Application of diffuse optical back reflection spectroscopy for determining articular cartilage thickness in a clinical setting.

PURPOSE: Develop a spectroscopic method to assess cartilage thickness during the arthroscopic examination. METHODS: Currently, arthroscopy assesses cartilage damage visually; outcomes are based on the surgeon's subjective experience. Light reflection spectroscopy is a promising method for measuring cartilage thickness based on the absorption of light by the subchondral bone. In the presented study, in vivo diffuse optical back reflection spectroscopic measurements were acquired by gently placing an optical fibre probe on different locations of the articular cartilage of 50 patients during complete knee replacement surgery. The optical fibre probe consists of two optical fibers with a diameter of 1 mm to deliver the light and detect back-reflected light from the cartilage. Centre to centre distance between the source and the detector fibers was 2.4 mm. Actual thicknesses of the articular cartilage samples were measured under microscopy using histopathological staining. RESULTS: Using half of the samples in the patient data, a linear regression model was formed to estimate cartilage thicknesses from the spectroscopic measurements. The regression model was then used to predict the cartilage thickness in the second half of the data. The cartilage thickness was predicted with a mean error of 8.7% if the actual thickness was less than 2.5 mm (R2 = 0.97). CONCLUSION: The outer diameter of the optical fibre probe was 3 mm, which can fit into the arthroscopy channel and can be used to measure the cartilage thickness in real-time during the arthroscopic examination of the articular cartilage.

Expressions of Notch signalling pathway members during early pregnancy in mice.

Although pregnancy is initiated and maintained through highly complex mechanisms, it is essential to understand the events that occur before and during early pregnancy to understand a healthy implantation process. The Notch signal, thought to be involved in this process, is frequently the subject of research with its different aspects. To better understand the role of Notch signaling in the peri-implantation period of the mouse uterus, we investigated the state of expression and localization of Notch 3, Notch 4, Rbp-J, Hes1, Hes7, Hey2, HeyL, and Fbw7 in the uterus and implantation sites in early pregnancy. Balb/C mice were divided into groups D1, D4, D5, D6, and D8. For D5 and D6 groups, implantation sites were identified by intravenous injection of Chicago blue. IHC, WB, and QRT-PCR methods were used. Notch 3 was very strong positive on the 4th day of pregnancy. Notch 4 was highly expressed on days 4, 5, 6, and 8 of pregnancy when P4 levels were high. Hes 1 level was at the lowest on the 4th day of pregnancy. Hes 7 protein expression gradually increased from D1 to D8 in the uteri and implantation sites. Hey 2 expression was at the highest level on the 1st and 4th days. Hey L expression was on the apical of the glands. Fbxw7 that expression was high on the 1st and 4th days of pregnancy. Notch signaling may play an essential role in regulating endometrial receptivity. In addition, our Hes7 results are new to the literature.

The investigation of apelin and apelin receptor expressions in mouse endometrium during peri-implantation period.

BACKGROUND: Fertilization, pre-implantation embryo development, implantation, and decidualization are critical for a healthy pregnancy. Successful implantation requires a competent blastocyst and a receptive uterus. Apelin was purified from the bovine stomach in 1998. Apelin receptor (APJ) is a member of G protein-coupled receptors. Apelin/APJ system's physiological role was shown in cardiovascular system, immune response, stress response, fluid regulation, nutrient uptake, angiogenesis, and adipoinsular axis; however, whether apelin/APJ system plays a role in implantation is unknown. In our study, we aimed to evaluate the localization and expressions of the apelin/APJ system in the peri-implantation period mouse uterus. METHODS: Uteri and implantation sites were collected from mice on the estrous phase and the 1st, 4th, 5th, 6th, and 8th days of pregnancy. Also, inter-implantation sites were collected from the 5th day of the pregnancy group. Localization and expressions of apelin and APJ were determined by immunohistochemistry and Western blot, respectively. RESULTS: Apelin and APJ were expressed in the luminal and gland epithelium, the stroma of all experimental groups. Two isoforms of apelin-8 and 16 kDa were detected by Western blot. While apelin expression increased from the estrous to the 8th day of pregnancy, APJ expression increased from the estrous to the 4th day of pregnancy, reached the highest expression level, then decreased. CONCLUSIONS: Our findings suggest that the apelin/APJ system might be involved in implantation and decidualization. Our findings will guide further studies and may help elucidate the underlying causes of implantation failure and pregnancy loss.

