[Recommendations for training courses in bronchoscopy]. / Empfehlungen zu Trainingskursen in der Bronchoskopie.

Bronchoscopic training courses are an essential part of the education in bronchoscopy for all kinds of specialisations and professions performing such investigations. All aspects of the application should be mentioned during a course. These recommendations are necessary because the number of bronchoscopies performed in the last years has increased due to the increasing number of patients, improved equipment and better availability. Courses should provide the basic knowledge including main points of indications, preconditions for the procedure and decisions of consequence after bronchoscopy. Participants should be trained in the skills of correct handling and performing flexible bronchoscopies in training dummies. Necessary competence requirements on the course instructor are adequate professional qualifications, paedagogic skills and the availability of appropriate teaching material. Quality assurance of the course should be achieved by consequent evaluation. A widely spread field of bronchoscopic applications can improve patient care in many medical specialisations.

EUELC project: a multi-centre, multipurpose study to investigate early stage NSCLC, and to establish a biobank for ongoing collaboration.

The European Early Lung Cancer (EUELC) project aims to determine if specific genetic alterations occurring in lung carcinogenesis are detectable in the respiratory epithelium. In order to pursue this objective, nonsmall cell lung cancer (NSCLC) patients with a very high risk of developing progressive lung cancer were recruited from 12 centres in eight European countries: France, Germany, southern Ireland, Italy, the Netherlands, Poland, Spain and the UK. In addition, NSCLC patients were followed up every 6 months for 36 months. A European Bronchial Tissue Bank was set up at the University of Liverpool (Liverpool, UK) to optimise the use of biological specimens. The molecular-pathological investigations were subdivided into specific work packages that were delivered by EUELC Partners. The work packages encompassed mutational analysis, genetic instability, methylation profiling, expression profiling utilising immunohistochemistry and chip-based technologies, as well as in-depth analysis of FHIT and RARbeta genes, the telomerase catalytic subunit hTERT and genotyping of susceptibility genes in specific pathways. The EUELC project engendered a tremendous collaborative effort, and it enabled the EUELC Partners to establish protocols for assessing molecular biomarkers in early lung cancer with the view to using such biomarkers for early diagnosis and as intermediate end-points in future chemopreventive programmes.

One polypeptide with two aminoacyl-tRNA synthetase activities.

The genome sequences of certain archaea do not contain recognizable cysteinyl-transfer RNA (tRNA) synthetases, which are essential for messenger RNA-encoded protein synthesis. However, a single cysteinyl-tRNA synthetase activity was detected and purified from one such organism, Methanococcus jannaschii. The amino-terminal sequence of this protein corresponded to the predicted sequence of prolyl-tRNA synthetase. Biochemical and genetic analyses indicated that this archaeal form of prolyl-tRNA synthetase can synthesize both cysteinyl-tRNA(Cys) and prolyl-tRNA(Pro). The ability of one enzyme to provide two aminoacyl-tRNAs for protein synthesis raises questions about concepts of substrate specificity in protein synthesis and may provide insights into the evolutionary origins of this process.

The adaptor hypothesis revisited.

As originally postulated in Crick's Adaptor hypothesis, the faithful synthesis of proteins from messenger RNA is dependent on the presence of perfectly acylated tRNAs. The hypothesis also suggested that each aminoacyl-tRNA would be made by a unique enzyme. Recent data have now forced a revision of this latter point, with an increasingly diverse array of enzymes and pathways being implicated in aminoacyl-tRNA synthesis. These unexpected findings have far-reaching implications for our understanding of protein synthesis and its origins.

[Endobronchial ultrasound for diagnosis of the mediastinum]. / Endobronchialer Ultraschall zur Diagnostik im Mediastinum.

The development of endobronchial ultrasound (EBUS) is one of the most important advances in bronchoscopy in recent years. Two different techniques are available which improve sonographic diagnostics of the mediastinum and staging in patients with lung and non-lung cancer. Radial EBUS and the technique of ultrasound-controlled transbronchial needle aspiration (TBNA) are now routine practice in many pulmonary centers. Their clinical application and diagnostic benefit have been established in many studies comparing them with conventional radiologic methods and other diagnostic procedures. Endobronchial ultrasound as a diagnostic tool is expected to gain importance in the near future. Especially the method combining EBUS and TBNA may replace more invasive methods such as mediastinoscopy for evaluating patients with unknown mediastinal lesions or for staging patients with lung cancer.

