Significant neonatal intraoperative cerebral and renal oxygen desaturation identified with near-infrared spectroscopy.

INTRODUCTION: Near-infrared spectroscopy (NIRS) was used to monitor intraoperative regional oxygen saturation (rSO2) during open (Op) and minimally invasive (MI) surgery performed in neonates (N) and children. MATERIALS AND METHODS: NIRS sensors were applied to the forehead and flanks for cerebral rSO2 (C-rSO2) and renal rSO2 (R-rSO2), respectively. MI included laparoscopy (La), retroperitoneoscopy (Re) and thoracoscopy (Th). In children, Op and MI were major operations taking at least 3 h (MOp; MMI). Pathological desaturation (PD) was defined as > 20% deterioration in rSO2. RESULTS: Mean ages at surgery were N: 5.2 ± 8.2 days, MOp: 2.4 ± 2.9 years, and MMI: 3.8 ± 4.3 years. Despite significantly shorter operative times in N (169 ± 94 min; p < 0.0001), PD was significantly worse; PD(C-rSO2): N = 14/35 (40.0%) versus MOp = 3/36 (8.3%) and MMI = 7/58 (12.1%); p = 0.0006, and PD(R-rSO2): N = 27/35 (77.1%) versus MOp = 6/36 (16.7%) and MMI = 7/58 (12.1%); p < 0.0001, respectively. PD(R-rSO2) occurred immediately with visceral reduction in NOp (Fig. 1) and PD was frequent during NMI(Th) (Fig. 2). rSO2 was stable throughout MOp and MMI (Fig. 3). Fig. 1 Pathological desaturation in renal rSO2 after visceral reduction for gastroschisis. Renal rSO2 deteriorated immediately after viscera were returned to the abdominal cavity rSO2 regional oxygen saturation Fig. 2 Fragility of tissue perfusion during thoracoscopic lung lobectomy in a neonate. Pathological desaturation occurred frequently during neonatal thoracoscopic surgery rSO2 regional oxygen saturation Fig. 3 Changes in cerebral and renal rSO2 according to operative time. Cerebral and renal rSO2 did not appear to change according to operative time during major open and major minimally invasive surgery in children. rSO2 regional oxygen saturation CONCLUSIONS: NIRS is a non-invasive technique for monitoring rSO2 as an indicator of intraoperative stress and vascular perfusion. PD was so significant in neonates that intraoperative NIRS is highly recommended during thoracoscopy and procedures requiring visceral manipulation.

Expression of Genes Involved in Offensive and Defensive Phenotype Induction in the Pituitary Gland of the Hokkaido Salamander (Hynobius retardatus).

Amphibians exhibit phenotypic plasticity, which allows flexible adaptation to fluctuating environments. Although genes involved in expression of plastic phenotypes have been identified, the endocrine bases of plastic responses are largely unknown. Larvae of the Hokkaido salamander (Hynobius retardatus) plastically display distinct phenotypes, an "offensive phenotype" characterized as larger body with broadened gape and a "defensive phenotype" characterized as enlarged gills and tail and less active behavior, in the presence of prey larval amphibians and predatory larval dragonfly, respectively. In the presence of both prey and predators, the degree of induction of both phenotypes is reduced, suggesting cross-talk between the molecular signaling pathways of these phenotypes. We conducted a transcriptomic analysis to examine how endocrine regulation affects the phenotypic expression by focusing on the pituitary gland. We found that five endocrine genes, i.e., calcitonin related polypeptide alpha (CALCA), growth hormone (GH), neuropeptide B (NPB), parathyroid hormone 2 (PTH2), and prolactin 1 (PRL1), were involved in the expression of both phenotypes. However, we conducted only RNA-seq analysis, and no confirmation of significant up-regulation or down-regulation has been conducted. These results suggest that these genes were up-regulated for induction of the offensive phenotype and down-regulated for induction of the defensive phenotype. Phylogenetic analysis indicated that possible gene duplications of PRL and CALCA have occurred during amphibian evolution. Based on these findings, it is suggested that a trade-off of molecular signaling pathways exists between the two distinct phenotypic expressions. The results also suggest that hormonal-gene duplications might have contributed to the acquisition of phenotypic plasticity in amphibians.

