PubMed Health⌕ Search

Biomedical subjects

C Seitz

Publications and source records attributed to C Seitz.

31 records · Page 2Linked to original sources

Outcome analysis of minimally invasive treatments for benign prostatic hyperplasia.

The armamentarium of minimally invasive treatment modalities for patients with benign prostatic hyperplasia has increased steadily during the past decade. The energy sources used range from microwaves and radiofrequency waves to high-intensity focused ultrasound, with laser vaporization/coagulation/resection and electrosurgical techniques. The large amount of data available allow some conclusions to be drawn concerning the present role of the "gold standard" TURP among the minimally invasive procedures. Although the subjective response after TURP and other minimally invasive procedures is comparable, improvements of flow and urodynamic parameters usually are more pronounced after TURP. Failure rates requiring reintervention (usually TURP) are considerable. Minimally invasive procedures lead to a shift of morbidity from the intraoperative phase, which is reduced (risk of bleeding, TUR syndrome, transfusion) to the postoperative phase. This period is characterized by prolonged urinary retention (ILC, VLAP), significant dysuria (VLAP, TUVP), and nycturia. Recent advances in electrosurgical techniques, such as band TURP loops that facilitate coagulation due to the longer contact time between the electrode and the tissue, have the potential to convert TURP into a less invasive procedure. Finally, high-energy TUMT seems to offer a truly minimally invasive treatment combining efficacy and the need for topical anesthesia only. However, due to a lack of homogeneity of criteria for patient recruitment, parameters of evaluation, and adequate follow-up; accurate guidelines for appropriate patient management have not been established yet.

Catheter Ablation↗

Combination and multivariate analysis of PSA-based parameters for prostate cancer prediction.

The aim of this study was to evaluate the ability of prostate-specific antigen (PSA)-based parameters including PSA density (PSAD), PSAD of the transition zone (PSA-TZ), percent free PSA, PSA velocity, and their combination to enhance the specificity of PSA for prostate cancer detection in men with serum PSA levels between 4 and 10 ng/mL. We evaluated prospectively 559 consecutive men referred for early detection of prostate cancer who had serum PSA levels between 4 and 10 ng/mL. All men underwent prostatic ultrasonography and sextant biopsy with two additional TZ biopsies. In all cases, if first biopsies were negative an additional set of biopsies was obtained within 6 weeks. The ability of PSAD, PSA-TZ, PSA velocity, percent free PSA, and their combination to improve the detection of prostate cancer was evaluated by univariate and multivariate analysis as well as receiver operating characteristic (ROC) curves. In this prospective study of 559 patients, 217 had prostate cancer and 342 had histologically confirmed benign prostatic hyperplasia. Multivariate analysis and ROC curves showed that PSA-TZ and percent free PSA (f/t PSA) were the most powerful and highly significant predictors of prostate cancer. Areas under the ROC curve (AUC) for PSA-TZ and percent free PSA were 0.827 and 0.778, respectively (p = .01). Combination of f/t PSA with PSA-TZ (AUC = 88.1%) significantly increased AUC as compared to each of the other parameters alone as well as their combination (p = .02). The next best combinations were PSA-TZ + PSAD, PSA-TZ + PSA, and f/t PSA + PSA. PSA-TZ followed by f/t PSA and PSAD were the most powerful predictors of prostate cancer in referred patients with a serum PSA between 4 and 10 ng/mL. f/t PSA + PSA-TZ was the most effective combination. When volume-independent PSA parameters were taken into consideration, f/t PSA + PSA clearly outperformed the other options.

Aged↗

Growth inhibitory and bactericidal efficacy of sera from Lyme borreliosis patients on B. burgdorferi strains.

Two B. afzelii strains EB1 and FEM1, classified in normal human sera (NHS) as serum-resistant, and an intermediate serum-sensitive B. burgdorferi s.s. strain 297, were tested in regard of their serum sensitivity in immune sera (IS) of patients at all stages of Lyme borreliosis by a growth inhibition assay (GIA). Fifty-four per cent (13/24) of the tested IS were GIA positive, while the sera of patients in stage III disease inhibited the growth more frequently than did the patients with sera of stage II or stage I disease. Growth inhibition was predominantly directed against strain FEM1 (12/24), less against strain EB1 (4/24) and strain 297 (2/24). A growth inhibiting effect on two strains was only detectable for two IS and merely one stage III serum inhibited all three strains. Positive results in the GIA required fresh serum and resulted in the killing of the borreliae. The detection of the deposited complement components C3 and C9 on the surfaces of the inhibited strains by means of immunofluorescence assays confirmed the role of complement. In Westernblot analyses of strain FEM1, it was striking that GIA-positive IS reacted 3- to 5-fold more often with proteins of molecular masses of 48.9-, 38.6-, 27.5-, 25-, 23.1- (OspC), 21.7-, and 16-kDa, than did GIA-negative IS. Furthermore, two proteins of approximately 20- and 31.2-kDa reacted exclusively with GIA-positive IS. Antibodies reacting with these proteins could play a role in the growth inhibition of NHS-resistant borrelial strains, OspC.

