The effects of di(2-ethylhexyl)phthalate on rat liver in relation to selenium status.

This study was performed to determine the hepatotoxicity of di(2-ethylhexyl)phthalate (DEHP) in relation to selenium status. In 3-week-old Sprague-Dawley rats, selenium deficiency was induced by a ≤0.05 selenium mg/kg. A selenium supplementation group was given 1 mg selenium/kg diet for 5 weeks. Di(2-ethylhexyl)phthalate-treated groups received 1000 mg/kg dose by gavage during the last 10 days of the experiment. Histopathology, peroxisome proliferation, catalase (CAT) immunoreactivity and activity and apoptosis were assessed. Activities of antioxidant selenoenzymes [glutathione peroxidase 1 (GPx1), glutathione peroxidase 4 (GPx4), thioredoxin reductase (TrxR1)], superoxide dismutase (SOD), and glutathione S-transferase (GST); aminotransferase, total glutathione (tGSH), and lipid peroxidation (LP) levels were measured. Di(2-ethylhexyl)phthalate caused cellular disorganization while necrosis and inflammatory cell infiltration were observed in Se-deficient DEHP group (DEHP/SeD). Catalase activity and immunoreactivity were increased in all DEHP-treated groups. Glutathione peroxidase 1 and GPx4 activities decreased significantly in DEHP and DEHP/SeD groups, while GST activities decreased in all DEHP-exposed groups. Thioredoxin reductase activity increased in DEHP and DEHP/SeS, while total SOD activities increased in all DEHP-treated groups. Lipid peroxidation levels increased significantly in SeD (26%), DEHP (38%) and DEHP/SeD (71%) groups. Selenium supplementation partially ameliorated DEHP-induced hepatotoxicity; while in DEHP/SeD group, drastic changes in hepatic histopathology and oxidative stress parameters were observed.

The effects of di(2-ethylhexyl)phthalate exposure and selenium nutrition on sertoli cell vimentin structure and germ-cell apoptosis in rat testis.

This study aimed to investigate the effects of di(2-ethylhexyl)phthalate (DEHP) on Sertoli-cell vimentin filaments and germ-cell apoptosis in testes of pubertal rats at different selenium (Se) status. Se deficiency was produced in 3-weeks old Sprague-Dawley rats by feeding them ≤ 0.05 Se mg/kg diet for 5 weeks, Se supplementation group was on 1 mg Se/kg diet, and DEHP was applied at 1000 mg/kg dose by gavage during the last 10 days of the feeding period. The diet with excess Se did not cause any appreciable alteration in vimentin staining and apoptosis of germ cells, but Se deficiency caused a mild decrease in the intensity of vimentin immunoreactivity and enhanced germ-cell apoptosis significantly (approximately 3-fold, p <0.0033). DEHP exposure caused disruption and collapse of vimentin filaments and significantly induced apoptotic death of germ cells (approximately 8-fold, p <0.0033). In DEHP-exposed Se-deficient animals, compared with the control, collapse of vimentin filaments was more prominent; there was serious damage to the seminiferous epithelium; and a high increment (approximately 25-fold, p <0.0033) in apoptotic germ cells was observed. Thus, Se deficiency exacerbated the toxicity of DEHP on Sertoli cells and spermatogenesis, whereas Se supplementation provided protection. These results put forward the critical role of Se in the modulation of redox status of testicular cells and emphasize the importance of Se status for reproductive health.

Reproductive toxicity of di(2-ethylhexyl) phthalate in selenium-supplemented and selenium-deficient rats.