Volatile anesthetic sevoflurane pretreatment alleviates hypoxia-induced potentiation of excitatory inputs to striatal medium spiny neurons of mice.

Sevoflurane, a commonly used anesthetic in surgery, has drawn attention because of its preconditioning effects in hypoxic conditions. To investigate the preconditioning effects in the striatum, a common site for ischemic stroke, we collected whole-cell current-clamp recordings from striatal medium spiny neurons. In our in vitro brain slice experiments, deprivation of oxygen and glucose depolarized the striatal neurons to subthreshold potentials, and the pre-administration of sevoflurane (4%, 15 min) prolonged the time to depolarization. Furthermore, transient hypoxia induced the potentiation of excitatory postsynaptic potentials, which play a part in post-ischemic excitotoxicity. Glibenclamide, a KATP channel inhibitor, reversed the prolonged time to depolarization and the prevention of the pathological potentiation of excitatory responses, indicating that the short exposure to sevoflurane likely participates in neuroprotection against hypoxia via activation of KATP channels. A monocarboxylate transporter blocker, 4-CIN, also depolarized striatal neurons. Interestingly, the blockade of monocarboxylate transporters that supply lactate to neurons caused the pathological potentiation, even in the presence of enough oxygen and glucose. In this case, sevoflurane could not prevent the pathological potentiation, suggesting the involvement of monocarboxylate transporters in the sevoflurane-mediated effects. These results indicate that sevoflurane protects striatal neurons from hypoxic damage and alleviates the pathological potentiation. Under these conditions, sevoflurane may become an effective intervention for patients undergoing surgery.

Pulmonary lobectomy techniques in infants and children.

Thoracoscopic pulmonary lobectomy (TPL) techniques in infants and children are presented practically with concise descriptions and numerous illustrations. TPL is the treatment of choice for congenital pulmonary airway malformation and intralobar pulmonary sequestration, both now commonly diagnosed prenatally. Timing of surgery is somewhat controversial in asymptomatic cases with small isolated lesions. Incomplete fissures and history of chest infections are most problematic. Thorough understanding of anatomic relations preoperatively is vital for successful outcome and thin-slice computed tomography with 3D reconstruction of vessels is valuable. Judicious placement of trocars and switching instruments between trocars improves visualization and safety. Specific techniques for all commonly performed TPL are included.

Gene expression profiles in Rana pirica tadpoles following exposure to a predation threat.

BACKGROUND: Rana pirica tadpoles show morphological changes in response to a predation threat: larvae of the dragonfly Aeshna nigroflava induce heightened tail depth, whereas larval salamander Hynobius retardatus induce a bulgy morphology with heightened tail depth. Although both predators induce similar tail morphologies, it is possible that there are functional differences between these tail morphs. RESULTS: Here, we performed a discriminant microarray analysis using Xenopus laevis genome arrays to compare tail tissues of control and predator-exposed tadpoles. We identified 9 genes showing large-scale changes in their expression profile: ELAV-like1, methyltransferase like 7A, dolichyl-phosphate mannosyltransferase, laminin subunit beta-1, gremlin 1, BCL6 corepressor-like 1, and three genes of unknown identity. A further 80 genes showed greater than 5 fold differences in expression after exposure to dragonfly larvae and 81 genes showed altered expression after exposure to larval salamanders. Predation-threat responsive genes were identified by selecting genes that reverted to control levels of expression following removal of the predator. Thirteen genes were induced specifically by dragonfly larvae, nine others were salamander-specific, and sixteen were induced by both. Functional analyses indicated that some of the genes induced by dragonfly larvae caused an increase in laminins necessary for cell adhesion in the extracellular matrix. The higher expression of gremlin 1 and HIF1a genes after exposure to dragonfly larvae indicated an in vivo hypoxic reaction, while down-regulation of syndecan-2 may indicate impairment of angiogenesis. Exposure to larval salamanders caused down-regulation of XCIRP-1, which is known to inhibit expression of adhesion molecules; the tadpoles showed reduced expression of cα(E)-catenin, small muscle protein, dystrophin, and myosin light chain genes. CONCLUSION: The connective tissue of tadpoles exposed to larval salamanders may be looser. The differences in gene expression profiles induced by the two predators suggest that there are functional differences between the altered tail tissues of the two groups of tadpoles.

