Number Of Epithelial Layers Research Articles

CHARACTERISTICS OF THE GINGIVAL EPITHELIUM OF CHILDREN’S THIRD MOLARS AT DIFFERENT STAGES OF ROOT FORMATION

Extraction of impacted and dystopic third molars is a rather traumatic manipulation accompanied by a large bone defect and wound infection. Therefore, it is advisable to perform hermectomy, which has a number of advantages over typical and atypical methods of tooth extraction. An important stage of any surgical intervention is the postoperative period, which is characterized by a certain duration and the presence of complications, which is due, among other things, to the regenerative potential of tissues, especially epithelial tissues. Aim of the study is to evaluate the condition of the gingival epithelium in the area of third molars in children who have to have these teeth extracted for orthodontic reasons, taking into account the stage of tooth formation, i. e. its root.Material and Methods. Third molar extraction for orthodontic indications was performed in 95 children aged 11 to 18 years.Clinical and radiologic examinations were performed in three groups: Group I (n=30) – children aged 11-13 years; Group II(n=35) – children aged 13-16 years, and Group III (n=30) – children aged 16-18 years. During surgery, gingival tissue was taken from the adjacent areas for examination. The material was fi xed, dehydrated, and paraffi n- embedded for histologic processing. Immunohistochemical techniques were performed according to the manufacturer’s protocols. Specifi cally, immunohistochemical detection of Ki-67 antigen was performed with primary antibodies against it. Digital copies of the images were analyzed using the specialized computer program ImageJ v1.52 (freeware, USA). The obtained digital data were statistically processed.The digital data obtained were statistically processed. A preliminary test for normality of the distribution was carried outusing the Shapiro- Wilks method. According to this criterion, the hypothesis of normality of the distribution was not rejectedfor all the statistical samples studied (at the signifi cance level of p=0.05), so we used mainly parametric methods of statistical analysis: calculation of the arithmetic mean and its error, unpaired two-sided Student’s t-test. However, because the statistical samples were small, the non-parametric Mann- Whitney test was used in addition to the Student’s t-test.The study was conducted as part of the complex research work of the Department of Pediatric Dentistry of the Bukovinian State Medical University on the topic «Development of methods of prevention and treatment of the main dental diseases in children, taking into account the risk factors of their development» (state registration number: 0121U110122). The conducted research complied with bioethical norms, as stated in the conclusions of the Bioethics Commission of the Bukovinian State Medical University (№ 1 dated 17.09.2020).Conclusions. Thus, the histological and immunohistochemical study of the gingiva in the area of the third molar allows usto conclude that during the formation of the root of this tooth, a number of changes occur in the epithelial cover of the gingiva, namely: an increase in the number of epithelial layers with a decrease in their proliferative activity. The obtained data indicate a decrease in the regenerative potential of the multilayered squamous epithelium with increasing age of the child and the degree of third molar formation, which is refl ected in the clinical picture of the course of surgical intervention.

Relationship between promoting effect of Zuogui Pills on angiogenesis of reproductive organs and mobilization factors GM-CSF, SDF-1, and their receptors of EPCs in early-aging rats

