[Advances of pathological diagnosis and molecular pathology of lung neuroendocrine neoplasms]

The pathological classification and diagnostic criteria for lung neuroendocrine neoplasms (NENs) in the 2021 World Health Organization (WHO) lung tumor classification are similar to the prior classifications. However, the advances on the molecular studies of lung NENs have shown that both small cell lung carcinoma and large cell neuroendocrine carcinoma are highly heterogeneous tumors with neuroendocrine characteristics and can be subclassified based on the features of genomics or transcriptomics, which are valuable in the diagnosis of lung NENs subtypes and patient treatment. In addition, it is necessary to interpret emerging concepts such as "lung neuroendocrine tumor G3" and "histological transformation" from pathological perspectives, as well as to know the novel neuroendocrine biomarkers such as INSM1 and POU2F3. This article summarized the diagnostic changes and the advances of molecular pathology of lung NENs based on the latest WHO classification and molecular research.

[Genetic changes and biological potential of proliferative nodule in congenital pigmented nevus]

Objective: To study the genetic changes and biological potential of proliferative nodule in congenital melanocytic nevus. Methods: Whole-exome sequencing was carried out using the technique of next-generation sequencing (NGS) in order to detect the genomic alterations of two cases of proliferative nodules (PN) in congenital melanocytic nevi (CMN). Twelve cases of CMN and ten cases of malignant melanoma were used as benign and malignant controls, respectively. Mutated genes that possessed statistically significant difference between benign and malignant controls were listed, according to what benign and malignant statuses were classified and clustered. The heatmaps of clustering analyses were depicted using heatmap package. Fluorescence in situ hybridization (FISH) was also used to validate the above results. Results: Eighty-six common somatic gene mutations were detected in two samples of PN. Compared with CMN, PN had 52 more mutated genes. Furthermore, 22 of these 52 mutated genes were also detected in malignant melanoma samples. Two cases of PN fell between benign CMN and malignant melanoma in germline mutation clustering. Both cases of PN were positive in the FISH tests. Conclusions: The genetic changes of PN partially overlap with those of CMN and malignant melanoma. Therefore, although most of the PN manifest as a benign lesion clinically, it may have certain malignant potential at the genetic level, and warrant long-term monitoring and follow-up.

Postconditioning Protection Against Myocardiocyte Anoxia/Reoxygenation Injury From Penehyclidine Hydrochloride

Background/Aims

To investigate the postconditioning protective effect of penehyclidine hydrochloride (PHC) against anoxia/reoxygenation (A/R) injury in H9c2 cells along with the involved mechanism and timing effect.

Methods

We divided H9c2 cells into 7 groups: control group, A/R group and PHC+A/R groups at 0 min, 5 mins, 10 mins, 20 mins, 30 mins, respectively (treated with 0.1 μm/L PHC at 0 min, 5 mins, 10 mins, 20 mins, 30 mins after the reoxygenation procedure began). Cell apoptosis, oxidative stress, intracellular Ca²⁺ concentration, mitochondrial membrane potential and mitochondrial permeability transition pore (MPTP) opening were explored. Bcl-2, Bax, Cyt C, caspase-3 and caspase-9 levels were measured.

Results

A/R significantly increased both cell injury and cell apoptosis. PHC showed postconditioning protective effect by attenuating superoxide production, decreasing Ca²⁺ overload, restraining MPTP activities, restoring mitochondrial membrane potential, regulating cell apoptosis proteins and modulation of mitochondrial pathway. Earlier administration of PHC offered greater postconditioning protective effect.

Conclusion

H9c2 cells were protected by PHC from A/R injury regardless of timing of PHC administration (0 min, 5 mins, 10 mins, 20 mins, 30 mins). However, earlier administration of PHC resulted in better PHC postconditioning protection.