Transcriptome analysis of predator- and prey-induced phenotypic plasticity in the Hokkaido salamander (Hynobius retardatus).

Predator- and prey-induced phenotypic plasticity is widely observed among amphibian species. Although ecological factors inducing diverse phenotypic responses have been extensively characterized, we know little about the molecular bases of variation in phenotypic plasticity. Larvae of the Hokkaido salamander, Hynobius retardatus, exhibit two distinct morphs: the presence of their prey, Rana pirica tadpoles, induces a broad-headed attack morph, and the presence of predatory dragonfly nymphs (Aeshna nigroflava) induces a defence morph with enlarged external gills and a high tail. To compare the genes involved in predator- and prey-induced phenotypic plasticity, we carried out a de novo transcriptome analysis of Hokkaido salamander larvae exposed to either prey or predator individuals. First, we found that the number of genes involved in the expression of the defence morph was approximately five times the number involved in the expression of the attack morph. This result is consistent with the fact that the predator-induced plasticity involves more drastic morphological changes than the prey-induced plasticity. Second, we found that particular sets of genes were upregulated during the induction of both the attack and defence morphs, but others were specific to the expression of one or the other morph. Because both shared and unique molecular mechanisms were used in the expression of each morph, the evolution of a new plastic phenotype might involve both the co-option of pre-existing molecular mechanisms and the acquisition of novel regulatory mechanisms.

Safety of surgery for neonatal congenital diaphragmatic hernia as reflected by arterial blood gas monitoring: thoracoscopic versus open repair.

PURPOSE: We monitored arterial blood gases during thoracoscopic (TR) and open repair (OR) of congenital diaphragmatic hernia (CDH) to assess the safety of intraoperative hypercapnia and acidosis. METHODS: We reviewed 30 neonatal CDH cases (OR = 10, TR = 20) diagnosed prenatally or within 6 h of birth at out institution from 2002 to 2014 not requiring inhaled nitric oxide (NO) intraoperatively. OR, routine until 2006 was replaced by TR in 2007. All subjects were managed identically. RESULTS: Five TR cases requiring conversion to OR were excluded. Prenatal diagnosis, gestational age at birth, gender, birth weight, and side of CDH were similar. Preoperative PaCO2 and pH were not significantly different. However, while intraoperative increase in mean PaCO2 (38.8-62.8 mmHg; p < 0.01) and decrease in mean pH (7.44-7.25; p < 0.01) were significant in TR, intraoperative PaCO2 was <70 mmHg in 12/15 cases and intraoperative pH was >7.20 in 11/15 cases. Both PaCO2 and pH reverted to normal on completion of surgery; pre- and postoperative results were comparable. There were no postoperative complications. CONCLUSIONS: It would appear that neonatal cases of CDH not requiring NO can tolerate TR, despite transient reversible deterioration in acid/base balance, indicating that TR is safe for the treatment of selected cases of CDH.

Effects of the volatile anesthetic sevoflurane on tonic GABA currents in the mouse striatum during postnatal development.

