First Signs Of Degeneration Research Articles

Central acetabular osteophytes (CAO) are more prevalent in the borderline developmental dysplastic hip (BDDH) patients: a propensity-score matched CT study

BackgroundThe acetabular fossa often showing the first signs of degeneration, Central acetabular osteophytes (CAO) have been increasingly recognized during hip arthroscopy. The purpose of this study was to investigate the condition of CAO in BDDH hips and compare cotyloid fossa size between the BDDH and the non-BDDH hips on CT images.MethodsWe performed a retrospective analysis of prospectively collected data of hip CT images of FAI or labral injury patients. A 1:2 propensity-score matched observational study comparing the linear length of cotyloid fossa was analyzed. Cotyloid fossa width (CFW) and cotyloid notch width (CNW) were measured on axial images, cotyloid fossa height (CFH) and cotyloid fossa depth (CFD) were measured on coronal images. Within the CAO patients, we performed central acetabular decompression (CAD) and then observed the morphology change in fossa.ResultsPropensity-score matching yielded 61 BDDH hips and 122 non-BDDH hips. BDDH hips had a higher prevalence of CAO and a decreased linear length of cotyloid fossa (CFW, CFH and CNW). In the BDDH group, 33 hips underwent CAD, postoperative CFW, CFH and CNW were significantly increased (p < .001 for all), and had no statistical difference compared with the non-BDDH hips (p = .193, p = .132, p = .421, respectively).ConclusionBDDH hips had a significantly higher prevalence of CAO than adequate acetabular coverage hips. After the procedure of CAD, BDDH hips were found to have acetabular parameters (CFW, CFH, CNW) and were restored to that of the control hips.

Hip preservation surgery and the acetabular fossa.

As our understanding of hip function and disease improves, it is evident that the acetabular fossa has received little attention, despite it comprising over half of the acetabulum’s surface area and showing the first signs of degeneration. The fossa’s function is expected to be more than augmenting static stability with the ligamentum teres and being a templating landmark in arthroplasty. Indeed, the fossa, which is almost mature at 16 weeks of intrauterine development, plays a key role in hip development, enabling its nutrition through vascularization and synovial fluid, as well as the influx of chondrogenic stem/progenitor cells that build articular cartilage. The pulvinar, a fibrofatty tissue in the fossa, has the same developmental origin as the synovium and articular cartilage and is a biologically active area. Its unique anatomy allows for homogeneous distribution of the axial loads into the joint. It is composed of intra-articular adipose tissue (IAAT), which has adipocytes, fibroblasts, leucocytes, and abundant mast cells, which participate in the inflammatory cascade after an insult to the joint. Hence, the fossa and pulvinar should be considered in decision-making and surgical outcomes in hip preservation surgery, not only for their size, shape, and extent, but also for their biological capacity as a source of cytokines, immune cells, and chondrogenic stem cells.Cite this article: Bone Joint Res 2020;9(12):857–869.

Lewy pathology is not the first sign of degeneration in vulnerable neurons in Parkinson disease

To determine whether evidence of neuronal dysfunction or demise preceded deposition of Lewy pathology in vulnerable neurons in Parkinson disease (PD). We examined the extent of nigral dysfunction and degeneration among 63 normal, incidental Lewy body disease (ILBD), and PD cases based on tyrosine hydroxylase (TH) immunoreactivity and neuron densities, respectively. The relationship between these markers and Lewy pathology (LP) burden in the substantia nigra (SN) and Braak PD stage was assessed. Compared with normal subjects, ILBD cases displayed a significantly higher percentage of TH-negative cells and lower neuronal densities in the SN as early as Braak PD stages 1 and 2, before LP deposition in the nigrostriatal system. ILBD nigral neuron densities were intermediate between normal subjects and PD cases, and TH-negative percentages were higher in ILBD than either normal or PD cases. Furthermore, neuron density and neuronal dysfunction levels remained relatively constant across Braak PD stages in ILBD. These results suggest that significant neurodegeneration and cellular dysfunction precede LP in the SN, challenging the pathogenic role of LP in PD and the assumption that ILBD always represents preclinical PD.