[The correlation study of ground glass opacity and lepidic growth pattern component in stage I lung invasive adenocarcinoma]

Objective: To investigate the correlation between Ground Glass Opacity (GGO) component proportion and quantitative classification of lepidic growth pattern in pathological stage Ⅰpulmonary adenocarcinoma. Methods: Pathological and HRCT data of 183 stage Ⅰ invasive adenocarcinoma patients from January 2005 to December 2012 were retrospectively reviewed. The proportion of GGO was calculated from diameter and volume.The correlation between GGO component proportion and lepidic growth pattern in pathological were analyzed by Spearman correlation. Results: Among 183 patients, the proportion of GGO component calculated by maximum diameter method and three-dimensional computerized quantification was 0.43±0.35 and 0.20±0.18, respectively. The percentage of lepidic growth pattern component using semi-quantitative analysis of pathological sections was 0.29±0.25.The proportion of GGO by diameter and three-dimensional computerized quantification was significantly correlated with the percentage of lepidic growth pattern component (r=0.599, P< 0.001; r=0.620, P<0.001). Conclusions: There was a positive correlation between the content of lepidic growth pattern and the content of GGO in the small adenocarcinoma. Three-dimensional computerized quantification was a better method in preoperational evaluation.

[Expression of CD137 in tumor cells of Hodgkin lymphoma from Northern China and its application in pathological differential diagnosis]

目的

明确CD137在北方地区经典型霍奇金淋巴瘤（cHL）中的表达，探讨其作为cHL辅助病理鉴别诊断新指标的可能应用价值。

方法

收集54例cHL患者资料，以55例伴有“HRS样细胞”的非cHL患者为对照。在病理组织标本中选取“HRS细胞”或“HRS样细胞”丰富的区域制作组织芯片；以“HRS细胞”或“HRS样细胞”为观察对象，cHL组应用CD30、CD15、CD20、PAX5、CD3免疫组织化学染色；同时对两组患者标本进行CD137（BBK-2）抗体免疫组织化学染色及采用EBV编码的小RNA（EBER）原位杂交法检测EBV感染状态。

结果

54例cHL患者均为淋巴结内原发，中位年龄45.5（22.0~68.0）岁；男女比例1.7∶1；对照组患者结内54例，结外（皮肤）1例，中位年龄50.0（12.0~81.0）岁；男女比例1.9∶1。54例cHL患者均表达CD30，HRS细胞主要诊断相关免疫标志物CD30、CD15、CD20、CD3阳性表达率依次为100.0%、70.4%、18.5％和0，可见PAX5弱至中等强度表达，阳性率70.4%；EBV感染阳性率25.9%（对照组阳性率21.8%）。cHL组CD137阳性率57.4%，对照组阳性率14.5%，差异有统计学意义（P<0.001）。将cHL组及对照组按照患者年龄（≥60/<60岁）、性别、有无EBV感染、组织学亚型以及主要诊断相关标志物的表达与否进行分组，CD137阳性率差异均无统计学意义（P值均> 0.05）。以2013年为界进行分组，2013年前后两组cHL患者的CD137阳性率差异有统计学意义（39.4%对85.7%，P=0.001），对照组差异无统计学意义（12.5％对16.1%，P=0.705）；2013以后存档的标本中cHL组与对照组患者CD137阳性率差异有统计学意义（85.7％对16.1%，P<0.001）。

结论

通过研究初步证实北方地区大多数cHL患者的HRS细胞表达CD137，而对照组患者“HRS样细胞”CD137阳性率较低。保存期3年以内较保存期3年以上的cHL患者标本CD137阳性率高，更适于进行CD137免疫组织化学染色检测。CD137有望作为辅助cHL病理鉴别诊断的新指标。

Sulfate-reducing bacteria slow intestinal transit in a bismuth-reversible fashion in mice

BACKGROUND

Hydrogen sulfide (H₂ S) serves as a mammalian cell-derived gaseous neurotransmitter. The intestines are exposed to a second source of this gas by sulfate-reducing bacteria (SRB). Bismuth subsalicylate binds H₂ S rendering it insoluble. The aim of this study was to test the hypothesis that SRB may slow intestinal transit in a bismuth-reversible fashion.