Phthalates are abundantly produced plasticizers, and di(ethylhexyl) phthalate (DEHP) is the most widely used derivative in various consumer products and medical devices. Animal studies show that DEHP and various other phthalates cause reproductive and developmental toxicity. Although the evidences are limited, it seems reasonable that DEHP may have a potential for similar adverse effects in humans. Such concerns are increasing, particularly for the developing reproductive system of male infants and children. By taking into account the essentiality of selenium (Se) in testicular structure and functions and the high prevalence of inadequate Se intake in various part of the world, this study was designed to investigate the testicular toxicity of DEHP in Se-deficient male rats and to examine the possible preventive effects of Se supplementation on phthalate toxicity. Se deficiency was generated by feeding 3-week-old Sprague-Dawley rats with a ≤0.05 Se mg/kg diet for 5 weeks. Supplementation groups were on a 1 mg Se/kg diet, and DEHP-treated groups received a 1,000 mg/kg dose by gavage during the last 10 days of the feeding period. Testicular histopathology, sperm count and motility, and sperm morphology were examined, and plasma levels of sex hormones were measured. Toxicity and antiandrogenic effects of DEHP were evidenced by disturbed testicular histology and spermatogenesis, diminished testosterone, leutinizing hormone (LH) and follicle stimulating hormone (FSH) levels, and sperm motility. The effects of DEHP were much more pronounced in Se-deficient rats, whereas Se supplementation was found to be protective, reflecting its regulating role in cellular redox equilibrium.

Disruption of PTPRO causes childhood-onset nephrotic syndrome.

Idiopathic nephrotic syndrome (INS) is a genetically heterogeneous group of disorders characterized by proteinuria, hypoalbuminemia, and edema. Because it typically results in end-stage kidney disease, the steroid-resistant subtype (SRNS) of INS is especially important when it occurs in children. The present study included 29 affected and 22 normal individuals from 17 SRNS families; genome-wide analysis was performed with Affymetrix 250K SNP arrays followed by homozygosity mapping. A large homozygous stretch on chromosomal region 12p12 was identified in one consanguineous family with two affected siblings. Direct sequencing of protein tyrosine phosphatase receptor type O (PTPRO; also known as glomerular epithelial protein-1 [GLEPP1]) showed homozygous c.2627+1G>T donor splice-site mutation. This mutation causes skipping of the evolutionarily conserved exon 16 (p.Glu854_Trp876del) at the RNA level. Immunohistochemistry with GLEPP1 antibody showed a similar staining pattern in the podocytes of the diseased and control kidney tissues. We used a highly polymorphic intragenic DNA marker-D12S1303-to search for homozygosity in 120 Turkish and 13 non-Turkish individuals in the PodoNet registry. This analysis yielded 17 candidate families, and a distinct homozygous c.2745+1G>A donor splice-site mutation in PTPRO was further identified via DNA sequencing in a second Turkish family. This mutation causes skipping of exon 19, and this introduces a premature stop codon at the very beginning of exon 20 (p.Asn888Lysfs*3) and causes degradation of mRNA via nonsense-mediated decay. Immunohistochemical analysis showed complete absence of immunoreactive PTPRO. Ultrastructural alterations, such as diffuse foot process fusion and extensive microvillus transformation of podocytes, were observed via electron microscopy in both families. The present study introduces mutations in PTPRO as another cause of autosomal-recessive nephrotic syndrome.

Rosuvastatin induces apoptosis in cultured human papillary thyroid cancer cells.

Statins show antiproliferative activity in various cancer cells. The aim of this study was to evaluate the effects of rosuvastatin treatment on papillary thyroid carcinoma. The papillary thyroid carcinoma (B-CPAP) and normal (Nthy-ori 3-1) thyroid cell lines were treated with rosuvastatin at 12.5, 18.5, 25, 50, 100, and 200 µM concentrations. After 48 and 72 h of rosuvastatin treatment, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, Ki-67 immunolabeling, FACS analysis, electron microscopy, caspase-3, and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) analysis were performed. Decreased cell viability and G1 phase arrest were detected in papillary thyroid cell line treated with rosuvastatin. Positive immunoreactivity of Ki-67 and dose-dependent increase in S phase on Nthy-ori 3-1 cells were also detected. B-CPAP cells showed intense vacuolisation and autophagosomes with low concentrations and 48 h incubations, while Nthy-ori 3-1 cells showed these changes at higher concentrations. A decrease in the percentage of cells showing autophagy was determined with increasing concentrations of rosuvastatin in B-CPAP cells. Rosuvastatin treatment also caused a dose- and time-dependent increase in caspase-3 activity and apoptotic index by TUNEL assay in B-CPAP cells compared with the Nthy-ori 3-1 cells. Apoptotic cells with nuclear condensation and fragmentation were observed in B-CPAP cell line. Rosuvastatin induced autophagic changes in B-CPAP papillary thyroid cancer cells in lower doses and caused a shift from autophagy to apoptosis. Rosuvastatin may be an alternative treatment for refractory papillary thyroid cancer. Further in vivo studies are necessary to clarify the effects of rosuvastatin in papillary thyroid carcinoma and the clinical implications of rosuvastatin treatment.