Antiandrogen abiraterone and docetaxel treatments affect Notch1, Jagged1 and Hes1 expressions in metastatic prostate cancer cells.

BACKGROUND: Prostate cancer is the most common cancer in men. A Notch signaling pathway is an important pathway in cell proliferation, differentiation, and fate. However, currently, the effects of abiraterone based-anti-androgene therapy and docetaxel, the most commonly used standard chemotherapy in prostate cancer treatment, on Notch signaling pathway are unknown. This study aimed to investigate the effects of abiraterone acetate and docetaxel on the expression of Notch1, Jagged1 and Hes1 in prostate cancer cell lines. METHODS: In vitro effects of abiraterone acetate and docetaxel were examined on Notch1, Jagged1, and Hes1 expression in LNCaP and PC3 PCa cell lines by immunofluorescence, Western blot, and qRT-PCR. MTT proliferation assay was used to evaluate cell proliferation and survival. RESULTS: We found that in the treatment of PC3 cells with abiraterone acetate, docetaxel, and their combination, only mRNA expressions of Notch1, Jagged1 and Hes1 were affected compared to control, but these expression differences were not observed in protein expression. In LNCaP cells, abiraterone acetate and the combination groups reduced Notch1 protein expression. All treatment groups did not alter Jagged1 expression compared to control, but significantly increased the Hes1 gene and protein expression. CONCLUSION: Our findings suggest that abiraterone and docetaxel treatments affects the expression of Notch signal pathway proteins. But these drugs especially cause significant upregulation in Hes1 expression in PCa cells. Therefore, co-application of Notch signaling inhibitors together with docetaxel and abiraterone chemotherapy, it was thought that decreased Hes1 expression could be stopped the deterioration of the prognosis of the patient.

The effect of apelin-13 on gastric ischemia/reperfusion injury: the roles of sensory nerves and vagus nerve.

Apelin is a peptide that plays a role in physiological processes such as angiogenesis, apoptosis, and proliferation. The aim of this study was to investigate the role of capsaicin-sensitive afferent neurons and vagus in the effect of apelin against ischemia/reperfusion (I/R) injury. The experimental groups were (1) control, (2) I/R, (3) apelin + I/R, (4) vagotomy + I/R, (5) vagotomy + apelin + I/R, (6) capsaicin + I/R, (7) capsaicin + apelin + I/R, (8) lorglumide + I/R, and (9) lorglumide + apelin + I/R. To test the potential gastroprotective effect of apelin-13, apelin-13 (2 mg/kg i.v.) was administered just before both ischemia and reperfusion. A vagotomy was performed 1 week before I/R in the vagotomized groups; capsaicin (125 mg/kg s.c.) was administrated 2 weeks before I/R in the capsaicin-treated groups and lorglumide (5 mg/kg i.p.) was administered 30 min before I/R in the lorglumide-treated groups. After I/R, a variety parameters in gastric tissue were analyzed. cfos expression was determined in brainstem samples. In the I/R group, the lesion index, myeloperoxidase activity, lipid peroxidation, nitric oxide, and tumor necrosis factor-α increased, and mucosal blood flow, prostaglandin-E2, and calcitonin gene related peptide decreased. Apelin prevented the damaging effects of I/R and increased cfos expression in brainstem areas. Vagotomy, capsaicin, and lorglumide largely eliminated the gastroprotective effects of apelin-13. This study showed that sensory nerves and the vagus play regulatory roles in apelin-induced gastroprotection. Cholecystokinin may play a role in the effect of apelin through sensory neurons.

The effect of GnRH antagonist cetrorelix on Wnt signaling members in pubertal and adult mouse ovaries.

