Biomedical subjects

S Scholz

Publications and source records attributed to S Scholz.

At least 37 records · Page 2Linked to original sources

PubMed2001

Identification of a novel HLA-B*2722 allele from a Filipino cell.

We present the novel HLA-allele B*2722 amplified and sequenced from a Filipino individual. This DNA was included several times in the International Cell Exchange, UCLA, and typed at the time as B*27 or B*2706 by the majority of the participating laboratories. The second HLA-B allele of this person is B*3802. B*2704/06 or B*2704/06/10 were suggested by approximately one-third of the laboratories. As we were investigating the intron 3 sequences of B*27 alleles, we also sequenced exon 4 of this Filipino DNA and found a single nucleotide exchange in exon 4 (pos. 704) which was not in concordance with the previous B*2706 typing. Our sequencing results showed that the coding sequence of B*2722 is identical to B*2706 in exon 1, 2 and 3. In exon 4 the B*2722 sequence is identical to B*2704. HLA-B*2704 differs from B*2706 in one base at position 704, a G in B*2704 and a C in B*2706, respectively.

Alleles↗

PubMed2001

Linkage disequilibria between HLA-B, C1_4_1, MICA and MICB.

The polymorphisms of MICA exon 5 (5 alleles), MICB intron 1 (13 alleles), C1_4_1 (6 alleles), HLA-B (29 alleles) and HLA-A (15 alleles) were investigated in a healthy German population. Sequencing was performed for the MICB alleles CA14, CA15, CA17, CA23 and CA26 isolated from different cell lines. Variation to the published sequence was observed for CA14, CA15 and for CA17. At the C1_4_1 locus a new allele (CAAA)9 was identified and confirmed by sequencing. Linkage disequilibria were investigated for two-point- and three-point-haplotypes. Although the average relative delta value correlates loosely with the physical distance from HLA-B to MICB: HLA-B-C1_4_1>HLA-B-MICA>HLA-B-MICB, there are several exceptions to this rule. Analyzing three-point-haplotypes for the segment MICB to HLA-A a wide variation of linkage disequilibria for some of the classical HLA-A, B haplotypes has been observed. While the HLA-A1, B8 haplotype displays strong relative delta values over the entire distance from HLA-A to MICB, other haplotypes have linkage disequilibria only in a limited region.

Base Sequence↗

PubMed2001

Controlled hypercapnia during one-lung ventilation in patients undergoing pulmonary resection.

BACKGROUND: In a pilot study, the haemodynamic and gas exchange effects of acute hypercapoia during one-lung ventilation in thoracotomy patients were investigated. The effects of normocapnic one-lung ventilation (OLV-N) on haemodynamics and pulmonary gas exchange were compared with those of hypercapnic one-lung ventilation (OLV-H) in 14 patients undergoing pulmonary lobectomy. METHODS: Hypercapnia was induced by decreasing tidal volume until PaCO2 increased to 8-9 kPa. During OLV, minute ventilation was reduced from 8.8+/-1.7 to 4.2+/-0.7 l min(-1). RESULTS: Cardiac index (from 3.3+/-0.6 to 3.9+/-0.6 l min(-1), P<0.01) and pulmonary vascular resistance index (from 245+/-96 to 347+/-125 dyn s cm(-5) m(-2), P<0.05) increased during OLV-H, whereas systemic vascular resistance index decreased from 1952+/-403 to 1636+/-361 dyn s cm(-5) m(-2) (P<0.01). Pulmonary oxygenation remained unchanged. CONCLUSIONS: All patients had an uneventful course during OLV-H. The determinants of pulmonary oxygenation during hypercapnic one-lung ventilation remain to be further elucidated.

Blood Gas Analysis↗

PubMed2001

Subcutaneous curettage vs. injection of botulinum toxin A for treatment of axillary hyperhidrosis.

