Informing the management of multiple stressors on estuarine ecosystems using an expert-based Bayesian Network model.

The approach of applying stressor load limits or thresholds to aid estuarine management is being explored in many global case studies. However, there is growing concern regarding the influence of multiple stressors and their cumulative effects on the functioning of estuarine ecosystems due to the considerable uncertainty around stressor interactions. Recognising that empirical data limitations hinder parameterisation of detailed models of estuarine ecosystem responses to multiple stressors (suspended sediment, sediment mud and metal content, and nitrogen inputs), an expert driven Bayesian network (BN) was developed and validated. Overall, trends in estuarine condition predicted by the BN model were well supported by field observations, including results that were markedly higher than random (71-84% concordance), providing confidence in the overall model dynamics. The general BN framework was then applied to a case study estuary to demonstrate the model's utility for informing management decisions. Results indicated that reductions in suspended sediment loading were likely to result in improvements in estuarine condition, which was further improved by reductions in sediment mud and metal content, with an increased likelihood of high abundance of ecological communities relative to baseline conditions. Notably, reductions in suspended sediment were also associated with an increased probability of high nuisance macroalgae and phytoplankton if nutrient loading was not also reduced (associated with increased water column light penetration). Our results highlight that if stressor limit setting is to be implemented, limits must incorporate ecosystem responses to cumulative stressors, consider the present and desired future condition of the estuary of interest, and account for the likelihood of unexpected ecological outcomes regardless of whether the experts (or empirical data) suggest a threshold has or has not been triggered.

Untapped potential of multicenter studies: a review of cardiovascular risk prediction models revealed inappropriate analyses and wide variation in reporting.

BACKGROUND: Clinical prediction models are often constructed using multicenter databases. Such a data structure poses additional challenges for statistical analysis (clustered data) but offers opportunities for model generalizability to a broad range of centers. The purpose of this study was to describe properties, analysis, and reporting of multicenter studies in the Tufts PACE Clinical Prediction Model Registry and to illustrate consequences of common design and analyses choices. METHODS: Fifty randomly selected studies that are included in the Tufts registry as multicenter and published after 2000 underwent full-text screening. Simulated examples illustrate some key concepts relevant to multicenter prediction research. RESULTS: Multicenter studies differed widely in the number of participating centers (range 2 to 5473). Thirty-nine of 50 studies ignored the multicenter nature of data in the statistical analysis. In the others, clustering was resolved by developing the model on only one center, using mixed effects or stratified regression, or by using center-level characteristics as predictors. Twenty-three of 50 studies did not describe the clinical settings or type of centers from which data was obtained. Four of 50 studies discussed neither generalizability nor external validity of the developed model. CONCLUSIONS: Regression methods and validation strategies tailored to multicenter studies are underutilized. Reporting on generalizability and potential external validity of the model lacks transparency. Hence, multicenter prediction research has untapped potential. REGISTRATION: This review was not registered.

Major conservation policy issues for biodiversity in Oceania.

Oceania is a diverse region encompassing Australia, Melanesia, Micronesia, New Zealand, and Polynesia, and it contains six of the world's 39 hotspots of diversity. It has a poor record for extinctions, particularly for birds on islands and mammals. Major causes include habitat loss and degradation, invasive species, and overexploitation. We identified six major threatening processes (habitat loss and degradation, invasive species, climate change, overexploitation, pollution, and disease) based on a comprehensive review of the literature and for each developed a set of conservation policies. Many policies reflect the urgent need to deal with the effects of burgeoning human populations (expected to increase significantly in the region) on biodiversity. There is considerable difference in resources for conservation, including people and available scientific information, which are heavily biased toward more developed countries in Oceania. Most scientific publications analyzed for four threats (habitat loss, invasive species, overexploitation, and pollution) are from developed countries: 88.6% of Web of Science publications were from Australia (53.7%), New Zealand (24.3%), and Hawaiian Islands (10.5%). Many island states have limited resources or expertise. Even countries that do (e.g., Australia, New Zealand) have ongoing and emerging significant challenges, particularly with the interactive effects of climate change. Oceania will require the implementation of effective policies for conservation if the region's poor record on extinctions is not to continue.

Transforming growth factor-beta1 mediates epithelial to mesenchymal transdifferentiation through a RhoA-dependent mechanism.

