The circadian system represents a temporal order which is mediated by the mutual coupling of oscillators and by the synchronizing effects of zeitgebers. It is known that well-being of man depends partly on the maintenance of this order, and that repeated or long lasting disturbances to it such as shift work will cause harmful effects. This study was a quasi-experimental study to test the effect of shift directions for the clinical nurses on the circadian rhythm. Fourteen nurses working at the general units of Y hospital were selected according to the established criteria. Fourteen subjects were assigned to a weekly shift but the directions of shift work were phase delay first and then phase advance or vice versa. Oral temperature, total sleeping time, frequency of sleep-wake cycle, fatigue, mental performance, and physical symptom were measured during these days except holidays. The data collection period was from April 26, 1993 to July 3, 1993. MANOVA and Wilcoxon signed rank test were used for statistical analysis. The results are summarized as follows. 1. Having worked on evening and night shifts in either phase delay or phase advance schedules, temperature rhythms of shift workers were gradually adapted to the new sleep-wake cycles. A complete adaptation to work on the night shift was achieved the sixth day of the night shift in the phase delay schedule compared to the partial adaptation to the work on the night shift in the phase advance schedule. Accordingly, by putting evening shift between day and night shifts, it will be possible for circadian rhythm to adapt easily to the night shift. 2. There were differences in the total sleeping time, frequency of sleep-wake cycle, fatigue, and physical symptom except for mental performance between night shift and day, evening shift. This indicates further that shift workers working on the night shift have a hard time adapting to the shift work compared to the other shifts. 3. Evaluating all the acrophases of temperature rhythm either in phase delay or phase advance schedules, it was shown that night to evening shift in the phase advance schedule revealed the smallest phase move. Also phase advance schedule showed poorer adaptation to shift work than phase delay schedule in connection with total sleeping time, frequency of sleep-wake cycle, fatigue, mental performance, and physical symptom. It is suggested, taken together, these findings reflect that phase delay schedule facilitated the degree of adjustment to the shift work compared to the phase advance schedule.
Appointments and Schedules ; Circadian Rhythm* ; Data Collection ; Fatigue ; Holidays ; Mental Fatigue

BACKGROUND: Hepatitis B virus (HBV) plays well-known roles in tumorigenesis of hepatocellular carcinoma (HCC) in infected patients. However, HBV-associated protein status in tumor tissues and the relevance to tumor behavior has not been reported. Our study aimed to examine the expression of HBV-associated proteins in HCC and adjacent nontumorous tissue and their clinicopathologic implication in HCC patients. METHODS: HBV surface antigen (HBsAg), HBV core antigen (HBcAg), and HBV X protein (HBx) were assessed in 328 HBV-associated HCCs and in 155 matched nontumorous tissues by immunohistochemistry staining. RESULTS: The positive rates of HBsAg and cytoplasmic HBx staining in tumor tissue were lower than those in nontumorous tissue (7.3% vs. 57.4%, p < .001; 43.4% vs. 81.3%, p < .001). Conversely, nuclear HBx was detected more frequently in tumors than in nontumorous tissue (52.1% vs. 30.3%, p < .001). HCCs expressing HBsAg, HBcAg, or cytoplasmic HBx had smaller size; lower Edmondson-Steiner (ES) nuclear grade, pT stage, and serum alpha-fetoprotein, and less angioinvasion than HCCs not expressing HBV-associated proteins. Exceptionally, nuclear HBx-positive HCCs showed higher ES nuclear grade and more frequent large-vessel invasion than did nuclear HBx-negative HCCs. In survival analysis, only nuclear HBx-positive HCCs had shorter disease-free survival than nuclear HBx-negative HCCs in pT1 and ES nuclear grade 1-2 HCC subgroup (median, 126 months vs. 35 months; p = .015). CONCLUSIONS: Our data confirmed that expression of normal HBV-associated proteins generally decreases in tumor cells in comparison to nontumorous hepatocytes, with the exception of nuclear HBx, which suggests that nuclear HBx plays a role in recurrence of well-differentiated and early-stage HCCs.
alpha-Fetoproteins ; Antigens, Surface ; Carcinogenesis ; Carcinoma, Hepatocellular* ; Cytoplasm ; Disease-Free Survival ; Hepatitis B Core Antigens ; Hepatitis B Surface Antigens ; Hepatitis B virus* ; Hepatitis B* ; Hepatitis* ; Hepatocytes ; Humans ; Immunohistochemistry ; Recurrence*