Fluid resuscitation of acute hemorrhage in uninephrectomized rabbits--effects on the early function of the remnant kidney.

The aim of this study was to determine the effects of fluid resuscitation of acute hemorrhage on the early function and histopathology of the remnant kidney in uninephrectomized rabbits. Thirty-nine adult rabbits were studied in four groups. Group 1 (n = 8) included healthy controls; Group 2 (n = 10) healthy, bled animals; Group 3 (n = 10) uninephrectomized, non-bled animals; and Group 4 (n = 11) uninephrectomized, bled animals. In the hemorrhage groups, 8 mL kg(-1) of blood was drawn, and replaced with lactated Ringer's solution three times the volume of shed blood. Urine and blood samples were collected after 120-minutes of observation. None of the animals experienced hypotension during the study period. Serum and urinary electrolytes were similar between the Groups (p > 0.05). Urine output was lower in Groups 3 and 4 than in Group 1 (p = 0.001, both). Urinary microalbumin, NAG, fractional sodium excretion and creatinine clearance were similar in all four Groups. Light microscopic evaluation revealed only slight enlargement of the proximal tubule lumen in the renal medulla of the rabbits that were both uninephrectomized and bled. We observed no deleterious effects of well resuscitated hemorrhage on early function and histopathology of the remnant kidney in uninephrectomized rabbits.

Effect of intraarticular injection of lornoxicam on the articular cartilage & synovium in rat.

BACKGROUND & OBJECTIVE: Intraarticular (i.a) drug application is consider to be a new therapeutic approach for the treatment of postoperative pain after arthroscopic knee surgery without any systemic adverse effects. Lornoxicam, a nonsteroid anti-inflammatory drug is a short acting agent, and its anti-inflammatory and analgesic activity may be effective in the postoperative pain management in minor surgery. In this study, the effects of intraarticular administration of lornoxicam on the synovium and articular cartilage in the rat knee joint were investigated. METHODS: Lornoxicam (0.25 ml) was given as an injection into the right knee joint and 0.25 ml of 0.9 per cent saline solution by injection into the left knee joint as a control in 25 rats. Groups of five rats were sacrificed by a lethal injection of ketamine 1st, 2nd, 7th, 14th and 21st days after lornoxicam administration. Knee joints were detached, fixed in 10 per cent buffered formalin and decalcified. Serial sections of 5 microm were stained with haematoxylin-eosin and evaluated for the presence of inflammation in the articular, periarticular regions and synovium. Inflammatory changes in the joints were graded according to a five-point scale, histologically. RESULTS: There were no significant differences in inflammation and cartilage degeneration, between control and lornoxicam applied knees. Grade 3 inflammatory changes occurred only in one knee in lornoxicam group, at 24 h after injection. No pathological changes were observed in both groups at any time point. INTERPRETATION & CONCLUSION: Lornoxicam did not show significant effect on inflammation on rat synovia in knee joint. Further studies including in human need to be done before any recommendations are made for i.a. administration of lornoxicam.

Immunohistochemical analysis of small plaque parapsoriasis: involvement of dendritic cells.

