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Biomedical subjects

M Straub

Publications and source records attributed to M Straub.

At least 37 records · Page 2Linked to original sources
PubMed2000

Detection rate of histologically insignificant prostate cancer with systematic sextant biopsies and fine needle aspiration cytology.

PURPOSE: We evaluate the detection rate of insignificant prostate cancer and the rate of significant prostate cancer overlooked in the results of systematic sextant biopsy and fine needle aspiration biopsy of the prostate of asymptomatic men with serum prostate specific antigen concentrations less than 4.0 ng./ml. MATERIALS AND METHODS: We analyzed specimens from 133 consecutive patients with a mean age of 60 years undergoing cystoprostatectomy for bladder cancer. Six systematic biopsy specimens and 2 fine needle aspiration cytology samples were taken from the prostate immediately after cystoprostatectomy. The specimens were step sectioned and examined for prostate cancer. Insignificant prostate cancer was defined as any cancer with an aggregate volume 0.5 cm.3 or less. RESULTS: Incidental prostate cancer was found in 58 of the 133 patients (44%). Tumor volume was 0.5 cm.3 or less in 47 cases. Sextant biopsy detected 7 cancers, including 4 of 47 (9%) that were insignificant and 3 of 11 (27%) that were significant. Fine needle aspiration cytology also detected 7 cancers, including 3 (6%) and 4 (36%) that were insignificant and significant, respectively. CONCLUSIONS: Systematic sextant biopsy and fine needle aspiration cytology each diagnose prostate cancer in about 5% of asymptomatic men who have normal digital rectal examination and serum prostate specific antigen less than 4.0 ng./ml. However, many of the cancers thus detected are insignificant and most of the significant cancers are missed. Therefore, routine screening of such patients with sextant biopsy or aspiration cytology does not appear to be justified.

Adenocarcinoma↗
PubMed1999

[Effects of the K(+) channel blocker tedisamil on hemodynamics, myocardial ischemia and neurohumoral systems in patients with stable angina pectoris. A comparison with the beta blocker atenolol].

BACKGROUND: Clinical drawbacks of beta-blocker treatment in stable angina have motivated researchers to provide alternative heart rat lowering agents, such as tedisamil which additionally exerts anti-ischemic and antiarrhythmic effects by blockade of cellular repolarizing K(+) currents. METHODS AND RESULTS: 48 patients with stable angina pectoris were investigated (double-blind, randomized, parallel grouped) comparing the hemodynamic, anti-ischemic, metabolic and neurohumoral effects of tedisamil 100 mg b.i.d and atenolol 50 mg b.i.d. after a single dose and over 6 days of treatment. Tedisamil and atenolol produced a decrease in heart rate both at rest (day 1: -13.6 vs -15.4 bpm; p > 0.05; day 6: -14.8 vs -22.2 bpm; resp.; p > 0.05) and exercise (day 1: -9.1 vs -18.3 bpm; p = 0. 001; day 6: -12.0 vs -24.8 bpm, resp.; p = 0.001), while anginal threshold increased. Cardiac output decreased with tedisamil and atenolol at rest (day 1: -1.01 vs -1.19 l/min; p > 0.05; day 6: -0. 86 vs -1.10 l/min, resp.; p > 0.05) and exercise (day 1: -0.82 vs -1. 28 l/min; p > 0.05; day 6: -0.65 vs -2.68 l/min, resp.; p = 0.03), while stroke volume remained unchanged. Right atrial pressure changed during exercise only: It decreased with tedisamil (-1.7 mm Hg) and increased with atenolol (+3.7 mm Hg). Mean pulmonary capillary wedge pressures decreased at rest (-0.5 mm Hg) and exercise (-6.9 mm Hg) in the tedisamil group, but tended to increase with atenolol on day 6 (rest: +1.7; exercise: +3.7 mm Hg) (p = 0.03). Arterial pressure decreased under atenolol treatment only. Exercise-induced plasma norepinephrine levels were reduced by tedisamil (-93 pg/ml) but elevated by atenolol (+172 pg/ml) (p = 0. 001). As compared to atenolol, tedisamil produced a significant prolongation of QT (c) interval (+31 vs -8 ms) (p = 0.002) at initial values of 0.408 +/- 0.018 s with PQ and QRS remaining unaltered. CONCLUSIONS: In the present study, tedisamil (100 mg b.i.d. ) generated favorable hemodynamic, neurohumoral and anti-ischemic effects in patients with stable angina pectoris. The anti-ischemic efficacy of tedisamil, as measured by ST segment depression and angina threshold, is comparable to that of atenolol (50 mg b.i.d.).

