Types Of Morphological Changes Research Articles

Radiation induced modifications in ultra-high molecular weight polyethylene

The effect of proton irradiation dose on the morphology of ultra high molecular weight polyethylene (UHMWPE) was studied. The radiation dose was varied from 0.09402 to 0.87 Mrads. The thermal behavior of the irradiated samples was investigated by submission to two heating cycles. The proton irradiation produces morphological changes in the mole fraction of crystallizable units, sequence length distribution, and crystallite thickness and distribution. The type of morphological changes is dependent on irradiation dose and thermal cycle. The low proton radiation dose produces only slight changes in the morphology of UHMWPE. More pronounced morphological changes are observed for the higher proton radiation dose.

Characterization of oil palm MADS box genes in relation to the mantled flower abnormality

In vitro propagation of oil palm (Elaeis guineensis Jacq.) frequently induces a somaclonal variant called ‘mantled’ abnormality, in which the stamens of both male and female flowers are transformed into carpels. This leads to a reduced yield or complete loss of the harvest of palm oil. The high frequency of the abnormality in independent lines and the high reversal rate suggest that it is due to an epigenetic change. The type of morphological changes suggest that it involves homeotic MADS box genes that regulate the identity of the flower whorls. We have isolated a number of MADS box genes from oil palm inflorescences by a MADS box-directed mRNA display approach. The isolated partial cDNAs included genes that were likely to function at the initial stages of flowering as well as genes that may function in determination of the inflorescence and the identity of the flower whorls. For four genes that were homologous to genes known to affect the reproductive parts of the flower, full length cDNAs were isolated. These were a B-type MADS box gene which may function in the determination of stamen formation, a C-type gene expected to be involved in stamen and carpel formation, and two putative SEP genes which act in concert with the A-, B- and C-type MADS box gene in determining flower whorl formation. The B-type gene EgMADS16 was functionally characterized as a PISTILLATA orthologue; it was able to complement an Arabidopsis thalianapi mutant. Whether EgMADS16, or any of the other EgMADS genes, are functionally involved in the mantled condition remains to be established.

On the origins of morphological disparity and its diverse developmental bases

It has been repeatedly claimed that morphological novelties are an unresolved problem in evolutionary theory. Several definitions of novelty exist but most emphasize that novelties imply qualitative changes on the phenotype and not the quantitative gradual changes favored in the neo-Darwinian approach to evolutionary theory. This article discusses how the concept of novelty is used to describe aspects of morphological evolution that are not satisfactorily explained under the modern synthesis. In this article, it is suggested that there is a repertoire of morphological changes rather than two discrete qualitatively different types of morphological change. How these different types of morphological changes can be understood from the diversity of developmental mechanisms existing in animal development is explored. Specifically, it is proposed that animal morphology and its variation can be understood from the spatial patterns produced by a set of basic developmental mechanisms and their combination. Some specific examples of these kinds of morphologic changes are explained.

Presynaptic and Postsynaptic Roles of NO, cGK, and RhoA in Long-Lasting Potentiation and Aggregation of Synaptic Proteins

Recent results suggest that long-lasting potentiation at hippocampal synapses involves the rapid formation of clusters or puncta of presynaptic as well as postsynaptic proteins, both of which are blocked by antagonists of NMDA receptors and an inhibitor of actin polymerization. We have investigated whether the increase in puncta involves retrograde signaling through the NO-cGMP-cGK pathway and also examined the possible roles of two classes of molecules that regulate the actin cytoskeleton: Ena/VASP proteins and Rho GTPases. Our results suggest that NO, cGMP, cGK, actin, and Rho GTPases including RhoA play important roles in the potentiation and act directly in both the presynaptic and postsynaptic neurons, where they contribute to the increase in puncta of synaptic proteins. cGK phosphorylates synaptic VASP during the potentiation, whereas Rho GTPases act both in parallel and upstream of cGMP, in part by maintaining the synaptic localization of soluble guanylyl cyclase.