Transforming growth factor-beta1 (TGF-beta) can be tumor suppressive, but it can also enhance tumor progression by stimulating the complex process of epithelial-to-mesenchymal transdifferentiaion (EMT). The signaling pathway(s) that regulate EMT in response to TGF-beta are not well understood. We demonstrate the acquisition of a fibroblastoid morphology, increased N-cadherin expression, loss of junctional E-cadherin localization, and increased cellular motility as markers for TGF-beta-induced EMT. The expression of a dominant-negative Smad3 or the expression of Smad7 to levels that block growth inhibition and transcriptional responses to TGF-beta do not inhibit mesenchymal differentiation of mammary epithelial cells. In contrast, we show that TGF-beta rapidly activates RhoA in epithelial cells, and that blocking RhoA or its downstream target p160(ROCK), by the expression of dominant-negative mutants, inhibited TGF-beta-mediated EMT. The data suggest that TGF-beta rapidly activates RhoA-dependent signaling pathways to induce stress fiber formation and mesenchymal characteristics.

Cross-sectional geometry of the sacral ala for safe insertion of iliosacral lag screws: a computed tomography model.

OBJECTIVE: To measure the dimensions of the narrowest portion of the sacral ala for safe insertion of iliosacral lag screws. DESIGN: Computed tomography (CT) model. SETTING: Level One trauma center. PATIENTS: Thirteen adult patients underwent pelvic CT imaging. MAIN OUTCOME MEASURE: Axial CT scans of intact pelves were reformatted in the sagittal plane at three-millimeter intervals from the first sacral body (S1 body) to the sacroiliac (SI) joint. Computer analysis and measurements of sacral geometry were used to determine the narrowest portion of the bony sacral ala. The maximum height, maximum width, and slope of the sacral ala through its geometric center in cross-section were measured. RESULTS: The narrowest portion of the sacral ala in all patients was consistently located at the junction between the sacral body and the alar wings, termed the sacral pedicle, directly cephalad to the first sacral foramen. The average slope of the sacral ala at the sacral pedicle was 45.08 degrees (range 25 to 65 degrees). The average maximum height at the geometric center in cross-section was 27.76 millimeters, and the average width was 28.05 millimeters. However, outside the geometric center there was a sharp decrease in height and width of the sacral ala that was in large part determined by its relative slope. CONCLUSION: Although the cross-sectional geometry of the sacral ala is highly variable among patients, there is ample space for iliosacral screws. To ensure safe insertion, iliosacral lag screws must be positioned in the geometric center of the sacral ala to avoid extraosseous placement.

A strong negative transcriptional regulatory region between the human cytomegalovirus UL127 gene and the major immediate-early enhancer.

The region of the human cytomegalovirus (CMV) genome between the UL127 open reading frame and the major immediate-early (MIE) enhancer is referred to as the unique region. DNase I protection analysis with human cell nuclear extracts demonstrated multiple protein binding sites in this region of the viral genome (P. Ghazal, H. Lubon, C. Reynolds-Kohler, L. Hennighausen, and J. A. Nelson, Virology 174:18-25, 1990). However, the function of this region in the context of the viral genome is not known. In wild-type human CMV-infected human fibroblasts, cells permissive for viral replication, there is little to no transcription from UL127. We determined that the unique region prevented transcription from the UL127 promoter but had no effect on the divergent MIE promoter. In transient-transfection assays, the basal level of expression from the UL127 promoter increased significantly when the wild-type unique sequences were mutated. In recombinant viruses with similar mutations in the unique region, expression from the UL127 promoter occurred only after de novo viral protein synthesis, typical of an early viral promoter. A 111-bp deletion-substitution of the unique sequence caused approximately a 20-fold increase in the steady-state level of RNA from the UL127 promoter and a 245-fold increase in the expression of a downstream indicator gene. This viral negative regulatory region was also mutated at approximately 50-bp regions proximal and distal to the UL127 promoter. Although some repressive effects were detected in the distal region, mutations of the region proximal to the UL127 promoter had the most significant effects on transcription. Within the proximal and distal regions, there are potential cis sites for known eucaryotic transcriptional repressor proteins. This region may also bind unknown viral proteins. We propose that the unique region upstream of the UL127 promoter and the MIE enhancer negatively regulates the expression from the UL127 promoter in permissive human fibroblast cells. This region may be a regulatory boundary preventing the effects of the very strong MIE enhancer on this promoter.

