Malignant glomus tumor with oncocytic features: an unusual presentation of dysphagia.

Glomus tumors in the gastrointestinal tract are unusual, as the previous series in the literature have been mainly limited to the stomach. Less than 10 cases of esophageal glomus tumors have been described in the literature. Oncocytic glomus tumors are a recently identified, rare variant of the glomus tumor. We report a 47-year-old female who presented with an approximately 3-month history of dysphagia and weight loss. Upper gastrointestinal endoscopy showed a black-purple, hypervascular, protruding lesion measuring approximately 65 mm at the 37th cm of the esophagus. The patient underwent an Ivor Lewis operation via open thoracotomy. The resected specimen had a protuberant, ulcerated mass measuring 80 × 35 mm in the posterior wall of the esophagus. Based on the histopathological, immunohistochemical and electron microscope findings, the final diagnosis was a malignant glomus tumor with oncocytic features. To our knowledge, this is the first report of a malignant glomus tumor with oncocytic features in an esophageal location.

The chondroprotective effects of intraarticular application of statin in osteoarthritis: An experimental study.

BACKGROUND: Osteoarthritis (OA) is the most frequent chronic joint disease causing pain and disability. Recent reports have shown that statin may have the potential to inhibit osteoarthritis. This study of early stage OA developed in an experimental rabbit model, aimed to evaluate the chondroprotective effects of intraarticularly applied atorvastatin on cartilage tissue macroscopically and histopathologically by examining intracellular and extracellular changes by light and electron microscope. MATERIALS AND METHODS: The experimental knee OA model was created by cutting the anterior cruciate ligament of the 20 mature New Zealand rabbits. The rabbits were randomly allocated into two groups of 10. STUDY GROUP: The group that received intraarticular statin therapy; CONTROL GROUP: The group that did not receive any intraarticular statin therapy. The control group received an intraarticular administration of saline and the study group atorvastatin from the 1(st) week postoperatively, once a week for 3 weeks. The knee joints were removed including the femoral and tibial joint surfaces for light and electron microscopic studies of articular cartilages. RESULTS: The mean total points obtained from the evaluation of the lesions that developed in the medial femoral condyle were 11.33 ± 0.667 for the control group and 1.5 ± 0.687 for the study group. The mean total points obtained from the evaluation of the lesions that developed in medial tibial plateau cartilage tissue were 11.56 ± 0.709 for the control group and 1.40 ± 0.618 for the study group. Electron microscopic evaluation revealed healthy cartilage tissue with appropriate chondrocyte and matrix structure in study group and impaired cartilage tissue in control group. CONCLUSION: Chondroprotective effect of statin on cartilage tissue was determined in this experimental OA model evaluated macroscopically and by light and electron microscope. There are some evidences to believe that the chondroprotective effect of the statin is that, by protecting the structure of the endoplasmic reticulum and the Golgi complex.

Histological evaluation of wound healing performance of electrospun poly(vinyl alcohol)/sodium alginate as wound dressing in vivo.

Poly(vinyl alcohol)/sodium alginate nanofibrous mats were produced by electrospinning method at optimum process parameters. Evaluation of alginate-based electrospun nanofibrous mats as a wound dressing material and their comparison to commercially available wound dressings produced with conventional methods were carried out in vivo. Tissue specimens were examined histopathologically on 4th, 6th, 15th, 21st postoperative days. In contrast to other dressings it was observed that nanofibrous mat could survive on the wound crust in early stages of healing. In terms of epithelization, epidermis characteristics, vascularization and formation of hair follicles, nanofibrous mat showed the best healing performance. This could be explained with presence of nanofibrous mat acting as an artificial skin on the wound region until new tissue regenerated.

Effects of temporary vascular occluder poloxamer 407 gel on the endothelium.

