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Biomedical subjects

R M Huber

Publications and source records attributed to R M Huber.

At least 73 records · Page 4Linked to original sources
PubMed1997

Impaired rapid mineralocorticoid action on free intracellular calcium in pseudohypoaldosteronism.

Earlier observations on impaired in vitro effects of aldosterone on lymphocytic sodium and potassium pointed to the involvement of a defective nongenomic rather than genomic effector in pseudohypoaldosteronism. In this study, we investigated nongenomic aldosterone action in five patients with pseudohypoaldosteronism with regard to a rapid increase of free intracellular calcium [Ca2+]i in cultured nasal epithelial cells, assumably reflecting calcium influx through calcium channels. Patients were defined by episodes of salt loss despite high plasma aldosterone and renin levels. Four unaffected members of the families and four independent subjects served as controls. Considering an aldosterone-induced increase of [Ca2+]i by at least 10 nm as positive response, only 12% of cells from patients were responsive compared with 25% in normal subjects (P < 0.05). In terms of absolute changes, mean increase of [Ca2+]i was 1.6 +/- 1.1 nm in the patients (range-1-4) and 9.5 +/- 2.7 nm (P < 0.025) in the controls (range 1-25). Basal [Ca2+]i was not different between both groups (167 +/- 5 vs. 169 +/- 8 nm, mean +/- SE). These findings show an impaired nongenomic mineralocorticoid effector in patients with pseudohypoaldosteronism, which is in line with a defective sodium channel as shown recently by molecular cloning, and also with the fact that the classical, genomic intracellular receptor is structurally normal in these patients.

Adult↗
PubMed1996

Liver-directed gene therapy: a retroviral vector with a complete LTR and the ApoE enhancer-alpha 1-antitrypsin promoter dramatically increases expression of human alpha 1-antitrypsin in vivo.

Hepatic gene therapy could improve the treatment of many inherited disorders. Although retroviral vectors result in long-term expression in hepatocytes in vivo, their low level of expression currently precludes most clinical applications. Four copies of the liver-specific apolipoprotein E (ApoE) enhancer were placed upstream of the human alpha 1-antitrypsin (hAAT) promoter in either orientation into a retroviral vector with a complete long terminal repeat (LTR) and the hAAT cDNA to generate ApoE(+)hAAT-LTR and ApoE(-)hAAT-LTR. In addition, the ApoAI promoter was placed upstream of the hAAT cDNA in a similar retroviral vector backbone. Amphotropic retroviral vectors were transferred into regenerating rat liver cells in vivo by intraportal injection. ApoE(-)hAAT-LTR and ApoE(+)hAAT-LTR led to average hAAT levels of 5 micrograms/ml (0.5% of normal levels of a very abundant protein), and 2.5 micrograms/ml, respectively, which was stable for at least 10 months after transduction. This level of serum hAAT was > 25-fold higher than what was observed from the ApoAI promoter used in this study. Serum levels of hAAT were > 15-fold higher than what was observed from retroviral vectors containing the hAAT cDNA that were analyzed previously by this lab. In some cases, improved expression was due to the promoter chosen. In other cases, the increase in expression was primarily due to the higher titers obtained by using a retroviral backbone with an intact LTR as opposed to a vector with a deletion in the LTR. The increased expression levels observed from this enhancer/promoter combination in an intact retroviral backbone may enable one to achieve therapeutic levels of clinically important genes from a retroviral vector in liver cells of animals.

Animals↗
PubMed1996

Bilateral bronchial balloon dilatation and Strecker stent implantation in a ventilated child with malignant carinal stenosis.

Tracheobronchial endoluminal reconstruction and stenting has become a valuable palliative tool in adults with intrathoracic tumors compromising the airways. Tracheobronchial balloon dilatation has been recently used in children and even neonates. We report a case of severe airway obstruction requiring emergency intubation and artificial ventilation in a 5-year-old child with intrathoracic recurrence of a rhabdomyosarcoma. Endoscopic balloon dilatation through the endotracheal tube with subsequent implantation of a non self-expanding metal mesh stent was used successfully, allowing extubation and discharge of the child from ICU.