The role of enteroclysis and roentgen anatomy of jejunum and ileumin Crohn's disease

The aims of this research were: 1) to establish the value of enteroclysis in detection of morphological changes of jejunum and ileum in cases with suspected Crohn's disease and 2) to establish types of morphological changes of jejunum and ileum in patients with Crohn's disease. The study compared two groups of people who voluntarely accepted to be examined: a control group and a study group. The control group included 11 healthy people, without gastrointestinal symptom. The study group included 16 patients with Crohn's disease. Single and double-contrast enteroclysis were performed in both groups. Afterwards, we defined parameters which were compared in these groups. We concluded that according to statistics there are significantly lower values of the width of the jejunal and ileal lumen and the number of mucosal folds (per 1 cm) of the jejunal and ileal wall in the examined group in contrast to the control group. Also, according to statistics there are significantly higher values of the width of the jejunal and ileal wall and the thickness of mucosal folds of the jejunum and ileum in the study group in contrast to the control group.

Exploring ischemia-induced vascular lesions and potential pharmacological intervention strategies.

Structural changes in vessels under the influence of ischemia play an important role in the pathogenesis of many diseases, most important of which are stroke and myocardial infarction or myocardial insult. Over the years, information has been gathered, which implicate a role for ischemic vascular changes in the pathogenesis of crush-syndrome, atherosclerosis and other vascular diseases. When blood vessels are damaged they become unresponsive to a stimulus, which normally elicits vasodilatation and can lead to intraluminal thrombosis and ischemic events. The aim of this review is to explore the structural changes seen in vessels affected by ischemia reperfusion injury. With ischemia, the development of observable changes to vascular structure is multifactorial. One key factor is reperfusion ischemic injury. Moreover, the duration of the ischemic event is an important factor when determining both the prognosis and the type of morphological change that is observable in affected vessel walls. In this regard, the deleterious progression of blood flow impairment and its severity depends on the specific organ involved and the type of tissue affected. Further, there are regional differences within affected tissues and the degree of microvascular injury is well correlated with differences in the nature and severity of the ischemic event. Any method aimed at preventing and treating ischemic reperfusion injuries in vessels, based on these investigations, should likewise be able to decrease the early signs of brain, cerebrovascular and heart injury and preserve normal cellular architecture.

SPECT/CT in tumor imaging: Technical aspects and clinical applications

Diagnostic imaging has gained a major role in the management of patients with cancer and has made a further step forward with the introduction of fusion techniques into the field. This technology provides hybrid images of two independent modalities, a functional scintigraphic technique and an anatomical procedure, yielding a superior imaging study. Scintigraphy is based on the use of single photon or positron emitting tracers providing a description of function or processes, whereas computed tomography (CT), ultrasound, or magnetic resonance imaging (MRI) depict the precise localization and type of morphological changes that have occurred in the lesions. Initial attempts to coregister the functional and anatomical information following acquisition of the two imaging modalities on separate machines, in different sessions, failed to disclose the proper alignment with precise coregistration, in particular for non-head studies, and were associated with patient preparation and mathematical modeling that were too cumbersome to be used on a routine basis. The recent introduction of a hybrid imaging device containing a low dose CT system and a gamma camera on a single gantry enabled the sequential acquisition of the two imaging modalities, with subsequent merging of data into a composite image display. These hybrid studies have led to a revolution in the field of imaging, with highly accurate localization of tumor sites, assessment of invasion into surrounding tissues, and characterization of their functional status. © 2003 Elsevier Inc. All rights reserved.

Exploring the Role of Morphology in the Evolution of Spanish (review)

