Creation of an international registry to support discovery in schwannomatosis.

Schwannomatosis is a tumor suppressor syndrome that causes multiple tumors along peripheral nerves. Formal diagnostic criteria were first published in 2005. Variability in clinical presentation and a relative lack of awareness of the syndrome have contributed to difficulty recognizing affected individuals and accurately describing the natural history of the disorder. Many critical questions such as the mutations underlying schwannomatosis, genotype-phenotype correlations, inheritance patterns, pathologic diagnosis of schwannomatosis-associated schwannomas, tumor burden in schwannomatosis, the incidence of malignancy, and the effectiveness of current, or new treatments remain unanswered. A well-curated registry of schwannomatosis patients is needed to facilitate research in field. An international consortium of clinicians and scientists across multiple disciplines with expertise in schwannomatosis was established and charged with the task of designing and populating a schwannomatosis patient registry. The International Schwannomatosis Registry (ISR) was built around key data points that allow confirmation of the diagnosis and identification of potential research subjects to advance research to further the knowledge base for schwannomatosis. A registry with 389 participants enrolled to date has been established. Twenty-three additional subjects are pending review. A formal process has been established for scientific investigators to propose research projects, identify eligible subjects, and seek collaborators from ISR sites. Research collaborations have been created using the information collected by the registry and are currently being conducted. The ISR is a platform from which multiple research endeavors can be launched, facilitating connections between affected individuals interested in participating in research and researchers actively investigating a variety of aspects of schwannomatosis. © 2016 Wiley Periodicals, Inc.

Remote synchronization in star networks.

We study phase synchronization in a network motif with a starlike structure in which the central node's (the hub's) frequency is strongly detuned against the other peripheral nodes. We find numerically and experimentally a regime of remote synchronization (RS), where the peripheral nodes form a phase synchronized cluster, while the hub remains free with its own dynamics and serves just as a transmitter for the other nodes. We explain the mechanism for this RS by the existence of a free amplitude and also show that systems with a fixed or constant amplitude, such as the classic Kuramoto phase oscillator, are not able to generate this phenomenon. Further, we derive an analytic expression which supports our explanation of the mechanism.

Organ-cocultures (COCs) for long term in vitro studies of lung cancer using 2-photon microscopy.

Three-dimensional organ cultures allow performing research in vitro in a complex multi-cellular environment. We aimed at developing a long term coculture system (COC) for the study of lung cancer to repeatedly measure tumor volume. Organ cultures of bronchial mucosa with 1-2 mm diameter were embedded in agarose and bisected with a tissue slicer so that the organ culture within was cut into halves uncovering the connective tissue of the stroma of each half. A cell suspension of GFP-transfected EPLC 32M1 lung tumor cells was brought in contact with the connective tissue of the wounded surface. Adherent tumor cells grew invasively into the organ culture. Using 2-Photon microscopy, Z-stacks were recorded, reconstructed with appropriate analysis software, and the tumor volume was calcvulated. Tumor cells were identified by GFP-fluorescence. Repeated measurements of the same COC could be performed over up to 8 weeks. The tumor volume increased continually with the growth rate becoming slower towards the end of culture. A comparison of two clones of tumor cells which had shown different rates of proliferation in monolayer culture demonstrated that the clone with the higher rate of proliferation in monoculture produced tumors with more rapid growth in the COC model. In this study we present a coculture system for the study of lung cancer using 2-Photon microscopy. COCs are particularly appropriate for long term in vitro treatment studies.

[Interventional bronchoscopy in lung cancer]. / Bronchoskopische Therapieverfahren beim Lungenkarzinom.

Stenosis of central airways or hemoptysis are classical indications for interventional bronchoscopy in lung cancer. In the case of endoluminal tumor growth cryo-, laser- or brachytherapy are widely used. In the case of airway stenosis due to compression by extraluminal tumor masses balloon-dilatation and/or stenting and - with delayed effect - brachytherapy are first-choice therapies. Carcinoma in situ and early stage tumors can be treated curatively with brachytherapy or photodynamic therapy. Recently introduced bronchoscopic techniques like electro-magnetic navigation may result in new curative options for peripheral lung tumors.