Several isoforms of locustatachykinins may be involved in cyclic AMP-mediated release of adipokinetic hormones from the locust Corpora cardiaca.

Four locustatachykinins (LomTK I-IV) were identified in about equal amounts in extracts of corpora cardiaca of locusts, using reverse-phase high-performance liquid chromatography and radioimmunoassay with synthetic LomTK I-IV as standards. Brain extracts also contained the four isoforms in roughly equimolar concentrations. Retrograde tracing of the nervi corporis cardiaci II (NCC II) in vitro with Lucifer yellow in combination with LomTK immunocytochemistry revealed that about half of the secretomotor neurons in the lateral part of the protocerebrum projecting into the glandular lobe of the corpora cardiaca (CCG) contain LomTK-immunoreactive material. Since the four LomTKs are present in the CCG, these four or five neurons in each hemisphere are likely to contain colocalized LomTK I-IV. The role of two of the LomTKs in the regulation of the release of adipokinetic hormones (AKHs) from the adipokinetic cells in the CCG in the locust was investigated. Experiments performed in vitro showed that LomTK I and II induced release of AKH in a dose-dependent manner. These peptides also rapidly and transiently elevated the cyclic AMP-content of the CCG. The peak level of cyclic AMP occurred about 45 seconds after stimulation with LomTK. These results support the proposal that LomTKs are involved in controlling the release of the adipokinetic hormones and suggest that all LomTK isoforms may participate in this cyclic AMP-mediated event.

An aminoisobutyric acid-containing analogue of the cockroach tachykinin-related peptide, LemTRP-1, with potent bioactivity and resistance to an insect angiotensin-converting enzyme.

Nine tachykinin-related peptides (TRPs), designated LemTRP-1-9, were recently isolated from the cockroach, Leucopheae maderae. To obtain a LemTRP resistant to endo- and exoprotease-mediated hydrolysis, we synthesized a peptide with one of the carboxy terminus residues substituted for a sterically hindered aminoisobutyric acid (Aib) and with the amino terminus blocked with a pyroglutamate. The Aib-containing analogue of the nonapeptide LemTRP-1 (Aib-LemTRP-1) thus has the sequence pGlu-Ala-Pro-Ser-Gly-Phe-Leu-Aib-Val-Arg-NH2. This analogue was shown to be resistant to hydrolysis by recombinant angiotensin-converting enzyme (ACE), from Drosophila melanogaster. Endogenous LemTRP-1 on the other hand was rapidly hydrolysed by ACE at the Gly7-Val8 bond, resulting in a single heptapeptide. The Aib-LemTRP-1 has about the same potency as LemTRP-I in inducing contractions of the L. maderae hindgut muscle. It was also tested in intracellular recordings for ability to induce firing of action potentials in dorsal unpaired median (DUM) neurons in the metathoracic ganglion of the locust Locusta migratoria. The Aib-containing analogue was nearly as active as LemTRP-1 and the natural ligand locustatachykinin I. LemTRP-1 and Aib-LemTRP-1 had the same transient time course of action on the cockroach hindgut. This suggests that peptide degradation is not likely to be the cause of the transient action of TRPs.

Mechanisms of chloride transport across the syncytiotrophoblast basal membrane in the human placenta.

Chloride transport mechanisms in isolated plasma membrane vesicles were studied to characterize pathways for transcellular transport of chloride. Microvillous membrane (MVM) and basal membranes (BM) vesicles were isolated from term placentae. Western blot analysis of the anion exchanger isoform 1 (AE1) demonstrated that the density of AE1 was 12-fold higher on the MVM compared to the BM. At 30 sec, the Cl- uptake in the absence of a potential difference (p.d.) was 457.3 +/- 69.7 and 111.0 +/- 29.1 pmol/mg protein in MVM and BM, respectively (mean +/- SEM, n=6). Chloride transport pathways were characterized using diisothiocyano-2'2-disulphonic stilbene. (DIDS, 0.1 mM) and diphenylamine-2-carboxylate (DPC, 0.5 mM) in the absence or presence of inside positive membrane potentials. Anion exchange (DIDS-sensitive uptake at zero mV) was found in the MVM only. Both MVM and BM showed increased chloride uptake in the presence of inside positive potentials, suggesting the presence of chloride conductance pathways. The chloride uptake with a 25-mV inside positive p.d. could be inhibited by both DIDS and DPC in MVM and BM. However greater potentials (50 mV) showed no significant inhibition by DIDS or DPC in BM. In conclusion, the anion exchanger is unlikely to contribute significantly to chloride fluxes across BM. The data also suggest the presence of Cl- conductance pathways in both the MVM and BM which are sensitive to both DIDS and DPC.

