Ultrastructural Pattern Research Articles

Ultrastructural Analysis of the Anterior Lens Epithelium in Cataracts Associated with Uveitis

Purpose: To investigate the transmission electron microscopic findings of lens epithelial cells (LECs) in patients with different subtypes of uveitis and to compare the findings with those in age-matched controls. Methods: In this prospective case-control study, the anterior lens capsules were taken from 47 eyes of 47 patients with uveitis of different subtypes (17 with Fuchs uveitis syndrome [FUS], 13 with ­Behçet’s uveitis, 10 with idiopathic uveitis, and 7 with herpetic keratouveitis) and from 15 eyes of 15 control patients. Results: In the FUS group, the LECs had homogeneous thickening and irregularity, with some small vacuoles and widespread, oval-shaped pigment clusters in some areas. In the Behçet uveitis group, there was evident thinning in the lens epithelium. The subepithelial tissue under the epithelium was thickened, and edematous areas were detected. In the idiopathic uveitis group, the LECs were thinner with small vacuoles, and the cubic structure of the LECs was transformed into a squamous one. Moreover, the LECs included some small vacuoles, similar to those in the FUS group. In the herpetic keratouveitis group, two prominent cell types were observed: (1) completely normal LECs and (2) degenerated-type LECs with pyknotic nuclei, condensation of chromatin, swelling in the cytoplasm, membrane ruptures, and intra­cytoplasmic inclusion bodies. In the control group, the LECs and all of their elements occurred in normal ultrastructural patterns, with the exception of a few small intraepithelial vacuoles, which were fewer in number and smaller than those in the FUS and idiopathic uveitis groups. Conclusion: The electron microscopic analysis of LECs of patients with different subtypes of uveitis revealed significant ultrastructural alterations, which may be related to the summation of oxidative stress and intraocular inflammation.

A Method for 3D Reconstruction and Virtual Reality Analysis of Glial and Neuronal Cells.

Serial sectioning and subsequent high-resolution imaging of biological tissue using electron microscopy (EM) allow for the segmentation and reconstruction of high-resolution imaged stacks to reveal ultrastructural patterns that could not be resolved using 2D images. Indeed, the latter might lead to a misinterpretation of morphologies, like in the case of mitochondria; the use of 3D models is, therefore, more and more common and applied to the formulation of morphology-based functional hypotheses. To date, the use of 3D models generated from light or electron image stacks makes qualitative, visual assessments, as well as quantification, more convenient to be performed directly in 3D. As these models are often extremely complex, a virtual reality environment is also important to be set up to overcome occlusion and to take full advantage of the 3D structure. Here, a step-by-step guide from image segmentation to reconstruction and analysis is described in detail.

Activity and distribution pattern of enzymes in the in-situ pellicle of children

ObjectiveThis study investigated, for the first time, pellicle enzymes with respect to their activity, distribution and fluorescence pattern in children with different caries experience. DesignIn-situ pellicles were collected from 41 children (aged 4–6 years) with different caries status; 17 of them were caries-free (dmf = 0), 12 had dental restorations but no current caries (dmf ≥ 2) and 12 had at least two carious lesions (dmf ≥ 2). Bovine enamel samples were fixed on individual upper jaw braces for pellicle formation. After 30 min of intraoral exposure, the pellicle and saliva samples were analysed for the activities of amylase, lysozyme, peroxidase and glucosyltransferase (GTF). The distribution of these enzymes, including GTF-isoforms B, C and D, and the pellicle ultrastructure were examined by gold-immunolabelling and transmission electron microscopy (TEM). Furthermore, interactions between pellicle enzymes and adherent bacteria were visualised using combined fluorescence and immunofluorescence labelling. ResultsThere were no significant differences in the pellicle enzyme activities between the study groups. TEM analysis revealed the absence of GTF C and D in the pellicle of caries-active children. Amylase, peroxidase and GTF-isoforms showed a random distribution within the pellicle layer; lysozyme was found in the form of clusters. A similar ultrastructural pattern was observed for all subjects. Fluorescence labelling technique enabled visualisation of all enzymes, except for GTF B. ConclusionPellicle enzyme activities and ultrastructure are not associated with children’s caries status. Further investigation is needed to assess the influence of individual GTF-isoforms on caries susceptibility in children.