202ReviewsLa corónica 31.1, 2002 Rini,Joel. Exploring the Role of Morphology in the Evolution of Spanish . Amsterdam/Philadelphia:John Benjamins, 1999. Pp. xvi + 187. ISBN 1-55619-956-2 (US), ISBN 90-272-3685-2 (Europe). In his second book on Spanish historical linguistics, Rini takes on the ambitious task of proposing new solutions to old problems, something which has generally characterized his work. Here, his efforts are directed at finding new solutions to nine "unsolved mysteries of Spanish historical grammar " (xii), which are presented in Chapters 2-5 of this book. Chapter 2 deals with morphological change in (1) the retention of initial /o/ in dormir, morir, podrir vs. subir, cumplir, cubrir, (2) the tonic vowel in verbs such as Old Spanish ove to Modern Spanish hube, and (3) the intertonic vowel in verbs such as Old Spanish aperçebir to Modern Spanish apercibir. Chapter 3 presents three changes traditionally thought to be phonological, (4) /ee/ > /e/ in Old Spanish veer, (5) /ée/ > /éi/, as in Latin bovem > Old Spanish huee > Modern Spanish buey, and (6) the presence or absence of the final IAI in the vosotros and voseo imperatives, while Chapter 4 deals with a single topic also thought to be phonological, (7) the loss of the intervocalic /d/ in the vosotros endings. Finally, Chapter 5 deals with changes traditionally thought to be syntactic, (8) the -y of Spanish hay and (9) the origin of Spanish eres. Rini carefully states that only two of the essays on these nine topics (corresponding to numbers 5 and 8) have been published previously as Rini 1998a and Rini 1998b. Even though topic 7, specifically examples (1), (9) and (12) on pages 123, 127 and 129, is based on some material from Rini 1996, the precise topic of the loss of /d/ is dealt with here for the first time. In the same way, topic 4, which at first glance would appear to be similar to Rini 1991, in fact treats an entirely different aspect of /ee/. The book's greatest strengths are Rini's carefully argued and imaginative solutions to these problems based on morphological connections. He leaves almost no stone unturned in his critical evaluation of the possible explanations for these "problematic developments" (xi), including those of his own invention. Chapter 1 begins with a summary of previous works on Spanish morphology (1-9), which will appeal to one of Rini's targeted audiences, "students and specialists of Spanish historical grammar" (xiii). His other targeted audience, "students and specialists of general historical linguistics", must wait until the second part of the chapter to find mention of some of the excellent treatments of morphology in general historical linguistics, especially Hans Hock 1991. In this second section (9-28), Rini departs from La corónica 31.1 (Fall, 2002): 202-206 Reviews203 previous definitions by using "morphological change" rather than "analogy " to refer to "any change in the phonetic structure of any part of a word ... that cannot be accounted for in purely diachronic phonetic terms ... [by which] words that are semantical!}', syntactically, or already structurally ... similar become more similar to each other in form" (10). He then restricts the term "analogy" to one type of morphological change, i.e., "proportional analogy" or "four-part analogy", as in dog/dogs : cow/X = cows (12). I wonder, however, why four-part analogy should receive a special term at all, since it is simply a formulation of a model by which another form changes, and such a model is the basis for all morphological change. The example above, rather than being represented as a proportion, could simply be written as "add -s to the stem". All the other subtypes of morphological change Rini identifies could be represented in this way as well. Rini himself points out that backformation is a type of four-part analogy in which a new base form is created as in "operation/operate : orientation/X = orientate (replacing 'orient')" (25). Even though Rini rejects the possibility that leveling within a verb paradigm can be represented through four-part analogy (14), he clearly accepts that extra-paradigmatic leveling can be shown in this way (136). I propose that extra-paradigmatic...

Activity-induced changes of spine morphology.

Spine morphology has been shown in recent years to exhibit a high degree of plasticity. In developing tissue such as organotypic slice cultures, shape changes in spines as well as reorganization of the postsynaptic density (PSD) occur within minutes. Furthermore, several studies have shown that these and other changes can be induced by or are dependent on synaptic activation. Formation of filopodia, enlargement of spines, formation of spines with perforated PSDs, appearance of new spines, and formation of specific types of synapses such as multiple synapse boutons (MSBs), in which two spines contact the same terminal, have all been reported to be induced in an activity-dependent manner. The common denominator of most of these different processes is that they are calcium and NMDA receptor dependent. Their time course, however, may vary. Some appear quite rapidly after stimulation (e.g., filopodia, perforated synapses), while others are clearly more delayed (e.g., formation of spines, appearance of MSBs). How these different structural changes relate to each other, as well as their functional significance, have therefore become intriguing issues. The characteristics of these different types of morphological changes are reviewed, with a discussion of the possibility that structural plasticity contributes to changes in synaptic efficacy.

