515 research outputs found
The synovial surface of the articular cartilage
The articular cartilage has been the subject of a huge amount of research carried out with a wide array of different techniques. Most of the existing morphological and ultrastructural data on the this tissue, however, were obtained either by light microscopy or by transmission electron microscopy. Both techniques rely on thin sections and neither allows a direct, face-on visualization of the free cartilage surface (synovial surface), which is the only portion subject to frictional as well as compressive forces. In the present research, high resolution visualization by scanning electron microscopy and by atomic force microscopy revealed that the collagen fibrils of the articular surface are exclusively represented by thin, uniform, parallel fibrils evocative of the heterotypic type IX-type II fibrils reported by other authors, immersed in an abundant matrix of glycoconjugates, in part regularly arranged in phase with the D-period of collagen. Electrophoresis of fluorophore-labeled saccharides confirmed that the superficial and the deeper layers are quite different in their glycoconjugate content as well, the deeper ones containing more sulfated, more acidic small proteoglycans bound to thicker, more heterogenous collagen fibrils. The differences found between the synovial surface and the deeper layers are consistent with the different mechanical stresses they must withstand
Type 2 Diabetes Mellitus and COVID-19: A Narrative Review
The pandemic of coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has involved more than one hundred million individuals, including more than two million deaths. Diabetes represents one of the most prevalent chronic conditions worldwide and significantly increases the risk of hospitalization and death in COVID-19 patients. In this review, we discuss the prevalence, the pathophysiological mechanisms, and the outcomes of COVID-19 infection in people with diabetes. We propose a rationale for using drugs prescribed in patients with diabetes and some pragmatic clinical recommendations to deal with COVID-19 in this kind of patient
Atherosclerotic alterations in human carotid observed by scanning electron microscopy.
Atherosclerosis involves all the layers of the artery wall, but the events involving the intimal portion are fundamental to understand the evolution and gravity of lesions. This study shows that scanning microscopy is instrumental for better understanding the physiopathology of this disease
The assessment of dog welfare in the waiting room of a veterinary clinic
Veterinary visits are known to be stressful for many dogs. The aim of this study was to assess dog welfare in the waiting room of the veterinary clinic through a multi-modal, non-invasive approach. Forty-five dogs were each videoed for 3 min in the waiting room of a veterinary clinic where they went for a scheduled visit. The welfare of each dog was assessed using a thorough video analysis and two overall evaluations (low, medium and high stress); one performed by a veterinary behaviourist and one by the dog's owner. Two-thirds of dogs spent more than 20% of the time displaying at least one indicator of stress, and 53.3% showed four or more behavioural signs of stress. Assessments of stress by the behaviourist indicated that level of stress in the waiting room was high in 28.9% of cases. The agreement between owners' and behaviourist's overall evaluations was quite low. The behaviourist's evaluations were strongly correlated with the time spent by dogs showing signs of stress and moderately correlated with the number of displayed signs, whilst owners' evaluations were not closely correlated to those factors. Dogs rated as highly stressed by the behaviourist were more prone to display resistance (halting, refusing to budge) when moving from the waiting room to the consultation room. The results of this pilot study support the idea that the welfare of dogs in the veterinary waiting room is often impaired, and that owners are unable to accurately assess stress in their dogs in such situations
The combined cartilage growth – calcification patterns in the wing-fins of Rajidae (Chondrichthyes): A divergent model from endochondral ossification of tetrapods
The relationship between cartilage growth – mineralization patterns were studied in adult Rajidae with X-ray morphology/morphometry, undecalcified resin-embedded, heat-deproteinated histology and scanning electron microscopy. Morphometry of the wing-fins, nine central rays of the youngest and oldest specimens documented a significant decrement of radials mean length between inner, middle and outer zones, but without a regular progression along the ray. This suggests that single radial length growth is regulated in such a way to align inter-radial joints parallel to the wing metapterygia curvature. Trans-illumination and heat-deproteination techniques showed polygonal and cylindrical morphotypes of tesserae, whose aligned pattern ranged from mono-columnar, bi-columnar, and multi-columnar up to the crustal-like layout. Histology of tessellated cartilage allowed to identify of zones of the incoming mineral deposition characterized by enhanced duplication rate of chondrocytes with the formation of isogenic groups, whose morphology and topography suggested a relationship with the impending formation of the radials calcified column. The morphotype and layout of radial tesserae were related to mechanical demands (stiffening) and the size/mass of the radial cartilage body. The cartilage calcification pattern of the batoids model shares several morphological features with tetrapods' endochondral ossification, that is, (chondrocytes' high duplication rate, alignment in rows, increased volume of chondrocyte lacunae), but without the typical geometry of the metaphyseal growth plates
Immunological characteristics of non-intensive care hospitalized COVID-19 patients: A preliminary report
Abstract: The outbreak of coronavirus disease 2019 (COVID-19) is posing a threat to global health.
This disease has different clinical manifestations and different outcomes. The immune response
to the novel 2019 coronavirus is complex and involves both innate and adaptive immunity. In
this context, cell-mediated immunity plays a vital role in effective immunity against SARS-CoV-2.
