Patterns of δ15N in forest soils and tree foliage and rings between climate zones in relation to atmospheric nitrogen deposition: A review.

The stable nitrogen (N) isotope ratio (δ15N) of forest samples (soils, tree foliage, and tree rings) has been used as a powerful indicator to explore the responses of forest N cycling to atmospheric N deposition. This review investigated the patterns of δ15N in forest samples between climate zones in relation to N deposition. Forest samples exhibited distinctive δ15N patterns between climate zones due to differences in site conditions (i.e., N availability and retention capacity) and the atmospheric N deposition characteristics (i.e., N deposition rate, N species, and δ15N of deposited N). For example, the δ15N of soil and foliage was higher for tropical forests than for other forests by >1.2 ‰ and 4 ‰, respectively due to the site conditions favoring N losses coupled with relatively low N deposition for tropical forests. This was further supported by the unchanged or increased δ15N of tree rings in tropical forests, which contrasts with other climate zones that exhibited a decreased wood δ15N since the 1920s. Subtropical forests under a high deposition of reduced N (NHy) had a lower δ15N by 2-5 ‰ in the organic layer compared with the other forests, reflecting high retention of 15N-depleted NHy deposition. At severely polluted sites in East Asia, the decreased δ15N in wood also reflected the consistent deposition of 15N-depleted NHy. Though our data analysis represents only a subset of global forest sites where atmospheric N deposition is of interest, the results suggest that the direction and magnitude of the changes in the δ15N of forest samples are related to both atmospheric N and site conditions particularly for tropical vs. subtropical forests. Site-specific information on the atmospheric N deposition characteristics would allow more accurate assessment of the variations in the δ15N of forest samples in relation to N deposition.

Laparoscopic sacrocolpopexy versus open abdominal sacrocolpopexy for pelvic organ prolapse repair: A retrospective cohort study.

Introduction: Pelvic organ prolapse (POP) is a progressive herniation of the pelvic organs through the urogenital diaphragm and commonly leads to vaginal bulge. Sacrocolpopexy is a procedure that surgically corrects POP and can be performed as open abdominal surgery or laparoscopic surgery. This study was performed to compare the therapeutic efficacies of laparoscopic and abdominal sacrocolpopexy with hysterectomy. Methods: The medical records of 105 patients who had undergone laparoscopic or open abdominal sacrocolpopexy with hysterectomy at Jeju National University Hospital were retrospectively reviewed. We compared the basic characteristics and clinical outcomes of these two groups of patients. Results: No significant difference was observed between the characteristics of the patients in the abdominal-approach group and the laparoscopic-approach group. The laparoscopic-approach group had a lower intraoperative estimated blood loss (177.8 vs. 89.3 mL, P < 0.001) and a shorter operative time (132.0 vs. 112.3 min, P < 0.001) than the abdominal-approach group. The complication rates of the two groups were not significantly different. Conclusion: The results of our study favor the use of a laparoscopic approach for sacrocolpopexy with hysterectomy. The less invasive method leads to less blood loss and a shorter operative time than an open approach, while maintaining a comparable rate of complications.

Case of suspected torsion and amputation of myoma during pregnancy.

INTRODUCTION: Uterine myoma occurs in 1.6-2% of pregnancies. Most myomas during pregnancy are asymptomatic, but 10-20% may develop complications. The most common complication is abdominal pain, usually caused myoma degeneration or torsion of a pedunculated myoma. CASE PRESENTATION: A 40-year-old pregnant woman was transferred with severe left upper abdominal pain with suspicion of left ovarian torsion at 32 weeks of gestation. Magnetic resonance imaging (MRI) demonstrated a 9.8 cm-sized oval mass abutting the uterine fundus, suggesting subserosal myoma with degeneration. She was admitted for pain control, and the pain was relieved in a few days with conservative management. Two years later, she revisited our hospital for the treatment. Total laparoscopic hysterectomy with bilateral salpingectomy was performed. A 6-cm isolated solid mass adhering to the omentum in the pelvic cavity was observed intraoperatively. The trace on the anterior wall of the uterus was considered to be a broken pedicle that had initially connected the mass. CLINICAL DISCUSSION: In our case, the patient had severe abdominal pain, and ultrasound and MRI findings suggested subserosal myoma degeneration. A retrospective diagnosis of torsion was made following the surgery, which was assumed to cause the pain during pregnancy, and that an amputation occurred during or after the pregnancy. CONCLUSION: Diagnosis is based on clinical manifestations and radiologic examination, however, it is usually difficult to diagnose preoperatively, especially among pregnant women who have diagnostic test limitations. Therefore, if a pregnant woman with a myoma complains of abdominal pain, various possibilities should be considered.