PURPOSE: Although infants with bronchopulmonary dysplasia (BPD) are at risk of developing secondary pulmonary hypertension (PH), which is associated with significant morbidity and mortality, little has been reported about the incidence, clinical course and prognosis of PH secondary to BPD in premature infants. This study was done to investigate the incidence, risk factors, clinical course, and the ultimate prognosis of PH developed secondary to BPD in very low birth weight infants (<1,500 g). METHODS: Medical records of very low birth weight infant (VLBWI) admitted to Samsung Medical Center NICU from January 2000 to July 2007 were reviewed retrospectively. BPD was defined by Jobe's classification. The diagnosis of pulmonary hypertension was established as velocity of tricuspid valve regurgitation (TR) > or =3 m/s and a flattening of the intraventricular septum by conducting Doppler echocardiography. RESULTS: The incidence of pulmonary hypertension was 6% in VLBWI with BPD and it developed in moderate to severe BPD. The diagnosis of pulmonary hypertension was made on postnatal 133 days (range 40-224 days) and the risk factors related to developing pulmonary hypertension were severe BPD, small for gestational age and outborn infants. The mortality rate was 57% and especially higher in severe BPD (70%). The time to recovery spent 3 months (range 1-10 months) in survived patients. CONCLUSION: Based on the results of this research, pulmonary hypertension secondary to BPD in VLBWI related to severity of BPD and had a poor prognosis. We expect that regular long-term echocardiography may be helpful in treating reversible in VLBWI with moderate to severe BPD.
Bronchopulmonary Dysplasia ; Echocardiography ; Gestational Age ; Humans ; Hydrogen-Ion Concentration ; Hypertension, Pulmonary ; Incidence ; Infant ; Infant, Newborn ; Infant, Premature ; Infant, Very Low Birth Weight ; Medical Records ; Prognosis ; Retrospective Studies ; Risk Factors ; Tricuspid Valve Insufficiency

PURPOSE: This study was conducted to determine the incidence, causative pathogens, risk factors and mortality for early onset sepsis in the first three days in very low birth weight infants. METHODS: The medical records of 1,124 very low birth weight infants admitted to the neonatal intensive care unit of Samsung Medical Center between November 1994 and December 2008 were retrospectively reviewed. The incidence, causative pathogens, risk factors, and mortality for early onset sepsis in the first 3 days of life in very low birth weight infants were evaluated. RESULTS: Early onset sepsis, as confirmed by positive blood cultures, was present in 17 of 1,124 infants (1.5%). Sixty-four percent of the isolated pathogens were gram-positive bacteria and 35% of the isolated pathogens were gram-negative bacteria. The dominant pathogens of early onset sepsis included Staphylococcus aureus (23.5%), Esherichia coli (23.5%), and Enterococcus (17.6%). Vaginal delivery (adjusted odds ratio [OR], 3.7; 95% confidence interval [CI], 1.3-10.3; P=0.01) was associated with early onset sepsis. The overall mortality (adjusted hazard ratio, 3.0; 95% CI, 1.4-6.5; adjusted P=0.0039) and mortality within 72 hours of life (adjusted hazard ratio, 6.5; 95% CI, 2.2-18.9; adjusted P=0.0005) of infants with early onset sepsis were higher than that of uninfected infants. CONCLUSION: Early onset sepsis remains an uncommon, but potentially lethal problem among very low birth weight infants. Knowledge of the likely causative organisms and risk factors for early onset sepsis can aid in instituting prompt and appropriate therapy, in order to minimize mortality.
Enterococcus ; Gram-Negative Bacteria ; Gram-Positive Bacteria ; Humans ; Incidence ; Infant ; Infant, Newborn ; Infant, Very Low Birth Weight ; Intensive Care, Neonatal ; Medical Records ; Odds Ratio ; Retrospective Studies ; Risk Factors ; Sepsis ; Staphylococcus aureus

PURPOSE: With improved survival of extremely low birth weight infants (ELBWI), there is an increase in the incidence of necrotizing enterocolitis (NEC) requiring laparotomy, and the risk of morbidity and mortality in these ELBWI is increased. Thus, we determined the prognostic factors in ELBWI who underwent laparotomy for NEC. METHODS: We retrospectively reviewed the medical records of 35 ELBWI who underwent laparotomy for NEC from January 2001 to December 2008 at Samsung Medical Center. RESULTS: Of 480 ELBWI, 35 required laparotomy for NEC; the mortality rate was 20% (Alive group n=28, Dead group n=7). The values of preoperative score for neonatal acute physiology-II (P=0.022) and fraction of inspired oxygen (P<0.001) were significantly higher in the dead group and values of base excess (P=0.004) were significantly lower in the dead group. Values of preoperative heart rate, respiration rate, mean blood pressure, pH, CO2, and potassium ion were not significantly different between the study groups. Intraoperative fluid volume was significantly higher in the alive group than in the dead group (P=0.045). Postoperative infusion rate was significantly lower in the alive group than in the dead group (P=0.022). CONCLUSION: Good preoperative condition, more intraoperative fluid infusion, and stable postoperative hemodynamic condition were factors associated with favorable prognosis of laparotomy for NEC in ELBWI.
Blood Pressure ; Enterocolitis, Necrotizing ; Heart Rate ; Hemodynamics ; Humans ; Hydrogen-Ion Concentration ; Incidence ; Infant ; Infant, Low Birth Weight ; Infant, Newborn ; Laparotomy ; Medical Records ; Oxygen ; Potassium ; Prognosis ; Respiratory Rate ; Retrospective Studies