Adrenergic beta-Antagonists↗
PubMed1999

5-aminolevulinic acid-induced fluorescence endoscopy applied at secondary transurethral resection after conventional resection of primary superficial bladder tumors.

OBJECTIVES: A prospective investigation was carried out to evaluate the use of 5-aminolevulinic acid (5-ALA)-induced fluorescence diagnosis with secondary transurethral resection (TUR). METHODS: Fifty patients underwent secondary TUR of the former resection area 6 weeks after conventional TUR for superficial bladder carcinoma. 5-ALA-induced fluorescence diagnosis was used in addition to standard white light endoscopy. All former resection areas were biopsied regardless of fluorescence findings. In addition, specific red fluorescent areas were resected, as were suspicious areas seen at white light endoscopy. RESULTS: One hundred thirty areas or tumors were resected. The sensitivity of fluorescence cystoscopy was 77.8% (95% confidence interval 52.4% to 93.6%). Residual tumors were found in the area of the former resection in 7 (14%) of 50 patients; 4 of these 7 were fluorescence negative and 3 were fluorescence positive. In an additional 7 patients (14%), exclusively fluorescing tumors not visible under white light could be detected outside the areas of former resection (n = 5, Stage pTaG1/2; n = 1, Stage pT1G1/2; n = 1, carcinoma in situ). CONCLUSIONS: Despite high sensitivity, fluorescence diagnosis at this early stage of control does not allow us to evaluate sufficiently the granulation tissue of necrotic areas after TUR without biopsy. The main advantage of the 5-ALA-induced fluorescence endoscopy is in the evaluation of untreated urothelium because of the easier detection of tumors not visible by conventional endoscopy.

Adult↗
PubMed1999

Clinical results of the transurethreal resection and evaluation of superficial bladder carcinomas by means of fluorescence diagnosis after intravesical instillation of 5-aminolevulinic acid.

BACKGROUND AND OBJECTIVE: The high recurrence rate of superficial bladder carcinomas requires new approaches in diagnosis and therapy. Particularly, an improvement in detection, resulting in better resection of flat lesions, which are poorly or not detectable under white light, is necessary. The effectiveness of fluorescence diagnosis for detection and transurethral resection of bladder carcinomas was investigated in a prospective study. MATERIALS AND METHODS: From 120 patients, 347 biopsies were taken or tumors resected with the aid of fluorescence from 5-aminolevulinic acid. Urothelial carcinomas and dysplasias were detected in 124 cases. RESULTS: Of the lesions, 119 were fluorescence positive (N = 74 pTaG1/2; N = 9 pT1G1/2; N = 11 pT1G3; N = 7 carcinoma in situ; N = 6 p > T1; N = 12 dysplasia II), and 5 were falsely negative (N = 3 pTaG1/2; N = 1 pT1G1/2; N = 1 dysplasia II). The sensitivity of the fluorescence diagnosis (96.0%) was significantly higher than the 67.5% sensitivity of white-light cystoscopy (P < 0.0001). Taking the data for primary or recurrent tumor resection and secondary resection separately, the sensitivity was 100% and 80%, respectively, and was significantly higher than that of white-light cystoscopy, which was 80.8% and 20 %, respectively (P < 0.0001 and P < 0.0008). The lower sensitivity of fluorescence diagnosis in secondary transurethral resection is attributed to the higher rate of false-negative findings in areas of former resection. CONCLUSIONS: The high rate of false-positive findings limits the correct interpretation of fluorescence findings. In spite of this, fluorescence diagnosis is superior to white-light cystoscopy in every case. By means of better detection of urothelial neoplasias and dysplasias, as well as more thorough and extensive resection under fluorescence control, it should be possible to reduce the recurrence rate of superficial bladder carcinomas.

Administration, Intravesical↗
PubMed1997

Use of DHEA in a patient with advanced prostate cancer: a case report and review.