The volatile anesthetic sevoflurane, which is widely used in pediatric surgery, has proposed effects on GABAA receptor-mediated extrasynaptic tonic inhibition. In the developing striatum, medium-sized spiny projection neurons have tonic GABA currents, which function in the excitatory/inhibitory balance and maturation of striatal neural circuits. In this study, we examined the effects of sevoflurane on the tonic GABA currents of medium spiny neurons in developing striatal slices. Sevoflurane strongly increased GABAA receptor-mediated tonic conductance at postnatal days 3-35. The antagonist of the GABA transporter-1, 1-[2-[[(diphenylmethylene)imino]oxy]ethyl]-1,2,5,6-tetrahydro-3-pyridinecarboxylic acid hydrochloride further increased tonic GABA conductance during the application of sevoflurane, thereby increasing the total magnitude of tonic currents. Both GABA (5 µM) and 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridine-3-ol hydrochloride, the δ-subunit-containing GABAA receptor agonist, induced tonic GABA currents in medium spiny neurons but not in cholinergic neurons. However, sevoflurane additively potentiated the tonic GABA currents in both cells. Interestingly, 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridine-3-ol hydrochloride-sensitive neurons made a large current response to sevoflurane, indicating the contribution of the δ-subunit on sevoflurane-enhanced tonic GABA currents. Our findings suggest that sevoflurane can affect the tone of tonic GABA inhibition in a developing striatal neural network.

Comparison of the value of tissue-sealing devices for thoracoscopic pulmonary lobectomy in small children: a first report.

Accurate division and sealing of lung parenchyma particularly in cases of total or near total incomplete fissure are crucial for preventing air leakage following thoracoscopic pulmonary lobectomy (TPL). However, conventional endoscopic stapling devices cannot be used during TPL in small children because of limited space. Consequently, Ligasure (LS) and Enseal (ES) devices are being used instead. We are the first to compare LS and ES for efficacy and efficiency during TPL. Of 26 TPL (6 upper, 3 middle, and 17 lower) performed for congenital adenomatoid malformation (n = 16) and sequestration (n = 10), incomplete fissure was found in 14. TPL (LS = 11; ES = 15) was performed conventionally in the lateral decubitus position with single lung ventilation using four 5 mm trocars. All cases had a chest tube inserted intraoperatively that was left in situ. Patient demographics, location of pathology, incidence of incomplete fissure, mean age/weight at TPL, mean blood loss, and mean operative time were all similar. However, duration of chest tube insertion was significantly shorter in ES because there was less postoperative air leakage (1.3 vs. 3.9 days; p < 0.05). ES would appear to seal lung parenchyma more effectively during TPL based on the shorter duration of chest tube insertion.

Intraoperative Bronchoscopic Inspection Facilitates Thoracoscopic Repair of Esophageal Atresia with Tracheoesophageal Fistula.

Aim: The value of intraoperative bronchoscopic inspection (IBI) for accurate confirmation of the location and distance between the distal tracheoesophageal fistula (TEF) and the proximal blind end of the esophagus (GAP) was evaluated in Type C esophageal atresia (EA)+TEF. Methods: IBI involved inserting the tip of a bronchoscope into the TEF and a nasogastric tube into the blind end of the EA and measuring GAP with fluoroscopy. EA+TEF patients (n = 23) treated thoracoscopically between 2007 and 2020 were classified according to IBI as IBI+ (n = 16) and IBI- (n = 7) to compare demographics, operative time, and time taken for TEF division. Results: Demographics were similar. Mean time for TEF division (15.4 ± 4.6 minutes for IBI+ versus 38.6 ± 20.9 minutes for IBI-; p < .05) and mean operative time (215.3 ± 48.9 minutes for IBI+ versus 286.4 ± 51.7 minutes for IBI+; p < .05) were significantly shorter. Mean GAP measured radiographically was 0.5 cm (range: 0-1.2 cm); mean GAP measured with IBI was 0.9 cm (range: 0-2.2 cm). Postoperative complications were 3 anastomotic leakages (1/16 in IBI+ and 2/7 in IBI-) that resolved without surgery and 8 strictures (3/16 in IBI+ and 5/7 in IBI-) treated by dilatation. Conclusions: IBI was effective for measuring GAP and is recommended for improving the efficiency of thoracoscopic repair.