METHODS

Eighty mice were randomized to five groups consisting of Live SRB, Killed SRB, SRB+Bismuth, Bismuth, and Saline. Desulfovibrio vulgaris, a common strain of SRB, was administered by gavage at the dose of 1.0 × 10⁹ cells along with rhodamine, a fluorescent dye. Intestinal transit was measured 50 minutes after gavage by euthanizing the animals, removing the small intestine between the pyloric sphincter and the ileocecal valve and visualizing the distribution of rhodamine across the intestine using an imaging system (IVIS, Perkin-Elmer). Intestinal transit (n=50) was compared using geometric center (1=minimal movement, 100=maximal movement). H₂ S concentration (n=30) was also measured when small intestinal luminal content was allowed to generate this gas.

KEY RESULTS

The Live SRB group had slower intestinal transit as represented by a geometric center score of 40.2 ± 5.7 when compared to Saline: 73.6 ± 5.7, Killed SRB: 77.9 ± 6.9, SRB+Bismuth: 81.0 ± 2.0, and Bismuth: 73.3 ± 4.2 (P<.0001). Correspondingly, the Live SRB group had the highest luminal H₂ S concentration of 4181.0 ± 968.0 ppb compared to 0 ± 0 ppb for the SRB+Bismuth group (P<.0001).

CONCLUSIONS & INFERENCES

Live SRB slow intestinal transit in a bismuth-reversible fashion in mice. Our results demonstrate that intestinal transit is slowed by SRB and this effect could be abolished by H₂ S-binding bismuth.

[TNFAIP3 deletion status in classical Hodgkin lymphoma and its relation to Epstein-Barr virus]

Objective: To investigate the TNFAIP3/A20 abnormalities and its association with Epstein-Barr virus (EBV) in classical Hodgkin lymphoma (CHL). Methods: Formalin-fixed, paraffinembedded tissue blocks of 54 CHL patients were collected and subjected to the construction of tissue microarray (TMA) for further analyses. EBV status was evaluated by in situ hybridization (ISH) for EBER1/2 and immunohistochemistry (IHC) with anti-LMP-1 antibody. Fluorescence in situ hybridization (FISH) and IHC were performed to determine the copy number alterations of TNFAIP3 and A20 protein expression respectively. Results: The concordance rate of IHC for LMP-1 and ISH for EBER1/2 was100%, and 25.9% (14/54) cases were identified with EBV infection. Immunohistochemistry analysis demonstrated 27.8% (15/54) cases with A20 expression deficiency. Of the 54 cases tested for A20 expression, 49 cases were simultaneously analyzed by FISH, which showed 10 (20.4% ) cases harboring TNFAIP3 deletion. However, discrepancy was observed between the results of A20 by IHC and TNFAIP3 deletion by FISH. Only 1 case with TNFAIP3 deletion demonstrated complete loss of A20 immunoreactivity. In addition, comparison of the frequency of either A20 expression loss or TNFAIP3 deletion between EBV-positive and-negative cases did not reveal any significance (P>0.05). Conclusion: TNFAIP3 deletion could be observed in both EBV-positive and - negative CHL cases. A20 expression by IHC could not confirm TNFAIP3 deletion by FISH, which might be related to the technical issues.

Role of the NO/cGMP pathway in postoperative vasodilation in perforator flaps

BACKGROUND

The nitric oxide (NO)/cyclic guanylyl monophosphate (cGMP) pathway is one of the most important regulators of tissue perfusion. Here, we sought to elucidate the protective effects of the NO/cGMP pathway on the microcirculation of axial pattern skin flaps.

MATERIAL AND METHODS

Overall 40 rats were divided into four groups (n = 10 each): group A, sildenafil was administered orally at 10 mg/kg daily; group B, sildenafil citrate (10 mg/kg, oral) and nitro-amino-methyl-L-arginine (L-NAME, intraperitoneal injection), a nitric oxide synthase inhibitor, were administered daily; group C, L-NAME was administered alone; and group D, no drugs were administered. After surgery, the surviving flap area was calculated as a percentage of total flap dimensions using the paper template technique. Angiography and imaging were performed to compare the macrovascular changes of the choke zones in the flaps. Histological examinations were performed to compare the differences in microvascular changes between the two choke zones.

RESULTS

A significant improvement of flap survival area and a significant dilation of vessels in both choke zones were found after administration of sildenafil. We also found that the postoperative vasodilation of choke vessels could be altered by inhibition of NO synthase (NOS). Moreover, the vasodilatory effect prolonged by the phosphodiesterase 5 inhibitor sildenafil was attenuated after administration of L-NAME. L-NAME significantly reversed the protection afforded by sildenafil.

