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Biomedical subjects

R M Huber

Publications and source records attributed to R M Huber.

At least 55 records · Page 3Linked to original sources
PubMed2001

Fiberoptic bronchoscopic balloon dilatation in malignant tracheobronchial disease: indications and results.

STUDY OBJECTIVES: Bronchoscopic balloon dilatation (BBD) has become a valuable tool in the treatment of benign tracheobronchial stenoses. The objective of this study was to assess indications for and results of fiberoptic BBD in treating malignant lesions. DESIGN: One hundred twenty-six balloon dilatation procedures were performed in 78 patients with predominantly bronchial carcinoma. BBD was only performed when alternative modes of local treatment (eg, laser therapy or stent implantation) were not indicated or were inappropriate. Indications were symptomatic stenoses of the tracheobronchial tree: dyspnea or stridor (52%), retention pneumonia (15%), atelectasis (10%), retention of secretions (21%), or lung abscess (2%). RESULTS: Fifty-five percent of all procedures consisted of dilatations of tracheal or bronchial lesions (group 1). In 22% of procedures, a stent was dilated (group 2). In 13%, BBD was used to facilitate stent placement (group 3), and in 10% to enable the correct positioning of irradiation probes for brachytherapy (group 4). In group 1 and group 2, 2 of 2 lung abscesses resolved, 5 of 8 atelectases resolved, and 11 of 12 retention pneumonias resolved. Dyspnea improved in only 12 of 32 patients. No abscess recurred. Two pneumonias and two atelectases reappeared due to restenosis. Stent implantation and brachytherapy procedures were facilitated in 90% of cases. In 52% of cases, BBD was supported by high-frequency jet ventilation. Complications consisted of one fatal hemoptysis caused by a lacerated pulmonary artery, and minor bleeding not necessitating specific therapy. CONCLUSIONS: Fiberoptic BBD is useful in the management of airway stents prior to and postimplantation, as well as in the placement of brachytherapy catheters. BBD is also successful in the resolution of poststenotic lung abscesses, retention pneumonias, and atelectases.

Adult↗
PubMed2000

Detection of K-ras and p53 mutations in bronchoscopically obtained malignant and non-malignant tissue from patients with non-small cell lung cancer.

Molecular screening may increase the likelihood to identify early malignant lesions in non-small cell lung cancer. However the presence of gene mutations in non-malignant bronchial tissue has remained controversial. The present study was carried out to investigate systematically the presence of mutations of the K-ras and p53 gene in bronchial biopsies taken during routine bronchoscopy of normal as well as tumour tissues from a series of 40 patients with histologically verified non-small cell lung cancer (NSCLC). K-ras mutations were analysed with specific detection oligonucleotides, p53 mutations were examined by SSCP analysis. In all biopsies the wildtype of both K-ras and p53 could be detected. The overall frequency of mutations was 14 (35%) with 2 K-ras mutations (5%) and 12 mutations of the p53 gene (30%). In 3 cases (1 ras mutation, 2 p53 mutations) the same mutation could be shown in the tumour biopsy and in the distant normal control. In another case only the normal appearing tissue had a mutation of the p53 gene. All other mutations could be detected in the tumour tissue only. Our data confirm that K-ras mutations and p53 can be detected not only in malignant but also in non-malignant bioptic samples from patients with NSCLC. The use of molecular screening for the early detection of lung cancer may be a promising new approach.

Adenocarcinoma↗
PubMed2000

High-dose-rate brachytherapy: dose escalation in three-dimensional miniorgans of the human bronchial wall.