Imbalanced suppression of excitatory and inhibitory synaptic transmission onto mouse striatal projection neurons during induction of anesthesia with sevoflurane in vitro.

Suppression of movement during induction of anesthesia is mediated through subcortical structures. We studied the effects of a brief, 5-min application of a clinically relevant concentration of sevoflurane (two minimum alveolar concentration) on the electrophysiological activities of the medium spiny neurons (MSNs) of the striatum in brain slice preparations, using a whole-cell patch-clamp technique. We found that sevoflurane slightly depolarized principal neurons in the cortex and the striatum without a significant alteration in spike threshold. Furthermore, it depressed the peak, as well as the net, charge transfer of intrastriatally evoked inhibitory postsynaptic currents (eIPSCs) much more strongly than those of excitatory postsynaptic currents (EPSCs), and this inhibition was accompanied by an elevated paired-pulse ratio. The strong suppression of eIPSCs paralleled a significant suppression of the frequency, but not the amplitude, of miniature IPSCs (mIPSCs), and was associated with a transient increase in the frequency of spontaneous EPSCs. Treatment with the Ca(2+) channel blocker Cd(2+) restored the frequency of mIPSCs to the control level, indicating sevoflurane's strong presynaptic suppression of γ-aminobutyric acid release in the striatum. In contrast, in hippocampal CA1 pyramidal neurons sevoflurane produced an enhancement of the net charge transfer of IPSCs, while it suppressed EPSCs to an equivalent degree to that in striatal MSNs. These results suggest that, in contrast to its effects on other brain structures, sevoflurane shifts the balance between synaptic excitation and inhibition in the direction of excitation in the striatum, thereby causing involuntary movements during induction of anesthesia by sevoflurane.

Pulmonary artery size as an indication for thoracoscopic repair of congenital diaphragmatic hernia in neonates.

PURPOSE: We reviewed 24 consecutive cases of prenatally or immediately postnatally diagnosed left-sided congenital diaphragmatic hernia (CDH) to evaluate pulmonary artery (PA) size as an indication for thoracoscopic repair (TR). METHODS: CDH repair is planned once echocardiography confirms improvement in pulmonary hypertension. TR is chosen if cardiopulmonary status is stable more than 10 min in the decubitus position in the neonatal intensive care unit (NICU) under conventional mechanical or high frequency oscillatory ventilation (HFOV) with/without nitric oxide (NO) and the patient appears likely to tolerate manual ventilation during transfer to the operating room. Otherwise open repair (OR) is performed in NICU. Proximal right PA (RPA) and left PA (LPA) diameters measured at birth were assessed with respect to the type of repair. RESULTS: 10/24 had TR and 14/24 had OR. TR cases had significantly larger RPA/LPA diameters (3.52 ± 0.23 vs. 3.10 ± 0.56 mm, p < 0.05 for RPA; 3.04 ± 0.26 vs. 2.48 ± 0.37, p < 0.01 for LPA), and significantly less requirement for HFOV (70 vs. 100 %, p < 0.05) and NO (20 vs. 86 %, p < 0.01). Four TR required conversion to OR for technical reasons (n = 3) and cardiopulmonary instability (n = 1). CONCLUSIONS: TR can be considered when RPA/LPA diameters are larger than 3.0/2.5 mm, respectively, and cardiopulmonary status is stable without NO.

Retroperitoneoscopic Surgery in Children Does Not Cause Pathological Desaturation in Cerebral/Renal Oxygenation on Near-Infrared Spectroscopy Compared with Laparoscopic and Thoracoscopic Surgery.