Wide application of gonadotropin-releasing hormone (GnRH) agonists and antagonists for clinical purposes determines their effects on ovarian signaling pathways. Our study aimed to determine the localization, expression levels of Wnt signaling members in the pubertal and adult mouse ovary and the impact of GnRH antagonist cetrorelix on these signaling members. 0.5 mg/kg of cetrorelix was injected to 3-and 6-week-old mice for 2 weeks. At the end of injection, ovaries from 5 (5Ce)- to 8-week (8Ce)-old mice were embedded in paraffin for immunohistochemistry and homogenized for western blot to compare with control (5C-8C) and sham groups (5S-8S). WNT2 and WNT4 showed higher expression in thecal and stromal cells in adult mouse ovaries and only WNT4 expression was affected by cetrorelix. FZD1 was localized mainly in oocytes of pubertal ovaries and granulosa cells and oocytes of adult ovaries. FZD1 was reduced by cetrorelix in pubertal ovaries. FZD4 was abundantly localized in thecal and stromal cells of all groups and protein level was not affected by cetrorelix. LRP-6 was expressed mainly in oocytes and stromal cells of pubertal, oocytes of adult ovaries and its expression was reduced by cetrorelix in adult ovaries. CTNNB1 intensity in granulosa cells was the lowest in pubertal and the highest in adult ovaries and its expression was decreased by cetrorelix in adult ovaries. Cetrorelix affected the expression of specific members of the Wnt signaling depending on the developmental stage of mice, pointing out its possible interaction with gonadotropins during pubertal and adult stages.

Impact of intravesical hyaluronic acid treatment on bladder inflammation in interstitial cystitis rat model

ABSTRACT Objective: To evaluate the effect of intravesical hyaluronic acid (HA) treatment on inflammatory cells and the severity of inflammation in an interstitial cystitis rat model created with hydrogen chloride (HCL) via immunohistochemical studies and myeloperoxidase activity for the first time in the literature. Materials and Methods: A total of 30 adult female white Rattus Norvegicus rats were divided into 3 groups as the HCL group, hyaluronic acid treatment (HCL-HA) group and control group. Chemical cystitis was created by administering HCL(400 microL,10 mM) except control group. A single dose of intravesical HA(0.5 mL,0.8 mg/mL) was administered to the treatment group. The bladder tissues of all subjects were immunohistochemically stained. The cell surface markers were used to evaluate inflammatory cell infiltration. Mast cell activation and IL-6 was evaluated to assess the inflammation and severity of inflammation, respectively. Myeloperoxidase activity was measured as it shows neutrophil density. Statistical significance was accepted as P<0.05. Results: It was observed that there was rich monocyte, T lymphocyte, B lymphocyte, and Natural Killer cells infiltration and high IL-6 levels in the bladder tissue after the intravesical hydrogen chloride instillation, especially in the stroma layer(p<0.005). In the HCL-HA group, severity of inflammation had statistically significantly regressed to the levels of the control group(p<0.005). An increase was observed in the bladder myeloperoxidase activity of the HCL group compared to the other two groups(p<0.05). Conclusions: Single dose intravesical hyluronic acid instillation reduces inflammatory cell infiltration and the severity of bladder inflammation in the rat model of bladder pain syndrome/interstitial cystitis.

Impact of intravesical hyaluronic acid treatment on bladder inflammation in interstitial cystitis rat model.

OBJECTIVE: To evaluate the effect of intravesical hyaluronic acid (HA) treatment on inflammatory cells and the severity of inflammation in an interstitial cystitis rat model created with hydrogen chloride (HCL) via immunohistochemical studies and myeloperoxidase activity for the first time in the literature. MATERIALS AND METHODS: A total of 30 adult female white Rattus Norvegicus rats were divided into 3 groups as the HCL group, hyaluronic acid treatment (HCL-HA) group and control group. Chemical cystitis was created by administering HCL(400 microL,10 mM) except control group. A single dose of intravesical HA(0.5 mL,0.8 mg/mL) was administered to the treatment group. The bladder tissues of all subjects were immunohistochemically stained. The cell surface markers were used to evaluate inflammatory cell infiltration. Mast cell activation and IL-6 was evaluated to assess the inflammation and severity of inflammation, respectively. Myeloperoxidase activity was measured as it shows neutrophil density. Statistical significance was accepted as P<0.05. RESULTS: It was observed that there was rich monocyte, T lymphocyte, B lymphocyte, and Natural Killer cells infiltration and high IL-6 levels in the bladder tissue after the intravesical hydrogen chloride instillation, especially in the stroma layer(p<0.005). In the HCL-HA group, severity of inflammation had statistically significantly regressed to the levels of the control group(p<0.005). An increase was observed in the bladder myeloperoxidase activity of the HCL group compared to the other two groups(p<0.05). CONCLUSIONS: Single dose intravesical hyluronic acid instillation reduces inflammatory cell infiltration and the severity of bladder inflammation in the rat model of bladder pain syndrome/interstitial cystitis.