Significant differences have been observed when comparing severe and non-severe patients. Since
these immunological characteristics have not been fully elucidated, we aimed to use cluster analysis
to investigate the immune cell patterns in patients with COVID-19 who required hospitalization but
not intensive care. We identified four clusters of different immunological patterns, the worst being
characterized by total lymphocytes, T helper lymphocytes CD4+
(CD4+
), T cytotoxic lymphocytes
CD8+
(CD8+
) and natural killer (NK) cells below the normal range, together with natural killer
lymphocyte granzyme < 50% (NK granzyme+
) and antibody-secreting plasma cells (ASCs) equal to 0
with fatal outcomes. In the worst group, 50% of patients died in the intensive care unit. Moreover,
a negative trend was found among four groups regarding total lymphocytes, CD4+
, CD8+ and B
lymphocytes (p < 0.001, p < 0.005, p < 0.000, p < 0.044, respectively). This detailed analysis of immune
changes may have prognostic value. It may provide a new perspective for identifying subsets of
COVID-19 patients and selecting novel prospective treatment strategies. Notwithstanding these
results, this is a preliminary report with a small sample size, and our data may not be generalizable.
Further cohort studies with larger samples are necessary to quantify the prognostic value’s weight,
according to immunological changes in COVID-19 patients, for predicting prognoses and realizing
improvements in clinical conditions
The collagenic architecture of human dura mater: Laboratory investigation
Object. Human dura mater is the most external meningeal sheet surrounding the CNS. It provides an efficient protection to intracranial structures and represents the most important site for CSF turnover. Its intrinsic architecture is made up of fibrous tissue including collagenic and elastic fibers that guarantee the maintenance of its biophysical features. The recent technical advances in the repair of dural defects have allowed for the creation of many synthetic and biological grafts. However, no detailed studies on the 3D microscopic disposition of collagenic fibers in dura mater are available. The authors report on the collagenic 3D architecture of normal dura mater highlighting the orientation, disposition in 3 dimensions, and shape of the collagen fibers with respect to the observed layer. Methods. Thirty-two dura mater specimens were collected during cranial decompressive surgical procedures, fixed in 2.5% Karnovsky solution, and digested in 1 N NaOH solution. After a routine procedure, the specimens were observed using a scanning electron microscope. Results. The authors distinguished the following 5 layers in the fibrous dura mater of varying thicknesses, orientation, and structures: bone surface, external median, vascular, internal median, and arachnoid layers. Conclusions. The description of the ultrastructural 3D organization of the different layers of dura mater will give us more information for the creation of synthetic grafts that are as similar as possible to normal dura mater. This description will be also related to the study of the neoplastic invasion
Correlative Microscopy Of Bone In Implant Osteointegration Studies.
Routine morphological analyses usually include investigations by light microscopy (LM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Each of these techniques provides specific information on tissue morphology and all the obtained results are then combined to give an in-depth morphological overview of the examined sample. The limitations of this traditional comparative microscopy lie in the fact that each technique requires a different experimental sample, so that many specimens are necessary and the combined results come from different samples. The present study describes a technical procedure of correlative microscopy, which allows us to examine the same bone section first by LM and then, after appropriate processing, by SEM or TEM. Thanks to the possibility of analyzing the same undecalcified bone sections both by LM and SEM, the approach described in the present study allows us to make very accurate evaluations of old/new bone morphology at the bone-implant interface
Comparison of minimally invasive parathyroidectomy under local anaesthesia and minimally invasive video-assisted parathyroidectomy for primary hyperparathyroidism: A cost analysis
Background: Primary hyperparathyroidism (PHPT) origins from a solitary adenoma in 70-95% of cases. Moreover, the advances in methods for localizing an abnormal parathyroid gland made minimally invasive techniques more prominent. This study presents a micro-cost analysis of two parathyroidectomy techniques. Patients and methods: 72 consecutive patients who underwent minimally invasive parathyroidectomy, video-assisted (MIVAP, group A, 52 patients) or "open" under local anaesthesia (OMIP, group B, 20 patients) for PHPT were reviewed. Operating room, consumable, anaesthesia, maintenance costs, equipment depreciation and surgeons/anaesthesiologists fees were evaluated. The patient's satisfaction and the rate of conversion to conventional parathyroidectomy were investigated. T-Student's, Kolmogorov-Smirnov tests and Odds Ratio were used for statistical analysis. Results: 1 patient of the group A and 2 of the group B were excluded from the cost analysis because of the conversion to the conventional technique. Concerning the remnant patients, the overall average costs were: for Operative Room, 1186,69 \u20ac for the MIVAP group (51 patients) and 836,11 \u20ac for the OMIP group (p<0,001); for the Team, 122,93 \u20ac (group A) and 90,02 \u20ac (group B) (p<0,001); the other operative costs were 1388,32 \u20ac (group A) and 928,23 \u20ac (group B) (p<0,001). The patient's satisfaction was very strongly in favour of the group B (Odds Ratio 20,5 with a 95% confidence interval). Conclusions: MIVAP is more expensive compared to the "open" parathyroidectomy under local anaesthesia due to the costs of general anaesthesia and the longer operative time. Moreover, the patients generally prefer the local anaesthesia. Nevertheless, the rate of conversion to the conventional parathyroidectomy was relevant in the group of the local anaesthesia compared to the MIVAP, since the latter allows a four-gland exploration
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