Flow generation by the corona ciliata in Chaetognatha - quantification and implications for current functional hypotheses.

The corona ciliata of Chaetognatha (arrow worms) is a circular or elliptical groove lined by a rim from which multiple lines of cilia emanate, located dorsally on the head and/or trunk. Mechanoreception, chemosensation, excretion, respiration, and support of reproduction have been suggested to be its main functions. Here we provide the first experimental evidence that the cilia produce significant water flow, and the first visualisation and quantification of this flow. In Spadella cephaloptera, water is accelerated toward the corona ciliata from dorsal and anterior of the body in a funnel-shaped pattern, and expelled laterally and caudally from the corona, with part of the water being recirculated. Maximal flow speeds were approximately 140µms-1 in adult specimens. Volumetric flow rate was Q=0.0026µls-1. The funnel-shaped directional flow can possibly enable directional chemosensation. The flow measurements demonstrate that the corona ciliata is well suited as a multifunctional organ.

Effect of a 0.5% dilution of propofol on pain on injection during induction of anesthesia in children.

BACKGROUND: Pain on injection of propofol in children has been reported to be as high as 30-80%. The reason for the pain is assumed to be the aqueous phase of the propofol emulsion. Therefore, for the first time, this study tested the hypothesis that dilution of propofol to a 0.5% emulsion might reduce the incidence of pain during propofol injection. METHODS: The study design was prospective, monocenter, double-blind, and randomized. Sixty-four children aged 2-6 yr were scheduled to receive 0.5% or 1.0% propofol in a medium-chain-triglyceride/long-chain-triglyceride emulsion. Incidence and intensity of pain were assessed by spontaneous expressions of pain and withdrawal of the arm. In a subgroup of 21 children, serum triglyceride levels were measured before and 3 and 20 min after induction. Adverse events were recorded. RESULTS: Amounts of propofol required until loss of eyelash reflex were 4.40+/-1.01 mg/kg for 0.5% propofol and 4.31+/-0.86 mg/kg for 1.0% propofol. Percentages of children who showed at least one pain reaction were 23.3% in the 0.5% propofol group and 70.0% in the 1.0% propofol group (P<0.001). Serum triglycerides were higher in the 0.5% propofol group 3 and 20 min after injection (251.7 vs. 148.8 mg/dl; P=0.001 and 135.5 vs. 75.5 mg/dl; P=0.03). Adverse events or complications did not occur. CONCLUSIONS: Dilution of propofol to a 0.5% medium-chain-triglyceride/long-chain-triglyceride emulsion reduced pain effectively during injection in children aged 2-6 yr. Cumulative doses until 4-5 mg/kg propofol led to moderate increases of triglyceride levels and did not result in significant adverse events.

Prostate lymphoscintigraphy and radio-guided surgery for sentinel lymph node identification in prostate cancer. Technique and results of the first 350 cases.

INTRODUCTION: Having in mind the promising results of lymphoscintigraphy and intraoperative gamma probe application for the detection of sentinel lymph nodes (SLN) in malignant melanoma, breast and penis cancer, we tried to identify the SLN in prostate cancer by applying a comparable technique. MATERIALS AND METHOD: 350 patients with prostate cancer were examined after providing informed consent. The day before pelvic lymphadenectomy technetium-99m nanocolloid was transrectally injected into the prostate under ultrasound guidance. A single central application was done per prostate lobe in most cases. Activity attained 90- 400 MBq, and the total injected volume was about 2-3 ml. Hereafter, lymphoscintigraphy was carried out. Those lymph nodes having been identified as SLN by means of gamma probe detection and lymphoscintigraphy were removed intraoperatively. Later, most of the cases had different types of pelvic lymphadenectomy. SLN received serial sections and immunohistochemistry, non-SLN step sections. RESULTS: 335 patients showed at least 1 SLN in lymphoscintigraphy. 24.7% had lymph node metastases. In 2 patients, metastases in non-SLN were found without at least one SLN being affected (false-negative patient). CONCLUSION: Our experience suggests that the SLN identification is not only feasible in breast cancer and malignant melanoma, but also in prostate cancer with a comparable technique.