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peer-reviewed The full text of this article will not be available in ULIR until the embargo expires on the 31/01/2020 The aim of this study was to investigate the properties and to functionally characterize the cervical mucus that modulates sperm transport through the cervix by using ewe breeds with a divergent pregnancy rate (Belclare and Suffolk; high and low, respectively) following cervical insemination using frozen-thawed semen. Sperm number, as well as sialic acid and fricose content in both the channels and in the lumen of different regions of the cervix were quantified in inseminated Belclare and Suffolk ewes. Expression of glycosyltransferase and MUC genes, glycosidase activity and sialic acid speciation in follicular phase cervical tissue and mucus were assessed. More spermatozoa were found in the cervical channels in the region dosest to the cervical os in Belclare than Suffolk ewes (P< 0.05) and Suffolk ewes had a higher sialic acid content in the cervical channels than Belclare ewes (P < 0.05) in all regions of cervix. Suffolk ewes had significantly higher expression of FUT1, ST6GAL1 and MUC5AC than Belclare ewes. There was no difference between the breeds in glycosidase activity (P> 0.05). Levels of Neu5Ac were higher in Belclare than Suffolk ewes (P < 0.05) and levels of Neu5Gc was higher in Suffolk than Belclare ewes (P < 0.05). Competitive sperm penetration assays demonstrated that frozen-thawed sperm progression increased when cervical mucus was incubated with sialyllactose prior to a sperm penetration test (P < 0.05). These results suggest that the difference between Belclare and Suffolk ewes in sperm transport with frozen-thawed semen is due to the higher concentration of sialic acid within channels, which binds to spermatozoa and reduces their ability to traverse the cervix. peer-reviewed

Autism spectrum disorder (ASD) and obsessive-compulsive disorder (OCD) often share phenotypes of repetitive behaviors, possibly underpinned by abnormal decision-making. To compare neural correlates underlying decision-making between these disorders, brain activation of boys with ASD (N = 24), OCD (N = 20) and typically developing controls (N = 20) during gambling was compared, and computational modeling compared performance. Patients were unimpaired on number of risky decisions, but modeling showed that both patient groups had lower choice consistency and relied less on reinforcement learning compared to controls. ASD individuals had disorder-specific choice perseverance abnormalities compared to OCD individuals. Neurofunctionally, ASD and OCD boys shared dorsolateral/inferior frontal underactivation compared to controls during decision-making. During outcome anticipation, patients shared underactivation compared to controls in lateral inferior/orbitofrontal cortex and ventral striatum. During reward receipt, ASD boys had disorder-specific enhanced activation in inferior frontal/insular regions relative to OCD boys and controls. Results showed that ASD and OCD individuals shared decision-making strategies that differed from controls to achieve comparable performance to controls. Patients showed shared abnormalities in lateral-(orbito)fronto-striatal reward circuitry, but ASD boys had disorder-specific lateral inferior frontal/insular overactivation, suggesting that shared and disorder-specific mechanisms underpin decision-making in these disorders. Findings provide evidence for shared neurobiological substrates that could serve as possible future biomarkers.

Neuroimaging studies have reported structural and physiological differences that could help understand the causes and development of Autism Spectrum Disorder (ASD). Many of them rely on multisite designs, with the recruitment of larger samples increasing statistical power. However, recent large-scale studies have put some findings into question, considering the results to be strongly dependent on the database used, and demonstrating the substantial heterogeneity within this clinically defined category. One major source of variance may be the acquisition of the data in multiple centres. In this work we analysed the differences found in the multisite, multi-modal neuroimaging database from the UK Medical Research Council Autism Imaging Multicentre Study (MRC AIMS) in terms of both diagnosis and acquisition sites. Since the dissimilarities between sites were higher than between diagnostic groups, we developed a technique called Significance Weighted Principal Component Analysis (SWPCA) to reduce the undesired intensity variance due to acquisition site and to increase the statistical power in detecting group differences. After eliminating site-related variance, statistically significant group differences were found, including Broca's area and the temporo-parietal junction. However, discriminative power was not sufficient to classify diagnostic groups, yielding accuracies results close to random. Our work supports recent claims that ASD is a highly heterogeneous condition that is difficult to globally characterize by neuroimaging, and therefore different (and more homogenous) subgroups should be defined to obtain a deeper understanding of ASD. Hum Brain Mapp 38:1208–1223, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc. 38 3 1208 1223 Export Date: 17 July 2017

