Allometry of the quasi-pipe (qPipe) model for estimating tree leaf area and tree leaf mass applied to plant functional types.

The allometry of the pipe model quantifies the approximate proportionality between the tree leaf amount and the stem cross-sectional area at the crown base (ACB). It is useful for estimating and modeling carbon fixation abilities of trees but requires climbing the tree and is thus unsuitable for large-scale studies. Here, we adopted a previously proposed allometry (hereafter the quasi-pipe (qPipe) model allometry) formulating the relationship between the tree leaf amount and a surrogate of ACB, ACB_Est, calculated from tree dimensions measurable from the ground. Using published/unpublished data for 962 trees of 159 species collected between tropical rainforests and boreal forests, we established pipe and qPipe model allometries for evergreen-conifer, deciduous-conifer, evergreen-broadleaf, and deciduous-broadleaf plant functional types (PFTs). For the leaf area per tree (LA), allometric lines on a log-log plane were almost identical among the four PFTs in both models, with slopes of ~ 1. For the leaf mass per tree (LM), however, the allometric lines separated among the four PFTs in both models and had slopes greater than 1, indicating that the proportionality assumed in the pipe model held for LA but not LM. The applicability of the qPipe model in estimating the stand-scale leaf amount was further examined.

A Case of Isolated Cecal Necrosis Preoperatively Diagnosed with Perforation of Cecum.

Isolated cecal necrosis (ICN) is a rare condition which is developed under decreased mesenteric perfusion. Only a few dozen cases of ICN have been reported previously. The patient was a 59-year-old male with a previous history of atrial fibrillation. He presented to our emergency room with the chief complaint of lower abdominal pain. Computed tomography imaging revealed a dilated cecum and presence of free air. With a preoperative diagnosis of perforation of the cecum; an urgent surgery was conducted. Intraoperative findings revealed an ischemic change of the cecum and a laparoscopic-assisted ileocecal resection was performed. The pathological findings showed transmural ischemic change on the anti-mesenteric side of the cecum, and the diagnosis of ICN was achieved. Preoperative diagnosis of ICN is difficult because of its non-specific radiological features. In patients with right lower abdominal pain, ICN should be considered as a differential diagnosis especially if the patient has a comorbidity causing hypotension attack.

Are Preoperative CT Findings Useful for Predicting Postoperative Intraabdominal Abscess in the Patients with Acute Appendicitis?

Background and objective: In patients with acute appendicitis (AA), preoperative computed tomography (CT) findings suggesting development of intraabdominal abscess (IAA) had not been widely used. The aim of this study was to investigate the preoperative clinical and radiological factors that predict the development of a postoperative IAA in patients with AA who were treated by laparoscopic appendectomy (LA). Methods: Two hundred and sixteen patients with pathologically proven AA underwent LA between January 2013 and March 2018 in our department. Medical records and preoperative CT images of these 216 patients were retrospectively reviewed and the predictive factors of postoperative IAA were investigated. In addition, patients were divided into complicated appendicitis (CA) and simple appendicitis (SA) and perioperative factors of two groups were compared. Results: One hundred and forty-seven patients were diagnosed with CA, while the other 69 patients were diagnosed with SA. Sixteen patients developed postoperative IAA in the CA group, while no patients in the SA group did. The univariate analysis revealed that time from onset to surgery more than 3 days (p = 0.011), the preoperative CT finding of periappendiceal fluid (p = 0.003), abscess (p < 0.001), and free air (p < 0.001), operation time more than 120 min (p = 0.023) and placement of a drainage tube (p < 0.001) were significantly associated with the development of IAA. Multivariate analysis revealed that the preoperative CT finding of free air was independently associated with the development of IAA (p = 0.007, odds ratio = 5.427, 95% CI: 1.586⁻18.57). Conclusions: IAA developed predominantly in patients with CA. Preoperative CT findings of free air was found to be an independent predictor for the development of IAA. Surgeons should be meticulous in managing the postoperative course of patients with this finding.

Is postponed laparoscopic appendectomy justified for patients with acute appendicitis?

