings. Performance of the algorithm was evaluated by comparing the results with the sleep specialist's manual scoring on the same record. The overall agreement rate between the two was 92.0% (kappa=0.78). Considering its simplicity and lower computational load, the suggested algorithm is found to be robust and useful. It is expected to assist sleep specialists to read PSG more quickly and will be useful for ambulatory monitoring of apneas using airflow signals.This work was supported by the Korean Science and Engineering Foundation under the Advanced Biometric Research Center Program
Mechanical Properties of Titania Nanofiber Mats Fabricated by Electrospinning of Sol--gel Precursor
Flexible mats of titania fibers are prepared by calcination of electrospun polyvinylpyrrolidone fibers containing titanium isopropoxide precursor. Structural investigation of the calcinated nanofibers by X-ray diffraction (XRD) and electron diffraction (ED) combined with the morphologies by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show the titania fibers, with an average diameter of 180 nm, were comprised of anatase and rutile crystals. The mechanical, chemical and thermal properties of the titania fiber mats are further investigated by the techniques of Instron mechanical tester, thermogravimetric analyzer (TGA), and Fourier transform infrared spectroscopy (FT-IR). The titania fiber mat prepared in this method exhibited a significant flexibility with 461 MPa Youngโs modulus
Abrupt increase in heart rate during the transition from non-REM sleep to wakefulness and its utility for estimating sleep stages
Since fluctuation of heart rate (HR) reflects the activation of the
autonomic nervous system (ANS) and ANS activity varies during sleep
according to the depth of sleep, HR variation is known to reflect the
change of sleep stages. However, it has been very difficult to estimate
the sleep stage transitions beyond a certain degree of accuracy with HR
only. If we can estimate sleep stage transition with higher accuracy by HR only, it will be clinically very useful. Therefore, we devised a
method for estimating the sleep stage transition from non-REM sleep
to a state of wakefulness based on the abrupt HR increase.
Electrocardiogram data were collected from 12 normal volunteers
(8 males and 4 females; age 27ยฑ2.34 years) during the whole night
polysomnography (PSG). Then, we detected the episodes of abrupt
HR increase for the whole night. Signal processing was used to
compensate for the slow fluctuation of HR during sleep and a
threshold was applied for the detection of abrupt HR increase. We
compared the result with the sleep stage findings read by the experts
from PSG with the standard method.
In contrast to other transitions among sleep stages, transitions
from any non-REM sleep stage to wakefulness showed significant HR
increase. The accuracy of the detection of transition to wakefulness
from non-REM sleep was 97ยฑ0.02%, using HR signal only. However,
HR did not remain in the increased state through the wakefulness,
but returned to the baseline rate slowly with adaptation. Therefore,
we found it difficult to estimate the extended wakefulness state with
HR only. During REM sleep, with HR generally higher than in non-
REM sleep, we also found it difficult to estimate the transition to
wakefulness using the HR increase criteria. In this study, we found
that there tends to be an abrupt HR increase in the transition of non-
REM sleep stage to wakefulness and it could be reliably used to
estimate the transition. The observed HR increase between non-REM
sleep and wakefulness seems to be caused by sudden sympathetic
activation from the parasympathetic dominance.
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