Characterization of actions of Leucophaea tachykinin-related peptides (LemTRPs) and proctolin on cockroach hindgut contractions.

The nine Leucophaea Tachykinin-Related Peptides (LemTRP 1-9) isolated from the midgut and brain of the cockroach, Leucophaea maderae, all induced increases in spontaneous contractions of the L. maderae hindgut. Synthetic LemTRP 1 and 3-9, were equally potent in inducing contractions of the hindgut. More than seven of the nine C-terminal residues of the closely related locust peptide locustatachykinin I (LomTK I) are required for full activity of the peptide on the L. maderae hindgut. Proctolin, a well characterized myostimulatory neuropeptide, was shown to be more potent than LemTRPs. LemTRP 1 and proctolin did not have synergistic actions in potentiating the amplitude and tonus of contractions of the L. maderae hindgut. Several differences could be seen in actions of LemTRP 1 and proctolin. In contrast to proctolin, LemTRP 1 could not override the inhibitory action of 10(-9) M of the myoinhibitory peptide leucomyosuppressin. Spantide I, an antagonist of the mammalian tachykinin receptors, at a concentration of 5 microM, blocked the response to LemTRP 1, but not to proctolin. The competitive proctolin receptor antagonist [alpha-methyl-L-tyrosine2]-proctolin blocked the action of both proctolin and LemTRP 1 when applied at 1 microM, whereas cycloproctolin had no antagonist action on either peptide. Verapamil, a blocker of voltage gated Ca2+-channels, and the less specific Ca2+-channel blocker Mn2+, abolished the action of LemTRP 1, but not of proctolin. The results obtained indicate that LemTRPs act on receptors distinct from those of proctolin. Double label immunocytochemistry revealed that all LomTK-like immunoreactive fibers impinge on the proctolinergic fibers in the hindgut. This finding and the inhibitory actions of Ca2+-channel blockers on TRP responses and of the proctolin receptor antagonist on both peptides, may suggest that the LemTRP receptors are not on the hindgut muscle fibers but on the terminals of the proctolinergic neurons. Thus, LemTRPs may induce release of proctolin on the hindgut. An alternative is that LemTRPs act by mechanisms clearly distinct from those of proctolin.

Computer-assisted measurement of lumbar spine radiographs.

RATIONALE AND OBJECTIVES: The authors evaluated a method for obtaining reproducible, reliable measurements from standard lumbar spine radiographs for determining the degree of spondylolisthesis, vertebral body height, intervertebral disk space height, disk space angle, and degree of vertebral body wedging. MATERIALS AND METHODS: Four to six easily defined points were identified on each vertebral body on anteroposterior and lateral plain radiographs of the lumbosacral spine of patients. From these points, the degree of spondylolisthesis, the vertebral body height, the intervertebral disk space height, the disk space angle, and the degree of vertebral body wedging were easily calculated by using well-known geometric relationships. This method requires the use of a personal computer and a standard spreadsheet program but does not require the use of any other specialized radiographic equipment, computer hardware, or custom software. RESULTS: Calculations of intra- and interobserver variability for the measurement of spondylolisthesis, disk space height, disk space angle, and vertebral body height measurement showed that the technique is extremely reproducible. CONCLUSION: This technique may prove useful in the prospective evaluation of potential candidates for lumbar spinal stenosis surgery.

Two novel tachykinin-related peptides from the nervous system of the crab Cancer borealis.