It has been postulated that autism spectrum disorder is underpinned by an 'atypical connectivity' involving higher-order association brain regions. To test this hypothesis in a large cohort of adults with autism spectrum disorder we compared the white matter networks of 61 adult males with autism spectrum disorder and 61 neurotypical controls, using two complementary approaches to diffusion tensor magnetic resonance imaging. First, we applied tract-based spatial statistics, a 'whole brain' non-hypothesis driven method, to identify differences in white matter networks in adults with autism spectrum disorder. Following this we used a tract-specific analysis, based on tractography, to carry out a more detailed analysis of individual tracts identified by tract-based spatial statistics. Finally, within the autism spectrum disorder group, we studied the relationship between diffusion measures and autistic symptom severity. Tract-based spatial statistics revealed that autism spectrum disorder was associated with significantly reduced fractional anisotropy in regions that included frontal lobe pathways. Tractography analysis of these specific pathways showed increased mean and perpendicular diffusivity, and reduced number of streamlines in the anterior and long segments of the arcuate fasciculus, cingulum and uncinate - predominantly in the left hemisphere. Abnormalities were also evident in the anterior portions of the corpus callosum connecting left and right frontal lobes. The degree of microstructural alteration of the arcuate and uncinate fasciculi was associated with severity of symptoms in language and social reciprocity in childhood. Our results indicated that autism spectrum disorder is a developmental condition associated with abnormal connectivity of the frontal lobes. Furthermore our findings showed that male adults with autism spectrum disorder have regional differences in brain anatomy, which correlate with specific aspects of autistic symptoms. Overall these results suggest that autism spectrum disorder is a condition linked to aberrant developmental trajectories of the frontal networks that persist in adult life. © 2016 The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. 139 2 616 630 Cited By :7; Export Date: 17 July 2017

Autism spectrum disorders (ASD) are a group of neurodevelopmental conditions characterized by atypical structural and functional brain connectivity. Complex network analysis has been mainly used to describe altered network-level organization for functional systems and white matter tracts in ASD. However, atypical functional and structural connectivity are likely to be also linked to abnormal development of the correlated structure of cortical gray matter. Such covariations of gray matter are particularly well suited to the investigation of the complex cortical pathology of ASD, which is not confined to isolated brain regions but instead acts at the systems level. In this study, we examined network centrality properties of gray matter networks in adults with ASD (n = 84) and neurotypical controls (n = 84) using graph theoretical analysis. We derived a structural covariance network for each group using interregional correlation matrices of cortical volumes extracted from a surface-based parcellation scheme containing 68 cortical regions. Differences between groups in closeness network centrality measures were evaluated using permutation testing. We identified several brain regions in the medial frontal, parietal and temporo-occipital cortices with reductions in closeness centrality in ASD compared to controls. We also found an association between an increased number of autistic traits and reduced centrality of visual nodes in neurotypicals. Our study shows that ASD are accompanied by atypical organization of structural covariance networks by means of a decreased centrality of regions relevant for social and sensorimotor processing. These findings provide further evidence for the altered network-level connectivity model of ASD. © 2015 Elsevier Ltd. 69 142 149 Cited By :2; Export Date: 17 July 2017

