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Biomedical subjects

D Stahl

Publications and source records attributed to D Stahl.

At least 37 records · Page 2Linked to original sources
PubMed1997

Identification of IgG alloantibodies in patients with high-titer IgM cold agglutinins by serum/plasma affinity chromatography.

The detection of IgG alloantibodies in the presence of high-titer cold autoagglutinins (CAs) can be extremely difficult, especially under pressure of time when transfusion of red blood cells is urgently needed. Here we demonstrate that IgG alloantibodies in the presence of high-titer IgM CAs can be easily detected by quantitative IgG purification from serum or plasma by affinity chromatography. In comparison with the routinely used methods for IgG alloantibody identification, affinity chromatography shows better or identical results and is the method leading to results most rapidly.

Agglutinins↗
PubMed1996

Effects of cocaine on the EEG power spectrum of rats are significantly altered after its repeated administration: do they reflect sensitization phenomena?

It was previously shown that a moderate dose of cocaine (10 mg/kg i.p.) produces a pattern in the EEG power spectrum which indicates a preferential activation of dopamine D1-like receptors, namely a decrease of power in most of the frequency bands. In contrast, a large dose of cocaine (30 mg/kg i.p.) produces a decrease of power in most of the frequency bands as well, but a selective increase in the alpha-1 band, characteristic for an additional activation of dopamine D2-like receptors. In the present experiments, it was studied in rats, if in the course of sensitization, a shift from D1-like to additional D2-like receptor activation will occur or not. For this study, the animals were treated 10 times with cocaine (either 10 or 20 mg/kg) and, after a drug free interval of 4 days, tested with the same dose administered previously. Acute administration of 10 mg/kg of cocaine increased the locomotor activity slightly and its effect tended to be enhanced after repeated administration. Twenty mg/kg cocaine increased the locomotor activity more than the 10 mg/kg dose and its effect was significantly enhanced after repeated treatment. In addition, it was shown that the dose of 10 mg/kg of cocaine which activates D1- but not D2-like receptors is sufficient to elicit conditioned place preference. Ten mg/kg of cocaine produced a decrease of power in most of the frequency bands and this effect was slightly more pronounced after repeated treatment. Twenty mg/kg of cocaine acutely also produced a decrease in power in most of the frequency bands, but did not decrease the power in the alpha-1 band, being just at the threshold of activating D2-like receptors as well. Repeated administration led to a significant increase in power in the alpha-1 band and a less pronounced one in the alpha-2 band. This observation demonstrates that sensitization to cocaine can be manifest in the EEG and that after a certain dosage, a shift from an activation of D1-like dopamine receptors to an additional activation of D2-like receptors becomes obvious.

Analysis of Variance↗
PubMed1996

Repeat biopsy strategy in men with isolated prostatic intraepithelial neoplasia on prostate needle biopsy.

PURPOSE: Isolated high grade prostatic intraepithelial neoplasia on needle biopsy of the prostate is a strong predictor of malignancy on repeat biopsy. However, the optimal repeat biopsy technique for these patients has not been defined. MATERIALS AND METHODS: We reviewed the records of 66 men in whom isolated prostatic intraepithelial neoplasia was found on needle biopsy of the prostate. We evaluated the side and/or quadrant and grade of prostatic intraepithelial neoplasia on initial biopsy, and compared the findings to the location of cancer on repeat biopsy. RESULTS: Of 66 men 31 (47%) had cancer on repeat biopsy, with disease on the same side of the prostate as prostatic intraepithelial neoplasia in 20 (64%). The quadrant locations of prostatic intraepithelial neoplasia and cancer matched in 6 of 12 cases (50%). Low and high grade prostatic intraepithelial neoplasia predicted the side of cancer on repeat biopsy in 3 of 5 (60%) and 17 of 26 (65%) cases, respectively. CONCLUSIONS: Directing repeat biopsy solely to the side with prostatic intraepithelial neoplasia will miss cancer in approximately 35% of cases. The optimal repeat biopsy technique for patients with high grade prostatic intraepithelial neoplasia should include systematic biopsy of the prostate.