Immunocytochemical and biochemical studies have indicated the presence of many neuroactive substances in the stomatogastric nervous system (STNS) of the crab Cancer borealis. In electrophysiological studies, many of these substances modulate the motor output of neural networks contained within this system. Previous work in the STNS suggested the presence of neuropeptides related to the invertebrate tachykinin-related peptide (TRP) family. Here we isolate and characterize two novel peptides from the C. borealis nervous system that show strong amino acid sequence identity to the invertebrate TRPs. The central nervous systems of 160 crabs were extracted in an acidified solvent, after which four reversed-phase HPLC column systems were used to obtain pure peptides. A cockroach hindgut muscle contraction bioassay and a radioimmunoassay (RIA) employing an antiserum to locustatachykinin I (Lom TK I) were used to monitor all collected fractions. The amino acid sequences of the isolated peptides were determined by Edman degradation. Mass spectrometry and chemical synthesis confirmed the sequences to be APSGFLGMR-NH2 and SGFLGMR-NH2. APSGFLGMR-NH2 is approximately 20-fold more abundant in the crab central nervous system than is SGFLGMR-NH2. We have named these peptides Cancer borealis tachykinin-related peptide Ia and Ib (CabTRP Ia and Ib), respectively. Both peptides are myoactive in the cockroach hindgut muscle contraction bioassay, with CabTRP Ia being approximately 500 times more potent than CabTRP Ib. RIA performed on HPLC-separated C. borealis stomatogastric ganglion (STG) extract revealed that CabTRP Ia is the only detectable TRP-like moiety in this ganglion. Incubation of synthetic CabTRP Ia with the isolated STG excited the pyloric motor pattern. These effects were suppressed by the broad-spectrum tachykinin receptor antagonist Spantide I. Spantide I had no effect on the actions of the unrelated endogenous peptide proctolin in the STG. There was no consistent influence of CabTRP Ib on the pyloric rhythm. Given its amino acid sequence and minimal biological activity in the crab, CabTRP Ib may be a breakdown product of CabTRP Ia.

Peptidergic activation of locust dorsal unpaired median neurons: depolarization induced by locustatachykinins may be mediated by cyclic AMP.

Four tachykinin-related peptides, locustatachykinin 1-4 (LomTK 1-4) are distributed in interneurons throughout the central nervous system of the locust Locusta migratoria and may have important roles as neurotransmitters or neuromodulators. In search of the central actions of LomTKs, we analyzed the response of the efferent dorsal unpaired median (DUM) neurons in the locust metathoracic ganglion. Immunocytochemistry, using an antiserum against LomTK 1, combined with intracellular filling of efferent DUM neurons with Lucifer yellow, revealed that LomTK-immunoreactive fibers are in close proximity to dendritic arborizations of the DUM neurons. Hence, LomTKs may act on DUM neurons by releasing locally in the metathoracic ganglion. Intracellular recordings were made from somata of DUM neurons, and LomTKs were either bath-applied to an isolated metathoracic ganglion or pressure-ejected onto the DUM neuron soma. LomTK 1 at concentrations of 0.1 mM-0.1 microM caused a relatively slow, reversible depolarization with a subsequent increase in the frequency of action potential firing. Amino-terminally truncated forms of LomTK 1 were applied to DUM neurons. The heptapeptide [3-9]-LomTK 1 had a substantially reduced activity, and bioactivity was lost after further truncation. Spantide 1, an antagonist of mammalian tachykinin receptors, reversibly blocked the effect of LomTK 1. The effect of LomTK 1 was clearly reduced in the presence of GDP-beta-S, a stable analog of GDP that inactivates G-proteins. The action of LomTK 1 was potentiated by both IBMX and theophylline, two cyclic AMP (cAMP) phosphodiesterase inhibitors. The action of LomTK 1 was mimicked by pressure-ejecting 8-bromo-cAMP, a membrane permeable analog of cAMP, and by forskolin, an adenylate cyclase activator. Furthermore, cAMPS, a blocker of protein kinase A activity, reduced the effect of LomTK 1. These findings indicate that cAMP is involved in mediating DUM neuron depolarization.

Cerebrospinal fluid proteins in subclinical and overt hypothyroidism.

PATIENTS AND METHODS: We analysed cerebrospinal fluid (CSF) albumin and immunoglobulin G (IgG) concentrations and psychometric performance in subclinical (n = 6) and overt hypothyroidism (n = 9) before and after 6 months with L-thyroxine. RESULTS: In overt hypothyroidism, CSF albumin and IgG concentrations were increased before therapy [mean(SD): 328(156) mg/l and 69(27) mg/l], but within the reference interval [198(48) mg/l and 39(11) mg/l], P < 0.05, after therapy. In contrast, in subclinical hypothyroidism CSF protein concentrations were within the reference intervals before and after therapy. Psychometric testing indicated an improvement in performance in both groups. CONCLUSION: The increase in CSF proteins in overt hypothyroidism does not appear to be related to thyroid autoimmune disease per se, since we found no increase in CSF proteins in individuals with subclinical hypothyroidism and presence of thyroid antibodies. The increase might rather be caused by a blood-brain barrier dysfunction related to low thyroid hormone concentrations.