CONCLUSIONS

Targeting the NO/cGMP pathway can dilate vessels along the axis of the flap, including the choke vessels, thus augmenting flap viability. Therefore, targeting of this pathway may have therapeutic applications.

Air-assisted intranasal instillation enhances adenoviral delivery to the olfactory epithelium and respiratory tract

Intranasal instillation is used to deliver adenoviral vectors to the olfactory epithelium and respiratory tract. The success of this approach, however, has been tempered by inconsistent infectivity in both the epithelium and lungs. Infection of the epithelium may be hampered in part by the convoluted structure of the cavity, the presence of mucus or poor airflow in the posterior cavity. Delivery of adenovirus to the lungs can be uneven in the various lobes and distal bronchioles may be poorly infected. Current approaches to circumvent these issues rely principally on intubation or intratracheal instillation. Here we describe a technique that significantly improves adenoviral infectivity rates without requiring surgical intervention. We use compressed air to increase circulation of instilled adenovirus, resulting in enhanced infection in both the epithelium and lungs. This procedure is straightforward, simple to perform and requires no specialized equipment. In the epithelium, neurons and sustentacular cells are both labeled. In the lungs, all lobes can be infected, with penetration to the most distal bronchioles. The use of compressed air will likely also be useful for enhancing the distribution of other, desired agents within the epithelium, central nervous system and respiratory tract.

Lead-free KNLNT piezoelectric ceramics for high-frequency ultrasonic transducer application

This paper presents the latest development of a lead-free piezoelectric ceramic and its application to transducers suitable for high-frequency ultrasonic imaging. A lead-free piezoelectric ceramic with formula of (K(0.5)Na(0.5))(0.97)Li(0.03)(Nb(0.9) Ta(0.1))O(3) (abbreviated as KNLNT-0.03/0.10) was fabricated and characterized. The material was found to have a clamped dielectric constant epsilon(33)(S)/epsilon(0)=890, piezoelectric coefficient d(33)=245 pC/N, electromechanical coupling factor k(t)=0.42 and Curie temperature T(c)>300 degrees C. High-frequency (40 MHz) ultrasound transducers were successfully fabricated with the lead-free material. A representative lead-free transducer had a bandwidth of 45%, two-way insertion loss of -18 dB. This performance is comparable to reported performances of popular lead-based transducers. The comparison results suggest that the lead-free piezoelectric material may serve as an alternative to lead-based piezoelectric materials for high-frequency ultrasonic transducer applications.

Lead-free acoustic emission sensors

Acoustic emission (AE) sensors have been fabricated using both soft- and hard-type lead-free (Na0.5K0.5)NbO3-based ceramics. The acoustic and electromechanical properties of the ceramics have been determined using the resonance technique. The lead-free AE sensors were calibrated using a laser source and compared to a commercial sensor. A lead zirconate titanate (PZT) 5H ceramics AE sensor has also been fabricated and calibrated for comparison. It was found that the sensitivity of lead-free AE sensors is comparable to that of the lead-based PZT sensor. To evaluate the sensors for potential application, they have been used in the detection of AE in an impact test. The lead-free sensors can reproduce AE signals accurately without giving artifacts and have potential use in commercial AE systems.

A lead-free piezoelectric transformer in radial vibration modes

In this study, a disk-shaped piezoelectric transformer was fabricated using lead-free (K,Na)NbO(3)-based ceramics with high mechanical quality factor. The transformer can operate in the fundamental or the third radial vibration mode. The transformer is poled along the thickness direction. The top surface is covered by ring/dot silver electrodes separated by an annular gap which serve as the input and output parts of the transformer, respectively. The bottom surface, fully covered with a silver electrode, is grounded as a common electrode. The dimensions of the top ring/dot electrodes are designed such that the third radial vibration mode can be strongly excited. The electrical properties of the transformer with diameter of 34.2 mm and thickness of 1.9 mm were measured. For a temperature rise of 35 degrees C, the transformer has a maximum output power of 12 W. With the matching load, its maximum efficiency is >95%, and maximum voltage gains are 6.5 and 3.9 for the fundamental and the third radial vibration modes, respectively. It has potential to be used in power supply units and other electronic circuits.