Aged↗
PubMed1996

Clinical and pathological features of hereditary prostate cancer.

PURPOSE: We determined whether the clinical and pathological features of hereditary prostate cancer differ from those of sporadic prostate cancer. MATERIALS AND METHODS: We compared the clinical and pathological features of radical prostatectomy specimens from 50 men with and 50 without a family history of prostate cancer who were matched for age and date of surgery. RESULTS: Median serum prostate specific antigen concentration was not significantly different in the 2 groups. Mean Gleason score plus or minus standard deviation in the 50 men with sporadic prostate cancer was 6.2 +/- 1 compared to 5.6 +/- 0.9 in those with hereditary disease (p = 0.008). Of the 50 hereditary and 50 sporadic prostate cancers 35 (70%) and 33 (66%), respectively, were pathologically organ confined (p = 0.69). Median percentage of carcinoma within the gland (determined morphometrically) in men with hereditary disease was 11.4 +/- 8.3 compared to 10.9 +/- 8.9 for those with sporadic cancer (p = 0.63). CONCLUSIONS: In our study population hereditary prostate cancers have significantly lower Gleason scores compared to sporadic carcinomas. Otherwise, there appear to be no substantial clinical or pathological differences.

Age of Onset↗
PubMed1996

Structure of antigens recognized by cold agglutinins.

At this time, three major groups of antigens recognized by cold agglutinins (CAs) are known: Iij antigens are defined by branched, linear, and branched and linear type 2 chains, respectively. They are protease- and sialidase-resistant. Whereas Ii antigens are developmentally regulated, j is expressed on newborn and adult erythrocytes in equal strength. The antigens of the Sia complex are biochemically related to the Iij antigens: they are sialylated type 2 chains. Consequently, they are protease resistant but sialidase-sensitive. Sia-l and Sia-b antigens are differentiation antigens, Sia-lb is not developmentally regulated. The structure of the Pr/Sa antigens is defined by the O-glycans of the glycophorins of the human red blood cell membrane. The immunodominant component is represented by N-acetyl-neuraminic acid. Therefore, Pr/Sa antigens are protease-sensitive. With one exception (Pra), the antigens of this complex are also sialidase-sensitive. They are not developmentally regulated.

Adult↗
PubMed1996

[Quality assurance in transfusion medicine: organization of a quality assurance system exemplified by the Heidelberg University Blood Bank].

The 'Pharmabetriebsverordnung' requires a quality assurance system for the manufacturing of blood products. The quality assurance system of the university blood bank at Heidelberg is founded on the components 'quality of structure', 'quality of process' and 'quality of result'. The internal quality standard, based on national law and national/international guidelines, is specified in written form for every aspect of structure, process and result by standard operating procedures (SOPs). The SOPs are the basis for the quality system manual and the laboratory reference books. The quality assurance system integrates a programme for carrying out internal quality audits as well as a concept for updating SOPs at regular intervals.

Blood Banks↗
PubMed1996

The phases of managed care: where does subacute care fit?

There are four phases of development in managed care based on their degree of market penetration: Phase I = up to 10%; Phase II = 11% to 30%; Phase III = 31% to 50%; and Phase IV = 50%+ of the market. Negotiation strategies vary according to the phase the market is in.

Continuity of Patient Care↗
PubMed1995

Morphometric analysis and clinical followup of isolated prostatic intraepithelial neoplasia in needle biopsy of the prostate.

