Impact of organochlorine contamination on levels of sex hormones and external morphology of common snapping turtles (Chelydra serpentina serpentina) in Ontario, Canada

Recent research has suggested that contaminants in the environment may influence sex differentiation and reproductive endocrine function in wildlife. Concentrations of organochlorine contaminants (total polychlorinated biphenyls, pesticides) were higher in the blood plasma of snapping turtles from contaminated sites than in those from reference sites. The ratio of the precloacal length to the posterior lobe of the plastron (PPR) is sexually dimorphic in snapping turtles. There were significant reductions in the PPR at three contaminated sites versus two reference sites. The magnitude of the response was such that a significantly higher proportion of PPRs of males from a contaminated site (Cootes Paradise) overlapped with those of females than PPRs of males from a reference site (Lake Sasajewun). Observers can incorrectly identify the sex of turtles at the contaminated site based on secondary sexual characteristics alone. Unlike the changes to the morphology, there were few changes in 17 beta-estradiol or testosterone levels, and where differences occurred, there was more variation among reference sites than between the reference and contaminated sites. Our results suggest that environmental contaminants may affect sexually dimorphic morphology in snapping turtles without affecting circulating testosterone or estrogen levels in the adults.

Environmental contamination and developmental abnormalities in eggs and hatchlings of the common snapping turtle (Chelydra serpentina serpentina) from the Great Lakes-St Lawrence River basin (1989-1991)

During 1989-1991, we assessed developmental abnormalities in embryos and hatchlings from eggs of the common snapping turtle (Chelydra serpentina serpentina). Eggs were collected and artificially incubated from eight sites in Ontario, Canada and Akwesasne/New York, USA. In eggs from the same clutches we measured 20 organochlorine pesticides, 48 polychlorinated biphenyl (PCBs) congeners including 6 non-ortho PCBs, 8 polychlorinated dibenzodioxins (PCDDs), 14 polychlorinated dibenzofurans (PCDFs) and total mercury. We found a significant increase in abnormal development with increasing polychlorinated aromatic hydrocarbon exposure in eggs, particularly PCDD and PCDF concentrations. In contrast, the risk of abnormality was not significantly higher as toxic equivalent concentrations increased in eggs. We also found significant 7-ethoxyresorufin O-deethylase and Cytochrome P4501A responses in livers of hatchling turtles from Lake Ontario relative to hatchlings from a clean, inland site whereas we did not find any evidence of porphyria in the hatchlings from either site.

Temporal and geographic variation of organochlorine residues in eggs of the common snapping turtle (Chelydra serpentina serpentina) (1981-1991) and comparisons to trends in the herring gull (Larus argentatus) in the Great Lakes basin in Ontario, Canada

Common snapping turtle (Chelydra serpentina serpentina) eggs from five sites within the Great Lakes basin, and from a reference site in north-central Ontario were collected during 1981-1991 and analyzed for four organochlorine pesticides, polychlorinated biphenyls (PCBs) including six non-ortho PCBs, polychlorinated dibenzodioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs). The pattern of geographic variation was consistent over time in eggs with Cootes Paradise/ Hamilton Harbour and Lynde Creek eggs on Lake Ontario containing the highest concentrations and most PCDD and PCDF congeners among all sites. Eggs from Cranberry Marsh on Lake Ontario contained organochlorine concentrations similar to those from Big Creek Marsh and Rondeau Provincial Park on Lake Erie except PCDDs and PCDFs which occurred at higher concentrations and more congeners were detectable in Cranberry Marsh eggs. Concentrations of most contaminants in turtle eggs from Algonquin Park, the reference site, have significantly decreased in the past decade. Dieldrin concentrations, however, increased in Algonquin Park eggs from 1981 to 1989. Significant decreases in concentrations of hexachlorobenzene, mirex and PCBs occurred between turtle eggs collected in 1981/84 and 1989 at Big Creek Marsh and Rondeau Provincial Park, whereas there was no significant change in concentrations of p,p'-DDE and dieldrin. In Lake Ontario eggs, concentrations of PCBs, p,p'-DDE and dieldrin increased significantly between 1984 and 1991. Differences were also found in patterns of temporal variation in contamination between herring gulls (Larus argentatus) and snapping turtles which were attributed to differences in diet. Elevated and continued contamination in turtle eggs from Lake. Ontario is probably due to a combination of local sources of chemicals and consumption of large migratory fish that spawn in wetlands inhabited by these turtles.