This study aimed to investigate the relationship between the promoting effect of Zuogui Pills on ovarian and vaginal angiogenesis in early-aging rats and mobilization factors granulocyte-macrophage colony-stimulating factor(GM-CSF), stromal cell-derived factor-1(SDF-1), and their receptors of endothelial progenitor cells(EPCs) and explore the mechanism of Zuogui Pills in improving reproductive hypofunction in early-aging rats. Ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS) was used to analyze the chemical components of the extract of Zuogui Pills. Forty 14-month-old female early-aging rats with estrous cycle disorder were randomly divided into a blank group, a conjugated estrogen group(conjugated estrogen suspension, 65 μg·kg~(-1)), and low-(11 g·kg~(-1)) and high-dose(33 g·kg~(-1)) Zuogui Pills groups, with 10 rats in each group. In addition, 10 4-month-old female rats were assigned to the youth control group. The rats in the blank group and the youth control group were treated with 20 g·kg~(-1) distilled water by gavage, while those in the groups with drug intervention were treated with corresponding drugs by gavage, once a day for 15 days. Enzyme-linked immunosorbent assay(ELISA) was used to detect the levels of SDF-1 and GM-CSF in the mobilization of EPCs in serum. Hematoxylin-eosin(HE) staining was used to observe the changes in the number of ovarian follicles at all levels and corpus luteum, the number of vaginal epithelial layers, the number of vaginal folds, and the blood vessels of ovarian and vaginal tissues in the groups with drug intervention. Western blot was used to detect the expression of ER, GM-CSFR, CXCR4, and CXCR7 proteins in ovarian and vaginal tissues. As revealed by the results, the blank group showed decreased number of corpus luteum, gro-wing follicles at all levels, and blood vessels(P<0.05), decreased thickness of vaginal mucosa, the number of epithelial layers, the number of vaginal folds, and the number of vessels in the lamina propria(P<0.05), reduced content of SDF-1 and GM-CSF in the peripheral blood(P<0.05), and down-regulated levels of ER, CXCR4, CXCR7, and GM-CSFR proteins in ovarian and vaginal tissues(P<0.05). The groups with drug intervention showed increased number of growing follicles at all levels, corpus luteum, and blood vessels(P<0.05), decreased number of atresia follicles(P<0.05), increased thickness of vaginal mucosa, the number of epithelial layers, the number of vaginal mucosal folds, and the number of blood vessels in the lamina propria(P<0.05), increased content of SDF-1 and GM-CSF in the peripheral blood(P<0.05), and up-regulated levels of ER, CXCR4, CXCR7, and GM-CSFR proteins in ovarian and vaginal tissues(P<0.05). This experiment suggests that Zuogui Pills may promote ovarian and vaginal angiogenesis and improve the reproductive function of early-aging rats by up-regulating the levels of mobilization factors SDF-1, GM-CSF, and their receptors of EPCs.

Infigratinib, a Selective Fibroblast Growth Factor Receptor Inhibitor, Suppresses Stent-Induced Tissue Hyperplasia in a Rat Esophageal Model.

Stent-induced tissue hyperplasia remains a challenge for the application of self-expanding metal stents in the management of esophageal stricture. This study aimed to evaluate the efficacy of infigratinib, which is a selective fibroblast growth factor receptor inhibitor, in the prevention of stent-induced tissue hyperplasia in a rat esophageal model. Twenty-four male Sprague-Dawley rats underwent esophageal stent placement and were randomized to receive 1ml of vehicle, 5mg/kg infigratinib in 1ml of vehicle, or 10mg/kg infigratinib in 1ml of vehicle via naso-gastric tube once daily for 28days. Follow-up fluoroscopy was performed on postoperative day 28, and the stented esophageal tissues were harvested for histological and immunofluorescence examinations. All rats survived until euthanasia on postoperative day 28 without procedure-related adverse events. The incidence of stent migration was 12.5%, 12.5% and 25% in the control group, the 5mg/kg infigratinib group and, the 10mg/kg infigratinib group, respectively. The percentage of granulation tissue area, the submucosal fibrosis thickness, the number of epithelial layers, the degree of inflammatory cell infiltration, the degree of collagen deposition, the number of fibroblast growth factor receptor 1 (FGFR1)-expressing myofibroblasts, and the number of proliferating myofibroblasts were all significantly lower in both infigratinib groups than in the control group (P < 0.05) but were not significantly different between the two infigratinib groups (P > 0.05). Infigratinib significantly suppresses stent-induced tissue hyperplasia by inhibiting FGFR1-mediated myofibroblast proliferation and profibrotic activities in a rat esophageal model.

Underdiagnosis of cervical intraepithelial neoplasia by colposcopy and its association with thin high‑grade squamous intraepithelial lesions.

