Long-term Histological Changes Research Articles

Long-term pulmonary repair in rat lungs after sublobar resection: electrocautery versus stapler methods.

We investigated and compared the long-term (6-month) histologic changes in a rat model of sublobar resection created using electrocautery or stapler techniques. Nine-week-old male rats were anesthetized and intubated; thoracotomy with sublobar resection was performed in the right middle lobe using electrocautery or stapler techniques. Histological examination was performed at 2, 4, 8, 12, and 24weeks post-surgery to assess long-term effects on lung tissue repair and morphologic changes. Lung expansion and alveolar epithelial cell proliferation were evaluated by measuring the mean linear intercept and counting the number of alveolar type I and II cells. The electrocautery group showed signs of lung self-repair at the resected area over time, with inflammatory cell infiltration followed by growth of vessels and bronchioles. Mesothelial cells covered the resected area by 2weeks; elastic fibers gradually connected from both sides by 24weeks. Lung expansion, measured by mean linear intercept, was initially small below the electrocautery resection area at 2weeks but recovered from 4 to 24weeks. The stapler group showed persistently small mean linear intercept over time. In the electrocautery group, the number of alveolar type II cells was higher just below the resection than in other areas from 2 to 24weeks, followed by alveolar type I cells (4 to 24weeks). The stapler group showed a transient alveolar type II cell increase at 2weeks. Compared to the stapler technique, electrocautery mayprovide advantages for postoperative lung repair by promoting lung expansion and alveolar epithelial cell proliferation.

Acute and chronic mammary periprosthetic histological changes of the muscle

Augmentation mammoplasty with subpectoral prosthesis implantation is a frequent performed procedure in plastic surgery for reconstructive and aesthetic purposes. Although prosthesis implantation in a pocket under the major pectoralis muscle has been related to volumetric and functional alterations, there is not much information about the associated short- and long-term histological changes. Therefore, the aim of our study was to describe the acute and chronic histological muscle alterations associated with subpectoral prosthesis implantation. We collected samples from patients with breast tissue expander (<6 months after implantation) and prosthesis (>1 year after implantation) and from patients without implantation as a control group. The samples were processed for assessing their histological, histochemical and immunohistochemical properties. In the control group, no relevant histological findings were identified. Additionally, in the patients with expander, we observed mild augmentation of the internalised nuclei, normal morphology, significant muscle atrophy and fibrosis, whereas in the patients with prosthesis considerable augmentation of internalised nuclei, significant muscle atrophy, fibrosis and alteration of normal muscle morphology were observed. Prosthesis implantation induces histological changes in the periprosthetic striated muscle. Chronic fibrosis and inflammation play key roles in this process, which should be characterised in more detail from the histological and molecular biological perspective.

The Role of Sensory Nerves in Dental Pulp Homeostasis: Histological Changes and Cellular Consequences after Sensory Denervation.

Homeostatic maintenance is essential for pulp function. Disrupting pulp homeostasis may lead to pulp degeneration, such as fibrosis and calcifications. Sensory nerves constitute a crucial component of the dental pulp. However, the precise involvement of sensory nerves in pulp homeostasis remains uncertain. In this study, we observed the short-term and long-term histological changes in the dental pulp after inferior alveolar nerve transection. Additionally, we cultured primary dental pulp cells (DPCs) from the innervated and denervated groups and compared indicators of cellular senescence and cellular function. The results revealed that pulp fibrosis occurred at 2 w after the operation. Furthermore, the pulp area, as well as the height and width of the pulp cavity, showed accelerated reductions after sensory denervation. Notably, the pulp area at 16 w after the operation was comparable to that of 56 w old rats. Sensory denervation induced excessive extracellular matrix (ECM) deposition and increased predisposition to mineralization. Furthermore, sensory denervation promoted the senescence of DPCs. Denervated DPCs exhibited decelerated cell proliferation, arrest in the G2/M phase of the cell cycle, imbalance in the synthesis and degradation of ECM, and enhanced mineralization. These findings indicate that sensory nerves play an essential role in pulp homeostasis maintenance and dental pulp cell fate decisions, which may provide novel insights into the prevention of pulp degeneration.

