Peripheral Displacement Research Articles

Extreme Signet Ring Cell Change in a Large B-Cell Lymphoma of Follicular Origin

We report a large B-cell lymphoma of follicular origin with extreme signet ring cell differentiation. Initially classified as follicular lymphoma on a fine needle core biopsy, the presence of cohesive sheets of extrafollicular signet ring cells triggered an excisional biopsy for further characterization. The excised lymph node revealed focal follicular hyperplasia, follicular lymphoma, and a neoplasm composed of vague nodules and sheets of large atypical cells, all of which virtually exhibited large clear intracytoplasmic vacuoles with peripheral displacement of nuclei. The tumor cells were negative for mucin and lacked immunoreactivity with pancytokeratin, but were strongly immunoreactive with CD20, BCL-2, BCL-6, and CD10 antibodies. Electron microscopy studies revealed electron-lucent vacuoles with no particular internal structure. This case is unique in that extreme signet ring cell differentiation somewhat obscured the true cytological identity of the interfollicular lymphoma and suggested alternative diagnoses.

Monitoring and Results Analysis of Tunnel Engineering

Through to the Henan tunnel engineering and observation hole, peripheral displacement measurement, measurement of subsidence of arch roof and surface subsidence measurement on-site real-time dynamic testing, obtained their changes over time curve, and the tunnel monitoring results were analyzed, thus improving the tunnel design and correctly guide the construction, ensure the safety and economy of the tunnel engineering.

Histologic Development of the Human Fovea From Midgestation to Maturity

To describe the histologic development of the human central retina from fetal week (Fwk) 22 to 13 years. Retrospective observational case series. Retinal layers and neuronal substructures were delineated on foveal sections of fixed tissue stained in azure II-methylene blue and on frozen sections immunolabeled for cone, rod, or glial proteins. Postmortem tissue was from 11 eyes at Fwk 20-27; 8 eyes at Fwk 28-37; 6 eyes at postnatal 1 day to 6 weeks; 3 eyes at 9 to 15 months; and 5 eyes at 28 months to 13 years. At Fwk 20-22 the fovea could be identified by the presence of a single layer of cones in the outer nuclear layer. Immunolabeling detected synaptic proteins, cone and rod opsins, and Müller glial processes separating the photoreceptors. The foveal pit appeared at Fwk 25, involving progressive peripheral displacement of ganglion cell, inner plexiform, and inner nuclear layers. The pit became wider and shallower after birth, and appeared mature by 15 months. Between Fwk 25 and Fwk 38, all photoreceptors developed more distinct inner and outer segments, but these were longer on peripheral than foveal cones. After birth the foveal outer nuclear layer became much thicker as cone packing occurred. Cone packing and neuronal migration during pit formation combined to form long central photoreceptor axons, which changed the outer plexiform layer from a thin sheet of synaptic pedicles into the thickest layer in the central retina by 15 months. Foveal inner and outer segment length matched peripheral cones by 15 months and was 4 times longer by 13 years. These data are necessary to understand the marked changes in human retina from late gestation to early adulthood. They provide qualitative and quantitative morphologic information required to interpret the changes in hyper- and hyporeflexive bands in pediatric spectral-domain optical coherence tomography images at the same ages.

Flow field investigations in rotating facilities by means of stationary PIV systems

The flow field inside rotating test sections can be investigated by means of particle image velocimetry (PIV) operated in the phase-locked mode. With this experimental approach, the measurement system is kept fixed and it is synchronized with the periodical passage of the test section. Therefore, the direct output of the PIV measurements is the absolute velocity field, while the relative one is indirectly obtained from proper data processing that relies on accurate knowledge of the peripheral velocity field. This work provides an uncertainty analysis about the evaluation of the peripheral displacement field in phase-locked PIV measurements. The analysis leads to the detection of the levels of accuracy required in the estimation of both the angular velocity and the position of the center of rotation to ensure correct evaluation of the peripheral displacement field. In this regard, a simple methodology is proposed to evaluate the center of rotation position with an accuracy below 1 px. Finally, a procedure to pre-process the PIV images by subtracting the peripheral displacement is described. The advantages of its implementation are highlighted by the comparison with the performance of a more standard methodology where the peripheral field is subtracted from the absolute velocity field and not directly from the PIV raw data.