Antigens, Bacterial↗

Isolation and functional characterization of the mouse p75 TNF receptor promoter.

Tumor necrosis factor (TNF) is a pleiotropic cytokine that plays an important role in immunological and inflammatory responses. It exerts its biological effects via two distinct membrane receptors of apparent molecular weight of 55 (p55TNFR) and 75 kDa (p75TNFR), respectively. Most cell lines and primary tissues express both receptor types. While the p55TNFR gene is constitutively expressed at rather low levels, the transcription of p75TNFR is strongly modulated by a number of stimulatory agents. To characterize the mouse p75TNFR gene expression on a molecular level, we screened a mouse genomic library using the 5' end of the p75TNFR cDNA as a probe. A 6.3kb genomic clone containing about 6 kb of 5' flanking region and 300 bp of 3' sequence including the translational start site and the first exon was isolated and subcloned. Primer extension analysis revealed three transcriptional start sites located at -35, -39, and -564 bp upstream of the ATG-containing first exon. To determine whether the 5' flanking region exerts functional promoter activity, we generated deletion mutants fused to the luciferase reporter gene. Transfection of mouse fibroblasts (NIH3T3) with these constructs showed functional promoter activity of the isolated 5' region. By further sequence analysis of the 5' flanking region a number of putative DNA-binding sites for transcription factors, e.g., Sp1, CREB, Yi, YY1, and IFN gamma-responsive element, were identified.

3T3 Cells↗

The monoclonal antibody HCA2 recognises a broadly shared epitope on selected classical as well as several non-classical HLA class I molecules.

HCA2 is a widely used monoclonal antibody, thought to be highly selective for HLA-A and -G heavy chains. We demonstrate here that it also shows affinity to HLA-B73 and HLA-E molecules on intact cells. By comparing the differences in the amino acid (AA) sequences of several HLA class I alleles that are either recognised or not recognised by HCA2, a likely epitope of HCA2 has been deduced. It extends from position 76 to position 83 of the alpha1-domain. In intact cells, the solvent-exposed AA in positions 76 (Ala, Val, or Met), 80 (Asn or Thr) and 83 (Gly) are likely to constitute the recognition region. Inhibition experiments with peptides spanning the region of the alpha1-domain from position 74 to 85 of various HLA class I heavy chains prove that HCA2 recognizes a broadly shared epitope on HLA-E, -F and -G molecules as well as selected HLA-A, -B and -C antigens.

Amino Acid Sequence↗

Evaluation of the effect of 3 different diets on the bioavailability of 2 sustained release theophylline matrix tablets.

Food-induced changes on bioavailability of 2 sustained release theophylline matrix tablets, which uses an hydrophilic matrix of Carbopol 974P and lipid matrix of hydrogenated castor oil (Cutina HR) as sustaining agents, have been studied in 2 different groups of 12 healthy male volunteers. The study design was a 4 x 4 Latin square involving 12 subjects who received a single dose of the tablet while fasting or with a standarized normal, high fat or high fat/high protein meal. The results for both formulations showed no differences in t1/2 and MRT when the tablets were administered with any type of diet. No differences in tmax and AUC were found when the Carbopol matrix tablet was administered with any class of diet. Higher Cmax were obtained when the tablet was administered with any class of meal. The analysis of the ratio Cmax/AUC evidenced that changes in Cmax for normal and high fat diet were attributable to higher rate of absorption, probably due to a delay in gastric emptying, thus avoiding the rapid formation of the gel structure which controls the liberation of theophylline. Three subjects showed a probable bioadhesive behavior of the formulation in the fasted condition. The lipid matrix tablet showed a statistical significant delay in tmax comparing the fasted condition with the different diets. AUC, Cmax, and the ratio Cmax/AUC did not change when the tablet was administered with the normal diet. High fat and high fat/high protein diets produced higher AUC (31% and 40%, respectively) and Cmax (40% and 56%, respectively) than under fasting condition. The analysis of the ratio Cmax/AUC indicated that changes in Cmax were more probably due to changes in the amount absorbed. In conclusion, a sustained-release theophylline tablet formulated as a lipid matrix is affected by any meal with a high fat content, probably because of the increase of pancreatic and biliary secretions promoted by the meal that would affect the matrix itself. Normal diet showed this behavior but only as a nonsignificant trend. It seems appropiate to recommend to dose both formulations at least 2 hours before meal, or under consistent conditions of fasting or nonfasting state to assure reproducible absorption or clinical response.

Area Under Curve↗

[Color Doppler-guided compression of pseudoaneurysms after arterial puncture. Early and late results].

Sixteen pseudoaneurysms occurred after 1796 femoral arterial punctures for diagnostic coronary angiography and/or angioplasty, performed between 1. 1. 1993 and 25. 3. 1994. One additional patient with pseudoaneurysm had undergone a femoral arterial puncture at another hospital. Primary colour Doppler-directed compression of the pseudoaneurysm (15-minute compression followed by 10-minute compressions, as needed) was successful in 16 patients. There was one recurrence, after five days, which was successfully and lastingly treated by another compression. Primary thrombosing by compression of the pseudoaneurysm failed in only one patient, but after spontaneous thrombosis achieved by a compression bandage no flow was demonstrable on the following day. Clinical examination and/or colour Doppler sonography was performed on all patients a mean of 84 days (5 days to 6 months) after successful treatment: no recurrence was recorded. There were no significant early or late complications. These data indicate that colour Doppler-monitored compression of femoral-artery pseudoaneurysm can be considered the treatment of choice, with few exceptions, for this not rare complication of arterial catheterization.