Autism spectrum disorders (ASD) are a group of conditions that show abnormalities in the neuroanatomy of multiple brain regions. The variability in the development of intelligence and language among individuals on the autism spectrum has long been acknowledged, but it remains unknown whether these differences impact on the neuropathology of ASD. In this study, we aimed to compare associations between surface-based regional brain measures and general intelligence (IQ) scores in ASD individuals with and without a history of language delay. We included 64 ASD adults of normal intelligence (37 without a history of language delay and 27 with a history of language delay and 80 neurotypicals). Regions with a significant association between verbal and nonverbal IQ and measures of cortical thickness (CT), surface area, and cortical volume were first identified in the combined sample of individuals with ASD and controls. Thicker dorsal frontal and temporal cortices, and thinner lateral orbital frontal and parieto-occipital cortices were associated with greater and lower verbal IQ scores, respectively. Correlations between cortical volume and verbal IQ were observed in similar regions as revealed by the CT analysis. A significant difference between ASD individuals with and without a history of language delay in the association between CT and verbal IQ was evident in the parieto-occipital region. These results indicate that ASD subgroups defined on the basis of differential language trajectories in childhood can have different associations between verbal IQ and brain measures in adulthood despite achieving similar levels of cognitive performance. © 2015 International Society for Autism Research, Wiley Periodicals, Inc. 8 5 556 566 Cited By :2; Export Date: 17 July 2017

Little is known about the symptom profile of obsessive-compulsive disorder (OCD) in individuals who have autism spectrum disorders (ASD). It is also unknown whether self-report questionnaires are useful in measuring OCD in ASD. We sought to describe the symptom profiles of adults with ASD, OCD, and ASD + OCD using the Obsessive Compulsive Inventory-Revised (OCI-R), and to assess the utility of the OCI-R as a screening measure in a high-functioning adult ASD sample. Individuals with ASD (n = 171), OCD (n = 108), ASD + OCD (n = 54) and control participants (n = 92) completed the OCI-R. Individuals with ASD + OCD reported significantly higher levels of obsessive-compulsive symptoms than those with ASD alone. OCD symptoms were not significantly correlated with core ASD repetitive behaviors as measured on the ADI-R or ADOS-G. The OCI-R showed good psychometric properties and corresponded well with clinician diagnosis of OCD. Receiver operating characteristic analysis suggested cut-offs for OCI-R Total and Checking scores that discriminated well between ASD + versus –OCD, and fairly well between ASD-alone and OCD-alone. OCD manifests separately from ASD and is characterized by a different profile of repetitive thoughts and behaviors. The OCI-R appears to be useful as a screening tool in the ASD adult population.

Little is known about the symptom profile of obsessive-compulsive disorder (OCD) in individuals who have autism spectrum disorders (ASD). It is also unknown whether self-report questionnaires are useful in measuring OCD in ASD. We sought to describe the symptom profiles of adults with ASD, OCD, and ASD+OCD using the Obsessive Compulsive Inventory-Revised (OCI-R), and to assess the utility of the OCI-R as a screening measure in a high-functioning adult ASD sample. Individuals with ASD (n=171), OCD (n=108), ASD+OCD (n=54) and control participants (n=92) completed the OCI-R. Individuals with ASD+OCD reported significantly higher levels of obsessive-compulsive symptoms than those with ASD alone. OCD symptoms were not significantly correlated with core ASD repetitive behaviors as measured on the ADI-R or ADOS-G. The OCI-R showed good psychometric properties and corresponded well with clinician diagnosis of OCD. Receiver operating characteristic analysis suggested cut-offs for OCI-R Total and Checking scores that discriminated well between ASD+versus -OCD, and fairly well between ASD-alone and OCD-alone. OCD manifests separately from ASD and is characterized by a different profile of repetitive thoughts and behaviors. The OCI-R appears to be useful as a screening tool in the ASD adult population. © 2015 International Society for Autism Research, Wiley Periodicals, Inc. 8 5 477 485 Cited By :9; Export Date: 17 July 2017