Ultrastructural organization of NompC in the mechanoreceptive organelle of Drosophila campaniform mechanoreceptors

Mechanoreceptive organelles (MOs) are specialized subcellular entities in mechanoreceptors that transform extracellular mechanical stimuli into intracellular signals. Their ultrastructures are key to understanding the molecular nature and mechanics of mechanotransduction. Campaniform sensilla detect cuticular strain caused by muscular activities or external stimuli in Drosophila Each campaniform sensillum has an MO located at the distal tip of its dendrite. Here we analyzed the molecular architecture of the MOs in fly campaniform mechanoreceptors using electron microscopic tomography. We focused on the ultrastructural organization of NompC (a force-sensitive channel) that is linked to the array of microtubules in these MOs via membrane-microtubule connectors (MMCs). We found that NompC channels are arranged in a regular pattern, with their number increasing from the distal to the proximal end of the MO. Double-length MMCs in nompC29+29ARs confirm the ankyrin-repeat domain of NompC (NompC-AR) as a structural component of MMCs. The unexpected finding of regularly spaced NompC-independent linkers in nompC3 suggests that MMCs may contain non-NompC components. Localized laser ablation experiments on mechanoreceptor arrays in halteres suggest that MMCs bear tension, providing a possible mechanism for why the MMCs are longer when NompC-AR is duplicated or absent in mutants. Finally, mechanical modeling shows that upon cuticular deformation, sensillar architecture imposes a rotational activating force, with the proximal end of the MO, where more NOMPC channels are located, being subject to larger forces than the distal end. Our analysis reveals an ultrastructural pattern of NompC that is structurally and mechanically optimized for the sensory functions of campaniform mechanoreceptors.

Co-existing colloidal phases of human duodenal aspirates: Intraindividual fluctuations and interindividual variability in relation to molecular composition

We investigated the ultrastructural pattern of colloidal phases in human duodenal fluids. Aspirates were collected from three volunteers in both fasted and fed nutritional states. Analysis methods comprised the combination of asymmetric flow field-flow fractionation (AF4) and multi-angle laser light scattering (MALLS). Furthermore, dynamic light scattering (DLS) and diffusion-ordered NMR spectroscopy (DOSY-NMR) were employed as alternative analytical approaches for comparison.By AF4/MALLS, up to four, and in some cases up to five distinct co-existing fractions could be differentiated in the sub-micron size-range, which, in accordance with a previous study (Elvang et al., 2018), may be assigned to three main types, namely small bile salt micelles, intermediate size mixed bile salt/phospholipid micelles and large phospholipid aggregates / vesicles. Although more or less the same colloidal phases were found to co-exist in all aspirates, their prevalence was found to vary, both over time and between the three individual human volunteers. Any uniform changes of patterns of colloidal phases over time, however, could not be identified. On the other hand, prevalence of specific colloidal phases was identified for aspirates of individual volunteers, which correlated reasonably well with the prevalence of certain lipid species in their molecular composition. It remains to be investigated whether such prevalence of specific colloidal phases influences drug solubilizing capacity as well as drug absorption. If so, this may help to better understand the substantial inter-individual variability seen in many drug absorption profiles.

Ultrastructural patterns of photoacclimation and photodamage to photosynthetic algae cell under environmental stress.