MP03-06 VAGINAL DELIVERY ALTERS THE MUSCLE FIBER COMPOSITION OF THE PELVIC FLOOR MUSCLES

You have accessJournal of UrologyCME1 Apr 2023MP03-06 VAGINAL DELIVERY ALTERS THE MUSCLE FIBER COMPOSITION OF THE PELVIC FLOOR MUSCLES Takeya Kitta, Yui Abe-Takahashi, Mifuka Ouchi, Hiroki Chiba, Madoka Hoguchi, Mio Togo, Naohisa Kusakabe, Hidehiro Kakizaki, and Nobuo Shinohara Takeya KittaTakeya Kitta More articles by this author , Yui Abe-TakahashiYui Abe-Takahashi More articles by this author , Mifuka OuchiMifuka Ouchi More articles by this author , Hiroki ChibaHiroki Chiba More articles by this author , Madoka HoguchiMadoka Hoguchi More articles by this author , Mio TogoMio Togo More articles by this author , Naohisa KusakabeNaohisa Kusakabe More articles by this author , Hidehiro KakizakiHidehiro Kakizaki More articles by this author , and Nobuo ShinoharaNobuo Shinohara More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003214.06AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: It is well known that transvaginal childbirth weakens the pelvic floor muscles (PFM) and pelvic nerves, leading to stress urinary incontinence (SUI). PFM training is recommended as Grade A conservative therapy for SUI. Thus, PFM play important roles in lower urinary tract functions. In our previous study, we reported that the distribution of fiber types in the PFM is altered beginning 1 to 4 weeks post vaginal distension (VD), leading to muscle atrophy. SUI after vaginal delivery is known to persist in approximately 2% of patients who have had a vaginal delivery, even after 2 months postpartum. Therefore, we hypothesized that the long-term SUI that occurs after vaginal delivery may be influenced by the fiber-type distribution of PFM. The purpose of this study was to examine the long-term histological changes in PFM in a rat model of VD. METHODS: Eighteen female Sprague-Dawley rats (248-335 g) were used in this study. They were divided into 3 groups: a sham group, 1 (1M) and 3 months (3M) post VD. Urethral pressure was measured as urethral baseline pressure (UBP) and amplitude of urethral response (A-URE) (cmH2O). Right side pubococcygeus muscle (Pcm) was sampled and wet weight to body weight was measured. Pcm frozen sections 10 mm thick were prepared and stained using succinate dehydrogenase (SDH) activity. Stained images were imported into a personal computer to identify muscle fiber type (Ⅰ, Ⅱa and Ⅱb) distribution. In addition, the cross-sectional area (CSA) (μm2) of each muscle fiber type was determined. One-way analysis of variance was performed to compare the data among 3 groups. P value of less than 0.05 was regarded to be statistically significant. The present study was conducted after being approved by Animal Study Facility Ethics Committee. RESULTS: UBP was not significantly different among the 3 groups. In A-URE, 1M group was significantly lower than in the sham (p < 0.05). The Pcm wet weight was significantly lower in the 1M and 3M groups compared to the sham group (p<0.05). The CSA of type Ⅰ fibers in the Pcm was significantly lower in the 1M group than in the 3M group (p<0.05). The CSA of Type Ⅱa and Ⅱb fibers was not significantly different among the 3 groups. The ratio of typeⅠ fibers was significantly lower in the 1M and 3M groups compared to the sham group. The ratio of type Ⅱa fibers was not significantly different among the 3 groups. The ratio of type Ⅱb fibers was significantly higher in the 1M and 3M groups than in the sham group (p<0.05). CONCLUSIONS: In the present study, at 3 months post VD, the urethral function improved, but there was a decrease in muscle wet weight of the Pcm and a change in muscle fiber composition (leading to a decrease in slow-twitch muscle response). This may be due to decreased muscle function due to atrophy of the PFM and changes in muscle composition when SUI occurs beyond 3 months after vaginal delivery. Source of Funding: none © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e23 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Takeya Kitta More articles by this author Yui Abe-Takahashi More articles by this author Mifuka Ouchi More articles by this author Hiroki Chiba More articles by this author Madoka Hoguchi More articles by this author Mio Togo More articles by this author Naohisa Kusakabe More articles by this author Hidehiro Kakizaki More articles by this author Nobuo Shinohara More articles by this author Expand All Advertisement PDF downloadLoading ...

Sliced vs crushed cartilage for camouflage: long-term graft survival and histological outcomes.