Airway Obstruction↗
PubMed1996

Inhalation of 5-aminolevulinic acid: a new technique for fluorescence detection of early stage lung cancer.

Topical application of 5-aminolevulinic acid (5-ALA), with subsequent synthesis of protoporphyrin IX (PPIX), is a novel outstanding procedure for photodynamic treatment. So far, clinical experience has been reported with creams containing 5-ALA for the therapy of skin cancer, oral application for the treatment of gastrointestinal disease and intravesical instillation of 5-ALA solutions for fluorescence detection of superficial bladder cancer. Inhalation of 5-ALA for the staining of bronchial malignancies is a preferred method in clinical pulmonology. Since no adverse reaction was observed in lung function in a canine following inhalation of 5-ALA in increasing concentrations, clinical applications were performed. Seven patients with positive or suspicious sputum cytology, but negative white light bronchoscopy, received 5-10 wt.% 5-ALA in NaCl solution by means of a medical nebulizer. No side effects were observed during and after 5-ALA inhalation. After a period of 3 h, patients underwent fluorescence bronchoscopy using violet light for fluorescence excitation and an optical multichannel analyzer for fluorescence detection in situ. The results showed fluorescence spectra which could be related to PPIX induced by 5-ALA in the bronchial mucosa. The fluorescence intensity was sufficiently high for video imaging using a target integrating color CCD camera adapted to the flexible bronchoscope. Carcinoma in situ, as well as dysplasias, showed a clear positive fluorescence. A correlation of fluorescence contrast with histology on 30 biopsies revealed a high sensitivity, but a specificity below 50%. Improvements in light and drug dosimetry will form the basis for further clinical trials.

Administration, Inhalation↗
PubMed1996

Stent flexibility: an essential feature in the treatment of dynamic airway collapse.

Implantation of endobronchial stents for treatment of dynamic airway collapse represents a suitable therapeutic option to alleviate distressing symptoms. We report the case of a 43 year old patient suffering from progressive respiratory distress 2 weeks after insertion of a balloon-expandable radial noncompliant Palmaz stent in an unstable segment of the left main bronchus, with the aim of preventing symptomatic airway collapse. Bronchial instability had developed following sleeve resection of the right lung due to adenoid cystic carcinoma. Explanation revealed compression and deformation of the stent. Peak expiratory flow (PEF) had declined a low of 1.38 L.s-1 (forced expiratory volume in one second (FEV1) 1.02 L). With placement of a Strecker stent, having the ability to re-expand within certain limits, bronchial collapse could be avoided and marked clinical improvement as well as expiratory flow increase was noted (PEF 7.10 L.s-1; FEV1 = 2.03 L). At 13 months follow-up, clinical status was unchanged. A decline in forced expiratory flow (PEF 5.96 L.s-1; FEV1 1.69 L), however, indicated a possible change in the structural integrity of the Strecker stent. We conclude that physical properties of endobronchial stents may be crucial for good functional results in major airway collapse. Stiff prostheses, when compressed, can induce severe airway obstruction.

Adult↗
PubMed1995

Effect of growth hormone (hGH) replacement therapy on physical work capacity and cardiac and pulmonary function in patients with hGH deficiency acquired in adulthood.

The effects of 6 months of replacement therapy with recombinant human GH (hGH) on physical work capacity and cardiac structure and function were investigated in 20 patients with hGH deficiency of adult onset in a double blind, placebo-controlled trial. The GH dose of 12.5 micrograms/kg BW was self-administered daily sc. Oxygen consumption (VO2), CO2 production, and ventilatory volumes were measured during exercise on a bicycle spiroergometer. M-Mode echocardiography was performed using standard techniques. The VO2 max data, expressed per kg BW (mL/min.kg BW) showed a significant increase from 23.2 +/- 2.4 to 30.0 +/- 2.3 (P < 0.01) in the hGH-treated group, whereas the VO2 max data, expressed per lean body mass (milliliters per min/kg lean body mass) did not change significantly in either group. Maximal O2 pulse (milliliters per beat) increased significantly from 15.2 +/- 5.6 to 19.6 +/- 3.3 mL/beat (P < 0.01), but remained constant in the placebo group. The maximal power output (watts +/- SE) increased significantly (P < 0.01) from 192.5 +/- 13.5 to 227.5 +/- 11.5 in the hGH-treated group, but remained constant in the placebo group. Cardiac structure (left ventricular posterior wall, interventricular septum thickness, left ventricular mass, left ventricular end-systolic dimension, and left ventricular end-diastolic dimension) as well as echocardiographically assessed cardiac function did not change significantly after 6 months of treatment in either group. We conclude that hGH replacement in hGH-deficient adults improves oxygen uptake and exercise capacity. These improvements in pulmonary parameters might be due to an increase in respiratory muscle strength and partly to the changes in muscle volume per se observed during hGH replacement therapy. Furthermore, an increased cardiac output might contribute to the improvement in exercise performance during hGH treatment. According to our data, hGH replacement therapy leads to an improvement of exercise capacity and maximal oxygen uptake, but has no significant effect on cardiac structure.