BackgroundIncreasing evidence suggests that autism is associated with abnormal white-matter (WM) anatomy and impaired brain ‘connectivity’. While myelin plays a critical role in synchronized brain communication, its aetiological role in autistic symptoms has only been indirectly addressed by WM volumetric, relaxometry and diffusion tensor imaging studies. A potentially more specific measure of myelin content, termed myelin water fraction (MWF), could provide improved sensitivity to myelin alteration in autism.MethodWe performed a cross-sectional imaging study that compared 14 individuals with autism and 14 age- and IQ-matched controls. T1 relaxation times (T1), T2 relaxation times (T2) and MWF values were compared between autistic subjects, diagnosed using the Autism Diagnostic Interview – Revised (ADI-R), with current symptoms assessed using the Autism Diagnostic Observation Schedule (ADOS) and typical healthy controls. Correlations between T1, T2 and MWF values with clinical measures [ADI-R, ADOS, and the Autism Quotient (AQ)] were also assessed.ResultsIndividuals with autism showed widespread WM T1 and MWF differences compared to typical controls. Within autistic individuals, worse current social interaction skill as measured by the ADOS was related to reduced MWF although not T1. No significant differences or correlations with symptoms were observed with respect to T2.ConclusionsAutistic individuals have significantly lower global MWF and higher T1, suggesting widespread alteration in tissue microstructure and biochemistry. Areas of difference, including thalamic projections, cerebellum and cingulum, have previously been implicated in the disorder; however, this is the first study to specifically indicate myelin alteration in these regions.

Objective: Sustained attention problems are common in people with autism spectrum disorder (ASD) and may have significant implications for the diagnosis and management of ASD and associated comorbidities. Furthermore, ASD has been associated with atypical structural brain development. The authors used functional MRI to investigate the functional brain maturation of attention between childhood and adulthood in people with ASD. Method: Using a parametrically modulated sustained attention/vigilance task, the authors examined brain activation and its linear correlation with age between childhood and adulthood in 46 healthy male adolescents and adults (ages 11-35 years) with ASD and 44 age- and IQ-matched typically developing comparison subjects. Results: Relative to the comparison group, the ASD group had significantly poorer task performance and significantly lower activation in inferior prefrontal cortical, medial prefrontal cortical, striato-thalamic, and lateral cerebellar regions. A conjunction analysis of this analysis with group differences in brain-age correlations showed that the comparison group, but not the ASD group, had significantly progressively increased activation with age in these regions between childhood and adulthood, suggesting abnormal functional brain maturation in ASD. Several regions that showed both abnormal activation and functional maturation were associated with poorer task performance and clinical measures of ASD and inattention. Conclusions: The results provide first evidence that abnormalities in sustained attention networks in individuals with ASD are associated with underlying abnormalities in the functional brain maturation of these networks between late childhood and adulthood. © 2014, American Psychiatric Association. All rights reserved. 171 10 1107 1116 Cited By :10; Export Date: 17 July 2017

Autism spectrum disorders (ASD) are a group of neurodevelopmental conditions that are accompanied by atypical brain connectivity. So far, in vivo evidence for atypical structural brain connectivity in ASD has mainly been based on neuroimaging studies of cortical white matter. However, genetic studies suggest that abnormal connectivity in ASD may also affect neural connections within the cortical gray matter. Such intrinsic gray-matter connections are inherently more difficult to describe in vivo but may be inferred from a variety of surface-based geometric features that can be measured using magnetic resonance imaging. Here, we present a neuroimaging study that examines the intrinsic cortico-cortical connectivity of the brain in ASD using measures of “cortical separation distances” to assess the global and local intrinsic “wiring costs” of the cortex (i.e., estimated length of horizontal connections required to wire the cortex within the cortical sheet). In a sample of 68 adults with ASD and matched controls, we observed significantly reduced intrinsic wiring costs of cortex in ASD, both globally and locally. Differences in global and local wiring cost were predominantly observed in fronto-temporal regions and also significantly predicted the severity of social and repetitive symptoms (respectively). Our study confirms that atypical cortico-cortical “connectivity” in ASD is not restricted to the development of white-matter connections but may also affect the intrinsic gray-matter architecture (and connectivity) within the cortical sheet. Thus, the atypical connectivity of the brain in ASD is complex, affecting both gray and white matter, and forms part of the core neural substrates underlying autistic symptoms.