Testes degeneration in ants: a histological study of Gnamptogenys bicolor

Allard, D., Ito, F., Aikawa, Y., Gotoh, A. and Billen, J. 2010. Testes degeneration in ants: a histological study of Gnamptogenys bicolor. —Acta Zoologica (Stockholm) 92: 372–376. Sperm synthesis in the males of social Hymenoptera is not continuous, as the testes degenerate before the males become sexually active. This article presents the first histological study focusing on the degeneration of testes tissue, using adult males of the ant Gnamptogenys bicolor. At eclosion, spermatogenesis is still in process in the apical part of the testes, while the basal spermatocysts are all packed with mature sperm. During the second week after eclosion, the first signs of degeneration appear as small clear vacuoles inside the spermatocysts, interspersed between maturing sperm cells. Sperm starts migrating into the vasa deferentia shortly after. As spermatocysts void their contents into the vasa deferentia, the follicles start shrinking and losing their shape and the fibrillar capsule tissue gets looser. Cellular breakdown yields dark vacuoles of various density and large granular, multi-layered bodies.

Maintenance of adult porcine retina and retinal pigment epithelium in perfusion culture: Characterisation of an organotypic in vitro model

The purpose of this study was to characterise an ex-vivo adult porcine retina–retinal pigment epithelium (RPE) perfusion organ culture model. Fresh porcine full-thickness retina–RPE–choroid tissue samples were clamped into tissue carriers and mounted in two-compartment containers. The retinal and choroidal sides were continuously perfused with culture medium. pO2, [Na+], [K+], [Cl−], [glucose], [lactate], and pH were measured in the medium. Tissue samples were examined after 24h, 4, 7, and 10days in culture. The morphology of the retina and the RPE was examined by light and electron microscopy (LM, EM). The retinal cellular integrity was further examined by immunohistochemistry (Ki 67, GFAP, rhodopsin, synaptophysin, syntaxin, NF 200, TUNEL-test). Fresh porcine full-thickness retina–RPE–choroid tissue samples and tissue samples in static organ culture served as controls. LM, EM, and immunohistochemistry showed intact retinal and RPE cytoarchitecture kept in perfusion culture. Photoreceptor outer segments showed first signs of degeneration after 24h, significant signs of apoptosis and necrosis appeared in the retina after 4days in perfusion culture. Control tissue samples kept in static culture showed disintegration of the retinal cytoarchitecture after 4days in culture. The data show that adult porcine retina–RPE tissue can be maintained morphologically intact in perfusion organ culture for at least 10days. Although first signs of degeneration set in after 24h the structural preservation of the tissue in perfusion organ culture is superior to that in static culture. The perfusion culture model of the retina refines organotypic in vitro test systems and may help to reduce the number of necessary animal experiments in retina and RPE research. It offers new perspectives for the safety testing of substances designed for intraocular application.

Ultrastructural Studies of Embryo Abortion in Buckwheat (Fagopyrum esculentum) as a Heat-stress

Embryo abortion of Fagopyrum esculentum under high temperature stress was studied, firstly, at 1–3 d after pollination (DAP) with light and transmission electron microscope (TEM). The first sign of degeneration appeared at the subcellar level in the embryo sac within 2 DAP. Embryo development is significantly slowed. Almost all abortion is at the proembryonic, 8 to 24 cell stage. Embryo abortion is characterized by the appearance of large vacuoles in the embryo proper. The cytoplasm either is low in density or shows gradual condensation. And various changes occur in the abnormal cytoplasm: the cell walls expand, the ER becomes vesiculate, and osmiophilic deposits accumulate along the cell wall. The central cell degenerates to a greater degree. In particular, endosperm is absent or degenerates with either electron-dense condensed cytoplasm or dispersed cytoplasm in the early free-nuclear stage. The membrane system of organelles collapses. Dictyosomes and ER also become highly vesiculated and almost all organelles disperse within the central cell, while ribosome number is sharply decreased. In the aborted embryo sac, nucellar cells show a high degree of degeneration with condensed cytoplasm and vacuolation. As both of the nucellus and endosperm are heavily damaged by heat-stress of high temperature, this damage leads to the loss of normal endosperm function. Nutrients are not stored or transported to the developing embryo and, thus, embryo abortion is triggered before the embryo becomes autophytic.