Pancreatic imaging by ultrasonography in type 1 diabetes mellitus

Various types of morphological changes in pancreas have been demonstrated in patients with type 1diabetes mellitus. We evaluated 35 patients suffering from type 1 diabetes mellitus and compared themwith 15 age, sex and BMI matched healthy controls to access the morphology of the pancreas byultrasonography which is non-invasive, economic, simple and easily available. It was found thatpatients with type 1 diabetes mellitus have a reduction in total area of the pancreas, increased diameterof the main pancreatic duct and presence of fibrosis and calcification which was more pronounced inpatients having longer duration of diabetes.

An example of intralacustrine evolution at an early stage: the freshwater ostracods of the Miocene crater lake of Steinheim (Germany)

I present the findings of two detailed studies on Steinheim lake ostracods carried out over the last eight years. The 178 samples studied cover a combined section about 30 m thick, comprising the whole sequence of seven planorbid beds. Of the 53 species found, 44 occur in the basic sediment layers, the kleinibeds. In contrast, all of the subsequent beds contain 16 species, and only seven species withstood the extinction at the kleini–steinheimensis boundary.This may be mainly due to the loss of littoral habitats brought about by a constantly increasing lake level, as the majority of the species in the kleinibeds were shallow water dwellers. Long-term lake level fluctuations are considered the most important external factor of the post-kleini period. Density fluctuations of the ostracods Pseudocandona steinheimensis and Potamocypris gracilis broadly reflect these water level fluctuations. At the beginning of the sulcatusperiod, when the lake level was very high, some species show morphological changes in their carapaces. During this time Leucocythere immigrata split into the daughter species L. sieberi and L. esphigmena. In the following trochiformis period, when the water level was lowest, the most curious carapace sculptures appear. The morphological changes detected, however, cannot simply be interpreted as ecophenotypic. The speciation event in Leucocythere, the non-recolonization with ubiquitous species during the low water level stage (trochiformis period), as well as the types of morphological changes indicate mainly evolutionary processes, as also the planorbid molluscs prove. Moreover, ostracods and planorbids show convergent evolutionary patterns. Compared with data on ostracod speciation in ancient lakes, the ostracod assemblage of Lake Steinheim seems to be a good palaeontological example of intralacustrine evolution at an early stage.

A new concept for risk assessment of the hazards of non-genotoxic chemicals — electronmicroscopic studies of the cell surface. Evidence for the action of lipophilic chemicals on the Ca 2+ signaling system

Recently, we presented evidence for the localization of components of the cellular Ca 2+ signaling pathway in microvilli. On stimulation of this pathway, microvilli undergo characteristic morphological changes which can be detected by scanning electron microcopy (SEM) of the cell surface. Here we show that both receptor-mediated (vasopressin) and unspecific stimulation of the Ca 2+ signaling system by the lipophilic tumor promoters thapsigargin (TG) and phorbolmyristateacetate (PMA) are accompanied by the same type of morphological changes of the cell surface. Since stimulated cell proliferation accelerates tumor development and sustained elevation of the intracellular Ca 2+ concentration is a precondition for stimulated cell proliferation, activated Ca 2+ signaling is one possible mechanism of non-genomic tumor promotion. Using isolated rat hepatocytes we show that all tested lipophilic chemicals with known tumor promoter action, caused characteristic microvillar shape changes. On the other hand, lipophilic solvents that were used as differentiating agents in cell cultures such as dimethylsulfoxide (DMSO) and dimethylformamide also, failed to change the microvillar shapes. Instead DMSO stabilized the original appearance of microvilli. The used technique provides a convenient method for the evaluation of non-genomic carcinogenicity of chemicals prior to their industrial application.

The role of the Lps gene in experimental ulcerative colitis in mice.