Antisocial personality disorder (ASPD) and psychopathy involve significant interpersonal and behavioural impairments. However, little is known about their underlying neurobiology and in particular, abnormalities in white matter (WM) microstructure. Apreliminary diffusion tensor magnetic resonance imaging (DT-MRI) study of adult psychopaths employing tractography revealed abnormalities in the right uncinate fasciculus (UF) (Craig et al., 2009), indicating fronto-limbic disconnectivity. However, it is not clear whether WM abnormalities are restricted to this tract or are or more widespread, including other tracts which are involved in connectivity with the frontal lobe.We performed whole brain voxel-based analyses on WM fractional anisotropy (FA) and mean diffusivity (MD) maps acquired with DT-MRI to compare 15 adults with ASPD and healthy age, handedness and IQ-matched controls. Also, within ASPD subjects we related differences in FA and MD to measures of psychopathy.Significant WM FA reduction and MD increases were found respectively in ASPD subjects relative to controls. FA was bilaterally reduced in the genu of corpus callosum while in the right frontal lobe FA reduction was found in the UF, inferior fronto-occipital fasciculus (IFOF), anterior corona radiata and anterior limb and genu of the internal capsule. These differences negatively correlated with measures of psychopathy. Also in the right frontal lobe, increased MD was found in the IFOF and UF, and the corpus callosum and anterior corona radiata. There was a significant positive correlation between MD and psychopathy scores. Conclusions: The present study confirms a previous report of reduced FA in the UF. Additionally, we report for the first time, FA deficits in tracts involved in interhemispheric as well as frontal lobe connectivity in conjunction with MD increases in the frontal lobe. Hence, we provide evidence of significant WM microstructural abnormalities in frontal brain regions in ASPD and psychopathy. © 2011 Elsevier Srl. 48 2 216 229 Cited By :51; Export Date: 17 July 2017

Individual differences in cognitive style can be characterized along two dimensions: ‘systemizing’ (S, the drive to analyze or build ‘rule-based’ systems) and ‘empathizing’ (E, the drive to identify another's mental state and respond to this with an appropriate emotion). Discrepancies between these two dimensions in one direction (S > E) or the other (E > S) are associated with sex differences in cognition: on average more males show an S > E cognitive style, while on average more females show an E > S profile. The neurobiological basis of these different profiles remains unknown. Since individuals may be typical or atypical for their sex, it is important to move away from the study of sex differences and towards the study of differences in cognitive style. Using structural magnetic resonance imaging we examined how neuroanatomy varies as a function of the discrepancy between E and S in 88 adult males from the general population. Selecting just males allows us to study discrepant E-S profiles in a pure way, unconfounded by other factors related to sex and gender. An increasing S > E profile was associated with increased gray matter volume in cingulate and dorsal medial prefrontal areas which have been implicated in processes related to cognitive control, monitoring, error detection, and probabilistic inference. An increasing E > S profile was associated with larger hypothalamic and ventral basal ganglia regions which have been implicated in neuroendocrine control, motivation and reward. These results suggest an underlying neuroanatomical basis linked to the discrepancy between these two important dimensions of individual differences in cognitive style., Highlights ► Empathizing (E)–Systemizing (S) discrepancy differentiates human cognitive styles. ► We investigate the brain structural basis for ‘E–S discrepancy’ in adult males. ► S > E profile is related to larger cingulate and dorsal medial prefrontal structures. ► E > S profile is related to larger hypothalamus and ventral basal ganglia. ► E–S discrepancy is reflected by distinct individual differences in brain structure.

