Novel approaches utilizing robotic navigational bronchoscopy: a single institution experience.

The effective biopsy of pulmonary nodules is crucial to early diagnosis and consequent effective treatment for patients. As a relatively new procedure, few studies look at the effectiveness of the Monarch system in achieving this goal. The aim of this study is to describe the validity of the Monarch-guided robotic navigational bronchoscopy as an effective diagnostic method for pulmonary disease. A secondary aim is to describe the validity of dye localization using the robotic platform to improve the diagnostic accuracy of surgical biopsies in suspicious subcentimeter nodules. This observational cohort study includes patients who underwent robotic navigational bronchoscopy at John Muir Health between July 8, 2020 and October 11, 2021. Some underwent the navigational bronchoscopy in conjugation with a dye localization procedure. Patient data were collected from the institutional database. We measured specificity, sensitivity, and likelihood ratios. A total of 69 patients underwent robotic navigational bronchoscopy. The procedure had a specificity and sensitivity of 100% and 91.3%, respectively. Additionally, 28 patients underwent robotic navigational bronchoscopy in conjugation with dye localization. The specificity and sensitivity for the combined procedures was 100% and 100%, respectively. Robotic Navigational Bronchoscopy can be a successful diagnostic technique to diagnose pulmonary disease quickly and accurately. The technique allowed for the effective biopsy of traditionally difficult to access nodules. Additionally, by combining dye localization techniques, surgical biopsy of the nodules significantly improved the diagnostic accuracy. This single anesthetic event can potentially lead to earlier diagnosis, staging, and treatment of early stage lung cancers.

Massive gastrointestinal bleeding: an unusual case of asymptomatic extrarenal, visceral, fibromuscular dysplasia.

Extrarenal fibromuscular dysplasia causing gastro-intestinal bleeding without other manifestations and especially sparing renal vasculature is uncommon. The diagnosis of this entity is usually made by radiographic appearance and the treatment is controversial. To our knowledge only seven cases of visceral fibromuscular dysplasia as a primary manifestation of the disease have been described, symptoms range from abdominal pain to gangrene. This is the first case of visceral fibromuscular dysplasia presenting with otherwise asymptomatic gastrointestinal bleeding, without bowel necrosis or ischemic changes. We provide a review of the literature.

The essential role of the mitochondria and reactive oxygen species in Cisplatin-mediated enhancement of fas ligand-induced apoptosis in malignant pleural mesothelioma.

Cytotoxic chemotherapeutic drugs such as cisplatin (CDDP) synergistically interact with soluble Fas ligand (sFasL) to mediate profound induction of apoptosis in cancer cells, particularly those refractory to this death-inducing ligand. The goal of this study was to evaluate the roles of the mitochondria-dependent apoptotic cascade and the CDDP-generated reactive oxygen species (ROS) in mediating the supra-additive enhancement of cytotoxicity and apoptosis in combination-treated malignant pleural mesothelioma (MPM) cells. MPM cells were treated with sequential CDDP/sFasL in vitro. Cell viability and apoptosis were determined by MTT and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assays. Stable transfectants expressing high levels of Bcl2 were created by retroviral gene transfer. Specific proteolytic activity of caspases 3, 8, and 9 were measured using fluorescent substrates. Pretreating MPM cells with CDDP increased their susceptibility to sFasL by 2- to more than 20-fold. Overexpression of either Bcl-2, the selective caspase 9 inhibitor z-LEHD-fmk, or the antioxidant N-acetylcysteine significantly abrogated combination-induced cytotoxicity and apoptosis. Moreover, the robust activation of caspase 8 in combination-treated cells was completely suppressed by Bcl-2 overexpression, thus implicating a mitochondria-mediated amplification feedback loop. As an in vivo correlate, sequential intraperitoneal administration of CDDP and sFasL significantly inhibited the growth of intraperitoneal MPM human xenografts in nude mice. Our data indicate that the mitochondria-dependent feedback loop of the caspase activation cascade and the generation of ROS are both essential in mediating profound cytotoxicity and apoptosis of MPM cells treated with CDDP and sFasL. This mechanistic study establishes a the translational framework for the clinical application of sequential CDDP/sFasL in the treatment of MPM.