BACKGROUND: Coronary occlusion techniques during OPCAB may lead to an endothelial damage to the target vessel. The adverse effects of these techniques are well-known, and researches have been trying to find out new materials to occlude the coronary artery without an endothelial damage. In the present study, we investigate to the endothelial damage in the rat aorta which is occluded by Poloxamer 407 gel. METHODS: Forty-five rats were randomized in three groups: (1) segment of the aorta was occluded with Poloxamer 407 gel in P 407 group; (2) segment of the aorta was occluded with microvascular clamp in MV clamp group; and (3) no onclusion was available in the Control group. The rats were sacrificed of observation, and a 15mm segment of the aorta was obtained as a specimen. Integrity of the endothelial lining was observed with a scanning electron microscopy. RESULTS: Scanning electron microscopy revealed a statistically significant difference among the 3 groups (p<0,001) using the SPSS 13.0 test. No difference was found between the Control group and the P 407 group (p=0,059). The differences between MV clamp-Control group (p<0,001) and MV clamp-P 407 group were statistically significant (p<0,002). CONCLUSIONS: We suggest that Poloxamer 407 gel occlusion may be a safer and more effective method compared to the microvascular clamp occlusion.

The effect of catheter use on vein grafting of a peripheral nerve defect: an experimental study.

BACKGROUND: Since vein grafts have been used in the repair of nerve defects, studies regarding this procedure have accumulated, and after coming into clinical use, it was noticed that there is a problem of collapse in the vein graft. METHODS: Forty Sprague-Dawley rats were used, divided into five groups. No surgical intervention was performed in the first group. The defect was created in the sciatic nerve in Group 2 and left unrepaired. In Group 3, the defect was repaired with a nerve graft. In Group 4, the defect was repaired with a vein graft, while in Group 5, the repair was performed using a vein graft with an inserted catheter. In order to evaluate functional recovery and nerve regeneration, walking track analysis, electrophysiologic and histomorphometric analyses were done at the end of the 12th week. RESULTS: Although there were no functional differences between Groups 5 and 4, comparisons regarding nerve conduction velocity demonstrated that the results obtained in Group 5 were better than those in Group 4. When the number of axons on the distal part of the sciatic nerve and mid-segment of the repaired area was taken into account, no significant difference was found between Groups 3 and 5, whereas there was a significant difference between Groups 4 and 5. CONCLUSION: In our study, it was experimentally shown that the problem of collapse of a vein graft occurring after its use in the reconstruction of a nerve defect can be overcome by placing a catheter into the vein graft. Consequently, this method may eliminate the need for the use of a nerve graft in selected cases.

Activation of orexin neurons through non-NMDA glutamate receptors evidenced by c-Fos immunohistochemistry.

Orexin neuropeptides participate in the regulation of feeding as well as the regulation and maintenance of wakefulness and the cognitive functions. Orexin A and B share a common precursor, prepro-orexin and neurons are localized in the lateral hypothalamus. Physiological studies showed that these neurons are regulated by glutamatergic innervations. We aimed to assess the effects of kainic acid as a potent agonist for non-NMDA glutamate receptors in the activation of orexin neurons. We also analyzed the effect of glutamate antagonist CNQX, injected prior to kainic acid, on this activation. Expression of c-Fos protein was used as a marker for neuronal activation. Dual immunohistochemical labeling was performed for prepro-orexin and c-Fos and the percentages of c-Fos-expressing orexin neurons were obtained for control, kainic acid, and CNQX groups. Kainic acid injection caused statistically significant increase in the number of c-Fos-positive neurons when compared to control group (62.69 and 36.31%, respectively). Activation of orexin neurons was blocked, in part, by CNQX (43.36%). In the light of these results, it is concluded that glutamate takes part in the regulation of orexin neurons and partially exerts its effects through non-NMDA glutamate receptors and that orexin neurons express functional non-NMDA receptors.

Kainic acid activates oxytocinergic neurons through non-nmda glutamate receptors.

The present study assessed if kainic acid activates oxytocinergic neurons and this activation is blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). Dual immunohistochemistry for oxytocin and c-Fos showed that oxytocin neurons in SON and PVN express c-Fos following kainic acid administration, a significant increase when compared to the control group. Administration of CNQX prior to kainic acid caused a significant reduction. The results suggested the participation of non-NMDA receptors in the regulation of oxytocin neurons because the administration of kainic acid activates these neurons and this activation is blocked by CNQX administration.

The effect of vitamin A on CCl4-induced hepatic injuries in rats: a histochemical, immunohistochemical and ultrastructural study.