In this study, we proposed a "sliced-partial thickness cartilage graft" for nasal contour restoration purposes and compared the long-term graft survival and histological changes of sliced, crushed, and intact cartilage grafts. Nasal septal and auricular cartilage grafts were harvested from 8 rabbits. Sliced, crushed, or intact cartilage grafts were measured in thickness with a micrometer and re-implanted. 4months later, specimens were histologically evaluated and thickness were measured. Both nasal septal and auricular crushed cartilage lost significantly more chondrocytes than sliced samples together with fibrosis, multiple fracture lines, and even ossification. Sliced and intact cartilages were histologically similar except sliced cartilage had some minor changes limited to its cut surface. Sliced cartilages retained their thickness, histology, and structural properties in the long term similar to intact cartilages whereas -contrary to expectations- crushed specimens had significantly higher thickness measurements at the end of 4months. Sliced cartilage grafts prepared with an atraumatic cartilage slicer are an ideal camouflaging material with its uniform thickness, and malleability. Crushed cartilages seemingly getting thicker without histological findings could be explained by lower than actual initial measurements due to its structural weakness and getting squeezed when the standard pressure of the micrometer was applied.

Comparison of different energy response for lipolysis using a 1,060-nm laser: An animal study of three pigs.

Non-invasive body-sculpting procedures are becoming increasingly popular. The application of 1,060nm of laser energy transcutaneously to hyperthermically induce the disruption of fat cells in the abdomen is a type of non-invasive procedure. The purpose of this study was to compare the treatment results from two parameters of the same system, each with different energy output levels, in an in vivo porcine model to determine the most effective application. Female pigs (n=3) were used in this study. We examined the effects of the treatment using photography, ultrasonography, gross and microscopic pathology, and histological examination in order to determine the mechanism of action, efficacy, and safety of the procedure. Blood chemistry analysis was performed before each session to check lipid levels and to monitor for any adverse changes in markers that may indicate liver damage. Biopsies were taken and routinely processed with hematoxylin and eosin and Oil Red O stains to examine for tissue damage at baseline and after each treatment. Terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling (TUNEL) assays were performed to check for apoptotic-related DNA damage. Ultrasonic imaging of the same area before and after the application of 1,060nm of laser energy at outputs of 0.9 and 1.4W/cm2 showed that the density of the fat layer changed immediately after irradiation due to the transient heat transfer in the fat layer. Preclinical evaluation was performed to obtain comparison data on the safety and efficacy of subcutaneous fat reduction after applying the different energy outputs of 0.9 and 1.4W/cm2 . Based on our findings, we suggest that long-term histologic changes through the use of these devices suggest a comparative effectiveness of the treatment energy.

Short- and Long-term Histological Changes in Liver Parenchyma After Different Resection Methods and Their Potential Role in Treatment of Colorectal Liver Metastasis.

Optimal surgical margins, parenchymal-sparing technique and the effect of the surgical devices on the liver resection surface are currently hot topics. The aim of this study was to set up a surviving animal model to detect histological changes on the resection surface induced by the resection method and the thermal effect of monopolar electrocautery in 'spray mode'. Eighteen male Wistar rats were used; all rats were subjected to standardized liver resection and resection surface coagulation. Resection surface samples were collected immediately after the operation from the first group, and at 1 week and 3 weeks after the operation from the second and third groups, respectively. The samples were histologically investigated. Spray diathermy was shown to cause parenchymaI destruction of varying depth on the resection surface due to immediate coagulation and consequent necrosis. Spray diathermy on the resection surface can also destroy the area that contains possible tumor cells after R1 resection and increases the tumor clearance without worse survival outcomes.

Long-term histological change in chronic hepatitis C patients who had received peginterferon plus ribavirin therapy with sustained virological response

The improvement in liver histology is an important aim in the management of hepatitis C virus (HCV) infection. Previous studies suggest that antiviral treatment could reduce the progression of hepatic fibrosis, especially in patients with sustained virological response (SVR). However, most studies were limited by short-term evaluations and the liver stiffness was assessed by non-invasive methods. In our study, we performed a paired liver biopsy study aimed at analyzing the long-term histological changes in patients with SVR. We included 31 patients who had been previously treated with peginterferon plus ribavirin. All patients achieved SVR and had received pre- and post-treatment liver biopsies. The histological appearance of fibrosis and inflammation were assessed with METAVIR scoring system and Histological Activity Index (HAI) criteria. We analyzed several factors associated with the histological response. The median interval between two biopsies was 93.0 months. The percentage of patients with fibrosis regression, stable, and progression were 19%, 45%, and 36%. A total of 71% of patients achieved inflammation improvement, whereas 6% and 23% of patients had stable disease and disease-progression, respectively. We showed that the patients without baseline advanced fibrosis and those having a lower baseline HAI score had higher risk of fibrosis worsening. Baseline fibrosis and necroinflammation status did not influence HAI change significantly. The progression of hepatic fibrosis and inflammation can be reversed in some patients who had long-term virological suppression. Patients with advanced baseline fibrosis and higher inflammatory stages seemed to receive more histologic benefit from successful antiviral treatments.