Morphology of retinal vessels in the optic disk in a Göttingen minipig experimental glaucoma model

To compare the morphology of normal, healthy Gottingen minipig retinal vessels of the optic disk with experimentally induced glaucomatous optic disks in order to identify the glaucomatous excavation. Present results were compared to human glaucoma findings. Sixteen eyes from eight Göttingen minipigs were studied using fundoscopic photography and fluorescein angiography. Experimental glaucoma was then induced in the left eyes over 14 months, and changes in the optic disk vessels were assessed using fundoscopic photography and fluorescein angiography. The changes were compared with those previously reported in humans. Regarding the number of vessels, the location from where they emerge and the sectors of the optic disk that they cross, arterial and retinal vessels in Göttingen minipigs present a more asymmetric layout than in humans. The central excavation is filled by the central venous ring. Changes in the glaucomatous optic disk include arteriolar incurvation, and sometimes, nasal, and peripheral displacement of the arterioles that emerge between the ganglion cell axons of the neuroretinal ring. No angiographic changes were observed in the experimental glaucoma model. The changes in the glaucomatous optic disk of the minipig imply a predominant involvement of the arterioles. However, in humans with primary open-angle glaucoma (POAG), both the arterioles and the venules are displaced, and the central excavation is easier to distinguish, because of the absence of a central venous ring.

The Effects of Bone Resection Depth and Malalignment on Strain in the Proximal Tibia After Total Knee Arthroplasty

The clinical significance of tibial resection depth in total knee arthroplasty (TKA) is not clearly understood. The purpose of this study was to quantify the effect of tibial resection depth in TKA on tibial loading. Tibiae were coated with a photoelastic resin enabling full-field dynamic shear strain quantification in the tibial metaphysis during TKA loading. A standard resection level (5 mm) was compared to a resection level 15 mm distal to the joint line. Both had appropriate-sized tibial components. With 15 mm of tibial resection, strains increased up to 281% in the proximal and peripheral regions of the tibia during neutral loading and up to 315% anteriorly and 197% peripherally during varus loading. Distal resection levels result in significant smaller component size and relatively posterior and peripheral displacement of the implant. Changes in loading patterns in specimens with increased tibial resection depths have not previously been described.

Diagnosis and management of ovarian cyst accidents

Ovarian cyst accidents include cyst rupture, haemorrhage and torsion. Torsion commonly occurs to the whole adnexa and is not necessarily associated with an ovarian cyst. Suspected adnexal torsion should always be managed with early laparoscopy and de-torsion of the twisted tube or ovary. Ovarian cyst rupture and haemorrhage usually occur in association with physiological (functional) cysts and are generally self-limiting. Laparoscopy may be necessary in cases where the diagnosis is in doubt or for haemodynamic compromise. Clinical features of ovarian cyst accidents are nonspecific. Ultrasound is the first-line investigation and is diagnostic in the case of haemorrhage. Typical ultrasound findings have been described for ovarian torsion, including an enlarged oedematous ovary with peripheral displacement of follicles. Doppler blood flow findings are variable and not diagnostic. Recurrent cyst rupture or haemorrhage should be prevented by suppression of ovulation, usually with the combined oral contraceptive. Fixation of the ovary by a variety of techniques should be considered to prevent recurrent torsion.