Bacterial infection promotes DNA hypermethylation

Maternal oral infection, caused by bacteria such as C. rectus or P. gingivalis, has been implicated as a potential source of placental and fetal infection and inflammatory challenge, which increases the relative risk for pre-term delivery and growth restriction. Intra-uterine growth restriction has also been reported in various animal models infected with oral organisms. Analyzing placental tissues of infected growth-restricted mice, we found down-regulation of the imprinted Igf2 gene. Epigenetic modification of imprinted genes via changes in DNA methylation plays a critical role in fetal growth and development programming. Here, we assessed whether C. rectus infection mediates changes in the murine placenta Igf2 methylation patterns. We found that infection induced hypermethylation in the promoter region-P0 of the Igf2 gene. This novel finding, correlating infection with epigenetic alterations, provides a mechanism linking environmental signals to placental phenotype, with consequences for development.

Stability and release of antiviral drugs from ethylene vinyl acetate (EVA) copolymer

The use of polymer based drug delivery systems in dentistry is a relatively new area of research with the exception of the inhibition of secondary caries by the release of fluoride ions from polyalkenoate cements and their predecessors silicate cements. The present study was to test on orally biocompatible material, ethylene vinyl acetate copolymer (EVA), for release of antiviral drugs at oral therapeutic levels over extended periods of time. We also determined their stability during film casting and release. Materials studied include gancyclovir (GCY), acyclovir (ACY), dichloromethane (DCM), and ethylene vinyl acetate (EVA). The square films (3 x 3 x 0.1 cm) were prepared from the dry sheet obtained by solvent evaporation of polymer casting solutions. These solutions were made of EVA and the drug (40:1) in 70 ml of dichloromethane at 38 degrees C. Then drug release characteristics from the drug loaded films were examined at 37 degrees C for a minimum of 14 days in 10 ml medium (ddwater) replaced daily. Kinetics of drug release were followed by spectral measurements using previously determined lambda(max) values (GCY = 250 nm; ACY = 253 nm). A minimum of three samples was tested and reproducible results were obtained. Drug stability (ACY) during film casting and its release was determined using 1H NMR spectrometer (Bruker DRX-500 and 400). Rate of drug release was determined from the part of the curve (rate vs. time) after the onset of the "burst." Although GCY has a larger molecular weight (255) than ACY (225), GCY exhibited about three times higher rate of release than ACY. This difference in rate values may be explained due to its relatively greater solubility in EVA, facilitating faster diffusion of the molecules through the channels present in EVA. This is consistent with the observation that the rate at which drug molecules diffuse through the channels of the polymer, can be increased by decreasing the molecular weight. In the case of ACY, the molecules may be undergoing molecular associations, perhaps dimerization or trimerization in addition to its lower solubility in EVA. The diffusion of ACY tends to be slower under these circumstances compared to GCY resulting in lower rate value than in the case of GCY. Biological studies revealed that ACY exhibited a remarkable decrease in a number of viral organisms present in virus infected cell culture system using real-time polymerase chain reaction (RT-PCR). NMR analysis indicates that the chemical structure of the drug remains stable during film casting process and release.

Drug release from cast films of ethylene vinyl acetate (EVA) copolymer: Stability of drugs by 1H NMR and solid state 13C CP/MAS NMR

The study utilizes an oral biocompatible material based on ethylene vinyl acetate copolymer (EVA) designed to release drugs in vitro at therapeutic levels over several days. We examined the drug stability during film casting process using proton and solid state NMR techniques. The drug-loaded EVA films were prepared from the dry sheet obtained by solvent (dichloromethane) evaporation of polymer casting solutions. Drugs tested include chlorhexidine diacetate (CDA), doxycycline hydrochloride (DOH), tetracycline hydrochloride (TTH) and nystatin (NST). Drug release from the films was examined for at least 14 days in 10 ml ddH2O (NST in water/ethanol (4:1)) which was replaced daily. Changes in optical density were followed spectraphotometrically. Effect of temperature on rate measurements was studied and the energies of activation (E*) were calculated using Arrhenius plots. Effect of EVA copolymer composition on CDA release rate was also investigated. The enhanced rates with temperature increase may be attributed to the formation of channels with increased geometry in the polymer. The highest E* observed for CDA compared to DOH and TTH may be related to their average molecular weights. Spectral analyses for CDA and NST revealed that the chemical and physical structures of the drugs remained unaffected during the film casting process.