Hepatic lipidosis in high-yielding dairy cows during the transition period: haematochemical and histopathological findings

The aim of this study was to assess the severity and distribution of hepatic lipidosis in high-yielding dairy cows during the transition period by the evaluation of body condition score (BCS), serum levels of non-esterified fatty acids (NEFA) and β-hydroxybutyrate (BHB) and histological liver lipid content (GdL). Twenty-seven dairy cows, with a milk production of ~10 000 kg per year were enrolled in an experiment. Clinical examination was performed to evaluate the health status or the presence of periparturient diseases after calving. Animals were divided into two groups: healthy (HG; n = 11) and sick (SG; n = 16). The evaluation of BCS, NEFA, BHB and liver biopsies were performed at 15 ± 5 days prepartum (T0), 10 ± 2 days postpartum (T1), 30 ± 2 days postpartum (T2) and 50 ± 2 days postpartum (T3). Two-way repeated-measure ANOVA was applied to assess statistical significance of sampling time and between groups for all variables. Pearson’s correlation coefficient was used to investigate the relationship between all variables. Results showed BCS loss from T0 to T3 in SG and a significant increase of NEFA and BHB at T1. The GdL began to be mild at T0 increasing and becoming moderate to severe at T1, fairly regressing, but not disappearing, at T2 and T3, in both groups. This study showed that high lipomobilisation with a mild to moderate fat infiltration does not imply that ketosis or other periparturient diseases might be present. Our results suggest that hepatic lipidosis is associated with long-term histological and metabolic changes in dairy cows.

The natural history of anal transition zone inflammation and possible relationship to pouchitis: a long-term longitudinal study

Reservoir ileitis (pouchitis) is the most common complication after pelvic pouch surgery for ulcerative colitis and the aetiology remains largely unknown. The anal transition zone (ATZ) contains the only remaining colonic epithelium after ileal pouch anal anastomosis (IPAA) and may provide important clues as to whether ulcerative colitis and pouchitis share a common pathogenesis. The aim of this study was to evaluate longitudinally the long-term histological changes in the ATZ and their relationship to the incidence of pouchitis. Patients with a double-stapled IPAA for ulcerative colitis at an academic medical centre with at least 10years of clinical and histological follow-up were identified from a prospective database. Annual ATZ and pouch biopsies were taken and interpreted by two expert gastrointestinal pathologists. ATZ histological variability score, the incidence of pouchitis, and function were correlated over time. ATZ biopsies were scored from one to three based on the extent of inflammation. Sixteen of the 114 patients having IPAA fulfilled the criteria for admission to the study. There were 179 biopsies of the ATZ. All exhibited variability in ATZ histology over time and 81% had a 2-unit change in their inflammatory score. There was no correlation between pouchitis and histological severity score of the ATZ. Similarly, function over time did not vary with the intensity of ATZ inflammation. ATZ inflammation varies substantially over time in most patients. But these changes from year to year did not correlate with function or the occurrence of pouchitis.

Long-Term Histologic Changes and Effects of Perichondrium Preservation of Auricular Cartilage Grafted in Rabbit Tympanic Bullae