Although many examples exist for shared neural representations of self and other, it is unknown how such shared representations interact with the rest of the brain. Furthermore, do high-level inference-based shared mentalizing representations interact with lower level embodied/simulation-based shared representations? We used functional neuroimaging (fMRI) and a functional connectivity approach to assess these questions during high-level inference-based mentalizing. Shared mentalizing representations in ventromedial prefrontal cortex, posterior cingulate/precuneus, and temporo-parietal junction (TPJ) all exhibited identical functional connectivity patterns during mentalizing of both self and other. Connectivity patterns were distributed across low-level embodied neural systems such as the frontal operculum/ventral premotor cortex, the anterior insula, the primary sensorimotor cortex, and the presupplementary motor area. These results demonstrate that identical neural circuits are implementing processes involved in mentalizing of both self and other and that the nature of such processes may be the integration of low-level embodied processes within higher level inference-based mentalizing. ■ © 2009 Massachusetts Institute of Technology. 22 7 1623 1635 Cited By :135; Export Date: 17 July 2017

A novel method of enzyme immobilization using a low molecular weight prepolymer of tri-functional aziridines which can immobilize enzymes both by covalent attachment and entrapment within a gel matrix is described. The enzymes are immobilized on a solid support and exhibit an excellent retention of enzymatic activity. The immobilization procedure is essentially a single step process which can be easily performed at room temperature or 4°C in either aqueous solution or in an inert organic solvent. The polyaziridines used in the immobilization are nontoxic, available in bulk at low cost and completely miscible with water and many organic solvents, thus providing one of the most satisfactory methods of immobilization available.

The male bias in autism spectrum conditions (ASC) has led to females with ASC being under-researched. This lack of attention to females could hide variability due to sex that may explain some of the heterogeneity within ASC. In this study we investigate four key cognitive domains (mentalizing and emotion perception, executive function, perceptual attention to detail, and motor function) in ASC, to test for similarities and differences between males and females with and without ASC (n = 128 adults; n = 32 per group). In the mentalizing and facial emotion perception domain, males and females with ASC showed similar deficits compared to neurotypical controls. However, in attention to detail and dexterity involving executive function, although males with ASC showed poorer performance relative to neurotypical males, females with ASC performed comparably to neurotypical females. We conclude that performance in the social-cognitive domain is equally impaired in male and female adults with ASC. However, in specific non-social cognitive domains, performance within ASC depends on sex. This suggests that in specific domains, cognitive profiles in ASC are modulated by sex. © 2012 Lai et al. 7 10 Cited By :57; Export Date: 17 July 2017

A lethal toxin from the fishing tentacles of the sea nettle, Chrysaora quinquecirrha, affected ion permeability in black lipid membranes by producing monovalent cation channels. These channels appeared to measure approximately 31 pS.

The mature avian erythrocyte provides a favorable model for studies relating nuclear structure, function, and composition. Phosphoproteins have been recognized among nuclear constituents, although no detailed functions have been described for them. Earlier studies of avian erythrocytes may have included plasma membrane phosphoproteins in the nuclear fraction. Plasma membrane and nuclear nonhistone proteins from chicken erythrocytes have been separately isolated and characterized with respect to total phosphorus and [ 32 P]phosphate incorporation. The nuclear nonhistone proteins were 11.7-fold richer in total phosphorus, but phosphorus reached a 2.3-fold higher specific radioactivity in the plasma membrane proteins during a 3-h incubation. Both fractions yielded radioactive phosphoamino acids after acid hydrolysis. The proteins were separated by electrophoresis on 4–30% gradient polyacrylamide gels in the presence of sodium dodecyl sulphate. A 92-kilodalton, plasma membrane-specific protein was the most radioactive constituent. Six to seven phosphoprotein bands were apparent from both the plasma membrane and the nuclear fractions and three bands appeared to be common to both. The circulating erythrocyte maintains its structural integrity without benefit of macromolecular synthesis for an extended period. The protein-bound phosphorus and the continued phosphorylation described herein may reflect activities devoted to the maintenance of structure.