Endobronchial ultrasound-guided transbronchial lung biopsy in fluoroscopically invisible solitary pulmonary nodules: a prospective trial.

STUDY OBJECTIVES: Transbronchial biopsy (TBBX) for solitary pulmonary nodules (SPNs) is usually performed under fluoroscopic guidance, but the diagnostic yield depends on lesion size and varies widely. Nodules < 3 cm frequently cannot be visualized fluoroscopically. An alternative guidance technique, endobronchial ultrasound (EBUS), also allows visualization of pulmonary nodules. This study assessed the diagnostic yield of EBUS-guided TBBX in fluoroscopically invisible SPNs. DESIGN: The study was a prospective trial using a crossover design. PATIENTS AND METHODS: All patients with SPNs and indications for bronchoscopy were included in the study. An EBUS-guided examination was performed in patients with fluoroscopically invisible nodules. The EBUS probe was introduced through a guide catheter into the presumed segment. If a typical ultrasonic picture of solid tissue could be seen, the probe was removed and the catheter left in place. The biopsy forceps were introduced and specimens taken. RESULTS: One hundred thirty-eight consecutive patients with SPNs were examined. Of those, 54 patients presented with SPNs that could not be visualized with fluoroscopy. The mean diameter of the nodules was 2.2 cm. In 48 patients (89%), the lesion was localized with EBUS, and in 38 patients (70%) the biopsy established the diagnosis. The 16 patients with undiagnosed SPNs were referred for surgical biopsy; 10 of those lesions were malignant and 6 were benign. The diagnosis in nine patients (17%) saved the patients from having to undergo a surgical procedure. The only complication was a pneumothorax in one patient. CONCLUSIONS: EBUS-guided TBBX is a safe and very effective method for SPNs that cannot be visualized by fluoroscopy. The procedure may increase the yield of endoscopic biopsy in patients with these nodules and avert the need for surgical procedures.

Encapsulation of islets in rough surface, hydroxymethylated polysulfone capillaries stimulates VEGF release and promotes vascularization after transplantation.

The transplantation of encapsulated islets of Langerhans is one approach to treat type 1 diabetes without the need of lifelong immunosuppression. Capillaries have been used for macroencapsulation because they have a favorable surface-to-volume ratio and because they can be refilled. It is unclear at present whether the outer surface of such capillaries should be smooth to prevent, or rough to promote, cell adhesions. In this study we tested a new capillary made of modified polysulfone (MWCO: 50 kDa) with a rough, open-porous outer surface for islet transplantation. Compared with free-floating islets, encapsulation of freshly isolated rat islets affected neither the kinetics nor the efficiency of glucose-induced insulin release in perifusion experiments. Free-floating islets maintained insulin secretion during cell culture but encapsulated islets gradually lost their glucose responsiveness and released VEGF. This indicated hypoxia in the capillary lumen. Transplantation of encapsulated rat islets into diabetic rats significantly reduced blood glucose concentrations from the first week of implantation. This hypoglycaemic effect persisted until explantation 4 weeks later. Transplantation of encapsulated porcine islets into diabetic rats reduced blood glucose concentrations depending on the islet purity. With semipurified islets a transient reduction of blood glucose concentrations was observed (2, 8, 18, 18 days) whereas with highly purified islets a sustained normoglycaemia was achieved (more than 28 days). Explanted capillaries containing rat islets were covered with blood vessels. Vascularization was also observed on capillaries containing porcine islets that were explanted from normoglycaemic rats. In contrast, on capillaries containing porcine islets that were explanted from hyperglycemic rats a fibrous capsule and lymphocyte accumulations were observed. No vascularization on the surface of transplanted capillaries was observed in the absence of islets. In conclusion, encapsulated islets can release VEGF, which appears to be an important signal for the vascularization of the capillary material. The rough, open-porous outer surface of the polysulfone capillary provides a site well suited for vascular tissue formation and may allow a prolonged islet function after transplantation.

Long-term outcome of conservative treatment in patients with diverticulitis of the sigmoid colon.

