Luminal Opening Research Articles

Timing of silicone stent removal in patients with post-tuberculosis bronchial stenosis

CONTEXT:In patients with post-tuberculosis bronchial stenosis (PTBS), the severity of bronchial stenosis affects the restenosis rate after the silicone stent is removed. In PTBS patients with incomplete bronchial obstruction, who had a favorable prognosis, the timing of stent removal to ensure airway patency is not clear.AIMS:We evaluated the time for silicone stent removal in patients with incomplete PTBS.SETTINGS AND DESIGN:A retrospective study examined PTBS patients who underwent stenting and removal of a silicone stent.METHODS:Incomplete bronchial stenosis was defined as PTBS other than total bronchial obstruction, which had a luminal opening at the stenotic segment on bronchoscopic intervention. The duration of stenting was defined as the interval from stent insertion to removal. The study included 44 PTBS patients and the patients were grouped at intervals of 6 months according to the duration of stenting.RESULTS:Patients stented for more than 12 months had a significantly lower restenosis rate than those stented for less than 12 months (4% vs. 35%, P = 0.009). Multiple logistic regression revealed an association between stenting for more than 12 months and a low restenosis rate (odds ratio 12.095; 95% confidence interval 1.097-133.377). Moreover, no restenosis was observed in PTBS patients when the stent was placed more than 14 months previously.CONCLUSIONS:In patients with incomplete PTBS, stent placement for longer than 12 months reduced restenosis after stent removal.

Electron Microscopic Analysis of a Spherical Mitochondrial Structure

Mitochondria undergo dynamic structural alterations to meet changing needs and to maintain homeostasis. We report here a novel mitochondrial structure. Conventional transmission electron microscopic examination of murine embryonic fibroblasts treated with carbonyl cyanide m-chlorophenylhydrazone (CCCP), a mitochondrial uncoupler, found that more than half of the mitochondria presented a ring-shaped or C-shaped morphology. Many of these mitochondria seemed to have engulfed various cytosolic components. Serial sections through individual mitochondria indicated that they formed a ball-like structure with an internal lumen surrounded by the membranes and containing cytosolic materials. Notably, the lumen was connected to the external cytoplasm through a small opening. Electron tomographic reconstruction of the mitochondrial spheroids demonstrated the membrane topology and confirmed the vesicular configuration of this mitochondrial structure. The outside periphery and the lumen were defined by the outer membranes, which were lined with the inner membranes. Matrix and cristae were retained but distributed unevenly with less being kept near the luminal opening. Mitochondrial spheroids seem to form in response to oxidative mitochondrial damage independently of mitophagy. The structural features of the mitochondrial spheroids thus represent a novel mitochondrial dynamics.

The efficacy of bronchoscopic intratumoral chemotherapy in palliation of inoperable lung cancer.

e17556 Background: Endobronchial obstruction is a common complication of advanced-stage lung cancer. Patients presenting with severe bronchial obstruction are at a high risk for developing haemoptysis, post-obstructive pneumonia, or respiratory failure, this often leads to death in weeks to months.Tumor debulking and airway re-canalization has a considerable role in increasing survival in patients with inoperable non-small cell lung cancer (NSCLC). Bronchoscopic endobronchial intratumoral chemotherapy (EITC) is a new intervention to treat airway obstruction. This work aims to determine the efficacy of EITC in palliative care for patients with inoperable NSCLC. Methods: Between April 2009 and June 2011, patients with newly diagnosed non metastatic inoperable symptomatic non-life threatening airway obstruction secondary to NSCLC were selected for tumor debulking via EITC through flexible bronchoscopy. EITC of maximum 20mL cisplatin with the concentration of 50 mg/50 mL was injected into the tumor bulk through flexible needle (weekly for 4 sessions). Patients were followed according to the symptoms, performance and functional status and endobronchial lesions changes after EITC. Results: Forteen male and 1 female were studied in which 7 cases had squamous cell carcinoma, 5 cases had adenocarcinoma and 3 cases had unspecified NSCLC. After 4 sessions of EITC, the involved lumen was considerably opened (> 25%) in 80% of cases in which 7 cases >50% and 5 cases showed a 25–50% luminal opening. Significant improvement was found in dyspnea score, Karnofsky performance scale as well as spirometric and arterial blood gases indices after than before the 4 sessions of EITC. Conclusions: EITC was well tolerated by most of the patients with minimal non systemic complications. In conclusion, EITC is a promising, safe, effective and less invasive procedure for palliative treatment of obstructive non-life threatening endobronchial NSCLC lesions.

