Dilated Capillaries Research Articles

Tetramethylpyrazine Attenuates Radiation-Induced Ototoxicity in a Rat Model

Introduction: Tetramethylpyrazine (TMP) is a chemical compound, which has been shown to possess numerous biological features such as anticoagulation, inhibition of platelet aggregation, anti-inflammation, capillary dilatation, improvement in microcirculation, and protection against reactive oxygen radicals. The aim of the present study was to investigate the protective effect of TMP against radiation-induced ototoxicity. Materials and Methods: 40 rats were divided into four groups. The first group was irradiated for 5 days. The second group received a single dose of 140 mg/kg/day intraperitoneal TMP given to the rats 30 min before radiotherapy (RT) for 5 days. The third group received a single dose of 140 mg/kg/day i.p. TMP for 5 days, whereas the fourth group was administered saline. All rats underwent distortion product otoacoustic emission (DPOAE) and auditory brainstem response measurements before and after the application. The temporal bulla of animals was removed for immunohistopathological examination. Results: Signal-noise ratio values were significantly decreased in the RT group for the frequencies of 2–32 kHz after RT (p < 0.05), whereas the difference was not significant in terms of pre- and posttreatment values for the other groups. Also in the RT group, the ABR thresholds were significantly increased after treatment. In H&E staining, the mean scores for outer hair cells (OHCs), stria vascularis (SV), and spiral ganglion (SG) injuries were significantly higher in RT and RT + TMP groups than in the other groups. The mean OHCs and SV injury scores were also significantly higher in the RT group than in the RT + TMP group (p < 0.05). The number of cochleas that showed cytoplasmic caspase-3 immunoreactivity in the OHC, SV, and SG was significantly higher in RT and RT + TMP groups than in the other groups. Conclusion: The findings of the present study suggest that TMP may have a therapeutic potential for preventing sensorineural hearing loss (SNHL) related to RT.

Acute toxicity of essential oils of Aloysia triphylla (L'Hér.) Britton, Lippia gracilis Schauer, and Piper aduncum L. in Colossoma macropomum (Cuvier, 1818).

The aim of this study was to determine the acute toxicity of the essential oils (EOs) of Aloysia triphylla, Lippia gracilis and Piper aduncum in juvenile tambaqui (Colossoma macropomum), and evaluate the possible histopathological alterations in their gills. For the acute toxicity tests, juvenile tambaqui (n=24/treatment) were distributed in six treatments with three replicates, which comprised the control and five EO concentrations of A. triphylla (60, 80, 100, 120 and 140 mg L-1), L. gracilis (35, 40, 45, 50 and 55 mg L-1) and P. aduncum (42.5, 45, 47.5, 50 and 52.5 mg L-1), with an exposure period of 4 h. The mortality rate and severity of damage to the tambaqui gills were proportional to the increase in the concentration of the EO, with LC50-4 h values estimated at 109.57 mg L -1 for A. triphylla, 41.63 mg L -1 for L. gracilis and 48.17 mg L -1 for P. aduncum. The main morphological damages observed in the gills of the tambaqui exposed to the three EOs, were Grade I: hypertrophy and hyperplasia of lamellar epithelial cells, lamellar fusion, epithelial detachment, capillary dilation and constriction, proliferation of chloride cells and mucosal cells and edema; in low frequency Grade II damage as epithelial rupture and lamellar aneurysm. Necrosis (Grade III damage) was observed only in gill lamellae exposed to P. aduncum EO (47.5, 50.0 and 52.5 mg L-1). Concentrations of EOs below LC50-4 h can be used sparingly, for short periods of exposure for the treatment of diseases in tambaqui breeding.

Thrombosis in hereditary hemorrhagic telangiectasia

Thrombosis in hereditary hemorrhagic telangiectasia

Persistent Generalized Cutis Marmorata Telangiectatica Congenita with Venectasia.

Persistent Generalized Cutis Marmorata Telangiectatica Congenita with Venectasia.

Management of small bowel angioectasias diagnosed during video capsule endoscopy.