The relationship between the thickness of the epithelium and the colposcopic diagnosis is controversial. The present study was conducted to determine whether colposcopic underdiagnosis of cervical intraepithelial neoplasia (CIN) is associated with thin high-grade squamous intraepithelial lesions (HSILs) of the cervix. A total of 136 cases of HSIL verified by pathological biopsy at Peking University People's Hospital between June and October 2021 were retrospectively analyzed; 79 cases were CIN2 and 57 cases were CIN3. The number and thickness of epithelial layers were analyzed using colposcopic impressions. In the low-grade colposcopic impression group, the number of epithelial layers (12.8±4.2 vs. 17.8±4.2) and epithelial thickness (105.2±41.9 µm vs. 150.3±50.0 µm) of CIN2 lesions were significantly lower compared with the high-grade colposcopic impression group; however, the differences for CIN3 were not statistically significant. CIN2 lesions had significantly fewer (12.8±4.2 vs. 17.2±5.4) and thinner (105.2±41.9 µm vs. 140.4±48.6 µm) epithelial layers than CIN3 lesions in the low-grade colposcopic impression groups. In the high-grade colposcopic impression group, however, there were no significant differences in the number or thickness of epithelial layers between CIN2 and CIN3. In 12 cases of thin HSILs, 91.6% of the colposcopic impressions were low-grade. Thin HSILs are likely associated with underdiagnosed colposcopic findings, particularly for CIN2. Thin HSILs usually present with small to minute lesions and lack the typical colposcopic appearance of classic HSIL, which may help to explain why thin HSILs are easily underestimated under colposcopy.

Comparison of three kinds of self-expandable metallic stents induced granulation tissue hyperplasia in the rabbit trachea

To compare stent-induced granulation tissue hyperplasia of bare (SEMS), polyurethane-covered (PU-SEMS) and electrospun nanofibre-covered (EN-SEMS) self-expandable metallic stents in the rabbit trachea. Twenty-seven rabbits were randomly assigned to 3 groups that received SEMS, PU-SEMS or EN-SEMS. Computed tomography and sacrifice were performed as scheduled. Haematoxylin–eosin and Masson’s trichrome staining protocols were performed for pathological analysis. The data for tracheal ventilation area ratio, qualitative histological scoring, number of epithelial layers, and thicknesses of papillary projection and submucosa were documented and statistically analysed. All stents were successfully placed under the guidance of fluoroscopy without complications. Post-stenting 3 and 7 days, computed tomography revealed that the fully expandable EN-SEMS was similar to the SEMS and PU-SEMS. The mean stented tissue score in the SEMS group was higher than those of both the PU-SEMS and EN-SEMS groups at 3 days post-stenting. The pathological findings suggested that there was no papillary projection formation 3 days after stent placement. The thickness of papillary projection in the SEMS group was significantly higher than those of the PU-SEMS and EN-SEMS groups at 7 days post-stenting. After stenting 4 weeks, the tracheal ventilation area ratio of SEMS, PU-SEMS and EN-SEMS was 0.214 ± 0.021, 0.453 ± 0.028 and 0.619 ± 0.033, respectively. There were significant between-group differences. In conclusion, the stent-induced granulation tissue formation in EN-SEMS is less severe than that of PU-SEMS and SEMS. EN-SEMS has smaller radial force, and the tracheal ventilation ratio after stent placement better than that of PU-SEMS.

Silver nanoparticle-coated self-expandable metallic stent suppresses tissue hyperplasia in a rat esophageal model.

To evaluate the efficacy of a silver nanoparticle (AgNP)-coated self-expandable metallic stent (SEMS) for suppressing tissue hyperplasia in a rat esophageal model. Twenty-four male Sprague-Dawley rats were randomly assigned to four groups. Animals in group A underwent uncoated SEMS placement, whereas animals in groups B, C, and D underwent 6, 12, and 24mg/mL AgNP-coated SEMS placement, respectively. All animals were euthanized 4weeks after SEMS placement, and a gross examination and histological analyses were performed. All rats achieved technical success and survived until the end of the study. The gross examination showed moderate to severe tissue hyperplasia in 5 rats in group A and 2 rats in group B. In contrast, no animals in groups C and D had moderate or severe tissue hyperplasia. The gross examination revealed no complications. The percentage of granulation tissue area, number of epithelial layers, thickness of submucosal fibrosis, percentage of connective tissue area, inflammatory cell infiltration grade, degree of collagen deposition, and degrees of Ki67, TUNEL, and α-SMA-positive deposition were significantly lower in groups C and D than in group A (all p < 0.05). However, only the percentage of granulation tissue area, number of epithelial layers, thickness of submucosal fibrosis, and percentage of connective tissue area were significantly lower in group B than in group A (all p < 0.05). No histological parameters were significantly different between group D and group C (all p > 0.05). AgNP-coated SEMSs suppressed tissue hyperplasia in a rat esophageal model.