BACKGROUND: Axillary hyperhidrosis is a functional non-inflammatory abnormality of the eccrine sweat glands. The cause of genuine hyperhidrosis is unknown and, therefore, no specific corrective therapy is available and conservative treatment often fails. Subcutaneous sweat gland curettage of the axillae is one of the proven surgical modalities. Local injection of botulinum toxin A (BT-A) is a promising new conservative approach. OBJECTIVE: The purpose of this study was to compare the efficacy of subcutaneous curettage vs. injection of BT-A in axillary hyperhidrosis. METHODS: A total of 113 patients (36.3% males, 63.7% females) suffering from genuine axillary hyperhidrosis were treated by either subcutaneous curettage (n = 90) or local injection of BT-A (n = 23). Median follow-up period was 23.5 months. Questionnaires were handed out to patients for a subjective assessment of symptoms before treatment, 6 months after the procedure, and at the time of last follow-up. The patients were asked to rate the amount of axillary sweating based on a score ranging from 1 (no axillary secretion) to 6 (maximum axillary secretion). The subjective scores of sweating at rest, at high temperatures, under physical stress, under emotional stress and after spicy meals were assessed. RESULTS: The patients' subjective assessments of the overall outcome after subcutaneous curettage were 'very good' in 36.4%, 'good' in 29.9% and 'satisfactory' in 16.9%. The subjective score of axillary sweating at rest was reduced to 40.0% after 6 months, and finally to 45.7% at the end of follow-up (median: 28.2 months). Patients treated by BT-A injection assessed outcome as 'very good' in 39.1%, 'good' in 21.7% and 'satisfactory' in 8.7%. Sweating at rest was reduced to 48.5% after 6 months, and finally to 68.8% at the end of follow-up (median: 16.1 months). The mean duration of the antiperspiration effect of BT-A was 7.6 months (median: 7 months), but there were two cases of long durations, i.e. 14 and 18 months. CONCLUSIONS: Subcutaneous curettage and injection of BT-A both present major advantages compared with earlier methods. Subcutaneous curettage offers the same permanent efficacy but far fewer side-effects than sympathectomy, and less scarring than local excisional procedures, respectively. Of the conservative approaches BT-A is by far the most efficacious. Patients should be informed of the advantages and disadvantages of both methods.

Adult↗

PubMed2001

Initial experience with the stretta procedure for the treatment of gastroesophageal reflux disease.

BACKGROUND: The Stretta device (Curon Medical, Sunnyvale, CA) is a balloon-tipped four-needle catheter that delivers radiofrequency (RF) energy to the smooth muscle of the gastroesophageal junction. It can be used for the endoscopic treatment of gastroesophageal reflux disease (GERD). PATIENTS AND METHODS: Data prospectively collected on the first 25 consecutive patients undergoing the Stretta procedure at Vanderbilt University Medical Center between August 2000 and March 2001 are reported. Patient evaluation included esophageal manometry, ambulatory 24-hour pH testing, a standard GERD-specific quality-of-life survey (QOLRAD), a general quality-of-life survey (SF12), and endoscopy. Stretta surgery was performed following a standardized protocol. Thermocouple-controlled RF energy was delivered to the lower esophageal sphincter (LES) after endoscopic location of the z-line. Patients were followed up 3 months after endoscopic treatment. Results are presented as mean +/- SEM. RESULTS: Prior to treatment, patients had a mean DeMeester score of 31.0+/-11.4, an LES pressure of 24+/-2 mm Hg, and normal esophageal peristalsis. Of the 25 outpatient procedures, 19 were done under conscious sedation and 6 under general anesthesia. There was a small learning curve (76+/-8 min for the first three procedures; 50+/-2 min for the subsequent 22). The mild to moderate pain during the first 24 postoperative hours was controlled with over-the-counter medication. Two complications were noted: one patient presented with ulcerative esophagitis and gastroparesis 10 days after the Stretta treatment, and one patient developed pancreatitis on postoperative day 27, which was probably unrelated to the Stretta procedure. Eight of the thirteen patients (62%) available for 3-month follow-up were off all antisecretory medication. The other five patients were still taking medications but had been able to reduce the amount considerably. The average daily dose of proton pump inhibitors was 43.0+/-5.0 mg/preoperatively and 6.4+/-2.2 mg/3 months postoperatively (P < 0.001). Other classes of GERD treatment such as metoclopramide had been completely abandoned. In all patients, QOLRAD scores improved (3.5+/-0.4 to 5.5+/-0.5; P < 0.001) as did SF12 physical (23.7+/-3.0 to 31.0+/-3.4; P < 0.008) and mental (40.5+/-2.9 to 47.7+/-3.2, P < 0.017) scores. All patients would undergo a Stretta procedure again except one 78-year-old man with progressive Alzheimer's disease. CONCLUSION: The Stretta procedure is a promising new modality in the management of GERD. It can be safely performed in one short session with gastroesophageal endoscopy under conscious sedation in an outpatient setting. It improves GERD symptoms and quality-of-life scores in patients at 3 months and eliminates or significantly reduces the need for antisecretory drugs.