Influence Of Ethnicity On The Human Term Placenta

Objective: To perform a morphometric comparative analysis of placentas from Indigenous mothers (Guajajara communities) and non-Indigenous mothers, inhabitants in the rural areas of Imperatriz County, Maranhao State, Brazil. Methods: Ten placentas from Indigenous mothers and 10 from non-Indigenous mothers, collected in a case-control study design, were submitted to stereological analysis. Results: Several differences between Indigenous placentas and non-Indigenous placentas were demonstrated. The placentas from Indigenous mothers were oval-shaped and pale (50%), heavier and larger, with higher placental weight index, surface of insertion, diameter, ratio between diameters, eccentricity and index of contour, and smaller shape coefficient. Volumes occupied by syncytiotrophoblast, trophoblast and villi, the villous surface and the trophoblast thickness were all bigger in the Indigenous placentas. Conclusion: The Indigenous placenta possesses a bigger functional reserve, being able, if necessary, to increase the number of vasculosyncytial membranes by the peripheral displacement of capillaries, facilitating the exchanges between maternal and fetal bloods.

A novel snap-through buckling behaviour of axisymmetric shallow shells with possible application in transducer design

In this study, the snap-through buckling behaviour of axisymmetric shells, subjected to axisymmetric horizontal peripheral load or displacement for various shell parameters and various boundary conditions, is investigated. Results obtained seem not to have been reported previously. An application of peripheral displacement type of loading is seen in metal-ceramic composite transducers developed by sandwiching a piezoelectric (PZT) ceramic between two metal end caps which serve as mechanical transformers for converting and amplifying the lateral displacement of the ceramic into an axial motion normal to the metal cap. In our numerical search, we have observed that snap-through and snap-back buckling is possible for shallow spherical caps for a very narrow range of the shell parameter used. When a hole is opened around the apex of the cap, buckling is possible for a larger range of the shell parameter. Obtaining the displacement amplification and the blocking or generative force for various material and geometric properties is necessary for the possible application of the findings in transducer design. The numerical results are presented in graphical forms.

Changes with age in the Golgi apparatus of rabbit spinal ganglion neurons

We studied the Golgi apparatus in spinal ganglion neurons of rabbits aged 12, 42 and 79 months.We found no structural changes, no indications of fragmentation, no indications of peripheral displacement affecting this organelle with advancing age.The volume of the perikaryon increased significantly with age, whereas the total volume of the Golgi apparatus remained essentially constant. Hence the mean percentage of perikaryal volume occupied by the Golgi apparatus decreased with age. This decrease was only in very minor part a consequence of lipofuscin accumulation, so that the ratio between the total volume of the Golgi apparatus and the functionally active volume of cytoplasm decreased with age. This decrease could be related to the reduced neuronal metabolism that occurs during ageing. It is possible that the delivery to the axon of newly synthesized proteins destined for fast transport is one of the Golgi apparatus roles that decrease with age.Finally, we found that the age-related quantitative changes in the Golgi apparatus did not differ between large light and small dark neurons.

Annexation of the interchromosomal space during viral infection.

The nucleus is known to be compartmentalized into units of function, but the processes leading to the spatial organization of chromosomes and nuclear compartments are not yet well defined. Here we report direct quantitative analysis of the global structural perturbations of interphase chromosome and interchromosome domain distribution caused by infection with herpes simplex virus-1 (HSV-1). Our results show that the peripheral displacement of host chromosomes that correlates with expansion of the viral replication compartment (VRC) is coupled to a twofold increase in nuclear volume. Live cell dynamic measurements suggest that viral compartment formation is driven by the functional activity of viral components and underscore the significance of spatial regulation of nuclear activities.

Reduced degenerative articular cartilage changes after meniscal allograft transplantation in sheep.