Small bowel angioectasias (SBA) are vascular malformations consisting of thin-walled, dilated capillaries located in the gastrointestinal mucosa. They are responsible for 10% of all causes of gastrointestinal bleeding and 60% of small bowel bleeding pathologies. The diagnosis and management of SBA depend upon bleeding acuity, patient stability and patient characteristics. Small bowel capsule endoscopy is a relatively noninvasive diagnostic approach ideal for non-obstructed and hemodynamically stable patients. It is superior to computed tomography scans in visualizing mucosal lesions, such as angioectasias, as it provides mucosal views. Management of these lesions will depend on the patient's clinical condition and associated comorbidities, and very often consists of medical and/or endoscopic treatment delivered through small bowel enteroscopy.

Histopathological changes as tools to discriminate antemortem and post-mortem wounds in rats: prospective applications in forensic medicine

Wound age estimation is one of the chief exciting subjects in forensic medicine. It is substantial to determine the most likely accurate when wounds happened, whether during antemortem or post-mortem conditions. Moreover, histological change is a method that assists available parameters in determining the antemortem and post-mortem period. This study aims to observe the histopathological changes in induced wounds to determine when the injury occurred and whether the injury occurred during antemortem or post-mortem conditions. Thirty-nine rat wound skin biopsies were studied. All samples were taken in antemortem groups at 30, 60, 180, and 360 min, and in post-mortem groups within 30, 60, 180, and 360 min with control samples (unwounded group). The skin sections were seen by microscope to observe the changes in the following criteria: the ratio and distribution of the neutrophil and macrophage, congestion and dilatation of capillaries, and degree of autolysis. For the antemortem wounds, the number of neutrophils appeared at 30 minutes and sharply increased from 60 minutes after the wound. In addition, there was an increase in macrophages from 180 min after the wound. For the post-mortem wounds in all times examined, the degree of autolysis was the best criterion for knowing the wound timing. These results propose that histopathological changes can be used as a critical criterion for finding the time of wounds and comparing antemortem and post-mortem incisional wounds in forensic medicine.

Non-steroidal anti-inflammatory agents for treating cystoid macular edema following cataract surgery.

Non-steroidal anti-inflammatory agents for treating cystoid macular edema following cataract surgery.

ANGIOKERATOMA: A RARE MANIFESTATION

Angiokeratoma shows dilatation of capillaries in the upper dermis and it also shows some epidermal changes, like- hyperkeratosis, papillomatosis, and thickening of epidermis or acanthosis .Clinical presentation of angiokeratoma includes plaques over the skin of lower limbs, mostly on the buttocks or thigh. It is usually identified clinically but a definitive diagnosis is made only on histopathological examination.Adeeper biopsy of the lesion is empirically essential to make a concrete diagnosis as the characteristic changes seen in angiokeratoma, are limited to superficial dermis. Our case report has a 24 years old female presenting with unilateral, linear, bluish-black verrucous plaque on the back of left elbow.

Role of pericytes in the development of cerebral cavernous malformations.

Cerebral cavernous malformation (CCM) is caused by loss-of-function mutations in CCM1, CCM2, or CCM3 genes of endothelial cells. It is characterized by pericyte deficiency. However, the role of pericytes in CCMs is not yet clarified. We found pericytes in Cdh5Cre ERT2 ;Ccm1 fl/fl (Ccm1 ECKO ) mice had a high expression of PDGFRβ. The inhibition of pericyte function by CP-673451 aggravated the CCM lesion development. RNA-sequencing analysis revealed the molecular traits of pericytes, such as highly expressed ECM-related genes, especially Fn1. Furthermore, KLF4 coupled with phosphorylated SMAD3 (pSMAD3) promoted the transcription of fibronectin in the pericytes of CCM lesions. RGDS peptide, an inhibitor of fibronectin, decreased the lesion area in the cerebella and retinas of Ccm1 ECKO mice. Also, human CCM lesions had abundant fibronectin deposition, and pSMAD3- and KLF4-positive pericytes. These findings indicate that pericytes are essential for CCM lesion development, and fibronectin intervention may provide a novel target for therapeutic intervention in such patients.