Introduction: Cerebral and renal regional oxygen saturation (C-rSO2 and R-rSO2, respectively) were monitored using near-infrared spectroscopy in pediatric patients (range: 0.3-14.3 years) during minimally invasive surgery (MIS) taking at least 3 hours performed by laparoscopy (Lap), thoracoscopy (Tho), or retroperitoneoscopy (Ret) from January 2019 to December 2021. Materials and Methods: Criteria compared were operative time, preoperative/intraoperative hemoglobin, blood loss, mean arterial pressure, arterial partial pressure of carbon dioxide (PaCO2), peripheral oxygen saturation (SpO2), C-rSO2, and R-rSO2. Pathological desaturation (PD) was defined as >20% decrease from baseline, and statistical significance as P < .05. Results: Subjects (n = 79) were similar for gender, age, and body mass index. MIS procedures were: Lap = 45, Tho = 20, Ret = 14; one Lap case required conversion for severe adhesions, not PD. Intraoperative PaCO2 (mmHg) was significantly higher in Tho (maximum: 59.5 ± 17.0, minimum: 39.9 ± 7.5) versus Lap (maximum: 39.9 ± 5.1, minimum: 34.6 ± 3.9) and Ret (maximum: 37.8 ± 4.2, minimum: 35.0 ± 3.3); P < .0001 (maximum), P = .0013 (minimum). Minimum intraoperative SpO2 was significantly lower in Tho (P < .0001). Mean operative times were significantly shorter in Tho (259 ± 114 minutes) versus Lap (433 ± 154 minutes) and Ret (342 ± 100 minutes); P < .0001, respectively. PD was absent during Ret (C-rSO2: 0/14 = 0% and R-rSO2: 0/14 = 0%). Differences in PD for Lap (C-rSO2: 7/45 = 15.6% and R-rSO2: 10/45 = 22.2%) and Tho (C-rSO2: 9/20 = 45.0%, and R-rSO2: 7/20 = 35.0%) were significant; P = .0028 for C-rSO2 and P = .0497 for R-rSO2. Hemoglobin and blood loss were similar. Conclusions: PD was absent during Ret, despite longer operative times. If Ret is indicated for a procedure, neurodevelopmental sequelae of MIS could be minimized.

Predation risk suppresses the positive feedback between size structure and cannibalism.

1. Cannibalism can play a prominent role in the structuring and dynamics of ecological communities. Previous studies have emphasized the importance of size structure and density of cannibalistic species in shaping short- and long-term cannibalism dynamics, but our understanding of how predators influence cannibalism dynamics is limited. This is despite widespread evidence that many prey species exhibit behavioural and morphological adaptations in response to predation risk. 2. This study examined how the presence and absence of predation risk from larval dragonflies Aeshna nigroflava affected cannibalism dynamics in its prey larval salamanders Hynobius retardatus. 3. We found that feedback dynamics between size structure and cannibalism depended on whether dragonfly predation risk was present. In the absence of dragonfly risk cues, a positive feedback between salamander size structure and cannibalism through time occurred because most of the replicates in this treatment contained at least one salamander larvae having an enlarged gape (i.e. cannibal). In contrast, this feedback and the emergence of cannibalism were rarely observed in the presence of the dragonfly risk cues. Once salamander size divergence occurred, experimental reversals of the presence or absence of dragonfly risk cues did not alter existing cannibalism dynamics as the experiment progressed. Thus, the effects of risk on the mechanisms driving cannibalism dynamics likely operated during the early developmental period of the salamander larvae. 4. The effects of dragonfly predation risk on behavioural aspects of cannibalistic interactions among hatchlings may prohibit the initiation of dynamics between size structure and cannibalism. Our predation trials clearly showed that encounter rates among hatchlings and biting and ingestion rates of prospective prey by prospective cannibals were significantly lower in the presence vs. absence of dragonfly predation risk even though the size asymmetry between cannibals and victims was similar in both risk treatments. These results suggest that dragonfly risk cues first suppress cannibalism among hatchlings and then prevent size variation from increasing through time. 5. We suggest that the positive feedback dynamics between size structure and cannibalism and their modification by predation risk may also operate in other systems to shape the population dynamics of cannibalistic prey species as well as overall community dynamics.

Indications for thoracoscopic repair of congenital diaphragmatic hernia in neonates.