PURPOSE: We evaluate the significance of grade and extent of isolated prostatic intraepithelial neoplasia in prostate needle biopsies as a predictor of cancer on repeat biopsy. MATERIALS AND METHODS: We reviewed our experience with 58 men 50 years or older who had isolated prostatic intraepithelial neoplasia on initial prostate needle biopsy during a prostate specific antigen (PSA) based screening trial for prostate cancer. All 58 men underwent repeat biopsy to follow the initial findings of prostatic intraepithelial neoplasia. We assessed the relationship of patient age, digital rectal examination, serum PSA concentration, PSA density, prostatic intraepithelial neoplasia grade, number of foci of neoplasia and linear extent of prostatic intraepithelial neoplasia in the initial biopsy specimen to the finding of cancer on the repeat biopsy. We also compared the cancer detection rate in the 58 men with and 427 without prostatic intraepithelial neoplasia in the same screening trial. RESULTS: Of 21 men with low grade and 37 with high grade prostatic intraepithelial neoplasia 4 (19%) and 19 (51%), respectively, had cancer on repeat biopsy (p < 0.02), compared to 82 of 427 (19%) without cancer or prostatic intraepithelial neoplasia on the initial biopsy. High grade prostatic intraepithelial neoplasia was a significant predictor of malignancy on repeat biopsy (p < 0.05). The number of foci of neoplasia and the linear extent of prostatic intraepithelial neoplasia on initial biopsy were not predictive of cancer on repeat biopsy. CONCLUSIONS: Our results demonstrate that the presence of high grade prostatic intraepithelial neoplasia is a strong predictor of prostate cancer in men with elevated serum PSA concentrations and they should be followed with repeat biopsy.

Aged↗
PubMed1995

[Establishing a quality assurance system in transfusion medicine exemplified by the Heidelberg University Blood Bank].

BACKGROUND: The 'Zweite Verordnung zur Anderung der Betriebsverordnung für pharmazeutische Unternehmer vom 13. Juli 1994' requires a quality assurance system for the manufacturing of blood products. METHODS: On the basis of national law and guidelines we worked out a concept for establishing a quality assurance system at a university blood bank and applied it to the university blood bank at Heidelberg. RESULTS: The quality assurance system of the university blood bank at Heidelberg is based on the components 'quality of structure', 'quality of process' and 'quality of result'. The internal standard is specified in written form for every aspect of structure, process and result by standard operating procedures (SOP). The SOP serve as a basis for the quality system manual and the laboratory reference books. The quality assurance system described here integrates a programme for carrying out internal quality audits as well as a concept for updating SOP at regular intervals. CONCLUSIONS: The concept underlying the quality assurance system of the university blood bank at Heidelberg allows continuous quality improvement in transfusion medicine; moreover, it offers the chance to integrate quality assurance in transfusion medicine in an interdisciplinary, patient-orientated, not only regional concept of quality assurance.

Blood Banks↗
PubMed1994

EMLA-induced analgesia inferior to lignocaine infiltration in curettage of common warts--a randomized study.

The analgesic effect of topical application of EMLA cream for the curettage verrucae vulgaris was compared to local infiltration with lignocaine in 89 patients. The main purpose of this randomized study was to evaluate the patients' overall impression of the treatment. All patients anaesthetized by lignocaine infiltration reported it as 'an acceptable procedure' compared to only 71% of the patients treated with EMLA. It cannot be recommended to use EMLA cream as local anaesthetic for curettage of verrucae vulgaris, presumably because the highly keratotic nature of the common warts does not allow sufficient penetration of epicutaneously applied EMLA.

Adolescent↗
PubMed1992

Analysis of epithelial and lymphoid phenotypic markers in relation to growth pattern of colorectal adenomas.

The relationship of villous to tubular adenomas is poorly understood and often difficult to characterize morphologically. A villous growth pattern in colorectal adenomas has been associated with a higher frequency of high-grade dysplasia. We compared phenotypic markers using immunoperoxidase techniques in paired samples of villous (75% to 100% villous) and pure tubular adenomas matched for size and degree of dysplasia, which were selected by review of 1,000 polyps from our files. The following monoclonal antibodies were used: CAM 5.2 and AE1/AE3 to cytokeratins; B18, D14, B7.1, and B7.8 to four distinct carcinoembryonic antigen epitopes; Leu-M1 and LN3 to HLA-DR antigen; LN2 to invariant chain class II major histocompatibility complex; LN1 and MB2 to B-cell markers; UCHL1 and MT1 to T-cell markers; Leu-7 to natural killer cells; Mac 387 to macrophages; S-100 to Langerhans-type cells; and a polyclonal antibody to secretory component. LN3 reactivity correlated with villous morphology and secretory component correlated with tubular morphology. Combined HLA-DR and secretory component expression discriminated between tubular and villous growth patterns in 12 of 15 pairs of adenomas (P less than .001). LN2 was expressed more frequently than LN3, but did not correlate with growth pattern. Neuroendocrine cells (Leu-7) were more frequent in tubular adenomas. Carcinoembryonic antigen epitopes did not relate to growth pattern. We did not confirm previously reported differences in cytokeratin expression. We concluded that among the markers tested, HLA-DR expression, which may have an immunologic basis, is most characteristic of colorectal adenomas that exhibit a villous growth pattern.