Ultrastructure of Pollen Grains from Forced and Unforced Shrubs of Common Lilac

Forcing makes possible to induce plant flowering independently of the season. In lilac, high temperature is the factor that breaks deep dormancy. The deepest dormancy occurs between the end of October and the end of December. Depending on the depth of dormancy, the starting temperatures required for forcing are 37°C in November, 31°C in December, and 25°C in January–March. Under natural conditions, the temperature inducing the inflorescence bud breaking is 6°C, whereas 9°C and 13°C or more allow inflorescence elongation and flowering, respectively (Kronenberg, 1994). In the present work, the effect of high temperature at the beginning of the forcing cycle on the structure of developing pollen grains of common lilac was investigated. Pollen grains from the outdoor-grown (control) shrubs showed no signs of degeneration. They were spherical, three-colpate to colporoidate, and bicellular, and contained large numbers of lipid bodies. High temperatures at the early forcing cycle (November) resulted in the degeneration of most microspores. The first signs of degeneration (cytoplasm plasmolysis) were observed at the tetrad stage and in mature anthers; the microspores consisted only of the outer and inner sporopolenin layers.

Impact of pro‐oxidant agents on the morula‐blastocyst transition in bovine embryos

Exposing day 5 bovine morulae to reactive oxygen species induces a delayed degeneration of some blastocysts on day 8 post-insemination (pi) but without affecting the blastocyst rates. The aim of this study was to characterize the resisting and the degenerating population of blastocysts. The kinetics of degeneration of the embryos exposed to the two pro-oxidant agents: 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) and buthionine sulfoximine (BSO) was evaluated using time-lapse cinematography. With both agents the first signs of degeneration appeared at day 7.5 pi but the duration of the degeneration process was shorter in presence of AAPH than BSO (4.2 vs. 12.5 hr, ANOVA, P < 0.05). The resisting blastocysts derived from morulae with a larger diameter (mean diameter: 161 vs. 154 microm, ANOVA, P < 0.05) and showed an earlier cavitation (135 vs. 142 hpi, P < 0.05) than the degenerating ones. The profile of protein neosynthesis at day 7 was not affected by the treatment. The proportion of male embryos was more important in the resisting than in the degenerating population (70 vs. 55%, chi2, P < 0.05) especially when the stress was induced by AAPH. The quality of the resisting embryos, measured by the total cell number and the rate of apoptosis, did not seem to be affected when compared to control embryos. In conclusion, resistance to oxidative stress seems related to the kinetics of development and/or the sex of the embryos. Resisting embryos apparently display a quality similar to untreated embryos.

Morphological and ultrastructural changes occurring during degeneration of goat preantral follicles preserved in vitro

The present work has investigated the morphological and ultrastructural changes occurring during degeneration of goat preantral follicles preserved in vitro and showed quantitative data about the distribution of follicular degeneration types in the control and after preservation in coconut water solution or Braun–Collins solution at different temperatures (4, 20 or 39°C) and incubation times (4, 12 or 24 h). At the slaughterhouse, the pair of ovaries of each animal was divided into 19 fragments. One ovarian fragment was immediately fixed (control: Time 0). The other 18 fragments were randomly distributed in tubes containing 2 ml of coconut water or Braun–Collins solution at 4, 20 or 39°C and stored for 4, 12 or 24 h. Normal preantral follicles exhibited a healthy oocyte surrounded by one or more well-organized layers of granulosa cells. The ooplasm contained numerous rounded or elongated mitochondria with continuous mitochondrial membranes. Golgi complexes were rare. Both smooth and rough endoplasmic reticulum were observed, either as isolated aggregations or complex associations with mitochondria and vesicles. Degenerated preantral follicles in the control tissue exhibited pycnotic nuclei of the oocyte, vacuolated ooplasm and normal granulosa cells. This kind of degeneration also predominated significantly ( P<0.05) after preservation at 4°C. In contrast, after preservation at 20 or 39°C a significant predominance ( P<0.05) of preantral follicles showing a retracted oocyte and swollen granulosa cells was observed. These follicles showed large irregularity of the oocyte and nuclear outlines. The ooplasm exhibited moderate proliferation of the endoplasmic reticulum and mitochondria showed disappearance of most of the cristae and damage to the mitochondrial membrane. Some follicles had numerous vacuoles in the ooplasm. Granulosa cells were spread and a low density of organelles was observed. The alterations in follicular structure progressed with an increase of temperature from 20 to 39°C as well as with an increase of the incubation time from 4 to 12, or 24 h. In conclusion, the present study shows for the first time that initial proliferation of the endoplasmic reticulum and damage to mitochondria are the first signs of degeneration in goat preantral follicles during storage in vitro.