Adult↗

PubMed2000

17-alpha-ethinylestradiol affects reproduction, sexual differentiation and aromatase gene expression of the medaka (Oryzias latipes).

Juvenile medaka (Oryzias latipes) of the d-rR strain were exposed for 2 months to 1, 10 and 100 ng/l of the environmental estrogen 17-alpha-ethinylestradiol (EE(2)). The exposure period was followed by a 6 week recovering period in order to detect long-lasting effects on sexual differentiation. Survival rate, sex ratio, gonadal growth, spawning, fecundity, histology as well as the ovarian gene expression of aromatase were monitored. At 100 ng/l EE(2), all XY medaka were sex reversed and had developed an ovary. At lower EE(2) concentrations, which did not result in sex reversal, no alteration of testicular structure was detected and male fertility appeared to be unchanged. In XX females, reduced production of eggs was reflected in a significantly reduced gonadal weight at 10 and 100 ng/l EE(2). Aromatase, which in gonads is normally only expressed in ovaries, was detectable in testis of XY males exposed to 10 ng/l EE(2). The results indicated that a combination of different biological endpoints provide a suitable set of parameters for the biological evaluation of xenoestrogens, since the expression of molecular marker genes was not always paralleled by morphological deficiencies.

Journal Article↗

PubMed2000

Double ileoileal intussusception caused by a giant polypoid mass of heterotopic pancreas in a child.

UNLABELLED: Heterotopic pancreatic tissue has been found in several abdominal and intrathoracic locations. In the ileum, it is a rare, usually asymptomatic, incidental finding. CONCLUSION: A unique case of a recurrent ileoileal intussusception in an 11-year-old girl is presented caused by a giant polypoid mass composed of ectopic pancreatic tissue that remained undetected during several diagnostic tests during two previous admissions and laparoscopic abdominal exploration.

Abdominal Pain↗

PubMed2000

[Diagnostic and therapeutic consequences of kidney injuries in pediatric blunt abdominal trauma].

Renal lesions are frequently encountered in blunt pediatric abdominal trauma. In this retrospective study, we analyzed the incidence of renal trauma in these trauma patients to determine which diagnostic and therapeutic approaches were most predictive. From 1976 to 1996, 308 children sustaining blunt abdominal trauma were admitted to our department. Patients were evaluated using abdominal paracentesis, ultrasonography, and urinary analysis. In specific cases, i.v. urography, CT scan, and/or angiography were applied. We used the Organ Injury Scale (OIS) for classification of renal trauma into five grades. We encountered 69 serious abdominal traumas. Thirty-six patients sustained renal lesions grade 2 (G2) or higher; 20 children were polytraumatized. There were 67 renal lesions with 28 G1, 22 G2, 8 G3, 5 G4, 1 G5, and 3 lesions of the urinary tract. Ultrasonography and urinary analysis were found to be optimal diagnostic means for screening and observing the course of renal lesions. For lesions G2 or higher, CT scan was the most reliable in classifying and diagnosing renal lesions. This superseded i.v. urography. If no contrast medium was excreted in the CT scan, angiography was indicated. Only ten patients proceeded to operative therapy. During the period reviewed, a shift from operative to conservative treatment was notable with a tendency toward minimally invasive therapy. If lesions were G4 or G5, operative treatment was always indicated.

Abdominal Injuries↗

PubMed2000

Consequences of antigen self-presentation by tumor-specific cytotoxic T cells.