Small plaque parapsoriasis (SPP) is one of the cutaneous T-cell lymphoproliferative disorders. The aim of the present study was to show the antigenic profile of a subset of dendritic cells and lymphocytes in SPP in comparison with normal cells to provide data on the role of these two cell types in the pathogenesis of SPP. Skin biopsy specimens of lesions were obtained from 8 patients with SPP. Biopsies of the healthy skin from 9 control individuals were also analyzed. Immunohistochemistry was performed on the frozen tissue sections to reveal binding of anti-HLA Class II, anti-CD1a, anti-CD4, anti-CD8, anti-CD44, anti-CD45, and anti-CD68 monoclonal antibodies. There was a statistically significant increase in the number of CD1a(+), Langerhans cells (LCs), HLA-DR-immunoreactive and, CD1a-positive dermal dendritic cells and CD68(+) macrophages in the SPP group (p=0.008, 0.008, 0.002 and <0.0009, respectively). The number of lymphocytes positive for CD4, CD8 and CD45 was significantly higher than normal in the SPP group (p=0.015, <0.0009 and <0.0009, respectively). Our study demonstrates that both peptide- and lipid-based antigens are involved in the persistent antigenic exposure in SPP. Dendritic cells play a pivotal role in SPP by presenting antigens by both LC and dermal dendritic cells via MHC Class II and CD1a molecules. The CD68(+) macrophages are thought to be involved in the immune response in this pathology as an antigen-presenting cell.

The neocartilaginous formation with hydroxyl-apatite in injection laryngoplasty: an experimental study on rabbit model.

Adductor paralysis or the pathologies occurring after laryngeal surgery such as scarring or atrophy of the vocal cords cause glottic insufficiency during phonation. Injection laryngoplasty has been a widely accepted technique due to lower morbidity of the procedure and the applicability via endoscope in the treatment of these pathologies. Various materials have been used in injection laryngoplasty. The primary expectations in these techniques are the persistence of injected material long enough, without resorbtion or any cause of serious tissue response and having beneficial effects in reinforcing the glottic tissue. In the present study, we used large molecular-sized calcium hydroxyl-apatite (CaHA) particles in injection laryngoplasty to observe the effects of the material in the laryngeal tissues under the light microscopic examination. The study was performed on 12 rabbits in four groups. After injecting Ca10 (PO4)6(OH)2 (Coaptite) into their vocal folds, the rabbits were killed at certain intervals, in the 1st week (group 1) in the 1st month (group 2) in the 3rd month (group 3) and in the 6th month (group 4). Larynges were removed and processed for light microscopic observations. Our observations revealed that this material induced the new cartilage formation without a serious tissue response in the larynges. Formation of a new cartilage tissue was the most significant, but an unexpected outcome of the study. The injected material inducing a neocartilage formation without any tissue reaction persisted long enough in the laryngeal tissues. Although neocartilage formation may interfere the vocal fold vibrations, providing glottic closure in the phonation with a durable material will be an important gain.

Cod liver oil supplementation improves cardiovascular and metabolic abnormalities in streptozotocin diabetic rats.