The role of apelin in the healing of water-immersion and restraint stress-induced gastric damage.

The objective of this study was to explore the role of apelin in the healing of gastric lesions induced by stress. Male Wistar rats were exposed to water immersion and restraint stress (WIRS) for 6 h with or without the apelin receptor antagonist F13A. The rats were killed on the 1st, 3rd, 5th or 10th day after the end of stress induction. Apelin and hypoxia-inducible factor-1α expression was increased on the 1st day after the end of stress exposure and was decreased daily thereafter. However, F13A retarded the healing of gastric lesions by preventing the improvement of mucosal blood flow, prostaglandin E2 production and vascular endothelial growth factor expression in rats exposed to WIRS. Additionally, F13A increased the gastric 4-hydroxynonenol + malondialdehyde content on the 1st and 3rd days after the end of stress induction but did not affect the change in gastric mucosal nitric oxide levels. In conclusion, apelin may be a regulatory protein involved in the healing mechanism of stress-induced gastric damage.

Medical ozone treatment ameliorates the acute distal colitis in rat.

PURPOSE: To investigate the effect of medical ozone treatment on the experimental acute distal colitis in rats. METHODS: Eighteen rats were randomly distributed into three equal groups; control, acute distal colitis (ADC) without and with medical ozone treatment. Rats in the control group were taken saline. ADC was performed by rectal way with 4% acetic acid in groups 2 and 3, and the group 3 was treated with medical ozone for three weeks both rectally and intraperitoneally. At the twenty second day the distal colons samples were obtained for malondialdehyde and myeloperoxidase, blood samples were obtained to measure the levels of TNF-α and IL-1ß levels. Histolopatological examination was evaluated with Ki-67, IL-1ß and VEGF immunostaining densities. RESULTS: There was significant increase in tissue MDA, MPO activity, TNF-α and IL-1ß after ozone administration. There was also a significant difference at immunostaining densities of histopathological examination. CONCLUSIONS: Medical ozone treatment ameliorated the experimental acute distal colitis induced by acetic acid in rats. Its possible effect is by means of decreasing inflammation, edema, and affecting the proliferation and the vascularization.

Effect of ozone on colon anastomoses in rat peritonitis model.

PURPOSE: To investigate the effects of medical ozone theraphy on the colon anastomosis of peritonitis model in rats. METHODS: Eighteen rats were randomly assigned into three equal groups; control, cecal punctuation and colon anastomosis and ozone theraphy. Sepsis was performed with a cecal punctuation in groups 2 and 3. The medical ozone theraphy was administered intraperitonealy for three weeks in group 3 while the other rats received saline injection. At the twenty second day serum were obtained for TNF-α and IL-1ß, the colonic burst pressures were measured and colonic tissue samples were obtained for MDA and MPO levels. Histolopatological examination was evaluated with H&E stain, and Ki-67, IL-1ß and the VEGF immunostaining densities were also compared. RESULTS: Intraperitoneal ozone administration reversed TNF-α, IL-1ß, MDA and MPO levels and the colonic burst pressures. There was also a significant difference at immunostaining densities of histopathological examination. CONCLUSION: Medical ozone therapy may contribute to tissue healing by affecting the proliferation and the vascularization thus has benefits on colonic anastomosis at peritonitis in rats.

Characterization of Notch Signalling Pathway Members in Normal Prostate, Prostatic Intraepithelial Neoplasia (PIN) and Prostatic Adenocarcinoma.

Prostate Cancer (PCa) holds the second place in terms of cancer-related mortality rate among men. The Notch signalling pathway regulates the proliferation and differentiation in embryonic and adult tissues and determines the cell fate. The body of knowledge in the present literature is currently controversial about the effect of the Notch pathway on prostatic cancer. Therefore, the present study aimed to examine the immunolocalization and expression levels of Notch1-4, Jagged1-2, Delta, HES1 and HES5 from among the members of the Notch signalling pathway in tissues of normal, prostatic intraepithelial neoplasia (PIN) and malignant prostate. The current study included a sample of 20 patients with localised prostatic adenocarcinoma, 18 patients with high grade PIN (H-PIN) and 18 normal prostatic tissue. Immunolocalisations of Notch1, 2, 3, 4, Jagged1, 2, Delta, HES1 and HES5 were identified through the immunohistochemical method. The findings of the present study showed that all in-scope members of the Notch signalling pathway were localised in PIN structures to a greater extent than in other tissues and from amongst these members, specifically Notch1, Notch4, Jagged1 and HES1 were at more significant levels. Consequently, the findings of the present study may indicate that the Notch signalling pathway can play a role especially in the formation of PIN structures.