Effects of polystyrene nanoplastics on oxidative stress, histopathology and intestinal microbiota in largemouth bass (Micropterus salmoides)

Nanoplastics (NPs) can be taken up by aquatic organism and profoundly impact the growth and fitness of aquatic animals in the ecosystem. Currently, the influence of NPs in commercial fish is still poorly documented, especially in carnivorous freshwater fish. To investigate the effects of NPs in water on growth performance, oxidative stress, histopathology, and intestinal microbiota of Micropterus salmoides, juvenile fish (initial weight 14.56 ± 0.09 g) were exposed to 10 and 100 μg/L polystyrene NPs (100 nm) for seven days and nineteen days. The results showed that no significant difference was found in growth among all the experimental groups. NPs caused obvious histological changes in gills (e.g., hyperplasia, curvature, fragmentation, capillary dilatation), livers (e.g., hypertrophy, infiltration, lipid droplet, vacuolization) and intestines (e.g., increase/decrease of gut villus density and length, decrease of goblet cells). The SOD and CAT activities in livers of the high NPs (100 μg/L) group were significantly higher than that of the control group after nineteen-day exposure (P < 0.05). The MDA level of the high NPs (100 μg/L) group was significantly higher than that of the control group after seven-day exposure (P < 0.05), but no significant difference was found in MDA among all the experimental groups after nineteen-day exposure. M. salmoides might adapt to the environment containing NPs through the changes in the intestine microbiota affecting or promoting the growth of the different bacterial genera. This study provides novel insight beyond the current understanding of the potential toxicological effects and NP contamination in M. salmoides.

A case of Coats Disease presenting with Retinal Detachment in Bhutan

Coats disease is a rare retinal disease. It is characterised by abnormal dilatation of retinal capillaries (telangiectasia) and increased vascular permeability (intraretinal and subretinal exudation). In advanced stage of disease the patient can have exudative retinal detachment where the retina detaches from its normal attachment. In some cases there will be secondary increase in intraocular pressure if not treated on time. It has a unilateral presentation in most of the cases. This article describes about a four year old boy who presented with retinal detachment due to coats disease. The patient was managed effectively with external subretinal fluid drainage along with laser and cryotherapy. It is essential to rule out aggressive eye cancer (retinoblastoma) as both can have similar presentation.

Early Retinal Microvasculopathy in Prediabetic Patients and Correlated Factors

Introduction: We aimed to detect early retinal microcirculation changes in prediabetic patients and investigate their correlation with clinical examinations. Methods: Forty-seven prediabetic individuals, 29 controls, and 81 type 2 diabetic mellitus (T2DM) patients were enrolled in this study. A review of clinical data and spectral-domain optical coherence tomography angiography (SD-OCTA) parameters of macular vessel diameter (VD), foveal avascular zone (FAZ), and macular vessel area density (VAD) was performed. Results: Levels of low-density lipoprotein cholesterol and triglycerides in prediabetes and T2DM groups were significantly higher than those in the control group. The urine microalbumin-to-creatinine ratio (ACR) was mildly and moderately increased in the prediabetes and T2DM groups, respectively. The estimated glomerular filtration rate of the three groups was within the normal range. SD-OCTA showed that VAD in the superficial macular area was decreased in the prediabetes group compared to the control group (p = 0.01). The FAZ size, particularly in the deep layer, was expanded in the prediabetes group. In the deep retinal layer of the macular area, VD and FAZ size in the prediabetes group were larger than those in the control group. In the prediabetes group, the axial length was significantly correlated with macular VD and FAZ size (p < 0.05), and ACR was correlated with FAZ size (p < 0.05). Age had a negative correlation with VAD (p < 0.01). ACR had a positive correlation with FAZ size (p < 0.05). Conclusions: Enlargement and irregularity of the FAZ area, deep capillary dilation, and a decrease in VAD occur in the retina of prediabetic patients with mild kidney function impairment.