Abnormalities in the metabolism of essential fatty acids and the results of increased oxidative stress have been implicated in cardiovascular disorders observed in diabetes mellitus. This study, therefore, aimed to investigate the effects of cod liver oil (CLO, Lysi Ltd, Iceland), which comprises mainly an antioxidant vitamin A, n:3 polyunsaturated fatty acids (n:3 PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on cardiovascular abnormalities in streptozotocin (STZ)-diabetic rats. Two days after single STZ (55 mg kg(-1), i.p.) or vehicle injection, diabetes was verified by increased blood glucose, and non-diabetic and diabetic rats were left untreated or treated with CLO (0.5 mL kg(-1) daily, by intragastric probing) for 12 weeks. Plasma glucose, triacylglycerol and cholesterol concentrations were significantly elevated in 12-week untreated-diabetic rats; CLO provided better weight gain, entirely prevented the plasma lipid abnormalities, but partially controlled the glycaemia in diabetic rats. In isolated aorta rings, diabetes resulted in increased phenylephrine-induced vasoconstriction and isoprenaline-induced vasorelaxation, impaired endothelium-dependent vasodilatation and unchanged responsiveness to sodium nitroprusside. CLO treatment completely prevented endothelial deficiency, partly corrected the phenylephrine-induced vasoconstriction and did not affect the responses to isoprenaline and sodium nitroprusside in diabetic aorta. Diabetes also produced a marked decrease in the rate of spontaneously beating right atria and a significant increase in basal contractile force of left ventricular papillary muscle. The responsiveness of right atria to the positive chronotropic effect of isoprenaline was significantly decreased in diabetic rats, and was increased in CLO-treated diabetic rats. The positive chronotropic effect of noradrenaline was markedly increased in diabetic atria, but prevented by CLO treatment. Diabetes also resulted in an increased positive inotropic response of papillary muscle to both noradrenaline and isoprenaline, which were prevented by CLO treatment. CLO treatment also resulted in lower tissue sensitivity (pD(2)) to these agonists in diabetic papillary muscle. Ventricular hydroxyproline content was found to be unchanged among the experimental groups. The ultrastructure of diabetic myocardium displayed various degenerations (i.e. intracellular oedema, myofibrillar fragmentation, condensed pleomorphic mitochondria, thick capillary irregular basement membrane, swollen endothelial cells), which were partially prevented by CLO treatment. We conclude that the supplementation with CLO is effective in preventing cardiovascular disorders observed in experimental diabetes.

Dipeptidyl peptidase IV (DDP IV) in NASH patients.

OBJECTIVE(S): Non-alcoholic steatohepatitis (NASH) is a chronic liver disease with unknown etiology. The insulin resistance, immune mechanisms and oxidative stress are the main factors in its pathogenesis. Dipeptidyl peptidase IV (DPPIV) or CD26 is a protein with endocrine and immune functions. This study aimed to elicudate the changes related to DPPIV in NASH patients. METHODS: Serum and urinary DPPIV activities were measured in 31 NASH patients and 17 healthy controls. The liver biopsies of 29 patients were immunolabeled for CD26. RESULTS: The mean age of patients were 46 +/- 11 years and 14 (45%) of them were female. The serum DPPIV activity was higher in patients (57.3 +/- 7.8 U/L) than controls (43.6 +/- 10.6 U/L) (p < 0.0001), and correlated with the histopathological grade (p = 0.038, r = 0.373) and hepatosteatosis (p = 0.018, r = 0.423) but not with stage (p = 0.286), class (p = 0.286) or CD26 staining (p = 0.743). The urinary DPPIV activity was similar in patients (1.52 +/- 0.94 U/mmol creatinine) and controls (1.37 +/- 0.68 U/mmol creatinine) (p = 0.861). Three acinar zones of liver had equal CD26 expression (p = 0.076). The intensity of CD26 immunostaining was correlated with histopathological grade (p = 0.001) and hepatosteatosis (p = 0.003) but no correlation with stage or class could be detected (p = 0.610 and 0.956, respectively). In CONCLUSIONS: The serum DPPIV activity and the staining intensity of CD26 in liver are correlated with histopathologic grade of NASH and hepatosteatosis. DPPIV can be proposed as a novel candidate with several potential functions in NASH pathogenesis.

Effect of PUVA, narrow-band UVB and cyclosporin on inflammatory cells of the psoriatic plaque.