PURPOSE: High-dose-rate (HDR) brachytherapy of human lung cancer is well established, however fractionation schemes and dosages are based mainly on experience. The aim of this investigation was to study the effects of different doses of HDR iridium-192 on normal human bronchial epithelium in three-dimensional miniorgans of the human bronchial wall. METHODS AND MATERIALS: Forty-eight biopsies from normal bronchi were cultivated for 14 days and exposed at random to different doses of HDR iridium 192 (0 Gy, 30 Gy, 45 Gy, 60 Gy, or 75 Gy). Cell viability was assessed immediately after irradiation, after 4 or 18 days by fluorescent staining, and cell damage of the culture was analyzed by light microscopy. Lactate dehydrogenase (LDH) was measured in the supernatant for 4 days. RESULTS: There was no histologically apparent tissue damage regardless of the irradiation dose. The number of nonvital cells increased in irradiated miniorgans depending on the dose used (p < 0. 05 at 75 Gy). This effect occurred early and was less pronounced with time. LDH measurements showed an increase only in the first 24 hours. CONCLUSIONS: Our results confirm that normal bronchial epithelium has a high tolerance to early epithelial damage by irradiation. This model of human bronchial miniorgans is useful for further studies of the effects of irradiation on human bronchi.

Brachytherapy↗
PubMed2000

Flexible bronchoscopy: a safe method for metal stent implantation in bronchial disease.

BACKGROUND: Endoscopic bronchoplastic procedures, such as metal stent implantation, are for safety reasons and mainly performed using rigid bronchoscopy. Major complications, such as bleeding and accidental airway occlusion, are thought to be better managed with the rigid device. An increasing number of pneumologists, however, use the flexible fiberscope for endobronchial stenting. METHODS: Sixty-five stent implantations were performed in 51 patients with flexible fiberoptic bronchoscopy. We implanted 27 Tantalum Strecker stents (Boston Scientific Co, Watertown, MA), 20 Nitinol Accuflex stents (Boston Scientific Co) and 18 Wallstents (Schneider, Zurich, Switzerland). Underlying conditions were malignant disease in 84% and benign bronchial collapse in 16%. Sites of implantation were the trachea (45%), the main bronchi (35%), and other locations (20%). In 47 cases the patients received intravenous sedation combined with high frequency jet ventilation, and in 18 cases the patients were treated with topical anesthesia alone. RESULTS: Mean examination time was 58.3 (standard deviation 29.1) minutes. Eighty percent of patients experienced immediate clinical improvement in respiratory symptoms. Spirometric parameters (forced expiratory volume in one second, peak expiratory flow rate, forced vital capacity) increased. Complications included hypertension (17%), hypotension (12%), hypoxia (5%), bronchospasm (4%), initial displacement of the prosthesis (11%), and diameter mismatch between stent and bronchus (5%). All complications were managed safely. Relevant bleeding or asphyxia during the procedure has not been observed. Late stent migration was observed in 12% of cases. There were 3 fatalities within 30 days of stent placement which, however, were not attributed to the implantation technique. CONCLUSIONS: Flexible fiberoptic bronchoscopy is a safe and suitable method to perform endobronchial metal stent implantation. Complications were rare and not serious. Initial misplacement of the prosthesis occurred in some cases and necessitated removal and replacement within the same procedure.

Adult↗
PubMed2000

Maximal inspiratory mouth pressures (PIMAX) in healthy subjects--what is the lower limit of normal?

BACKGROUND: Maximal inspiratory mouth pressures are suitable for non-invasive evaluation of respiratory muscle function. Different studies on PIMAX give predicted normal values and their relation to anthropometric data. Due to a large inter-subject variation of PIMAX, predicted values, however, maximal inspiratory mouth pressures are not suitable to define the individual expected normal PIMAX. What is the lower limit of the normal range? METHODS: PIMAX has been prospectively measured in a representative sample of 504 healthy volunteers (248 males and 256 females) between 18 and 82 years of age with normal lung function. Age, height, weight, body mass index (BMI) and smoking status were recorded and incorporated stepwise in a multiple regression analysis to determine prediction equations. Lower limits of the normal range were defined as the fifth percentile of the residuals derived from the regression model. RESULTS: Mean values of PIMAX were 9.95 kPa for men and 7.43 kPa for women. Significant correlations were found with height, weight, BMI, FEV1, PEF and FVC (P<0.01). The strongest correlation appeared with sex and age (P<0.001). Smoking status and smoked pack-years were not independent predictors of inspiratory pressures. Lower limits of normal were 59% for women and 60% for men of the predicted PIMAX. CONCLUSIONS: In the interpretation of maximal inspiratory mouth pressures, normal values should represent the lower limit of the normal range derived from the regression model in order to avoid false pathological results. Prediction equations as well as lower limits of normal resulting from a study cohort of healthy 18-82-year-olds are given and are recommended to be used by pulmonary function laboratories in young and old patients.