Correction of bone marrow nucleated cell counts for the presence of fat particles

Although the use of bone marrow transplantation has increased greatly in recent years, the quality control procedures used in bone marrow processing laboratories remain less than ideal. Accurate marrow total nucleated cell (TNC) counts are essential for effective monitoring of bone marrow collection and processing. Aspirated marrow is variably contaminated by fat particles, resulting in overestimation of marrow TNC by automated analyzers. A recently-marketed hematological analyzer (Cobas-Helios; Roche Diagnostic Systems, Branchburg, NJ) offers the potential to correct marrow TNC counts for fat particles using available software. The authors investigated the accuracy of corrected TNC counts on 21 marrow samples, using a visual chamber count as the reference method. The correction methods studied were software correction, using the Cobas-Helios differential system, and replacement of the sample plasma with saline. Uncorrected automated marrow TNC counts (mean, 28.4 x 10(9)/L) were significantly higher than the visual reference counts (mean, 23.1 x 10(9)/L). Neither the mean corrected automated count (24.3 x 10(9)/L) nor the mean saline replaced count (24.6 x 10(9)/L) differed significantly from the mean visual reference count. For both the corrected automated and saline replaced counts, 20 of the 21 data points (95%) fell within a 95% confidence interval computed for the reference method. The authors conclude that both the corrected automated method, using the Cobas-Helios, and the saline replacement method are acceptable alternatives to the visual chamber count.

Flow-cytochemical differential leukocyte analysis with quantitation of neutrophil left shift. An evaluation of the Cobas-Helios analyzer

The Cobas-Helios (Roche Diagnostic Systems, Inc., Branchburg, NJ) is a new, fully automated hematology analyzer that performs a complete blood count and differential leukocyte count (DLC), classifying leukocytes by flow-cytochemical technology. The DLC component of the Cobas-Helios was evaluated according to the National Committee for Clinical Laboratory Standards H20-A protocol. Instrument performance was acceptable with respect to all parameters investigated, including imprecision, inaccuracy and clinical sensitivity for the identification of quantitative and qualitative leukocyte abnormalities. In a minority of samples with neutrophil left shift, neutrophils tended to overlap the monocyte domain, resulting in overestimation of monocytes and underestimation of neutrophils. This problem did not affect clinical sensitivity and was generally associated with a positive instrumental left-shift flag. Flags for the identification of specific qualitative abnormalities of the leukocyte population (atypical lymphoid cells, nucleated red cells, blast cells, immature granulocytes and neutrophil left shift) performed well. In addition to a conventional five-part DLC, the Cobas-Helios also identifies and quantitates atypical lymphoid cells and "large immature cells," the latter corresponding to bands and immature granulocytes. Counts of atypical lymphoid cells and large immature cells correlated well with the equivalent cell classes as enumerated by the reference method of the National Committee for Clinical Laboratory Standards. The Cobas-Helios offers the most reliable quantitative index of neutrophil left shift currently available in a commercial automated DLC analyzer.

A parallel evaluation of four automated hematology analyzers

A parallel evaluation was performed on four automated hematology analyzers: the Celldyn 3000 (Unipath Corp., Mountain View, CA), the Coulter STKS (Coulter Electronics Inc., Hialeah, FL), the Sysmex NE-8000 (Baxter Healthcare Corp., McGaw Park, IL), and the Technicon H*2 (Miles Corp., Tarrytown, NY). The protocol included evaluation of the complete blood count and differential leukocyte count (DLC) parameters. The DLC evaluation was performed using the National Committee for Clinical Laboratory Studies H20-A protocol. Based on this evaluation, the authors could not identify a single instrument that was clearly superior to the others. Overall, the four instruments were found to be safe and effective for diagnostic use; however, there were areas in which their performance was less than optimal. Particular questions were raised regarding the clinical usefulness of instrumental "flags" to identify qualitative leukocyte abnormalities. The results are discussed in relation to the selection of instruments for specific clinical applications.