BACKGROUND: Because antigen presenting is necessary for T-cell activation, antigen-presenting cells should be involved in the pathogenesis of psoriasis. In this study, our purpose was to evaluate and compare effects of PUVA, cyclosporine A and narrow-band UVB on dendritic cells and activated lymphocytes in the psoriatic lesions. METHODS: Forty-five volunteered patients (15 patients in each treatment group as PUVA, cyclosporin A and narrow-band UVB) were enrolled in this study. Lesional skin biopsies were taken from each patient before and after treatments. Fresh frozen biopsies were studied for the expressions of CD1a, CD68, CD86, CD4, CD8 and HLA-DR proteins by immunohistochemistry. RESULTS: There was no correlation between severity of the lesions and expressions of the antigens. Only PUVA significantly decreased CD1a+ epidermal Langerhans cells' (LCs) counts. Treatment modalities decreased expression of costimulator CD86, and most of them decrease antigen-presenting capacity of skin by decreasing HLA class-II expression. CONCLUSIONS: All treatment modalities equally reduce lymphocytes, macrophages and dendritic cells. PUVA is the only treatment that decreases epidermal LCs. All treatments effectively diminish expression of CD86 and inhibit this step of inflammation.

Effects of ischemic preconditioning on rat lung: role of nitric oxide.

Recent studies suggest that ischemic preconditioning (IP) of the lung may have a protective effect in ischemia-reperfusion (I/R) injury. The purpose of the present study was to investigate the preconditioning hypothesis in rat pulmonary vascular bed and to examine the role of nitric oxide (NO) in IP. Isolated rat lung was perfused with Krebs-Henseleit solution containing indomethacin at a constant flow rate and perfusion pressure changes was recorded by a pressure transducer. In rat pulmonary vascular bed, 2 hours of hypothermic ischemia significantly attenuated histamine-induced vasodilator responses without affecting sodium nitroprusside (SNP) vasodilation when compared to sham values. However, 2 cycles of 5 minutes of ischemia and reperfusion that were applied prior to 2 hours of ischemia (IP protocol) prevented the attenuation of histamine-induced vasodilation. On the other hand, IP failed to prevent pulmonary edema after ischemia. Histopathological examination of rat lungs demonstrated that IP was able to protect endothelial cells and type II pneumocytes in lung. Moreover, in IP group, malondialdehyde (MDA) contents of the lung tissue were significantly lower and tissue glutathione (GSH) contents were significantly higher than those in I/R group. Administration of NO synthase inhibitor, N(G)-nitro-L-arginine-methyl ester (L-NAME) prior to the IP protocol abolished the protective effects of IP, but not affected the tissue malondialdehyde and glutathione levels. These results suggest that I/R impaired endothelium-dependent vasodilatory response, whereas endothelium-independent SNP-induced responses were preserved in rat pulmonary vascular bed. IP prevented the impairment of pulmonary vascular endothelium-dependent responses, and these effects may be partially mediated by NO.

Correlation of tissue selectin expression and hemodynamic parameters in rheumatic mitral valve disease.

BACKGROUND AND AIM OF THE STUDY: The study aim was to examine tissue expression of the adhesion molecules E-selectin and P-selectin on atrial, valvular and atrial myocardial blood vessel endothelium in patients with rheumatic mitral stenosis, and to investigate whether such expression was correlated with hemodynamics. METHODS: Thirteen patients (eight women, five men; mean age 51 +/- 10 years) with severe rheumatic mitral stenosis who underwent mitral valve replacement surgery were examined on preoperative day 1, using cardiac catheterization and echocardiography. Specimens from the mitral valve and left atrium of each patient were evaluated for CD 62E and CD 62P expression using indirect immunoperoxidase and immunofluorescence techniques RESULTS: A great majority of patients presented E and/or P selectin expression of variable intensity on atrial, valvular and atrial myocardial blood vessel endothelium. A more diffuse and stronger reaction for CD 62P was noted compared to that for CD 62E. The left ventricular end-diastolic diameter and left atrial diameter were positively correlated with endocardial CD 62P and CD 62E expression. Right atrial pressure was also strongly and positively correlated with endocardial expression of CD 62E (r = 0.80, p 0.03) and CD 62P (r = 0.8, p = 0.02). CONCLUSION: Marked tissue expression of CD 62E and CD 62P was identified on atrial, valvular and atrial myocardial blood vessel endothelium. Moreover, the degree of expression of adhesion molecules was significantly correlated with the left atrial and left ventricular chamber diameters, as well as right atrial pressure.