Adolescent↗
PubMed2000

Gastric outlet obstruction and pulmonary infiltrate in a patient with Crohn's disease: successful treatment by Billroth-II-resection.

We present a 28-year-old women with a 3 yr history of duodenal ulcers. Following four treatment attempts to eradicate helicobacter pylori she was admitted because of gastric outlet obstruction and a weight loss of 20 kg within the last two years. Endoscopy and x-ray showed a circular inflammatory stenosis of the proximal duodenum extending over 8 cm. Additionally, chest x-ray showed a circumscript infiltrate in the third segment of the right lung. Mycobacterial infection could be excluded. Ileocolonoscopy and small intestinal follow-through beyond the duodenum were unremarkable, and Zollinger-Ellison-syndrome was ruled out. Bronchopulmonary histology showed intramucosal epithelioid-cell granulomas and bronchiolitis obliterans. Because the patient did not improve under conservative therapy a Billroth-II-resection was carried out. Histologically the resected specimen showed Crohn-like lesions. Postoperatively, severe peripheral arthritis was treated by steroids over 6 weeks. At follow-up the patient regained 20 kg and was free of symptoms without any medication. The pulmonary infiltrate had subsided almost completely. In summary, this extremely rare coincidence of isolated stenosing duodenal Crohn's disease and pulmonary involvement was successfully treated by Billroth-II-resection. This course of disease is compatible with the hypothesis that Crohn's disease may be maintained by antigens derived from ingested food.

Adult↗
PubMed2000

High frequency jet ventilation in interventional fiberoptic bronchoscopy.

UNLABELLED: High frequency jet ventilation (HFJV) is a well accepted method for securing ventilation in rigid and interventional bronchoscopy. We describe a technique of HFJV using a 14F nylon insufflation catheter placed in the trachea to support stent implantation or endobronchial balloon dilation in endobronchial stenoses with the flexible fiberscope. One hundred sixty-one cases were treated with either a metal wire stent (n = 105) or with balloon dilation (n = 56). In addition to HFJV, IV anesthesia was applied in 132 cases. Driving pressure was 1125-1275 mm Hg, frequency 80-100/min, and inspiratory:expiratory ratio of 1:2. Fraction of inspired oxygen ranged from 0.3-1.0. The effects on alveolar ventilation were assessed by using blood-gas analysis and continuous monitoring of transcutaneous oxygen and carbon dioxide tension (P(tc)CO(2)). Complications consisted of hypertension (n = 8), hypotension (n = 6), bronchospasm (n = 5), and hypoxia (n = 6). In 52% of the cases, mild hypercarbia (P(tc)CO2 50-60mm Hg) was observed. In two cases, a P(tc)CO(2) > 80 mm Hg resolved spontaneously when the patients returned to normal breathing after intermittent superimposed ventilation with a face mask. During placement of stents in the proximal trachea, the jet catheter had to be withdrawn, resulting in displacement of the catheter into the pharynx in one case, which was managed safely with the bronchoscope. In conclusion, HFJV achieves satisfactory operating conditions and provides adequate gas exchange for interventional bronchoscopic procedures with the fiberscope. IMPLICATIONS: Safe ventilation is desired when performing tracheobronchial stent implantation and balloon dilation with the fiberscope. High frequency jet ventilation, applied with a 14F insufflation catheter through the nasotracheal route, offers safe ventilatory support with minimal complications. This was evaluated in 161 procedures treating benign and malignant airway stenoses.

Adult↗
PubMed2000

Theophylline improves acute mountain sickness.