Introduction: This study evaluated the long-term histologic changes of grafted auricular cartilage in rabbit tympanic bullae. Materials and Methods: Auricular cartilage with or without perichondrium was prepared and cut into small pieces to obliterate the rabbit tympanic bullae. The histologic changes of the grafted cartilage in both groups were compared 20 months after surgery. Results: Remarkable spongy bony trabeculae of mature lamellar bone with red bone marrow formation were observed in the perichondrium-preserved group. Parts of the grafted cartilage pieces were invaded and replaced by bone and bone marrow. The grafted cartilage pieces grossly maintained their original polygonal shapes, and no osteochondral tissue regeneration was observed in the perichondrium-removed group. The viable chondrocyte ratios were 46.21 ± 5.58 versus 27.80 ± 4.81%, and the minimal resorption ratios were 10.31 ± 3.27 versus 2.98 ± 1.48% in the perichondrium-preserved (n = 14) and -removed groups (n = 12, p < 0.05). The tissue ratios were cartilage: 38.18 ± 8.76 versus 52.97 ± 9.30%; lamellar bone: 18.49 ± 5.31 versus 0.82 ± 0.43%; bone marrow: 20.72 ± 6.27 versus 0.00 ± 0.00%; fibrous tissue: 10.13 ± 2.74 versus 5.81 ± 2.20%, and adipose tissue: 12.01 ± 4.48 versus 40.70 ± 7.83% in the perichondrium-preserved and -removed groups. The differences were all statistically significant (p < 0.05). Conclusion: A space-filling mass effect with minimal resorption of the cartilage pieces was observed in the perichondrium-removed group. In addition to this mass effect, the progenitor cells in the preserved perichondrium allowed active bone tissue regeneration and cartilage resorption in the perichondrium-preserved group.

Long-Term Histologic Changes in Nasal Mucosa after Total Laryngectomy

Objective. To determine the long-term histopathologic changes in nasal mucosa and the relationship between progression of the histopathologic changes and the duration without air current stimulation. Material and Method. Biopsies were taken from the inferior turbinates of 11 laryngeal cancer patients after total laryngectomy. Specimens were stained with hematoksilen-eosin and several histopathologic parameters were examined under light microscopy. Results. All of the patients demonstrated at least one histopathologic abnormality (100%, n = 11). Goblet destruction and stromal fibrosis were the most common findings (81%, n = 9), followed by focal epithelial atrophy and subepithelial seromusinous gland destruction (45%, n = 5), neovascularization and congestion (36%, n = 4), complete epithelial atrophy and mixoid degeneration (27%, n = 3). According to the duration between laryngectomy and biopsy, patients were grouped in to three: group 1; less than 12 months (36%, n = 4), group 2; 12–36 months (18%, n = 2), and group 3; more than 36 months (45%, n = 5). Only congestion was found to be decreased as the duration increased (P < .005). Conclusion. In laryngeal cancer patients histopathologic changes occur in nasal mucosa eventuate due to the cessation of air current stimulation, however there was no relation between progression of the histopathologic findings and the duration of cessation.

Long-Term Histologic Changes in Nasal Mucosa after Total Laryngectomy

This recently published interesting paper [1] showed statistically significant reduction (P < .005) in congestion of inferior turbinate mucosa in 2 groups of post-total laryngectomy patients over a period of time (group 1; less than 12 months, group 2; 12–36 months). I am intrigued as to which statistical test was used to calculate this and the other P values, since it was not mentioned in the study. Also, I wonder what the authors' and readers' opinions are with regards to the time intervals at which biopsies were taken postoperatively. Could the other histological indices have born a statistically significant difference between the groups, where shorter time intervals are to be used (e.g., 3, 6, and 9 months)? The references cited by the authors themselves certainly do not seem to observe any standard established time frames. It would be interesting to gauge readers' opinion on these matters.

Histopathological Changes Associated With Dextranomer/Hyaluronic Acid Injection for Pediatric Vesicoureteral Reflux

Few studies have examined the medium and long-term histological changes associated with periureteral injection of dextranomer/hyaluronic acid copolymer (Deflux(R)). We present the results of a histological review of a series of distal ureteral excisions in patients undergoing ureteroneocystostomy after failed dextranomer/hyaluronic acid injection. All patients undergoing ureteroneocystostomy after failed dextranomer/hyaluronic acid injection(s) at 1 institution were eligible for this study. Excised ureteral segments were histologically examined by a single urological pathologist. An immunohistochemical battery was used for each specimen, including hematoxylin and eosin, CD3, CD20, MIB-1 and trichrome stains. Pathological criteria included the presence, location and intensity of fibrosis, giant cell reaction, chronic inflammation, free dextranomer/hyaluronic acid, and CD3, CD20 and MIB-1 staining. Pathological features were correlated with the time from injection to surgical excision. The ureters of 16 children with a mean age of 4.5 years were examined. Median time from injection to implant excision was 8 months. Giant cell reaction was present in 94% of patients and it was typically located in the serosa. No histological or immunophenotypical feature correlated with the duration of implantation except CD3+ and CD20+ lymphocyte counts, which increased with time from injection (p = 0.06 and 0.02, respectively). Dextranomer/hyaluronic acid appears to be stable and safe for use after 3 to 22 months of followup of subureteral injection. The periureteral inflammatory reaction increases with time, although no increases in nuclear turnover or fibrosis were detected.