Balloon-Expandable Biodegradable Stents Versus Self-Expandable Metallic Stents: A Comparison Study of Stent-Induced Tissue Hyperplasia in the Rat Urethra

To compare the degrees of stent-induced tissue hyperplasia of balloon-expandable, biodegradable stents (BEBSs) with those of self-expandable metallic stents (SEMSs) in a rat urethral model. A total of 20 rats were randomized into two groups. The BEBS group (n = 10) received a poly-l-lactic acid (PLLA) biodegradable stent. The SEMS group (n = 10) received a nitinol bare stent. All rats were killed eight weeks after stent placement. The degree of stent-induced tissue hyperplasia was assessed by comparing the results of retrograde urethrography and histologic examination between the two groups. Stent placement was technically successful in all rats. Two rats in the BEBS group were excluded due to procedure-related death. The mean luminal diameter of stented urethra on urethrograms was not significantly different at 4 and 8 weeks between the two groups. On histologic analysis, the percentage of granulation tissue area (p < 0.001) and the thickness of papillary projection (p < 0.001) were significantly higher in the BEBS group compared with the SEMS group. The inflammatory cell infiltration showed a clear tendency to significance (p = 0.050). There were no statistical differences in the number of epithelial layers and the thickness of submucosal fibrosis between the two groups. Formation of stent-induced tissue hyperplasia was significantly evident in the rat urethra with similar degrees between the BEBS and the SEMS. The BEBS was associated with a thicker papillary projection and larger granulation tissue area resulting from higher inflammation compared with the SEMS.

EW-7197 eluting nano-fiber covered self-expandable metallic stent to prevent granulation tissue formation in a canine urethral model

PurposeTo evaluate an EW-7197-eluting nanofiber-covered stent (NFCS) for suppressing granulation tissue formation after stent placement in a canine urethral model.Materials and methodsAll experiments were approved by the committee of animal research. A total of 12 NFCSs were placed in the proximal and distal urethras of six dogs. Dogs were divided into two groups with 3 dogs each. The control stent (CS) group received NFCSs and the drug stent (DS) group received EW-7197 (1000 μg)-eluting NFCSs. All dogs were sacrificed 8 weeks after stent placement Histologic findings of the stented urethra were compared using the Mann-Whitney U test.ResultsStent placement was technically successful in all dogs without procedure-related complications. On urethrographic analysis, the mean luminal diameter was significantly larger in the DS group than in the CS group at 4 and 8 weeks after stent placement (all p < 0.001). On histological examination, mean thicknesses of the papillary projection, thickness of submucosal fibrosis, number of epithelial layers, and degree of collagen deposition were significantly lower in the DS group than in the CS group (all p < 0.001), whereas the mean degree of inflammatory cell infiltration was not significantly different (p > 0.05).ConclusionThe EW-7197-eluting NFCS is effective and safe for suppressing granulation tissue formation after stent placement in a canine urethral model.

EW-7197, an activin-like kinase 5 inhibitor, suppresses granulation tissue after stent placement in rat esophagus

Self-expanding metallic stent (SEMS) placement is a well-established method for treating malignant esophageal strictures; however, this procedure has not gained widespread acceptance for treating benign esophageal strictures because of granulation tissue formation. The aim of the present study was to investigate whether EW-7197, a novel per-oral transforming growth factor-β type I receptor kinase inhibitor, suppressed granulation tissue formation after SEMS placement in the rat esophagus. Sixty rats underwent SEMS placement and were randomly divided into 4 groups. Group A (n= 20) received vehicle-treated control for 4 weeks. Group B (n= 20) received 20 mg/kg/day EW-7197 for 4 weeks. Group C (n= 10) received 20 mg/kg/day EW-7197 for 4 weeks followed by vehicle-treated control for 4 weeks. Group D (n= 10) received 20 mg/kg/day EW-7197 for 8 weeks. SEMS placement was technically successful in all rats. Eleven rats, however, were excluded because of stent migration (n= 9) and procedure-related death (n= 2). The luminal diameter in group A was significantly smaller than those in groups B, C, and D (all P< .001). The percentage of granulation tissue area, number of epithelial layers, thickness of submucosal fibrosis, percentage of connective tissue area, and degree of collagen deposition were significantly higher in group A than in groups B, C, and D (all P< .001); however, there were no significant differences among groups B, C, and D. EW-7197 decreased the expression levels of phospho-Smad 3, N-cadherin, fibronectin, α-smooth muscle actin, and transforming growth factor-β1 and increased the expression level of E-cadherin (all P< .01). EW-7197 suppressed granulation tissue formation after SEMS placement in the rat esophagus.