Electron microscopic investigation of benzo(a)pyrene-induced alterations in the rat kidney tissue and the protective effects of curcumin

ABSTRACT Benzo(a)pyrene (BaP) is a polycyclic hydrocarbon with carcinogenic and DNA damaging properties. Curcumin, primary yellow pigment in turmeric, has a wide range of biological, pharmacological properties in addition to being a powerful antioxidant. The aim of this study was to investigate protective effects of curcumin against benzo(a)pyrene damage in rat kidney. Thirty-six male Wistar albino rats were divided into six groups (n = 6) as: control, corn oil, Dimethyl sulfoxide (DMSO), BaP (10 mg/kg/day), Curcumin (100 mg/kg/day), Curcumin+BaP (100 mg/kg/day+10 mg/kg/day). Agents were daily and orally administered for six weeks. Kidney tissues were removed and examined ultrastructurally. Glomerular and tubular structures in control, corn oil, and DMSO groups demonstrated normal features. Glomerular capillary dilation, thickening, and folding of basement membrane and disruption of organelle contents were distinguished in BaP group. Deletion of podocyte cell and pedicels also sponge-like appearance of glomerular surface were remarkable in this group. Tissue components were protected in curcumin treated group. Proximal tubules and glomerular basement membrane exhibited normal features in Curcumin+BaP group. The abnormalities that accompanied BaP administration clearly revealed the detrimental effects of this agent. Therefore, this study provided substantial evidence that curcumin protects against benzo(a)pyrene nephrotoxicity.

Peripheral Microvascular Abnormalities Associated with Open-Angle Glaucoma

To investigate peripheral microvascular abnormalities associated with patients with open-angle glaucoma (OAG). This was a cross-sectional study. Patients with OAG and controls. All subjects underwent detailed ophthalmic evaluation, including Humphrey visual field (HVF) tests and swept source OCT. To evaluate peripheral microvascular abnormalities, nailfold capillaroscopy (NFC) and laser Doppler imaging (LDI) were performed. The presence of microhemorrhages, tortuous capillaries, dilated capillaries, avascular areas, and the capillary density, among other characteristics, were recorded using NFC; fingertip blood flow (FBF) was measured using LDI at different time points, before and 1, 10, and 20 minutes after exposure to a cold stimulus. In addition, venous blood samples were collected to measure serum endothelin-1 (ET-1) concentrations as well as serum autoantibodies. Presence of microhemorrhages, tortuous capillaries, and dilated capillaries; FBF; ET-1; and autoantibodies. Sixty-eight subjects (43 patients with OAG and 25 controls) were enrolled in the study. Microhemorrhages were found in the nail bed of 65.1% of the patients with OAG compared with 25.0% of the controls (P= 0.003). There was a significant difference in the mean FBF at the baseline in patients with OAG versus controls (293.6 ± 100.2 vs 388.8 ± 52.0 perfusion units, respectively, P < 0.001), together with a significant decrease in the mean FBF 10 and 20 minutes after cold stimulus in patients with OAG in comparison to controls (P < 0.001 for all comparisons). There was a positive correlation between mean baseline FBF and HVF mean deviation (r= 0.27, P= 0.03) and between mean baseline FBF and average retinal nerve fiber layer thickness (r=0.44, P= 0.001). Neither the analysis of ET-1 concentrations (P= 0.71) nor the autoantibodies measurements (P > 0.05, for all) showed any difference between the 2 groups. Significant peripheral microvascular abnormalities were found in patients with OAG compared to controls, suggesting that microvascular changes might play a role in the pathogenesis of the disease. In addition, part of these peripheral microvascular abnormalities seems to be correlated with both functional and structural glaucomatous damage. The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Red blood cell dynamics in extravascular biological tissues modelled as canonical disordered porous media.

The dynamics of blood flow in the smallest vessels and passages of the human body, where the cellular character of blood becomes prominent, plays a dominant role in the transport and exchange of solutes. Recent studies have revealed that the microhaemodynamics of a vascular network is underpinned by its interconnected structure, and certain structural alterations such as capillary dilation and blockage can substantially change blood flow patterns. However, for extravascular media with disordered microstructure (e.g. the porous intervillous space in the placenta), it remains unclear how the medium's structure affects the haemodynamics. Here, we simulate cellular blood flow in simple models of canonical porous media representative of extravascular biological tissue, with corroborative microfluidic experiments performed for validation purposes. For the media considered here, we observe three main effects: first, the relative apparent viscosity of blood increases with the structural disorder of the medium; second, the presence of red blood cells (RBCs) dynamically alters the flow distribution in the medium; third, symmetry breaking introduced by moderate structural disorder can promote more homogeneous distribution of RBCs. Our findings contribute to a better understanding of the cell-scale haemodynamics that mediates the relationship linking the function of certain biological tissues to their microstructure.