Histologic findings after gastrocystoplasty in rabbits

Purpose The aim of this study was to investigate the long-term histologic changes after bladder augmentation with gastric segment in an animal subject. Materials and Methods Gastrocystoplasty was performed in 13 young, 3-month-old male rabbits. Open biopsies were taken from the native bladder and the gastric segment preoperatively and at 3, 6, and 12 months postoperatively. Sections were examined with H&E and periodic acid–Schiff (PAS) staining. Indirect immune peroxidase method was additionally applied to detect the carcinoembrionic antigen, the proliferative activity, and the gene for the tumor protein p53 in the epithelium. Results On the native bladder, at the 3-month follow-up, polyps, mucosal edema, submucosal fibrosis, and squamous cell metaplasia were detected, which did not change during the follow-up. On the gastric segment, at the 3-month follow-up, parietal cell hyperplasia and inflammatory mucosal overgrowth were detected; at the 6-month follow-up, inflammation or atrophy of the gastric mucosa and colonic-type metaplasia was found. These alterations remained unchanged during later course of follow-up. Neither dysplasia nor malignancy was observed during the 12-month follow-up. Conclusions The present study supports the clinical observations of low cancer risk after gastrocystoplasty and may indicate different effect of gastric secretion on uroepithelium and that of urine on gastric mucosa.

Mesenchymal cells infiltrating a bladder acellular matrix gradually lose smooth muscle characteristics in intraperitoneally regenerated urothelial lining tissue in rats

To characterize serial long-term histological changes in mesenchymal cells infiltrating a collagen-based matrix, as in a hollow organ with differentiated urothelial lining created intraperitoneally by grafting cultured urothelial cells, mesenchymal cells with smooth-muscle immunohistochemical characteristics infiltrated into the scaffold, despite no mesenchymal cells being seeded into the scaffold before grafting. To regenerate a urothelial lining tissue intraperitoneally, rat urothelial cells were cultured and seeded with the feeder-layer technique onto bladder acellular matrix (BAM). After 7 days of cultivation to attach urothelial cells on the BAM, the matrix was folded with the urothelial cells inside and grafted onto the mesentery of the previously partially cystectomized rat. The grafted urothelial cells on the BAM, which formed a monolayer before grafting, stratified into three to four layers as early as 4 days after grafting. Although the regenerated urothelium became thinner with time, there was urothelial stratification and a peculiar angular appearance on the apical surface of the regenerated urothelium even after 56 days. The mesenchymal cells infiltrating the BAM showed positive immunohistochemical staining to alpha-smooth muscle actin or desmin at 7 days. Subsequently, the number of actin- or desmin-positive cells gradually decreased with time. On transmission electron microscopy, the infiltrating mesenchymal cells were characterized as myofibroblasts at 7 days. Smooth muscle-like cells were identified at 14 and 28 days, and fibrocytes were the main population at 56 days. Although epithelial-mesenchymal interactions have been assumed to be one of the most critical factors in smooth-muscle development, mesenchymal cells infiltrating the scaffold in this intraperitoneal regeneration model gradually lost smooth muscle characteristics with time. These results suggest that interactions between cultured urothelial cells and infiltrating mesenchymal cells alone could not maintain the smooth muscle character of infiltrating mesenchymal cells.

Long-term alteration in the air-infused rabbit retina

To investigate the long-term histological changes in rabbit retina damaged by infusion air during vitrectomy. Fourteen eyes of 14 rabbits were used. A standard three-port vitrectomy with artificial posterior vitreous detachment followed by fluid-air exchange was performed. After the fluid-air exchange, one side port was kept open for 30 s to freely introduce the air into the vitreous cavity under a pressure of 40 mmHg. Four weeks after surgery, indocyanine green angiography and histological examination were performed. At the air-infused area, indocyanine green angiography revealed the filling delay of the choroidal circulation in the early phase. The retinal surface was smooth and the internal limiting membrane was revealed to be intact by scanning electron microscopy. Light microscopy documented the thinning of the photoreceptor layer in the air-infused area. Transmission electron microscopy showed the disarrangement of the retinal pigment epithelium and loss of choriocapillaries. Infusion air during vitrectomy causes long-term outer retinal damage after surgery. Thinning of the photoreceptor cells, disarrangement of the retinal pigment epithelium and loss of choriocapillaries reflect the findings that we have observed previously in clinical cases. Visual field defect is a complication of vitreous surgery using fluid-air exchange. Although the visual field defects were observed just after surgery, abnormal fundus lesions continued to appear over time after the surgical procedure.