Focal segmental glomerulosclerosis associated with mitochondrial cytopathy: report of two cases with special emphasis on podocytes.

We report two children with focal segmental glomerulosclerosis (FSGS) associated with mitochondrial cytopathy (MC). Case 1 was diagnosed as MC with the findings of ptosis, ophthalmoplegia, failure to thrive, high serum lactate and pyruvate levels, ragged red fibers in muscle biopsy and the common 4.9 kb deletion in mtDNA when she was four years old. She subsequently developed FSGS four years later. Case 2 was a four month-old girl presenting with feeding difficulty from birth, with vomiting, seizures and nystagmoid eye movements, nephrotic proteinuria and hematuria. Renal biopsy revealed FSGS. Ultrastructural study demonstrated markedly pleomorphic mitochondria in podocytes with a severe effacement of foot processes. The analyses of muscle biopsy and skin fibroblasts for respiratory chain enzymes were found to be normal, while mitochondrial DNA analysis revealed the population of a single deleted mtDNA in the heteroplasmic state. The present cases illustrate FSGS as a rare renal complication of mitochondrial disease and provide further evidence of podocytes possessing abnormal mitochondria which may cause glomerular epithelial cell damage leading to glomerulosclerosis.

Histological comparison of alendronate, calcium hydroxide and formocresol in amputated rat molar.

The purpose of this study was to evaluate the potential of alendronate sodium (ALN), a biphosohonate to stimulate hard tissue formation in pulpotomized (amputated) rat molars. Two commonly used pulpotomy materials, calcium hydroxide (CH) and formocresol (FC) were utilized for comparisons. Histological evaluations were performed by observers blinded to treatment allocation on days 7, 15, 30 and 60, followed by statistical analysis of selected histological criteria. In all evaluation periods, hard tissue deposition was evident along the radicular dentin in ALN and CH groups. In days 30 and 60, the latter two groups showed no differences in inflammatory cell response and hard tissue deposition scores (P > 0.05). ALN appears to be capable of maintaining pulpal vitality, while promoting hard tissue formation, similar to CH.

Immunohistochemical analysis of CD71, CD98 and CD99 activation antigens in human palatine and nasopharyngeal tonsils.

OBJECTIVE: Tonsils (palatine and nasopharyngeal) are immunologically active tissues. Due to their anatomical location, they are considered to be the initial defense barrier against the antigens entering into the respiratory and gastrointestinal tract. Tonsils act against these antigens by producing and activating the lymphocytes, which are responsible for the immune response. In order to get information regarding the distribution of cell surface antigens on the epithelial, stromal and lymphoid cells of these organs, we performed immunohistochemical staining by using antibodies against CD99, CD71 and CD98 activation antigens. METHODS: Tissue samples of 20 patients undergoing tonsillectomy and adenoidectomy who presented with recurrent tonsillitis and adenoid hypertrophy in the Otorhinolaryngology Department, Hacettepe University Medical Faculty Hospital, Ankara, Turkey in 2001, were obtained as partial tissue samples apart from pathological examination. Tissues were immunostained by the indirect immunoperoxidase method. RESULTS: Strong CD71 reactivity in macrophages was observed as an indicator of the active role of the macrophages in immunoresponse in the chronic inflammation reaction. The CD98 reactivity on the proliferative basal layer of epithelium was a usual finding, as its detection in epithelial neoplasms and proliferative states is well known. We did not observe any reactivity of CD98 in nasopharyngeal tonsil epithelium and lymphoid cells of either nasopharyngeal or palatine tonsils. The CD99 reactivity was observed in the T-cell dependent area. CONCLUSION: We determined some topographic difference in the expression of some activation antigens in the epithelial, stromal and lymphoid components of the palatine and nasopharyngeal tonsils. Further detailed studies directed to determine the role of these antigens in tonsils would help to understand the role of these molecules in inflammatory events.

Fibroblastic reticular cells and fibroblast-like cells determined by monoclonal antibodies B-F45 and B-D46 in humans.