A randomized two-part study was conducted in order to determine the efficacy of theophylline in the treatment of acute mountain sickness during fast ascent to altitudes >2,500 m. Fourteen healthy male subjects participated in a randomized single-blind placebo-controlled crossover study carried out in a decompression chamber (simulated altitude 4,500 m). A second randomized single-blind, placebo-controlled study was conducted at a high-altitude research laboratory (3,454 m) and included 21 healthy male subjects. The study medication was either 375 mg oral slow-release theophylline (250 mg if <70 kg) or a matched placebo tablet taken twice daily. The acute mountain sickness score (AMSS) was assessed three times a day, beginning 18 h prior to altitude exposure and continuing for 18 h after altitude exposure. In addition, measurements of respiratory frequency, pulse rate, oxygen saturation and arterial blood gas levels were performed. Acute mountain sickness was significantly reduced by theophylline during the decompression chamber study (mean+/-SD 1.2+/-0.9) with placebo versus 3.6+/-0.8 with theophylline; p=0.03). During the high-altitude study, subjects with theophylline showed a significantly lower AMSS on arrival and after 18 h at altitude (0.6 versus 2.3, p=0.03). Oxygenation was improved in both parts of the study. In conclusion, oral slow-release theophylline improves acute mountain sickness.

Administration, Oral↗
PubMed1999

[Increased incidence of bronchial carcinomas. What is new in therapy and diagnosis?].

The increasing incidence and continuing poor prognosis of lung cancer make new therapeutic concepts necessary. For stage I and stage II disease, surgery remains the treatment of choice. In the case of inoperable patients, radiotherapy, used alone, may be a curative alternative. To improve the prognosis of stages II and III of non-small-cell lung cancer, multi-modal treatments such as neoadjuvant chemotherapy, combined chemo-/radiotherapy and post-operative irradiation are still being researched. Although present results indicate higher survival rates, these approaches have not yet become standard. The palliative options for stages III and IV have also clearly been expanded in recent years, so that late-stage lung cancer may yet respond to treatment. Such options are, in particular, invasive bronchoscopic procedures, such as treatment with the Nd-YAG laser, cryotherapy, dilatation and the implantation of stents, or intraluminal irradiation. The major and decisive measure, however, is still prevention which, for 85% of all lung cancer consists in the rejection of nicotine abuse. In the meantime, sensitive methods of early diagnosis have also become available. However, they are invasive and thus not suitable for large-scale screening, but are reserved for high-risk patients. Non-invasive methods are currently under development.

Carcinoma, Bronchogenic↗
PubMed1999

[Pulmonary trichomoniasis: diagnosis based on identification of irritation in bronchoalveolar lavage].

Bronchopulmonary infections caused by trichomonads have been reported mainly in patients with pre-existing pulmonary or debilitating disease (e.g. bronchial carcinoma, lung abscess, bronchiectasis). Pulmonary trichomoniasis is most often due to infection with Trichomonas tenax, usually regarded as a harmless commensal of the human mouth, and may rarely be caused by other trichomonas species. A 45 year old female presented with a dry cough, exertional dyspnoea and malaise. These symptoms persisted for 6 months regardless of anti-inflammatory and anti-obstructive inhalative therapy. Sarcoidosis of the lungs, diagnosed 20 years prior, had been asymptomatic since and there was no coexistent disease. Laboratory data revealed increased ACE-levels (90 IE/ml) and lung function showed bronchial hyperreactivity on histamine challenge. No other abnormalities were found (chest x-ray, bronchoscopy, lung function test, blood count and serum calcium). The diagnosis was based on the cytological identification of numerous trophozoites of T. tenax in the bronchoalveolar lavage. Therapy with oral metronidazol for 40 days led to complete recovery from symptoms and normalisation of ACE serum levels. The patient has remained well for 12 months since. The pathogenicity of oral trichomonads in the non-immunocompromised host remains uncertain. Our patient had no known medical risk factors by comparison with published cases. The case illustrates the clinical relevance of pulmonary trichomoniasis in an otherwise healthy person.

Animals↗
PubMed1999

Three-dimensional in vitro cocultivation of lung carcinoma cells with human bronchial organ culture as a model for bronchial carcinoma.