The objective of this study was to examine the gross changes after meniscal allograft transplantation with reference to the development of degenerative articular cartilage changes (DACC) and to examine the transplant behavior. The medial menisci of both knees in 32 Iceland sheep were operated on with either sham operation (C6), medial meniscectomy (M6), primary transplantation (P6), or secondary transplantation 3 months after meniscectomy (S6). These sheep were observed for 6 months. Another six sheep were observed for 3 months after meniscectomy (M3) and contralateral sham operation (C3). The DACC of the knee were visualized with an intra-articular toluidine blue injection. The dissemination area of DACC on the medial tibial plateau (MTP), the meniscal area, and the meniscus-free, exposed central area on the MTP were measured by computer image analysis based on digitized photos of the tibial plateau. These area measurements were calculated relative to the area of the MTP. The DACC in P6 knees had a mean of 4.3%, which was less than the 12.6% in M6 (P < 0.001) and the 16.1% in S6 (P < 0.001), but more pronounced than the 0.5% in C6 (P < 0.005). There were no detectable differences in DACC between M6, S6 and M3 (16.9%). The measurements of DACC were reproducible with correlation coefficient r = 0.97 on intra-tester test-retest measurements. The area of the free exposed MTP was larger in P6 and in S6 than in C6 (P < 0.001), demonstrating a displacement of the graft. S6 transplants showed shrinkage and were smaller than C6 menisci (P < 0.01). In conclusion, primary meniscal allograft transplantation reduced DACC within 6 months in sheep knees, but DACC were still present in transplanted knees. The meniscal transplants demonstrated peripheral displacement.

Natural Healing of Anterior and Posterior Attachments of the Rabbit Meniscus

The natural healing capacity of the anterior or posterior medial meniscal attachment after radial transection and the effect of such procedures on knee joint cartilage were investigated in 28 skeletally mature New Zealand white rabbits. Either the anterior (n = 14) or the posterior attachment (n = 14) was radially transected in the right knee joint. Fifty percent of the rabbits with each procedure were euthanized at 6 weeks and 50% at 12 weeks. The histologic characteristics of the healing tissue were evaluated, including immunohistochemical demonstration of nerve fibers. Histologic changes in the synovium and articular cartilage were graded for severity and extent. The concentration of proteoglycan fragments in joint fluid was analyzed before operation and at euthanasia. After both procedures, the transected attachment healed in a prolongated position resulting in peripheral displacement of the meniscus. The healing tissue at 6 weeks was composed mainly of granular tissue. By 12 weeks, the healing tissue at the anterior attachment had a ligament like structure, but at the posterior attachment, fibrocartilage like tissue had formed. Nerve fibers were found in the healing tissue, but connections to nerves in normal attachment or meniscal tissues were not found. Increased concentrations of proteoglycan fragments, articular cartilage degeneration, and synovitis were found in the operated knees. These data indicate that although the meniscal attachment can heal in a prolongated position, such a meniscus has lost its mechanical functions. Further, a joint protective function of the neoneurons is doubtful because of the lack of continuity with the adjacent meniscus. Rigid fixation of the attachment seems essential for a functional meniscal substitute.

Subcellular pathologic features of glucocorticoid-induced hepatopathy in dogs

SUMMARY Dogs are particularly susceptible to development of glucocorticoid-induced hepatopathy, but the mechanisms are not well understood. We investigated the pathogenesis of glucocorticoid hepatopathy by examining sequential morphologic and biochemical changes in the liver of dogs during steroid administration. Six adult Beagles were given prednisolone acetate (4 mg/kg of body weight, once daily for 24 days, im). Serum samples and percutaneous liver biopsy specimens were obtained before the start of the study (treatment day [td] 0) and at td 5, 10, 15, and 25. There were significant (P &lt; 0.05) and progressive increases in serum activities of alkaline phosphatase, γ-glutamyltransferase, and alanine transaminase. Light microscopic changes in liver biopsy specimens included progressive hepatocellular swelling and vacuolation. Electron microscopy revealed glycogen accumulation, peripheral displacement of organelles, and prominent dilatation of bile canaliculi, compared with findings at td 0. Liver biopsy specimens taken at td 25 had significantly (P &lt; 0.05) increased activities of the plasma membrane enzymes, alkaline phosphatase and γ-glutamyltransferase, and 5'-nucleotidase was significantly (P &lt; 0.01) decreased. Subcellular fractionation on reorientating sucrose density gradients revealed high-density peaks of alkaline phosphatase and γ-glutamyltransferase, compatible with a specific increase in the biliary canalicular component of the enzyme activities. Neutral α-glucosidase activity was shifted to the denser fractions, indicative of an increase in the proportion of rough to smooth endoplasmic reticulum and consistent with enhanced synthesis of plasma membrane proteins. There also was evidence for progressive increase in fragility of intracellular organelles, particularly lysosomes. These findings indicate that glucocorticoid hepatopathy in dogs is associated with progressive alterations not only to the plasma membrane, but also to other subcellular organelles.

