OBJECTIVES: Acceleration plethysmograms (APGs) are obtained by taking the second derivative of photoplethysmograms (PPGs) and are noninvasive circulatory signals related to risk factors for atherosclerosis with age. There has been growing interest in the development of mobile devices to collect and analyze PPG single features for ambulatory health monitoring. The present study aimed to extract a new feature from the morphologies of APG and PPG signals to classify the dominant indices related to the pulsatile volume of blood in tissue according to age. METHODS: Ten APG and 14 PPG indices were simultaneously extracted. All indices were compared via Pearson correlation coefficients (r) and a regression analysis. We introduced a combined index extracted from both the PPG and APG indices defined as the inflection point area plus the d_peak (IPAD). The participants included 93 healthy adults aged 36–86 years with a mean ± standard deviation age of 57.43 ± 11.99 years. RESULTS: The d_peak and age index for the APG indices were significantly correlated with age (r = −0.408, p < 0.0001 and r = 0.296, p = 0.0039, respectively). Only the A1 time for PPG indices was moderately correlated with age (r = −0.247, p = 0.017). The stiffness index, including individual height information, was not related to age (r = −0.031, p = 0.7713). However, the combined IPAD index was significantly more correlated with age (r = 0.56, p < 0.001) than the other indices. CONCLUSIONS: The proposed index outperformed the other 24 indices for evaluating vascular aging. We suggest that the IPAD is a significant factor related to the clinical information embedded in the PPG waveform.
Acceleration* ; Adult ; Aging* ; Atherosclerosis ; Humans ; Photoplethysmography ; Risk Factors ; Vascular Stiffness

OBJECTIVES: Acceleration plethysmogram (APG) obtained from the second derivative of photoplethysmography (PPG) is used to predict risk factors for atherosclerosis with age. This technique is promising for early screening of atherosclerotic pathologies. However, extraction of the wave indices of APG signals measured from the fingertip is challenging. In this paper, the development of a wave detection algorithm including a preamplifier based on a microcontroller that can detect the a, b, c, and d wave indices is proposed. METHODS: The 4th order derivative of a PPG under real measurements of an APG waveform was introduced to clearly separate the components of the waveform, and to improve the rate of successful wave detection. A preamplifier with a Sallen-Key low pass filter and a wave detection algorithm with programmable gain control, mathematical differentials, and a digital IIR notch filter were designed. RESULTS: The frequency response of the digital IIR filter was evaluated, and a pulse train consisting of a specific area in which the wave indices existed was generated. The programmable gain control maintained a constant APG amplitude at the output for varying PPG amplitudes. For 164 subjects, the mean values and standard deviation of the a wave index corresponding to the magnitude of the APG signal were 1,106.45 and +/-47.75, respectively. CONCLUSIONS: We conclude that the proposed algorithm and preamplifier designed to extract the wave indices of an APG in real-time are useful for evaluating vascular aging in the cardiovascular system in a simple healthcare device.
Acceleration* ; Aging ; Atherosclerosis ; Cardiovascular System ; Delivery of Health Care ; Mass Screening ; Pathology ; Photoplethysmography ; Risk Factors ; Vascular Stiffness