[Multimorbidity and successful aging: the population-based KORA-Age study]. / Multimorbidität und erfolgreiches Altern: Ein Blick auf die Bevölkerung im Rahmen der KORA-Age-Studie.

BACKGROUND: The objective of the KORA-Age research consortium is to assess the determinants and consequences of multimorbidity in the elderly and to look into reasons for successful aging in the general public. PATIENTS AND METHODS: In the KORA-Age cohort study 9,197 persons were included who where born in the year 1943 or before and participants of previous KORA cohort studies conducted between 1984 and 2001 (KORA: Cooperative Health Research in the Region of Augsburg). The randomized intervention study KORINNA (Coronary infarct follow-up treatment in the elderly) tested a nurse-based case management program with 338 patients with myocardial infarct and included an evaluation in health economics. RESULTS: A total of 2,734 deaths were registered, 4,565 participants submitted a postal health status questionnaire and 4,127 participants were interviewed by telephone (response 76.2% and 68.9% respectively). A gender and age-stratified random sample of the cohort consisting of 1,079 persons took part in a physical examination (response 53.8%). CONCLUSION: The KORA-Age consortium was able to collect data in a large population-based sample and is contributing to the understanding of multimorbidity and successful aging.

Effects of cigarette smoke extract and nicotine on bronchial tone and acetylcholine-induced airway contraction in mouse lung slices.

BACKGROUND: Tobacco smoke is a key risk factor for chronic obstructive pulmonary disease, but it may also alter the pathophysiology of asthma. In the present study, we analyzed whether tobacco smoke has acute or chronic effects on bronchial tone and whether it alters bronchial reactivity in vitro. METHODS: Airways in murine lung slices were digitally recorded and the change in cross-sectional area with time was quantified. T-bet KO mice served as a model for bronchial hyperreactivity. T-bet KO mice show a shift towards type 2 helper T lymphocytes and display histological as well as functional characteristics of asthma. Cigarette smoke extract (CSE) was obtained using commercially available cigarettes (Gauloise Blondes) by drawing cigarette smoke slowly through a water pump into a tube containing 10 mL of DMEM culture medium. RESULTS: Acute exposure to CSE led to relaxation of the airway. Acute exposure to nicotine resulted in a minor relaxation of the airway in Balb/C mice and in nonsignificant relaxation of the airway in T-bet KO mice. The nicotinic acetylcholine-receptor hexamethonium partially inhibited CSE-induced airway relaxation. Airway contraction in response to acetylcholine was stronger in T-bet KO mice than in Balb/C mice. After exposure to CSE or nicotine for 48 hours, acetylcholine-induced airway contraction was no longer different between the 2 types of mice. CONCLUSIONS: Our data indicate that acute exposure to CSE leads to airway relaxation, which is partially mediated by nicotine. Chronic exposure to CSE reverses bronchial hyperreactivity in the airways of T-bet KO mice; this effect can be mimicked by chronic exposure to nicotine.

Discrimination of cancerous and non-cancerous cell lines by headspace-analysis with PTR-MS.