Bariatric surgery in adolescents: recent national trends in use and in-hospital outcome.

OBJECTIVES: To analyze recent nationwide trends in the use of adolescent bariatric surgery and to compare early postoperative outcomes of adolescents and adults undergoing these procedures. DESIGN: Analysis of national administrative data by using survey analysis techniques. SETTING: Data obtained from the Nationwide Inpatient Sample from 1996 to 2003. PARTICIPANTS: Adolescents (aged <20 years) and adults undergoing bariatric surgery. Intervention Bariatric surgery. MAIN OUTCOME MEASURES: Population-based case rates, major postoperative complications, length of hospital stay, hospital charges, and mortality. RESULTS: The population-based annual adolescent bariatric case volume varied little between 1996 and 2000 but more than tripled from 2000 to 2003. Despite this trend, only 771 bariatric procedures were performed in adolescents in 2003, representing fewer than 0.7% of bariatric procedures performed nationwide. Univariate comparison with data from 2003 showed a similar in-hospital complication rate in adolescents and adults but a significantly shorter length of stay among adolescents. Although in-hospital mortality was observed in 0.2% of adults, no in-hospital deaths were observed in any adolescents. CONCLUSIONS: Although procedure rates have increased recently, bariatric surgery in adolescents remains an uncommonly performed procedure. These data support efforts to align bariatric surgery programs for adolescents initially with higher volume programs for adults and to develop multicenter collaborative studies directed at defining the short- and long-term effect of bariatric surgery in morbidly obese adolescents.

Enhancement of Apo2L/TRAIL-mediated cytotoxicity in esophageal cancer cells by cisplatin.

Although expressing adequate levels of functional tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptors DR4/DR5, significant proportion of cancer cells exhibit resistance to the cytotoxic effect of this ligand. Exposure of Apo2L/TRAIL-refractory cancer cells to cytotoxic chemotherapeutic agents enhances their sensitivity to Apo2L/TRAIL cytotoxicity. This study aims to elucidate the molecular mechanism responsible for the cisplatin-mediated enhancement of Apo2L/TRAIL sensitivity in cultured esophageal cancer cells. Exposure of cancer cells to sublethal concentrations of cisplatin resulted in profound potentiation of their susceptibility to Apo2L/TRAIL cytotoxicity as indicated by 2- to >20-fold reduction in Apo2L/TRAIL IC50 values. Significant activation of caspase-8, caspase-9, and caspase-3 was observed only in cells treated with cisplatin/Apo2L/TRAIL combination and not in those exposed to either agent alone. More importantly, activation of these key caspases was significantly abrogated by overexpression of Bcl2 or by the selective caspase-9 inhibitor. This observation strongly suggested that caspase-8 activation in cells treated with the cisplatin/Apo2L/TRAIL combination was secondary to the mitochondria-mediated amplification feedback loop and activation of the executioner caspase-3 was dependent on the recruitment of the intrinsic pathway characteristic of the type II cell. Profound combination-mediated cytotoxicity and induction of apoptosis was completely suppressed either by Bcl2 overexpression or by inhibition of caspase-9 activity, which conclusively pointed to the essential role of the mitochondria-dependent death signaling cascade in this process. Cisplatin sensitizes esophageal cancer cells to Apo2L/TRAIL cytotoxicity by potentiation of the mitochondria-dependent death signaling pathway that leads to amplification of caspase activation, particularly caspase-8, by the feedback loop to efficiently induce apoptosis.

Cisplatin enhances apoptosis induced by a tumor-selective adenovirus expressing tumor necrosis factor-related apoptosis-inducing ligand.