The Effect of Phospholipids (Surfactant) on Adhesion and Biomechanical Properties of Tendon: A Rat Achilles Tendon Repair Model.

Adhesion of the tendon is a major challenge for the orthopedic surgeon during tendon repair. Manipulation of biological environment is one of the concepts to prevent adhesion. Lots of biochemicals have been studied for this purpose. We aimed to determine the effect of phospholipids on adhesion and biomechanical properties of tendon in an animal tendon repair model. Seventy-two Wistar rats were divided into 4 groups. Achilles tendons of rats were cut and repaired. Phospholipids were applied at two different dosages. Tendon adhesion was determined histopathologically and biomechanical test was performed. At macroscopic evaluation of adhesion, there are statistically significant differences between multiple-dose phospholipid injection group and Control group and also hyaluronic acid group and Control group (p < 0.008). At microscopic evaluation of adhesion, there was no statistically significant difference (p > 0.008). Ultimate strength was highest at hyaluronic acid injection group and lowest at multiple-dose phospholipid injection group. Single-dose phospholipids (surfactant) application may have a beneficial effect on the tendon adhesion. Although multiple applications of phospholipids seem the most effective regime to reduce the tendon adhesion among groups, it deteriorated the biomechanical properties of tendon.

Characterization of colony-forming cells in adult human articular cartilage.

Recent studies have shown that adult human articular cartilage contains stem-like cells within the native structure. In this study, we aimed to determine the localization of putative stem cell markers such as CD90, STRO-1, OCT-3/4, CD105 and CD166 in adult human articular cartilage tissue sections and demonstrate the expression of these markers within the expanded surface zone colony-forming (CF) cells and evaluate their differentiation potential. Biopsy samples were either fixed immediately for immunohistochemical analyses or processed for in vitro cell culture. Immunohistochemical and flow cytometry analyses were performed by using CD90, STRO-1, OCT-3/4, CD105 and CD166 antibodies. Isolated colony-forming (CF) cells were further stimulated, by using the appropriate growth factors in their pellet culture, to obtain cartilage, bone and adipose lineages. We observed that the expression of the stem cell markers were in various zones of the human adult cartilage. Flow cytometry results showed that in CF cells the expression of CD90 and CD166 was high, while OCT-3/4 was low. We also determined that CF cells could be stimulated towards cartilage, bone and adipose lineages. The results of this research support the idea that the resident stem-like cells in adult human articular cartilage express these putative stem cell markers, but further experimental investigations are needed to determine the precise localization of these cells.

[Does application time of alendronate sodium effect the spinal fusion in ovariectomized rats?]. / Alendronate sodyum uygulama zamani, ovariyektomi yapilmis siçanlarda spinal füzyon üzerine etkili midir?

OBJECTIVES: In this experimental study the effect of alendronate (Aln) sodium on spinal fusion, that was given preoperatively or postoperatively, was compared both mechanically and histologically in ovariectomized rats. The research question was "Does application time of alendronate sodium effect the spinal fusion in ovariectomized rats?''. MATERIALS AND METHODS: Fifty female Wistar rats with a mean weight of 200 g and an average age of 12 weeks were ovariectomized according to the standard procedure. The rats were randomized into three groups nine weeks after ovariectomy. Group 1: spinal arthrodesis and saline weekly for six weeks postoperatively; group 2: spinal arthrodesis and Aln sodium 1 µgr/kg/week for six weeks postoperatively; group 3: Aln sodium 1 µgr/kg/week for six weeks preoperatively, then one week later spinal arthrodesis was done. The rats were sacrificed six weeks after fusion surgery and their vertebrae were evaluated by manual palpation, mechanical testing machine and histomorphometric analysis. RESULTS: Fusion rates obtained by manual palpation were 50%, 17.6% and 55.5% in group 1, 2 and 3, respectively (p>0.05). Mean values of fusion tissues in mechanical evaluation were 498±20.7, 481±23.7 and 480±26.2 (MPa) accordingly (p>0.05). Compared with group 1, delayed endochondral ossification and more cartilage matrix among bone grafts were seen in group 2 and 3 in histological evaluation. CONCLUSION: Application time of the Aln sodium didn't significantly affect the lumbar spinal fusion rates in ovariectomized rats. In histological evaluation, delayed endochondral ossification was seen in Aln sodium-treated groups.