INTRODUCTION: The indication for surgery after conservative treatment of acute diverticulitis is still under debate. This is partly as a result of limited data on the outcome of conservative management in the long run. We therefore aimed to determine the long-term results of conservative treatment for acute diverticulitis. METHODS: The records of all patients treated at our institution for diverticulitis between 1985 and 1991 were reviewed (n=363, median age 64 years, range 29-93). Patients who received conservative treatment were interviewed in 1996 and 2002 [follow-up time 7 years 2 months (range 58-127 months) and 13 years 4 months (range 130-196 months). RESULTS: A total of 252 patients (69%) were treated conservatively, whereas 111 (31%) were operated on. At the first follow-up, 85 patients treated conservatively had died, one of them from bleeding diverticula. A recurrence of symptoms was reported by 78 of the remaining 167 patients, and 13 underwent surgery. At the second follow-up, one patient had died from sepsis after perforation during another episode of diverticulitis. Thirty-one of the 85 patients interviewed reported symptoms and 12 had been operated on. In summary, at the second follow-up interview, 34% of patients treated initially had had a recurrence and 10% had undergone surgery. No predictive factors for the recurrence of symptoms or later surgery could be determined. CONCLUSION: Despite a high rate of recurrences after conservative treatment of acute diverticulitis, lethal complications are rare. Surgery should thus mainly be undertaken to achieve relief of symptoms rather than to prevent death from complications.

Correlation of imaging techniques to histopathology in patients with diabetic foot syndrome and clinical suspicion of chronic osteomyelitis. The role of high-resolution ultrasound.

OBJECTIVE: To investigate the role of ultrasound in the diagnosis of osteomyelitis in the diabetic foot compared with magnetic resonance imaging (MRI), bone scintigraphy (BS), and plain film radiography (PFR). RESEARCH DESIGN AND METHODS: We investigated 19 consecutive diabetic patients (2 women, 17 men, age 60.7 +/- 9.8 years, BMI 27.0 +/- 3.8 kg/m2) with clinical suspicion of bone infection of the foot. A high-resolution ultrasound system (Esaote/Biosound, Munich) with a linear array transducer up to 13.0 MHz was used. The prospective and blinded results of each method were compared with histopathology as the reference method after metatarsal resection. RESULTS: In 14 of 19 patients, histopathology confirmed osteomyelitis. Ultrasound showed a sensitivity of 79% (PFR, 69%; BS, 83%; MRI, 100%), a specificity of 80% (PFR, 80%; BS, 75%; MRI, 75%), a positive predictive value of 92% (PFR, 90%; BS, 91%; MRI, 93%), and a negative predictive value of 57% (PFR, 50%; BS, 60%; MRI, 100%). CONCLUSIONS: Our data indicate that ultrasound might have a better diagnostic power for detecting chronic osteomyelitis in the diabetic foot than PFR and has similar sensitivity and specificity as BS. MRI is superior to the other three methods. We conclude that the use of ultrasound in the management of the diabetic foot is worthy of further investigation.

Blood flow measurements with [(15)O]H2O and [18F]fluoride ion PET in porcine vertebrae.

A dual positron emission tomography (PET) tracer study with [18F]fluoride and the freely diffusible tracer [(15)O]H2O was performed to measure the capillary transport of [18F]fluoride and to evaluate the potential of [18F]fluoride ion PET to quantitate bone blood flow. Under the condition of a high predictable single-pass extraction fraction (E(F)) for [18F]fluoride, the [18F]fluoride ion influx transport constant (K1F), derived from kinetic [18F]fluoride ion PET measurements, can be used to estimate bone blood flow. Bone blood flow was measured in vertebral bodies by dynamic [(15)O]H2O PET during continuous ventilation with N2O, O2, and Isoflurane (FiO2 = 0.3) in seven adult mini pigs, followed by dynamic [18F]fluoride ion PET. The mean blood flow measured by [(15)O]H2O (FlowH2O) was 0.145 +/- 0.047 ml x minute(-1) x ml(-1) and the mean K1F was 0.118 +/- 0.031 ml x minute(-1) x ml(-1), respectively (mean +/- SD). Regional analysis showed excellent agreement between FlowH2O and K1F at low flow and a significant underestimation of flow by K1F relative to FlowH2O in regions of normal and elevated flow. The observed relationship between parameters followed the Renkin-Crone distribution. The permeability-surface product was determined as 0.25 minute(-1) for vertebral bodies consisting of a mixture of trabecular and cortical bone. We conclude that [18F]fluoride ion PET can be used to estimate bone blood flow in low and normal flow regions, as long as the flow dependency of the E(F) is taken into consideration. Above blood flow values of 0.2 to 0.35 ml x minute(-1) x ml(-1), the magnitude of K1F is increasingly independent on blood flow because diffusion limits tracer transport.