The effects of the Lps gene on the development of experimental ulcerative colitis were studied in two genetically different mouse strains: C57B1 and C3H. Acute colitis was induced by adding 3% dextran sulfate sodium (DSS) to the drinking water for a 7-day (C57B1 and C3H) or a 10-day (C57B1) experimental period. Although the DSS treatment initiated the same type of morphological changes in the colon in all groups of mice, an earlier onset and persistent intestinal bleeding occurred in the Lpsn mice (sensitive to lipopolysaccharide, LPS) in comparison with the Lpsd mice (hyporesponsive to LPS). Rectal bleeding appeared on day 7 in 90% of the Lpsn compared to 13% of the Lpsd mice (p < 0.0001). In C57B1 mice, followed for three additional days, 50% of the Lpsn mice died and the surviving animals showed as well as rectal bleeding a large number of Gram-negative bacteria in the liver and spleen. In contrast, the Lpsd mice of the C57B1 strain appeared unaffected by the treatment, although a transient rectal bleeding occurred in 90% on day 8. Also, significantly fewer Gram-negative bacteria were found in the liver and spleen. Even though significantly increased serum endotoxin levels were seen in all DSS-treated groups compared to controls on day 7, the serum levels of TNF alpha were significantly increased only in the Lpsn mice. In DSS-induced colitis the Lpsn genotype conferred on the mice an increased LPS susceptibility, resulting in an augmentation of the inflammatory response to Gram-negative bacteria and their endotoxins. The results suggest that LPS-induced host effector mechanisms significantly enhanced the intestinal bleeding, systemic inflammatory response, and mortality in mice with DSS-induced colitis. In addition, the host defense against the invading and systemically spread bacteria most probably involved additional genes.

Morphodynamics of meso- and macrotidal beaches: examples from central Queensland, Australia

Detailed measurements of the morphology, waves, and longshore and cross-shore currents were conducted on two beaches on the low- to medium-energy, macrotidal coastline of central Queensland (Australia). Nine Mile Beach is characterised by a relatively steep upper profile, a low-gradient intertidal zone with one or two swash bars, transverse bar/rip morphology at low-tide level and a very low-gradient, dissipative subtidal zone. The beach is composed of fine to medium sand and experiences a modal wave height of 0.75 m and a mean spring-tide range of 3.6 m. Lambert's Beach possesses a steep, coarse-grained, reflective upper profile, and a low-gradient dissipative low tide terrace composed of fine to medium sand. Subdued rip channels intersect the low tide terrace and the beach is subject to a modal wave height of 0.6 m and a mean spring-tide range of 4.6 m. The two beaches are classified as Low Tide Bar/Rip and Low Tide Terrace beaches, respectively, following the model of Masselink and Short (1993). During the present investigation, the Low Tide Bar/Rip beach (Nine Mile Beach) exhibited a larger temporal variability than the Low Tide Terrace beach (Lambert's Beach), despite similar hydrodynamic conditions over the survey period. This difference is principally attributed to the differences in the beach morphologies and the types of morphological changes that occurred. On Nine Mile Beach, morphologic changes were primarily associated with secondary features (swash bars and low tide bar/rip system), whereas on Lambert's Beach the changes in morphology were largely the result of adjustments of the overall beach profile. A number of surf zone processes were investigated, including incident-wave attenuation, infragravity-wave energy, bed return flow and longshore currents. The influence of the tide on surf zone dynamics was found to be insignificant, except in the case of longshore currents. On Nine Mile Beach, the longshore current associated with the nearshore cell circulation was stronger during low tide. On Lambert's Beach, the shore-parallel current on the low tide terrace was largely driven by the tide. A beach profile zonation was defined for Nine Mile Beach and Lambert's Beach based on an examination of the varying influence of swash, surf zone and shoaling wave processes. The four-part tidal zonation consists of: (1) an upper intertidal zone across which swash and aeolian processes are the major influence; (2) a mid-intertidal zone dominated by swash and surf zone processes; (3) a lower intertidal zone controlled by surf zone and shoaling wave processes; and (4) a subtidal zone largely influenced by shoaling wave processes.

