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Biomedical subjects

J Vogel

Publications and source records attributed to J Vogel.

At least 145 records · Page 8Linked to original sources
PubMed1994

[Differentiation of testicular diseases using dynamic MRT].

Sonography and colour-coded Doppler sonography are the methods of first choice in diagnosing tumors of the testes. The present study aimed at resolving whether dynamic MRT can improve diagnostic relevance in diseases of the testes compared with conventional spin echo images. The testes of 20 healthy volunteers and of 16 patients of the Department of Urology of the University of Bonn were examined by means of MR tomography. Within 12 hours after MR tomography the patients were surgically explored, biopsied and if necessary orchiectomised. Results obtained with the volunteers were uniform and well reproducible, independent of external influences. On comparing the maximal enhancement curves of the examined various testicular tumors with the standard values established by examining the healthy volunteers, the curves obtained with the malignant testicular tumors were always clearly above the chosen confidence range of 3 standard deviations so that malignancy diagnosis was easy. However, the degree of maximal enhancement did not enable us to arrive at a conclusion in respect of the tumor type or the degree of malignancy. The greatest enhancement occurred with the tumor of Sertoli's cell which could thus be clearly differentiated against the other malignant testicular tumors. Due to masking of the gadolinium effect by haemosiderin deposits, haemorrhagica in the tumor tissue should be excluded by means of T2-weighted spin echo sequences before following up a suspicion of malignant testicular tumor. Benign intratesticular changes could be safely separated from malignant findings by means of the maximal enhancement curve lying in the normal range or below the curve of the volunteers. As with other organs, dynamic MR tomography yields definitely more and better information than conventional MR tomography also in the diagnosis of testicular tumours. However, these "pros" do not offset the "cons" of high costs of such examinations, so that both conventional sonography and angiodynography remain the routine methods of choice. Indication for MR examination on suspicion of testicular tumour is therefore confined to cases where sonographic findings are clinically equivocal or technically unsatisfactory.

Adult↗
PubMed1993

[Diarrhea].

A 54-year-old man had recurrent watery diarrhea with up to 10 stools per day for 4 years. The initial evaluation including coloscopy did not disclose a pathologic finding. The symptoms subsided initially after four weeks. Three years later massive watery diarrhea recurred with up to fifteen daily stools. A reevaluation of the patient disclosed the diagnosis of collagen colitis in the colonic biopsy.

Colitis↗
PubMed1993

Pesticide residues in food in Switzerland.

Every year, official Swiss laboratories are involved in the analysis of about 8000 food commodities in the context of pesticide residue surveys. Between 90 to 100 different active ingredients are found normally in total foodstuffs analysed and more than 6% of the investigated samples have a contamination level exceeding the federal tolerance limits. No real improvement in what concerns the quality of food with respect to pesticide contamination has been observed these last years.

Dairy Products↗
PubMed1993

[Morphological classification and comparison of the different types of stromal nodules in benign prostatic hyperplasia].

The expression of immunohistochemical markers for cytoskeletal differentiation and that of neuroendocrine- and immunological cells showed in general the same tendency in the 4 types of prostatic stromal nodules: missing or low expression in immature-mesenchymal-, distinct augmentation in fibroblastic-, a maximum in fibro-muscular- and a slight decline in smooth-muscular nodules. These results are in agreement with developmental sequences, revealed by immunohistochemical investigations of fetal prostates, and seem to confirm the hypothesis that the four types of stromal nodules represent successive degrees of maturation, recapitulating ontogenetic processes.

Biomarkers↗
PubMed1993

Extravasation and transcytosis of liposomes in Kaposi's sarcoma-like dermal lesions of transgenic mice bearing the HIV tat gene.