The case for a cause-effect linkage between environmental contamination and development in eggs of the common snapping turtle (Chelydra S.serpentina) from Ontario, Canada

Concentrations of polychlorinated biphenyls (PCBs), dibenzo-p-dioxins, and dibenzofurans, organochlorine pesticides, and their metabolites were measured in eggs of the common snapping turtle (Chelydra s.serpentina) collected from four wetlands on the shorelines of Lakes Ontario, and Erie, and one control location in central Ontario, Canada. Snapping turtle eggs from these sites were also artificially incubated to determine hatching success, and incidence of deformities in embryo and hatchling turtles. The hypothesis that elevated incidences of egg death and/or deformities of hatchling turtles would occur in populations with high concentrations of organochlorine contaminants in eggs was tested. The results were elevated using epidemiological criteria. Unhatched eggs and deformities occurred at significantly higher rates in eggs from Lake Ontario wetlands. Two of three sites from Lake Ontario had substantially higher levels of PCBs, dioxins, and furans compared to eggs from Lake Erie and the control site. It could not be shown that contamination of eggs preceded the occurrence of poor development of eggs, although excellent hatching success and low numbers of deformities in eggs from the control site were considered representative of development in healthy eggs. The statistical association between contaminant levels in eggs and poor development of these eggs supported the hypothesis that eggs from sites with the greatest contamination had the highest rates of abnormalities. PCBs were the most strongly associated chemicals, although possible effects due to the presence of other chemicals in eggs was a confounding factor. The deformities and rates of unhatched eggs were similar to those occurring in other vertebrates collected from highly contaminated areas of the Great Lakes. There were several chemicals present in the eggs that can cause similar reproductive effects in other species; therefore a specific chemical effect was not identified. Results were coherent with known statistical and biological information. Theoretical and factual evidence of PCB contamination in wild-caught snapping turtles supported and hypothesis. However, lack of controlled studies of reproductive effects of polychlorinated hydrocarbons upon this species hindered the agreement of all factual and theoretical evidence with the hypothesis.

Peptide cotransmitter potentiates calcium channel activity in crayfish skeletal muscle

The activity of 2 types of Ca2+ channels (38 and 14 pS in 137 mM Ba2+) in the plasma membrane of the crayfish tonic flexor muscle is modulated by the peptide proctolin. This peptide serves as a cotransmitter in 3 of the 5 excitatory tonic flexor motoneurons and greatly enhances tension after depolarization by the conventional neurotransmitter. Proctolin alone has no effect on these channels, but renders them capable of sustained activity following depolarization. After depolarization induces activity, 5 x 10(-9) M proctolin increases the open probability of the larger channel up to 50-fold due to a marked decrease in the mean channel closed time. There is also at least a 4-fold increase in the percentage of patches with active channels for the large channel and a 2-fold increase for the small channel. Proctolin modulation appears to occur via an intracellular messenger, possibly cAMP. The peptide's effect on channel activity is dose dependent in a manner that parallels its effect on tension. These results indicate that the activation of these channels and the resulting influx of Ca2+ into the muscle fiber play a role in the potentiation of tension in this muscle.

Physiological consequences of a peptide cotransmitter in a crayfish nerve-muscle preparation

The pentapeptide proctolin is colocalized with a conventional, conductance-increasing neurotransmitter in 3 of 5 excitatory motoneurons that innervate a posture-related tonic flexor muscle of the crayfish. It is released from these neurons in response to nerve impulses. Nanomolar concentrations of proctolin superfused on the tonic flexor muscle act postsynaptically to potentiate tension generated by a given level of depolarization. Proctolin alone has no detectable effect on muscle tension, nor does it alter the resting membrane potential of the muscle. Proctolin produces no detectable effect on the EPSPs of the 1 proctolinergic motoneuron that was examined. Neurally released proctolin can be selectively depleted from severed motor axons following prolonged, low-frequency stimulation; EPSPs reflecting conventional transmitter release are unaltered by this procedure. After proctolin depletion, tension generated by the motoneuron is greatly reduced. Taken together, these results indicate that the peptide secondary transmitter in this neuromuscular preparation is an important contributor to the magnitude of tension generated by the motoneuron, but since its effect is dependent on the depolarizing EPSPs of the conventional neurotransmitter, it does not contribute to the temporal aspects of tension generation. These aspects are controlled exclusively by the conventional neurotransmitter.