Dehydroepiandrosterone (DHEA) is being evaluated in the basic science laboratories as a potential treatment for adenocarcinomas, with some initial promise for success. However DHEA can be metabolically converted to androgenic compounds, possessing unwanted side effects. A patient with advanced prostate cancer with progressive symptomatology was treated with DHEA after other treatment regimens failed. Many of his symptoms improved on DHEA therapy, but his cancer also flared dramatically during treatment. His previous hormonally unresponsive cancer subsequently responded transiently to third-line hormonal therapy with diethylstilbestrol (DES). Adrenal precursor molecules such as DHEA may have significant therapeutic benefits in a number of diseases of the elderly, however their utility may be limited by potential androgenic side effects including endocrine epithelial cell growth. The development of analogue compounds with less conversion to androgenic metabolites should be considered, as molecules such as DHEA are more widely tested and utilized clinically.

Aged↗
PubMed1997

AUT3, a serine/threonine kinase gene, is essential for autophagocytosis in Saccharomyces cerevisiae.

Autophagocytosis is a starvation-induced process, carrying proteins destined for degradation to the lysosome. In the yeast Saccharomyces cerevisiae, the autophagic process is visualized by the appearance of autophagic vesicles in the vacuoles of proteinase yscB-deficient strains during starvation. aut3-1 mutant cells which exhibit a block in the autophagic process have been isolated previously. By using the drastically reduced sporulation frequency of homozygous aut3-1 diploid cells, the AUT3 gene was cloned by complementation. The Aut3 protein consists of 897 amino acids. The amino-terminal part of the protein shows significant homologies to serine/threonine kinases. aut3 null mutant cells are fully viable on rich media but show a reduced survival rate upon starvation. They are unable to accumulate autophagic vesicles in the vacuole during starvation. Starvation-induced vacuolar protein breakdown is almost completely impaired in aut3-deficient cells. Vacuolar morphology and acidification are not influenced in aut3-deficient cells. Also, secretion of invertase, endocytic uptake of Lucifer Yellow, and vacuolar protein sorting appear wild type like in aut3-deficient cells, suggesting autophagocytosis as a novel route for the transport of proteins from the cytosol to the vacuole. By using a fusion of Aut3p with green-fluorescent protein, Aut3p was localized to the cytosol.

Amino Acid Sequence↗
PubMed1997

AUT1, a gene essential for autophagocytosis in the yeast Saccharomyces cerevisiae.

Autophagocytosis is a starvation-induced process responsible for transport of cytoplasmic proteins to the vacuole. In Saccharomyces cerevisiae, autophagy is characterized by the phenotypic appearance of autophagic vesicles inside the vacuole of strains deficient in proteinase yscB. The AUT1 gene, essential for autophagy, was isolated by complementation of the sporulation deficiency of a diploid aut1-1 mutant strain by a yeast genomic library and characterized. AUT1 is located on the right arm of chromosome XIV, 10 kb from the centromere, and encodes a protein of 310 amino acids, with an estimated molecular weight of 36 kDa. Cells carrying a chromosomal deletion of AUT1 are defective in the starvation-induced bulk flow transport of cytoplasmic proteins to the vacuole. aut1 null mutant strains are completely viable but show decreased survival rates during starvation. Homozygous delta aut1 diploid cells fail to sporulate. The selective cytoplasm-to-vacuole transport of aminopeptidase I is blocked in logarithmically growing and in starved delta autl cells. Deletion of the AUT1 gene had no obvious influence on secretion, fluid phase endocytosis, or vacuolar protein sorting. This supports the idea of autophagocytosis as being a novel route transporting proteins from the cytoplasm to the vacuole.

Amino Acid Sequence↗
PubMed1996

Colitis and lower abdominal mass by Actinomyces israelii in a patient with an IUD.

Abdominal actinomycosis is a rare disorder. The diagnosis is frequently missed preoperatively. We describe a patient who had had an intrauterine contraceptive device in situ for 5 years. She presented with a painful pelvicoabdominal mass, located between the uterus and rectum, and a colitis-like disease of the distal colon. Culture of the removed IUD demonstrated Actinomyces. She was intensively treated with intravenously penicillin for six weeks. Following this conservative treatment the abdominal tumor and the colitis-like symptoms totally disappeared. During two years follow-up she is free of symptoms and no signs of recurrence of the disease have been noticed. The case described here strongly underlines that Actinomyces infection should be born in mind in the differential diagnosis of a young female with an IUD, presenting with colitis, fever and an abdominal mass. Prolonged intravenously administered penicillin is warranted before surgery should be considered.

Actinomyces↗
PubMed1996

Studies on nutritional status in general surgery patients by clinical, anthropometric, and laboratory parameters.