Recording non-nutritive sucking in the neonate. Description of an automatized system for analysis.

A new method for automatic analysis of non-nutritive sucking in newborn infants is described, which uses a specially designed computer program that analyses an analogue signal obtained from a pressure transducer inside a pacifier. Validation is done with four independent methods: electromyogram, visual identification, control of the automatic treatment and comparison of inter-observer results. A high degree of correspondence is shown. The system was applied to 58 healthy full-term neonates. Infants less than 24 h old demonstrated a significantly different sucking pattern compared with the 3-day-old infant. The duration of their bursts was longer (3.7 vs 2.8 s), the frequency of their sucking was lower (1.7 vs 2.0 Hz) and the variability of their sucking pattern was greater. These results also testify to the validity of the method inasmuch as the values for the different sucking parameters are similar to corresponding values presented earlier.

Multiple members of the leucokinin neuropeptide family are present in cerebral and abdominal neurohemal organs in the cockroach Leucophaea maderae.

Two neurohemal organs of the cockroach Leucophaea maderae, the corpora cardiaca and the lateral heart nerve are known to contain leucokinin immunoreactive material. We examined the corpora cardiaca and the lateral heart nerve to establish whether these neurohemal organs store all 8 known leucokinin isoforms or if the leucokinins have a differential distribution. Extracts of corpora cardiaca and abdominal hearts with attached lateral heart nerve were separated on reversed phase high performance liquid chromatography (rpHPLC), then tested for leucokinin immunoreactivity by a radioimmunoassay (RIA) able to detect all 8 leucokinin isoforms. Extracts from brain and optic lobes were also separated and assayed in the RIA. Synthetic leucokinin 1-8 were subjected to rpHPLC and their different retention times established by RIA for reference. Leucokinin immunoreactive material originating from the corpora cardiaca and lateral heart nerves eluted in fractions corresponding to those of the synthetic leucokinin 1-8. In this study we have thus demonstrated that probably all 8 leucokinin isoforms are stored in the corpora cardiaca and the lateral heart nerve. These observations suggest that all 8 leucokinins are likely to be released as neurohormones into the circulation.

Evidence that histamine is a neurotransmitter in an insect extraocular photoreceptor pathway

The pair of vasopressin-like immunoreactive (VPLI) neurones of the locust Locusta migratoria have cell bodies in the suboesophageal ganglion and extensive arborization throughout the central nervous sytem. The activity of the VPLI neurone is regulated by a spontaneously active excitatory descending interneurone (DI) that is, in turn, inhibited by an uncharacterised extraocular photoreceptor (EOP) system located in the brain. Light directed at the brain results in inhibition of DI activity, which thereby deprives the VPLI neurone of its major synaptic input. We present evidence that histamine plays an important role in the EOP­DI­VPLI pathway. Histamine mimics the EOP-mediated inhibition of the DI, and the H2-specific histamine antagonists cimetidine and ranitidine block its inhibitory action. Histamine application to various areas of the brain localises the area where histaminergic inhibition occurs; this region is confined to the medial protocerebrum. At least six bilaterally paired histamine-like immunoreactive neurones send axonal projections into this area. Depolarisation of the brain region containing the soma of these neurones with high-K+ saline deactivates the VPLI neurone through the removal of the DI excitatory synaptic input.

Several forms of callitachykinins are distributed in the central nervous system and intestine of the blowfly Calliphora vomitoria.