Adult↗
PubMed1995

Palliative endobronchial brachytherapy for central lung tumors. A prospective, randomized comparison of two fractionation schedules.

AIM OF THE STUDY: Remote high dose rate brachytherapy is an effective local treatment modality for central lung tumors and has the potential to improve survival time. Optimal dose and fractionation schemes have not been identified yet. We conducted a prospective randomized study to compare two treatment schedules in terms of survival time, local tumor control, and possible complications. DESIGN: Group 1 received 4 brachytherapies with a dose of 3.8 Gy (at a 10-mm depth) on a weekly basis, and group 2 received 2 treatments with 7.2 Gy (at a 10-mm depth) at a 3-week interval. At a depth of 5 mm, the calculated doses would be 8 and 15 Gy. This study is still ongoing. Here we report interim results. PATIENTS: Ninety-three patients with advanced cancer were included in the study; 44 were in group 1 and 49, in group 2. Both groups were comparable regarding age, sex, tumor stage, Karnofsky performance status, and histologic findings. INTERVENTIONS: A mean total irradiation dose of 13.4 +/- 5.2 Gy for group 1 and 13.7 +/- 4.4 for group 2 were applied (calculated at 10 mm from the source axis, equivalent to 27.9 Gy in group 1 and 28.5 Gy in group 2 at a 5-mm depth). RESULTS: The 1-year survival rate was 11.4% in group 1 and 20.4% in group 2. No significant difference in survival time was found, but mean survival was longer in group 2 (49 weeks) than in group 1 (26 weeks). Local control after 3 months was comparable in both groups. Fatal hemoptysis occurred at a similar rate in group 1 (22.2%) and in group 2 (21.1%). CONCLUSION: High-dose rate brachytherapy with 2 x 7.2 Gy with a 3-week interval is equivalent to a 4 x 3.8-Gy regimen on a weekly basis. The shorter treatment schedule is more convenient for patients, does not cause more side effects, and provides an equal local tumor control.

Adult↗
PubMed1994

[Esophagomediastinal fistulae as a rare complication of tuberculosis in an HIV-infected patient].

A 57-year-old man with an HIV infection, diagnosed a year ago, complained of fever and cough. The haemoglobin level was 7.5 g/dl, white cell count 3800/microliters, T-helper cell count 60/microliters and the CD4-CD8 ratio 0.1. Erythrocyte sedimentation rate was raised to 21/39 mm. Bacteriological tests were at first negative. The chest radiograph showed slight widening of the upper mediastinum which further increased over the next 10 days, at which time it also revealed a shadow in the right upper lobe. Computed tomography suggested necrotizing mediastinal lymph-nodes. Treatment was begun with rifampicin (600 mg daily) ethambutol (1.2 g daily), pyrazinamide (1.5 g daily) and ciprofloxacin (500 mg twice daily). Oesophagoduodenoscopy, performed after 3 weeks, revealed several fistulae which, after ingestion of contrast medium, were demonstrated to communicate with the mediastinum, presumably as a result of lymph-node liquefaction. Mycobacterium tuberculosis was demonstrated in gastric juice, sputum and stool only after tuberculostatic drugs had been started.

AIDS-Related Opportunistic Infections↗
PubMed1992

[Value of dacryocystography in diagnosis of lacrimal duct diseases].