Mapping of proctolinlike immunoreactivity in the nervous systems of lobster and crayfish

Whole-mount immunocytochemical techniques have been used to map candidate proctolin-containing cells in the central nervous systems of the lobster, Homarus americanus, and the crayfish, Procambarus clarkii. Proctolinlike immunoreactivity was detected in cell bodies and neuropil regions in all central ganglia, and immunoreactive axons were detected in most interganglionic connectives and nerve roots. Cell body staining was confined to fewer than 2% of all cells. Immunoreactive neurons include motoneurons, sensory neurons, neurosecretory cells, and interneurons. Colocalization of the proctolinlike antigen with other neurotransmitters was indicated in a number of cases. Many aspects of the distribution of immunoreactivity were similar in lobster and crayfish; however, staining differences were detected in a number of identified neurons and neural groups, including neurons that innervate the pericardial organs and hindgut motoneurons. Further studies of such neurons might provide interesting clues about the physiological functions of proctolin and the evolution of peptide transmission.

Neuropeptide proctolin in postural motoneurons of the crayfish

The neuropeptide transmitter candidate proctolin (H-Arg-Tyr-Leu-Pro-Thr-OH) was associated with three of the five excitatory motoneurons innervating the tonic flexor muscles of the crayfish abdomen. Proctolin immunohistochemical staining occurred in cell bodies and axons of these three identified neurons. Stained axon terminals were detected across the entire tonic flexor muscle. Bioassay of extracts of the tonic flexor muscles indicated the presence of 370 fmol of proctolin/muscle or 670 fmol/mg dry weight. Bioactivity was eliminated in muscles in which the tonic flexor motor root was cut 2 months prior to extraction and in muscle extracts pre-incubated with proctolin antiserum. High pressure liquid chromatography purification of tissue extract indicated that all bioactivity in the crude extract was due to authentic proctolin. Our findings suggest that these three cells function as peptidergic motoneurons. A precedent for this is the proctolin-containing postural motoneuron of the cockroach.

Serotonin immunoreactive neurons in the central nervous system of an insect (Periplaneta americana)

Serotonin-like immunoreactivity was mapped in the central nervous system (CNS) of the cockroach, Periplaneta americana. Immunoreactive staining occurred in every ganglion of the CNS. The largest numbers of immunoreactive somata were detected in the optic lobes and the brain, and lowest numbers in the first and second thoracic ganglia. Dense stained fibers, ramifications, and varicosities were found in all ganglia, and numerous axon like processes occurred in all interganglionic connectives. Immunoreactive processes were not, however, detected in most of the peripherally projecting nerve roots. Processes were found only in roots of the suboesophageal ganglion and the tritocerebral lobes of the brain. A comparison of the map for serotonin immunoreactivity with one generated for the pentapeptide transmitter proctolin suggests that the two systems overlap only in the suboesophageal ganglion and the tritocerebrum. The amine and peptide may co-occur in neurons in these regions. The serotonin immunoreactive system appeared significantly different from the octopaminergic system of the ventral nerve cord. Seventy-two potentially identifiable immunoreactive cells were located in the cockroach CNS. Some of these may be suitable for physiological study of the functional role of serotonin.

Identification of proctolin-containing neurons

Proctolin (H-Arg-Tyr-Leu-Pro-Thr-OH), a highly bioactive peptide found first in insects, is shown to be localized to specific neurons in the central nervous system (CNS) of the cockroach Periplaneta americana. Application of an antiproctolin serum to whole ganglia in a whole-mount immunohistochemical technique reveals the presence of proctolin immunoreactive neurons throughout the CNS. These neurons can be mapped and appear in consistent positions in different individuals. Some have been uniquely identified by intracellular dye injection combined with immunological localization. The presence of proctolin in individually identified neurons has been determined by high-pressure liquid chromatography combined with proctolin bioassay detection performed on extracts made from single identified cells. Some proctolin-containing neurons contain large vacuolelike inclusions in their cell bodies. These vacuoles appear to be the greatly enlarged lumena of the rough endoplasmic reticulum and may be part of the morphological substrate for the manufacture of proctolin. Electrophysiological studies suggest that some proctolin-containing neurons in different segmental ganglia, although not all, are normally recruited together as a functional unit by shared presynaptic input. This characterization of individual proctolin neurons is a prelude to a cellular study of the physiological role of a neuropeptide.