We have examined the distribution of two tachykinin-related neuropeptides, callitachykinin I and II (CavTK-I and CavTK-II), isolated from whole-animal extracts of the blowfly Calliphora vomitoria. Extracts of dissected brains, thoracic-abdominal ganglia and midguts of adult blowflies and the entire central nervous system of larval flies were analysed by high performance liquid chromatography (HPLC) combined with enzyme-linked immunosorbent assay (ELISA) for the presence of CavTKs. To identify the two neuropeptides by HPLC, we used the retention times of synthetic CavTK-I and II as reference and detection with an antiserum raised to locustatachykinin II (shown here to recognise both CavTK-I and II). The brain contains only two immunoreactive components, and these have exactly the same retention times as CavTK-I and II. The thoracic-abdominal ganglia and midgut contain immunoreactive material eluting like CavTK-I and II as well as additional material eluting later. The larval central nervous system (CNS) contains material eluting like CavTK-I and II as well as a component that elutes earlier. We conclude that CavTK-I and II are present in all assayed tissues and that additional, hitherto uncharacterised, forms of tachykinin-immunoreactive material may be present in the body ganglia and midgut as well as in the larval CNS. An antiserum was raised to CavTK-II for immunocytochemistry. This antiserum, which was found to be specific for CavTK-II in ELISA, labelled all the neurones and midgut endocrine cells previously shown to react with the less selective locustatachykinin antisera. It is not clear, however, whether CavTK-I and II are colocalised in all LomTK-immunoreactive cells since there is no unambiguous probe for CavTK-I.

Abundant distribution of locustatachykinin-like peptide in the nervous system and intestine of the cockroach Leucophaea maderae.

An antiserum raised to the locust neuropeptide locustatachykinin I (LomTK I) was used for analysis of the distribution of tachykinin-related peptide in the cockroach Leucophaea maderae. Extracts of dissected brains, suboesophageal ganglia, thoracic ganglia and midguts were separated by high performance liquid chromatography and the fractions analysed in enzyme-linked immunosorbent assay with use of the LomTK antiserum. Each of the tissues was found to contain LomTK-like immunoreactive (LomTK-LI) components with retention times corresponding approximately to synthetic LomTK I and II and callitachykinins I and II. The LomTK antiserum was also used for immunocytochemical mapping of peptide in the nervous system and intestine of L. maderae. A large number of LomTK-LI interneurons were detected in the proto-, deuto- and tritocerebrum of the brain and in the suboesophaegeal ganglion. The immunoreactive neurons supply processes to most parts of the brain: the central body, protocerebral bridge, mushroom body calyces, antennal lobes, optic lobe and most regions of the non-glomerular neuropil. A few protocerebral neurons send LomTK-LI processes to the glandular lobe of the corpora cardiaca. In each of the thoracic ganglia there are six LomTK-LI interneurons and in each of the unfused abdominal ones there are two interneurons. The fused terminal ganglion contains some additional cell bodies in the posterior neuromers. LomTK-LI cell bodies were detected in the frontal ganglion and fibres were seen in this ganglion as well as in the hypocerebral ganglion. The frontal ganglion supplies LomTK-LI processes to the muscle layer of the pharynx. The muscle layer of the midgut is innervated by LomTK-LI fibres from the stomatogastric system (oesophageal nerve and associated ganglia). Additionally the midgut contains numerous LomTK-LI endocrine cells. A number of the pharyngeal dilator muscles were also found to be innervated by LomTK-LI fibres, probably derived from cell bodies in the suboesophageal ganglion. All the LomTK-LI neurons of the central nervous system appear to be interneurons, suggesting a neuromodulatory role of the endogenous tachykinins. The tachykinin-like peptides from peripheral ganglia may be involved in the control of foregut and midgut contractility and possibly the peptide of the endocrine cells in the midgut has additional actions related to intestinal function.

Dialysis-related Arthropathy in Patients on Long-term Hemodialysis: Radiographic Features.

The purpose of this study was to evaluate the character and evolution of bone lesions attributable to amyloid deposition in patients on long-term dialysis. Thirty-five patients who were treated with hemodialysis for 5 to 22 years were studied by a review of medical records and hand radiographs. The frequency, distribution, character, and evolution of skeletal cyst-like lesions believed to be secondary to amyloid deposition were evaluated in relation to dialysis duration. The number and size of these lesions increased with dialysis duration, present in 28% of the patients after 5 through 9 years of hemodialysis and in 91% after 15 through 22 years. In contrast, the changes of hyperparathyroidism decreased. Of patients with skeletal wrist lesions, radiographs of symptomatic large joints were available in 15; five had bone abnormalities. Skeletal amyloid deposition was verified pathologically in nine sites (five patients). It is concluded that skeletal lesions believed to be due to amyloid deposition increase with dialysis duration and most commonly affect the wrists. They have a distinctive character, distribution, and evolution and are often associated with carpal tunnel syndrome.