Histological analysis of silicone breast implant capsules and correlation with capsular contracture

Background: A study was undertaken to investigate long-term histological changes in the environment of breast implants and their correlation with complains at the time of capsular contracture defined by the Baker score. Method: The collagenous capsules of 53 silicone breast implants from 43 patients (23 smooth and 30 textured devices) were evaluated histologically for capsular thickness, the presence of histiocytes, the amount of silicone and calcification in the capsule, and the presence of synovial-like metaplasia of the inner surface of the capsule with light microscopy and polarised light. All parameters were correlated with the Baker score. Results: A significantly higher degree of the Baker score was found with increasing patient age ( p<0.001), implant duration ( p<0.02), and capsular thickness ( p<0.009). A trend towards greater capsular thickness was documented in patients who had a breast augmentation for cosmetic reasons. Synovial-like metaplasia was seen in 28 capsules (52.8%). The highest incidence was found in textured implants with a duration of less than 5 years. Histiocytic inflammation was more common in patients with clinical symptoms ( p<0.001) and around subglandular implants ( p<0.096). Conclusions: The histological findings of breast capsules were related to: the nature of the device surface (smooth versus textured), implant duration, and the degree of capsular contracture. Capsular contracture (Baker score of 3 or 4) was related to implant duration, capsule thickness, patient age, and inflammation.

Late arterial responses (6 and 12 months) after (32)P beta-emitting stent placement: sustained intimal suppression with incomplete healing.

Three-month studies of stent-delivered brachytherapy in the rabbit model show reduced neointimal growth. However, intimal healing is delayed, raising the possibility that intimal inhibition is merely delayed rather than prevented. The purpose of this study was to explore the long-term histological changes after placement of beta-emitting radioactive stents in normal rabbit iliac arteries. Three-millimeter beta-emitting (32)P stents (6, 24, and 48 microCi) were placed in normal rabbit iliac arteries with nonradioactive stents as controls. Animals were euthanatized at 6 and 12 months, and histological assessment, morphometry, and analysis of endothelialization were performed. Morphometric measurements demonstrated a >50% reduction in intimal growth and percent lumen stenosis within 24- and 48-microCi stents versus control nonradioactive stents at both 6 and 12 months. However, the 24- and 48-microCi stents also showed delayed healing of the intimal surface, characterized by persistent fibrin thrombus with nonconfluent areas of matrix, incomplete endothelialization, and increased intimal cellular proliferation. Stent edge stenosis was present at 12 months in the 24- and 48-microCi stent groups, characterized by both intimal thickening and negative arterial remodeling. Inhibition of intimal growth is maintained 6 and 12 months after (32)P beta-emitting stent placement. However, delayed arterial healing, incomplete endothelialization, and edge effects are present.

Long-term histologic effects of inferior turbinate laser surgery.

In this study we sought to define the histologic changes produced by laser treatment of inferior turbinates. Eight inferior turbinates with prior laser treatment (mean, 26.8 months) were analyzed by light microscopy after turbinectomy for relief of refractory nasal obstruction. Histologic findings were compared with those of a group of 8 hypertrophic inferior turbinates that had no previous laser surgery. Laser-treated areas of the inferior turbinates demonstrated a histologically bland appearance, with marked diminution of seromucinous glands and relative preponderance of connective tissue matrix. Prominence of venous sinusoids was also significantly reduced in the laser-treated areas. Surface epithelium including goblet cells was reconstituted over the areas of laser application. Clinical laser surgery of the inferior turbinate produces striking long-term histologic changes. The data suggest a differential response of turbinate histologic components to application of laser energy, with the glandular component being particularly sensitive. Further correlative study is needed to clarify the clinical significance of laser-induced histologic changes in inferior turbinates.