Influence of HIV status on pathological changes in tuberculous pleuritis

Setting: The AIDS epidemic has been associated with an increase in the incidence of tuberculosis, pulmonary or extrapulmonary. Objective: To compare morphological changes in tuberculous pleurisy, and response to therapy in HIV-positive and-negative patients. Design: 57 consecutive patients admitted between January and August 1991 with tuberculous pleurisy who were biopsy proven were studied. 36 were HIV-positive and 21 were HIV-negative. Results: 3 types of morphological changes were observed: reactive, hyporeactive and non-reactive. Hypo- and non-reactive patterns were found in 14 of 36 HIV-positive patients but in only 2 of 21 HIV-negative patients ( P < 0.02). In the HIV-positive group, 10 of the 14 with hypo- or non-reactive patterns had other HIV-related complications, compared to 6 of 22 with reactive patterns ( P < 0.01). When HIV-positive patients' response to therapy was investigated, 2 of 5 patients with hypo- and non-reactive patterns improved compared to all 13 with reactive patterns ( P < 0.05). Conclusion: A hypo- or non-reactive tissue reaction in HIV-positive patients with tuberculous pleuritis seems to indicate a less favourable prognosis.

Structure and bioelectricity of single neurons of Helix pomatia in the intact nervous tissue during epileptic activity: Simultaneous evaluations by confocal microscopy and intracellular recordings of membrane potential changes

1. 1. Neuronal shape during epileptic activity was studied with confocal laser scanning microscopy and intracellular recording of identified neuronal individuals in the buccal ganglia of Helixpomatia. Simultaneous observations of single Lucifer Yellow stained fibers and epileptic activity of the same neuron were done. 2. 2. During epileptic activity, the development of several types of morphological changes were observed: local and extended swellings, constrictions, stretching of neuronal processes and release of intracellular material. 3. 3. Morphological alterations did not only occur with epileptic activity but could also appear due to extended laser exposure of fluorescent neuronal processes. 4. 4. Phototoxicity is discussed as a limiting factor for a valid interpretation of the morphological changes observed by confocal microscopy.

Cyclophosphamide-induced diabetes in Long-Evans Tokushima Lean rats: Influence of ovariectomy on the development of diabetes

We studied the effect of treatment with cyclophosphamide (CY) on the incidence of diabetes in Long-Evans Tokushima Lean (LETL) rats, a newly established strain of spontaneously type I diabetic rats. The overall incidence of diabetes among 356 LETL rats treated with CY was 25.6%, which was significantly higher than the 10.5% among 857 untreated LETL rats at 27 weeks of age, and there was no significant sex difference. The incidence of CY-induced diabetes in adult (>16 weeks of age) female LETL rats was 7.7% ( 10 130 ), which was significantly lower than that in other CY-treated groups of LETL rats. No diabetes mellitus was induced by administration of CY to 23 diabetes-resistant LETO rats. There were no significant differences in the degrees of hyperglycemia or hyperketonemia in spontaneously and CY-induced diabetic LETL rats, but the plasma glycated albumin level of CY-induced diabetic rats (10.3% ± 2.1%) was significantly higher than that of spontaneously diabetic rats (8.2% ± 1.3%), suggesting that plasma glucose levels increased more rapidly in the latter. More than half of the diabetic rats showed type C or D morphological changes of the islets, ie, atrophic change with little mononuclear cell infiltration or almost complete loss of the islets. However, distributions of various types of morphological changes in the islets were not significantly different in the two groups. Ovariectomy (OVX) significantly increased the incidence of CY-induced diabetes in adult female rats from 7.7% to 20.8%. The number of CD8 + cells was significantly increased in noncastrated adult female LETL rats and decreased to the level of other groups after OVX. These results indicate that CY is diabetogenic in our colony, and that its effect is related to the gonadal hormone environment.

Evaluation of a fungal antagonist, Phaeotheca dimorphospora, for biological control of tree diseases

Phaeotheca dimorphospora, which was first isolated from elm wood and found to be antagonistic in vitro against the Dutch elm disease pathogen Ophiostoma ulmi, was tested for antifungal activity in vitro against other tree pathogens by a variation of the agar layer technique. Phaeotheca dimorphospora produced antifungal compounds that were strongly inhibitory against a wide range of tree pathogens in addition to O. ulmi, such as Gremmeniella spp., Armillaria spp., Septoria musiva, Verticillium albo-atrum, Cylindrocladium floridanum, Phytophthora sp., Nectria galligena, and Heterobasidion annosum. Under light and interference microscopy, four types of morphological changes were observed in the pathogens tested: swelling of hyphae, production of resting spores such as chlamydospores and of sclerotia, extrusion of cytoplasm from hyphal tips, and bursting and destruction of mycelium. Chloroform-soluble antagonistic compounds were extracted that showed both fungicidal and fungistatic effects on the test organisms. Key words: Phaeotheca dimorphospora, biological control, fungal antagonist, hyphal interactions, antifungal metabolites, tree diseases.