We assessed the nutritional status of general surgery patients with and without cancer from a western European population in this prospective study. Anamnestic (weight development, abdominal complaints) and anthropometric (fat tissue measurements) data were collected on six groups of patients: cancer of the stomach (n = 13), pancreas (n = 13), colorectal (n = 23), breast (n = 12), and two control groups with benign diseases, ages 20-45 and 50-75 y. From these data, body mass index and ideal body weight were calculated. Concentrations of albumin, transferrin, retinol-binding protein, prealbumin, and creatinine height index were determined by biochemical tests. A weight loss of more than 10% was found in only 31% of gastric and 61% of pancreatic cancer patients. Significant values from anthropometric data were also found only in these groups. In biochemical tests, only the creatinine height index was reduced in all patients with pancreatic cancer. The remaining laboratory changes were so unspecific in all other parameters that no conclusions could be drawn as to the status of the patient's nutritional condition. For the evaluation of nutritional status, only relatively simple and inexpensive anamnestic and anthropometric measurements are necessary.

Adult↗
PubMed1994

Isolation of autophagocytosis mutants of Saccharomyces cerevisiae.

Protein degradation in the vacuole (lysosome) is an important event in cellular regulation. In yeast, as in mammalian cells, a major route of protein uptake for degradation into the vacuole (lysosome) has been found to be autophagocytosis. The discovery of this process in yeast enables the elucidation of its mechanisms via genetic and molecular biological investigations. Here we report the isolation of yeast mutants defective in autophagocytosis (aut mutants), using a rapid colony screening procedure.

Microscopy, Electron↗
PubMed1993

Tracing intracellular proteolytic pathways. Proteolysis of fatty acid synthase and other cytoplasmic proteins in the yeast Saccharomyces cerevisiae.

Yeast fatty acid synthase consists of two independent polypeptide strains, alpha and beta. The functional multienzyme complex, composed of six alpha- and six beta-subunits, is rather stable against proteolysis in vivo. Mutations in one of the subunits or deletion of one subunit lead to degradation of the nonmutated remaining fatty acid synthase protein. We show that the unassembled alpha-subunit of this enzyme is short-lived, and degradation depends on the presence of active cytoplasmic proteinase yscE, the yeast proteasome. The unassembled beta-subunit is degraded by a nonvacuolar proteolytic system under vegetative growth conditions. However, starvation of a vacuolar proteinase mutant strain, which lacks the alpha-subunit of fatty acid synthase, leads to appearance of the unassembled beta-subunit is isolated vacuoles. This indicates that the major vacuolar peptidases proteinase yscA and yscB are at least partly involved in degradation of the beta-subunit of fatty acid synthase. In a proteinase yscA and yscB double mutant strain wild type for fatty acid synthase both subunits of fatty acid synthase, alpha and beta, are detectable in vacuoles. In addition, under the same starvation conditions other cytoplasmic proteins are found in the vacuole of a proteinase yscA and yscB double mutant strain. The experiments in conjunction with the previous finding of the appearance of vesicles in vacuoles of starved cells (Simeon, A., van der Klei, I.J., Veenhuis, M., and Wolf, D. H. (1992) FEBS Lett. 301, 231-235) indicate that transport of these tested cytoplasmic proteins into the vacuole is an unselective bulk process induced by nutritional stress.

Cysteine Endopeptidases↗
PubMed1992

Parasitological and serological studies on the prevalence of Echinococcus multilocularis Leuckart, 1863 in red foxes (Vulpes vulpes Linnaeus, 1758) in Switzerland.

In the Canton of Zurich in Switzerland, 1,252 red foxes (Vulpes vulpes) were examined during 1990-1991 for intestinal stages of Echinococcus multilocularis using the mucosal smear technique. Special safety precautions were employed during examination. An average of 35% (432 foxes) were infected, mostly with low to medium numbers of gravid worms producing thick-shelled eggs. In the eleven districts of the Canton, prevalence rates varied between 13% and 57%. An average of 29% of the foxes had antibodies in serum or body fluid against a highly species-specific antigen of E. multilocularis (Em2-antigen). The fact that foxes with intestinal E. multilocularis infection have been found in all parts of the Canton of Zurich indicates a relatively high potential infection risk for humans, but apparently the risk is reduced by certain extrinsic or intrinsic factors which have yet to be determined.

Age Factors↗