Correlation of peripheral displacement thresholds and optic disc parameters in ocular hypertension.

Both peripheral displacement thresholds and measurement of optic disc parameters have been advocated in the early diagnosis of glaucoma at the stage before scotomata are detected on conventional visual field assessment. The peripheral movement displacement thresholds were measured in 50 eyes of 50 patients with ocular hypertension and a significant correlation was found with neuroretinal rim areas measured using a computerised image system. There was also a significant correlation with optic disc diameter but no correlation with cup-disc ratio. The results support the proposition that measurement of peripheral movement displacement thresholds may be a useful tool in the detection of early glaucomatous optic nerve damage.

Glucocorticoid hepatopathy: Effect on receptor-mediated endocytosis of asialoglycoproteins

Histologic and electron microscopic examination of liver tissue from glucocorticoid-treated dogs (GT dogs) showed a markedly abnormal hepatocellular morphology which consisted of severe hepatocellular swelling, vacuolation, and peripheral displacement of subcellular organelles. The abnormal cell morphology was typical of that seen in clinical cases of canine Cushing's Syndrome. The hepatocyte isolation procedure used here works equally well for the preparation of viable hepatocytes from both normal and GT dogs even though GT dogs displayed a pronounced hepatopathy. Cell yields (10(9) cells from a 30-cm3 section of liver) are similar to those reported for rat hepatocytes using whole liver in situ perfusion and cell viability is routinely greater than 85%. The isolation procedure preserved the "abnormal" state or swollen morphology of the hepatocytes from GT dogs and thus can be used in pathophysiological studies of glucocorticoid-induced hepatopathy. The isolated hepatocytes were 3.2 times greater in cell volume than normal hepatocytes. We also observed over a 12.3-fold increase in alkaline phosphatase activity and the appearance in both the liver and the serum of GT dogs of the unique, corticosteroid alkaline phosphatase isozyme (CALP). In spite of the obvious abnormal liver morphology and elevated serum and liver alkaline phosphatase activities, the function of the hepatic cell surface carbohydrate binding protein, the Gal/GalNAc or asialoglycoprotein receptor, was not impaired. We found a trend of about a 1.5-fold increase in the initial rate of ligand uptake as well as 1.6-fold more receptors on GT dog hepatocytes compared to normal hepatocytes. The ligand binding affinity of these receptors, as well as the rate of ligand degradation, was identical in hepatocytes isolated from normal and diseased dogs. When intestinal alkaline phosphatase (IALP) is used as the ligand, approximately 25% was exocytosed intact following endocytosis. These results demonstrate that dogs with glucocorticoid hepatopathy possess a normally functioning Gal/GalNAc receptor. Furthermore, these data are consistent with the hypothesis that structurally related IALP and CALP isozymes may also be metabolically related through the Gal/GalNAc receptor endocytosis pathway. That is, a portion of the IALP normally endocytosed through the Gal/GalNAc receptor pathway in glucocorticoid-treated dogs may be recycled and converted (hyperglycosylated) to the abnormal serum CALP isozyme rather than being degraded.

The Effect of Rapid Freezing on Uveal Melanomas

We studied the immediate effects of rapid freezing on 19 variously sized uveal melanomas that were subjected to cryoenucleation using liquid nitrogen and a cryoring by light and electron microscopy and tissue culture. The freezing time and the temperature of 11 lesions were recorded. The light microscopic finding of an intranuclear clear center with peripheral displacement of clumped chromatin against the nuclear membrane was suggestive of intranuclear ice crystal formation but did not indicate cellular death of the tumors. The major ultrastructural changes, including plasmalemmal breaks, dissolution of cytoplasmic matrix, and damage to various organelles, however, suggested acute necrosis in tumors not exceeding 7 mm in elevation. Failure of the melanoma cells to grow in tissue culture and positive staining with trypan blue support the contention of tumor death. The late effects of rapid freezing were also evaluated in another case of uveal melanoma. The eye was enucleated six months after cryopexy. Histopathologic findings showed that the tumor was necrotic. Failure of the neoplasm to regress (noted clinically) was related to edema and inflammatory infiltrates.