Activated eosinophils in adult coeliac disease: evidence for a local release of major basic protein.

The eosinophil population is increased in the jejunal mucosa of patients with coeliac disease. Eosinophils may participate in the mucosal damage by releasing their granule components that have cytotoxic properties such as eosinophil cationic protein (ECP) and major basic protein (MBP). This study aimed to assess the presence of ECP and MBP in the jejunal mucosa of 10 adult patients with active coeliac disease who presented with villous flattening. Endoscopic jejunal biopsy specimens were obtained from macroscopically flattened jejunal mucosa and were processed for ultrastructural study and immunogold labelling using anti-MBP, anti-ECP, and anti-IgA antibodies. Numerous eosinophils were found in the upper part of the lamina propria and showed two types of morphological change: some were lytic and others exhibited ultrastructural signs of activation, containing altered granules with fading of the central core. IgA plasma cells were intermingled with eosinophils and had dense deposits on the external side of their cytoplasmic membrane. MBP was detected in central cores of granules but also diffusely in their matrix and in tight association with dense extracellular deposits. Conversely, ECP was detected only in the matrix of eosinophil granules. This study showed that numerous eosinophils are in an activated state in the mucosa of patients with active coeliac disease and release cytotoxic proteins such as MBP, which could contribute to the mucosal damage. The observation that eosinophils and IgA plasmocytes were closely associated in the mucosa supports a role for IgA in eosinophil recruitment and activation in coeliac disease.

Morphological Changes in the Geniculocortical Pathway Associated with Monocular Deprivationa

To summarize (Fig. 10), the structural consequences of monocular deprivation include the following changes: the relay cells in the binocular segments of the deprived geniculate layers shrink and contain less of the possible neurotransmitter NAAG. These changes appear to be secondary to a loss of terminal synaptic arbor. Certainly, deprived geniculocortical cells project to smaller ocular dominance patches in layer IV of visual cortex, where they make fewer and abnormal synapses. As a result, they activate ocular activation columns that, in addition to being small, are faint and usually fail to extend into extragranular layers. This failure to extend to other layers probably results from a failure of the poorly activated deprived-eye cells in layer IV to compete successfully with neighboring experienced-eye cells in layer IV, resulting in a loss of connections from layer IV to other layers (Fig. 11). Thus, the primary effect of monocular deprivation is probably the disruption of the geniculocortical synapse, with the other changes, such as cell size, and possibly the change in neurotransmitter content, being secondary. The disrupted synapse would result in poorly driven cortical cells and faint ocular activation columns, which in turn would bias a secondary competition for access to cells in extragranular layers. There are certain general principles that unite the findings presented in this chapter with the others in this session. First, there are similarities in the types of morphological changes observed, for example, changes in the number and size of synaptic terminals, as well as mitochondrial changes. This implies that there are similar changes during development and adult plasticity and also similar changes in vertebrates and invertebrates. Second, it is not so much the amount of activity that determines these changes, but the pattern of activity. In my results, the relative imbalance in activity is important, but not the absolute amount (for example, the columns activated by the 8-hr eye of an AME 8/1 are different from those activated by the 8-hr eye of an AME 8/8). Similarly, the binocular segment, where there was an imbalance and competition could occur, was affected, whereas the monocular segment, where there was no imbalance and competition could not occur, was not. Finally, the recent results of Reiter and Stryker suggest that monocular deprivation produces changes only when the activity of the presynaptic cell and the postsynaptic cell are correlated.(ABSTRACT TRUNCATED AT 400 WORDS)