Proton transfer reaction mass spectrometry (PTR-MS) has been used to analyze the volatile organic compounds (VOCs) emitted by in-vitro cultured human cells. For this purpose, two pairs of cancerous and non-cancerous human cell lines were selected:1. lung epithelium cells A-549 and retinal pigment epithelium cells hTERT-RPE1, cultured in different growth media; and 2. squamous lung carcinoma cells EPLC and immortalized human bronchial epithelial cells BEAS2B, cultured in identical growth medium. The VOCs in the headspace of the cell cultures were sampled: 1. online by drawing off the gas directly from the culture flask; and 2. by accumulation of the VOCs in PTFE bags connected to the flask for at least 12 h. The pure media were analyzed in the same way as the corresponding cells in order to provide a reference. Direct comparison of headspace VOCs from flasks with cells plus medium and from flasks with pure medium enabled the characterization of cell-line-specific production or consumption of VOCs. Among all identified VOCs in this respect, the most outstanding compound was m/z = 45 (acetaldehyde) revealing significant consumption by the cancerous cell lines but not by the non-cancerous cells. By applying multivariate statistical analysis using 42 selected marker VOCs, it was possible to clearly separate the cancerous and non-cancerous cell lines from each other.

Introduction of sapropterin dihydrochloride as standard of care in patients with phenylketonuria.

Sapropterin dihydrochloride, a synthetic, stable form of the tetrahydrobiopterin cofactor of phenylalanine hydroxylase, has been shown to reduce plasma phenylalanine (Phe) levels in a significant portion of patients with phenylketonuria (PKU). When we undertook introducing this medication to our PKU clinic population, the challenges of recalling and reconnecting with a variably treated and variably compliant patient population became apparent. We offered a trial of sapropterin to all of our clinic patients with PKU. In order to determine responsiveness, we used a two tier dose escalation protocol. After diet records were taken, and baseline plasma Phe levels were established, a 7-day trial of sapropterin at 10mg/kg/day was started. At day 8, plasma phenylalanine levels were measured. Patients were considered to be responders if they had a 30% reduction in plasma Phe. If they did not respond, the dose of sapropterin was increased to 20 mg/kg/day, and levels were rechecked again in 8 days. Patients who were not responders at this time continued sapropterin for a total of 30 days and had Phe levels checked one last time. Patients who were responders and who were on a Phe-restricted diet underwent gradual liberalization of their diet to the maximum tolerated natural protein intake while still maintaining plasma levels in the acceptable treatment range of 120-360 micromol/L. In our population, 36/39 patients with hyperphenylalaninemia (HPA) who were offered a trial of sapropterin elected to start sapropterin. Five of 36 patients were non-adherent with diet records and/or medication doses and we were unable to determine if they were responders. We were unable to categorize 2 of 31 of the patients who completed the trial as responders due to dietary issues, though they were probably responders. Of the 29 patients who completed the sapropterin trial and we could categorize, 18/29 (62%) were determined to be responders. Patients were classified based on their off-diet diagnostic plasma phenylalanine levels as classical PKU (>1200 micromol/L) and variant PKU (>400 and <1200 micromol/L). The group with variant PKU had a 100% response rate, and patients with classical PKU had a 27% response rate. For the patients in the responder group who were on Phe-restricted diet, we were able to liberalize most diets, in two cases to unrestricted protein intake. We also had unexpected beneficial findings in our clinic experience, including positive behavioral improvements in an adult severely affected by untreated PKU. Even in patients who were not considered to be responders, the introduction of sapropterin provided a tool to reconnect with patients and re-introduce beneficial dietary measures.

Regulation of the endoplasmic reticulum Ca(2+)-store in cancer.

Calcium is a ubiquitous second messenger and is involved in virtually all cellular functions. Cellular events being regulated by calcium include gene transcription, metabolism, proliferation and apoptosis. Cancer growth is based on increased proliferation, decreased differentiation and decreased apoptosis. Therefore, the intracellular Ca(2+)-homeostasis has become one of the focuses in current cancer research. Elevation of the cytoplasmic Ca(2+)-concentration can result from Ca(2+)-influx from the extracellular space or from Ca(2+)-release from intracellular stores. The main intracellular Ca(2+)-store is the endoplasmic reticulum (ER). The Ca(2+)-content of the ER is maintained by trans-membrane proteins involving the sarco/endoplasmic reticulum Ca(2+)-ATPase and the inositol-1,4,5-phosphat receptor. In this review, we summarize the current knowledge of the ER and its trans-membrane proteins as regulating structures of the intracellular Ca(2+)-homeostasis, what changes occur in malignant cells and how this promotes cancer. We further review possible pharmacological intervention and show future perspectives of the intracellular Ca(2+)-homeostasis as an anti-cancer target.