Loss of corneal epithelial heparan sulfate leads to corneal degeneration and impaired wound healing.

Heparan sulfate (HS) is a highly modified glycosaminoglycan (GAG) bound to a core protein to form heparan sulfate proteoglycans (HSPGs) that are vital in many cellular processes ranging from development to adult physiology, as well as in disease, through interactions with various protein ligands. This study aimed to elucidate the role of HS in corneal epithelial homeostasis and wound healing. An inducible quadruple transgenic mouse model was generated to excise Ext1 and Ndst1, which encode the critical HS chain elongation enzyme and N-deacetylase/N-sulfotransferase, respectively, in keratin 14-positive cells upon doxycycline induction. EXT(Δ/ΔCEpi) mice (deletion of Ext1 in corneal epithelium) induced at P20 presented progressive thinning of the corneal epithelium with a significant loss in the number of epithelial layers by P55. EXT(Δ/ΔCEpi) mice presented tight junction disruption, loss of cell-basement membrane adhesion complexes, and impaired wound healing. Interestingly, EXT(Δ/ΔCEpi) and NDST(Δ/ΔCEpi) mice presented an increase in cell proliferation, which was assayed by both Ki67 staining and 5-ethynyl-2'-deoxyuridine (EdU) incorporation. Moreover, EXT(Δ/ΔCEpi) mice presented compromised epithelial stratification 7 days after a debridement wound. The conditional knockout of HS from keratocytes using the keratocan promoter led to no corneal abnormalities or any disruption in wound healing. Corneal epithelial cells require HS for maintaining corneal homeostasis, and the loss of epithelial HS leads to both impaired wound healing and impaired corneal stratification.

Oral Low-Molecular Weight Hyaluronic Acid in the Treatment of Atrophic Vaginitis

The aim of this study was to evaluate the effectiveness of low molecular weight hyaluronic acid oral tablets for the treatment of atrophic vaginitis. 12 women with atrophic vaginitis were recruited for this double blind, placebo-controlled study. Patients were randomized to receive either low molecular weight hyaluronic acid (HA) oral tablets or placebo for three months. Vaginal biopsies were taken at baseline and after three months of treatment, and vaginal epithelium was analysed using light microscopy. The evaluation of symptoms was self-assessed by the patients. Biopsies from HA group showed an epithelium thicker than in placebo group. The lamina propria from the HA group also showed a denser appearance compared to placebo group. Morphometric analysis showed significant differences between HA and baseline in the number of epithelial layers and in the thickness. The evaluation of symptoms also showed an effective improvement in the patients treated with HA, compared to baseline and to placebo group. In conclusion, oral administration of HA tablets improved the vaginal epithelium, decreasing atrophy. This can be an ideal option for patients with atrophic vaginitis who do not want to or can not take estrogen and show low compliance toward vaginal administration.

Chemopreventive Effect of Lagenaria siceraria in Two Stages DMBA Plus Croton Oil Induced Skin Papillomagenesis