P-type ATPases at a glance

P-type ATPases are a large family of integral membrane transporters that are of vital importance in all kingdoms of life. In eponymous distinction from the other main classes of transport ATPase – the FF1 (F-), the vacuolar (V-) and the ATP-binding cassette (ABC-) type – the P-type ATPases form

Morphometric digital measurement of the luminal opening area of colonic crypts (pits) can differentiate the adenomas from other colonic lesions

Differential diagnosis of hyperplastic vs adenomatous lesions is of crucial importance on the daily practice of colonoscopy. This study aimed at quantifying digital morphometric characteristics of colonoscopic images obtained with magnification and chromoscopy of three different types of colonic lesions: hyperplastic, adenomas and carcinomas, and the normal mucosa surrounding the lesions. A total of 2,177 consecutive colonoscopies were analyzed and 105 images were chosen for analysis, divided into 37 hyperplastic lesions, 42 adenomas and 26 carcinomas. Specific digital morphometry was used, to measure the diameter and area of the pits from hyperplastic lesions, adenomatous and carcinomatous lesions, always comparing them with the normal mucosa surrounding pits. Different morphometric measures were performed via image analysis software to measure the mean pit opening diameters and their respective area. The mean pit opening diameters and corresponding area measurements were statistically significant for all groups of lesions examined. The morphometric characteristics of colonoscopy images allowing the observer to compare differences between hyperplastic and adenomatous polyps and colorectal carcinoma lesions. Digital morphometric studies are feasible like the present study shows. This can help the colonoscopist in clinical decisions. A software with morphometric measures can apply and will permit the digital morphometric analysis. The data generated from the application of software, can provide valuable points in differentiation of various lesions, guiding the conduct clinical, already during the endoscopic procedure. Morphometric analysis is more an instance of decision to the colonoscopist and it has important value not for being subjective, but for being objective, since it generates digits of its measures. In these aspects, and among different characteristics, the measure of the area showed to be the most important measure in the differential aspect. Different lesions have different patterns of morphometric measures and theses patterns can be obtained from the study of the characteristics in databases. The endoscopic removal of adenomatous polyps (polypectomy), or a more detailed study of the neoplastic lesions for helping the decision if endoscopic removal (mucosectomy) or surgical resection, and a conservative position in hyperplastic lesions, are proceedings that morphometrics, with another parameters, can help to decide.

Electroporation-mediated transfer of plasmid DNA encoding IL-10 attenuates orthotopic tracheal allograft stenosis in rats

Background Electroporation has been shown to increase the efficacy of intramuscular injection of plasmid DNA, resulting in a higher level of foreign gene expression. Using this technique, we examined the effect of viral IL-10 gene transfer on the prevention of tracheal allograft stenosis in an animal model. Methods On the day of tracheal transplantation, recipient Lewis rats were intramuscularly injected with either plasmid pCAGGS-LacZ or plasmid pCAGGS-viral IL-10, followed immediately by electroporation. Tracheas from Brown Norway donors were transplanted into the backs of Lewis recipients, and the histology of the grafts were assessed 2 and 4 weeks after transplantation. Results The serum level of IL-10 peaked at 2000 pg/ml one day after injection; the level then slowly decreased, but was maintained above 1000 pg/ml until 8 days after injection. At Day 28, the airway lumina of the tracheal allografts were almost completely obliterated by fibroproliferative tissue in the control pCAGGS-LacZ-treated rats. In rats injected once with pCAGGS-viral IL-10, luminal obliteration was significantly decreased compared with the control pCAGGS-LacZ-treated rats (mean luminal opening 46.8% vs 0% p < 0.05). The loss of epithelial cells lining the airway was also decreased in the IL-10-treated group (mean epithelial coverage 42% vs 5% p < 0.05). Multiple injections with pCAGGS-viral IL-10 did not further improve the histological changes. Conclusion IL-10 gene transfer by intramuscular injection using electroporation attenuated tracheal allograft stenosis associated with mild epithelial injury.