CD8-positive cytotoxic T cells (CTL) recognize antigenic peptides in combination with major histocompatibility complex (MHC) class I molecules on the surface of syngeneic antigen presenting cells (APC). In the present paper we show that cells from tumor antigen-specific CTL clones present their cognate antigenic peptide to other CTL from the same clone. Inter-CTL peptide presentation resulted in activation of the cells of one CTL clone to MHC-unrestricted lysis of bystander cells. In contrast to the behaviour of this clone, another CTL clone did not lyse bystander cells after incubation with the cognate peptide, but was activated to self-destruction. The human herpes virus Epstein-Barr virus is involved in the pathogenesis of a broad spectrum of human neoplasias. Using freshly established non-clonal T cells with specificity for a peptide derived from an Epstein-Barr virus encoded antigen we found again lysis of MHC mismatched bystander cells as a consequence of inter-CTL peptide presentation, indicating that bystander lysis following antigen self-presentation is not a phenomenon restricted to long-term in vitro cultured T cell clones. The potential implications for immunosurveillance against cancer and for tumor escape mechanisms are discussed.

Antigen Presentation↗

PubMed2000

Management of kidney injuries in children with blunt abdominal trauma.

BACKGROUND/PURPOSE: The authors analyzed the incidence and the course of renal injuries encountered in a cohort of pediatric patients with blunt abdominal trauma. This review focuses on the early diagnostic and therapeutic approach rather than the long-term outcome and draws conclusions for an effective initial management. METHODS: From 1976 to 1996, the charts of 308 children with blunt abdominal trauma that were admitted to the authors' department were reviewed. The patients initially were evaluated using urinalysis, ultrasonography, and abdominal paracentesis (until 1984) and in specific cases iv-urography, computed tomography (CT), and angiography. The authors retrospectively classified the renal trauma after the widely used Organ Injury Scaling (OIS) into 5 grades and correlated the diagnostic value of various techniques as well as the diagnostic approach. RESULTS: Sixty-nine serious abdominal traumas were encountered. Thirty-six patients suffered renal lesions grade 2 (G2) or higher; 20 children were polytraumatized. There were 67 renal lesions including 28 G1, 22 G2, 8 G3, 5 G4, 1 G5, and 3 lesions of the lower urinary tract. Ultrasonography and urinalysis were found to be the optimal diagnostic methods for screening and following the course of renal injury. CT scan proved to be most reliable for detecting and exactly classifying renal lesions grade 2 or higher and superseded consecutively iv-urography. In cases in which CT scan failed to show renal excretion of contrast agent, angiography was performed. Ten patients proceeded to operative therapy. CONCLUSIONS: Ultrasonography and urinalysis proved to be the optimal initial evaluation tool for excluding renal injury both as a screening method and for further controls. Exact classification was possible by CT scan. During the reviewed time period a shift from surgical to conservative management was notable. If lesions were G4 or G5, surgical treatment with tendency toward minimally invasive therapy always was indicated.

Abdominal Injuries↗

PubMed2000

Linear lesion formation by ND:YAG laser versus radiofrequency energy in porcine atria.

The efficacy of RF energy versus the neodymium:yittrium aluminum-garnet laser to create linear lesions was compared in fresh ex vivo swine hearts. A total of 598 lesions were created in four locations: ostium of the pulmonary veins, trabeculated lateral left atrium, smooth posterior part of the right atrium, and the isthmus between the inferior vena cava and tricuspid valve. A 400-micron bare quartz fiber with CO2 cooling (distance to the tissue 5, 10, and 15 mm) and an RF ablation catheter (4-mm tip) were mechanically dragged over the tissue at speeds 0.5, 1.0, and 1.5 mm/s. A continuous and transmural ablation line was recorded as successful. A 100% success rate was achieved at the pulmonary veins and the isthmus at some settings of energy delivery by the laser and RF. In the thick posterior right atrium, RF resulted in transmural lesions only when associated with carbonization, while the laser produced successful ablation lines in 100% of the attempts. In the left atrium, because of the presence of prominent trabeculations, RF was unsuccessful at all settings of energy delivery. In contrast, deep photocoagulation by laser resulted in successful ablations in the left atrium in 100% of attempts. Lesion formation was faster by laser ablation and mean lesion width was at least 25% smaller with the laser than with RF. In conclusion, the formation of linear lesions at the isthmus and at the pulmonary veins was successful with the laser and RF. In the trabeculated left atrium and the thick posterior right atrium, only laser ablation was successful.

Animals↗

PubMed1999

Induction of CYP1A in primary cultures of rainbow trout (Oncorhynchus mykiss) liver cells: concentration-response relationships of four model substances.