Neuropeptide proctolin associated with an identified skeletal motoneuron

Our objective was to find large and identifiable peptide-containing neurons and their postsynaptic targets. For this, a whole mount immunohistochemical method was used to locate cell bodies of neurons in the cockroach central nervous system immunoreactive to antibodies raised against the pentapeptide proctolin (H-Arg-Tyr-Leu-Pro-Thr-OH). The morphology and projections of the immunoreactive neurons were investigated by combining intracellular dye injection and electrophysiological and immunochemical procedures. The presence of proctolin in specific immunoreactive neurons was check by high pressure liquid chromatography combined with bioassay applied to extracts made from individually identified and isolated cell bodies. Using these approaches, we have identified a large proctolin-containing motoneuron which innervates muscles in a proximal segment of the cockroach leg. This study establishes a well characterized cellular preparation in which the physiological actions and functions of a peptide-containing neuron can be studied in vivo.

Neuropeptide proctolin (H-Arg-Try-Leu-Pro-Thr-OH): immunocytochemical mapping of neurons in the central nervous system of the cockroach

Proctolinlike immunoreactivity was mapped in the central nervous system of the cockroach, Periplaneta americana, by using whole-ganglion immunoreacted preparations. The procedure for this immunohistochemical staining of whole-mounts is described. Immunoreactivity was confined to neuronal cell bodies and and processes. These were found in all ganglia of the CNS. The cells varied in the consistency and intensity of their staining. The occurrence and variability of staining is described in detail. Cell bodies were found in the dorsal, ventral, and lateral regions of the ganglia. The highest number of cell bodies was found in the terminal ganglion and the lowest number in the cerebral ganglion. Those in the cerebral ganglion occurred mainly in the tritocerebral lobes. The distribution of immunoreactive cell bodies correlated with results previously obtained by radioimmunoassay. Immunoreactive processes were detected in all interganglionic connectives and many ganglionic nerve roots. Dense ramifications of immunoreactive processes and variocosities were detected in many of the ganglia. The widespread presence of immunoreactivity suggests that proctolin has diverse central and peripheral functions. The mapping immunoreactive neuronal somata provides a valuable step in the identification of putative proctolin-containing neurons suitable for further biochemical, anatomical, and physiological analysis.

Infectious gastroenteritis in bone-marrow-transplant recipients

We prospectively evaluated infections with several gastrointestinal pathogens in patients undergoing bone-marrow transplantation, in an attempt to correlate infection with morbidity and mortality. Thirty-one of 78 patients (40 per cent) were infected with one or more of the following enteric pathogens during the study: adenovirus (12 infections), rotavirus (nine), coxsackievirus (four), or Clostridium difficile (12). Several patients were infected with more than one pathogen. Infection correlated with the occurrence of diarrhea and abdominal cramps. The mortality rate among the infected patients was 55 per cent--significantly higher than the rate (13 per cent) among the noninfected patients (P less than 0.001). This study indicates that enteric pathogens that often cause mild diarrhea in normal populations can cause serious infections in marrow-transplant recipients. Measures aimed at preventing or treating such infections might reduce the morbidity and mortality associated with marrow transplantation.

Outbreak of Coxsackie A1 gastroenteritis: a complication of bone-marrow transplantation

In a three-week period 7 of 14 transplant recipients were infected with coxsackie A1 virus. Diarrhoea and mortality were significantly associated with infection (7 of 7 infected compared with 0 of 7 non-infected, and 6 of 7 infected compared with 1 of 7 non-infected, respectively). Early in the outbreak, the diarrhoea was presumed to be due to acute graft-versus-host disease (AGVHD). However, the distribution of AGVHD among infected and non-infected patients was nearly equal, and at necropsy 3 of 6 infected patients who had had diarrhoea showed no evidence of gastrointestinal involvement with AGVHD. Infection with viral enteric pathogens may be an important factor in the clinical course of transplant recipients.