Parathyroid hormone after adenectomy for primary hyperparathyroidism. A study of peptide hormone elimination kinetics in humans.

The study of the elimination kinetics of peptide hormones in humans is limited, because determining hormone levels in different compartments is difficult. We calculated the elimination kinetics of intact PTH (1-84) after adenoma removal in primary hyperparathyroidism, based on a 2-compartment model. In 12 patients, blood samples were drawn in short intervals preoperatively, during surgery, and up to 4 days postoperatively. Plasma levels of PTH (1-84), calcium (Ca), and inorganic phosphate were determined. PTH (1-84) levels remained constant before surgery and during adenoma preparation; 2.5 min after clamping of the adenoma's blood supply, PTH (1-84) decreased (34.9 +/- 4.8 vs. 23.3 +/- 2.9 pmol/L, mean +/- SEM, P < 0.001) and then reached a minimum of 0.96 +/- 0.06 pmol/L at 5 h. The elimination half-lives for PTH (1-84) were 3.43 +/- 0.1 min and 81.7 +/- 12.7 min. Ionized Ca started to decrease 30 min after adenoma removal (1.58 +/- 0.04 vs. 1.56 +/- 0.04 pmol/L, P < 0.001). This decrease was paralleled by a decrease in total Ca. Inorganic phosphate increased 24 h after adenoma removal. In conclusion, PTH (1-84) elimination after adenectomy is characterized by a rapid initial decrease and a subsequent prolonged period with a lower elimination rate. This elimination pattern may also apply to other human peptide hormones.

The heterotrimeric Thermus thermophilus Asp-tRNA(Asn) amidotransferase can also generate Gln-tRNA(Gln).

Thermus thermophilus strain HB8 is known to have a heterodimeric aspartyl-tRNA(Asn) amidotransferase (Asp-AdT) capable of forming Asn-tRNA(Asn) [Becker, H.D. and Kern, D. (1998) Proc. Natl. Acad. Sci. USA 95, 12832-12837]. Here we show that, like other bacteria, T. thermophilus possesses the canonical set of amidotransferase (AdT) genes (gatA, gatB and gatC). We cloned and sequenced these genes, and constructed an artificial operon for overexpression in Escherichia coli of the thermophilic holoenzyme. The overproduced T. thermophilus AdT can generate Gln-tRNA(Gln) as well as Asn-tRNA(Asn). Thus, the T. thermophilus tRNA-dependent AdT is a dual-specific Asp/Glu-AdT resembling other bacterial AdTs. In addition, we observed that removal of the 44 carboxy-terminal amino acids of the GatA subunit only inhibits the Asp-AdT activity, leaving the Glu-AdT activity of the mutant AdT unaltered; this shows that Asp-AdT and Glu-AdT activities can be mechanistically separated.

A new applicator, positionable to the center of tracheobronchial lumen for HDR-IR-192-afterloading of tracheobronchial tumors.

A new bronchial applicator for afterloading irradiation is introduced which can be positioned to the center of the tracheobronchial lumen. The central position in the lumen leads to a clear improvement of dose distribution. The applicator is built on the principle of a coaxial tube. Parts of the outer cover can be expanded to baskets and effect a distance of the radiation source from the bronchial mucosa or tumor surface, and at the same time, expend a relief of extreme contact doses. No obstruction of the respiratory system through the positioning device will be caused. The positionable bronchial applicator seems to be suitable for reducing complications caused through high contact doses and irregular dose distributions and may be able to improve the results of endoluminal radiotherapy.

Tacrolimus impairs wound healing: a possible role of decreased nitric oxide synthesis.