In oxygenic phototrophs including unicellular algae, acclimation to and damage by diverse environmental stresses induce profound changes in the ultrastructural organization of the cell. These alterations reflect acclimation of the photosynthetic apparatus to unfavorable conditions (mainly reduction of the chloroplast and its membranal system) and rewiring of the photo-fixed carbon fluxes in the cell. These changes, eventually pursuing mitigation of the photooxidative damage risk, are manifested by the formation of diverse carbon-rich inclusions. Although the physiological and molecular basis of these processes are well understood, the ultrastructural manifestations of the stress responses are often fragmented and frequently controversial. This minireview attempts to generalize on the ultrastructural patterns accompanying stresses in the photosynthetic cell, involving the concerted rearrangements of its assimilatory and storage compartments. The changes characteristic of normal functioning and emergency reduction of the chloroplast thylakoids under harsh stress are also addressed. Special attention is paid to the manifestations of the engagement of photoprotection via active (energy-dependent non-photochemical quenching) and passive mechanisms (e.g. optical shielding by secondary carotenoids). We also underline the potentially important role of autophagy-like processes and provide a more integral view of ultrastructural rearrangements under stress.

The androgenic gland in male morphotypes of the Amazon River prawn Macrobrachium amazonicum (Heller, 1862)

Sexual differentiation and primary and secondary sexual characteristics in male crustaceans are modulated by hormones produced in the androgenic gland (AG). The AG is also responsible for the determination of morphotypes in caridean shrimps, such as Macrobrachium amazonicum that shows four morphotypes: translucent claw (TC), cinnamon claw (CC), green claw 1 (GC1) and green claw 2 (GC2). Here, we verified the anatomical, histological and ultrastructural characteristics of the AG in different morphotypes of this species with both amphidromous and hololimnetic life cycles. In submissive morphotypes (TC and CC), the AGs are reduced and concentrated in the terminal expansion of the distal portion of vasa deferentia (DVD), the ejaculatory ducts (ED). In dominant morphotypes (GC1 and GC2) these glands lie along the DVD and ED. Two morphological stages (I and II) were recorded for AG cells. In submissive morphotypes stage I cells predominated in the AGs, while in dominant morphotypes stage II cells were more common. AG cells in both stages were positive for proteins, confirming the protein nature of the secreted hormone. Stage I cells have abundant rough endoplasmic reticulum (RER) with numerous parallel cisternae, whereas in stage II cells, the cisternae of RER are highly dilated. Stage II cells do not produce secretory granules, but they undergo hypertrophy and the hormone release to hemolymph probably occurs by holocrine secretion. The AGs in TC, GC1 and GC2 morphotypes increase as the animals grow and are larger in GC1 males. On the other hand, AGs decrease in the CC morphotype as the animal grows. These differences are related to the type of reproductive strategy adopted by each morphotype. In M. amazonicum, the AGs show the same morphological, histochemical and ultrastructural patterns between the different life history populations.

Morphological and ultrastructural changes in the placenta of the diabetic pregnant Egyptian women