We describe the development of a three-dimensional in vitro organ culture model for bronchial carcinoma using bronchial mucosa organ cultures and three different human non-small cell lung cancer cell lines. During precultivation, bronchial fragments obtained as biopsies during routine bronchoscopy had regenerated a complete epithelial covering with a well-preserved organotypic architecture around a nucleus consisting of connective tissue. To create cocultures, different types of confrontation between tumor cells and organ cultures were applied. Histologic light microscopy and scanning electron microscopy were used in analysis. When tumor cells were confronted with completely epithelialized organ cultures, they showed a low incidence of attachment. When organ cultures were wounded before confrontation, tumor cells always attached to the wounded side and showed a progressive invasion into the stromal tissue. Measurements of the penetration depth of tumor cells into the organ cultures after different incubation times permitted the quantitative evaluation of invasion. Histologic studies revealed well-differentiated normal epithelium in spite of long culture periods. Histologic features of the tumors were those of an invasive undifferentiated carcinoma and showed marked similarities to the situation in vivo. The coculture model permits internal controls because it contains both normal human epithelium and human tumor cells in the same organotypic culture. Therefore it offers opportunities for various in vitro investigations on therapeutic and diagnostic modalities of lung cancer, as indicated in this paper by an example of photodynamic procedures with 5-aminolevulinic acid.

Aminolevulinic Acid↗
PubMed1998

Dissociation between high anti-PR3 titers (c-ANCA) and the clinical course of disease in a case of Wegener granulomatosis.

In May 1984 a 58-year-old woman presented with a broad spectrum of clinical symptoms including malaise, arthralgia, hemoptysis and dyspnea, proteinuria and hematuria and a vasculitic necrotizing rash. Bronchial biopsies revealed subglottic granulomatous lesions and renal biopsies showed necrosis, extracapillary proliferation and crest formation, confirming the diagnosis of Wegener granulomatosis. Positive c-ANCA and anti-proteinase 3 subfraction (anti-PR3) titers were first analysed in 1991. Clinical remission was achieved by standard immunosuppressive therapy and renal function was stabilised. Several minor relapses were treated with pulsed intravenous cyclophosphamide but the symptoms could not be completely controlled. Eight years after the onset of disease, a dramatic increase in anti-PR3 titers was observed (34438 U/ml, normal range < 10, ELISA), followed 3 months later by a clinically apparent relapse. Immunosuppressive therapy was reinstituted without clinical improvement. At this point plasmapheresis resulted in an amelioration of clinical symptoms as well as a reduction in anti-PR3 titers. Concomitant immunosuppressive therapy was administered with oral corticosteroids. Forty days later anti-PR3 titers increased, reaching 75000 U/ml twelve months later, however this time without associated clinical symptoms. During the following months the patient had a further transient deterioration of pulmonary and renal function due to secondary bacterial infection which was successfully treated with antibiotics. A nephritic sediment was not present during these episodes. Curiously, the anti-PR3 titers have remained excessively elevated for the last three years.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1998

Secretory cell types and cell proliferation of human bronchial epithelial cells in an organ-culture system.

To study the secretory products and the proliferation of cells of the human respiratory surface epithelium, we established a miniorgan-culture system of bronchial tissue. Biopsies of large airways were grown on agar-coated dishes immersed in a serum-enriched medium. As determined by light and transmission electron microscopy, between 1 and 3 weeks, the organ cultures were covered by a differentiated epithelium consisting of secretory, ciliated, and basal cells. Immunohistochemistry, using antibodies to mucin and lysozyme, and lectin histochemistry revealed both mucous and serous secretory cells in the epithelium. Cell proliferation was studied in situ using antibodies to proliferating cell nuclear antigen (PCNA) and Ki-67. Whereas at the time of explantation the proliferation was low (2.5+/-1.7% of the epithelial cells were PCNA-positive, 1.7+/-0.6 were Ki-67-positive), at 24 h of cultivation, 30.4+/-5.1% or 25.2+/-4.9% of the epithelial cells were labeled with antibodies to PCNA or Ki-67. After 7 days, the number of dividing cells was low again. The results show that the organ-culture system of human respiratory surface epithelium produces a differentiated epithelium that is useful in the study of secretory processes, differentiation, and proliferation.

Bronchi↗
PubMed1997

Does additional brachytherapy improve the effect of external irradiation? A prospective, randomized study in central lung tumors.