Neurotransmitter contents in the retina of RCS rat.

Retinitis pigmentosa is a hereditary disease characterized by gradually developing degeneration of photoreceptors. The Royal College of Surgeons (RCS) rat is an experimental model of retinitis pigmentosa. However, there is a paucity of information concerning neurotransmitter contents in the retina of RCS rats. Thus, we determined the retinal contents of neurotransmitters in RCS rats at 4 and 23 weeks postnatally and in age-matched congenic control rats. Dopamine (DA) and acetylcholine (ACh) were electrochemically measured by high-performance liquid chromatography (HPLC). Neuroactive amino acids, including gamma-aminobutyric acid (GABA) and taurine, were determined by means of an HPLC-precolumn derivatization method. Contents of DA, ACh, glutamate, aspartate and GABA in the retina of RCS rats 4 weeks postnatally were within normal ranges. At 23 weeks, the retinal contents of DA, glutamate and aspartate in the RCS rats were significantly lower than in the age-matched control rats, while the contents of ACh and GABA were unaffected even at this later stage. On the other hand, the retinal content of glycine in the RCS rats at 23 weeks was significantly higher than that in the age-matched control rats. It is interesting to note that the content of taurine in the RCS rats had already decreased at 4 weeks postnatally and the decrease was more marked at 23 weeks. The decrease in taurine content is probably the first sign of degeneration revealed by the retinal neurotransmitters of RCS rats.

Cochlear histopathology of the mutant bustling mouse, BUS/Idr.

The inner ear of mutant bustling mice, BUS/Idr, was examined histopathologically. LM examinations revealed an age-dependent degeneration of the auditory organ of Corti in BUS homozygotes, but not heterozygotes. Cochlear base-to-apex gradient in severity of the degeneration was noted. First signs of degeneration were found in the outer hair cells of the cochlear basal turn at about 3 weeks of age, followed by degeneration of the spiral ganglion cells which occurred slowly. As examined by SEM, stereociliary derangements of both the inner and outer hair cells were apparent in homozygotes as early as after 10 days. No normal arrays of stereocilia were found in homozygotes examined at 10 days through 6 months. The results of immunohistochemical examinations suggest that the sensory cells of the Corti's organ of homozygotes are structurally once normally innervated. No significant difference was found in the expression of protooncogene c-mos in the CNS between BUS homozygotes and control mice. We propose that BUS mice be categorized as a member of the so-called "waltzer-shaker" mutants group.

Scanning electron microscopical observation of the intramitochondrial body in the bovine corpus luteum during pregnancy and after parturition.

Large luteal cells of the bovine pregnant luteum can be characterized as steroid-producing cells. Mitochondria of these cells contained intramitochondrial bodies (IMB). The three-dimensional structure of the IMB and the degenerative process of luteal cells were as follows: 1) The IMBs were globular or oval, 0.1 to 1.5 microns in diameter. Their outer surfaces were coarse but their cut surfaces were uniform. Their outer surfaces changed from rough to smooth during pregnancy. 2) At the late stage of pregnancy, the large luteal cells lost their cytoplasmic processes, showing the first sign of degeneration at the cell level in such a way that their mitochondrial cristae transformed from tubular to laminar, and that they contained accumulated lipid droplets. 3) After parturition, the IMBs came out from degenerating large luteal cells, and were conveyed by lymphatic capillaries.