Diabetes mellitus (DM) is a chronic metabolic disease in which the body fails to produce enough insulin or increased tissue resistance to insulin. The diabetes may have profound effects on placental development and function. This study was designed to detect the placental changes in pregnancy associated with DM comparing these changes with normal placenta. The study was carried out on sixty full-term placentae; divided into three equal groups; control group (group I): placentae of normal pregnancy, uncontrolled diabetes (group II): placentae from pregnant women whose blood glucose is poorly controlled during pregnancy. Controlled diabetes (group III): includes placentae from diabetic women whose blood glucose is controlled during pregnancy. The placentae from group II tend to be heavier and exhibited immaturity of villi, villous edema, fibrosis, excessive syncytial knots formation and infarctions. In addition to, fibrinoid necrosis, increased thickness of vasculosyncytial membrane, syncytial basement membrane, microvillous abnormalities and vascular endothelial changes were demonstrated. The syncytial multivesicular knots were present in placentae of group II. The nuclei within these syncytial knots display condensed chromatin, either dispersed throughout the nucleus or in the form of dense peripheral clumps with and numerous cytoplasmic vacuoles. The syncytial basement membrane showed focal areas of increase in its thickness and irregularity. Villous cytotrophoblasts showed increased number and activity in the form of numerous secretory granules, abundant dilated RER, larger distorted mitochondria. Villous vessels showed various degrees of abnormalities in the form of endothelial cell enlargement, folding, thickening and protrusion of their luminal surfaces into vascular lumen making it narrower in caliber. In placentae of group III, most of these abnormalities decreased. In most of placentae of group III, the VSM appeared nearly normal in thickness and showed nearly normal composition of one layer of syncytiotrophoblastic cells, one layer of smooth, regular capillary endothelium and the space between them. Mild microvillous abnormalities were noted in few placentae as they appeared short and blunted with mild decrease in their number per micron. The electron picture of syncytial knots appeared nearly normal containing aggregations of small, condensed hyperchromatic nuclei, minimal vacuoles could be seen in the cytoplasm of syncytial knots. Syncytial basement membrane appeared regular and nearly normal in its thickness and composition coming in direct contact with fetal blood capillaries but mild abnormalities were noted in the basement membrane in few placentae as increased its thickness and deposition of fibers or fibrinoid. Regarding cytotrophoblasts in the terminal villi of placentae with controlled diabetes, these cells appeared nearly normal. They were scattered beneath the syncytium and were active containing mitochondria, rough endoplasmic reticulum, free ribosomes and a large nucleus with fine dispersed chromatin. The vascular ultrastructural pattern in terminal villi of placentae of this group showed no significant abnormalities and was normally distributed in the villous tree. The luminal surface of the vascular endothelium appeared regular smooth in the majority of placentae of this group. The endothelial cells appeared connected to each other with tight junctions. It could be concluded that whether if long-term diabetes is controlled or not, placentae of diabetic mother showed a variety of significant histological structural changes seen more frequently than in the placentae of pregnant women without diabetes.

Extrafloral nectaries of four varieties of Chamaecrista ramosa (Vogel) H.S.Irwin & Barneby (Fabaceae): anatomy, chemical nature, mechanisms of nectar secretion, and elimination.

Considering the importance of extrafloral nectaries (EFNs) in Fabaceae, the objectives of this research were to analyze (1) the anatomical and histochemical characteristics of the EFNs of Chamaecrista ramosa var. ramosa, C. ramosa var. curvifoliola, C. ramosa var. parvifoliola, and C. ramosa var. lucida and (2) the ultrastructure of the EFNs of C. ramosa var. ramosa. Standard techniques in plant anatomy and transmission electron microscopy were used. The anatomical analyses confirmed the characteristics described for extrafloral nectaries, evidencing three well-defined regions: epidermis, nectariferous, and subnectariferous parenchymas. Carbohydrates, proteins, pectins/mucilages, and lipids were detected by histochemical analyzes in all varieties. The ultrastructure of the EFNs of C. ramosa var. ramosa allowed the observation of microchannels at the external periclinal cell walls of the epidermis covering the secretory region. The nectariferous and subnectariferous parenchyma cells have periplasmic spaces, large plastids containing starch grains and plastoglobules, mitochondria, developed endoplasmic reticulum, large vacuoles with electron-dense contents, and membrane residues may be associated with the vacuole, suggesting the occurrence of autophagic processes. The anatomical, histochemical, and ultrastructural patterns revealed characteristics that confirm the glands of C. ramosa as extrafloral nectaries and suggest the eccrine mechanism of secretion.

Palynotaxonomy of the genus Gladiopappus (Dicomeae, Asteraceae) with special emphasis on the exine ultrastructure and mesoapertures

The pollen morphology of Gladiopappus vernonioides was studied with transmission (TEM) and scanning (SEM) electron microscopy and with light microscopy (LM). An Anthemoid pattern of exine ultrastructure was found. The pollen morphology of Gladiopappus supports the inclusion of this genus in the tribe Dicomeae and subtribe Dicominae but not in the Mutisieae s.str. The apertural system of G. vernonioides includes a mesoaperture that intersects the foot layer and the upper layer of the endexine, a condition already pointed out for several tribes of Asteroideae (Helenieae, Gnaphaliinae, Heliantheae, Inuleae, Senecioneae) and Carduoideae (Cardueae, Dicomeae). It is suggested that the existence of an intermediate aperture could characterize the apertural system of the Asteraceae as a synapomorphy.