Aneurysm, False↗

Influence of ethanol ingestion on tetracycline kinetics.

The effect of ethyl alcohol ingestion on tetracycline kinetics was studied in 9 healthy male volunteers. They received, on two separate occasions, 500 mg of tetracycline tablets given with water or with an alcoholic beverage. The antibiotic was assayed in plasma, using a HPLC method. Absorption and disposition parameters were calculated according to classical pharmacokinetic techniques for one compartment model. The significance of changes in pharmacokinetic parameters was determined by a multiway ANOVA test. In the present study, ingestion of alcohol caused significant increase of Cmax (from 9.317 to 12.362 micrograms/ml), and increase of AUC (from 62.65 to 94.28 micrograms/ml*h).

Absorption↗

Genetics of the quantitative Lp(a) lipoprotein trait. I. Relation of LP(a) glycoprotein phenotypes to Lp(a) lipoprotein concentrations in plasma.

The Lp(a) lipoprotein is a complex particle composed of a low density lipoprotein (LDL)-like lipoprotein and the disulfide bonded Lp(a) glycoprotein. The complex represents a quantitative genetic trait. SDS gel electrophoresis under reducing conditions of sera followed by immunoblotting with affinity-purified polyclonal anti-Lp(a) demonstrated inter- and intra-individual size heterogeneity of the glycoprotein with apparent Mr in the range 400-700kDa. According to their relative mobilities compared to apo B-100 the Lp(a) patterns were categorized into phenotypes F, B, S1, S2, S3 und S4 and into the respective double-band phenotypes. This size heterogeneity seems to be controlled by multiple alleles designated LpF, LpB, LpS1, LpS2, LpS3, LpS4 and a null allele (LpO) at a single locus. Phenotype frequencies observed in 441 unrelated subjects were in good agreement with those expected from the genetic hypothesis. Comparison of Lp(a) lipoprotein concentrations in the different phenotypes revealed a highly significant association of phenotypes B, S1 and S2 with high, and phenotypes S3 und S4 with intermediate Lp(a) concentrations. A third mode is represented by the null phenotype were no Lp(a) band is detected upon immunoblotting and Lp(a) lipoprotein is low or absent. We conclude that the same gene locus is involved in determining Lp(a) glycoprotein phenotype and Lp(a) lipoprotein concentrations in plasma. This major gene seems to be the Lp(a) glycoprotein structural gene locus.

Alleles↗

Intra-atrial malpositions of Silastic catheters in newborns.

The intra-atrial position of Silastic catheters placed in the center of the right atrium was assessed by two-dimensional echocardiography in 25 newborns. In 32% of the infants, the catheter tip was located in the patent foramen ovale, and in another 40% of the infants, the catheter tip was located close to the patent foramen ovale. This placement increases the risk of systemic air and fat embolism. Consequently, the tip of Silastic catheters should be placed just behind the confluence of the superior-inferior vena cava and the right atrium.

Cardiac Catheterization↗

Lp(a) glycoprotein phenotypes. Inheritance and relation to Lp(a)-lipoprotein concentrations in plasma.

The Lp(a) lipoprotein represents a quantitative genetic trait. It contains two different polypeptide chains, the Lp(a) glycoprotein and apo B-100. We have demonstrated the Lp(a) glycoprotein directly in human sera by sodium dodecyl sulfate-gel electrophoresis under reducing conditions after immunoblotting using anti-Lp(a) serum and have observed inter- and intraindividual size heterogeneity of the glycoprotein with apparent molecular weights ranging from approximately 400,000-700,000 D. According to their relative mobilities compared with apo B-100 Lp(a) patterns were categorized into phenotypes F (faster than apo B-100), B (similar to apo B-100), S1, S2, S3, and S4 (all slower than apo B-100), and into the respective double-band phenotypes. Results from neuraminidase treatment of isolated Lp(a) glycoprotein indicate that the phenotypic differences do not reside in the sialic acid moiety of the glycoprotein. Family studies are compatible with the concept that Lp(a) glycoprotein phenotypes are controlled by a series of autosomal alleles (Lp[a]F, Lp[a]B, Lp[a]S1, Lp[a]S2, Lp[a]S3, Lp[a]S4, and Lp[a]0) at a single locus. Comparison of Lp(a) plasma concentrations in different phenotypes revealed a highly significant association of phenotype with concentration. Phenotypes B, S1, and S2 are associated with high and phenotypes S3 and S4 with low Lp(a) concentrations. This suggests that the same gene locus is involved in determining Lp(a) glycoprotein phenotypes and Lp(a) lipoprotein concentrations in plasma and is the first indication for structural differences underlying the quantitative genetic Lp(a)-trait.

Apolipoproteins B↗