Pericyte remodeling is deficient in the aged brain and contributes to impaired capillary flow and structure

Deterioration of brain capillary flow and architecture is a hallmark of aging and dementia. It remains unclear how loss of brain pericytes in these conditions contributes to capillary dysfunction. Here, we conduct cause-and-effect studies by optically ablating pericytes in adult and aged mice in vivo. Focal pericyte loss induces capillary dilation without blood-brain barrier disruption. These abnormal dilations are exacerbated in the aged brain, and result in increased flow heterogeneity in capillary networks. A subset of affected capillaries experience reduced perfusion due to flow steal. Some capillaries stall in flow and regress, leading to loss of capillary connectivity. Remodeling of neighboring pericytes restores endothelial coverage and vascular tone within days. Pericyte remodeling is slower in the aged brain, resulting in regions of persistent capillary dilation. These findings link pericyte loss to disruption of capillary flow and structure. They also identify pericyte remodeling as a therapeutic target to preserve capillary flow dynamics.

Laser Treatment Modalities for Diabetic Retinopathy

Diabetes is a chronic progressive metabolic disorder that is caused by the body's inability to regulate blood glucose levels. If uncontrolled, it can lead to various complications. Among its various complications, long-term diabetes leads to diabetic retinopathy (DR). It is a disease involving blood vessels and the destruction of retinal nerves. It is usually classified into two types: proliferativediabetic retinopathy (PDR) and nonproliferative diabetic retinopathy (NPDR). It progresses and causes loss of vision. The leading cause of loss of vision is diabetic macular edema (DME). The argon laser is used as a modality in the management of PDR. There are various types of laser photocoagulation, such as peripheral retinal laser photocoagulation,focal macular laser photocoagulation, and grid photocoagulation. DR results in various adverse consequences such as vitreous hemorrhage, fibrosis, traction, detachment of the retina, and glaucoma. To assess DR, a detailedfundus examination with a slit lamp biomicroscopeneeds to be done. Seven-standard field stereoscopic-color fundus photography needs to be done for documentation and follow-up. Patients with diabetesmellitus (DM) type 1 have a greater risk of suffering fromDR. Another major complication of the condition is DME, which is characterized by an increase in the permeability of vessels and the thickening of the central part of the retina along with the accumulation of hard exudates on the macula. This article discussesvarious laser therapy modalities for the treatment of DR, their types, mechanisms, and aims. Clinical features of DR include abnormal dilatation of capillaries, and outpouchings in the form of microaneurysm from the capillary wallareone of the earliest and most dangerous changes; later, non-perfusion of the retina occurs, which is associated with cotton wool spots and blot hemorrhages. In patients suffering from PDR and maculopathy, peripheral retinal laser photocoagulation is used as a mode of intervention.

Sodium chloride against Dawestrema cycloancistrium in juvenile Arapaima gigas

The aim of the present study was to assess the use of sodium chloride (NaCl) against monogenoid trematodes infestations in pirarucu (Arapaima gigas). Two assays were conducted with pirarucu juveniles, the first comprising an in vitro exposure to 8, 9, 10, and 11 g·L−1 NaCl and the second, in vivo exposure test to NaCl at the same concentrations. The best in vitro results were observed for 1-h exposures at 9, 10, and 11 g·L−1 NaCl, resulting in 60% and 100% parasite mortality, respectively. In vivo exposures to 8 and 10 g·L−1 NaCl were 36 and 22% efficient, respectively, following 2 h of exposure, with no mortality. Some dose-dependent changes were observed in exposed fish, such as decreased hemoglobin and MCHC values at the highest NaCl concentration compared to the other NaCl concentrations and the control group. Most frequent gill tissue alterations observed were capillary dilatation and mucus secretions compared to the control group at the highest NaCl concentrations (10 and 11 g·L−1). Decreased mean (p < 0.05) water pH values and increased mean electrical conductivity were noted compared to the control group. In conclusion, our findings suggest that NaCl exhibits low toxicity toward pirarucu without physiological alterations and anthelmintic activity to the monogenoid directly influenced by exposure time and concentration. Moreover, 100% of the monogenoids present in the gills of the fish were identified as Dawestrema cycloancistrium.