Cancer chemoprevention is a dietary or therapeutic strategy to prevent, suppress, or delay carcinogenesis either at initiation or progression level with nontoxic agents. Use of natural dietary compounds has been a major chemopreventive approach to modulate tumorigenic pathways. In the present study, we have evaluated Lagenaria siceraria (bottle gourd), a common vegetable of Indian household for its chemomodulatory potential. The fruit has been used in traditional medicine for a very long time for health benefits and to cure pain, ulcers, fever, cough, asthma, and other bronchial disorders. However, despite its reported beneficial effect the chemo modulatory potential of this plant has not been reported. Therefore chemopreventive effect of bottle gourd juice (BGJ) was studied against 7,12-dimethylbenz(a)anthracene (DMBA) plus croton oil induced skin papillomagenesis in Swiss albino mice. The effect was studied both at antiinitiation and antiinitiation/promotion level followed by histopathological study. A dose of 2.5% and 5% given in drinking water showed significant decrease in papilloma number, papilloma incidence, papilloma multiplicity, papilloma latency, papilloma volume, and papilloma size in different size range. Histopathological study showed chemopreventive effect by minimizing loss of stratification, a decrease in number of epithelial layers, reducing dermal infiltration and protection for various cytoplasmic changes. Higher dose of BGJ was found to be more effective than lower dose and the chemopreventive effect was maximum for antiinitiation/promotion treatment. Altogether, this study reports the chemopreventive effect of Lagenaria siceraria on skin papillomagenesis for the first time and suggests that its consumption may help in suppression of skin cancer.

Evaluation of Formation of Granulation Tissue Caused by Metallic Stent Placement in a Rat Urethral Model

To evaluate the feasibility of metallic stent placement and the formation of granulation tissue caused by stent placement in a rat urethral model. A bare self-expanding metallic stent was inserted in the urethra under fluoroscopic guidance in 20 male Sprague-Dawley rats. Ten rats were euthanized at 4 weeks (group A), and the other 10 were euthanized at 8 weeks after stent placement (group B). Stenosis diameter, number of epithelial layers, degree of inflammatory cell infiltration, thickness of submucosal fibrosis, and percentage of granulation tissue area were assessed. Stent placement was technically successful in all rats. Urethrograms showed perforation in three rats, partial migration in three, and stone formation in four. Granulation tissue formation was observed in all rats at the stent-implanted urethra, and the average percentage of granulation tissue area accounted for 41% and 45% of the original urethral lumen area in groups A and B, respectively. Urethrograms and urethral specimens showed significantly less stenosis diameter, less thickness of submucosal fibrosis, and lower percentage of granulation tissue area in the proximal urethra than in the distal urethra in both groups (P < .05). Histologic results demonstrated significantly fewer epithelial layers in group B compared with group A (P = .028). Placement of a self-expandable metallic stent proved to be feasible in the rat urethra and an efficient approach to stimulate granulation tissue formation as a potential model for reproducing the mechanisms of restenosis.

Changes in the histomorphology of the canine cervix through the oestrous cycle

The importance of canine reproduction is steadily increasing and little is known about the canine cervix so far. The aim of this study was to describe the histomorphology of the canine cervix and to determine its correlation to the stage of oestrous cycle and to circulating concentrations of progesterone (P4) and estradiol-17beta (E2), respectively. Ovariohysterectomy (OHE) was performed in 33 non-pregnant, healthy, intact bitches in defined stages of oestrous cycle (proestrus N = 5, estrus N = 7, early diestrus N = 5, late diestrus N = 11, anestrus N = 5). The entire cervix was collected for histological evaluation of the epithelial layer (number of layers, thickness), the stroma (number of layers, thickness, density, structure, and distribution of elastic fibres) and the average area and density of cervical glands as well as blood vessels. These parameters were evaluated in all the three parts of the cervix (cranial, middle, and caudal or vaginal part). The cervix showed the typical structure with a superficial epithelium, a lamina propria with cervical glands and vascular structures and a tunica muscularis below. Folds in the superficial epithelium were only observed in 54% females (N = 18). Epithelial thickness (P < 0.0001), number of glands (P < 0.05), mean area of glands (P < 0.0001), mean area of venous vessels (P < 0.0001), number of arterial vessels (P = 0.02), number of mast cells and number of eosinophilic granulocytes per mm 2 (P < 0.01) were significantly influenced by the stage of cycle. The following factors were significantly influenced by the localisation: number of epithelial layers (P < 0.0001), thickness of stroma (P < 0.0001) and mean number of glands (P < 0.01). Only mean area of venous vessels was significantly influenced by the stage of cycle and the localisation (P < 0.01). Besides, P4 was significantly correlated to number of glands per mm 2 (P < 0.0001), mean area of venous vessels (P < 000.1) and number of mast cells (P < 0.01). This study provided detailed information about the histomorphological structure of the cervix in non-pregnant bitches and showed that the cervix undergoes cyclic changes during the canine oestrous cycle, in particular in association with circulating progesterone concentration.