A lethal toxic fraction from nematocysts of the sea nettle (Chrysaora quinquecirrha) fishing tentacle was partially purified by immunochromatography using an immobilized monoclonal antibody column. Elution from the immunosorbent was accomplished under mild conditions which conserved the biological activity of the toxin. The isolated fraction, which contained two purified protein bands with molecular weights of 100,000 and 190,000 daltons on SDS polyacrylamide gels, was both cardiotoxic and neurotoxic and exhibited an intravenous lethal activity (LD50) of 0.37 microgram/g in mice.

A. J. Russo , C. S. Cobbs , G. J. Calton and J. W. Burnett . Detection of common antigenic sites in lethal proteins of non-related animal venoms. Toxicon21, 433–437, 1983. — Monoclonal antibodies neutralizing specific coelenterate lethal toxins were used to determine the presence of homologous antigenic sites on toxin proteins of a rattlesnake (Crotalus durissus terrificus), a hornet (Vespa orientalis) and the sea wasp (Chironex fleckeri). An anti-Portuguese man-o'war toxin antibody was found useful for isolating a C. d. terrificus toxin.

1. Sea nettle nematocyst venom contains hemagglutinins specific for human and rabbit erythrocytcs. 2. These hemagglutinins exist as multiple molecular forms based on their behavior on DEAE cellulose and SDS-PAGE. 3. Hemagglutinin activity was not inhibited by several simple mono- and disaccharides, but was inhibited by dextran sulfate and certain complex polysaccharides.

We have investigated the structure of parental DNA as a function of the cell cycle phase of HeLa cells. DNA was isolated from synchronized HeLa cells 0, 5, 8, and 12 h after release from a second exposure to 2 mM thymidine. These DNA preparations were characterized by CS2SO4/AgClO4 buoyant density, sensitivity to a single-strand specific nuclease, sedimentation in neutral and alkaline sucrose gradients, and sedimentation in neutral sucrose gradients after digestion with S1 nuclease. The cultures were staged according to cell cycle phase by measurements of DNA content per cell by flow microfluorometry. The cell cycle phases were G1/S (0-h culture), S (5-h culture), G2 (8-h culture), and G1 (12-h culture). There are no nuclease-sensitive sites in G2. As the cells enter G1, the number increases, with a maximum being reached in the S phase. The number of breaks in DNA with respect to cell cycle phase follows the same pattern. The amount of single strandedness, measured by buoyant density and nuclease sensitivity, is also minimal in G2, increases in G1, with a maximum achieved in the S phase. It appears that there is a chromosomal cycle, reflected as continuous structural changes in the DNA molecule, as cells traverse the cell cycle.

Monoclonal antibody directed against a lethal factor (PLF) of Portuguese man-o'war ( Physalia physalis ) nematocyst venom cross-reacted with a component of oriental hornet ( Vespa orientalis ) venom in an ELISA. Using immobilized PLF monoclonal antibody, a protein fraction was eluted which was lethal to mice. This fraction (VOLF) contains a major component of molecular weight about 43,000, in addition to several minor components.

The case histories of three patients with unusual reactions to jellyfish envenomations or increased amounts of anti-jellyfish serum antibodies are presented. These cases demonstrated the following facts: (1) Allergic reactions may play a significant pathophysiologic role in jellyfish envenomation of humans. (2) Elevated specific anti-jellyfish immunoglobulins may persist for several years. (3) Recurrence of the clinical cutaneous reaction to jellyfish stings may occur within a few weeks without additional contact with the tentacles. (4) It is apparent that serologic cross-reactivity between the sea nettle and the man-of-war occur, as do false-positive enzyme-linked immunosorbent assay (ELISA) serologic tests to either jellyfish venom.