BACKGROUND: Cancer cells frequently exhibit resistance to the cytotoxic effect of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Pretreatment of TRAIL-resistant cells with cisplatin sensitizes them to this ligand. Cisplatin also has been shown to enhance adenoviral transgene expression. OBJECTIVE: This study aims to evaluate the ability of cisplatin to enhance the expression and the cytotoxic effect of the tumor-specific adenoviral vector Ad/gTRAIL, which expresses a green fluorescent protein-TRAIL fusion protein. METHODS: Cultured cancer cells and normal human cells were infected with Ad/gTRAIL with or without cisplatin pretreatment. Adenoviral transgene expression was determined by using flow cytometry to measure green fluorescent protein fluorescence. Cytotoxicity was measured by using thiazolyl blue tetrazolium bromide assays and an apoptosis enzyme-linked immunosorbent assay kit. RESULTS: Green fluorescent protein-TRAIL fusion protein expression was significantly enhanced by cisplatin pretreatment in cancer cells. Cisplatin treatment before Ad/gTRAIL infection resulted in a 2- to 12-fold increase in green fluorescent protein fluorescence intensity across cancer lines. Although Ad/gTRAIL induced mild cytotoxicity in all cancer lines (inhibitory concentration of 50% values of >500 pfu/cell), pretreatment with cisplatin resulted in a dose-dependent enhancement of Ad/gTRAIL-mediated cytotoxicity, as indicated by the drastic reduction of inhibitory concentration of 50% values to 4 to 42 pfu/cell in all cell lines. There was no cytotoxicity noted in normal cells treated with both cisplatin and Ad/gTRAIL. CONCLUSION: Cisplatin pretreatment enhances Ad/gTRAIL cytotoxicity in malignant cells while not affecting normal cells. The mechanisms underlying this effect might include both enhancement of the susceptibility of cisplatin-treated cells to TRAIL and cisplatin-mediated enhancement of TRAIL expression in Ad/gTRAIL infected cells. These findings provide a rationale for development of Ad/gTRAIL-based therapy for thoracic malignancies.

Enhancement of depsipeptide-mediated apoptosis of lung or esophageal cancer cells by flavopiridol: activation of the mitochondria-dependent death-signaling pathway.

OBJECTIVE: Treating cancer cells with depsipeptide, a novel antitumor agent currently in a phase II clinical trial, causes potent upregulation of p21/WAF1 expression and cell arrest at G1 and G2 checkpoints. p21/WAF1 upregulation, however, impedes the ability of depsipeptide to induce significant apoptosis. This study was designed to determine whether flavopiridol, a synthetic cyclin-dependent kinase inhibitor known to inhibit p21 expression in tumor cells, could enhance depsipeptide-mediated apoptosis in cultured lung and esophageal cancer cells. METHODS: Lung or esophageal cancer cells were exposed to depsipeptide, flavopiridol, or a combination of depsipeptide and flavopiridol. Cytotoxicity and apoptosis were quantitated by means of (4,5-dimethylthiazo-2-yl)-2,5-diphenyl tetrazolium bromide and terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling-based assays, respectively. Cytosolic cytochrome c levels, caspase 9 activity, mitochondrial membrane depolarization, and dependence of apoptosis on caspase 9 in treated cells were studied to determine the role of the mitochondria in mediating apoptosis induced by this drug combination. RESULTS: Flavopiridol completely abolished depsipeptide-mediated dose-dependent upregulation of p21/WAF1 expression. Combining flavopiridol with depsipeptide resulted in a 3- to 8-fold reduction of depsipeptide inhibitory concentration of 50% values that was closely paralleled by synergistic enhancement of apoptosis (4- to 10-fold higher than levels of cell death induced by either drug alone) in all cancer cell lines. The essential role of mitochondria in mediating cell death was indicated by robust translocation of cytochrome c from the mitochondria into the cytosol, 2.5- to 5-fold activation of caspase 9, severe disruption of mitochondrial inner membrane potential, and complete inhibition of apoptosis by the selective caspase 9 inhibitor. More important, this drug combination was not toxic to primary normal epithelial cells derived from the airway or skin. CONCLUSION: The depsipeptide plus flavopiridol combination exhibits powerful and selective cytocidal activity against cancer but not normal cells. Apoptosis induced by this combination is mediated by the mitochondria-dependent death pathway.