IN-1233, an ALK-5 Inhibitor: Prevention of Granulation Tissue Formation after Bare Metallic Stent Placement in a Rat Urethral Model

To evaluate the efficacy of an activin receptor-like kinase-5 inhibitor, IN-1233, for the prevention of tissue hyperplasia after bare stent placement in a rat urethral model. Procedures were performed in accordance with the National Institutes of Health guidelines for humane handling of animals; approval of the committee of animal research was obtained. In 20 Sprague-Dawley male rats (weight range, 300-350 g), a self-expanding metallic bare stent was inserted in the urethra by using fluoroscopic guidance. One group of 10 rats (group A) was treated with IN-1233, the other group of 10 rats (group B) received no treatment. Retrograde urethrography was performed 4 and 8 weeks after stent placement. All rats were sacrificed at 8 weeks for histologic analysis. Stent placement was technically successful in all rats. The average stent diameter was significantly larger in group A compared with group B at follow-up retrograde urethrography performed 4 (P = .006) and 8 (P < .001) weeks after stent placement. At histologic analysis, the percentage of granulation tissue area (P < .001), thickness of submucosal fibrosis (P < .001), and number of epithelial layers (P < .001) were significantly decreased in group A compared with group B. Inflammatory cell infiltration (P < .001) was significantly increased in group A compared with group B. IN-1233 is effective for the prevention of granulation tissue formation after bare metallic stent placement in a rat urethral model.

Reduction of Tissue Hyperplasia with a Rhenium188 Mercaptoacetyltriglycine-3–filled Balloon: Preliminary Study in a Canine Urethral Model

To evaluate the efficacy of beta-radiation therapy with rhenium-188 mercaptoacetyltriglycine-3 (MAG(3))-filled balloons to reduce tissue hyperplasia secondary to stent placement in 18 canine urethras. Eight dogs were treated with 188-Re MAG(3)-filled balloon dilation immediately after stent placement and were killed 4 weeks later (group I, n = 4) or 8 weeks later (group II, n = 4). Five dogs were treated with 188-Re MAG(3)-filled balloon dilation 2 weeks after stent placement and were killed 4 weeks after stent placement (group III). The remaining five dogs were treated with conventional balloon dilation immediately after stent placement and were killed 4 weeks later; these animals formed the control group (group IV). Retrograde urethrography (RUG) was performed during follow-up and three histologic parameters were investigated: the number of epithelial layers, papillary projection thickness, and degree of submucosal inflammatory cell infiltration. The areas inside and outside the ends of the stents were evaluated in each case after animal sacrifice. After testing statistical significance of data for RUG and histologic findings in the four study groups, the Mann-Whitney U test was used to compare groups I and II to determine delayed effects of irradiation, groups I and III to determine benefits of delayed irradiation, groups I and IV to determine efficacy of immediate irradiation for reducing tissue hyperplasia, and groups III and IV to determine efficacy of delayed irradiation for reducing tissue hyperplasia. There were no significant differences in the four study groups on RUG before animal sacrifice. Between groups I and II, group II showed significantly lower mean values in five of six histologic comparisons. Between groups I and III, group III showed significantly lower mean values in only papillary projection thickness inside the stent ends. Between groups I and IV, group I showed significantly lower mean values in all three histologic parameters outside the stent ends. Between groups III and IV, group III showed significantly lower mean values in only two histologic parameters (papillary projection thickness in the in-stent area and inflammatory cell infiltration outside the stent edges). beta-Irradiation with use of a 188-Re MAG(3)-filled balloon shows the potential to reduce tissue hyperplasia secondary to stent placement in a canine urethral model. Treatment with 188-Re MAG(3)-filled balloons at the time of stent placement shows not only favorable outcomes for reducing tissue hyperplasia but also improved delayed effects until 8 weeks.

Proliferative lesions in swimbladder of Japanese medaka Oryzias latipes and guppy Poecilia reticulata.