OBJECTIVES: Recent studies have emphasized the potential information embedded in peripheral fingertip photoplethysmogram (PPG) signals for the assessment of arterial wall stiffening during aging. For the discrimination of arterial stiffness with age, the brachial-ankle pulse wave velocity (baPWV) has been widely used in clinical applications. The second derivative of the PPG (acceleration photoplethysmogram [APG]) has been reported to correlate with the presence of atherosclerotic disorders. In this study, we investigated the association among age, the baPWV, and the APG and found a new aging index reflecting arterial stiffness for a healthcare device. METHODS: The APG and the baPWV were simultaneously applied to assess the accuracy of the APG in measuring arterial stiffness in association with age. A preamplifier and motion artifact removal algorithm were newly developed to obtain a high quality PPG signal. In total, 168 subjects with a mean +/- SD age of 58.1 +/- 12.6 years were followed for two months to obtain a set of complete data using baPWV and APG analysis. RESULTS: The baPWV and the B ratio of the APG indices were correlated significantly with age (r = 0.6685, p < 0.0001 and r = -0.4025, p < 0.0001, respectively). A regression analysis revealed that the c and d peaks were independent of age (r = -0.3553, p < 0.0001 and r = -0.3191, p < 0.0001, respectively). CONCLUSIONS: We determined the B ratio, which represents an improved aging index and suggest that the APG may provide qualitatively similar information for arterial stiffness.
Aging* ; Artifacts ; Delivery of Health Care* ; Discrimination (Psychology) ; Photoplethysmography* ; Pulse Wave Analysis* ; Vascular Stiffness

BACKGROUND: It is very important for hemodialysis in patients with end stage renal disease to obtain vascular access that resists repeated punctures and maintains adequate blood flow. This study was designed to indentify factors that may influence early patency rate of autogenous arteriovenous fistula. MATERIAL AND METHOD: 49 cases in 47 patients who underwent radiocephalic fistula formation in our hospital from June 2002 through May 2003 were reviewed and analyzed. RESULT: The early patency rate was 79.6%. Age, sex, hypertension, and diabetes mellitus were not significant factors for patency. Body mass index and duration of hypertension and diabetes did not influence the early results either. Cephalic vein diameter measured preoperatively and blood flow at radiocephalic fistula were significantly positive correlative factors. Groups with the vein diameter less than 2.7 mm, or with the blood flow less than 100 mL/min had significantly lower early patency rate than the other groups. CONCLUSION: To improve early patency rate of radiocephalic fistula, large sized cephalic vein should be selected and if the intraoperative flow at radiocephalic fistula is less than 100 mL/min, another arteriovenous fistula formation should be considered.
Arteriovenous Fistula* ; Body Mass Index ; Diabetes Mellitus ; Fistula ; Humans ; Hypertension ; Kidney Failure, Chronic ; Punctures ; Renal Dialysis* ; Veins

PURPOSE: p53 mutations are one of the most common genetic alterations in human lung cancer. Although the prognostic value of mutant p53 is still debated, it is widely accepted as a relatively early genetic event in the development and progression of lung cancer. Moreover, there are growing reports about an association between smoking and p53 mutation, suggesting that the p53 gene could be a target of the smoking associated carcino- genesis in the lung cancer. MATERIALS AND METHODS: Surgically resected 89 primary non-small cell lung cancers were obtained from May of 1995 to May of 1997. p53 expression and Ki-67 expression were measured by immunohistochemistry, and each p53 expression and smoking amount were compared with Ki-67 expression and other clinical prognostic factors. RESULTS: Positive p53 expressions were found in 52 (58%) specimens, including 38 (69%) squamous cell carcinomas, 11 (39%) adenocarcinomas, and 3 (50%) large cell carcinomas, and closely associated with male and squamous cell carcinoma. Also close correlation was observed between smoking amount and p53 expression by the regression analysis. But p53 and Ki-67 expression showed no associations in pathologic stage and survival, and there was no association between p53 expression and survival after adjuvant radiotherapy. CONCLUSION: Smoking seems to affect p53 mutations in non-small cell lung cancer, and additional efforts are needed to evaluate the carcinogesis of lung cancer.
Adenocarcinoma ; Carcinoma, Large Cell ; Carcinoma, Non-Small-Cell Lung ; Carcinoma, Squamous Cell ; Genes, p53 ; Humans ; Immunohistochemistry ; Lung Neoplasms ; Male ; Radiotherapy, Adjuvant ; Small Cell Lung Carcinoma* ; Smoke* ; Smoking*