The study aims to evaluate short-term teleost hepatocyte cultures to establish dose-response curves for CYP1A induction and to rank the relative potencies of xenobiotics. Hepatocytes isolated from rainbow trout (Oncorhynchus mykiss) were incubated in vitro in coculture with RTG-2 cells in serum-free, chemically defined medium. Concentration-dependent induction of cytochrome P4501A was observed after treatment of the hepatocytes for 48 h with one of the four polyaromatic hydrocarbons: 3-methylcholanthrene, benzo[a]pyrene, benz[a]anthracene, and beta-naphthoflavone. The induction response was assessed by measuring 7-ethoxyresorufin-O-deethylase (EROD) and 7-ethoxycoumarin-O-deethylase (ECOD). From the data, EC50 and maximal induction response values were calculated. The rank order of EC50 values differed among the four model compounds, depending on the endpoint parameter. EC50 values for EROD and ECOD also differed in comparison to published affinity data for mammalian arylhydrocarbon receptor. The results of this study indicate the potential of primary teleostean hepatocyte cultures for studies on induction potency and regulation of piscine cytochrome P4501A. A drawback, however, appears to be the pronounced interindividual variation of the quantitative response of the cells.

Animals↗

PubMed1998

Plant nuclear gene knockout reveals a role in plastid division for the homolog of the bacterial cell division protein FtsZ, an ancestral tubulin.

Little is known about the division of eukaryotic cell organelles and up to now neither in animals nor in plants has a gene product been shown to mediate this process. A cDNA encoding a homolog of the bacterial cell division protein FtsZ, an ancestral tubulin, was isolated from the eukaryote Physcomitrella patens and used to disrupt efficiently the genomic locus in this terrestrial seedless plant. Seven out of 51 transgenics obtained were knockout plants generated by homologous recombination; they were specifically impeded in plastid division with no detectable effect on mitochondrial division or plant morphology. Implications on the theory of endosymbiosis and on the use of reverse genetics in plants are discussed.

Amino Acid Sequence↗

PubMed1998

[The scientific development in dermatology in Germany in relation to the emigration of Jewish dermatologists during national socialism].

The anti-semitic laws let to the persecution of the Jews in Germany during the time of National Socialism. About 600 Jewish dermatologists had to suffer from the prohibition of their profession. 63% of them left Germany. The emigrants mainly preferred to move out to the U.S. The policy of coordination and elimination of the National Socialists led to the reappointment of dermatological chairs in universities. The National Socialists also forced the change in the boards of dermatological societies and the change of the editorial boards of dermatological journals. All papers of the three leading dermatological journals were analysed for the evaluation of the development of science. The assessment included the number of articles, the origin of the authors and the contents of articles (research, clinics, diagnostic, therapy). From 1933 to 1945 the number of papers per year decreased consequently, especially during the Second World War. During the whole time the number of German authors increased and the number of abroad living authors decreased. There was a very good and interesting international exchange of information in the journal "Archiv für Dermatologie und Syphilis". The activity reduced clearly after the beginning of the Second World War in 1939. The analysis of contents resulted in a reduction of basis science research and an orientation to the clinical research. Papers about therapeutical possibilities were always published. The emigration of Jewish dermatologists led to a continuous reduction of scientific activities and to an extensive international isolation.

Dermatology↗

PubMed1998

Juvenile arthritis: genetic update.

Juvenile arthritis (JA) is a term that covers a number of different disease entities, of which only three present with significant Human Leukocyte Antigen (HLA) associations. (1) Pauciarticular JA with late onset and a strong male proponderance is associated with HLA-B27 and represents the group of juvenile spondyloarthropathies related to adult ankylosing spondylitis. (2) Early onset pauciarticular JA with a preponderance of females and a frequent occurance of chronic iridocyclitis and the frequent presence of anti-nuclear antibodies is associated with alleles from three different regions of the HLA system: HLA-A2, which shows a very strong correlation with early age of onset; DR8, DR11 and DR12 as well as DQA1*0401, *0501, *0601 and finally DPB1*0201. These alleles show no linkage disequilibrium in the control population. (3) Rheumatoid factor positive polyarticular JA is associated, as is adult rheumatoid arthritis, with DR4. Concerning the possible mechanisms of the immunopathogenesis, it is speculated that the normal function of HLA molecules, namely the presentation of antigenic peptides, plays a major role. Data collected on HLA associations in early onset pauciarticular JA have been interpreted as indicating that alleles of the DQA1 locus (*0401, *0501, *0601) are probably responsible for presenting the hypothetical arthritogenic peptides. It is speculated that the pathogenic process includes the presentation of HLA-A2 or HLA-DPB1*0201 derived peptides presented by DQ molecules. It is clearly stated that typing for HLA alleles has very little or no importance for clinical diagnosis and prognosis.