Thirteen cases of proliferative lesions of the swimbladder were encountered in Japanese medaka Oryzias latipes and guppy Poecilia reticulata from about 10,000 medaka and 5000 guppies used in carcinogenicity tests and histologically examined. Two of the 4 cases from medaka and 8 of the 9 from guppies occurred in untreated control specimens. The lesions affected the gas gland epithelium and included hyperplasia, adenoma, and adenocarcinoma. One medaka had hyperplasia of the gas gland epithelium and in 1 guppy the gland was enlarged with an increase in the number of epithelial layers. Gas gland adenomas, 3 cases in medaka and 1 in the guppy, were typically larger than the hyperplastic lesions, formed expansive masses up to 1 mm in greatest dimension, and exhibited a solid or glandular growth pattern and mild cellular pleomorphism. Adenocarcinoma was the most advanced lesion and all 7 cases occurred in guppies. Adenocarcinomas sometimes filled the entire swimbladder and measured up to 2.5 mm in diameter. Cells of adenocarcinomas were highly pleomorphic, with atypical nuclei, and an elevated mitotic activity. Because most of these tumors occurred in fish from control groups or in tests with noncarcinogenic compounds, the lesions observed here are probably spontaneous rather than chemically induced. Their rare occurrence, however, makes swimbladder proliferative lesions in small-fish carcinogenesis models sensitive indicators of compounds that might target cells of the gas gland.

Alterations in rat vaginal histology by exogenous gonadotrophins.

Changes in vaginal epithelium are known to occur during the normal oestrous or menstrual cycle and in ovariectomised animals in response to various hormones. However, vaginal changes due to exogenous gonadotrophins superimposed on the normal hormonal milieu as occurs in in vitro fertilisation programmes have not previously been demonstrated. Female rats were hyperstimulated with follicle stimulating hormone and human chorionic gonadotrophin prior to mating. Control mated animals were not injected. Vaginal tissue was collected at 4.5, 5.5 and 6.5 d after mating. Tissue was processed for light microscopy. Hyperstimulation by the exogenous gonadotrophins caused mucification, a decrease in the number of epithelial layers and an increase in the thickness of the epithelium on d 4.5 of pregnancy. The mitotic index of the epithelial cells was depressed in the hyperstimulated rats with respect to control animals. Exposure to high levels of oestradiol and an altered progesterone:oestradiol ratio appear to have caused the changes in the vaginal epithelium.

Effects of clomiphene citrate on vaginal epithelium of ovariectomised rats.

Scanning electron microscopy and light microscopy have been used to study changes to the vaginal epithelium induced by exogenous hormones and clomiphene citrate (CC) administered to ovariectomised rats. Oestrogen (E2) administration resulted in epithelial cell proliferation and keratinisation. The administration of the E2/anti-E2 CC also resulted in the stimulation of cell proliferation, but not to the extent produced by E2. Lack of keratinisation, a decreased number of epithelial layers and decreased epithelial height were viewed as non-oestrogenic, or retarded oestrogenic, effects of CC. Modifications to the surface of vaginal luminal cells were also apparent following CC treatment. Cell apices were raised and separated by prominent borders; the surface covering consisted of short bulb-tipped microvilli that clumped together to form rosettes. Individual, elongated microvilli were also evident. The results of this study indicate that CC has retarded oestrogenic actions, as well as a unique ability to alter cell and surface morphology to produce characteristics dissimilar to those seen after treatment with E2 and progesterone.

Morphologic changes of the esophageal mucosa in the rat after chronic alcohol ingestion

Fifteen litter-matched pairs of Sprague-Dawley rats were divided into two groups, one fed an alcoholic diet and the other fed an isocaloric but non-alcoholic diet. 5 animals each of the experimental and control groups were sacrificed at 98, 200 and 290 d. The upper part of esophagus was fixed for morphological analysis of semi-fine sections. The following histological observations were made on the oral-esophageal mucosa of the alcohol-consuming animals: An epithelial atrophy was observed between 200 and 290 d of alcoholisation . This atrophy was not the result of a decrease in the number of epithelial layers, but was associated with a decrease in basal cellular size. A basal cell pleomorphism and a tendency towards epithelial dysplasia were the rule after long time alcohol consumption. These observations reflect features resembling to those seen in Plummer- Vinson syndrome, a precancerous state in humans.