Transgenic mice bearing the HIV tat gene develop dermal lesions resembling a common malignant tumor in AIDS, Kaposi's sarcoma (KS). To evaluate the permeability characteristics of these lesions and the therapeutic potential of drug-carrying liposomes, we have studied the localization of sterically stabilized liposomes, which show long circulation time in blood and increased accumulation in tumors. Liposomes encapsulating colloidal gold were injected intravenously into transgenic mice bearing KS lesions, and tissues were processed 24 hours later for both electron microscopy and for light microscopy with silver enhancement. Liposomes and silver marker were detected predominantly in the dermis surrounding the early and mature KS lesions, which were characterized by a proliferation of fibroblast-like spindle cells and abnormal blood vessels close to the epidermis. The silver-enhanced gold marker often surrounded vascular channels and scattered erythrocytes. As determined by electron microscopy, some spindle cells and macrophages had ingested intact liposomes. Transendothelial transport of liposomes was observed both through open channels between endothelial cells and also through endothelial cells lining intact vessels. Both extravasation and transcytosis of liposomes through irregular endothelium were much higher in KS lesions than in the adjacent normal skin. The high accumulation of sterically stabilized liposomes in KS lesions and their intracellular uptake by some spindle cells enhances their potential as carriers of chemotherapeutic agents against this neoplasm.

Animals↗
PubMed1992

[MR angiography of occlusive changes in the superior thoracic inlet veins].

We used MR angiography to assess the thoracic inlet veins in 5 normal volunteers and 14 patients with thrombosis of these veins. The results were compared with conventional venography and contrast-enhanced computed tomography (CT). The normal anatomy was readily depicted by MR angiography in all normal volunteers. Pathology was assessed correctly by MR angiography in all patients. Thrombosis of the internal jugular vein was seen on MR angiography in all cases whereas conventional venography failed to demonstrate this region adequately in 3 cases. The best overview of the thoracic inlet veins was achieved in the coronal plane; however, for detailed demonstration of pathology, imaging in additional planes was necessary. We conclude that MR angiography is a promising method for non-invasive assessment of thoracic veins.

Evaluation Studies as Topic↗
PubMed1992

Panniculus morbidus.

Eight patients with large panniculi are described where severe problems with hygiene, immobility, and chronic infection were caused by the lymphedematous, chronically infected pannus. Protracted nonsurgical management of the infected panniculus had failed in all 8 patients. Wedge resection without fat undermining removed diseased tissue. Infection and sepsis were eliminated and ambulation was restored in all patients. Formerly immobile patients were returned to normal activity. Significant self-induced weight loss was not observed in a 2-year follow-up period; weight gain, however, was not experienced. The primary anesthetic method was thoracic epidural reducing the requirements for general endotracheal anesthesia. The chronically infected pannus is a surgical problem deserving earlier recognition and resection.

Abdomen↗
PubMed1992

Induction of carcinoma at ureterosigmoid anastomosis--with and without faecal stream.

The induction of tumours at the site of uretero-intestinal anastomosis was investigated in Hannover: WISTAR rats. The rats were divided into 3 groups. In one group (n = 70) the ureter of the left kidney was implanted into the colon, using microsurgical techniques developed for humans. In 13% of the rats in this group benign tumours developed; in 16% malignant tumours occurred. In a second group (n = 76) the ureter was implanted into a rectal bladder; the faeces were excluded from the anastomosis by a descending colon anus praeter. In this group benign tumours developed in 17% and malignant tumours in 8%, all of them being situated at the site of the anastomosis. In a control group (n = 80) no colonic tumour could be identified.

Anastomosis, Surgical↗
PubMed1992

UV activation of human immunodeficiency virus gene expression in transgenic mice.

Human immunodeficiency virus (HIV) infection is associated with a clinical latency of as long as 10 years before the development of disease. One explanation for this delay is the requirement of cofactors such as other DNA or RNA viruses, cytokines critical for immune modulation, or environmental UV light. At least in tissue culture studies, these agents are capable of inducing HIV gene expression in cell lines which either harbor the entire viral genome or contain a reporter gene under the control of the viral long terminal repeat regulatory region. The role of these cofactors in terminating clinical latency and inducing disease has been difficult to ascertain because of the lack of an appropriate animal model. We now report that UV light can markedly induce HIV gene expression in transgenic mice carrying both the cis-acting (long terminal repeat) and trans-acting (the tat gene) elements which are essential for viral transactivation and replication in infected cells. Our finding may explain the clinical observations that cutaneous lesions in HIV-infected individuals are often seen in the sunlight exposed areas of the skin, including the face and neck.