BACKGROUND: The effect of the immunosuppressant tacrolimus on wound healing is not known. Tacrolimus has been shown to decrease nitric oxide synthesis. The systemic inhibition of wound nitric oxide synthesis leads to impaired healing. METHODS: We studied the effect of systemic tacrolimus treatment on wound-breaking strength and collagen deposition 10 days after wounding in rats and to correlate the outcome of healing with wound nitric oxide synthesis. Beginning at the day of wounding, rats were treated once daily by intraperitoneal injections with 0.5, 1.0, or 2.0 mg tacrolimus/kg body weight. Nitrite and nitrate were measured in wound fluid as an index of wound nitric oxide synthesis. Expression of inducible nitric oxide synthase in the wound was investigated by immunohistochemistry. Splenic lymphocytes were tested for proliferative activity. Tacrolimus levels in blood and wound fluid were measured by enzyme-linked immunosorbent assay. RESULTS: Systemic tacrolimus treatment was well tolerated by all rats. Tacrolimus accumulated in wound fluid. Tacrolimus levels in wound fluid were found to be approximately 10-fold higher than blood levels (P < 0.001). Tacrolimus (2.0 mg/kg/day) reduced wound-breaking strength (P < 0.01) and collagen deposition (P < 0.05). This was paralleled by decreased wound nitrite + nitrate levels (P < 0.001) and wound-inducible nitric oxide synthase expression. Splenic lymphocyte proliferative activity was significantly decreased by 1.0 and 2.0 mg tacrolimus/kg body weight/day (P < 0.05), indicating that the tacrolimus doses used were immunosuppressive. CONCLUSION: Our data show for the first time that tacrolimus impairs wound healing, and this is reflected by diminished wound nitric oxide synthesis.

Energy-dependent injury to cultured sinusoidal endothelial cells of the rat liver in UW solution.

The critical injury to liver during cold preservation is believed to occur to the sinusoidal endothelium. In this study the viability of cultured sinusoidal endothelial cells from rat liver was assessed during storage in University of Wisconsin solution at 4 degrees C. The vast majority of cells (83 +/- 12%) died within 24 hr of storage. Addition of KCN (1 mM) to the solution to simulate hypoxia markedly increased survival: only 3 +/- 2% of cells had lost viability after 24 hr in the presence of cyanide. Further experiments showed that other inhibitors of mitochondrial ATP formation (antimycin A 1 microM, rotenone 1 microM, oligomycin 10 microM, carbonyl cyanide m-chlorophenylhydrazone 1 microM) were protective as well, whereas glucose (10 mM) greatly diminished the protective effect of cyanide (loss of viability 38 +/- 7% after 24 hr). ATP measurements confirmed the correlation between the energy state of the cells and cell death: ATP levels after 6 hr of incubation were 19.9 +/- 4.0 nmol/10(6) cells in UW solution, 13.7 +/- 2.9 nmol/10(6) cells in UW + glucose, 6.9 +/- 1.9 nmol/10(6) cells in UW + KCN + glucose and 1.9 +/- 1.5 nmol/10(6) cells in UW + KCN. In contrast to the protective effect observed in UW solution, addition of KCN to Krebs-Henseleit buffer led to increased endothelial cell damage upon cold storage. We therefore conclude that in UW solution damage to the sinusoidal endothelium is energy-dependent.

Long-term outcome and lung cancer incidence in patients with hemoptysis of unknown origin.

STUDY OBJECTIVE: To provide current data on the long-term outcome and incidence of lung cancer in a large cohort of patients with hemoptysis of unknown origin. DESIGN: A retrospective chart review followed by a telephone interview for follow-up. SETTING: A university-affiliated tertiary referral center for pulmonary diseases. PATIENTS: Seven hundred twenty-two patients who presented with hemoptysis from January 1990 to December 1993. One hundred thirty-five patients were identified as having hemoptysis of unknown origin. RESULTS: One hundred thirty-five patients (19%) had hemoptysis of unknown origin; follow-up data were obtained in 115 patients, of whom 100 were still alive. The mean time of observation was 6.6 years after initial presentation. Lung cancer developed in 7 of 115 patients (6%) and was unresectable once detected; all of these patients were smokers > 40 years old, and malignancy developed within 3 years after first presentation. CONCLUSIONS: Hemoptysis of unknown origin is present in a minority of patients presenting with hemoptysis if evaluated at a referral center for pulmonary diseases. Lung cancer seems to be increasing in these patients compared to previous studies, and closer follow-up or additional testing may be indicated in the defined population at risk.