Nerve changes associated with post thoracotomy pain syndrome.

Chronic post-thoracotomy pain (PTPS) is a frequent complication of thoracic operations. Sometimes the pain is excruciating enough to impair activities of daily living (ADL). All thoracic procedures have the potential to cause trauma to the intercostal nerves due to retractor use, chest closure techniques, and or wound healing. In our study, we analyzed the microscopic aspects of the nerves involved in the healing process, to better understand the histopathology of chronic pain. 29 patients with PTPS underwent intercostal neurectomy to alleviate the symptoms. Microscopic specimens harvested during the surgeries were sent to our pathology unit for evaluation. The following data regarding the surgical procedures was collected: surgical approach, chest closure type, number of excised nerves, and time interval from previous surgery to neurectomy. A mean of 2.34±1.11 nerves were excised. Microscopy of the specimens revealed: fibrosis, hyalinization of the epineurium and perineurium, intense hyperemia of the blood capillaries, and interstitial edema. 7 cases presented with myxoid degeneration of epineurium and perineurium. In all the cases, endoneurium, myelin sheaths, and axons were interrupted. The endoneurium showed the presence of hyperemic dilated capillaries. The segmental cytoplasmic vacuolization of Schwann's cells with the total disappearance of axons was also noted. 60% of the examined specimens had intraneural myxoid degeneration, with highly dense irregular connective tissue around nerve fibers. The pathologic findings in the structure of the intercostal nerves obtained from the patients are indicative of the involvement of the wound healing mechanisms in PTPS. The negative impact of wound healing could be considered a key component in the development of intense chronic pain.

S2598 Gastric Kaposi Sarcoma Presenting as Acute Upper Gastrointestinal Hemorrhage in a Heart Transplant Patient

Introduction: Kaposi sarcoma (KS), a multifocal neoplasm of lymphatic cells, occurs more often in organ transplant patients, and its pathogenesis is related to use of immunosuppressive (IS) medications. Acute gastrointestinal hemorrhage due to KS is exceedingly rare and has never been reported in a heart transplant patient. We report a case of KS presenting as gastrointestinal hemorrhage in a heart transplant patient whose bleeding resolved with supportive care and treatment of his underlying KS. Case Description/Methods: A 63-year-old man originally from Sudan with a history of non-ischemic cardiomyopathy requiring heart transplant on IS presented with melena and acute anemia. Medical history included cutaneous KS of the right leg diagnosed 1 year following transplant previously treated with paclitaxel and in clinical remission. He was treated with intravenous proton-pump inhibitor and blood transfusions. EGD showed a patch of nodular mucosa on the lesser curvature of the stomach. Pathology of the nodule showed dilated capillaries with spindle cells in the lamina propria, and staining for human herpesvirus-8 (HHV-8) was positive in the spindled cells, supporting a diagnosis of recurrent KS. He had no further bleeding, hemoglobin stabilized, and he was discharged. He was resumed on paclitaxel for recurrent KS after discharge and had no further bleeding (Figure 1). Discussion: We report a case of KS presenting with GI bleeding in a patient on chronic IS following heart transplant. While GI bleeding from KS has been reported in renal transplant recipients, this is the first such report we are aware of in a heart transplant patient. The GI tract is a common site of visceral involvement in KS, and presentation can include vomiting, diarrhea, and occult blood loss. Overt GI bleeding in KS is rare. Endoscopic appearance varies from flat lesions to polypoid or nodular growths, and histopathology shows spindle cells positive for HHV-8. Management of GI bleeding in KS depends on severity, and in less severe cases, the role of endoscopy is to confirm the visceral spread of KS with biopsy. Thereafter, management includes IS reduction and chemotherapy for refractory disease. Though KS is a rare cause of overt GI bleeding, it should be considered in patients with immunodeficiency or on chronic IS, and biopsy for suspicious lesions should be performed to confirm diagnosis.Figure 1.: Lesser curvature gastric nodule.