A polymeric device for delivery of anti-microbial and anti-fungal drugs in the oral environment: effect of temperature and medium on the rate of drug release

OBJECTIVES

The use of drug delivery systems in dentistry is a relatively new area of research with the exception of fluoride ion release from polyalkenoate cements and their predecessor silicate cements. The present study is based on the use of a bio-compatible material ethylene vinyl acetate copolymer (EVA) that enables constant release of drugs of therapeutic levels over extended periods of time at doses suitable for the treatment of oral conditions.

METHODS

Polymer casting solutions were made by dissolving EVA and the drug in the ratio of 40:1 in 70 ml of dichloromethane at 38 degrees C for 6 h. Thin square films of 3 x 3 cm2 with a thickness of 1 mm were cut from the dry sheet obtained by solvent evaporation technique. Drug loaded samples were extracted for a minimum of 14 days in 10 ml medium (double distilled water or water/ethanol (4:1)) which was replaced daily. Spectral measurements were made to follow changes in optical densities (OD) during release kinetics. Effect of temperature (24 and 37 degrees C) on the rate of drug release was studied and the energies of activation (DeltaE not equal ) were calculated using Arrehenius equation for the diffusion (translocation) of molecules of tetracycline hydrochloride (TTH), doxycycline hydrochloride (DOH), and chlorhexidine diacetate (CDA) in water as extracting medium. Effect of extracting medium (water and water/ethanol (4:1)) was also investigated on the rate of drug release measurements at 24 degrees C.

RESULTS

Analysis of variance of the data revealed that significantly enhanced rates were observed at the higher temperature (37 degrees C) and when extracting medium was changed to water/ethanol (4:1) for TTH, DOH and CDA (p<0.0015). The enhanced rate values seem to be due to the formation of channels in the polymer. The largest activation energy (21.83 kcal mol(-1)) observed for CDA was interpreted as due to the highest average molecular weight (626) compared to TTH (481) and DOH (481).Significance. These in vitro rate of drug release measurements will provide a basis for establishing a novel approach (treatment modality) for sustained intra-oral drug delivery over extended time periods using laboratory methods and materials that are readily available to dentists.

Formation of precise connections in the olfactory bulb occurs in the absence of odorant-evoked neuronal activity

Olfactory neurons expressing the same odorant receptor converge to a small number of glomeruli in the olfactory bulb. In turn, mitral and tufted cells receive and relay this information to higher cortical regions. In other sensory systems, correlated neuronal activity is thought to refine synaptic connections during development. We asked whether the pattern of connections between olfactory sensory axons and mitral cell dendrites is affected when odor-evoked signaling is eliminated in mice lacking functional olfactory cyclic nucleotide-gated (CNG) channels. We demonstrate that olfactory sensory axons converge normally in the CNG channel mutant background. We further show that the pruning of mitral cell dendrites, although slowed during development, is ultimately unperturbed in mutant animals. Thus, the olfactory CNG channel-and by inference correlated neural activity--is not required for generating synaptic specificity in the olfactory bulb.

Functional identification of a goldfish odorant receptor

The vertebrate olfactory system utilizes odorant receptors to receive and discriminate thousands of different chemical stimuli. An understanding of how these receptors encode information about an odorant's molecular structure requires a characterization of their ligand specificities. We employed an expression cloning strategy to identify a goldfish odorant receptor that is activated by amino acids-potent odorants for fish. Structure-activity analysis indicates that the receptor is preferentially tuned to recognize basic amino acids. The receptor is a member of a multigene family of G protein-coupled receptors, sharing sequence similarities with the calcium sensing, metabotropic glutamate, and V2R class of vomeronasal receptors. The ligand tuning properties of the goldfish amino acid odorant receptor provide information for unraveling the molecular mechanisms underlying olfactory coding.