Successful bronchoscopic placement of tracheobronchial stents without fluoroscopy.

BACKGROUND: Tracheobronchial stenting is performed increasingly often. Fluoroscopic control, which leads to significant radiation exposure for patients and staff, is recommended for the placement of metal stents. METHODS: All consecutive patients referred to two airway centers in need of airway stenting who received stents (Ultraflex; Boston Scientific, Natick, MA) underwent placement using endoscopic guidance only. All data were collected in an ongoing continuous database. RESULTS: One hundred stents were placed in 96 patients for central airway obstruction, and the data were reviewed. Stents were placed in all locations within the central airways for a variety of indications but mainly for malignant obstruction. No complications occurred, and all stents were placed satisfactorily. CONCLUSION: At centers with dedicated airway teams, Ultraflex stents can be quickly and safely inserted without the need for fluoroscopy. This saves radiation exposure to patients and to staff and may lead to a more cost-effective procedure.

Aspirin does not increase bleeding complications after transbronchial biopsy.

STUDY OBJECTIVES: The present study was performed to determine whether the risk of bleeding after transbronchial lung biopsy is increased in patients taking aspirin. DESIGN: Prospective cohort study. PATIENTS AND INTERVENTIONS: After excluding patients with other coagulation problems, 1,217 patients who had undergone transbronchial lung biopsy during a prospective 1.5-year study period were included in this study. The use of aspirin was not discontinued before the procedure. Two hundred eighty-five patients (23%) had consumed aspirin within 24 h of the procedure, and most of them (82%) used aspirin on a daily basis. Transbronchial biopsies were performed, and the bleeding incidence was compared between the groups. RESULTS: A total of 57 patients (4.7%) experienced procedure-related bleeding. Minor bleeding occurred in 5 of 285 patients (1.8%) taking aspirin and in 27 of 932 control patients (2.9%; not significant). Moderate bleeding was seen in 3 of 285 patients (1.1%) in the aspirin group and in 13 of 932 patients (1.4%) in the control group (not significant). Major bleeding occurred in only 9 patients, 2 of 285 (0.9%) in the aspirin group and 7 of 932 (0.8%) in the control group (not significant). All bleeding was controlled by endoscopic means, and there were no fatalities and no need for blood transfusions. CONCLUSIONS: We conclude that the risk of severe bleeding after transbronchial lung biopsy is small (ie, < 1%) and that the use of aspirin is not associated with any increased risk of bleeding.

Endobronchial ultrasound.

Endobronchial ultrasound (EBUS) is a new diagnostic tool, which has expanded the view of the bronchoscopist beyond the confinements of the airways. It has great potential for diagnosis of mediastinal processes and staging of lung cancer. These will be discussed and illustrated. EBUS will become a superior tool for staging of lung cancer, and several comparative studies on EBUS as compared with standard techniques in order to assess its role in the staging procedure are just on their way or already completed.

Defense mechanism and macroscopic tumor growth in lung tissue.

A total of 126 resection specimens from malignant lung tumors were cut into serial sections, and tumor volume and macroscopic growth pattern were computed. Four characteristic tumor growth patterns could be separated: Tumors growing in bizarre, irregular shapes; Tumors growing in spheroid shapes; Tumors growing in ellipsoid shapes; Tumors growing in mixed growth pattern. The immunologic response of the host tissue was analyzed grading the number of lymphocytes, plasma cells, macrophages in and at the boundary of the tumor tissue. Lymphocytic subpopulations were analyzed in 46 cases using monoclonal antibodies (BS3/BS4; T3, OKT4, OKT8, OKT11, OKT14). The majority of lymphocytes were T-lymphocytes and monocytes in cases with inflammatory response of host tissue. The ratio of inducer/helper subset (OKT4+) compared to suppressor/cytotoxic subset (OKT8+) was similar in expression as reported for circulating peripheral T-lymphocytes. The different growth patterns depend upon cell type of tumor, immunologic response of the host tissue, and tumor volume. The findings indicate that tumor progression into lung tissue is partly due to "localized metastatic growth" of different tumor cell subpopulations.