PURPOSE: We reviewed 26 consecutive cases of congenital diaphragmatic hernia (CDH) prospectively to establish selection criteria for successful thoracoscopic CDH repair (TR). METHODS: Five preoperative deaths were excluded, leaving 21 subjects. TR was only considered once pulmonary hypertension (PH) improved on echocardiography, and if cardiopulmonary status was stable in the decubitus position in the neonatal intensive care unit (NICU) under conventional mechanical or high-frequency oscillatory ventilation (HFOV) with/without nitric oxide (NO) for at least 10 min as a marker for tolerating surgery and manual ventilation was possible for transfer to the operating room. All other patients had open repair (OR). RESULTS: 8/21 had TR and 13/21 had OR. There were significant differences between TR and OR for prenatal diagnosis (37.5 vs. 84.6%, p < 0.05) and earlier surgery (1.4 ± 0.8 vs. 2.5 ± 1.1 days after birth, p < 0.05), respectively. Intraoperative HFOV was required in all OR and 3 TR (p < 0.01). NO was required in 1 TR and 10 OR (p < 0.01). Organ herniation was significantly less in TR (50 vs. 100%, p < 0.01 for stomach; 0 vs. 54%, p < 0.05 for liver). Three TR required conversion to OR because of technical difficulties. One OR died from deteriorating PH. CONCLUSIONS: Our selection criteria for TR would appear to be safe and reasonable.

Congenital Pulmonary Airway Malformation in Children: Advantages of an Additional Trocar in the Lower Thorax for Pulmonary Lobectomy.

Aim: To present the use of an additional trocar (AT) in the lower thorax during thoracoscopic pulmonary lobectomy (TPL) in children with congenital pulmonary airway malformation. Methods: For a lower lobe TPL (LL), an AT is inserted in the 10th intercostal space (IS) in the posterior axillary line after trocars for a 5-mm 30° scope, and the surgeon's left and right hands are inserted conventionally in the 6th, 4th, and 8th IS in the anterior axillary line, respectively. For an upper lobe TPL (UL), the AT is inserted in the 9th IS, and trocars are inserted in the 5th, 3rd, and 7th IS, respectively. By switching between trocars (6th↔8th for the scope, 4th↔6th for the left hand, and 8th↔10th for the right hand during LL and 5th↔7th, 3rd↔5th, and 7th↔9th during UL, respectively), vital anatomic landmarks (pulmonary veins, bronchi, and feeding arteries) can be viewed posteriorly. The value of AT was assessed from blood loss, operative time, duration of chest tube insertion, requirement for post-operative analgesia, and incidence of perioperative complications. Results: On comparing AT+ (n = 28) and AT- (n = 27), mean intraoperative blood loss (5.6 vs. 13.0 ml), operative time (3.9 vs. 5.1 h), and duration of chest tube insertion (2.2 vs. 3.4 days) were significantly decreased with AT (p < 0.05, respectively). Differences in post-operative analgesia were not significant. There were three complications requiring conversion to open/mini-thoracotomy: AT- (n = 2; bleeding), AT+: (n = 1; erroneous stapling). Conclusions: An AT and switching facilitated posterior dissection during TPL in children with congenital pulmonary airway malformation enhancing safety and efficiency.

The benefit of stay sutures during thoracoscopic esophagoesophagostomy in patients with esophageal atresia: a technical report.

We report on technical modifications we developed for thoracoscopic esophagoesophagostomy in patients with esophageal atresia. They are: (1) placing stay sutures along the edges of the atretic esophagi and exteriorizing them through the thoracic wall to expose the luminal surfaces of the esophagi nicely and relieve tension on the anastomosis; (2) leaving 1/5 of the length of the distal and proximal ends of the atretic esophagi intact before placing the stay sutures, to avoid retraction of the mucosa into the lumen; (3) making the diameter of the proximal esophagus 1.5-2 times larger than the diameter of the distal esophagus to make the shape of the anastomosis more streamlined without notching.

Top-down effects on antagonistic inducible defense and offense.