INTRODUCTION: Recent meta-analyses revealed that laparoscopic appendectomy (LA) is a feasible procedure even for patients with complicated appendicitis. More than a few patients with acute appendicitis arrive at the hospital during night shifts and have their operation postponed for various reasons. However, the feasibility and disadvantages of this so-called "postponed laparoscopic appendectomy" (PLA) remain controversial. METHODS: We included 149 patients who underwent LA for acute appendicitis within 48 h of diagnosis between January 2013 and May 2018. Patients were divided into an immediate LA group (patients who underwent LA within 4 h of diagnosis, n = 84) and a PLA group (patients who underwent LA 4-48 h after diagnosis, n = 65). Comparisons were made between these groups. RESULTS: The preoperative characteristics of the patients in the immediate LA and PLA groups were not significantly different. Operative time was significantly longer in the PLA group than in the LA group (92.5 ± 40.8 vs 78.1 ± 29.7 min, P = 0.012). The incidence of postoperative complications (grade II or higher) was significantly greater in the PLA group than in the LA group (32.3% vs 17.8%, P = 0.041). Multivariate analysis revealed that a preoperative CT finding of periappendiceal fluid (P = 0.005, odds ratio = 4.71) and surgery 4-48 h after diagnosis (P = 0.005, odds ratio = 4.425) were independent risk factors of postoperative complications (grade II or higher). CONCLUSIONS: For patients with acute appendicitis, surgeons should perform immediate LA, if that is the patient's preferred surgical treatment, as long as there is no special reason to postpone surgery.

Torsion of Atypical Meckel's Diverticulum Treated by Laparoscopic-Assisted Surgery.

INTRODUCTION: Meckel's diverticulum (MD) is the most common congenital anomaly of the intestine, with an incidence of 2~4%. Of those, only 2% of patients with MD are symptomatic. Torsion of MD is extremely rare, and only a dozen cases have been previously reported. CASE REPORT: The patient was a 49-year-old male who presented to our emergency room with a chief complaint of lower abdominal pain. Computed tomography imaging revealed an irregular polycystic mass connected to the small intestine that measured 7.5 cm in a diameter. A laparoscopic-assisted partial resection of the jejunum was performed. The lesion was found to have caused torsion and was located 130 cm from the ileocecal valve. The specimen was polycystic in appearance and showed communicating links with the submucosal layer of jejunum but not with the lumen. The pathological diagnosis was a torsion of an atypical presentation of MD. CONCLUSION: This case was different from typical cases of MD in that it was located on significantly oral side and had the appearance of polycystic morphology.

Ileo-ileal intussusception caused by lymphangioma of the small bowel treated by single-incision laparoscopic-assisted ileal resection.

Intraabdominal lymphangiomas are uncommon; additionally, those affecting the gastrointestinal tract are rare and account for less than 1% of cases. Intussusception caused by a cystic lymphangioma of the small bowel is extremely rare. The patient was a 20-year-old woman who visited our emergency room with a complaint of abdominal pain. A computed tomography image revealed ileo-ileal intussusception with a leading hypovascular mass measuring 1 cm in a diameter. Single-incision laparoscopic-assisted ileal resection was performed. The surgical specimen consisted of a soft polycystic mass. Macroscopically, a pedunculated polyp with a convolutional pattern was found. Microscopically, the inner surfaces of the cysts were covered with a single layer of endothelial cells. On immunohistochemical examination, the endothelial cells were partially positive for D2-40 and CD34. Smooth muscle cells were also found around the cysts. The lesion was diagnosed as a cystic lymphangioma. Dozens of cases of small bowel lymphangiomas have previously been reported. Of these, cases with intussusception were very rare. This is the first case of small bowel intussusception due to lymphangioma treated by single-incision laparoscopic-assisted surgery.

Multiple Gastric Gastrointestinal Stromal Tumors in a Patient with Neurofibromatosis Type 1.