Continuous wavelet transform in the analysis of burst synchronization in a coupled laser system.

The transition to synchronization of a pair of coupled chaotic CO2 lasers is investigated numerically in a model system. This system displays episodes of bursting of different predominant frequencies. Due to the multiple time scales present in this system, we use a complex continuous wavelet transform to perform the synchronization analysis. Thus it enables us to resolve the time of occurrence as well as the frequency of an event in a given time series up to an intrinsic uncertainty. Furthermore, due to the complex nature of that wavelet transform, it yields a direct estimate of the system's phase. We show that, as the coupling strength of the laser system is increased, the mutual coherency increases differently for different frequencies. Additionally we test our method with experimental data.

Effects of different regions of the developing gut on the migration of enteric neural crest-derived cells: a role for Sema3A, but not Sema3F.

The enteric nervous system arises from vagal (caudal hindbrain) and sacral level neural crest-derived cells that migrate into and along the developing gut. Data from previous studies have suggested that (i) there may be gradients along the gut that induce the caudally directed migration of vagal enteric neural precursors (ENPs), (ii) exposure to the caecum might alter the migratory ability of vagal ENPs and (iii) Sema3A might regulate the entry into the hindgut of ENPs derived from sacral neural crest. Using co-cultures we show that there is no detectable gradient of chemoattractive molecules along the pre-caecal gut that specifically promotes the caudally directed migration of vagal ENPs, although vagal ENPs migrate faster caudally than rostrally along explants of hindgut. Exposure to the caecum did not alter the rate at which ENPs colonized explants of hindgut, but it did alter the ability of ENPs to colonize the midgut. The co-cultures also revealed that there is localized expression of a repulsive cue in the distal hindgut, which might delay the entry of sacral ENPs. We show that Sema3A is expressed by the hindgut mesenchyme and its receptor, neuropilin-1, is expressed by migrating ENPs. Furthermore, there is premature entry of sacral ENPs and extrinsic axons into the distal hindgut of fetal mice lacking Sema3A. These data show that Sema3A expressed by the distal hindgut regulates the entry of sacral ENPs and extrinsic axons into the hindgut. ENPs did not express neuropilin-2 and there was no detectable change in the timetable by which ENPs colonize the gut in mice lacking neuropilin-2.

[Ca2+-signaling in smooth muscles cells of the airways in T-bet knock-out mice]. / Ca2+-signaling in glatten Muskelzellen der Luftwege in T-bet Knock-Out Mäusen.

BACKGROUND: Airway smooth muscle cells (ASMC) play a key role in bronchial hyperresponsiveness (BHR). A major component of the signalling cascade leading to ASMC contraction is calcium. T-bet knock-out (KO) mice show the key features of allergic asthma such as a shift towards T (H2)-lymphocytes and display a broad spectrum of asthma-like histological and functional characteristics. In this study, we aimed at investigating whether Ca (2+)-homeostasis of ASMC is altered in T-bet KO-mice as an experimental model of asthma. METHODS: Lung slices of 100 to 200 microm thickness were obtained from T-bet KO- and wild-type mice. Airway contractions in response to acetylcholine (ACH) were measured by video-microscopy and Ca (2+)-signaling in single ASMC of lung slices was assessed using two-photon microscopy. RESULTS: Airways from T-bet KO-mice showed increased baseline airway tone (BAT) and BHR compared to those of wild-type mice. The increased BAT was correlated with an increased incidence of spontaneous changes in intracellular Ca (2+)-concentrations, whereas BHR correlated with higher ACH-induced Ca (2+)-transients and an increased proportion of ASMC showing Ca (2+)-oscillations. Emptying intracellular Ca (2+)-stores using caffeine or cyclopiazonic acid induced higher Ca (2+)-elevations in ASMC from T-bet KO compared to wild-type mice. CONCLUSIONS: Altered Ca (2+)-homeostasis of ASMC contributes to increased BAT and BHR in lung slices from T-bet KO mice as a murine asthma model. We propose that a higher Ca (2+)-content of the intracellular Ca (2+)-stores is involved in the pathophysiology of these changes.