Development of the vertebrate main olfactory system

Olfactory receptor neurons project from the sensory epithelium to stereotyped targets within the olfactory bulb. Recent studies suggest that the generation of this precise spatial map probably involves a hierarchy of guidance events, as receptor neurons integrate information present in the epithelium and bulb to reach their target.

Targeted neuronal cell ablation in the Drosophila embryo: pathfinding by follower growth cones in the absence of pioneers

We developed a rapid method that uses diphtheria toxin, the flp recognition target sequences, and the GAL4-UAS activation system, to ablate specific neurons in the Drosophila embryo and to examine the consequences in large numbers of embryos at many time points. We used this method to show that, in the absence of the aCC axon, which pioneers the intersegmental nerve in the PNS, the three U follower axons are delayed and make frequent errors. However, the pathway ultimately forms in most segments. We also ablated the axons that pioneer the first longitudinal pathways within the CNS and observed similar results; the formation of longitudinal pathways is delayed and disorganized in 70% of segments, but these tracts ultimately form in 80% of segments. Thus, pioneers facilitate the development of PNS and CNS axon pathways; in their absence, followers are delayed and make numerous errors. However, pioneers are not absolutely required, as these embryos display a remarkable ability to correct for the loss of the pioneering neurons.

Genetic analysis of Fasciclin II in Drosophila: defasciculation, refasciculation, and altered fasciculation

The Drosophila neural cell adhesion molecule Fasciclin II (Fas II) is expressed dynamically on a subset of embryonic CNS axons, many of which selectively fasciculate in the vMP2, MP1, and FN3 pathways. Here we show complementary fasII loss-of-function and gain-of-function phenotypes. Loss-of-function fasII mutations lead to the complete or partial defasciculation of all three pathways. Gain-of-function conditions, using a specific control element to direct increased levels of Fas II on the axons in these three pathways, rescue the loss-of-function phenotype. Moreover, the gain-of-function can alter fasciculation by abnormally fusing pathways together, in one case apparently by preventing normal defasciculation. These results define an in vivo function for Fas II as a neuronal recognition molecule that controls one mechanism of growth cone guidance-selective axon fasciculation--and genetically separates this function from other aspects of outgrowth and directional guidance.

Ectopic and increased expression of Fasciclin II alters motoneuron growth cone guidance

We used the enhancer detection/GAL4 system in Drosophila to direct increased levels of Fasciclin II (Fas II) expression on motoneuron growth cones and axons and to direct ectopic Fas II expression on other cells they encounter. Four classes of abnormal phenotypes are observed: "bypass" phenotypes, in which axons fail to defasciculate at the choice point where they would normally enter their muscle target region and instead extend past their target; "detour" phenotypes, in which these bypass growth cones enter their muscle target region at a different location; "stall" phenotypes, in which axons that enter their muscle target region fail to defasciculate from one another to probe their muscle targets; and "misroute" phenotypes, in which growth cones are diverted onto abnormal pathways by contact with Fas II-positive cells. These phenotypes show that changes in the pattern and level of Fas II expression can alter growth cone guidance, apparently in part by modulating the ability of these growth cones to respond to other guidance cues.

[Experiment and clinical significances of papillary myotomy's and septal valvotomy's resuture in the right ventricle]

In this paper, the results of the papillary myotomy and septal tricuspid valvotomy were studied. The 19 dogs were randomly divided into four groups so as to observe the blood supply, healing course, strength and functions of the anterior papillary muscle. It was confirmed that the traumatic rupture of the papillary muscle should be repaired early. In the clinic 31 patients of ventricular septal defect with tricuspid valve pouch were treated by the approach with septal valvotomy and cone papillary myotomy of tricuspid valve. The successful rate of VSD repair was up to 100%. Therefore, this approach is worthy to be used clinically.