OBJECTIVE: Identification of stromal microenvironmental components of lymphoid organs is relatively harder at light microscopic level as few markers, which are mostly not very specific, are available to be used for such a purpose. We screened a large panel to determine monoclonal antibodies (mAbs) those reactive with fibroblasts/fibroblast-like cells aiming to obtain further evidence for the organization and function of this cell group. METHODS: Tissue samples of forty patients undergoing surgery in Otorhinolaryngology, Obstetrics and Gynecology, Orthopedics and Traumatology, Cardiovascular Surgery and General Surgery Departments, Hacettepe University Medical Faculty Hospital, Ankara, Turkey, due to different pathologies obtained as partial specimens of surgery which were apart from pathological examination were immunostained by indirect immunoperoxidase method in histology and embryology department in 2003. RESULTS: Among the screened monoclonal antibodies, monoclonal antibodies B-F45 and B-D46 reacted with the members of the family, therefore examined in detail in available human organs. Among the unique staining patterns of these mAbs, reactivity on fibroblastic reticular cells, perineural sheet cells pericryptal/perivillous fibroblasts were striking. CONCLUSION: Both mAbs will provide useful tools for further studies on stromal network of peripheral lymphoid organs and peripheral nerves.

Comparison of the effects of 1,25 dihydroxycholecalciferol and prostaglandin E2 on orthodontic tooth movement.

This study compared the effects of local administrations of prostaglandin E2 (PGE2) and 1,25-dihydroxycholecalciferol (1,25-DHCC) on orthodontic tooth movement in rats. Thirty-seven 6-week-old male Sprague-Dawley rats, weighing 160 +/- 10 g were used. Five rats served as the baseline control group. A fixed appliance system exerting 20 g of distally directed force was applied on the maxillary incisors of 32 animals for 9 days. Eight rats served as the appliance control group; 8 received a 20-microL injection of dimethyl sulfoxide (solvent for 1,25-DHCC) on days 0, 3, and 6; 8 received 20 microL of 10(-10) mol/L 1,25-DHCC on days 0, 3, and 6; 8 received a single injection of 0.1 mL of 0.1 microg PGE2 only on day 0. There was no significant difference in tooth movement between the PGE2 and the 1,25-DHCC groups. Both PGE2 and 1,25-DHCC enhanced the amount of tooth movement significantly when compared with the control group. The numbers of Howship's lacunae and capillaries on the pressure side were significantly greater in the PGE2 group than in the 1,25-DHCC group. On the other hand, the number of osteoblasts on the external surface of the alveolar bone on the pressure side was significantly greater in the 1,25-DHCC group than in the PGE2 group. Thus, 1,25-DHCC was found to be more effective in modulating bone turnover during orthodontic tooth movement, because its effects on bone formation and bone resorption were well balanced.

Structural and immunophenotypic characterization of high endothelial venules in rat and human tissue.

OBJECTIVE: To present additional data on high endothelial venule (HEV) structure and immunophenotype. METHODS: We used the zinc iodide-osmium tetroxide technique (ZIO), which is a metallophilic fixation and staining technique to examine HEVs at light and electron microscopic levels as this technique was previously reported to be reactive with cells in HEVs. Tonsils and lymph nodes were obtained from the Surgery and Otorhinolaryngology Departments, Hacettepe University Hospital, Ankara, Turkey during 2002 and 2003. An indirect immunohistochemical technique was used to examine frozen human tissue samples. RESULTS: Organelle rich high endothelial cells, sheet-like processes of pericytes surrounding HEVs, structural relation of pericyte processes with fibroblastic reticular cells, an unusual multivesicular body-like organelle within high endothelial cells were presented. Expression of a large panel of defined and yet non-defined antigens on HEVs are also presented using an indirect immunoperoxidase technique. CONCLUSION: Presence of some of these antigens on HEVs was previously reported while no previous report is available for others. Significance of the expression of these antigens in HEVs, structural hints for trans endothelial migration of lymphocytes and their travel along the reticular cell meshwork is briefly discussed.