Distribution of CD105 and CD166 positive cells in the proximal epiphysis of developing rat humerus.

The expression of cell surface receptors, CD105 and CD166, are characteristic of mesenchymal stem cells in cartilage. However, there is limited data regarding their immunolocalization in the cartilage of developing rat epiphysis. The purpose of this study was to determine the presence of CD105 and CD 166 positive cells in the proximal epiphysis of developing rat humerus and specify their zonal distribution with age. The tissues of rat humerus were taken on embryonic day 15 (E15), embryonic day 19 (E19), postnatal day 10 (PN10), postnatal day 20 (PN20) and adult rats and studied for the immunolocalization of CD105 and CD166. Our results showed that CD105 and CD166 positive cells were scattered in early stages of development of humerus epiphysis. For E15, only the hypertrophic zone was positive, whereas for E19 almost all zones of the epiphysis were positively stained for these markers. For PN10 and PN20, the CD105 and CD166 positive cells were mainly localized on the surface of the articular cartilage. In adult articular cartilage the CD105 and CD166 positive cells were localized in the superficial and transitional zones and in the upper regions of the deep zone. Our study provides evidence that in the developing cartilage tissue the localization of CD105 and CD166 positive cells is both dynamic and stage dependent, which may imply the existence of stem cell-like cells in cartilage from an early age to adult.

Uterine FK506-binding protein 52 (FKBP52)-peroxiredoxin-6 (PRDX6) signaling protects pregnancy from overt oxidative stress.

Immunophilin FK506-binding protein 52 (FKBP52) is a cochaperone that binds to the progesterone receptor (PR) to optimize progesterone (P(4))-PR signaling. We recently showed that Fkbp52-deficient (Fkbp52(-/-)) mice have reduced uterine PR responsiveness and implantation failure which is rescued by excess P(4) supplementation in a genetic background-dependent manner. This finding led us to hypothesize that FKBP52 has functions in addition to optimizing PR activity. Using proteomics analysis, we found that uterine levels of peroxiredoxin-6 (PRDX6), a unique antioxidant, are significantly lower in Fkbp52(-/-) mice than in WT and PR-null (Pgr(-/-)) mice. We also found that Fkbp52(-/-) mice with reduced uterine PRDX6 levels are susceptible to paraquat-induced oxidative stress (OS), leading to implantation failure even with P(4) supplementation. The same dose of paraquat did not interfere with implantation in WT mice. Moreover, treatment with antioxidants alpha-tocopherol and N-acetylcysteine (NAC) attenuated paraquat-induced implantation failure in P(4)-treated Fkbp52(-/-) mice. Functional analyses using mouse embryonic fibroblasts show that Fkbp52 deficiency associated with reduced PRDX6 levels promotes H(2)O(2)-induced cell death, which is reversed by the addition of NAC or by forced expression of PRDX6, suggesting that Fkbp52 deficiency diminishes the threshold against OS by reducing PRDX6 levels. These findings provide evidence that heightened uterine OS in Fkbp52(-/-) females with reduced PRDX6 levels induces implantation failure even in the presence of excess P(4). This study shows that FKBP52-PRDX6 signaling protects pregnancy from overt OS.

Effects of formaldehyde inhalation on the junctional proteins of nasal respiratory mucosa of rats.