BACKGROUND: With the development of cardiac surgical technique, we need more prosthetic materials for repairing the intra- and extracardiac defects. Although bovine pericardial bioprosthesis treated with glutaraldehyde (GA) solution is one of the most popular materials, it has a drawback of later calcific degeneration. The purpose of this study is to investigate the effectiveness of several materials and methods in reducing the calcific degeneration of bovine pericardium. MATERIAL AND METHOD: Forty square-shaped pieces of bovine pericardia were fixed in 0.625% GA solution with 4 g/L MgCl2.6H2O as a control group (group 1). Other 40 pieces pre-treated with 1% SDS (group 2) and 40 pieces post-treated with 8% glutamate (group 3) and 2% chitosan (group 4) were also fixed in the same GA solution. Other 40 pieces pre-treated with 1% SDS and post-treated with 8% glutamate and 40 pieces post-treated with 2% chitosan were also fixed in the same GA solution (group 5, 6). The pericardial pieces were implanted into the belly of 40 Fisher 344 rats subdermally and were extracted 1 month, 2 months, 3 months, and 6 months after the implantation. With an atomic absorption spectrophotometry, we measured the calcium amount deposited and examined the tissue with microscope. RESULT: The calcium deposition in 1 month was less in group 2, 5, 6 than that in group 1 (p<0.05). It was most prominent in group 5 (p<0.01). This finding continued in 2 month. In 3 month, the calcium deposition was less in group 3 and 4 as well as group 2, 5, and 6 than in group 1. In 6 month, the calcium deposition in group 2, 3, 4, 5, and 6 was less than that in group 1 and the difference was more than that of 1, 2, and 6 month. The microscopic calcium deposition was also less in group 2 and 5. Calcium deposition developed in the whole layer of pericardium, beginning with the surrounding the collagen fiber and progressing inwardly. CONCLUSION: Pre-treatment with SDS, post-treatment with glutamate or chitosan, and SDS pre-treatment and post-treatment with glutamate or chitosan were effective in reducing the calcium deposition in bovine pericardium. Moreover, the combined method of SDS pre-treatment and glutamate post-treatment was more effective than other methods.
Animals ; Bioprosthesis ; Calcium ; Chitosan ; Collagen ; Glutamic Acid ; Glutaral ; Heterografts* ; Pericardium ; Rats ; Spectrophotometry, Atomic

A brain-machine interface (BMI) has recently been introduced to research a reliable control of machine from the brain information processing through single neural spikes in motor brain areas for paralyzed individuals. Small, wireless, and implantable BMI system should be developed to decode movement information for classifications of neural activities in the brain. In this paper, we have developed a totally implantable wireless neural signal transmission system (TiWiNets) combined with advanced digital signal processing capable of implementing a high performance BMI system. It consisted of a preamplifier with only 2 operational amplifiers (op-amps) for each channel, wireless bluetooth module (BM), a Labview-based monitor program, and 16 bit-RISC microcontroller. Digital finite impulse response (FIR) band-pass filter based on windowed sinc method was designed to transmit neural signals corresponding to the frequency range of 400 Hz to 1.5 kHz via wireless BM, measuring over -48 dB attenuated in the other frequencies. Less than +/-2% error by inputting a sine wave at pass-band frequencies for FIR algorithm test was obtained between simulated and measured FIR results. Because of the powerful digital FIR design, the total dimension could be dramatically reduced to 23x27x4 mm including wireless BM except for battery. The power isolation was built to avoid the effect of radio-frequency interference on the system as well as to protect brain cells from system damage due to excessive power dissipation or external electric leakage. In vivo performance was evaluated in terms of long-term stability and FIR algorithm for 4 months after implantation. Four TiWiNets were implanted into experimental animals' brains, and single neural signals were recorded and analyzed in real time successfully except for one due to silicon- coated problem. They could control remote target machine by classify neural spike trains based on decoding technology. Thus, we concluded that our study could fulfill in vivo needs to study various single neuron-movement relationships in diverse fields of BMI.
Automatic Data Processing ; Brain ; Brain-Computer Interfaces ; Neural Prostheses ; Organothiophosphorus Compounds ; Signal Processing, Computer-Assisted ; Silanes