Animals↗
PubMed1992

Sequence analysis of polymerase chain reaction amplified t(14;18) chromosomal breakpoints in formalin fixed, paraffin wax embedded follicular lymphoma.

AIMS: To determine whether junctional sequences of rearranged chromosomes can be amplified by use of the polymerase chain reaction (PCR) and whether direct sequence analysis of the PCR products is possible, using DNA from formalin fixed, paraffin wax embedded biopsy specimens. METHODS: DNA was extracted from paraffin wax embedded, formalin fixed lymphoma specimens, and junctional sequences of rearranged chromosomes were amplified by the PCR. The products were used as templates for asymmetrical PCR. Subsequently, direct sequence analysis was performed using the chain termination method. RESULTS: Formalin fixed, paraffin wax embedded biopsy specimens and PCR amplification could be used to determine the nucleotide sequences of junctional regions of rearranged chromosomes t(14;18) from patients with follicular lymphoma. CONCLUSION: The identification of junctional sequences of the translocation in follicular lymphoma provides a molecular "fingerprint" of t(14;18) of the lymphoma of an individual patient and can be used for the detection of clone specific DNA in any biopsy tissue obtained from the patient. The strategy used for rapid sequence analysis of PCR amplified DNA sequences will be useful in many areas of molecular pathology.

Base Sequence↗
PubMed1992

[Comparison of six peak flow meters for patients].

Five meters of six models of peak flowmeters have been checked by 40 measurements each in series with a pneumotachograph. There were no substantial differences between the five meters of one type, but the various models showed a different scatter, partly due to differences in the applied flow pattern. We prefer those peak flowmeters with less influence of the flow pattern.

Adult↗
PubMed1992

[Laparoscopic cholecystectomy versus mini-lap-cholecystectomy. Results of a prospective, randomized study].

Laparoscopic cholecystectomy (LCCE) was gaining acceptance rapidly, when several institutions could demonstrate the safety of this minimal invasive treatment modality. Nevertheless prospective randomised studies still are missing to prove the advantages of this new treatment modality in contrast to open cholecystectomy. 77 patients with symptomatic cholelithiasis were treated by LCCE (n = 40) or mini-lap CCE (n = 37) in a prospective, randomised study. As preliminary results, there were no differences in duration of anesthesia and operation time, perioperative complications or postoperative need for analgetics. Patients with LCCE had significant less postoperative pain, less restriction of total vital capacity and a shorter postoperative hospital stay as parameters of a diminished operative trauma.

Cholecystectomy↗
PubMed1992

[Use of multi-frequency oscillation method in the respiratory mechanics perimeter diagnosis].

Oscillatory resistance Rrs and reactance Xrs curves were measured in the frequency range 4-25 Hz at FRC-level and at the course of vital capacity manoeuvres. The 55 subjects investigated were separated into the three groups healthy subjects and patients with restrictive and obstructive lung diseases by means of the parameters airway resistance Raw and lung compliance CL estimated by body-plethysmography and esophageal pressure technique, respectively. In accordance with the Raw- and CL-values in each group the parameters Rrs and Xrs demonstrate at FRC-level a different frequency dependent behaviour. An enhancement of Raw in patients with COLD causes a drop of Rrs(f) and a displacement of the whole Xrs-curve into the negative direction. Conversely, the reduction of CL in patients with fibrosis leads to a significant decrease of Xrs-values at lower frequencies without marked changes in the Rrs-curves. An additional enhancement of Raw and a further reduction of CL can be induced by decrease and increase of lung volume VL in comparison with the FRC-level. These alterations can be detected also in the frequency dependent shape of the Rrs- and Xrs-curves. Because of this inverse influence of VL on Raw and CL the diagnostic differentiation between patients with mild obstructive and restrictive lung diseases can be improved by a simultaneous evaluation of the volume and frequency dependence of oscillatory parameters.

Airway Resistance↗