PURPOSE: Endobronchial brachytherapy has become more widely used to increase the total local dose of irradiation ("boost") applied for the treatment of lung cancer. Apart from treatment for local stenosis, endobronchial brachytherapy in combination with external irradiation (EI) has the potential to improve local tumor control and perhaps prolong survival, but the real benefit has not been proven yet. To evaluate the possible effects of external irradiation with an additional boost of high dose rate (HDR) brachytherapy, we conducted a prospective randomized study. METHODS AND MATERIALS: Design-two groups were compared: Group 1 was treated with external radiotherapy alone (planned dose 60 Gy); Group 2 received an additional boost of HDR brachytherapy of scheduled 4.8 Gy each (at 10 mm from the source axis) before and after external irradiation. Patients-98 patients with advanced inoperable lung cancer were included in the study, 42 in Group 1 and 56 in Group 2. Both groups were comparable with respect to age, sex, tumor stage, Karnofsky performance status (KPS), and histology. RESULTS: A mean total external irradiation dose of 50.5 +/- 14.1 Gy in Group 1 and 50 +/- 12.5 Gy in Group 2 was applied. Group 2 received an additional dose of 7.44 +/- 2.6 Gy (at 10 mm depth) through brachytherapy. The median survival time in both groups was comparable (28 weeks and 27 weeks, respectively). In patients with squamous cell carcinoma (68 patients) Group 2 showed an advantage in median survival with borderline significance (40 vs. 33 weeks, p = 0.09). Group 2 showed also a better local tumor control in all patients; patients with squamous cell carcinoma had a significantly longer period of local tumor control. Fatal hemoptysis was the cause of death in 6 (14.2%) patients in Group 1 and 11 (18.9%) in Group 2 (p = 0.53). CONCLUSIONS: High dose rate brachytherapy in patients with inoperable lung cancer increased local control in our randomized study when used in combination with external irradiation. Survival time was also longer, but with no clear statistical significance. This applied especially to patients with squamous cell carcinomas. There was no statistically significant difference in the incidence of fatal hemoptysis between the two groups.

Brachytherapy↗
PubMed1997

Pharmacokinetics of 5-aminolevulinic acid-induced protoporphyrin IX in skin and blood.

The fluorescence and photosensitivity of endogenously synthesized protoporphyrin IX (PPIX) is increasingly used for the diagnosis and treatment of malignant and certain non-malignant diseases. A selective accumulation of PPIX can be induced by application of 5-aminolevulinic acid (5-ALA), which is a precursor of PPIX in the cellular biosynthetic pathway of heme. The purpose of this study was to monitor the in vivo accumulation of PPIX in different locations of the skin after oral ingestion and to determine the pharmacokinetics of 5-ALA and PPIX in human blood plasma for various routes of application. At the same time we wanted to achieve an optimal treatment scheme but also study possible side-effects of 5-ALA administration. After oral application of 5-ALA in a concentration of 40 mg kg-1 body weight, the fluorescence intensities of PPIX in the skin showed maxima between 6.5 and 9.8 h depending on the location and decreased to values lower than 5% related to the maximum after a mean time of about 40 h. The measured absolute intensities of PPIX fluorescence varied strongly between different patients and different locations on one patient. In the plasma of blood samples, PPIX could be detected via its fluorescence for all studied routes of application with the exception of the ointment, where PPIX levels were below the detection limit of 1 microgram l-1. The highest mean concentration of 742 micrograms l-1 PPIX in the plasma was measured 6.7 h after oral application. For inhalation of 5-ALA, a mean maximum concentration of 12 micrograms l-1 could be detected 4.1 h after application, for intravesical instillation, the mean maximum concentration was found to be 1 microgram l-1 2.9 h after application. The kinetics of 5-ALA in the plasma peaked much earlier with a maximum concentration of 32 mg l-1 about 30 min. after oral administration. The 5-ALA levels did not exceed normal reference values after topical application. The results of our experiments suggest that for a systemic application of 5-ALA side-effects in sensitive patients cannot be excluded.

Aged↗