Neuropeptide proctolin (H-Arg-Tyr-Leu-Pro-Thr-OH): immunological detection and neuronal localization in insect central nervous system

Proctolin (H-Arg-Tyr-Leu-Pro-Thr-OH) is a pentapeptide first extracted from cockroaches. It is known to have many neurohormonal effects and has been associated with specific, identified cockroach neurons. We have produced proctolin antisera and report here on their application in detecting proctolin-like immunoreactivity (PLI) in the cockroach central nervous system. Radioimmunoassay, capable of detectable 50 fmol of proctolin, was used to quantify the distribution of PLI. Highest concentrations were detected in the genital ganglia and lowest in the cerebral ganglia. Immunohistochemistry on the cockroach central nervous system demonstrated that PLI is localized to neurons. Neurons stained by using immunohistochemistry were widespread in the ganglia. Cell bodies were found to be in constant positions from animal to animal and to occur in bilaterally symmetrical pairs. These neurons are potentially identifiable.

Use of perfluoroalkanoic acids as volatile ion pairing reagents in preparative HPLC

This report describes the successful use of the ether soluble, ion pairing reagents perfluoropropoinic and perfluorobutyric acid in the preparative and analytical reserved phase HPLC of underivatised peptides. The preparative separation of a 1-g sample of Pyr-His-Gly, the proposed anorexigenic peptide, is described on C18-silica which was packed in a flexible-walled cartridge and subjected to radial compression. The mobile phase consisted of an aqueous solution of perfluorobutyric acid (5 mM) and a flow rate of 100 ml/min was used. The purified peptide was simply isolated by neutralizing and freeze-drying the corresponding peak and then extracting the excess ion pairing reagent with ether. The product was then shown to be homogeneous by analytical HPLC and amino acid analysis. The tripeptide failed to show any effect on food intake, water intake or body weight in female rats. Similarly no effect was noted on the reproductive cycles of the rat.

Vertical motion detectors and their synaptic relations in the third optic lobe of the fly

The synaptic relations of the giant vertical cells in the lobula plate of the fly were investigated using electron microscopical procedures and Lucifer yellow dye backfill and injection techniques. Histological features of the giant vertical cells are described. The giant vertical cells are exclusively postsynaptic in the lobula plate. They function to integrate input from dense arrays of chemical synapses and have a wide spatial input from the lobula plate. The giant vertical cells are postsynaptic to perpendicularly occurring cells. There are two classes of cells presynaptic to the vertical cells, one of which contains large dense-core vesicles. The giant vertical cells are not the only cells postsynaptic to these two classes of perpendicular cells. A second group of smaller tangential cells, the twin vertical cells, were also found postsynaptic to many of the same cells that synapsed with the giant vertical cells. The twin vertical cells and the giant vertical cells are therefore integrating some of the same information in the lobula plate.

Separation of the apoprotein components of human very low density lipoproteins by ion-paired, reversed-phase high performance liquid chromatography

A number of crude apolipoprotein samples isolated from human very low density lipoproteins (VLDL) were analyzed by reversed phase high performance liquid chromatography. The mobile phase consisted of a 1% solution of the polar ion-pairing reagent triethylammonium phosphate. A slow, nonlinear gradient of acetonitrile (37--42%) was used to elute the apolipoproteins. The order of elution was as follows: apolipoprotein CX, apolipoprotein C-I, apolipoprotein C-III2, apolipoprotein C-III1, apolipoprotein C-IIIQ and apolipoprotein C-II. This order is consistent with the known polarity of the proteins, i.e., the most nonpolar, apolipoprotein C-II, was the last to be eluted, whereas apolipoprotein C-I, with the lowest nonpolar surface area eluted first. The recovery of the individual apolipoproteins was 80--95% and the individual peaks were characterized by amino acid analysis, UV absorption spectra amd chromatography of pure protein standards.

High-pressure liquid chromatography of amino acids, peptides and proteins. V. Separation of thyroidal iodo-amino acids by hydrophilic ion-paired reversed-phase high-performance liquid chromatography

The separation of thyroidal iodoamino acids has been carried out by high-performance liquid chromatography in phase systems consisting of chemically bonded C18-hydrophobic supports as the stationary phase and water-organic solvent mixtures containing phosphoric acid or other ion-pairing reagents as the mobile phase. Under conditions of hydrophilic ion-pair formation, excellent resolution of the iodoamino acids is observed. This method permits the rapid separation and, hence, analysis of mixtures containing thyroxine, 3,3',5-triiodothyronine and 3,3',5'-triiodothyronine and related compounds in ca. 30 min with sensitivity, using a UV monitor at 210 nm, at the 1-10-pmole level.