Cadmium‐induced changes in gill morphology of zebrafish, Brachydanio rerio (Hamilton–Buchanan), and rainbow trout, Salmo gairdneri Richardson

Freshwater zebrafish and brackish water rainbow trout were exposed to different concentrations of cadmium for up to 6 weeks. The gill morphology was examined by light and electron microscopy, and a morphometric analysis was performed. The morphometric study of the secondary lamellae revealed an increase in the portion exterior to the basal lamina, resulting in an increased diffusion distance, after exposure to cadmium concentrations of 10μg l−1 and above. In both species this was due to an increase in volume of the non‐tissue spaces of the secondary lamellar epithelium. Furthermore, the water space between neighbouring secondary lamellae was clearly reduced. Morphological examination revealed some gross alterations compared with control fish. These initially consisted in curling of the secondary lamellae and finally resulted in local teleangiectasia. Partial lifting of the secondary lamellar epithelium from the pillar cells resulted in large non‐tissue spaces which were invaded by leucocytes. The first sign of degeneration was observed in the chloride cells, which were characterized by a dispersed cytoplasm and a smooth apical plasma membrane.

Granulosa cell pyknosis in the dominant follicle of monkeys

One of the primary morphologic criteria used as the first sign of degeneration of an antral follicle is the presence of a pyknotic nucleus in granulosa cells lining the lumen. This study was undertaken to determine whether granulosa cells with a pyknotic nucleus are also present in the putative dominant follicle. Dominance was verified by elevations of estradiol either following luteectomy or during the later stages of the follicular phase of the menstrual cycle. Some pyknosis is normal even in the viable dominant follicle at cycle day 8 or 12. Therefore, when evaluating the morphologic status of a follicle, one should examine several areas to assure proper evaluation.

Functional and morphological consequences of kainic acid microinjections into a pontine respiratory area of the cat

The functional and morphological effects of kainic acid microinjections have been investigated in the nucleus parabrachialis medialis, a pontine respiration-related structure. Individual sensitivity of respiratory-modulated neurones located in the nucleus parabrachialis medialis to l-glutamate (an excitatory aminoacid analog to kainic acid) was demonstrated using microiontophoretic applications and extracellular recordings. After bivagotomy a small dose of kainic acid (0.5 μg in 0.5 μl) injected into one nucleus parabrachialis medialis induced irreversible apneustic breathing similar to that observed after electrocoagulation of the nucleus parabrachialis medialis. When the vagi were intact the same microinjection led to a complete cessation of spontaneous breathing of barbiturate-anaesthetized cats. Such irreversible effects were not reproduced in control experiments with comparable injections of l-glutamate or Ringer's solution in the nucleus parabrachialis medialis or with kainic acid injections outside the nucleus parabrachialis medialis. In another experimental series, after bivagotomy, large doses of kainic acid (4–6 μg in 8–12 microinjections on each side) were applied in a transverse plane caudal to the nucleus parabrachialis medialis; no apparent respiratory change was observed while electrocoagulation performed at the same level caused apneusis. The anatomical data obtained under light and electron microscopy after kainic acid microinjections have shown a rapid action upon various components of nervous tissue. There is a severe neuronal loss at the level of the injection site. Two hours after injection, somata exhibit the first signs of degeneration, but also axons and glia begin to react. At 20 h survival degeneration in all components continues to increase. The functional and morphological sequelae of kainic acid are discussed. Its usefulness as a neuropharmacological tool is confirmed but limits to its specificity have been found.

Tail anomaly lethal, Tal: A new mutant gene in the rat

A new hereditary tail anomaly (gene symbol Tal) in rats was found in the course of teratological studies with trypan blue. The characteristic feature of the tail anomaly was a short and kinked tail. The genetic analysis indicated that the tail anomaly was caused by an autosomal dominant gene and the homozygotes were lethal in the prenatal stage. The first sign of degeneration in the homozygous embryo appeared in the late egg cylinder stage. The phenotype of this mutant is similar to that of T-locus mutants in mice.