Adenoma↗
PubMed1992

Evolutionary relationships among sulfur- and iron-oxidizing eubacteria.

Some 37 reverse transcriptase, partial 16S rRNA sequences from sulfur- and/or iron-oxidizing eubacteria, including sequences from species of the genera Thiobacillus, Thiothrix, Thiomicrospira, Acidophilium, "Leptospirillum," Thiovulum, and Chlorobium, have been determined. In addition, 16S sequences from a number of unnamed sulfur- and/or iron-oxidizing bacteria from hydrothermal vent sites, from invertebrate-bacterial endosymbioses, and from various mineral recovery operations also have been determined. The majority of sequences place their bacterial donors in one or another of the subdivisions of the Proteobacteria. However, three unnamed facultatively thermophilic iron-oxidizing isolates, Alv, BC, and TH3, are affiliated with the gram-positive division. One H2S-oxidizer, from the genus Thiovulum, is affiliated with Campylobacter, Wolinella, and other genera in what appears to be a new subdivision of the Proteobacteria. Three "Leptospirillum"-helical vibrioid isolates, BU-1, LfLa, and Z-2, exhibit no clear phylum level affiliation at all, other than their strong relationship to each other. A picture is emerging of an evolutionary widespread capacity for sulfur and/or iron oxidation among the eubacteria.

Bacteria↗
PubMed1991

Topical metronidazole in the treatment of perioral dermatitis.

The twice-daily topical application of 1% metroindazole cream was compared with 250 mg oral tetracycline, taken twice daily, in the treatment of perioral dermatitis in a prospective, double-blind, double-dummy, randomized, multicenter trial. One hundred eight patients were treated for 8 weeks. At the end of this time the median number of papules in the metronidazole-treated group was reduced to 8% of the initial number, and the median number in the group treated with tetracycline was reduced to 0% of the initial number. Although both treatments were effective, oral tetracycline was significantly more effective than topical metronidazole.

Administration, Cutaneous↗
PubMed1990

The capsular polysaccharide is a major determinant of serum resistance in K-1-positive blood culture isolates of Escherichia coli.

Serum resistance is a major virulence factor of gram-negative bacteria, and K-1 polysaccharide has been shown to contribute to serum resistance in selected strains. To obtain further information about the role of K-1 in serum resistance and to find out whether loss of the ability to produce K-1 can induce loss of serum resistance, we studied the serum resistance of mutants derived from completely serum-resistant, K-1-positive blood culture isolates of Escherichia coli by selection for resistance to infection with K-1 specific bacteriophages. The amounts of K-1 polysaccharide produced by wild-type strains and mutants were measured, and outer membrane protein and lipopolysaccharide (LPS) patterns were analyzed. In each group of mutants, several highly serum-sensitive strains were found. All mutant strains expressed less K-1 than did the corresponding wild-type strains. Mutants that became highly serum sensitive always had less K-1 than did mutants with less-pronounced changes of serum resistance. A few mutants derived from different wild-type strains showed increased expression of outer membrane proteins with molecular weights of about 46,000 and 67,000. All of the wild-type strains examined had smooth-type LPS, and only two mutants had altered LPS structures; alterations of mutants in outer membrane proteins and LPS could not be correlated with alterations of serum resistance. The results indicate that for K-1-positive blood culture strains of E. coli, K-1 expression is a prerequisite for serum resistance, and loss of ability to synthesize K-1 leads to loss of serum resistance.

Antigens, Bacterial↗