How many types of cholinergic sympathetic neuron are there in the rat stellate ganglion?

Sympathetic cholinergic postganglionic neurons are present in many sympathetic ganglia. Three classes of sympathetic cholinergic neuron have been reported in mammals; sudomotor neurons, vasodilator neurons and neurons innervating the periosteum. We have examined thoracic sympathetic ganglia in rats to determine if any other classes of cholinergic neurons exist. We could identify cholinergic sudomotor neurons and neurons innervating the rib periosteum, but confirmed that cholinergic sympathetic vasodilator neurons are absent in this species. Sudomotor neurons contained vasoactive intestinal peptide (VIP) and calcitonin gene-related peptide (CGRP) and always lacked calbindin. Cholinergic neurons innervating the periosteum contained VIP and sometimes calbindin, but always lacked CGRP. Cholinergic neurons innervating the periosteum were usually surrounded by terminals immunoreactive for CGRP. We conclude that if any undiscovered populations of cholinergic neurons exist in the rat thoracic sympathetic chain, then they are indistinguishable in size, neurochemistry and inputs from sudomotor or cholinergic neurons innervating the periosteum. It may be that the latter two populations account for all cholinergic neurons in the rat thoracic sympathetic chain ganglia.

Bronchial hyperreactivity is correlated with increased baseline airway tone.

Physiologically, airways are not completely relaxed but maintain a baseline airway tone (BAT). Although not fulfilling the criteria for obstructive airway disease, increased BAT may nevertheless be important because the same amount of airway narrowing can be well tolerated or can cause severe airway obstruction depending on the starting point of the narrowing. In this study, we aimed at studying if BAT is correlated with bronchial hyperreactivity (BHR). For in vitro studies, airways in murine lung slices were digitally recorded and the change in cross-sectional area with time was quantified. BAT was measured by the amount of relaxation induced by permeabilization of the cell membrane with beta-escin in zero external calcium. BHR was induced by incubation of lung slices with interleukin-13 (IL-13). T-bet knock-out mice served as an additional model for BHR. T-bet knock-out mice show a shift towards TH2-lymphocytes and display histological as well as functional characteristics of asthma. In vivo, the specific airway resistance of healthy non-smoking volunteers was assessed before and after inhalation of formoterol and bronchial challenge was performed using methacholin. In murine lung slices that had been cultivated without serum, only a minimal BAT could be observed. But, after cultivation with 10 % new born calve serum, airways showed a BAT of approximately 13 % that could be reduced by incubation with an IL-13 receptor antagonist. Atropine, isoproterenol and indomethacin failed to relax airways regardless of cultivation with serum. Incubation of lung slices without serum but with IL-13 increased BAT as well as airway responsiveness to acetylcholine and both effects were more pronounced in small compared to large airways. In lung slices from T-bet knock-out mice, airways were hyperreactive compared to airways in slices from wild type mice and BAT was found to be increased. Again, both effects were more pronounced in small compared to large airways. In human non-smokers without airway obstruction, increased BAT was correlated with bronchial hyperreactivity. We therefore conclude that although not fulfilling the criteria for obstructive airway disease, increased airway tone may yet be relevant in asthma.

Monitoring of expiratory flow rates and lung volumes during a high altitude expedition.