Description of an Intracellular Stage in the Experimental Infections of Albino Mice with a Venezuelan Isolate of Trypanosoma Evansi Using Scanning and Transmission Electron Microscopy Techniques

In Venezuela Trypanosoma evansi is responsible for trypanosomosis that affects equines, canines, bovines and wild animals such as capybaras. The pathology of the infections by this monomorphic trypanosome has been extensively studied by different authors in experimental and field conditions at level of light and electron microscopy. The aim of this study is to provide additional evidences about the development of an intracellular stage during experimental infections of albino mice with a Venezuelan isolated from Apure state. Samples of different organs from mice experimentally infected with 104 trypanosomes were prepared for transmission and scanning electron microscopy. Results show the presence of T. evansi in the lumen of blood vessels and interacting with endothelial cells, Küpffer cells, macrophages, lymphocytes and neutrophils. A frequent finding was the detection of intracellular trypomastigotes in the cytoplasm of normal looking and necrotic cells of the adrenal cortex, liver, capillaries and spleen. Despite most of the intracellular trypomastigotes observed, presented the ultrastructural feature of trypomastigotes from subgenus Trypanozoon, only a very few number of trypanosomes showed an ultrastructure compatible with an epimastigote-like. Most of trypanosomes presented a normal ultrastructure, however ultrastructural patterns suggestive of apoptosis could also be evidenced. Results are discussed in the context of their impact in the diagnosis, treatment of the disease, evasion of immune system, immunosuppression as well as the persistence and prevalence of T. evansi in natural hosts.

Ultrastructure of mature spermatozoa of three Bucephalidae (Prosorhynchus longisaccatus, Rhipidocotyle khalili and Bucephalus margaritae) and phylogenetic implications.

We describe here the mature spermatozoa of three species of bucephalids, namely Bucephalus margaritae, Rhipidocotyle khalili and Prosorhynchus longisaccatus. This study provides the first ultrastructural data on the genera Bucephalus and Rhipidocotyle and enabled us to confirm the model of the mature spermatozoon in the Bucephalinae. The spermatozoon exhibits two axonemes with the 9 + “1” pattern of the Trepaxonemata, one of which is very short, lateral expansion, external ornamentation of the plasma membrane located in the anterior extremity of the spermatozoon and associated with cortical microtubules, spine-like bodies, a mitochondrion, and a nucleus. The maximum number of cortical microtubules is located in the anterior part of the spermatozoon. However, more studies are needed to elucidate if spine-like bodies are present in all the Bucephalinae or not. In the Prosorhynchinae, the mature spermatozoon exhibits a similar ultrastructural pattern. Some differences are observed, particularly the axoneme lengths and the arrangement of the spine-like bodies. The posterior extremity of the spermatozoon in the Bucephalinae exhibits only the nucleus, but prosorhynchines have microtubules.

Ultrastructural Patterns of Interactions between Murine Lung Macrophages and Yeast Cells of Cryptococcus neoformans Strains with Different Virulence

This article presents the ultrastructural patterns of interactions between the murine lung macrophages and cells of low- (RKPGY-881, -1165, -1178) and high-virulence (RKPGY-1090, -1095, -1106) strains of Cryptococcus neoformans at the seventh post-experimental day. It was found that if macrophages ingest living yeast cells, the latter can: 1) become completely free from polysaccharide capsules, after that their contents undergo lysis, and cell wall debris are extruded from the macrophage (first scenario); 2) become partly free from their capsules, destroy the phagosomal plasma membrane and induce destructive processes inside the macrophage causing their death (second scenario); or 3) not lose their capsules and localize inside macrophage in latent state (third scenario). Macrophages can also ingest senescent and dead C. neoformans cells surrounded by capsules that are lost at the ingesting and phagosome stages (fourth scenario). The study revealed the dependence of cell-mediated immunity on the stage of development of ingested C. neoformans yeast cells. Here we describe a new mechanism of capsular polysaccharide elimination of C. neoformans yeast cells by murine macrophages.