Publisher Summary This chapter discusses the cross reactivity of lethal venoms to a monoclonal antibody (MAB). In an experiment described in the chapter, MAB to specific lethal factors from the venom of the Portuguese Man-O'war was prepared. The cross reactivity of K5 MAB with that of a number of other venoms available was examined. A strong cross reaction was seen with the venoms of the South American rattlesnake, Crotalus durissus terrificus, the oriental hornet, Vespa orientalis, the sea wasp, Chironex fleckeri, the sea nettle, Chrysaora quinquecirrha, and a purified component of the venom of the sea anemone Anemonia sulcata. K5 MAB did not react with APA and APC from the venom of the sea anemone, Anthopleura xanthogrammica or ατχI from Anemonia sulcata. No reaction was seen with the crude venom of Bolocera tuediae. To confirm this correlation, a quantity of Crotalus durissus terrificus venom was purified by immunochromatography with K5 MAB immobilized on Sepharose via cyanogen bromide.

The presence, nature, and composition of a layer of transparent mucinous material overlying the posterior epithelium (called here, 'the viscous layer of the posterior epithelium') was investigated in material from domestic cats. A number of different techniques were used. (a) A variety of different fixatives and histochemical stains was used to preserve and visualise the layer of examination by light microscopy. Frozen sections of fresh material were also examined after on-slide fixation. The preservation and appearance of the viscous layer was critically dependent on the type of fixative used and on minimal agitation during tissue processing. It appeared to contain sulphated acid GAGs, the staining of which was histochemically masked around pH 2.5. The use of frozen sections produced the most reliable preservation of the layer. (b) Ruthenium red or cetylpyridinium chloride was used to preserve the viscous layer for examination by transmission electron microscopy. It appeared in a dispersed form after stabilisation by ruthenium red and in a condensed form after stabilisation by cetylpyridinium chloride. (c) Freeze-dried tissue was examined by scanning electron microscopy. The viscous layer usually appeared as a band of coral- or moss-like material which was often many times the thickness of the posterior epithelium. Usually, the areas of the layer adjoining the posterior epithelium and the anterior chamber appeared more condensed when compared to the material between these two regions. The physiological significance of the viscous layer is discussed.

A nuclear envelope fraction is obtained from circulating erythrocytes of mature chickens. This fraction was characterized by chemical analysis, ultramicroscopic examination and electrophoretic analysis of the polypeptides. It is free of plasma membrane polypeptides, of hemoglobin and of deoxyribonucleohistone. Comparisons of the sodium dodecyl sulfate-polyacrylamide-gel electropherograms of the nuclear envelope fraction polypeptides with either chromosomal fraction or the total nonhistone fraction polypeptides from Triton X-100-washed nuclei indicate that certain major polypeptides are common to all fractions. This indicates that many chicken erythrocyte nonhistone “chromosomal” polypeptides may be primarily associated with nuclear structural elements which are not, in fact, deoxyribonucleohistone. Although this finding cannot be extended per se to other cells, it does suggest that caution should be exercised in describing nuclear components as “chromosomal” when this designation is intended to imply primary association with the deoxyribonucleohistone. This analysis of the polypeptides in the nuclear envelope fraction of the erythrocyte indicates that further study of the envelope fraction will provide new insights into nuclear structure and function.

Publisher Summary The sea nettle (Chrysaora quinquecirrha) kills its prey with potent venom, which is contained in nematocysts found on its tentacles. This venom is a complex mixture of enzymes and toxic agents. The venom is thermolabile and may be degraded by the proteolytic agents it contains. The purification of the venom's lethal factors has been hindered by low yields of pharmacological activity upon chromatography as well as the large volumes required to assess lethality in mice. This chapter describes a technique for the isolation of sea nettle lethal factor I via immobilized monoclonal antibodies. In the technique, monoclonal antibodies (MAB) were prepared using the crude venom for immunization.