Arthritis, Juvenile↗

PubMed1998

A vigorous virus-specific CD4+ T cell response may contribute to the association of HLA-DR13 with viral clearance in hepatitis B.

A strong virus-specific CD4+ and CD8+ T lymphocyte response to hepatitis B virus (HBV) has been associated with viral clearance, but little is known about factors determining the individual's ability to mount such a T cell response. Recently a strong association between the HLA class II allele DR13 and a self-limited course of HBV infection has been described. In the present study of 33 patients with acute hepatitis B we show that individuals carrying HLA-DR13 mount a more vigorous CD4+ T cell response to HBV core (5706 ct/min (25th/75th percentile 3239 ct/min; 10,552 ct/min)) than patients without HLA-DR 13 (1365 ct/min (490 ct/min; 5334 ct/min); P = 0.006). However, peptide epitopes aa 50-69, aa 61-85, and aa 81-105 were recognized most frequently by both patient groups. Moreover, among 14 HBV core-specific CD4+ T cell clones from two patients with HLA-DR13, only one T cell clone was HLA-DR13-restricted. Our data suggest that the beneficial effect of the HLA-DR13 alleles on the outcome of HBV infection could be explained by a more vigorous HBV core-specific CD4+ T cell response, which may either be due to more proficient antigen presentation by the HLA-DR13 molecules themselves or a linked polymorphism in a neighbouring immunoregulatory gene.

Acute Disease↗

PubMed1997

Opioid effects on macrovascular dopamine release.

Both alkaloid opiates and met-enkephalin occur in vertebrate chromaffin cells, where they affect catecholamine (CA) secretion. Since the large blood vessels of the eel and the rat release dopamine (DA) from as yet unidentified source(s), we studied the impact of alkaloid opiates and met-enkephalin on the secretion of DA from three macrovessels of the American eel (Anguilla rostrata) in a perifusion system. Codeine, morphine, and met-enkephalin increased the release of DA from both the ventral aorta and the caudal vein. The antagonist naloxone stimulated DA release from the caudal vein, but had no impact on release from the ventral aorta. Only codeine had a significant effect on DA release from the posterior cardinal vein. These findings show that the DA release from the macrovessels is sensitive to opioid substances, and they suggest that the antagonistic effects between alkaloid opiate and opioid peptide, seen in other systems, are absent in large blood vessels. Furthermore, the "unorthodox" stimulatory effect of naloxone in the caudal vein raises the question of as yet unidentified receptor and/or effector systems.

Analgesics, Opioid↗

PubMed1997

Cholinergic control of catecholamine release in the eel.

The perifused posterior cardinal vein of the American eel (Anguilla rostrata) releases spontaneously dopamine (DA), norepinephrine (NE), and epinephrine (E). NE and E are secreted by innervated chromaffin cells, while DA is most likely released from a component of the vascular wall. Stimulation with acetylcholine strongly enhances the release of DA and E, and to a lesser degree the release of NE. Nicotine stimulates the release of all three catecholamines. Muscarine reduces the basal release of NE. Muscarine does not prevent nicotinic stimulation of NE and E release, but abolishes the nicotine effect on DA release. The muscarinic antagonist atropine stimulates the release of NE, but not of DA and E. The beta-adrenergic receptor antagonist propranolol suppresses the acetylcholine-stimulated release of NE and E, and reduces the DA response. From these findings, it appears that (1) nicotinic receptors regulate NE and E secretion from the chromaffin cells, (2) muscarinic receptors inhibit basal NE release, and (3) acetylcholine-stimulated release of NE and E requires the interaction with adrenergic receptors. On the other hand, DA release involves both nicotinic and adrenergic receptors, while the reduction of nicotine-stimulated (but not basal) DA release involves muscarinic receptors.

Acetylcholine↗