Regression of the larval opisthonephros during metamorphosis of the sea lamprey, Petromyzon marinus L.

The opisthonephric kidney of larval anadromous sea lamprey, Petromyzon marinus L., undergoes a programmed regression during metamorphosis. Degeneration is initiated in the anterior end of each kidney and progresses posteriorly until the kidneys are reduced to short, pigmented strands by the end of metamorphosis. The first sign of degeneration in both the epithelium of the renal corpuscles and the tubules is a folding of the basal lamina. Autolysis then occurs throughout the entire epithelium of the nephron with the gradual accumulation of larger and greater numbers of acid phosphatase-containing autophagic vacuoles, cytosomes, and myelin figures. Cytoplasmic debris and electron-dense material accumulates in the tubular lumina and in the urinary space. Although no definitive evidence is provided for the method of removal of the tubular epithelium, macrophages play a large part in the phagocytosis of the components of the renal corpuscle. Mesangial cells appear to engulf debris from the capillaries while a second type of macrophage is involved in the destruction of podocytes and parietal epithelial cells. The method of programmed degeneration of the renal corpuscle closely resembles descriptions of the mammalian renal corpuscle in diseased conditions. The sole surviving element of the degeneration of the entire nephron epithelium is a pleated basal lamina. The regressing larval opisthonephros has potential as an alternative system for studying a normal developmental pattern such as tissue regression.

Damage to Reissner's membrane in the guinea-pig cochlea following acute atoxyl intoxication.

The ototoxic effects of the arsenic compound atoxyl has been earlier demonstrated by Anniko & Wersäll (1975) in the stria vascularis of the guinea pig cochlea. The aim of the present investigation was to study the morphological degeneration at the ultrastructural level after damaging the Reissner's membrane experimentally. In acute atoxyl intoxication the first signs of degeneration appear after approximately 12 hours. After 24 hours, the membrane may be markedly degenerated. Both the epithelial and mesothelial cells become vacuolized, the mitochondria lose their internal structure and become swollen, and lipid granules are found in the cytoplasm. Mesothelial cells are damaged to a lesser extent than the epithelial cells in the same specimen.

Damage to Reissner's Membrane in the Guinea-Pig Cochlea Following Acute Atoxyl Intoxication

The ototoxic effects of the arsenic compound atoxyl has been earlier demonstrated by Anniko & Wer-säll (1975) in the stria vascularis of the guinea pig cochlea. The aim of the present investigation was to study the morphological degeneration at the ultrastructural level after damaging the Reissner's membrane experimentally. In acute atoxyl intoxication the first signs of degeneration appear after approximately 12 hours. After 24 hours, the membrane may be markedly degenerated. Both the epithelial and mesothelial cells become vacuolized, the mitochondria lose their internal structure and become swollen, and lipid granules are found in the cytoplasm. Mesothelial cells are damaged to a lesser extent than the epithelial cells in the same specimen.

Fine structure and fluoride resistant acid phosphatase activity of electron dense sinusoid terminals in the substantia gelatinosa Rolandi of the rat after dorsal root transection.

Fluoride resistant acid phosphatase (FRAP) activity of the rat substantia gelatinosa Rolandi is confined to electron dense sinusoid terminals under normal conditions. Transection of dorsal roots or removal of dorsal root ganglia results in a rapid degeneration of more than half of the electron dense sinusoid axon terminals. First signs of degeneration ensue 20 hours after surgery; at the 24 hours state osmiophilic degeneration bodies develop that are translocated into glial elements in the course of the second postoperative day. At the same time, light microscopically visible FRAP-activity of the Rolando substance disappears. Electron histochemical investigations reveal that decreased enzyme activity is due to degeneration of FRAP-positive terminals. It is concluded that FRAP-positive terminals, representing the majority of electron dense sinusoids in the Rolando substance, are dorsal root collaterals; the origin of non-degenerating FRAP-negative electron dense terminals remains unknown for the time being.