In this study, we aimed to investigate the effect of vitamin A on the transformation of the Ito cells to fibrogenic form and suppression of the development of fibrosis. Carbon tetrachloride intoxication was performed on rats for 2, 8, 12 or 20 weeks and 5x10(4) IU vitamin A (as retinol palmitate) was injected subcutaneously once every 4 weeks. Ito cells were detected by gold chloride impregnation, as well as desmin and alpha-smooth muscle actin (alpha-SMA) immunohistochemistry. Additionally, all groups were examined ultrastructurally. The number of Ito cells that were labelled positively with gold impregnation decreased in the fibrotic groups; however, alpha-SMA and desmin immunopositive Ito cells increased. The samples from animals that were treated with vitamin A showed an increase in labelling with gold impregnation but a decrease in alpha-SMA immunopositivity. The data showed that vitamin A can prevent hepatic injury, by suppressing the transformation of Ito cells to fibrogenic form. We conclude that vitamin A has potential for the treatment of hepatic fibrotic diseases. Alpha-SMA immunohistochemistry was found to be more informative than desmin immunohistochemistry for monitoring liver fibrosis.

Localization of kainate receptor subunit GluR5-immunoreactive cells in the rat hypothalamus.

Glutamate is the major excitatory neurotransmitter in the hypothalamus, which exerts its effects by activating ion channel-forming (ionotropic) or G-protein-coupled (metabotropic) receptors. Kainate-preferring glutamate receptor subunits (GluR5, GluR6, GluR7, KA1, and KA2) form one of the three ionotropic receptor families. In the present study, we analyzed the distribution of GluR5 subunit protein in the rat hypothalamus with immunohistochemistry. GluR5 immunoreactivity was observed in perikarya and processes of many hypothalamic cells some of which, based upon their morphological differentiation by size and structure, appeared to be neurons and others glial cells. Analyses revealed that higher number of glial cells were GluR5 positive when compared to the moderate number of GluR5-labeled neurons in the anteroventral periventricular nucleus. Numerous GluR5-expressing neurons and similar number of glia were detected in the suprachiasmatic nucleus. In the arcuate nucleus more glial cells were identified with GluR5 immunoreactivity than the number of labeled neurons. Scattered GluR5-positive cells were present in the periventricular nucleus. Specific immunostaining was not seen in the ventromedial nucleus or dorsomedial nucleus. In conclusion, it is suggested that the GluR5 subunits participate in the glutamatergic regulation of several neuroendocrine systems, such as the tubero-infundibular systems as well as in the control of circadian output through neuron-to-neuron and/or neuron-to-glia interactions.

A new surgical approach for indocyanine green-assisted internal limiting membrane peeling.

BACKGROUND AND OBJECTIVE: The efficiency of indocyanine green (ICG) dye in the removal of the internal limiting membrane (ILM) with a fluid needle using passive aspiration was evaluated. PATIENTS AND METHODS: Eighteen consecutive patients with diffuse diabetic macular edema were studied. After vitrectomy and total fluid-air exchange, 0.1 mL of ICG solution 0.25% was left in the macular area for 1 minute. Then the macular ILM was peeled with a specially designed tapered fluid needle using passive aspiration. RESULTS: In 16 of the 18 eyes, the peeling procedure could be easily performed with a tapered fluid needle using passive aspiration. In 11 eyes, partial development of spontaneous ILM detachment prior to the peeling process was also observed. CONCLUSIONS: ICG solution 0.25% appears to reduce the adhesive force of the ILM to the sensory retina, which makes the removal of the ILM much easier by passive aspiration with a fluid needle.

Syndecan-1 (CD138) expression in acute myeloblastic leukemia cells--an immuno electron microscopic study.

Syndecan-1 (CD138), an important transmembrane heparan sulfate proteoglycan is expressed in distinct stages of cell differentiation. Although its expression in acute lymphoblastic leukemia (ALL) cells is well known: its function or presence in acute myeloblastic leukemia (AML) cells is still largely unknown. The expression of syndecan-1 was studied in bone marrow biopsies of three patients with AML using electron microscopic immunocytochemistry. Positive expression of syndecan-1 was found in AML cells. These results suggest that syndecan-1 expression is not only a characteristic phenotypic marker for ALL, but is also expressed in AML cells.