Dermatofibrosarcoma protuberans is a rare tumor that occurs in the dermis or subcutaneous tissue of the trunk or extremities in relatively young adults. There are few reports of Dermatofibrosarcoma protuberans associated with pregnancy. We experienced a 28-year-old pregnant female patient with an abdominal wall mass, which grew rapidly during pregnancy. Excisional biopsy was performed and the pathologic diagnosis was fibrosarcoma transformed from Dermatofibrosarcoma protuberans. Dermatofibrosarcoma protuberans showed a positive CD34 immunostaining while fibrosarcoma showed a negative CD34. There was no recurrence or metastasis with the follow up period of 2 years. We report here a rare case of Dermatofibrosarcoma protuberans aggravated during pregnancy with a review of the literature.
Abdominal Wall ; Adult ; Biopsy ; Dermatofibrosarcoma ; Dermis ; Extremities ; Female ; Fibrosarcoma ; Follow-Up Studies ; Humans ; Neoplasm Metastasis ; Pregnancy ; Recurrence ; Subcutaneous Tissue ; Young Adult

Adenosquamous carcinoma arising in congenital choledochal cyst is very rare and herein we report a case thereof. A 37-year-old woman was referred for further evaluation of pancreas head mass and a hepatic nodule on CT. She had been diagnosed with congenital choledochal cyst at 22-years-old and received Roux-en-Y choledochojejunostomy at that time. Endoscopic ultrasonography-guided biopsy proved the pancreas head mass as a squamous cell carcinoma and liver biopsy also proved the liver mass as a metastatic squamous cell carcinoma. We performed pancreaticoduodenectomy and tumorectomy of metastatic liver nodule. Grossly, the primary lesion was located at intrapancreatic portion of choledochal cyst. Histologically, the primary lesion and hepatic nodule was metastatic adenosquamous carcinoma. So far, there have been only three cases of adenosquamous carcinoma arising in congenital choledochal cyst reported in English-language literature. This is another case and the first case reported in Korea.
Adult ; Biopsy ; Carcinoma, Adenosquamous ; Carcinoma, Squamous Cell ; Choledochal Cyst ; Choledochostomy ; Female ; Head ; Humans ; Korea ; Liver ; Pancreas ; Pancreaticoduodenectomy

Sporulated oocysts from the feces of infected cats with Toxoplasma gondii can cause detrimental disease in both humans and animals. To investigate the prevalence of feral cats that excrete T. gondii oocysts in the feces, we examined fecal samples of 563 feral cats over a 3-year period from 2009 to 2011. Oocysts of T. gondii excreted into the feces were found from 4 of 128 cats in 2009 (3.1%) and one of 228 (0.4%) in 2010 while none of the 207 cats in 2010 were found positive with oocysts in their feces, resulting in an overall prevalence rate of 0.89% (5/563) between 2009 and 2011. Among the 5 cats that tested positive with T. gondii oocysts, 4 of the cats were male and 1 was a female with an average body weight of 0.87 kg. Numerous tissue cysts of 60 μm in diameter with thin (<0.5 μm) cyst walls were found in the brain of one of the 5 cats on necropsy 2 months after the identification of oocysts in the feces. A PCR amplification of the T. gondii-like oocysts in the feces of the positive cats using the primer pairs Tox-5/Tox-8 and Hham34F/Hham3R confirmed the presence of T. gondii oocysts in the feces. This study provides a good indication of the risk assessment of feral cats in the transmission of T. gondii to humans in Korea.
Animals ; Body Weight ; Brain ; Cats ; Feces ; Female ; Humans ; Korea ; Male ; Oocysts ; Polymerase Chain Reaction ; Prevalence ; Risk Assessment ; Toxoplasma