BACKGROUND: Data on lung volumes and changes in flow-volume spirometry at high altitude are few and do not provide comprehensive assessment of the occurring changes. This study characterizes alterations of the forced expiratory flow-volume curve (FEFV-curve) and lung volumes at increasing altitude. METHODS: FEFV-curve and lung volumes at increasing altitude were characterized by daily assessment of peak expiratory flow (PEF), forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and maximal expiratory flow rates (MEF 25, 50, 75) at 25%, 50% and 75% of the FEFV-curve with a portable spirometer (turbinometric method) three times a day during an expedition to Mustagh Ata (7545m) in 15 healthy mountaineers. RESULTS: With increasing altitude FVC and FEV1 were reduced by up to 25% (74.8% / 74.6% of baseline) and MEF25 was reduced to 81.5% of baseline values. PEF initially increased up to 4451m and returned to baseline values above 5000m. After descent below 2000m, all values normalized within one day. There were weak negative correlations between AMSS and FEV1, FVC and PEF (r = -0.23, p<0.001). CONCLUSIONS: We found increasing pulmonary restriction at high altitude without a marked reduction of PEF. Assessment of the FEFV-curve at high altitudes with a portable spirometer is a practical method reflecting the true field situation and may provide clinically relevant information (impending pulmonary edema).

Cell cycle effects of radiation on human bronchial epithelium and lung carcinoma cells in monolayer cultures and a three-dimensional co-culture system.

The aim of this study was to investigate whether the three-dimensional structure of the bronchial tissue and the contact of non-malignant with malignant cells influence the effectiveness of radiotherapy. Monolayer cultures of cells of the human bronchial epithelial cell line BEAS 2B, monolayer co-cultures of BEAS 2B cells and cells of the GFP-transfected lung carcinoma cell line EPLC 32M1, organ cultures of human bronchial epithelium, and organ co-cultures with EPLC 32M1 cells were irradiated with 10 Gy, and the DNA content was analyzed using flow cytometry. In non-malignant epithelial cells, BEAS 2B monolayer cultures without tumor cells were highly radiosensitive. However, contact with tumor cells in monolayer co-cultures markedly reduced radiosensitivity. Non-malignant cells in three-dimensional organ cultures and organ co-cultures with tumor cells showed moderate radiosensitivity. In EPLC 32M1 tumor cells, proliferation was increased without irradiation when the cells were in contact with epithelial cells in both organ and monolayer co-cultures. Radiosensitivity was higher in organ co-cultures than in monolayer cultures and monolayer co-cultures. These data indicate that organ co-cultures in combination with flow cytometry allow investigation of the effects of radiation in an in vivo-like environment and that both the spatial organization and the interaction of non-malignant and tumor cells are crucial for the effectiveness of radiotherapy.

The location and phenotype of proliferating neural-crest-derived cells in the developing mouse gut.

Neural crest cells that originate in the caudal hindbrain migrate into and along the developing gastrointestinal tract to form the enteric nervous system. While they are migrating, neural-crest-derived cells are also proliferating. Previous studies have shown that the expression of glial-derived neurotrophic factor (GDNF) and endothelin-3 is highest in the embryonic caecum, and that GDNF alone or in combination with endothelin-3 promotes the proliferation of enteric neural-crest-derived cells in vitro. However, whether neural proliferative zones, like those in the central nervous system, are found along the developing gut is unknown. We used a fluorescent nucleic acid stain to identify dividing cells or BrdU labelling (2 h after administration of BrdU to the mother), combined with antibodies specific to neural crest cells to determine the percentage of proliferating crest-derived cells in various gut regions of embryonic day 11.5 (E11.5) and E12.5 mice. The rate of proliferation of crest-derived cells did not vary significantly in different regions of the gut (including the caecum) or at different distances from the migratory wavefront of vagal crest-derived cells. The phenotype of mitotic enteric crest-derived cells was also examined. Cells expressing the pan-neuronal markers, neurofilament-M and Hu, or the glial marker, S100b, were observed undergoing mitosis. However, no evidence was found for proliferation of cells expressing neuron-type-specific markers, such as nitric oxide synthase (at E12.5) or calcitonin gene-related peptide (at E18.5). Thus, for enteric neurons, exit from the cell cycle appears to occur after the expression of pan-neuronal proteins but prior to the expression of markers of terminally differentiated neurons.