Effects of Inhibitors on Luminal Opening of Ca2+ Binding Sites in an E2P-like Complex of Sarcoplasmic Reticulum Ca22+-ATPase with Be22+-fluoride

We document here the intrinsic fluorescence and 45Ca2+ binding properties of putative "E2P-related" complexes of Ca2+-free ATPase with fluoride, formed in the presence of magnesium, aluminum, or beryllium. Intrinsic fluorescence measurements suggest that in the absence of inhibitors, the ATPase complex with beryllium fluoride (but not those with magnesium or aluminum fluoride) does constitute an appropriate analog of the "ADP-insensitive" phosphorylated form of Ca2+-ATPase, the so-called "E2P" state. 45Ca2+ binding measurements, performed in the presence of 100 mm KCl, 5 mm Mg2+, and 20% Me2SO at pH 8, demonstrate that this ATPase complex with beryllium fluoride (but again not those with magnesium or aluminum fluoride) has its Ca2+ binding sites accessible for rapid, low affinity (submillimolar) binding of Ca2+ from the luminal side of SR. In addition, we specifically demonstrate that in this E2P-like form of ATPase, the presence of thapsigargin, 2,5-di-tert-butyl-1,4-dihydroxybenzene, or cyclopiazonic acid prevents 45Ca2+ binding (i.e. presumably prevents opening of the 45Ca2+ binding sites on the SR luminal side). Since crystals of E2P-related forms of ATPase have up to now been described in the presence of thapsigargin only, these results suggest that crystallizing an inhibitor-free E2P-like form of ATPase (like its complex with beryllium fluoride) would be highly desirable, to unambiguously confirm previous predictions about the exit pathway from the ATPase transmembrane Ca2+ binding sites to the SR luminal medium.

Time-dependent viscoelastic properties along rat small intestine

To measure the time-dependent (viscoelastic) behavior in the change of the small intestinal opening angle and to test how well the behavior could be described by the Kelvin model for a standard linear solid. Segments from the duodenum, jejunum, and ileum were harvested from 10 female Wistar rats and the luminal diameter, wall thickness, and opening angle over time (theta(t)) were measured from rings cut from these segments. Morphometric variations were found along the small intestine with an increase in luminal area and a decrease in wall thickness from the duodenum to the ileum. The opening angle obtained after 60 min was highest in the duodenum (220.8+/-12.9 degrees) and decreased along the length of the intestine to 143.9+/-8.9 degrees in the jejunum and 151.4+/-9.4 degrees in the ileum. The change of opening angle as a function of time, fitted well to the Kelvin model using the equation theta(t)/theta(o) = [-eta exp (-lambda t)] after the ring was cut. The computed creep rate lambda did not differ between the segments. Compared to constant calculated from pig aorta and coronary artery, it showed that alpha agreed well (within 5%), eta was three times larger than that for vascular tissue, and lambda ranged +/-40% from the value of the pig coronary artery and was a third of the value of pig aorta. The change of opening angle over time for all the small intestine segments fits well to the standard linear spring-dashpot model. This viscoelastic constant of the rat small intestine is fairly homogenous along its length. The data obtained from this study add to a base set of biomechanical data on the small intestine and provide a reference state for comparison to other tissues, diseased intestinal tissue or intestinal tissue exposed to drugs or chemicals.

Airway-directed gene transfer of interleukin-10 using recombinant Sendai virus effectively prevents post-transplant fibrous airway obliteration in mice

Bronchiolitis obliterans (BO) after lung transplantation prevents a satisfactory prognosis, and recent studies suggested that interleukin-10 (IL-10) gene transfer to distant organs could inhibit BO in rodent models. Although delivery of the therapeutic gene to a local airway would be favored to minimize systemic effects, current limitations include lower gene transfer efficiency to airway epithelium. As recombinant Sendai virus (SeV) can produce dramatically efficient gene transfer to airway epithelium, we determined if SeV-mediated IL-10 gene transfer to the local airway would inhibit bronchial fibrous obliteration in murine tracheal allografts. Administration of cyclosporine A (CsA) significantly promoted not only recovery of the injured airway epithelium but also SeV-mediated IL-10 expression (CsA- versus CsA+ =228+/-78 versus 3627+/-1372 pg/graft with 5 x 10(7) pfu), thereby suggesting the requirement of epithelia for efficient gene transfer. Even at the highest expression, no significant leakage of IL-10 was evident in the systemic circulation, and the induction of interferon-gamma was completely diminished on day 7 by IL-10 gene transfer. As a result, luminal loss was significantly prevented in allografts treated with SeV-IL-10 (luminal opening, all control groups: 0% respectively, and SeV-IL-10 5 x 10(7) pfu: 25.7+/-10.5%), an effect that was enhanced by short-term CsA treatment (SeV-IL-10 5 x 10(7) pfu with CsA: 63.7+/-12.7%). We propose that SeV is a useful vector that can target airway epithelium to prevent BO avoiding putative systemic effect.