The paper compares the preoperative localization of stenosis in the lacrimal passage after digital dacryocystography with the operative findings in 23 eyes of 22 patients in the years 1988 to 1991 at the Munich University Eye Hospital. In a very high percentage (95.6%) there is a positive correlation. The discussion shows the advantages of the method and includes a review of relevant literature.

Adolescent↗
PubMed1991

Growth-hormone releasing hormone in a bronchial carcinoid.

The case is reported of a 43-year-old patient with a peripherally located bronchial carcinoid tumor containing large amounts of immunoreactive and bioactive growth-hormone releasing hormone (GHRH). Because no GHRH was found in the peripheral circulation, there was no quantitative or qualitative derangement of growth-hormone secretion. The tumor was excised completely by thoracotomy.

Adult↗
PubMed1990

[Photodynamic therapy of bronchial cancer].

Photodynamic therapy (PDT) with porphyrin derivatives (haematoporphyrin and dihaematoporphyrin äther/ester) and laser light of the wavelength 640 nm, is a new procedure for the treatment of carcinomas. This form of therapy is selective, can be applied through the bronchoscope, and is aimed at accomplishing curative elimination of central tumours of the lung. To date, we have successfully applied PDT in four selected patients. Our first patient was treated in April, 1987. The irradiation modalities and the clinical course are described.

Adenocarcinoma↗
PubMed1990

[Long-term follow-up of 52 endoluminal irradiated patients with central lung tumors].

The results of a prospective follow-up study comprising 52 patients with central tumours of the lung submitted to endoluminal irradiation are reported. Additional external irradiation was possible in 30 patients (group A), but not in 22 patients (group B). Satisfactory immediate results were observed, together with a one-year survival rate of 39.3% (group A) and 12.5% (group B).

Aged↗
PubMed1989

Bronchoscopic photodynamic therapy of bronchial carcinoma.

Photodynamic therapy with photosensitizers is a new method of treating malignant tumors. In the area of bronchoscopy it is employed for the selective therapy of early carcinomas at central localizations. We report on our first attempts at treatment with hematoporphyrin derivative in an inoperable patient. The modalities of irradiation and the recurrence-free progress of, to date, 2.5 years, are described.

Bronchoscopy↗
PubMed1989

Tumors of the bronchi: role of evaluation with CT.

Computed tomography (CT) was performed in 142 patients thought to have an endobronchial tumor based on clinical or radiologic grounds. In 121 patients an endobronchial mass was confirmed at bronchoscopy with biopsy or at surgery. The CT scans were evaluated independently by two experienced observers (A and B). For statistical purposes the result in each single bronchus from the level of the trachea to the segmental bronchi was considered separately. A total of 361 abnormal and 1,413 normal bronchi were confirmed with bronchoscopy or surgery. Observers A and B identified 100% and 99%, respectively, of the abnormal bronchi and 97% and 96%, respectively, of the normal bronchi on CT scans. For the standard CT examination (8-mm-thick sections) a sensitivity of 94% (observer A) or 91% (observer B) and a specificity of 99% (observers A and B) were found in the diagnosis of a normal or narrowed bronchial lumen. CT proved to be a reliable method for demonstrating tumor lesions of the bronchi.

Bronchial Neoplasms↗
PubMed1989

[Digital subtraction phlebography of the orbit. Technic and diagnostic value].

Orbital venography in the diagnostic assessment of vascular and extravascular expanding lesions of the orbit has been almost abandoned during the last decade due to the rapid development of computed tomography, ultrasound echography, and magnetic resonance imaging. Digital subtraction angiography (DSA) is a new angiographic modality that has recently replaced conventional techniques. DSA saves time and contrast media while facilitating vascular imaging and processing; this decreases the invasiveness of angiographic procedures. We describe the technique used for orbital phlebography via puncture of a frontal vein and injection of a contrast medium during manual compression of the infraorbital veins. We present the history and diagnostic findings of a 21-year-old man suffering from an orbital varix and discuss the diagnostic value of digital subtraction phlebography. In summary, the application of digital subtraction techniques is recommended as an additional diagnostic modality, particularly when impaired venous perfusion of the orbit is suspected.

Adult↗