Dynamics of neural crest-derived cell migration in the embryonic mouse gut.

Neural crest-derived cells that form the enteric nervous system undergo an extensive migration from the caudal hindbrain to colonize the entire gastrointestinal tract. Mice in which the expression of GFP is under the control of the Ret promoter were used to visualize neural crest-derived cell migration in the embryonic mouse gut in organ culture. Time-lapse imaging revealed that GFP(+) crest-derived cells formed chains that displayed complicated patterns of migration, with sudden and frequent changes in migratory speed and trajectories. Some of the leading cells and their processes formed a scaffold along which later cells migrated. To examine the effect of population size on migratory behavior, a small number of the most caudal GFP(+) cells were isolated from the remainder of the population. The isolated cells migrated slower than cells in large control populations, suggesting that migratory behavior is influenced by cell number and cell-cell contact. Previous studies have shown that neurons differentiate among the migrating cell population, but it is unclear whether they migrate. The phenotype of migrating cells was examined. Migrating cells expressed the neural crest cell marker, Sox10, but not neuronal markers, indicating that the majority of migratory cells observed did not have a neuronal phenotype.

Effects of single-dose irradiation on bronchial epithelium: a comparison of BEAS 2B cell monolayers, human organ cultures, and Goettinger minipigs.

To assess the effects of radiation on bronchial epithelium, BEAS 2B cells cultured as monolayers and human bronchial epithelium cultured as organ cultures were exposed to single doses of 0, 10 and 30 Gy. The lactate dehydrogenase in the supernatant of the BEAS 2B cells increased markedly 24 h after irradiation, whereas in the organ cultures only a minor increase was found after 48 h. The nucleosomes in the supernatant of the BEAS 2B cells showed a massive increase in response to irradiation, whereas in the organ cultures no change could be seen. The number of BEAS 2B cells was dramatically diminished after 96 h, whereas in the organ cultures a smaller decrease was observed no earlier than 21 days after irradiation. To assess the effects of brachytherapy in bronchial epithelium in vivo, brachytherapy with 30 Gy was performed in Goettinger minipigs, and histological sections of the bronchi were analyzed for morphological alterations and cell numbers. After 2 weeks, only slight cell damage was observable, and after 3 weeks, moderate morphological changes and decreased cell numbers were found. However, after 8 weeks, the epithelium had nearly regained its normal structure. We conclude that the bronchial epithelium has a remarkably high radioresistance and that organ cultures, but not monolayers of BEAS 2B cells, reflect the effects of radiation in vivo.

Control of postganglionic neurone phenotype by the rat pineal gland.

As neurones develop they are faced with choices as to which genes to express, to match their final phenotype to their role in the nervous system. A number of processes can guide these decisions. Within the autonomic and sensory nervous systems, there are a handful of examples that suggest that one mechanism that may match phenotype to function is the presence of target-derived differentiation factors. We tested whether the rat pineal gland controls the expression of a neuropeptide (neuropeptide Y) and a calcium-binding protein (calbindin) in sympathetic postganglionic neurones that innervate it. We first showed that the chemical phenotype of sympathetic neurones innervating the rat pineal includes the expression of both neuropeptide Y and the calcium-binding protein, calbindin. After transplanting the pineal gland of neonatal rats into the submandibular salivary gland of neonatal hosts, it was innervated by sympathetic axons from the surrounding salivary gland tissue, which do not normally express neuropeptide Y and calbindin. The presence of the pineal gland led to the appearance of neuropeptide Y and calbindin in many of the postganglionic neurones that innervated the graft. From these findings we suggest that, like the rodent sweat gland, the pineal gland generates a signal that can direct the neurochemical phenotype of innervating sympathetic neurones.