Ultrastructure of human cumulus-oocyte complexes from healthy and atretic follicles.

Follicular fluids with cumulus-oocyte complexes and granulosa cells were aspirated from antral follicles in healthy women at different stages of the normal menstrual cycle. The cumulus-oocyte complexes were processed for light and electron microscopy and classified as pre-ovulatory, healthy non-pre-ovulatory and atretic by certain light microscopical criteria, i.e. degree of expansion, number of layers and pycnotic nuclei in the cumulus investment, size of the peri-vitelline space and oocyte nuclear morphology. Their follicles were similarly classified by follicular steroid measurements and/or flow cytometric DNA analyses of the aspirated granulosa cells. A high degree of correlation between these classifications was found. Moreover, pre-ovulatory and atretic cumulus-oocyte complexes showed particular fine morphological characteristics, some of which were different while others appeared to be identical. Similarities were increased number of lipid droplets in the cumulus cells, widened peri-vitelline space, peripheral displacement or breakdown of the oocyte nucleus and disconnection of the junctions between cumulus cell projections and the oolemma. In addition to the criteria used for the light microscopical classification, pre-ovulatory complexes were characterized by release of the content of cortical granules while atretic ones displayed cumulus cells with pseudopodia-like projections, cumulus cells in the perivitelline space and lipid droplets in the ooplasm.

The evolution of intracellular responses to acrylamide in rat spinal ganglion neurons.

Acrylamide (30 mg or 50 mg/kg/day, 5 days each week) was injected intraperitoneally into rats for up to 4 weeks. Lumbar spinal ganglia, spinal cord and lumbrical muscle spindles were examined by light and electron microscopy at various times during this period. The first abnormalities in spinal ganglion neurons were seen at 7 days when an apparent increase in numbers of mitochondria, some being hypertrophic, were found in a few large light cells. This was 10 days before any significant Wallerian degeneration was found in muscle spindle sensory fibres. Mitochondrial changes became more marked with time and were later associated with RER disruption, loss of neurofilaments and peripheral displacement of the nucleus thus mimicking chromatolysis of the axon reaction. All these changes began, however, before axon degeneration. Evidence of increased satellite cell activity was maximal at 21 days. These changes are discussed in the light of the possibility that calcium entry into the cell may be seriously increased early in the intoxication as a direct result of the presence of acrylamide and that many of these cellular features are secondary responses to such an event. Distal degeneration of axons seems likely to be secondary to the perikaryal changes.

Zooplanktonic Communities of the Divergence Zone in the Northwestern Alboran Sea

Abstract. Using principal component analysis, the zooplanktonic communities of the divergence zone in the northwestern sector of the Alboran Sea were studied. The study was based on 35 vertical trawls in the 200 metres superficial level. The two first components account for 65 % of the total variance. The first component is a contrast between a warm water coastal community (characterized by low specific diversity and the abundance of Cladocera and Copepoda such as Acartia clausi, Centropages chierchiae and Temora stylifera) and a community of cold subsuperficial water distinguished by high specific diversity and a low number of individuals, one of its most characteristic elements being the eggs and larval stages of the Conostomasidae Maurolicus muelleri. The second component appears to be associated with an ecotone between the communities previously cited, and with a specific grouping (Rhincalanus nasutus, Eucalanus monachiis, Pseudocalanus elongatus, Temora longicornis, etc.) resulting from the peripheral displacement of subsuperficial elements brought to the surface by the cyclonic circulation of water masses between the Atlantic current and the Spanish coast.