Gastrointestinal stromal tumors (GISTs) are relatively common in neurofibromatosis type 1 (NF 1) patients. Approximately 90% of GISTs associated with NF 1 are located in the small intestine, while sporadic GISTs are most commonly located in the stomach. Here we report an extremely rare case of an NF 1 patient with multiple gastric GITs (90 or more) but without multiple small intestinal tumors. A 63-year-old female patient who had a history of NF 1 underwent surgery for a gastric neuroendocrine tumor and gastric submucosal tumor (SMT). During the operation, multiple small nodules were identified on the serosal surface of the upper stomach. SMT and multiple nodules on the serosal surface were diagnosed as GISTs consisting of spindle cells positive for KIT, CD34, and DOG-1. Both GIST and the normal gastric mucosa showed no mutations not only in the c-kit gene (exons 8, 9, 11, 13, and 17) but also in the PDGFRA gene (exons 12, 14, and 18). This patient is being followed up without the administration of a tyrosine kinase inhibitor.

Eosinophil-associated gastrointestinal disorders with asthma: immunohistochemical analyses.

We report 5 patients with eosinophil-associated gastrointestinal disorders (EGIDs) and asthma. All patients developed EGIDs while asthma remained clinically stable. Asthma severity was moderate persistent and severe persistent and 2 patients had intolerance to nonsteroidal anti-inflammatory drugs. By immunohistochemical analysis of the mucosa, eosinophils, macrophages, and T cells were found to be the major infiltrating cells. There was a lesser degree of infiltration of mast cells and B cells but no neutrophils. Compared with normal controls, increased counts of eosinophils and CD8+ T cells were found in the duodenum, and eosinophils, macrophages, and CD4+ T cells in the colon.

Chronic pyelonephritis presenting as multiple tumor-like renal lesions.

We encountered a 49-year-old Japanese man in whom tumor-like renal lesions developed as a result of chronic Staphylococcus aureus pyelonephritis. The patient complained of general fatigue, weight loss, and anorexia for 6 months. Contrast-enhanced computed tomography (CT) of the abdomen revealed multiple low-density lesions in both kidneys and paraaortic lymphadenopathy. A strong uptake of Ga67 citrate in the lesions and elevation of serum soluble interleukin-2 receptor and thymidine kinase activity were strongly suggestive of primary renal lymphoma; however, histologic examination of renal biopsy specimens revealed severe tubulointerstitial change, consistent with chronic pyelonephritis. Following systemic antibiotic treatment, multiple tumor-like lesions regressed 4 months later. This case suggested that chronic pyelonephritis could present as bilateral renal tumors.

Long-term survival after report resection of pulmonary metastases from hepatocellular carcinoma: report of two cases.

Hepatocellular carcinoma (HCC) is often treated most effectively by resection. Although improved surgical procedures and perioperative care have made hepatic resection safe, the prognosis of patients with HCC is still poor because of the high incidence of postoperative recurrence. The most common site of extrahepatic recurrence is the lung. However, because of its multiplicity and concurrent recurrence in the liver remnant, resection of pulmonary metastases form HCC is rarely beneficial. We report two cases of long-term survival after repeated pulmonary resection of metastasis from HCC. At the time of this report the two patients were free of disease, 110 months and 107 months, respectively, after their initial hepatectomy. These case reports show that pulmonary metastases from HCC can be successfully resected in selected patients.

Spatial arrangement of branches in relation to slope and neighbourhood competition.

To gain a better understanding of the effects of spatial structure on patterns of neighbourhood competition among hardwood trees, the three-dimensional extension of primary branches was surveyed for ten community-grown Castanea crenata (Fagaceae) trees with respect to the positioning of neighbouring branches and the slope of the forest floor. There were significantly more branches extending towards the lower side of the slope than towards the upper side, but structural properties such as branch length and vertical angle were not affected by slope. When horizontal extension of a branch towards its neighbour was compared for a C. crenata branch and a neighbouring heterospecific, the former was significantly narrower than the latter when the inter-branch distance (horizontal distance between the base positions of two neighbouring branches) was short (< approx. 5 m). Castanea crenata branches tended to extend in a direction avoiding neighbouring branches of heterospecifics when the inter-branch distance was short. Furthermore, for an inter-branch distance <3 m, the horizontal extension of a C. crenata branch was less when it was neighbouring a heterospecific branch than when neighbouring a conspecific branch. These results suggest that horizontal extension of C. crenata branches is more prone to spatial invasion by nearby neighbouring branches of heterospecifics, and that the invasion can be lessened when C. crenata trees are spatially aggregated. The reason why such an arrangement occurs is discussed in relation to the later leaf-flush of C. crenata compared with that of other species in the forest.