Consistent scaling of whole-shoot respiration between Moso bamboo (Phyllostachys pubescens) and trees

Both Moso bamboo (Phyllostachys pubescens) and tree forests have a large biomass; they are considered to play an important role in ecosystem carbon budgets. The scaling relationship between individual whole-shoot (i.e., aboveground parts) respiration and whole-shoot mass provides a clue for comparing the carbon budgets of Moso bamboo and tree forests. However, nobody has empirically demonstrated whether there is a difference between these forest types in the whole-shoot scaling relationship. We developed whole-shoot chambers and measured the shoot respiration of 58 individual mature bamboo shoots from the smallest to the largest in a Moso bamboo forest, and then compared them with that of 254 tree shoots previously measured. For 30 bamboo shoots, we measured the respiration rate of leaves, branches, and culms. We found that the scaling exponent of whole-shoot respiration of bamboo fitted by a simple power function on a log–log scale was 0.843 (95 % CI 0.797–0.885), which was consistent with that of trees, 0.826 (95 % CI 0.799–0.851), but higher than 3/4, the value typifying the Kleiber’s rule. The respiration rates of leaves, branches, and culms at the whole-shoot level were proportional to their mass, revealing a constant mean mass-specific respiration of 1.19, 0.224, and 0.0978 µmol CO2 kg- 1 s- 1, respectively. These constant values suggest common traits of organs among physiologically integrated ramets within a genet. Additionally, the larger the shoots, the smaller the allocation of organ mass to the metabolically active leaves, and the larger the allocation to the metabolically inactive culms. Therefore, these shifts in shoot-mass partitioning to leaves and culms caused a negative metabolic scaling of Moso bamboo shoots. The observed convergent metabolic scaling of Moso bamboo and trees may facilitate comparisons of the ecosystem carbon budgets of Moso bamboo and tree forests. © 2021, The Author(s)

Ontogenetic changes in root and shoot respiration, fresh mass, and surface area of Fagus crenata

BACKGROUND AND AIMS: To date, studies on terrestrial plant ecology and evolution have primarily focused on the trade-off patterns in the allocation of metabolic production to roots and shoots in individual plants and the scaling of whole-plant respiration. However, few empirical studies have investigated the root:shoot ratio by considering scaling whole-plant respiration at various sizes throughout ontogeny. METHODS: Here, using a whole-plant chamber system, we measured the respiration rates, fresh mass, and surface area of entire roots and shoots from 377 Fagus crenata individuals, from germinating seeds to mature trees, collected from five different Japanese provenances. Nonlinear regression analysis was performed for scaling of root and shoot respiration, fresh mass, and surface area with body size. KEY RESULTS: Whole-plant respiration increased rapidly in germinating seeds. In the seedling to mature tree size range, the scaling of whole-plant respiration to whole-plant fresh mass was expressed as a linear trend on the log-log coordinates (exponent slightly larger than 0.75). In the same body size range, root and shoot respiration versus whole-plant fresh mass were modelled by upward convex (exponent decreased from 2.35 to 0.638) and downward convex trends (exponent increased from -0.918 to 0.864), respectively. The root fraction in the whole-plant respiration, fresh mass, and surface area continuously shifted throughout ontogeny, increasing in smaller seedlings during early growth stages and decreasing in larger trees. CONCLUSIONS: Our results suggest a gradual shift in allocation priorities of metabolic energy from root in seedlings to shoot in mature trees, providing insights into how roots contribute to shoot and whole-plant growth during ontogeny. The models of root:shoot ratio in relation to whole-plant physiology could be applied in tree growth modelling, and in linking the different levels of ecological phenomena, from individuals to ecosystems.Publishe

Reduced-port surgery for rectal cancer

Laparoscopic surgery for rectal cancer has short-term and long-term oncological outcomes similar to those of open surgery. Conventional multiport laparoscopic surgery (CMLS) for rectal cancer requires four or five abdominal incisions for trocars, each of which could lead to complications and/or pain. Single-incision laparoscopic surgery (SILS) would reduce the incidence of such wound-related complications and achieve better cosmetic outcomes relative to CMLS. The potential advantages of SILS are less pain and more rapid recovery than achieved with CMLS. However, SILS is rarely used for rectal cancer because of the high-level technical expertise required. Reduced-port laparoscopic surgery (RPS), which involves one additional port, may bridge the technical gap between CMLS and SILS and has a less steep learning curve. RPS for rectal cancer has a short history, and its usefulness has not yet been fully established. Here, we review the present situation, challenges, and future prospects for RPS for rectal cancer

Expression of Epidermal Growth Factor Receptor Detected by Cetuximab Indicates Its Efficacy to Inhibit In Vitro and In Vivo Proliferation of Colorectal Cancer Cells.

Cetuximab is a chimeric mouse-human monoclonal antibody that targets the human epidermal growth factor receptor (EGFR). However, EGFR expression determined by immunohistochemistry does not predict clinical outcomes of colorectal cancer (CRC) patients treated with cetuximab. Therefore, we evaluated the correlation between EGFR levels detected by cetuximab and drug sensitivities of CRC cell lines (Caco-2, WiDR, SW480, and HCT116) and the A431 epidermoid carcinoma cell line. We used flow cytometry (FCM) to detect EGFR-binding of biotinylated cetuximab on the cell surface. Subcloned cell lines showing the highest and lowest EGFR expression levels were chosen for further study. Cytotoxic assays were used to determine differential responses to cetuximab. Xenograft models treated with cetuximab intraperitoneally to assess sensitivity to cetuximab. Strong responses to cetuximab were specifically exhibited by subcloned cells with high EGFR expression levels. Furthermore, cetuximab inhibited the growth of tumors in xenograft models with high or low EGFR expression levels by 35% and 10%-20%, respectively. We conclude that detection of EGFR expression by cetuximab promises to provide a novel, sensitive, and specific method for predicting the sensitivity of CRC to cetuximab

Needlescopic versus conventional laparoscopic surgery for colorectal cancer ~a comparative study~

Objectives: This study set out to determine whether Needlescopic surgery (NS) produces comparable surgical outcomes for patients with colorectal cancer (CRC) compared to conventional multi-port laparoscopic surgery (MPS). Methods: We used the five-port method with a 3.5 cm umbilical incision for extraction and reconstruction during MPS for CRC. One or two 5 mm ports were exchanged for needle forceps and all surgical procedures were as for previous MPS since July 2012. We investigated the short-term outcomes of 138 consecutive patients who underwent curative resection of CRC by NS (July 2012-August 2014) and 130 consecutive patients with CRC treated with MPS during a previous period (January 2010-June 2012). Results: Operative time in the NS group was comparable to that of MPS (p=0.467); the NS group had significantly less estimated blood loss (p=0.002) and a shorter postoperative hospital stay (p<0.001). The mean number of dissected lymph nodes was 27 in both groups (p=0.730). No mortality occurred in either group, and similar morbidity rates were observed (p=0.454). Conclusions: NS using Endo Relief needle forceps is a safe and feasible option compared to conventional MPS for CRC