Electron microscopic changes of detrusor in benign enlargement of prostate and its clinical correlation.

ABSTRACTAims:To study the ultra structural changes in bladder musculature in cases of BPE and their clinical relevance.Material and Methods:In this descriptive longitudinal, controlled, observational study patients were enrolled into three groups, group 1, group 2A and group 2B. Control group (group-1) consisted of age matched normal male patients, who underwent surveillance or diagnostic cystoscopy for microscopic hematuria or irritative symptoms. Case group (group-2) comprised of patients with BPE, undergoing TURP. Case group (group-2) was further classified into: Category 2A (patients not on catheter) and category 2B (patients on catheter). All relevant clinical parameters like IPSS, prostate size, Qmax, PVR were recorded. Cystoscopy and bladder biopsy were performed in all patients. Various ultrastructural parameters like myocytes, fascicular pattern, interstitial tissue, nerve hypertrophy and cell junction pattern were analyzed under electron microscope and they were clinically correlated using appropriate statistical tests.Results:Control group had significant difference as compared to case group in terms of baseline parameters like IPSS, flow rate and prostate size, both preoperatively and postoperatively, except for PVR, which was seen only preoperatively. There was statistically significant difference in ultrastructural patterns between case and control group in all five electron microscopic patterns. However, no significant difference was found between the subcategories of case groups.Conclusions:BPE is responsible for ultra structural changes in detrusor muscle and these changes remain persistent even after TURP. Nerve hypertrophy, which was not thoroughly discussed in previous studies, is also one of the salient feature of this study.

The ultrastructural alterations in the lens capsule and epithelium in eyes with traumatic white cataract.

To demonstrate the morphological and physiological characteristics of lens epithelial cells (LECs) in patients with traumatic cataract using transmission electron microscopy (TEM) to further understand penetrating ocular injury-induced cataract morphology and epithelial repair mechanisms involved at a cellular level. This is a prospective international study. Sixteen eyes of 16 consecutive patients who were diagnosed as traumatic white cataracts following the anterior lens capsule perforation and 13 eyes of 13 patients with idiopathic posterior subcapsular cataract were included to the study. The anterior lens capsules (aLCs: basement membrane and associated LECs) were obtained from cataract surgery and prepared for TEM. Two prominent cell types were observed in all aLCs of the traumatic cases: degenerated type LECs having variable sized intraepithelial vacuoles close to injury site and normal appearing LECs having an euchromatic nucleus distant from the injury site. In control group, the LECs and all their elements were in normal ultrastructural pattern except some small intraepithelial vacuoles, which were fewer and smaller than the vacuoles in the degenerated LECs of the traumatic group. The ultrastructural findings of our cases support that traumatically induced dysfunction of the lens epithelium may lead to an edema in superficial cortical lens fibers that subsequently undergo degeneration and produce a localized zone of vacuolization.

Enzymology and Ultrastructure of the in situ Pellicle in Caries-Active and Caries-Inactive Patients