Characterization of Star and its interactions with sevenless and EGF receptor during photoreceptor cell development in Drosophila

Loss-of-function mutations in Star impart a dominant rough eye phenotype and, when homozygous, are embryonic lethal with ventrolateral cuticular defects. We have cloned the Star gene and show that it encodes a novel protein with a putative transmembrane domain. Star transcript is expressed in a dynamic pattern in the embryo including in cells of the ventral midline. In the larval eye disc, Star is expressed first at the morphogenetic furrow, then in the developing R2, R5, and R8 cells as well as in the posterior clusters of the disc in additional R cells. Star interacts with Drosophila EGF receptor in the eye and mosaic analysis of Star in the larval eye disc reveals that homozygous Star patches contain no developing R cells. Taken together with the expression pattern at the morphogenetic furrow, these results demonstrate an early role for Star in photoreceptor development. Additionally, loss-of-function mutations in Star act as suppressors of R7 development in a sensitized genetic background involving the Son of sevenless (Sos) locus, and overexpression of Star enhances R7 development in this genetic background. Based on the genetic interactions with Sos, we suggest that Star also has a later role in photoreceptor development including the recruitment of the R7 cell through the sevenless pathway.

Colon replacement from esophagus. Clinical experience from 240 cases

The clinical experience in the colon replacement of the esophagus in 240 cases is reported. The overall operative morbidity was 17.5%; the incidence of the anastomotic leaks was 10.4%; and the mortality was 2.80%. The points in surgical technique were: 1) utilizing the left colic artery as the supporting vessel if possible, based on the anatomy of the colon vessel; 2) using the colon segment in an isoperistaltic position, which has been proved much physiological; 3) single-layer anastomosis which is simple and reliable, with minimal inflammation and quick healing; and 4) choosing the channel of the colon transplant according to the disease condition, the age, and the function of the heart and the lung of the patients.

A double-blinded comparison of metoclopramide and droperidol for prevention of emesis following strabismus surgery

Vomiting in the postoperative period is common in children after strabismus surgery. One hundred ten pediatric patients, ages 8 months to 14 yr, admitted for outpatient strabismus surgery were enrolled in a randomized, double-blinded study to compare droperidol and metoclopramide to placebo for the prevention of postoperative emesis. Each child was prospectively assigned at random to one of four treatment groups: metoclopramide 0.15 mg/kg, metoclopramide 0.25 mg/kg, droperidol 0.075 mg/kg, or saline control. Drugs were administered intravenously immediately after induction of inhalation anesthesia. No neuromuscular blocking agents were used. Tracheal extubation was performed while patients were still deeply anesthetized. Acetaminophen and meperidine were given in standard doses for postoperative pain to all children. The incidence of vomiting was less in both the droperidol (33%) and metoclopramide 0.25 mg/kg (29%) groups when compared to controls (88%) (P less than 0.01). Patients receiving metoclopramide 0.15 mg/kg had a 68% incidence of vomiting (P not significant). The mean frequency of emesis was reduced in all treatment groups compared with control (P less than 0.05). Patients receiving droperidol and metoclopramide 0.25 mg/kg also had decreased postoperative stays (metoclopramide 201 min; droperidol 213 min) versus control (258 min, P less than 0.05). No child exhibited extrapyramidal symptoms, excessive drowsiness, or agitation. We conclude that metoclopramide in a dose of 0.25 mg/kg, administered prior to the start of surgery, is at least as effective as droperidol in preventing postoperative emesis and can reduce the time to patient discharge compared to control.

Spinal tetracaine decreases central nervous system metabolism during somatosensory stimulation in the rat

The influence of spinal tetracaine on central nervous system (CNS) metabolism was determined during nociceptive stimulation. Rats were divided into a halothane group in which the sciatic nerve was stimulated during 0.5 per cent halothane anaesthesia, a tetracaine group in which the sciatic nerve was stimulated during a simultaneous tetracaine spinal and 0.5 per cent halothane anaesthetic, or an awake group. Autoradiographic determination of local spinal cord and cerebral glucose utilization was performed using 14C-2-deoxyglucose. Central nervous system metabolism was greater in the halothane group than the tetracaine and awake groups (P less than 0.05). The only meaningful differences between the tetracaine and awake groups were in two lumbar grey areas at the site of drug administration where metabolism was decreased in the tetracaine/stimulated group. These results indicate that spinal tetracaine effects a decrease in metabolism locally, and attenuates increases in metabolism throughout the CNS observed during somatosensory stimulation.