Exposure to formaldehyde, which is an organic compound, disturbs the integrity of nasal mucosa. In this study, we aimed to clarify the protein changes in the junctional complex of nasal mucosa of Wistar rats exposed to formaldehyde inhalation. The study was performed in 20 female Wistar rats. Rats were divided into two groups randomly. Control rats were allowed free access to standard rat chaw and tap water (n:10). Experimental group was exposed to formaldehyde vapor at 15ppm, 6h/day, 5 days/week for 12 weeks (n:10). Histological evaluation of the experimental model was determined by hematoxylin-eosin (HE) and periodic acid Schiff (PAS) stainings of paraffin-embedded nasal mucosa tissues and by electron microscopy. The effects of formaldehyde inhalation on the distribution of occludin, E-cadherin, and gamma-catenin were assessed by immunohistochemistry. The nasal mucosa of the experimental group was correlated with hypertrophy in goblet cell, degeneration in basal lamina, stratification of epithelium, and proliferation. Thickness of basal lamina and also local degenerative regions, vacuole increase in cytoplasmic areas, irregular forms of kinocilium and loss of sharpness in the kinocilium membrane were the findings at the ultrastructural level. The expressions of E-cadherin, occludin, gamma-catenin proteins in intercellular junctional complexes of rat nasal mucosa were also decreased in experimental group compared to control group. The findings of the present study indicated that formaldehyde vapor inhalation in the concentrations and duration of exposure used in the present experiment significantly decreased the density of structural proteins of the junctional complex in the nasoepithelium. It was suggested that, the formaldehyde inhalation could cause complete impairment of intercellular junctional complexes and disturb the tissue integrity in nasal mucosa at higher concentrations.

The immunohistochemical localization of notch receptors and ligands in human articular cartilage, chondroprogenitor culture and ultrastructural characteristics of these progenitor cells.

The presence of progenitor/stem cells in human articular cartilage remains controversial. Therefore, we attempted to isolate and culture progenitor/stem cells and to investigate their phenotypic characteristics. Biopsies were obtained (with consent) from patients undergoing arthroscopic surgery. Full depth explants were fixed and cryosectioned or enzymatically digested and the resulting cells cultured and plated on fibronectin-coated dishes. Chondrocytes were cultured until colonies of >32 cells were present. Colonies were trypsinized and expanded in monolayer for pellet culture. Immunolocalization of Notch and its ligands were detected in vivo and in vitro using immunocytochemistry. In vitro studies investigated differences in immunolocalization of Notch and its associated ligands in colony-forming cells and small clusters of non-colony-forming cells. The ultrastructure of the chondroprogenitors was examined by scanning and transmission electron microscopy. Results revealed that the immunolocalization of Notch-1 and its ligand Delta were concentrated in regions closest to the articular surface. Notch-1 was also densely localized in the deeper zone of articular cartilage. Notch-2 immunolabeling was densely localized in all zones of articular cartilage. Jagged-1 was concentrated in the deeper regions of articular cartilage. Notch-1, Delta and Jagged-1 were more abundant in colony-forming cells than non-colony-forming chondrocytes in vitro. Notch-3, Notch-4 and Jagged-2 were absent from all regions of the articular cartilage tissues and cultured cartilage cells in vitro. Ultrastructurally, chondrocytes cultured in monolayer dedifferentiated to fibroblast-like cells with cell surface processes of varying lengths, pellet cultured cells varied in morphology, as flattened and rounded. In conclusion, we propose that adult human articular cartilage may contain cells having progenitor cell features.

Anterior intermeniscal ligament: an ultrastructural study.

The aim of the present study was to investigate the detailed histological characteristics of membranous and cord-like anterior intermeniscal ligaments (AIMLs) by transmission electron microscopy (TEM) and light microscopy. Ten biopsies of AIMLs were sampled from 10 knees during total knee arthroplasty procedures. Three of them were membranous and 7 of them were cord-like. They were processed for light and TEM evaluations. Histologically, the findings in the membranous and cord-like ligaments were similar. They consisted of parallel bundles of collagen fibrils and their posterior surfaces were covered by a layer of loose well-vascularized synovial tissue. The subsynovial region consisted of loose connective tissue and was rich in blood vessels and nerve endings. Fibroblasts embedded between parallel-oriented collagen fibrils were the major cell type that we observed. Free nerve endings were squeezed between bundles of collagen fibers. Electron microscopic observations revealed the presence of Ruffini corpuscles. The presence of neural mechanoreceptors in the membranous and cord-like intermeniscal ligaments may contribute to structural and proprioceptional function of the knee. Protection of those ligaments may be valuable in planning and performing meniscal surgeries.