Aim: The present study aimed to evaluate the impact of caries activity on the key enzymes and the ultrastructure of the in situ pellicle. Methods: Pellicle formation was performed on bovine enamel slabs. Intraoral exposure (3, 30, and 120 min) was accomplished by 14 caries-active (DMFS: 22.7 ± 12.1) and 13 caries-inactive (DMFS: 1.5 ± 1.8) individuals. The enzyme activities (lysozyme, peroxidase, α-amylase, glycosyltransferase [GTF]) in the in situ pellicle and resting saliva of all participants were analyzed directly after oral exposure. In addition, a simultaneous visualization of these enzymes, extracellular glucans, and adherent bacteria was carried out. Fluorescent patterns were analyzed with fluorescence labeling and 4′,6-diamidino-2-phenylindole/concanavalin A staining. In addition, the distribution of GTF B, C, and D and the ultrastructure of the pellicle were examined by gold immunolabeling and transmission electron microscopy with selected samples. Results: Enzyme activities of amylase, peroxidase, lysozyme, and GTF were detected on all enamel slabs in an active conformation. Neither exposure time nor caries activity had an impact on the enzyme activities. Gold immunolabeling indicated that the pellicle of caries-active subjects tends to more GTF D molecules. The pellicles of caries-inactive and -active individuals revealed a similar ultrastructural pattern. Conclusion: The enzyme activities as well as the pellicle's ultrastructure are of high similarity in caries-active and -inactive subjects. Thereby, oral exposure time has no significant influence. This reflects a high uniformity during the initial phase of bioadhesion (3-120 min) concerning enzymatic functions. However, there is a tendency towards more GTF D in caries-active individuals.

Collagenous Ultrastructure of the Discoid Meniscus: A Transmission Electron Microscopy Study

Background: The collagen ultrastructure of the discoid lateral meniscus (DLM) has not been precisely defined. Purpose: To investigate the ultrastructure of the DLM, focusing on its collagen fibers, and to compare the collagen net architecture between intact and torn DLMs using the Collagen Meniscal Architecture (CMA) scoring system. Study Design: Descriptive laboratory study. Methods: Thirty specimens were taken from 30 patients with a diagnosis of a complete DLM using a 1-piece technique. The collagen ultrastructure of the DLMs was assessed with transmission electron microscopy. To evaluate the meniscal ultrastructure, the degree of collagen disruption, intrafibrillar edema, loss of banding, degree of collagen packing, and fibril size variability were assessed and graded from 1 (normal) to 3 (severe disarray) according to the CMA scoring system. The DLM specimens were divided into 3 groups according to the intrasubstance tear: the intact group (group I) had no tear; the simple tear group (group S) had a radial, longitudinal, or horizontal tear; and the complicated tear group (group C) had a complicated horizontal tear. Intact normal meniscus specimens (group N) were used as the control group. Results: There were 10 specimens in group I, 8 in group S, 12 in group C, and 13 in group N. In group I, there were 5 grade 1 and 5 grade 2 menisci; group S had 2 grade 1, 3 grade 2, and 3 grade 3 menisci; group C had 1 grade 1, 4 grade 2, and 7 grade 3 menisci; and group N had 4 grade 1, 7 grade 2, and 2 grade 3 menisci. A significant difference in the CMA score was observed between the 4 groups (P = .009). The median CMA score was significantly lower in group I (2; range, 1-4) than in group S (4; range, 2-7) (P = .041) and group C (4.25; range, 1.5-7) (P = .018). No significant difference was found between groups S, C, and N. Conclusion: Variability existed in the collagen ultrastructure of the DLM, and some DLMs showed a nearly normal ultrastructural pattern. The degree of density and disorganization of the collagen architecture in the DLM was related to the tear. Clinical Relevance: The study results might provide a histological background for partial meniscectomy in the treatment of a symptomatic DLM.

Altered Mitochondrial Anatomy of Trigeminal Ganglia Neurons in Diabetes.