Antagonistic phenotypic plasticity may strongly influence trait evolution in tightly interacting predator-prey pairs as well as the role that trait plasticity plays in community dynamics. Most work on trait plasticity has focused on single predator-prey pairs, but prey must often contend with multiple predators in natural environments. Hence, a better understanding of the evolutionary and ecological significance of phenotypic plasticity requires experiments that examine how multiple predators shape prey trait plasticity. Here, using a simple food chain consisting of a top predator (dragonfly larvae, Aeshna nigroflava), an intermediate predator (salamander larvae, Hynobius retardatus), and frog (Rana pirica) tadpoles as prey, we show that the presence of dragonfly risk cues substantially modifies the intensity of antagonistic morphological plasticity in both amphibians. In the absence of dragonflies, tadpoles produced bulgier bodies in response to salamanders, and salamanders responded to this defense by enlarging their gape size. However, in the presence of dragonfly risk cues, the expression of both antagonistic traits was significantly reduced because tadpoles and salamanders produced phenotypes that are more effective against dragonfly predators. Thus, the reduced antagonism likely emerged, in part, because the benefits of antagonistic trait expression were outweighed by the potential cost of increased vulnerability to dragonfly predation. In addition, our results suggest that when all three species were present, salamander activity levels, which influence the amount of signals required to induce antagonistic traits, were more strongly affected by dragonfly risk cues than were tadpole activity levels. This species-specific difference in activity levels was likely responsible for the reduced tadpole mortality caused by salamanders in the presence vs. absence of dragonfly risk cues. Hence, dragonflies had a positive trait-mediated indirect effect on tadpoles by modifying both the morphological and behavioral traits of salamanders.

Inducible defenses in prey intensify predator cannibalism.

Trophic cascades are often a potent force in ecological communities, but abiotic and biotic heterogeneity can diffuse their influence. For example, inducible defenses in many species create variation in prey edibility, and size-structured interactions, such as cannibalism, can shift predator diets away from heterospecific prey. Although both factors diffuse cascade strength by adding heterogeneity to trophic interactions, the consequences of their interactioh remain poorly understood. We show that inducible defenses in tadpole prey greatly intensify cannibalism in predatory larval salamanders. The likelihood of cannibalism was also strongly influenced by asymmetries in salamander size that appear to be most important in the presence of defended prey. Hence, variation in prey edibility and the size structure of the predator may synergistically affect predator-prey population dynamics by reducing prey mortality and increasing predator mortality via cannibalism. We also suggest that the indirect effects of prey defenses may shape the evolution of predator traits that determine diet breadth and how trophic dynamics unfold in natural systems.

Effects of physical interference on life history shifts in Daphnia pulex.

Daphnia pulex were reared in 50 ml flasks, each containing 1, 20 or 40 individuals, which were serially connected with a 20-mum mesh screens between, in order to examine the effect of physical interference due to crowding on shifts of life history traits throughout two consecutive generations. A flow-through system, designed to maintain a sufficient food supply and minimize the accumulation of metabolites, was used. To eliminate the effect of infochemicals from crowded animals, a single-individual treatment flask was connected to two crowded flasks. In the first generation, D. pulex reared under crowded conditions grew more slowly after day 4 when oogenesis normally starts, and produced less offspring after day 9, compared with an animal reared alone, even when supplied with sufficient food. Although second generation daphniids of each treatment matured faster than in the first generation, crowded females grew more slowly even after day 2 and produced less offspring than single females. Age to maturity was no different between treatments in both generations. Crowded females, therefore, matured to smaller sizes but produced larger neonates compared with single females. Weight-specific reproduction rates of the first clutch were not significantly different between the treatments. These results suggest that physical interference between neighboring individuals due to crowding negatively affects growth and reproduction in daphniids. Crowded daphniids may allocate more energy to reproduction in order to produce larger and more starvation-tolerant offspring in preparation for severe food shortages. Crowding also triggered ephippial egg production and reduced survival compared with the single-individual treatment.