Concentration polarization of fluorescent dyes in rat descending colonic crypts: evidence of crypt fluid absorption.

1. Using confocal microscopy, the rate of fluid absorption into isolated perifused descending rat colonic crypt lumens is estimated from the concentration polarization and distribution of fluorescein sulphonate (FS) and fluorescein isothiocyanate-dextran (FITC-dextran; molecular weight, 10,000) within the crypt lumens and pericryptal fluid. 2. The probe dyes enter the crypt via the luminal opening, are concentrated in the lumen, then escape into the pericryptal space via the paracellular spaces spanning the crypt wall. 3. FITC-dextran is maximally accumulated at a luminal depth of 60 microns to 5 times the concentration at the crypt opening (p < 0.001) and penetrates 150-200 microns along the lumen. FS is maximally accumulated within crypt lumen close to the opening. At crypt luminal depths 10-60 microns from the opening FS is accumulated by a factor of 1.5-2.0 above that found in HgCl2-treated tissue (p < 0.001). 4. Dye enters the crypt lumen slowly from the basal side, but from this side does not accumulate above the bathing solution concentration. 5. HgCl2 (20 microM) or theophylline (10 mM) completely inhibit concentrative accumulation of FITC-dextran and FS within the crypts and pericryptal space (p < 0.001). 6. Computer simulation of the dye uptake indicates that the rate of water flow into the crypt luminal opening is 1 x 10(-3) cm s-1 which is equivalent to 15 microliters (cm mucosa)-2 h-1. Approximately 75% of the fluid entering the crypt is abosrbed across the proximal 50 microns of crypt wall as a consequence of the large osmotic pressure gradient between the pericryptal and crypt luminal solutions. A pericryptal diffusion barrier with lower permeability than that across the crypt wall is required to simulate dye accumulation in the pericryptal space. Differences between FITC-dextran and FS accumulation are explained by the lower diffusion coefficient within the crypt lumen, and lower crypt wall permeability of FITC-dextran.

Gross and histological characterization of endometrial tissues from SLA miniature pigs with cystic endometrial hyperplasia.

Cystic endometrial hyperplasia (CEH) is a uterine disorder characterized by the formation of large numbers of cysts in the endometrium. The purpose of this study was to examine and characterize cell types in the endometrium associated with the cysts and uterine glands. No apparent histological differences between CEH-involved and normal uterine columnar epithelium were found. Endometrial glands in CEH-involved and normal uteri were lined with simple or ciliated columnar epithelial cells and surrounded by lamellar connective tissue. The cyst epithelium appeared to be stretched obliquely and compressed so that both the cells and nuclei were horizontally oriented relative to the cyst lumen and were surrounded by lamellar connective tissue. Electron microgaphs revealed an abnormally high number of mitochondria in the cystic cells as compared to normal glandular cells. In conclusion, CEH is characterized by the formation of cysts which develop from the uterine glandular tissue. Epithelial cells lining the glands appeared to be distorted, possibly in response to internal pressure from increased volume due to high metabolic activity, and/or no uterine luminal opening.

Endoscopic Nd: YAG laser therapy as palliative treatment for advanced adenocarcinoma of the gastric cardia

Fifteen patients with advanced adenocarcinoma of the gastric cardia were treated with endoscopic neodymium: yttrium aluminum garnet laser therapy. Four patients developed recurrence after previous surgery. In 7 patients, a decision was made at exploration that a palliative operation was not feasible. In the remaining 4 patients, surgery was not considered because of widespread disease or the patient's condition. Fourteen of fifteen were classified as stage IV (tumor, node, metastasis). Tumors ranged in length from 3 to 10 cm (mean 6.3). Luminal opening was 4 mm or less in 12 patients. The mean number of treatments required to alleviate symptoms and remove obstruction was 2.8 (range 1–5) and the mean number of days required was 5.7 (range 1–12). An average of 6129 W/s were given per treatment and the mean total energy was 17,570 W/s. Luminal diameter at the narrowest segment increased from 3.3 mm before treatment to 12.1 mm after treatment. Clinical benefit in terms of increased food intake was demonstrated in all patients. No major complications directly attributable to laser therapy were seen. The overall results are encouraging and hold promise for a patient population in whom the therapeutic options are generally very limited.