Neurons from sensory ganglia are exposed to oxidative attack in diabetes. Altered mitochondrial morphologies are due to impaired dynamics (fusion, fission) and to cristae remodeling. This study aimed to evaluate using transmission electron microscopy mitochondrial changes in diabetic trigeminal ganglia suggestive for ignition of apoptosis, in absence of "classical" morphological signs of apoptosis. We used samples of trigeminal ganglia (from six type 2 diabetes human donors and five streptozotocin (STZ)-induced diabetic rats). In human diabetic samples we found three main distributions of mitochondria: (a) small "dark" normal mitochondria, seemingly resulted from fission processes; (b) small "dark" damaged mitochondria, with side-vesiculations (single- and double-coated), large matrix vesicles and cytosolic leakage of reactive species, mixed with larger "light" mitochondria, swollen, and with crystolysis; (c) prevailing "light" mitochondria. In STZ-treated rats a type (c) distribution prevailed, except for nociceptive neurons where we found a different distribution: large and giant mitochondria, suggestive for impaired mitochondrial fission, mitochondrial fenestrations, matrix vesicles interconnected by lamellar cristae, and mitochondrial leakage into the cytosol. Thus, the ultrastructural pattern of mitochondria damage in diabetic samples of sensory neurons may provide clues on the initiation of intrinsic apoptosis, even if the classical morphological signs of apoptosis are not present. Further studies, combining use of biochemical and ultrastructural techniques, may allow a better quantification of the degree in which mitochondrial damage, with membrane alterations and cytosolic leaks, may be used as morphological signs suggesting the point-of-no return for apoptosis. Anat Rec, 299:1561-1570, 2016. © 2016 Wiley Periodicals, Inc.

A novel ultrastructure on the corneocyte surface of mammalian nasolabial skin

In many mammals, the skin of the rhinarium includes a thick epidermal layer. The skin surface can be smooth but can also display a structure formed of domes, ridges, and polygonal areas: a dermatoglyphic or rhinoglyphic pattern. Each structure consists of an easily visible, large area of the epidermis. The abdominal epidermis may or may not have a dermatoglyphic pattern. The abdominal skin examined in our study had no pattern and was consequently unstructured and smooth. The ultrastructural surface pattern is formed in the granular and corneous regions of nasal epidermis by desmosome protrusions projecting into adjacent keratinocytes. Complete retraction of the keratinocyte protrusions with desmosomes in the abdominal epidermis creates an unstructured, smooth surface. The cornification process differs morphologically in nasolabial and abdominal skin. In this study, we report a novel structure in the nose skin. It is related only to the surface of a single corneocyte (keratinocyte) and consists of submicrometer pores or furrows, an ultrastructure pattern. It is not related to the rhinoglyphic pattern. The nose skin can thus have 2 unrelated patterns. This structure seems to be widespread among the Mammalia. We suggest the function of the structure is to keep the rhinarium evenly moist.

Effects of combined exposure to aluminum chloride and γ-radiation on histological and ultrastructure of intestinal Paneth cells

PurposeThe use of aluminum chloride (AlCl3) as in purification of water and the exposure to ionizing radiation (IR) in therapeutic treatments are believed to be relatively safe. However, their combined effects remain unclear. The aim of the present study is to investigate the effects of concomitant exposure to aluminum chloride and gamma radiation on the histological and ultra-structural pattern of the crypt Paneth cells (PC) of the small intestine in albino rats. Materials and methodsForty male albino rats were divided randomly into four groups (n = 10). Group 1: Control group, Group 2: Aluminum treated group (Rats received a daily a dose of 0.5 mg of AlCl3 per kg of body weight/day), Group 3: γ-Radiation group (rats are exposed to a total dose of 8 Gy in 4 fractions of 2 Gy/week) and Group 4 Rats exposed to AlCl3 and exposed to γ-Radiation. Animals were sacrificed after 4 weeks, one day after the last radiation dose. ResultsHistological and ultra-structural studies in small intestine showed that exposure to γ-rays induced alterations in PC including apoptotic nuclei, presence of injury in secretory granules and completely damaged organelles at the sites of bacterial translocation in the crypt of lumens. Aluminum exposure during irradiation potentiate the damage notified by abnormal PC morphology, dilation the crypt's lumen and erosions of its villi with increased apoptosis in the crypt cells and appearance of homogenously electron-lucent granules. ConclusionsIt is concluded that concomitant exposure to aluminum and IR increased detrimental structural changes in PC of rat intestine due to their combined effect. It is thus recommended to limit the intake of aluminum when human are at risk of over exposure to ionizing radiation.